Development of second generation peptides modulating cellular adiponectin receptor responses

NASA Astrophysics Data System (ADS)

Otvos, Laszlo; Knappe, Daniel; Hoffmann, Ralf; Kovalszky, Ilona; Olah, Julia; Hewitson, Tim; Stawikowska, Roma; Stawikowski, Maciej; Cudic, Predrag; Lin, Feng; Wade, John; Surmacz, Eva; Lovas, Sandor

2014-10-01

The adipose tissue participates in the regulation of energy homeostasis as an important endocrine organ that secretes a number of biologically active adipokines, including adiponectin. Recently we developed and characterized a first-in-class peptide-based adiponectin receptor agonist by using in vitro and in vivo models of glioblastoma and breast cancer (BC). In the current study, we further explored the effects of peptide ADP355 in additional cellular models and found that ADP355 inhibited chronic myeloid leukemia (CML) cell proliferation and renal myofibroblast differentiation with mid-nanomolar IC50 values. According to molecular modeling calculations, ADP355 was remarkably flexible in the global minimum with a turn present in the middle of the peptide. Considering these structural features of ADP355 and the fact that adiponectin normally circulates as multimeric complexes, we developed and tested the activity of a linear branched dimer (ADP399). The dimer exhibited approximately 20-fold improved cellular activity inhibiting K562 CML and MCF-7 cell growth with high pM - low nM relative IC50 values. Biodistribution studies suggested superior tissue dissemination of both peptides after subcutaneous administration relative to intraperitoneal inoculation. After screening of a 397-member adiponectin active site library, a novel octapeptide (ADP400) was designed that counteracted 10-1000 nM ADP355- and ADP399-mediated effects on CML and BC cell growth at nanomolar concentrations. ADP400 induced mitogenic effects in MCF-7 BC cells perhaps due to antagonizing endogenous adiponectin actions or acting as an inverse agonist. While the linear dimer agonist ADP399 meets pharmacological criteria of a contemporary peptide drug lead, the peptide showing antagonist activity (ADP400) at similar concentrations will be an important target validation tool to study adiponectin functions.

Antiviral Evaluation of Octadecyloxyethyl Esters of (S)-3-Hydroxy-2-(phosphonomethoxy)propyl Nucleosides Against Herpesviruses and Orthopoxviruses≠

PubMed Central

Valiaeva, Nadejda; Prichard, Mark N.; Buller, R. Mark; Beadle, James R.; Hartline, Caroll B.; Keith, Kathy A.; Schriewer, Jill; Trahan, Julissa; Hostetler, Karl Y.

2009-01-01

Our previous studies showed that esterification of (S)-3-hydroxy-2-(phosphono-methoxy)propyl]adenine (HPMPA) or 1-(S)-[3-hydroxy-2-(phosphonomethoxy)-propyl]cytosine (HPMPC) with alkoxyalkyl groups such as hexadecyloxypropyl (HDP) or octadecyloxyethyl (ODE) resulted in large increases in antiviral activity and oral bioavailability. The HDP- and ODE- esters of HPMPA were shown to be active in cells infected with human immunodeficiency virus, type 1 (HIV-1), while HPMPA itself was virtually inactive. To explore this approach in greater detail, we synthesized four new compounds in this series, the ODE esters of 9-(S)-[3-hydroxy-2-(phosphonomethoxy)-propyl]guanine (HPMPG), 1-(S)-[3-hydroxy-2-(phosphono-methoxy)propyl]thymine (HPMPT), 9-(S)-[3-hydroxy-2-(phosphonomethoxy)propyl]-2,6-diaminopurine (HPMPDAP) and 9-(S)-[3-hydroxy-2-(phosphonomethoxy)propyl]-2-amino-6-cyclopropylaminopurine. (HPMP-cPrDAP) and evaluated their antiviral activity against herpes simplex virus, type 1 (HSV-1), human cytomegalovirus (HCMV), and vaccinia, cowpox and ectromelia. Against HSV-1, subnanomolar EC50 values were observed with ODE-HPMPA and ODE-HPMPC while ODE-HPMPG had intermediate antiviral activity with an EC50 of 40 nanomolar. In HFF cells infected with HCMV, the lowest EC50 values were observed with ODE-HPMPC, 0.9 nanomolar. ODE -HPMPA was highly active with an EC50 of 3 nanomolar, while ODE-HPMPG and ODE-HPMPDAP were also highly active with EC50s of 22 and 77 nanomolar, respectively. Against vaccinia and cowpox viruses, ODE-HPMPG and ODE-HPMPDAP were the most active and selective compounds with EC50 values of 20 to 60 nanomolar and selectivity index values of 600 to 3,500. ODE-HPMPG was also active against ectromelia virus with an EC50 value of 410 nanomolar and a selectivity index value of 166. ODE-HPMPG and ODE-HPMPDAP are proposed for further preclinical evaluation as possible candidates for treatment of HSV, HCMV or orthopoxvirus diseases. PMID:19800369

Benzyloxynitrostyrene analogues - A novel class of selective and highly potent inhibitors of monoamine oxidase B.

PubMed

Van der Walt, Mietha M; Terre'Blanche, Gisella; Petzer, Jacobus P; Petzer, Anél

2017-01-05

This study examines a series of novel 3-benzyloxy-β-nitrostyrene analogues as a novel class of inhibitors of the monoamine oxidase (MAO) enzymes. MAO inhibitors are considered useful for the treatment of depression and Parkinson's disease, and have recently attracted attention as potential therapeutic agents for a range of disorders including Alzheimer's disease, prostate cancer and certain cardiomyopathies. This study shows that the 3-benzyloxy-β-nitrostyrene analogues are potent inhibitors of the MAO-B isoform with IC 50 values in the nanomolar range (39-565 nM). Significantly, effectiveness towards MAO-B inhibition seems to be governed by the introduction of a 4″-fluoro-substituent on the benzyloxy ring, with compound 2b exhibiting the highest degree of MAO-B inhibition potency (IC 50  = 0.039 μM) and selectivity (SI = 166) among the compounds investigated. Since some of the 3-benzyloxy-β-nitrostyrene analogues possess potencies that are comparable to that of the reversible inhibitor, safinamide (IC 50  = 0.080 μM), it may be concluded that this class may be promising leads for the development of reversible and selective MAO-B inhibitors, that may be useful for the management of Parkinson's disease. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Antiprotozoal activity of proton-pump inhibitors.

PubMed

Pérez-Villanueva, Jaime; Romo-Mancillas, Antonio; Hernández-Campos, Alicia; Yépez-Mulia, Lilián; Hernández-Luis, Francisco; Castillo, Rafael

2011-12-15

Parasitic diseases are still a major health problem in developing countries. In our effort to find new antiparasitic agents, in this Letter we report the in vitro antiprotozoal activity of omeprazole, lansoprazole, rabeprazole and pantoprazole against Trichomonas vaginalis, Giardia intestinalis and Entamoeba histolytica. Molecular modeling studies were an important tool to highlight the potential antiprotozoal activity of these drugs. Experimental evaluations revealed a strong activity for all compounds tested. Rabeprazole and pantoprazole were the most active compounds, having IC(50) values in the nanomolar range, which were even better than metronidazole, the drug of choice for these parasites. Copyright © 2011 Elsevier Ltd. All rights reserved.

Identification of flubendazole as potential anti-neuroblastoma compound in a large cell line screen.

PubMed

Michaelis, Martin; Agha, Bishr; Rothweiler, Florian; Löschmann, Nadine; Voges, Yvonne; Mittelbronn, Michel; Starzetz, Tatjana; Harter, Patrick N; Abhari, Behnaz A; Fulda, Simone; Westermann, Frank; Riecken, Kristoffer; Spek, Silvia; Langer, Klaus; Wiese, Michael; Dirks, Wilhelm G; Zehner, Richard; Cinatl, Jaroslav; Wass, Mark N; Cinatl, Jindrich

2015-02-03

Flubendazole was shown to exert anti-leukaemia and anti-myeloma activity through inhibition of microtubule function. Here, flubendazole was tested for its effects on the viability of in total 461 cancer cell lines. Neuroblastoma was identified as highly flubendazole-sensitive cancer entity in a screen of 321 cell lines from 26 cancer entities. Flubendazole also reduced the viability of five primary neuroblastoma samples in nanomolar concentrations thought to be achievable in humans and inhibited vessel formation and neuroblastoma tumour growth in the chick chorioallantoic membrane assay. Resistance acquisition is a major problem in high-risk neuroblastoma. 119 cell lines from a panel of 140 neuroblastoma cell lines with acquired resistance to various anti-cancer drugs were sensitive to flubendazole in nanomolar concentrations. Tubulin-binding agent-resistant cell lines displayed the highest flubendazole IC50 and IC90 values but differences between drug classes did not reach statistical significance. Flubendazole induced p53-mediated apoptosis. The siRNA-mediated depletion of the p53 targets p21, BAX, or PUMA reduced the neuroblastoma cell sensitivity to flubendazole with PUMA depletion resulting in the most pronounced effects. The MDM2 inhibitor and p53 activator nutlin-3 increased flubendazole efficacy while RNAi-mediated p53-depletion reduced its activity. In conclusion, flubendazole represents a potential treatment option for neuroblastoma including therapy-refractory cells.

Identification of flubendazole as potential anti-neuroblastoma compound in a large cell line screen

PubMed Central

Michaelis, Martin; Agha, Bishr; Rothweiler, Florian; Löschmann, Nadine; Voges, Yvonne; Mittelbronn, Michel; Starzetz, Tatjana; Harter, Patrick N.; Abhari, Behnaz A.; Fulda, Simone; Westermann, Frank; Riecken, Kristoffer; Spek, Silvia; Langer, Klaus; Wiese, Michael; Dirks, Wilhelm G.; Zehner, Richard; Cinatl, Jaroslav; Wass, Mark N.; Cinatl, Jindrich

2015-01-01

Flubendazole was shown to exert anti-leukaemia and anti-myeloma activity through inhibition of microtubule function. Here, flubendazole was tested for its effects on the viability of in total 461 cancer cell lines. Neuroblastoma was identified as highly flubendazole-sensitive cancer entity in a screen of 321 cell lines from 26 cancer entities. Flubendazole also reduced the viability of five primary neuroblastoma samples in nanomolar concentrations thought to be achievable in humans and inhibited vessel formation and neuroblastoma tumour growth in the chick chorioallantoic membrane assay. Resistance acquisition is a major problem in high-risk neuroblastoma. 119 cell lines from a panel of 140 neuroblastoma cell lines with acquired resistance to various anti-cancer drugs were sensitive to flubendazole in nanomolar concentrations. Tubulin-binding agent-resistant cell lines displayed the highest flubendazole IC50 and IC90 values but differences between drug classes did not reach statistical significance. Flubendazole induced p53-mediated apoptosis. The siRNA-mediated depletion of the p53 targets p21, BAX, or PUMA reduced the neuroblastoma cell sensitivity to flubendazole with PUMA depletion resulting in the most pronounced effects. The MDM2 inhibitor and p53 activator nutlin-3 increased flubendazole efficacy while RNAi-mediated p53-depletion reduced its activity. In conclusion, flubendazole represents a potential treatment option for neuroblastoma including therapy-refractory cells. PMID:25644037

Novel coumarin derivatives bearing N-benzyl pyridinium moiety: potent and dual binding site acetylcholinesterase inhibitors.

PubMed

Alipour, Masoumeh; Khoobi, Mehdi; Foroumadi, Alireza; Nadri, Hamid; Moradi, Alireza; Sakhteman, Amirhossein; Ghandi, Mehdi; Shafiee, Abbas

2012-12-15

A novel series of coumarin derivatives linked to benzyl pyridinium group were synthesized and biologically evaluated as inhibitors of both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). The enzyme inhibitory activity of synthesized compounds was measured using colorimetric Ellman's method. It was revealed that compounds 3e, 3h, 3l, 3r and 3s have shown higher activity compared with donepezil hydrochloride as standard drug. Most of the compounds in these series had nanomolar range IC(50) in which compound 3r (IC(50) = 0.11 nM) was the most active compound against acetylcholinesterase enzyme. Copyright © 2012 Elsevier Ltd. All rights reserved.

Thiocoraline alters neuroendocrine phenotype and activates the Notch pathway in MTC-TT cell line

PubMed Central

Tesfazghi, Sara; Eide, Jacob; Dammalapati, Ajitha; Korlesky, Colin; Wyche, Thomas P; Bugni, Tim S; Chen, Herbert; Jaskula-Sztul, Renata

2013-01-01

Medullary thyroid cancer (MTC) is an aggressive neuroendocrine tumor (NET). Previous research has shown that activation of Notch signaling has a tumor suppressor role in NETs. The potential therapeutic effect of thiocoraline on the activation of the Notch pathway in an MTC cell line (TT) was investigated. Thiocoraline was isolated from a marine bacterium Verrucosispora sp. MTT assay (3-[4, 5-dimethylthiazole-2-yl]-2, 5-diphenyltetrazolium bromide) was used to determine the IC50 value and to measure cell proliferation. Western blot revealed the expression of Notch isoforms, NET, and cell cycle markers. Cell cycle progression was validated by flow cytometry. The mRNA expression of Notch isoforms and downstream targets were measured using real-time PCR. The IC50 value for thiocoraline treatment in TT cells was determined to be 7.6 nmol/L. Thiocoraline treatment decreased cell proliferation in a dose- and time-dependent manner. The mechanism of growth inhibition was found to be cell cycle arrest in G1 phase. Thiocoraline activated the Notch pathway as demonstrated by the dose-dependent increase in mRNA and protein expression of Notch isoforms. Furthermore, treatment with thiocoraline resulted in changes in the expression of downstream targets of the Notch pathway (HES1, HES2, HES6, HEY1, and HEY2) and reduced expression of NET markers, CgA, and ASCL1. Thiocoraline is a potent Notch pathway activator and an inhibitor of MTC-TT cell proliferation at low nanomolar concentrations. These results provide exciting evidence for the use of thiocoraline as a potential treatment for intractable MTC. Thiocoraline is a potent Notch pathway activator and an inhibitor of medullary thyroid cancer cell line (MTC-TT) cell proliferation at low nanomolar concentrations. These results provide evidence for the use of thiocoraline as a potential treatment for intractable MTC. PMID:24403239

O-(Triazolyl)methyl carbamates as a novel and potent class of FAAH inhibitors

PubMed Central

Colombano, Giampiero; Albani, Clara; Ottonello, Giuliana; Ribeiro, Alison; Scarpelli, Rita; Tarozzo, Glauco; Daglian, Jennifer; Jung, Kwang-Mook; Piomelli, Daniele; Bandiera, Tiziano

2015-01-01

Inhibition of fatty acid amide hydrolase (FAAH) activity is under investigation as a valuable strategy for the treatment of several disorders, including pain and drug addiction. A number of potent FAAH inhibitors belonging to different chemical classes have been disclosed. O-aryl carbamates are one of the most representative families. In the search for novel FAAH inhibitors, we synthesized a series of O-(1,2,3-triazol-4-yl)methyl carbamate derivatives exploiting the copper-catalyzed [3 + 2] cycloaddition reaction between azides and alkynes (click chemistry). We explored structure-activity relationships within this new class of compounds and identified potent inhibitors of both rat and human FAAH with IC50 values in the single-digit nanomolar range. PMID:25338703

Potential Chemopreventive Agents Based on the Structure of the Lead Compound 2-Bromo-1-hydroxyphenazine, Isolated from Streptomyces sp., Strain CNS284

PubMed Central

Conda-Sheridan, Martin; Marler, Laura; Park, Eun-Jung; Kondratyuk, Tamara P.; Jermihov, Katherine; Mesecar, Andrew D.; Pezzuto, John M.; Asolkar, Ratnakar N.; Fenical, William; Cushman, Mark

2010-01-01

The isolation of 2-bromo-1-hydroxyphenazine from a marine Streptomyces sp., strain CNS284, and its activity against NFκB, suggested that a short and flexible route for the synthesis of this metabolite and a variety of phenazine analogues be developed. Numerous phenazines were subsequently prepared and evaluated as inducers of quinone reductase 1 (QR1) and inhibitors of quinone reductase 2 (QR2), NF-κB, and inducible nitric oxide synthase (iNOS). Several of the active phenazine derivatives displayed IC50 values vs. QR1 induction and QR2 inhibition in the nanomolar range, suggesting they may find utility as cancer chemopreventive agents. PMID:21105712

Copper (II) complexes of bidentate ligands exhibit potent anti-cancer activity regardless of platinum sensitivity status.

PubMed

Wehbe, Mohamed; Lo, Cody; Leung, Ada W Y; Dragowska, Wieslawa H; Ryan, Gemma M; Bally, Marcel B

2017-12-01

Insensitivity to platinum, either through inherent or acquired resistance, is a major clinical problem in the treatment of many solid tumors. Here, we explored the therapeutic potential of diethyldithiocarbamate (DDC), pyrithione (Pyr), plumbagin (Plum), 8-hydroxyquinoline (8-HQ), clioquinol (CQ) copper complexes in a panel of cancer cell lines that differ in their sensitivity to platins (cisplatin/carboplatin) using a high-content imaging system. Our data suggest that the copper complexes were effective against both platinum sensitive (IC 50  ~ 1 μM platinum) and insensitive (IC 50  > 5 μM platinum) cell lines. Furthermore, copper complexes of DDC, Pyr and 8-HQ had greater therapeutic activity compared to the copper-free ligands in all cell lines; whereas the copper-dependent activities of Plum and CQ were cell-line specific. Four of the copper complexes (Cu(DDC) 2 , Cu(Pyr) 2 , Cu(Plum) 2 and Cu(8-HQ) 2 ) showed IC 50 values less than that of cisplatin in all tested cell lines. The complex copper DDC (Cu(DDC) 2 ) was selected for in vivo evaluation due to its low nano-molar range activity in vitro and the availability of an injectable liposomal formulation. Liposomal (Cu(DDC) 2 ) was tested in a fast-growing platinum-resistant A2780-CP ovarian xenograft model and was found to achieve a statistically significant reduction (50%; p < 0.05) in tumour size. This work supports the potential use of copper-based therapeutics to treat cancers that are insensitive to platinum drugs.

Inhibitors of plasmodial serine hydroxymethyltransferase (SHMT): cocrystal structures of pyrazolopyrans with potent blood- and liver-stage activities.

PubMed

Witschel, Matthias C; Rottmann, Matthias; Schwab, Anatol; Leartsakulpanich, Ubolsree; Chitnumsub, Penchit; Seet, Michael; Tonazzi, Sandro; Schwertz, Geoffrey; Stelzer, Frank; Mietzner, Thomas; McNamara, Case; Thater, Frank; Freymond, Céline; Jaruwat, Aritsara; Pinthong, Chatchadaporn; Riangrungroj, Pinpunya; Oufir, Mouhssin; Hamburger, Matthias; Mäser, Pascal; Sanz-Alonso, Laura M; Charman, Susan; Wittlin, Sergio; Yuthavong, Yongyuth; Chaiyen, Pimchai; Diederich, François

2015-04-09

Several of the enzymes related to the folate cycle are well-known for their role as clinically validated antimalarial targets. Nevertheless for serine hydroxymethyltransferase (SHMT), one of the key enzymes of this cycle, efficient inhibitors have not been described so far. On the basis of plant SHMT inhibitors from an herbicide optimization program, highly potent inhibitors of Plasmodium falciparum (Pf) and Plasmodium vivax (Pv) SHMT with a pyrazolopyran core structure were identified. Cocrystal structures of potent inhibitors with PvSHMT were solved at 2.6 Å resolution. These ligands showed activity (IC50/EC50 values) in the nanomolar range against purified PfSHMT, blood-stage Pf, and liver-stage P. berghei (Pb) cells and a high selectivity when assayed against mammalian cell lines. Pharmacokinetic limitations are the most plausible explanation for lack of significant activity of the inhibitors in the in vivo Pb mouse malaria model.

Structure-based design, synthesis, and biological evaluation of novel pyrrolyl aryl sulfones: HIV-1 non-nucleoside reverse transcriptase inhibitors active at nanomolar concentrations.

PubMed

Artico, M; Silvestri, R; Pagnozzi, E; Bruno, B; Novellino, E; Greco, G; Massa, S; Ettorre, A; Loi, A G; Scintu, F; La Colla, P

2000-05-04

Pyrrolyl aryl sulfones (PASs) have been recently reported as a new class of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) inhibitors acting at the non-nucleoside binding site of this enzyme (Artico, M.; et al. J. Med. Chem. 1996, 39, 522-530). Compound 3, the most potent inhibitor within the series (EC(50) = 0.14 microM, IC(50) = 0.4 microM, and SI > 1429), was then selected as a lead compound for a synthetic project based on molecular modeling studies. Using the three-dimensional structure of RT cocrystallized with the alpha-APA derivative R95845, we derived a model of the RT/3 complex by taking into account previously developed structure-activity relationships. Inspection of this model and docking calculations on virtual compounds prompted the design of novel PAS derivatives and related analogues. Our computational approach proved to be effective in making qualitative predictions, that is in discriminating active versus inactive compounds. Among the compounds synthesized and tested, 20 was the most active one, with EC(50) = 0.045 microM, IC(50) = 0.05 microM, and SI = 5333. Compared with the lead 3, these values represent a 3- and 8-fold improvement in the cell-based and enzyme assays, respectively, together with the highest selectivity achieved so far in the PAS series.

Novel Selective Estrogen Receptor Ligand Conjugates Incorporating Endoxifen-Combretastatin and Cyclofenil-Combretastatin Hybrid Scaffolds: Synthesis and Biochemical Evaluation.

PubMed

Kelly, Patrick M; Keely, Niall O; Bright, Sandra A; Yassin, Bassem; Ana, Gloria; Fayne, Darren; Zisterer, Daniela M; Meegan, Mary J

2017-08-31

Nuclear receptors such as the estrogen receptors (ERα and ERβ) modulate the effects of the estrogen hormones and are important targets for design of innovative chemotherapeutic agents for diseases such as breast cancer and osteoporosis. Conjugate and bifunctional compounds which incorporate an ER ligand offer a useful method of delivering cytotoxic drugs to tissue sites such as breast cancers which express ERs. A series of novel conjugate molecules incorporating both the ER ligands endoxifen and cyclofenil-endoxifen hybrids covalently linked to the antimitotic and tubulin targeting agent combretastatin A-4 were synthesised and evaluated as ER ligands. A number of these compounds demonstrated pro-apoptotic effects, with potent antiproliferative activity in ER-positive MCF-7 breast cancer cell lines and low cytotoxicity. These conjugates displayed binding affinity towards ERα and ERβ isoforms at nanomolar concentrations e.g., the cyclofenil-amide compound 13e is a promising lead compound of a clinically relevant ER conjugate with IC 50 in MCF-7 cells of 187 nM, and binding affinity to ERα (IC 50 = 19 nM) and ERβ (IC 50 = 229 nM) while the endoxifen conjugate 16b demonstrates antiproliferative activity in MCF-7 cells (IC 50 = 5.7 nM) and binding affinity to ERα (IC 50 = 15 nM) and ERβ (IC 50 = 115 nM). The ER binding effects are rationalised in a molecular modelling study in which the disruption of the ER helix-12 in the presence of compounds 11e , 13e and 16b is presented These conjugate compounds have potential application for further development as antineoplastic agents in the treatment of ER positive breast cancers.

Optimization of tocotrienols as antiproliferative and antimigratory leads.

PubMed

Behery, Fathy A; Akl, Mohamed R; Ananthula, Suryatheja; Parajuli, Parash; Sylvester, Paul W; El Sayed, Khalid A

2013-01-01

The vitamin E family members γ- and δ-tocotrienols (2 and 3, respectively) are known natural products with documented anticancer activities. Redox-silent structural modifications, such as esterification, etherification and carbamoylation, of 2 and 3 significantly enhanced their anticancer activities. However, hit-to-lead optimization of tocotrienols and their analogs was yet to be reported at the outset of the project described herein. Subjecting the chroman ring of 2 and 3 to the electrophilic substitution reactions, namely, Mannich and Lederer-Manasse procedures, afforded 42 new products. These included the 3,4-dihydro-1,3-oxazines 3-29 and 35-44, Mannich bases 30-31, and the hydroxymethyl analogs 32-34. Of these, the δ-tocotrienol analogs 8, 11, 18, 24, 25, 27, and 40 inhibited the proliferation of the highly metastatic +SA mammary epithelial cancer cell line, with IC(50) values in the nanomolar (nM) range. In NCI's 60 human tumor cell line panel, 8, 17, 38, and 40 showed antiproliferative activity, with nM GI(50) values. The δ-tocotrienol analogs 10 and 38 inhibited the migration of the highly metastatic human breast cancer cell line MDA-MB-231 with IC(50) values of 1.3 and 1.5 μM, respectively, in the wound-healing assay. A dose of 0.5 mg/day for 14 days of one of the active analogs, 30, significantly slowed the growth of +SA mammary tumors in the syngeneic BALB/c mouse model, compared to the vehicle- and the parent γ-tocotrienol-treated control groups. Electrophilic substitution reactions promoted tocotrienols to lead level and can enable their future use to control metastatic breast malignancies. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Mosquitocidal carbamates with low toxicity to agricultural pests: an advantageous property for insecticide resistance management.

PubMed

Swale, Daniel R; Carlier, Paul R; Hartsel, Joshua A; Ma, Ming; Bloomquist, Jeffrey R

2015-08-01

Insecticide resistance in the malaria mosquito Anopheles gambiae is well documented, and widespread agricultural use of pyrethroids may exacerbate development of resistance when pyrethroids are used in vector control. We have developed carbamate anticholinesterases that possess a high degree of An. gambiae:human selectivity for enzyme inhibition. The purpose of this study was to assess the spectrum of activity of these carbamates against other mosquitoes and agricultural pests. Experimental carbamates were potent inhibitors of mosquito acetylcholinesterases, with IC50 values in the nanomolar range. Similar potencies were observed for Musca domestica and Drosophila melanogaster enzymes. Although meta-substituted carbamates were potent inhibitors, two ortho-substituted carbamates displayed poor enzyme inhibition (IC50 ≥ 10(-6)  M) in honey bee (Apis mellifera), Asian citrus psyllid (Diaphorina citri) and lepidopteran agricultural pests (Plutella xylostella and Ostrinia nubilalis). Enzyme inhibition results were confirmed by toxicity studies in caterpillars, where the new carbamates were 2-3-fold less toxic than propoxur and up to tenfold less active than bendiocarb, indicating little utility of these compounds for crop protection. The experimental carbamates were broadly active against mosquito species but not agricultural pests, which should mitigate selection for mosquito insecticide resistance by reducing agricultural uses of these compounds. © 2014 Society of Chemical Industry. © 2014 Society of Chemical Industry.

Effects of the tumor-vasculature-disrupting agent verubulin and two heteroaryl analogues on cancer cells, endothelial cells, and blood vessels.

PubMed

Mahal, Katharina; Resch, Marcus; Ficner, Ralf; Schobert, Rainer; Biersack, Bernhard; Mueller, Thomas

2014-04-01

Two analogues of the discontinued tumor vascular-disrupting agent verubulin (Azixa®, MPC-6827, 1) featuring benzo-1,4-dioxan-6-yl (compound 5 a) and N-methylindol-5-yl (compound 10) residues instead of the para-anisyl group on the 4-(methylamino)-2-methylquinazoline pharmacophore, were prepared and found to exceed the antitumor efficacy of the lead compound. They were antiproliferative with single-digit nanomolar IC50 values against a panel of nine tumor cell lines, while not affecting nonmalignant fibroblasts. Indole 10 surpassed verubulin in seven tumor cell lines including colon, breast, ovarian, and germ cell cancer cell lines. In line with docking studies indicating that compound 10 may bind the colchicine binding site of tubulin more tightly (Ebind =-9.8 kcal mol(-1) ) than verubulin (Ebind =-8.3 kcal mol(-1) ), 10 suppressed the formation of vessel-like tubes in endothelial cells and destroyed the blood vessels in the chorioallantoic membrane of fertilized chicken eggs at nanomolar concentrations. When applied to nude mice bearing a highly vascularized 1411HP germ cell xenograft tumor, compound 10 displayed pronounced vascular-disrupting effects that led to hemorrhages and extensive central necrosis in the tumor. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Repurposing Auranofin as a Lead Candidate for Treatment of Lymphatic Filariasis and Onchocerciasis

PubMed Central

Bulman, Christina A.; Bidlow, Chelsea M.; Lustigman, Sara; Cho-Ngwa, Fidelis; Williams, David; Rascón, Jr, Alberto A.; Tricoche, Nancy; Samje, Moses; Bell, Aaron; Suzuki, Brian; Lim, K. C.; Supakorndej, Nonglak; Supakorndej, Prasit; Wolfe, Alan R.; Knudsen, Giselle M.; Chen, Steven; Wilson, Chris; Ang, Kean-Hooi; Arkin, Michelle; Gut, Jiri; Franklin, Chris; Marcellino, Chris; McKerrow, James H.; Debnath, Anjan; Sakanari, Judy A.

2015-01-01

Two major human diseases caused by filariid nematodes are onchocerciasis, or river blindness, and lymphatic filariasis, which can lead to elephantiasis. The drugs ivermectin, diethylcarbamazine (DEC), and albendazole are used in control programs for these diseases, but are mainly effective against the microfilarial stage and have minimal or no effect on adult worms. Adult Onchocerca volvulus and Brugia malayi worms (macrofilariae) can live for up to 15 years, reproducing and allowing the infection to persist in a population. Therefore, to support control or elimination of these two diseases, effective macrofilaricidal drugs are necessary, in addition to current drugs. In an effort to identify macrofilaricidal drugs, we screened an FDA-approved library with adult worms of Brugia spp. and Onchocerca ochengi, third-stage larvae (L3s) of Onchocerca volvulus, and the microfilariae of both O. ochengi and Loa loa. We found that auranofin, a gold-containing drug used for rheumatoid arthritis, was effective in vitro in killing both Brugia spp. and O. ochengi adult worms and in inhibiting the molting of L3s of O. volvulus with IC50 values in the low micromolar to nanomolar range. Auranofin had an approximately 43-fold higher IC50 against the microfilariae of L. loa compared with the IC50 for adult female O. ochengi, which may be beneficial if used in areas where Onchocerca and Brugia are co-endemic with L. loa, to prevent severe adverse reactions to the drug-induced death of L. loa microfilariae. Further testing indicated that auranofin is also effective in reducing Brugia adult worm burden in infected gerbils and that auranofin may be targeting the thioredoxin reductase in this nematode. PMID:25700363

Structure-Based Design of Potent Bcl-2/Bcl-xL Inhibitors with Strong in Vivo Antitumor Activity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Haibin; Aguilar, Angelo; Chen, Jianfang

Bcl-2 and Bcl-xL are key apoptosis regulators and attractive cancer therapeutic targets. We have designed and optimized a class of small-molecule inhibitors of Bcl-2 and Bcl-xL containing a 4,5-diphenyl-1H-pyrrole-3-carboxylic acid core structure. A 1.4 {angstrom} resolution crystal structure of a lead compound, 12, complexed with Bcl-xL has provided a basis for our optimization. The most potent compounds, 14 and 15, bind to Bcl-2 and Bcl-xL with subnanomolar K{sub i} values and are potent antagonists of Bcl-2 and Bcl-xL in functional assays. Compounds 14 and 15 inhibit cell growth with low nanomolar IC{sub 50} values in multiple small-cell lung cancer cellmore » lines and induce robust apoptosis in cancer cells at concentrations as low as 10 nM. Compound 14 also achieves strong antitumor activity in an animal model of human cancer.« less

Discovery of new nanomolar inhibitors of GPa: Extension of 2-oxo-1,2-dihydropyridinyl-3-yl amide-based GPa inhibitors.

PubMed

Loughlin, Wendy A; Jenkins, Ian D; Karis, N David; Healy, Peter C

2017-02-15

Glycogen Phosphorylase (GP) is a functionally active dimeric enzyme, which is a target for inhibition of the conversion of glycogen to glucose-1-phosphate. In this study we report the design and synthesis of 14 new pyridone derivatives, and seek to extend the SAR analysis of these compounds. The SAR revealed the minor influence of the amide group, importance of the pyridone ring both spatially around the pyridine ring and for possible π-stacking, and confirmed a preference for inclusion of 3,4-dichlorobenzyl moieties, as bookends to the pyridone scaffold. Upon exploring a dimer strategy as part of the SAR analysis, the first extended 2-oxo-dihydropyridinyl-3-yl amide nanomolar based inhibitors of GPa (IC 50  = 230 and 260 nM) were identified. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Fragment growing and linking lead to novel nanomolar lactate dehydrogenase inhibitors.

PubMed

Kohlmann, Anna; Zech, Stephan G; Li, Feng; Zhou, Tianjun; Squillace, Rachel M; Commodore, Lois; Greenfield, Matthew T; Lu, Xiaohui; Miller, David P; Huang, Wei-Sheng; Qi, Jiwei; Thomas, R Mathew; Wang, Yihan; Zhang, Sen; Dodd, Rory; Liu, Shuangying; Xu, Rongsong; Xu, Yongjin; Miret, Juan J; Rivera, Victor; Clackson, Tim; Shakespeare, William C; Zhu, Xiaotian; Dalgarno, David C

2013-02-14

Lactate dehydrogenase A (LDH-A) catalyzes the interconversion of lactate and pyruvate in the glycolysis pathway. Cancer cells rely heavily on glycolysis instead of oxidative phosphorylation to generate ATP, a phenomenon known as the Warburg effect. The inhibition of LDH-A by small molecules is therefore of interest for potential cancer treatments. We describe the identification and optimization of LDH-A inhibitors by fragment-based drug discovery. We applied ligand based NMR screening to identify low affinity fragments binding to LDH-A. The dissociation constants (K(d)) and enzyme inhibition (IC(50)) of fragment hits were measured by surface plasmon resonance (SPR) and enzyme assays, respectively. The binding modes of selected fragments were investigated by X-ray crystallography. Fragment growing and linking, followed by chemical optimization, resulted in nanomolar LDH-A inhibitors that demonstrated stoichiometric binding to LDH-A. Selected molecules inhibited lactate production in cells, suggesting target-specific inhibition in cancer cell lines.

New 6- and 7-heterocyclyl-1H-indole derivatives as potent tubulin assembly and cancer cell growth inhibitors.

PubMed

La Regina, Giuseppe; Bai, Ruoli; Coluccia, Antonio; Naccarato, Valentina; Famiglini, Valeria; Nalli, Marianna; Masci, Domiziana; Verrico, Annalisa; Rovella, Paola; Mazzoccoli, Carmela; Da Pozzo, Eleonora; Cavallini, Chiara; Martini, Claudia; Vultaggio, Stefania; Dondio, Giulio; Varasi, Mario; Mercurio, Ciro; Hamel, Ernest; Lavia, Patrizia; Silvestri, Romano

2018-05-25

We designed new 3-arylthio- and 3-aroyl-1H-indole derivatives 3-22 bearing a heterocyclic ring at position 5, 6 or 7 of the indole nucleus. The 6- and 7-heterocyclyl-1H-indoles showed potent inhibition of tubulin polymerization, binding of colchicine to tubulin and growth of MCF-7 cancer cells. Compounds 13 and 19 inhibited a panel of cancer cells and the NCI/ADR-RES multidrug resistant cell line at low nanomolar concentrations. Compound 13 at 50 nM induced 77% G2/M in HeLa cells, and at 20 nM caused 50% stable arrest of mitosis. As an inhibitor of HepG2 cells (IC 50  = 20 nM), 13 was 4-fold superior to 19. Compound 13 was a potent inhibitor of the human U87MG glioblastoma cells at nanomolar concentrations, being nearly one order of magnitude superior to previously reported arylthioindoles. The present results highlight 13 as a robust scaffold for the design of new anticancer agents. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

N-Guanidino Derivatives of 1,5-Dideoxy-1,5-imino-d-xylitol are Potent, Selective, and Stable Inhibitors of β-Glucocerebrosidase.

PubMed

Sevšek, Alen; Šrot, Luka; Rihter, Jakob; Čelan, Maša; van Ufford, Linda Quarles; Moret, Ed E; Martin, Nathaniel I; Pieters, Roland J

2017-04-06

A series of lipidated guanidino and urea derivatives of 1,5-dideoxy-1,5-imino-d-xylitol were prepared from d-xylose using a concise synthetic protocol. Inhibition assays with a panel of glycosidases revealed that the guanidino analogues display potent inhibition against human recombinant β-glucocerebrosidase with IC 50 values in the low nanomolar range. Related urea analogues of 1,5-dideoxy-1,5-imino-d-xylitol were also synthesized and evaluated in the same fashion and found to be selective for β-galactosidase from bovine liver. No inhibition of human recombinant β-glucocerebrosidase was observed for the urea analogues. Computational studies provided insight into the potent activity of analogues bearing the substituted guanidine moiety in the inhibition of lysosomal glucocerebrosidase (GBA). © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Application of Receiver Operating Characteristic Analysis to Refine the Prediction of Potential Digoxin Drug Interactions

PubMed Central

Ellens, Harma; Deng, Shibing; Coleman, JoAnn; Bentz, Joe; Taub, Mitchell E.; Ragueneau-Majlessi, Isabelle; Chung, Sophie P.; Herédi-Szabó, Krisztina; Neuhoff, Sibylle; Palm, Johan; Balimane, Praveen; Zhang, Lei; Jamei, Masoud; Hanna, Imad; O’Connor, Michael; Bednarczyk, Dallas; Forsgard, Malin; Chu, Xiaoyan; Funk, Christoph; Guo, Ailan; Hillgren, Kathleen M.; Li, LiBin; Pak, Anne Y.; Perloff, Elke S.; Rajaraman, Ganesh; Salphati, Laurent; Taur, Jan-Shiang; Weitz, Dietmar; Wortelboer, Heleen M.; Xia, Cindy Q.; Xiao, Guangqing; Yamagata, Tetsuo

2013-01-01

In the 2012 Food and Drug Administration (FDA) draft guidance on drug-drug interactions (DDIs), a new molecular entity that inhibits P-glycoprotein (P-gp) may need a clinical DDI study with a P-gp substrate such as digoxin when the maximum concentration of inhibitor at steady state divided by IC50 ([I1]/IC50) is ≥0.1 or concentration of inhibitor based on highest approved dose dissolved in 250 ml divide by IC50 ([I2]/IC50) is ≥10. In this article, refined criteria are presented, determined by receiver operating characteristic analysis, using IC50 values generated by 23 laboratories. P-gp probe substrates were digoxin for polarized cell-lines and N-methyl quinidine or vinblastine for P-gp overexpressed vesicles. Inhibition of probe substrate transport was evaluated using 15 known P-gp inhibitors. Importantly, the criteria derived in this article take into account variability in IC50 values. Moreover, they are statistically derived based on the highest degree of accuracy in predicting true positive and true negative digoxin DDI results. The refined criteria of [I1]/IC50 ≥ 0.03 and [I2]/IC50 ≥ 45 and FDA criteria were applied to a test set of 101 in vitro-in vivo digoxin DDI pairs collated from the literature. The number of false negatives (none predicted but DDI observed) were similar, 10 and 12%, whereas the number of false positives (DDI predicted but not observed) substantially decreased from 51 to 40%, relative to the FDA criteria. On the basis of estimated overall variability in IC50 values, a theoretical 95% confidence interval calculation was developed for single laboratory IC50 values, translating into a range of [I1]/IC50 and [I2]/IC50 values. The extent by which this range falls above the criteria is a measure of risk associated with the decision, attributable to variability in IC50 values. PMID:23620486

Discovery of imidazopyridine derivatives as highly potent respiratory syncytial virus fusion inhibitors.

PubMed

Feng, Song; Hong, Di; Wang, Baoxia; Zheng, Xiufang; Miao, Kun; Wang, Lisha; Yun, Hongying; Gao, Lu; Zhao, Shuhai; Shen, Hong C

2015-03-12

A series of imidazolepyridine derivatives were designed and synthesized according to the established docking studies. The imidazopyridine derivatives were found to have good potency and physical-chemical properties. Several highly potent compounds such as 8ji, 8jl, and 8jm were identified with single nanomolar activities. The most potent compound 8jm showed an IC50 of 3 nM, lower microsome clearance and no CYP inhibition. The profile of 8jm appeared to be superior to BMS433771, and supported further optimization.

Discovery of Imidazopyridine Derivatives as Highly Potent Respiratory Syncytial Virus Fusion Inhibitors

PubMed Central

2015-01-01

A series of imidazolepyridine derivatives were designed and synthesized according to the established docking studies. The imidazopyridine derivatives were found to have good potency and physical-chemical properties. Several highly potent compounds such as 8ji, 8jl, and 8jm were identified with single nanomolar activities. The most potent compound 8jm showed an IC50 of 3 nM, lower microsome clearance and no CYP inhibition. The profile of 8jm appeared to be superior to BMS433771, and supported further optimization. PMID:25941547

Discovery of Potent VEGFR-2 Inhibitors based on Furopyrimidine and Thienopyrimidne Scaffolds as Cancer Targeting Agents

NASA Astrophysics Data System (ADS)

Aziz, Marwa A.; Serya, Rabah A. T.; Lasheen, Deena S.; Abdel-Aziz, Amal Kamal; Esmat, Ahmed; Mansour, Ahmed M.; Singab, Abdel Nasser B.; Abouzid, Khaled A. M.

2016-04-01

Vascular endothelial growth factor receptor-2 (VEGFR-2) plays a crucial role in cancer angiogenesis. In this study, a series of novel furo[2,3-d]pyrimidine and thieno[2,3-d]pyrimidine based-derivatives were designed and synthesized as VEGFR-2 inhibitors, in accordance to the structure activity relationship (SAR) studies of known type II VEGFR-2 inhibitors. The synthesized compounds were evaluated for their ability to in vitro inhibit VEGFR-2 kinase enzyme. Seven compounds (15b, 16c, 16e, 21a, 21b, 21c and 21e) demonstrated highly potent dose-related VEGFR-2 inhibition with IC50 values in nanomolar range, of which the thieno[2,3-d]pyrimidine based-derivatives (21b, 21c and 21e) exhibited IC50 values of 33.4, 47.0 and 21 nM respectively. Moreover, furo[2,3-d]pyrimidine-based derivative (15b) showed the strongest inhibition of human umbilical vein endothelial cells (HUVEC) proliferation with 99.5% inhibition at 10 μM concentration. Consistent with our in vitro findings, compounds (21b and 21e) orally administered at 5 and 10 mg/kg/day for 8 consecutive days demonstrated potent anticancer activity in Erhlich ascites carcinoma (EAC) solid tumor murine model. Such compounds blunted angiogenesis in EAC as evidenced by reduced percent microvessel via decreasing VEGFR-2 phosphorylation with subsequent induction of apoptotic machinery. Furthermore, Miles vascular permeability assay confirmed their antiangiogenic effects in vivo. Intriguingly, such compounds showed no obvious toxicity.

The Design and Development of Potent Small Molecules as Anticancer Agents Targeting EGFR TK and Tubulin Polymerization

PubMed Central

Ihmaid, Saleh; Ahmed, Hany E. A.; Zayed, Mohamed F.

2018-01-01

Some novel anthranilate diamides derivatives 4a–e, 6a–c and 9a–d were designed and synthesized to be evaluated for their in vitro anticancer activity. Structures of all newly synthesized compounds were confirmed by infra-red (IR), high-resolution mass (HR-MS) spectra, 1H nuclear magnetic resonance (NMR) and 13C nuclear magnetic resonance (NMR) analyses. Cytotoxic screening was performed according to (3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide) tetrazolium (MTT) assay method using erlotinib as a reference drug against two different types of breast cancer cells. The molecular docking study was performed for representative compounds against two targets, epidermal growth factor receptor (EGFR) and tubulin in colchicine binding site to assess their binding affinities in order to rationalize their anticancer activity in a qualitative way. The data obtained from the molecular modeling was correlated with that obtained from the biological screening. These data showed considerable anticancer activity for these newly synthesized compounds. Biological data for most of the anthranilate diamide showed excellent activity with nanomolar or sub nanomolar half maximal inhibitory concentration (IC50) values against tumor cells. EGFR tyrosine kinase (TK) inhibition assay, tubulin inhibition assay and apoptosis analysis were performed for selected compounds to get more details about their mechanism of action. Extensive structure activity relationship (SAR) analyses were also carried out. PMID:29385728

Antidepressant-like responses to the combined sigma and 5-HT1A receptor agonist OPC-14523.

PubMed

Tottori, K; Miwa, T; Uwahodo, Y; Yamada, S; Nakai, M; Oshiro, Y; Kikuchi, T; Altar, C A

2001-12-01

The antidepressant-like activity of a novel compound, OPC-14523, was investigated in comparison with the conventional antidepressants, fluoxetine and imipramine. OPC-14523 bound with nanomolar affinities to sigma receptors (IC(50)=47-56 nM), the 5-HT(1A) receptor (IC(50)=2.3 nM), and the 5-HT transporter (IC(50)=80 nM). OPC-14523 inhibited the in vitro reuptake of 3H-5-HT (IC(50)=27 nM), but it showed very weak inhibitory activity on 3H-NE and 3H-DA reuptake. OPC-14523 did not inhibit MAO A or B activities or muscarinic receptors. A single oral administration of OPC-14523 produced a marked antidepressant-like effect in the forced swimming test (FST) with rats (ED(50)=27 mg/kg) and mice (ED(50)=20mg/kg) without affecting the general locomotor activity. In contrast, fluoxetine and imipramine each required at least four days of repeated dosing to show this activity. The acute activity of OPC-14523 was blocked by pretreatment with the sigma receptor antagonist NE-100 or the selective 5-HT(1A) receptor antagonist WAY-100635. The induction of flat body posture by OPC-14523 was blocked by the selective 5-HT(1A) receptor antagonist NAN-190, and forebrain 5-HT biosynthesis was attenuated by OPC-14523 at behaviorally effective doses. In contrast, OPC-14523, unlike fluoxetine, failed to inhibit 5-HT reuptake at oral doses below 100mg/kg. Thus, the acute antidepressant-like action of OPC-14523 is achieved by the combined stimulation of sigma and 5-HT(1A) receptors without inhibition of 5-HT reuptake in vivo.

Optimization of benzoxazole-based inhibitors of Cryptosporidium parvum inosine 5′-monophosphate dehydrogenase

PubMed Central

Gorla, Suresh Kumar; Kavitha, Mandapati; Zhang, Minjia; Chin, James En Wai; Liu, Xiaoping; Striepen, Boris; Makowska-Grzyska, Magdalena; Kim, Youngchang; Joachimiak, Andrzej; Hedstrom, Lizbeth; Cuny, Gregory D.

2013-01-01

Cryptosporidium parvum is an enteric protozoan parasite that has emerged as a major cause of diarrhea, malnutrition and gastroenteritis as well as posing a potential bioterrorism threat. C. parvum synthesizes guanine nucleotides from host adenosine in a streamlined pathway that relies on inosine 5′-monophosphate dehydrogenase (IMPDH). We have previously identified several parasite-selective C. parvum IMPDH (CpIMPDH) inhibitors by high-throughput screening. In this paper, we report the structure-activity relationship (SAR) for a series of benzoxazole derivatives with many compounds demonstrating CpIMPDH IC50 values in the nanomolar range and > 500-fold selectivity over human IMPDH (hIMPDH). Unlike previously reported CpIMPDH inhibitors, these compounds are competitive inhibitors versus NAD+. The SAR study reveals that pyridine and other small heteroaromatic substituents are required at the 2-position of the benzoxazole for potent inhibitory activity. In addition, several other SAR conclusions are highlighted with regard to the benzoxazole and the amide portion of the inhibitor, including preferred stereochemistry. An x-ray crystal structure of a representative E•IMP•inhibitor complex is also presented. Overall, the secondary amine derivative 15a (Q67) demonstrated excellent CpIMPDH inhibitory activity (IC50 = 0.5 ± 0.1 nM) and moderate stability (t1/2 = 44 min) in mouse liver microsomes. Compound 73, the racemic version of 15a, also displayed superb antiparasitic activity in a Toxoplasma gondii strain that relies on CpIMPDH (EC50 = 20 ± 20 nM), and selectivity versus a wild-type T. gondii strain (200-fold). No toxicity was observed (LD50 > 50 μM) against a panel of four mammalian cells lines. PMID:23668331

Inhibition of monoamine oxidase A and B activities by imidazol(ine)/guanidine drugs, nature of the interaction and distinction from I2-imidazoline receptors in rat liver

PubMed Central

Ozaita, Andrés; Olmos, Gabriel; Assumpció Boronat, M; Miguel Lizcano, José; Unzeta, Mercedes; García-Sevilla, Jesús A

1997-01-01

I2-Imidazoline sites ([3H]-idazoxan binding) have been identified on monoamine oxidase (MAO) and proposed to modulate the activity of the enzyme through an allosteric inhibitory mechanism (Tesson et al., 1995). The main aim of this study was to assess the inhibitory effects and nature of the inhibition of imidazol(ine)/guanidine drugs on rat liver MAO-A and MAO-B isoforms and to compare their inhibitory potencies with their affinities for the sites labelled by [3H]-clonidine in the same tissue. Competition for [3H]-clonidine binding in rat liver mitochondrial fractions by imidazol(ine)/guanidine compounds revealed that the pharmacological profile of the interaction (2 - styryl - 2 - imidazoline, LSL 61112>idazoxan>2 - benzofuranyl - 2 - imidazoline, 2-BFI=cirazoline>guanabenz>oxymetazoline>>clonidine) was typical of that for I2-sites. Clonidine inhibited rat liver MAO-A and MAO-B activities with very low potency (IC50s: 700 μM and 6 mM, respectively) and displayed the typical pattern of competitive enzyme inhibition (Lineweaver-Burk plots: increased Km and unchanged Vmax values). Other imidazol(ine)/guanidine drugs also were weak MAO inhibitors with the exception of guanabenz, 2-BFI and cirazoline on MAO-A (IC50s: 4–11 μM) and 2-benzofuranyl-2-imidazol (LSL 60101) on MAO-B (IC50: 16 μM). Idazoxan was a full inhibitor, although with rather low potency, on both MAO-A and MAO-B isoenzymes (IC50s: 280 μM and 624 μM, respectively). Kinetic analyses of MAO-A inhibition by these drugs revealed that the interactions were competitive. For the same drugs acting on MAO-B the interactions were of the mixed type inhibition (increased Km and decreased Vmax values), although the greater inhibitory effects on the apparent value of Vmax/Km than on the Vmax value indicated that the competitive element of the MAO-B inhibition predominated. Competition for [3H]-Ro 41-1049 binding to MAO-A or [3H]-Ro 19-6327 binding to MAO-B in rat liver mitochondrial fractions by imidazol(ine)/guanidine compounds revealed that the drug inhibition constants (Ki values) were similar to the IC50 values displayed for the inhibition of MAO-A or MAO-B activities. In fact, very good correlations were obtained when the affinities of drugs at MAO-A or MAO-B catalytic sites were correlated with their potencies in inhibiting MAO-A (r=0.92) or MAO-B (r=0.99) activity. This further suggested a direct drug interaction with the catalytic sites of MAO-A and MAO-B isoforms. No significant correlations were found when the potencies of imidazol(ine)/guanidine drugs at the high affinity site (pKiH, nanomolar range) or the low-affinity site (pKiL, micromolar range) of I2-imidazoline receptors labelled with [3H]-clonidine were correlated with the pIC50 values of the same drugs for inhibition of MAO-A or MAO-B activity. These discrepancies indicated that I2-imidazoline receptors are not directly related to the site of action of these drugs on MAO activity in rat liver mitochondrial fractions. Although these studies cannot exclude the presence of additional binding sites on MAO that do not affect the activity of the enzyme, they would suggest that I2-imidazoline receptors represent molecular species that are distinct from MAO. PMID:9222546

Design, synthesis and biological evaluations of N-Hydroxy thienopyrimidine-2,4-diones as inhibitors of HIV reverse transcriptase-associated RNase H.

PubMed

Kankanala, Jayakanth; Kirby, Karen A; Huber, Andrew D; Casey, Mary C; Wilson, Daniel J; Sarafianos, Stefan G; Wang, Zhengqiang

2017-12-01

Human immunodeficiency virus (HIV) reverse transcriptase (RT) associated ribonuclease H (RNase H) is the only HIV enzymatic function not targeted by current antiviral drugs. Although various chemotypes have been reported to inhibit HIV RNase H, few have shown significant antiviral activities. We report herein the design, synthesis and biological evaluation of a novel N-hydroxy thienopyrimidine-2,3-dione chemotype (11) which potently and selectively inhibited RNase H with considerable potency against HIV-1 in cell culture. Current structure-activity-relationship (SAR) identified analogue 11d as a nanomolar inhibitor of RNase H (IC 50  = 0.04 μM) with decent antiviral potency (EC 50  = 7.4 μM) and no cytotoxicity (CC 50  > 100 μM). In extended biochemical assays compound 11d did not inhibit RT polymerase (pol) while inhibiting integrase strand transfer (INST) with 53 fold lower potency (IC 50  = 2.1 μM) than RNase H inhibition. Crystallographic and molecular modeling studies confirmed the RNase H active site binding mode. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Enzyme Hydrolysates from Stichopus horrens as a New Source for Angiotensin-Converting Enzyme Inhibitory Peptides

PubMed Central

Forghani, Bita; Ebrahimpour, Afshin; Bakar, Jamilah; Abdul Hamid, Azizah; Hassan, Zaiton; Saari, Nazamid

2012-01-01

Stichopus horrens flesh was explored as a potential source for generating peptides with angiotensin-converting enzyme (ACE) inhibitory capacity using 6 proteases, namely alcalase, flavourzyme, trypsin, papain, bromelain, and protamex. Degree of hydrolysis (DH) and peptide profiling (SDS-PAGE) of Stichopus horrens hydrolysates (SHHs) was also assessed. Alcalase hydrolysate showed the highest DH value (39.8%) followed by flavourzyme hydrolysate (32.7%). Overall, alcalase hydrolysate exhibited the highest ACE inhibitory activity (IC50 value of 0.41 mg/mL) followed by flavourzyme hydrolysate (IC50 value of 2.24 mg/mL), trypsin hydrolysate (IC50 value of 2.28 mg/mL), papain hydrolysate (IC50 value of 2.48 mg/mL), bromelain hydrolysate (IC50 value of 4.21 mg/mL), and protamex hydrolysate (IC50 value of 6.38 mg/mL). The SDS-PAGE results showed that alcalase hydrolysate represented a unique pattern compared to others, which yielded potent ACE inhibitory peptides with molecular weight distribution lower than 20 kDa. The evaluation of the relationship between DH and IC50 values of alcalase and flavourzyme hydrolysates revealed that the trend between those parameters was related to the type of the protease used. We concluded that the tested SHHs would be used as a potential source of functional ACE inhibitory peptides for physiological benefits. PMID:22927875

Enzyme Hydrolysates from Stichopus horrens as a New Source for Angiotensin-Converting Enzyme Inhibitory Peptides.

PubMed

Forghani, Bita; Ebrahimpour, Afshin; Bakar, Jamilah; Abdul Hamid, Azizah; Hassan, Zaiton; Saari, Nazamid

2012-01-01

Stichopus horrens flesh was explored as a potential source for generating peptides with angiotensin-converting enzyme (ACE) inhibitory capacity using 6 proteases, namely alcalase, flavourzyme, trypsin, papain, bromelain, and protamex. Degree of hydrolysis (DH) and peptide profiling (SDS-PAGE) of Stichopus horrens hydrolysates (SHHs) was also assessed. Alcalase hydrolysate showed the highest DH value (39.8%) followed by flavourzyme hydrolysate (32.7%). Overall, alcalase hydrolysate exhibited the highest ACE inhibitory activity (IC(50) value of 0.41 mg/mL) followed by flavourzyme hydrolysate (IC(50) value of 2.24 mg/mL), trypsin hydrolysate (IC(50) value of 2.28 mg/mL), papain hydrolysate (IC(50) value of 2.48 mg/mL), bromelain hydrolysate (IC(50) value of 4.21 mg/mL), and protamex hydrolysate (IC(50) value of 6.38 mg/mL). The SDS-PAGE results showed that alcalase hydrolysate represented a unique pattern compared to others, which yielded potent ACE inhibitory peptides with molecular weight distribution lower than 20 kDa. The evaluation of the relationship between DH and IC(50) values of alcalase and flavourzyme hydrolysates revealed that the trend between those parameters was related to the type of the protease used. We concluded that the tested SHHs would be used as a potential source of functional ACE inhibitory peptides for physiological benefits.

2 H-1,2,3-Triazole-Based Dipeptidyl Nitriles: Potent, Selective, and Trypanocidal Rhodesain Inhibitors by Structure-Based Design.

PubMed

Giroud, Maude; Kuhn, Bernd; Saint-Auret, Sarah; Kuratli, Christoph; Martin, Rainer E; Schuler, Franz; Diederich, François; Kaiser, Marcel; Brun, Reto; Schirmeister, Tanja; Haap, Wolfgang

2018-04-26

Macrocyclic inhibitors of rhodesain (RD), a parasitic cysteine protease and drug target for the treatment of human African trypanosomiasis, have shown low metabolic stability at the macrocyclic ether bridge. A series of acyclic dipeptidyl nitriles was developed using structure-based design (PDB ID: 6EX8 ). The selectivity against the closely related cysteine protease human cathepsin L (hCatL) was substantially improved, up to 507-fold. In the S2 pocket, 3,4-dichlorophenylalanine residues provided high trypanocidal activities. In the S3 pocket, aromatic residues provided enhanced selectivity against hCatL. RD inhibition ( K i values) and in vitro cell-growth of Trypanosoma brucei rhodesiense (IC 50 values) were measured in the nanomolar range. Triazole-based ligands, obtained by a safe, gram-scale flow production of ethyl 1 H-1,2,3-triazole-4-carboxylate, showed excellent metabolic stability in human liver microsomes and in vivo half-lives of up to 1.53 h in mice. When orally administered to infected mice, parasitaemia was reduced but without complete removal of the parasites.

Evaluation of in vitro aldose reductase inhibitory potential of alkaloidal fractions of Piper nigrum, Murraya koenigii, Argemone mexicana, and Nelumbo nucifera.

PubMed

Gupta, Sakshi; Singh, Nirmal; Jaggi, Amteshwar Singh

2014-05-01

Aldose reductase is primarily involved in development of long-term diabetic complications due to increased polyol pathway activity. The synthetic aldose reductase inhibitors are not very successful clinically. Therefore, the natural sources may be exploited for safer and effective aldose reductase inhibitors. In the present study, the aldose reductase inhibitory potential of hydroalcoholic and alkaloidal extracts of Piper nigrum, Murraya koenigii, Argemone mexicana, and Nelumbo nucifera was evaluated. The hydroalcoholic and alkaloidal extracts of the selected plants were prepared. The different concentrations of hydroalcoholic and alkaloidal extracts of these plants were evaluated for their goat lens aldose reductase inhibitory activity using dl-glyceraldehyde as substrate. The aldose reductase inhibitory potential of extracts was assessed in terms of their IC50 value. Amongst the hydroalcoholic extracts, the highest aldose reductase inhibitory activity was shown by P. nigrum (IC50 value 35.64±2.7 μg/mL) followed by M. koenigii (IC50 value 45.67±2.57 μg/mL), A. mexicana (IC50 value 56.66±1.30 μg/mL), and N. nucifera (IC50 value 59.78±1.32 μg/mL). Among the alkaloidal extracts, highest inhibitory activity was shown by A. mexicana (IC50 value 25.67±1.25 μg/mL), followed by N. nucifera (IC50 value 28.82±1.85 μg/mL), P. nigrum (IC50 value 30.21±1.63 μg/mL), and M. koenigii (IC50 value 35.66±1.64 μg/mL). It may be concluded that the alkaloidal extracts of these plants possess potent aldose reductase inhibitory activity and may be therapeutically exploited in diabetes-related complications associated with increased activity of aldose reductase.

Synthesis and evaluation of 7-substituted coumarin derivatives as multimodal monoamine oxidase-B and cholinesterase inhibitors for the treatment of Alzheimer's disease.

PubMed

Joubert, Jacques; Foka, Germaine B; Repsold, Benjamin P; Oliver, Douglas W; Kapp, Erika; Malan, Sarel F

2017-01-05

A series of 7-substituted coumarin derivatives were designed and synthesised to display ChE and MAO-B inhibitory activity. The compounds consisted out of a coumarin structure (MAO-B inhibitor) and benzyl-, piperidine-, N-benzylpiperidine- or p-bromo-N-benzylpiperizine moiety, resembling the N-benzylpiperidine function of donepezil (ChE inhibitor), connected via an alkyl ether linkage at the 7 position. The biological assay results indicated that all the compounds (1-25) displayed selective inhibition to hMAO-B over hMAO-A, with the benzyloxy series (1-8, 10-13) showing nano-molar hMAO-B inhibition (IC 50 : 0.5-73 nM). Limited ChE inhibitory activity was however observed for the benzyloxy series with the exception of 2 and especially 3 showing selective BuChE inhibition. From this series 3 showed the best multifunctional activity (eqBuChE IC 50  = 0.96 μM, hMAO-A IC 50  = 2.13 μM, hMAO-B IC 50  = 0.0021 μM). Within the N-benzylpiperidine (16-19) and p-bromo-N-benzylpiperizine (21-24) series the compounds in general showed moderate ChE and MAO-B inhibitory activity. Of these compounds 19 was the most potent multifunctional agent showing good eeAChE and eqBuChE inhibition (IC 50  = 9.10 μM and 5.90 μM, respectively), and relatively potent and selective hMAO-B inhibition (IC 50  = 0.30 μM, SI = >33). Molecular modeling revealed that 19 was able to bind simultaneously to the CAS, mid-gorge and PAS sites of AChE and BuChE suggesting that it will be able to inhibit AChE induced Aβ aggregation. From this study, compounds that 3 and 19 can be considered as promising multifunctional lead compounds. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

ICECAP: an integrated, general-purpose, automation-assisted IC50/EC50 assay platform.

PubMed

Li, Ming; Chou, Judy; King, Kristopher W; Jing, Jing; Wei, Dong; Yang, Liyu

2015-02-01

IC50 and EC50 values are commonly used to evaluate drug potency. Mass spectrometry (MS)-centric bioanalytical and biomarker labs are now conducting IC50/EC50 assays, which, if done manually, are tedious and error-prone. Existing bioanalytical sample preparation automation systems cannot meet IC50/EC50 assay throughput demand. A general-purpose, automation-assisted IC50/EC50 assay platform was developed to automate the calculations of spiking solutions and the matrix solutions preparation scheme, the actual spiking and matrix solutions preparations, as well as the flexible sample extraction procedures after incubation. In addition, the platform also automates the data extraction, nonlinear regression curve fitting, computation of IC50/EC50 values, graphing, and reporting. The automation-assisted IC50/EC50 assay platform can process the whole class of assays of varying assay conditions. In each run, the system can handle up to 32 compounds and up to 10 concentration levels per compound, and it greatly improves IC50/EC50 assay experimental productivity and data processing efficiency. © 2014 Society for Laboratory Automation and Screening.

Multitarget Therapeutic Leads for Alzheimer's Disease: Quinolizidinyl Derivatives of Bi- and Tricyclic Systems as Dual Inhibitors of Cholinesterases and β-Amyloid (Aβ) Aggregation.

PubMed

Tonelli, Michele; Catto, Marco; Tasso, Bruno; Novelli, Federica; Canu, Caterina; Iusco, Giovanna; Pisani, Leonardo; Stradis, Angelo De; Denora, Nunzio; Sparatore, Anna; Boido, Vito; Carotti, Angelo; Sparatore, Fabio

2015-06-01

Multitarget therapeutic leads for Alzheimer's disease were designed on the models of compounds capable of maintaining or restoring cell protein homeostasis and of inhibiting β-amyloid (Aβ) oligomerization. Thirty-seven thioxanthen-9-one, xanthen-9-one, naphto- and anthraquinone derivatives were tested for the direct inhibition of Aβ(1-40) aggregation and for the inhibition of electric eel acetylcholinesterase (eeAChE) and horse serum butyrylcholinesterase (hsBChE). These compounds are characterized by basic side chains, mainly quinolizidinylalkyl moieties, linked to various bi- and tri-cyclic (hetero)aromatic systems. With very few exceptions, these compounds displayed inhibitory activity on both AChE and BChE and on the spontaneous aggregation of β-amyloid. In most cases, IC50 values were in the low micromolar and sub-micromolar range, but some compounds even reached nanomolar potency. The time course of amyloid aggregation in the presence of the most active derivative (IC50 =0.84 μM) revealed that these compounds might act as destabilizers of mature fibrils rather than mere inhibitors of fibrillization. Many compounds inhibited one or both cholinesterases and Aβ aggregation with similar potency, a fundamental requisite for the possible development of therapeutics exhibiting a multitarget mechanism of action. The described compounds thus represent interesting leads for the development of multitarget AD therapeutics. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis, in vitro and in vivo giardicidal activity of nitrothiazole-NSAID chimeras displaying broad antiprotozoal spectrum.

PubMed

Colín-Lozano, Blanca; León-Rivera, Ismael; Chan-Bacab, Manuel Jesús; Ortega-Morales, Benjamín Otto; Moo-Puc, Rosa; López-Guerrero, Vanessa; Hernández-Núñez, Emanuel; Argüello-Garcia, Raúl; Scior, Thomas; Barbosa-Cabrera, Elizabeth; Navarrete-Vázquez, Gabriel

2017-08-01

We designed and synthesized five new 5-nitrothiazole-NSAID chimeras as analogues of nitazoxanide, using a DCC-activated amidation. Compounds 1-5 were tested in vitro against a panel of five protozoa: 2 amitochondriates (Giardia intestinalis, Trichomonas vaginalis) and 3 kinetoplastids (Leishmania mexicana, Leishmania amazonensis and Trypanosoma cruzi). All chimeras showed broad spectrum and potent antiprotozoal activities, with IC 50 values ranging from the low micromolar to nanomolar order. Compounds 1-5 were even more active than metronidazole and nitazoxanide, two marketed first-line drugs against giardiasis. In particular, compound 4 (an indomethacin hybrid) was one of the most potent of the series, inhibiting G. intestinalis growth in vitro with an IC 50 of 0.145μM. Compound 4 was 38-times more potent than metronidazole and 8-times more active than nitazoxanide. The in vivo giardicidal effect of 4 was evaluated in a CD-1 mouse model obtaining a median effective dose of 1.709μg/kg (3.53nmol/kg), a 321-fold and 1015-fold increase in effectiveness after intragastric administration over metronidazole and nitazoxanide, respectively. Compounds 1 and 3 (hybrids of ibuprofen and clofibric acid), showed potent giardicidal activities in the in vitro as well as in the in vivo assays after oral administration. Therefore, compounds 1-5 constitute promising drug candidates for further testing in experimental chemotherapy against giardiasis, trichomoniasis, leishmaniasis and even trypanosomiasis infections. Copyright © 2017 Elsevier Ltd. All rights reserved.

Interrogating alkyl and arylalkylpolyamino (bis)urea and (bis)thiourea isosteres as potent antimalarial chemotypes against multiple lifecycle forms of Plasmodium falciparum parasites.

PubMed

Verlinden, Bianca K; de Beer, Marna; Pachaiyappan, Boobalan; Besaans, Ethan; Andayi, Warren A; Reader, Janette; Niemand, Jandeli; van Biljon, Riette; Guy, Kiplin; Egan, Timothy; Woster, Patrick M; Birkholtz, Lyn-Marie

2015-08-15

A new series of potent potent aryl/alkylated (bis)urea- and (bis)thiourea polyamine analogues were synthesized and evaluated in vitro for their antiplasmodial activity. Altering the carbon backbone and terminal substituents increased the potency of analogues in the compound library 3-fold, with the most active compounds, 15 and 16, showing half-maximal inhibitory concentrations (IC50 values) of 28 and 30 nM, respectively, against various Plasmodium falciparum parasite strains without any cross-resistance. In vitro evaluation of the cytotoxicity of these analogues revealed marked selectivity towards targeting malaria parasites compared to mammalian HepG2 cells (>5000-fold lower IC50 against the parasite). Preliminary biological evaluation of the polyamine analogue antiplasmodial phenotype revealed that (bis)urea compounds target parasite asexual proliferation, whereas (bis)thiourea compounds of the same series have the unique ability to block transmissible gametocyte forms of the parasite, indicating pluripharmacology against proliferative and non-proliferative forms of the parasite. In this manuscript, we describe these results and postulate a refined structure-activity relationship (SAR) model for antiplasmodial polyamine analogues. The terminally aryl/alkylated (bis)urea- and (bis)thiourea-polyamine analogues featuring a 3-5-3 or 3-6-3 carbon backbone represent a structurally novel and distinct class of potential antiplasmodials with activities in the low nanomolar range, and high selectivity against various lifecycle forms of P. falciparum parasites. Copyright © 2015 Elsevier Ltd. All rights reserved.

2,4,6-Trichlorophenylhydrazine Schiff bases as DPPH radical and super oxide anion scavengers.

PubMed

Khan, Khalid Mohammed; Shah, Zarbad; Ahmad, Viqar Uddin; Khan, Momin; Taha, Muhammad; Rahim, Fazal; Ali, Sajjad; Ambreen, Nida; Perveen, Shahnaz; Choudhary, M Iqbal; Voelter, Wolfgang

2012-05-01

Syntheses of thirty 2,4,6-trichlorophenylhydrazine Schiff bases 1-30 were carried out and evaluated for their in vitro DPPH radical and super oxide anion scavenging activities. Compounds 1-30 have shown a varying degree of DPPH radical scavenging activity and their IC50 values range between 4.05-369.30 µM. The compounds 17, 28, 18, 14, 8, 15, 12, 2, 29, and 7 exhibited IC50 values ranging between 4.05±0.06-24.42±0.86 µM which are superior to standard n-propylgallate (IC50=30.12±0.27 µM). Selected compounds have shown a varying degree of superoxide anion radical scavenger activity and their IC50 values range between 91.23-406.90 µM. The compounds 28, 8, 17, 15, and 14, showed IC50 values between 91.23±1.2-105.31±2.29 µM which are superior to standard n-propylgallate (IC50=106.34±1.6 µM).

Variability in P-Glycoprotein Inhibitory Potency (IC50) Using Various in Vitro Experimental Systems: Implications for Universal Digoxin Drug-Drug Interaction Risk Assessment Decision Criteria

PubMed Central

Bentz, Joe; O’Connor, Michael P.; Bednarczyk, Dallas; Coleman, JoAnn; Lee, Caroline; Palm, Johan; Pak, Y. Anne; Perloff, Elke S.; Reyner, Eric; Balimane, Praveen; Brännström, Marie; Chu, Xiaoyan; Funk, Christoph; Guo, Ailan; Hanna, Imad; Herédi-Szabó, Krisztina; Hillgren, Kate; Li, Libin; Hollnack-Pusch, Evelyn; Jamei, Masoud; Lin, Xuena; Mason, Andrew K.; Neuhoff, Sibylle; Patel, Aarti; Podila, Lalitha; Plise, Emile; Rajaraman, Ganesh; Salphati, Laurent; Sands, Eric; Taub, Mitchell E.; Taur, Jan-Shiang; Weitz, Dietmar; Wortelboer, Heleen M.; Xia, Cindy Q.; Xiao, Guangqing; Yabut, Jocelyn; Yamagata, Tetsuo; Zhang, Lei

2013-01-01

A P-glycoprotein (P-gp) IC50 working group was established with 23 participating pharmaceutical and contract research laboratories and one academic institution to assess interlaboratory variability in P-gp IC50 determinations. Each laboratory followed its in-house protocol to determine in vitro IC50 values for 16 inhibitors using four different test systems: human colon adenocarcinoma cells (Caco-2; eleven laboratories), Madin-Darby canine kidney cells transfected with MDR1 cDNA (MDCKII-MDR1; six laboratories), and Lilly Laboratories Cells—Porcine Kidney Nr. 1 cells transfected with MDR1 cDNA (LLC-PK1-MDR1; four laboratories), and membrane vesicles containing human P-glycoprotein (P-gp; five laboratories). For cell models, various equations to calculate remaining transport activity (e.g., efflux ratio, unidirectional flux, net-secretory-flux) were also evaluated. The difference in IC50 values for each of the inhibitors across all test systems and equations ranged from a minimum of 20- and 24-fold between lowest and highest IC50 values for sertraline and isradipine, to a maximum of 407- and 796-fold for telmisartan and verapamil, respectively. For telmisartan and verapamil, variability was greatly influenced by data from one laboratory in each case. Excluding these two data sets brings the range in IC50 values for telmisartan and verapamil down to 69- and 159-fold. The efflux ratio-based equation generally resulted in severalfold lower IC50 values compared with unidirectional or net-secretory-flux equations. Statistical analysis indicated that variability in IC50 values was mainly due to interlaboratory variability, rather than an implicit systematic difference between test systems. Potential reasons for variability are discussed and the simplest, most robust experimental design for P-gp IC50 determination proposed. The impact of these findings on drug-drug interaction risk assessment is discussed in the companion article (Ellens et al., 2013) and recommendations are provided. PMID:23620485

A CD13-targeting peptide integrated protein inhibits human liver cancer growth by killing cancer stem cells and suppressing angiogenesis.

PubMed

Zheng, Yan-Bo; Gong, Jian-Hua; Liu, Xiu-Jun; Li, Yi; Zhen, Yong-Su

2017-05-01

CD13 is a marker of angiogenic endothelial cells, and recently it is proved to be a biomarker of human liver cancer stem cells (CSCs). Herein, the therapeutic effects of NGR-LDP-AE, a fusion protein composed of CD13-targeting peptide NGR and antitumor antibiotic lidamycin, on human liver cancer and its mechanism were studied. Western blot and immunofluorescence assay demonstrated that CD13 (WM15 epitope) was expressed in both human liver cancer cell lines and vascular endothelial cells, while absent in normal liver cells. MTT assay showed that NGR-LDP-AE displayed potent cytotoxicity to cultured tumor cell lines with IC 50 values at low nanomolar level. NGR-LDP-AE inhibited tumorsphere formation of liver cancer cells, and the IC 50 values were much lower than that in MTT assay, indicating selectively killing of CSCs. In endothelial tube formation assay, NGR-LDP-AE at low cytotoxic dose significantly inhibited the formation of intact tube networks. Animal experiment demonstrated that NGR-LDP-AE inhibited the growth of human liver cancer xenograft. Immunohistochemical analysis showed that NGR-LDP-AE induced the down-regulation of CD13. In vitro experiment using cultured tumor cells also confirmed this result. NGR-LDP-AE activated both apoptotic and autophagic pathways in cultured tumor cells, while the induced autophagy protected cells from death. Conclusively, NGR-LDP-AE exerts its antitumor activity via killing liver CSCs and inhibiting angiogenesis. With one targeting motif, NGR-LDP-AE acts on both liver CSCs and angiogenic endothelial cells. It is a promising dual targeting fusion protein for liver cancer therapy, especially for advanced or relapsed cancers. © 2017 Wiley Periodicals, Inc.

Lipophilicity plays a major role in modulating the inhibition of monoamine oxidase B by 7-substituted coumarins.

PubMed

Carotti, Angelo; Altomare, Cosimo; Catto, Marco; Gnerre, Carmela; Summo, Luciana; De Marco, Agostino; Rose, Sarah; Jenner, Peter; Testa, Bernard

2006-02-01

A series of coumarin derivatives (1-22), bearing at the 7-position ether, ketone, ester, carbamate, or amide functions of varying size and lipophilicity, were synthesized and investigated for their in vitro monoamine oxidase-A and -B (MAO-A and -B) inhibitory activities. Most of the compounds acted preferentially as MAO-B inhibitors, with IC(50) values in the micromolar to low-nanomolar range. A structure-activity-relationship (SAR) study highlighted lipophilicity as an important property modulating the MAO-B inhibition potency of 7-substituted coumarins, as shown by a linear correlation (n=20, r(2)=0.72) between pIC(50) and calculated log P values. The stability of ester-containing coumarin derivatives in rat plasma provided information on factors that either favor (lipophilicity) or decrease (steric hindrance) esterase-catalyzed hydrolysis. Two compounds (14 and 22) were selected to investigate how lipophilicity and enzymatic stability may affect in vivo MAO activities, as assayed ex vivo in rat. The most-potent and -selective MAO-B inhibitor 22 (=7-[(3,4-difluorobenzyl)oxy]-3,4-dimethyl-1-benzopyran-2(2H)-one) within the examined series significantly inhibited (>60%) ex vivo rat-liver and striatal MAO-B activities 1 h after intraperitoneal administration of high doses (100 and 300 mumol kg(-1)), revealing its ability to cross the blood-brain barrier. At the same doses, liver and striatum MAO-A was less inhibited in vivo, somehow reflecting MAO-B selectivity, as assessed in vitro. In contrast, the metabolically less stable derivative 14, bearing an isopropyl ester in the lateral chain, had a weak effect on hepatic MAO-B activity in vivo, and none on striatal MAO-B, but, surprisingly, displayed inhibitory effects on MAO-A in both peripheral and brain tissues.

Antiplasmodial dihetarylthioethers target the coenzyme A synthesis pathway in Plasmodium falciparum erythrocytic stages.

PubMed

Weidner, Thomas; Lucantoni, Leonardo; Nasereddin, Abed; Preu, Lutz; Jones, Peter G; Dzikowski, Ron; Avery, Vicky M; Kunick, Conrad

2017-05-15

Malaria is a widespread infectious disease that threatens a large proportion of the population in tropical and subtropical areas. Given the emerging resistance against the current standard anti-malaria chemotherapeutics, the development of alternative drugs is urgently needed. New anti-malarials representing chemotypes unrelated to currently used drugs have an increased potential for displaying novel mechanisms of action and thus exhibit low risk of cross-resistance against established drugs. Phenotypic screening of a small library (32 kinase-inhibitor analogs) against Plasmodium falciparum NF54-luc asexual erythrocytic stage parasites identified a diarylthioether structurally unrelated to registered drugs. Hit expansion led to a series in which the most potent congener displayed nanomolar antiparasitic activity (IC 50  = 39 nM, 3D7 strain). Structure-activity relationship analysis revealed a thieno[2,3-d]pyrimidine on one side of the thioether linkage as a prerequisite for antiplasmodial activity. Within the series, the oxazole derivative KuWei173 showed high potency (IC 50  = 75 nM; 3D7 strain), good solubility in aqueous solvents (1.33 mM), and >100-fold selectivity toward human cell lines. Rescue experiments identified inhibition of the plasmodial coenzyme A synthesis as a possible mode of action for this compound class. The class of antiplasmodial bishetarylthioethers reported here has been shown to interfere with plasmodial coenzyme A synthesis, a mechanism of action not yet exploited for registered anti-malarial drugs. The oxazole congener KuWei173 displays double-digit nanomolar antiplasmodial activity, selectivity against human cell lines, high drug likeness, and thus represents a promising chemical starting point for further drug development.

Fragment-based drug design and identification of HJC0123, a novel orally bioavailable STAT3 inhibitor for cancer therapy

PubMed Central

Chen, Haijun; Yang, Zhengduo; Ding, Chunyong; Chu, Lili; Zhang, Yusong; Terry, Kristin; Liu, Huiling; Shen, Qiang; Zhou, Jia

2013-01-01

Fragment-based drug design (FBDD) is a promising approach for the generation of lead molecules with enhanced activity and especially drug-like properties against therapeutic targets. Herein, we report the fragment-based drug design, systematic chemical synthesis and pharmacological evaluation of novel scaffolds as potent anticancer agents by utilizing six privileged fragments from known STAT3 inhibitors. Several new molecules such as compounds 5, 12, and 19 that may act as advanced chemical leads have been identified. The most potent compound 5 (HJC0123) has demonstrated to inhibit STAT3 promoter activity, downregulate phosphorylation of STAT3, increase the expression of cleaved caspase-3, inhibit cell cycle progression and promote apoptosis in breast and pancreatic cancer cells with low micromolar to nanomolar IC50 values. Furthermore, compound 5 significantly suppressed estrogen receptor (ER)-negative breast cancer MDA-MB-231 xenograft tumor growth in vivo (p.o.), indicating its great potential as an efficacious and orally bioavailable drug candidate for human cancer therapy. PMID:23416191

Structure-based design and biological evaluation of novel 2-(indol-2-yl) thiazole derivatives as xanthine oxidase inhibitors.

PubMed

Song, Jeong Uk; Jang, Jae Wan; Kim, Tae Hun; Park, Heuisul; Park, Wan Su; Jung, Sang-Hun; Kim, Geun Tae

2016-02-01

Inhibition of xanthine oxidase (XO) has obviously been a central concept for controlling hyperuricemia, which causes serious and painful inflammatory arthritis disease such as gout. We discovered a series of novel 2-(indol-2-yl)thiazole derivatives as XO inhibitors at the level of nanomolar activity. Structure-guided design using molecular modeling program (Accelrys Software program) provided an excellent basis for optimization of 2-(indol-2-yl)thiazole compounds. Structure-activity relationship indicated that hydrophobic alkoxy group (isopropoxy, cyclopentoxy) at 5-position and hydrogen binding acceptor (NO2, CN) at 7-position of indole ring appear as critical functional groups. Among the compounds, 2-(7-nitro-5-isopropoxy-indol-2-yl)-4-methylthiazole-5-carboxylic acid (9m) exhibits the most potent XO inhibitory activity (IC50 value: 5.1 nM) and the excellent uric acid lowering activity in potassium oxonate induced hyperuricemic rat model. Copyright © 2016. Published by Elsevier Ltd.

Synthesis and evaluation of novel multimeric neurotensin(8-13) analogs.

PubMed

Hultsch, Christina; Pawelke, Beate; Bergmann, Ralf; Wuest, Frank

2006-09-01

Neurotensin(8-13) is a hexapeptide with subnanomolar affinity to the neurotensin receptor 1 which is expressed with high incidence in several human tumor entities. Thus, radiolabeled neurotensin(8-13) might be used for tumor targeting. However, its application is limited by insufficient metabolic stability. The present study aims at improving metabolic stability by the synthesis of multimeric neurotensin(8-13) derivatives rather than commonly employed chemical modifications of the peptide itself. Thus, different dimeric and tetrameric peptides carrying C- or N-terminal attached neurotensin(8-13) moieties have been synthesized and their binding affinity toward the neurotensin receptor has been determined. The results demonstrate that branched compounds containing neurotensin(8-13) attached via its C-terminus only show low receptor affinities, whilst derivatives with neurotensin(8-13) attached via the N-terminus show IC50 values in the nanomolar range. Moreover, within the multimeric neurotensin(8-13) derivatives with neurotensin(8-13) attached via the N-terminus an increasing number of branching units lead to higher binding affinities toward the neurotensin receptor.

Screening of synthetic phage display scFv libraries yields competitive ligands of human leptin receptor.

PubMed

Molek, Peter; Vodnik, Miha; Strukelj, Borut; Bratkovič, Tomaž

2014-09-26

Initially considered the main endogenous anorexigenic factor, fat-derived leptin turned out to be a markedly pleiotropic hormone, influencing diverse physiological processes. Moreover, hyperleptinemia in obese individuals has been linked to the onset or progression of serious disorders, such as cancer, autoimmune diseases, and atherosclerosis, and antagonizing peripheral leptin's signalization has been shown to improve these conditions. To develop an antibody-based leptin antagonist we have devised a tailored panning procedure and screened two phage display libraries of single chain variable antibody fragments (scFvs) against recombinant leptin receptor. One of the scFvs was expressed in Escherichia coli and its interaction with leptin receptor was characterized in more detail. It was found to recognize a discontinuous epitope and to compete with leptin for receptor binding with IC50 and Kd values in the nanomolar range. The reported scFv represents a lead for development of leptin antagonists that may ultimately find use in therapy of various hyperleptinemia-related disorders. Copyright © 2014 Elsevier Inc. All rights reserved.

On the discovery of new potent human farnesyltransferase inhibitors: emerging pyroglutamic derivatives.

PubMed

Homerin, Germain; Lipka, Emmanuelle; Rigo, Benoît; Farce, Amaury; Dubois, Joëlle; Ghinet, Alina

2017-10-04

In the current context of lack of emergence of innovative human farnesyltransferase inhibitors families, and given all new therapeutic perspectives that open up for such molecules in rare diseases (e.g. Hutchinson-Gilford progeria syndrome), and in delta hepatitis, cardiovascular or neuroinflammatory diseases, we have just discovered a new series of powerful inhibitors. These molecules are pyroglutamic acid derivatives, and were evaluated on human farnesyltransferase in vitro then modeled in silico on the active site of the protein. Three main points of the pyroglutamic acid cycle have undergone chemical modulations pyroglutamides in position 5 (compounds 7a-h), constrained bicyclic analogues of pyrroloimidazoledione type (compounds 1a-h), modulation of the position 3 (compounds 2-5 and 8), and allowed the first SAR in the field. Five derivatives in the current work have IC 50 values in the small nanomolar range (2-5 nM). These new lead compounds open the way for the next generation of farnesyltransferase inhibitors.

Exploration of acetanilide derivatives of 1-(ω-phenoxyalkyl)uracils as novel inhibitors of Hepatitis C Virus replication

PubMed Central

Magri, Andrea; Ozerov, Alexander A.; Tunitskaya, Vera L.; Valuev-Elliston, Vladimir T.; Wahid, Ahmed; Pirisi, Mario; Simmonds, Peter; Ivanov, Alexander V.; Novikov, Mikhail S.; Patel, Arvind H.

2016-01-01

Hepatitis C Virus (HCV) is a major public health problem worldwide. While highly efficacious directly-acting antiviral agents have been developed in recent years, their high costs and relative inaccessibility make their use limited. Here, we describe new 1-(ω-phenoxyalkyl)uracils bearing acetanilide fragment in 3 position of pyrimidine ring as potential antiviral drugs against HCV. Using a combination of various biochemical assays and in vitro virus infection and replication models, we show that our compounds are able to significantly reduce viral genomic replication, independently of virus genotype, with their IC50 values in the nanomolar range. We also demonstrate that our compounds can block de novo RNA synthesis and that effect is dependent on a chemical structure of the compounds. A detailed structure-activity relationship revealed that the most active compounds were the N3-substituted uracil derivatives containing 6-(4-bromophenoxy)hexyl or 8-(4-bromophenoxy)octyl fragment at N1 position. PMID:27406141

Exploration of acetanilide derivatives of 1-(ω-phenoxyalkyl)uracils as novel inhibitors of Hepatitis C Virus replication.

PubMed

Magri, Andrea; Ozerov, Alexander A; Tunitskaya, Vera L; Valuev-Elliston, Vladimir T; Wahid, Ahmed; Pirisi, Mario; Simmonds, Peter; Ivanov, Alexander V; Novikov, Mikhail S; Patel, Arvind H

2016-07-12

Hepatitis C Virus (HCV) is a major public health problem worldwide. While highly efficacious directly-acting antiviral agents have been developed in recent years, their high costs and relative inaccessibility make their use limited. Here, we describe new 1-(ω-phenoxyalkyl)uracils bearing acetanilide fragment in 3 position of pyrimidine ring as potential antiviral drugs against HCV. Using a combination of various biochemical assays and in vitro virus infection and replication models, we show that our compounds are able to significantly reduce viral genomic replication, independently of virus genotype, with their IC50 values in the nanomolar range. We also demonstrate that our compounds can block de novo RNA synthesis and that effect is dependent on a chemical structure of the compounds. A detailed structure-activity relationship revealed that the most active compounds were the N(3)-substituted uracil derivatives containing 6-(4-bromophenoxy)hexyl or 8-(4-bromophenoxy)octyl fragment at N(1) position.

Synthesis and characterization of a small analogue of the anticancer natural product leinamycin.

PubMed

Keerthi, Kripa; Rajapakse, Anuruddha; Sun, Daekyu; Gates, Kent S

2013-01-01

Leinamycin (1) is a Streptomyces-derived natural product that displays nanomolar IC(50) values against human cancer cell lines. In the work described here, we report the synthesis and characterization of a small leinamycin analogue 19 that closely resembles the 'upper-right quadrant' of the natural product, consisting of an alicyclic 1,2-dithiolan-3-one 1-oxide heterocycle connected to an alkene by a two-carbon linker. The results indicate that this small analogue contains the core set of functional groups required to enable thiol-triggered generation of both redox active polysulfides and an episulfonium ion intermediate via the complex reaction cascade first seen in the natural product leinamycin. The small leinamycin analogue 19 caused thiol-triggered oxidative DNA strand cleavage in a manner similar to the natural product, but did not alkyate duplex DNA effectively. This highlights the central role of the 18-membered macrocycle of leinamycin in driving efficient DNA alkylation by the natural product. Copyright © 2012 Elsevier Ltd. All rights reserved.

Polymeric mannosides prevent DC-SIGN-mediated cell-infection by cytomegalovirus.

PubMed

Brument, S; Cheneau, C; Brissonnet, Y; Deniaud, D; Halary, F; Gouin, S G

2017-09-20

Human cytomegalovirus (HCMV) is a beta-herpesvirus with a high prevalence in the population. HCMV is asymptomatic for immunocompetent adults but is a leading cause of morbidity for new born and immunocompromised patients. It was recently shown that the envelope glycoprotein B (gB) of HCMV interacts with the Dendritic Cell-Specific ICAM-3 Grabbing Non integrin (DC-SIGN) to infect the host. In this work we developed a set of DC-SIGN blockers based on mono-, di-, tetra and polyvalent mannosides. The multivalent mannosides were designed to interact with the carbohydrate recognition domains of DC-SIGN in a chelate or bind and recapture process, and represent the first chemical antiadhesives of HCMV reported so far. Polymeric dextrans coated with triazolylheptylmannoside (THM) ligands were highly potent, blocking the gB and DC-SIGN interaction at nanomolar concentrations. The compounds were further assessed for their ability to prevent the DC-SIGN mediated HCMV infection of dendritic cells. A dextran polymer coated with an average of 902 THM ligands showed an outstanding effect in blocking the HCMV trans-infection with IC 50 values down to the picomolar range (nanomolar when expressed in THM concentration). Each THM moiety on the polymer surpassed the antiadhesive effect of the methylmannoside reference by more than four orders of magnitude. The compound proved non-cytotoxic at the high concentration of 2 mM and therefore represents an interesting antiadhesive candidate against HCMV and potentially against other virus hijacking dendritic cells to infect the host.

In Vitro Activities of ER-119884 and E5700, Two Potent Squalene Synthase Inhibitors, against Leishmania amazonensis: Antiproliferative, Biochemical, and Ultrastructural Effects▿

PubMed Central

Fernandes Rodrigues, Juliany Cola; Concepcion, Juan Luis; Rodrigues, Carlos; Caldera, Aura; Urbina, Julio A.; de Souza, Wanderley

2008-01-01

ER-119884 and E5700, novel arylquinuclidine derivatives developed as cholesterol-lowering agents, were potent in vitro growth inhibitors of both proliferative stages of Leishmania amazonensis, the main causative agent of cutaneous leishmaniasis in South America, with the 50% inhibitory concentrations (IC50s) being in the low-nanomolar to subnanomolar range. The compounds were very potent noncompetitive inhibitors of native L. amazonensis squalene synthase (SQS), with inhibition constants also being in the nanomolar to subnanomolar range. Growth inhibition was strictly associated with the depletion of the parasite's main endogenous sterols and the concomitant accumulation of exogenous cholesterol. Using electron microscopy, we identified the intracellular structures affected by the compounds. A large number of lipid inclusions displaying different shapes and electron densities were observed after treatment with both SQS inhibitors, and these inclusions were associated with an intense disorganization of the membrane that surrounds the cell body and flagellum, as well as the endoplasmic reticulum and the Golgi complex. Cells treated with ER-119884 but not those treated with E5700 had an altered cytoskeleton organization due to an abnormal distribution of tubulin, and many were arrested at cytokinesis. A prominent contractile vacuole and a phenotype typical of programmed cell death were frequently found in drug-treated cells. The selectivity of the drugs was demonstrated with the JC-1 mitochondrial fluorescent label and by trypan blue exclusion tests with macrophages, which showed that the IC50s against the host cells were 4 to 5 orders of magnitude greater that those against the intracellular parasites. Taken together, our results show that ER-119884 and E5700 are unusually potent and selective inhibitors of the growth of Leishmania amazonensis, probably because of their inhibitory effects on de novo sterol biosynthesis at the level of SQS, but some of our observations indicate that ER-119884 may also interfere with other cellular processes. PMID:18765694

The 8-Pyrrole-Benzothiazinones Are Noncovalent Inhibitors of DprE1 from Mycobacterium tuberculosis

PubMed Central

Makarov, Vadim; Neres, João; Hartkoorn, Ruben C.; Ryabova, Olga B.; Kazakova, Elena; Šarkan, Michal; Huszár, Stanislav; Piton, Jérémie; Kolly, Gaëlle S.; Vocat, Anthony; Conroy, Trent M.; Mikušová, Katarína

2015-01-01

8-Nitro-benzothiazinones (BTZs), such as BTZ043 and PBTZ169, inhibit decaprenylphosphoryl-β-d-ribose 2′-oxidase (DprE1) and display nanomolar bactericidal activity against Mycobacterium tuberculosis in vitro. Structure-activity relationship (SAR) studies revealed the 8-nitro group of the BTZ scaffold to be crucial for the mechanism of action, which involves formation of a semimercaptal bond with Cys387 in the active site of DprE1. To date, substitution of the 8-nitro group has led to extensive loss of antimycobacterial activity. Here, we report the synthesis and characterization of the pyrrole-benzothiazinones PyrBTZ01 and PyrBTZ02, non-nitro-benzothiazinones that retain significant antimycobacterial activity, with MICs of 0.16 μg/ml against M. tuberculosis. These compounds inhibit DprE1 with 50% inhibitory concentration (IC50) values of <8 μM and present favorable in vitro absorption-distribution-metabolism-excretion/toxicity (ADME/T) and in vivo pharmacokinetic profiles. The most promising compound, PyrBTZ01, did not show efficacy in a mouse model of acute tuberculosis, suggesting that BTZ-mediated killing through DprE1 inhibition requires a combination of both covalent bond formation and compound potency. PMID:25987616

Bioactive components from the heartwood of Pterocarpus santalinus.

PubMed

Wu, Shou-Fang; Hwang, Tsong-Long; Chen, Shu-Li; Wu, Chin-Chung; Ohkoshi, Emika; Lee, Kuo-Hsiung; Chang, Fang-Rong; Wu, Yang-Chang

2011-09-15

One new phenanthrenedione, pterolinus K (1), and one new chalcone, pterolinus L (2) were isolated from the heartwood extract of Pterocarpus santalinus. The structures were elucidated by spectroscopic methods. Both 1 and 2 showed inhibitory effect on elastase release by human neutrophils in response to fMLP with an IC(50) value of 4.24 and 0.95 μM, and compound 1 also inhibited superoxide anion generation with IC(50) value of 0.99 μM. In addition, compound 1 showed selective cytotoxicity against HepG2 with IC(50) value of 10.86 μM, while compound 2 showed a moderate cytotoxicity against KB with IC(50) values of 17.18 μM. Copyright © 2011 Elsevier Ltd. All rights reserved.

Sirc-cvs cytotoxicity test: an alternative for predicting rodent acute systemic toxicity.

PubMed

Kitagaki, Masato; Wakuri, Shinobu; Hirota, Morihiko; Tanaka, Noriho; Itagaki, Hiroshi

2006-10-01

An in vitro crystal violet staining method using the rabbit cornea-derived cell line (SIRC-CVS) has been developed as an alternative to predict acute systemic toxicity in rodents. Seventy-nine chemicals, the in vitro cytotoxicity of which was already reported by the Multicenter Evaluation of In vitro Toxicity (MEIC) and ICCVAM/ECVAM, were selected as test compounds. The cells were incubated with the chemicals for 72 hrs and the IC(50) and IC(35) values (microg/mL) were obtained. The results were compared to the in vivo (rat or mouse) "most toxic" oral, intraperitoneal, subcutaneous and intravenous LD(50) values (mg/kg) taken from the RTECS database for each of the chemicals by using Pearson's correlation statistics. The following parameters were calculated: accuracy, sensitivity, specificity, prevalence, positive predictability, and negative predictability. Good linear correlations (Pearson's coefficient; r>0.6) were observed between either the IC(50) or the IC(35) values and all the LD(50) values. Among them, a statistically significant high correlation (r=0.8102, p<0.001) required for acute systemic toxicity prediction was obtained between the IC(50) values and the oral LD(50) values. By using the cut-off concentrations of 2,000 mg/kg (LD(50)) and 4,225 microg/mL (IC(50)), no false negatives were observed, and the accuracy was 84.8%. From this, it is concluded that this method could be used to predict the acute systemic toxicity potential of chemicals in rodents.

Inhibition of P-glycoprotein in Caco-2 cells: effects of herbal remedies frequently used by cancer patients.

PubMed

Engdal, S; Nilsen, O G

2008-06-01

1. The herbal products Natto K2, Agaricus, mistletoe, noni juice, green tea and garlic were investigated for in vitro inhibitory potential on P-glycoprotein (P-gp)-mediated transport of digoxin (30 nM) in differentiated and polarized Caco-2 cells. 2. Satisfactory cell functionality was demonstrated through measurements of assay linearity, transepithelial electric resistance (TEER), cytotoxicity, mannitol permeability, and inclusion of the positive inhibition control verapamil. 3. The most potent inhibitors of the net digoxin flux (IC(50)) were mistletoe > Natto K2 > Agaricus > green tea (0.022, 0.62, 3.81, >4.5 mg ml(-1), respectively). Mistletoe also showed the lowest IC(25) value, close to that obtained by verapamil (1.0 and 0.5 microg ml(-1), respectively). The IC(50)/IC(25) ratio was found to be a good parameter for the determination of inhibition profiles. Garlic and noni juice were classified as non-inhibitors. 4. This study shows that mistletoe, Natto K2, Agaricus and green tea inhibit P-gp in vitro. Special attention should be paid to mistletoe due to very low IC(50) and IC(25) values and to Natto K2 due to a low IC(50) value and a low IC(50)/IC(25) ratio.

Automation of flow injection gas diffusion-ion chromatography for the nanomolar determination of methylamines and ammonia in seawater and atmospheric samples

PubMed Central

Gibb, Stuart W.; Wood, John W.; Fauzi, R.; Mantoura, C.

1995-01-01

The automation and improved design and performance of Flow Injection Gas Diffusion-Ion Chromatography (FIGD-IC), a novel technique for the simultaneous analysis of trace ammonia (NH3) and methylamines (MAs) in aqueous media, is presented. Automated Flow Injection Gas Diffusion (FIGD) promotes the selective transmembrane diffusion of MAs and NH3 from aqueous sample under strongly alkaline (pH > 12, NaOH), chelated (EDTA) conditions into a recycled acidic acceptor stream. The acceptor is then injected onto an ion chromatograph where NH3 and the MAs are fully resolved as their cations and detected conductimetrically. A versatile PC interfaced control unit and data capture unit (DCU) are employed in series to direct the selonoid valve switching sequence, IC operation and collection of data. Automation, together with other modifications improved both linearily (R2 > 0.99 MAs 0-100 nM, NH3 0-1000 nM) and precision (<8%) of FIGD-IC at nanomolar concentrations, compared with the manual procedure. The system was successfully applied to the determination of MAs and NH3 in seawater and in trapped particulate and gaseous atmospheric samples during an oceanographic research cruise. PMID:18925047

Malaysian brown seaweeds Sargassum siliquosum and Sargassum polycystum: Low density lipoprotein (LDL) oxidation, angiotensin converting enzyme (ACE), α-amylase, and α-glucosidase inhibition activities.

PubMed

Nagappan, Hemlatha; Pee, Poh Ping; Kee, Sandra Hui Yin; Ow, Ji Tsong; Yan, See Wan; Chew, Lye Yee; Kong, Kin Weng

2017-09-01

Two Malaysian brown seaweeds, Sargassum siliquosum and Sargassum polycystum were first extracted using methanol to get the crude extract (CE) and further fractionated to obtain fucoxanthin-rich fraction (FRF). Samples were evaluated for their phenolic, flavonoid, and fucoxanthin contents, as well as their inhibitory activities towards low density lipoprotein (LDL) oxidation, angiotensin converting enzyme (ACE), α-amylase, and α-glucosidase. In LDL oxidation assay, an increasing trend in antioxidant activity was observed as the concentration of FRF (0.04-0.2mg/mL) and CE (0.2-1.0mg/mL) increased, though not statistically significant. As for serum oxidation assay, significant decrease in antioxidant activity was observed as concentration of FRF increased, while CE showed no significant difference in inhibitory activity across the concentrations used. The IC 50 values for ACE inhibitory activity of CE (0.03-0.42mg/mL) were lower than that of FRF (0.94-1.53mg/mL). When compared to reference drug Voglibose (IC 50 value of 0.61mg/mL) in the effectiveness in inhibiting α-amylase, CE (0.58mg/mL) gave significantly lower IC 50 values while FRF (0.68-0.71mg/mL) had significantly higher IC 50 values. The α-glucosidase inhibitory activity of CE (IC 50 value of 0.57-0.69mg/mL) and FRF (IC 50 value of 0.50-0.53mg/mL) were comparable to that of reference drug (IC 50 value of 0.54mg/mL). Results had shown the potential of S. siliquosum and S. polycystum in reducing cardiovascular diseases related risk factors following their inhibitory activities on ACE, α-amylase and α-glucosidase. In addition, it is likelihood that FRF possessed antioxidant activity at low concentration level. Copyright © 2017 Elsevier Ltd. All rights reserved.

Synthesis and evaluation of the antiplasmodial activity of tryptanthrin derivatives

PubMed Central

Onambele, Liliane Abodo; Riepl, Herbert; Fischer, Rainer; Pradel, Gabriele; Prokop, Aram; Aminake, Makoah Nigel

2015-01-01

Malaria remains one of the most deadly diseases threatening humankind and is still affecting a significant proportion of the world population, especially in Africa. Chemotherapy is a vital component of the fight against the disease and new antimalarial agents are urgently needed to curb the spread of malaria parasites that are resistant to existing drugs. The natural product tryptanthrin is known for its wide range of activities, including antiplasmodial activity, but its poor solubility has undermined its development as potent antimicrobial and antiprotozoan agent. The aim of this work was to synthesize analogues of tryptanthrin and to evaluate their antiplasmodial activity against the asexual and sexual blood stages of Plasmodium falciparum. Our results suggest that most tryptanthrin analogues retained their antiplasmodial activity against chloroquine-sensitive and chloroquine-resistant malaria parasites in the nanomolar range (30–100 nM). The antiplasmodial activity of the most active compound NT1 (IC50: 30 nM; SI: 155.9) was similar in both strains and close to that of chloroquine (IC50: 20 nM) on the sensitive strain. The antiplasmodial activity was improved with derivatization, thus pointing out the necessity to explore tryptanthrin using medicinal chemistry approaches. Ten (10) of the tested derivatives met the criteria, allowing for advancement to animal testing, i.e., SI > 100 and IC50 < 100 nM. In addition to their activity on the asexual stages, tryptanthrin and two selected derivatives (NT1 and T8) prevented the maturation of gametocytes at their IC90 concentrations, indicating a transmission-blocking potential. Moreover, NT1 was able to impair gametogenesis by reducing the exflagellation of microgametes by 20% at IC90, while tryptanthrin and T8 had no influence on exflagellation. The results of this study confirm that tryptanthrin and its derivatives are potential antimalarial candidates with abilities to kill the intraerythrocytic asexual stages and prevent the formation of sexual stages of the parasite. PMID:25949928

Synthesis and evaluation of the antiplasmodial activity of tryptanthrin derivatives.

PubMed

Onambele, Liliane Abodo; Riepl, Herbert; Fischer, Rainer; Pradel, Gabriele; Prokop, Aram; Aminake, Makoah Nigel

2015-08-01

Malaria remains one of the most deadly diseases threatening humankind and is still affecting a significant proportion of the world population, especially in Africa. Chemotherapy is a vital component of the fight against the disease and new antimalarial agents are urgently needed to curb the spread of malaria parasites that are resistant to existing drugs. The natural product tryptanthrin is known for its wide range of activities, including antiplasmodial activity, but its poor solubility has undermined its development as potent antimicrobial and antiprotozoan agent. The aim of this work was to synthesize analogues of tryptanthrin and to evaluate their antiplasmodial activity against the asexual and sexual blood stages of Plasmodium falciparum. Our results suggest that most tryptanthrin analogues retained their antiplasmodial activity against chloroquine-sensitive and chloroquine-resistant malaria parasites in the nanomolar range (30-100 nM). The antiplasmodial activity of the most active compound NT1 (IC50: 30 nM; SI: 155.9) was similar in both strains and close to that of chloroquine (IC50: 20 nM) on the sensitive strain. The antiplasmodial activity was improved with derivatization, thus pointing out the necessity to explore tryptanthrin using medicinal chemistry approaches. Ten (10) of the tested derivatives met the criteria, allowing for advancement to animal testing, i.e., SI > 100 and IC50 < 100 nM. In addition to their activity on the asexual stages, tryptanthrin and two selected derivatives (NT1 and T8) prevented the maturation of gametocytes at their IC90 concentrations, indicating a transmission-blocking potential. Moreover, NT1 was able to impair gametogenesis by reducing the exflagellation of microgametes by 20% at IC90, while tryptanthrin and T8 had no influence on exflagellation. The results of this study confirm that tryptanthrin and its derivatives are potential antimalarial candidates with abilities to kill the intraerythrocytic asexual stages and prevent the formation of sexual stages of the parasite.

Development of Quantum Chemical Method to Calculate Half Maximal Inhibitory Concentration (IC50 ).

PubMed

Bag, Arijit; Ghorai, Pradip Kr

2016-05-01

Till date theoretical calculation of the half maximal inhibitory concentration (IC50 ) of a compound is based on different Quantitative Structure Activity Relationship (QSAR) models which are empirical methods. By using the Cheng-Prusoff equation it may be possible to compute IC50 , but this will be computationally very expensive as it requires explicit calculation of binding free energy of an inhibitor with respective protein or enzyme. In this article, for the first time we report an ab initio method to compute IC50 of a compound based only on the inhibitor itself where the effect of the protein is reflected through a proportionality constant. By using basic enzyme inhibition kinetics and thermodynamic relations, we derive an expression of IC50 in terms of hydrophobicity, electric dipole moment (μ) and reactivity descriptor (ω) of an inhibitor. We implement this theory to compute IC50 of 15 HIV-1 capsid inhibitors and compared them with experimental results and available other QASR based empirical results. Calculated values using our method are in very good agreement with the experimental values compared to the values calculated using other methods. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Correlation between in vitro and in vivo antimalarial activity of compounds using CQ-sensitive and CQ-resistant strains of Plasmodium falciparum and CQ-resistant strain of P. yoelii.

PubMed

Srivastava, Kumkum; Agarwal, Pooja; Soni, Awakash; Puri, S K

2017-07-01

Present efforts have been made to establish a correlation between in vitro and in vivo antimalarial activity using MIC, IC 50 and IC 90 values against CQ-sensitive (3D7) and CQ-resistant (K1) strains of Plasmodium falciparum and in vivo activity against Plasmodium yoelii. The method of discriminant function analysis (DFA) was applied to analyze the data. It was observed that in vitro IC 90 values against both 3D7 and K1 strains (p < 0.001) have strong correlation with in vivo curative activity. The respective IC 50 and IC 90 values of compounds, which cured mice (i.e., animals did not show recrudescence of parasitemia even after 60 days posttreatment), ranged between 3 and 14 nM and 14 and 186 nM against 3D7 and between 9 and 65 nM and 24 and 359 nM against the K1 strain of P. falciparum. Whereas the IC 50 and IC 90 values of compounds which exhibited in vivo suppressive activity in mice ranged between 10 and 307 nm and 61 and >965 nM, respectively, against 3D7 and 75 and >806 nm and 241 and >1232 nM against the K1 strain of P. falciparum. The findings suggest that IC 90 values against both 3D7 and K1 strains (p < 0.02) are the main contributors for the prediction of in vivo curative activity of a new molecule. Apart from this, a reasonable correlation between MIC and IC 50 values of compounds has also been established.

Water-Soluble Ruthenium (II) Chiral Heteroleptic Complexes with Amoebicidal in Vitro and in Vivo Activity.

PubMed

Toledano-Magaña, Yanis; García-Ramos, Juan C; Torres-Gutiérrez, Carolina; Vázquez-Gasser, Cristina; Esquivel-Sánchez, José M; Flores-Alamo, Marcos; Ortiz-Frade, Luis; Galindo-Murillo, Rodrigo; Nequiz, Mario; Gudiño-Zayas, Marco; Laclette, Juan P; Carrero, Julio C; Ruiz-Azuara, Lena

2017-02-09

Three water-soluble Ru(II) chiral heteroleptic coordination compounds [Ru(en)(pdto)]Cl 2 (1), [Ru(gly)(pdto)]Cl (2), and [Ru(acac)(pdto)]Cl (3), where pdto = 2,2'-[1,2-ethanediylbis-(sulfanediyl-2,1-ethanediyl)]dipyridine, en = ethylendiamine, gly = glycinate, and acac = acetylacetonate, have been synthezised and fully characterized. The crystal structures of compounds 1-3 are described. The IC 50 values for compounds 1-3 are within nanomolar range (14, 12, and 6 nM, respectively). The cytotoxicity for human peripheral blood lymphocytes is extremely low (>100 μM). Selectivity indexes for Ru(II) compounds are in the range 700-1300. Trophozoites exposed to Ru(II) compounds die through an apoptotic pathway triggered by ROS production. The orally administration to infected mice induces a total elimination of the parasite charge in mice faeces 1-2-fold faster than metronidazole. Besides, all compounds inhibit the trophozoite proliferation in amoebic liver abscess induced in hamster. All our results lead us to propose these compounds as promising candidates as antiparasitic agents.

Novel donepezil-based inhibitors of acetyl- and butyrylcholinesterase and acetylcholinesterase-induced beta-amyloid aggregation.

PubMed

Camps, Pelayo; Formosa, Xavier; Galdeano, Carles; Gómez, Tània; Muñoz-Torrero, Diego; Scarpellini, Michele; Viayna, Elisabet; Badia, Albert; Clos, M Victòria; Camins, Antoni; Pallàs, Mercè; Bartolini, Manuela; Mancini, Francesca; Andrisano, Vincenza; Estelrich, Joan; Lizondo, Mònica; Bidon-Chanal, Axel; Luque, F Javier

2008-06-26

A novel series of donepezil-tacrine hybrids designed to simultaneously interact with the active, peripheral and midgorge binding sites of acetylcholinesterase (AChE) have been synthesized and tested for their ability to inhibit AChE, butyrylcholinesterase (BChE), and AChE-induced A beta aggregation. These compounds consist of a unit of tacrine or 6-chlorotacrine, which occupies the same position as tacrine at the AChE active site, and the 5,6-dimethoxy-2-[(4-piperidinyl)methyl]-1-indanone moiety of donepezil (or the indane derivative thereof), whose position along the enzyme gorge and the peripheral site can be modulated by a suitable tether that connects tacrine and donepezil fragments. All of the new compounds are highly potent inhibitors of bovine and human AChE and BChE, exhibiting IC50 values in the subnanomolar or low nanomolar range in most cases. Moreover, six out of the eight hybrids of the series, particularly those bearing an indane moiety, exhibit a significant A beta antiaggregating activity, which makes them promising anti-Alzheimer drug candidates.

Fluoro and pentafluorothio analogs of the antitumoral curcuminoid EF24 with superior antiangiogenic and vascular-disruptive effects.

PubMed

Schmitt, Florian; Gold, Madeleine; Begemann, Gerrit; Andronache, Ion; Biersack, Bernhard; Schobert, Rainer

2017-09-01

A series of 14 analogs of the curcuminoid EF24, (3E,5E)-3,5-bis[(2-fluorophenyl)methylene]-4-piperidinone, bearing fluorine or pentafluorothio substituents, were prepared and tested for antiproliferative, vascular-disruptive, and antiangiogenic activity, as well as for their influence on other cancer-relevant targets. They proved antiproliferative against eight cancer cell lines with IC 50 values in the low single-digit micromolar to triple-digit nanomolar range. Like EF24, the hexafluoro 3c and 3d and bis(pentafluorothio) 4f derivatives arrested HT-29 colon carcinoma cells in G2/M phase of the cell cycle, yet inhibited angiogenesis, e.g. in zebrafish larvae, to a much greater extent. The antimigratory effects in 518A2 melanoma cells of 3c, its regioisomer 3d, and of 4f, originate from an inhibition of NF-κB translocation. Moreover, 3c and 3d showed potential as vascular-disruptive agents in chorioallantoic/vitelline membrane (CA/VM) assays. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ganoboninketals A-C, Antiplasmodial 3,4-seco-27-Norlanostane Triterpenes from Ganoderma boninense Pat.

PubMed

Ma, Ke; Ren, Jinwei; Han, Junjie; Bao, Li; Li, Li; Yao, Yijian; Sun, Chen; Zhou, Bing; Liu, Hongwei

2014-08-22

Three new nortriterpenes, ganoboninketals A-C (1-3), featuring rearranged 3,4-seco-27-norlanostane skeletons and highly complex polycyclic systems were isolated from the medicinal mushroom Ganoderma boninense. The structures of the new metabolites were established by spectroscopic methods. The absolute configurations in 1-3 were assigned by electronic circular dichroism (ECD) calculations. Compounds 1-3 showed antiplasmodial activity against Plasmodium falciparum with IC50 values of 4.0, 7.9, and 1.7 μM, respectively. Compounds 1 and 3 also displayed weak cytotoxicity against A549 cell line with IC50 values of 47.6 and 35.8 μM, respectively. Compound 2 showed weak cytotoxicity toward HeLa cell line with an IC50 value of 65.5 μM. Compounds 1-3 also presented NO inhibitory activity in the LPS-induced macrophages with IC50 values of 98.3, 24.3, and 60.9 μM, respectively.

A Novel Two-Step Hierarchial Quantitative Structure-Activity ...

EPA Pesticide Factsheets

Background: Accurate prediction of in vivo toxicity from in vitro testing is a challenging problem. Large public–private consortia have been formed with the goal of improving chemical safety assessment by the means of high-throughput screening. Methods and results: A database containing experimental cytotoxicity values for in vitro half-maximal inhibitory concentration (IC50) and in vivo rodent median lethal dose (LD50) for more than 300 chemicals was compiled by Zentralstelle zur Erfassung und Bewertung von Ersatz- und Ergaenzungsmethoden zum Tierversuch (ZEBET ; National Center for Documentation and Evaluation of Alternative Methods to Animal Experiments) . The application of conventional quantitative structure–activity relationship (QSAR) modeling approaches to predict mouse or rat acute LD50 values from chemical descriptors of ZEBET compounds yielded no statistically significant models. The analysis of these data showed no significant correlation between IC50 and LD50. However, a linear IC50 versus LD50 correlation could be established for a fraction of compounds. To capitalize on this observation, we developed a novel two-step modeling approach as follows. First, all chemicals are partitioned into two groups based on the relationship between IC50 and LD50 values: One group comprises compounds with linear IC50 versus LD50 relationships, and another group comprises the remaining compounds. Second, we built conventional binary classification QSAR models t

Metformin and Its Sulfenamide Prodrugs Inhibit Human Cholinesterase Activity.

PubMed

Markowicz-Piasecka, Magdalena; Sikora, Joanna; Mateusiak, Łukasz; Mikiciuk-Olasik, Elżbieta; Huttunen, Kristiina M

2017-01-01

The results of epidemiological and pathophysiological studies suggest that type 2 diabetes mellitus (T2DM) may predispose to Alzheimer's disease (AD). The two conditions present similar glucose levels, insulin resistance, and biochemical etiologies such as inflammation and oxidative stress. The diabetic state also contributes to increased acetylcholinesterase (AChE) activity, which is one of the factors leading to neurodegeneration in AD. The aim of this study was to assess in vitro the effects of metformin, phenformin, and metformin sulfenamide prodrugs on the activity of human AChE and butyrylcholinesterase (BuChE) and establish the type of inhibition. Metformin inhibited 50% of the AChE activity at micromolar concentrations (2.35  μ mol/mL, mixed type of inhibition) and seemed to be selective towards AChE since it presented low anti-BuChE activity. The tested metformin prodrugs inhibited cholinesterases (ChE) at nanomolar range and thus were more active than metformin or phenformin. The cyclohexyl sulfenamide prodrug demonstrated the highest activity towards both AChE (IC 50  = 890 nmol/mL, noncompetitive inhibition) and BuChE (IC 50  = 28 nmol/mL, mixed type inhibition), while the octyl sulfenamide prodrug did not present anti-AChE activity, but exhibited mixed inhibition towards BuChE (IC 50  = 184 nmol/mL). Therefore, these two bulkier prodrugs were concluded to be the most selective compounds for BuChE over AChE. In conclusion, it was demonstrated that biguanides present a novel class of inhibitors for AChE and BuChE and encourages further studies of these compounds for developing both selective and nonselective inhibitors of ChEs in the future.

Regulation of Na+-K+-2Cl− cotransport by protein phosphorylation in ferret erythrocytes

PubMed Central

Flatman, Peter W; Creanor, James

1999-01-01

Na+-K+-2Cl− cotransport in ferret erythrocytes was measured as the bumetanide-sensitive uptake of 86Rb. The resting cotransport rate was high but could be increased threefold by treating erythrocytes with calyculin A, a potent inhibitor of serine/threonine phosphatases. Twenty nanomolar was sufficient to maximally and rapidly (within 4 min) stimulate transport. The effects of several kinase inhibitors were tested. High concentrations of K-252a, K-252b, calphostin C and hypericin caused less than 20 % inhibition. Staurosporine (IC50, 0.06 μm) and 4-amino-5-(4-methylphenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine (PP1; IC50, 2.5 μm) were more potent but still only partially (40–50 %) inhibited transport, an effect mimicked by reducing ionized intracellular Mg2+ concentration to submicromolar levels. Genistein may inhibit all transport at a sufficiently high dose (IC50, 0.36 mM) perhaps by directly inhibiting the transporter. Staurosporine, PP1 and the removal of Mg2+ all prevented subsequent stimulation by calyculin A, and all inhibited calyculin-stimulated transport by 20–30 %. The effects of staurosporine, PP1 and Mg2+ removal were not additive. The phosphatase that dephosphorylates the cotransporter is probably Mg2+ (or possibly Ca2+ or Mn2+) sensitive and not the target for calyculin A. The data suggest that this phosphatase is inhibited by phosphorylation, and that it is the regulation of this process which is affected by calyculin A and the kinase inhibitors tested here. Phosphorylation of the phosphatase is probably regulated by members of the Src family of tyrosine kinases. PMID:10358111

6-Nitrobenzimidazole derivatives: potential phosphodiesterase inhibitors: synthesis and structure-activity relationship.

PubMed

Khan, K M; Shah, Zarbad; Ahmad, V U; Ambreen, N; Khan, M; Taha, M; Rahim, F; Noreen, S; Perveen, S; Choudhary, M I; Voelter, W

2012-02-15

6-Nitrobenzimidazole derivatives (1-30) synthesized and their phosphodiesterase inhibitory activities determined. Out of thirty tested compounds, ten showed a varying degrees of phosphodiesterase inhibition with IC(50) values between 1.5±0.043 and 294.0±16.7 μM. Compounds 30 (IC(50)=1.5±0.043 μM), 1 (IC(50)=2.4±0.049 μM), 11 (IC(50)=5.7±0.113 μM), 13 (IC(50)=6.4±0.148 μM), 14 (IC(50)=10.5±0.51 μM), 9 (IC(50)=11.49±0.08 μM), 3 (IC(50)=63.1±1.48 μM), 10 (IC(50)=120.0±4.47 μM), and 6 (IC(50)=153.2±5.6 μM) showed excellent phosphodiesterase inhibitory activity, much superior to the standard EDTA (IC(50)=274±0.007 μM), and thus are potential molecules for the development of a new class of phosphodiesterase inhibitors. A structure-activity relationship is evaluated. All compounds are characterized by spectroscopic parameters. Copyright © 2011 Elsevier Ltd. All rights reserved.

In vitro evaluation of novel antiviral activities of 60 medicinal plants extracts against hepatitis B virus.

PubMed

Arbab, Ahmed Hassan; Parvez, Mohammad Khalid; Al-Dosari, Mohammed Salem; Al-Rehaily, Adnan Jathlan

2017-07-01

Currently, >35 Saudi Arabian medicinal plants are traditionally used for various liver disorders without a scientific rationale. This is the first experimental evaluation of the anti-hepatitis B virus (HBV) potential of the total ethanolic and sequential organic extracts of 60 candidate medicinal plants. The extracts were tested for toxicity on HepG2.2.15 cells and cytotoxicity concentration (CC 50 ) values were determined. The extracts were further investigated on HepG2.2.15 cells for anti-HBV activities by analyzing the inhibition of HBsAg and HBeAg production in the culture supernatants, and their half maximal inhibitory concentration (IC 50 ) and therapeutic index (TI) values were determined. Of the screened plants, Guiera senegalensis (dichloromethane extract, IC 50 =10.65), Pulicaria crispa (ethyl acetate extract, IC 50 =14.45), Coccinea grandis (total ethanol extract, IC 50 =31.57), Fumaria parviflora (hexane extract, IC 50 =35.44), Capparis decidua (aqueous extract, IC 50 =66.82), Corallocarpus epigeus (total ethanol extract, IC 50 =71.9), Indigofera caerulea (methanol extract, IC 50 =73.21), Abutilon figarianum (dichloromethane extract, IC 50 =99.76) and Acacia oerfota (total ethanol extract, IC 50 =101.46) demonstrated novel anti-HBV activities in a time- and dose-dependent manner. Further qualitative phytochemical analysis of the active extracts revealed the presence of alkaloids, tannins, flavonoids and saponins, which are attributed to antiviral efficacies. In conclusion, P. crispa, G. senegalensis and F. parviflora had the most promising anti-HBV potentials, including those of C. decidua , C. epigeus, A. figarianum , A. oerfota and I. caerulea with marked activities. However, a detailed phytochemical study of these extracts is essential to isolate the active principle(s) responsible for their novel anti-HBV potential.

Terpenes increase the lipid dynamics in the Leishmania plasma membrane at concentrations similar to their IC50 values.

PubMed

Camargos, Heverton Silva; Moreira, Rodrigo Alves; Mendanha, Sebastião Antonio; Fernandes, Kelly Souza; Dorta, Miriam Leandro; Alonso, Antonio

2014-01-01

Although many terpenes have shown antitumor, antibacterial, antifungal, and antiparasitic activity, the mechanism of action is not well established. Electron paramagnetic resonance (EPR) spectroscopy of the spin-labeled 5-doxyl stearic acid revealed remarkable fluidity increases in the plasma membrane of terpene-treated Leishmania amazonensis promastigotes. For an antiproliferative activity assay using 5×10(6) parasites/mL, the sesquiterpene nerolidol and the monoterpenes (+)-limonene, α-terpineol and 1,8-cineole inhibited the growth of the parasites with IC50 values of 0.008, 0.549, 0.678 and 4.697 mM, respectively. The IC50 values of these terpenes increased as the parasite concentration used in the cytotoxicity assay increased, and this behavior was examined using a theoretical treatment of the experimental data. Cytotoxicity tests with the same parasite concentration as in the EPR experiments revealed a correlation between the IC50 values of the terpenes and the concentrations at which they altered the membrane fluidity. In addition, the terpenes induced small amounts of cell lysis (4-9%) at their respective IC50 values. For assays with high cell concentrations (2×10(9) parasites/mL), the incorporation of terpene into the cell membrane was very fast, and the IC50 values observed for 24 h and 5 min-incubation periods were not significantly different. Taken together, these results suggest that terpene cytotoxicity is associated with the attack on the plasma membrane of the parasite. The in vitro cytotoxicity of nerolidol was similar to that of miltefosine, and nerolidol has high hydrophobicity; thus, nerolidol might be used in drug delivery systems, such as lipid nanoparticles to treat leishmaniasis.

Terpenes Increase the Lipid Dynamics in the Leishmania Plasma Membrane at Concentrations Similar to Their IC50 Values

PubMed Central

Camargos, Heverton Silva; Moreira, Rodrigo Alves; Mendanha, Sebastião Antonio; Fernandes, Kelly Souza; Dorta, Miriam Leandro; Alonso, Antonio

2014-01-01

Although many terpenes have shown antitumor, antibacterial, antifungal, and antiparasitic activity, the mechanism of action is not well established. Electron paramagnetic resonance (EPR) spectroscopy of the spin-labeled 5-doxyl stearic acid revealed remarkable fluidity increases in the plasma membrane of terpene-treated Leishmania amazonensis promastigotes. For an antiproliferative activity assay using 5×106 parasites/mL, the sesquiterpene nerolidol and the monoterpenes (+)-limonene, α-terpineol and 1,8-cineole inhibited the growth of the parasites with IC50 values of 0.008, 0.549, 0.678 and 4.697 mM, respectively. The IC50 values of these terpenes increased as the parasite concentration used in the cytotoxicity assay increased, and this behavior was examined using a theoretical treatment of the experimental data. Cytotoxicity tests with the same parasite concentration as in the EPR experiments revealed a correlation between the IC50 values of the terpenes and the concentrations at which they altered the membrane fluidity. In addition, the terpenes induced small amounts of cell lysis (4–9%) at their respective IC50 values. For assays with high cell concentrations (2×109 parasites/mL), the incorporation of terpene into the cell membrane was very fast, and the IC50 values observed for 24 h and 5 min-incubation periods were not significantly different. Taken together, these results suggest that terpene cytotoxicity is associated with the attack on the plasma membrane of the parasite. The in vitro cytotoxicity of nerolidol was similar to that of miltefosine, and nerolidol has high hydrophobicity; thus, nerolidol might be used in drug delivery systems, such as lipid nanoparticles to treat leishmaniasis. PMID:25101672

Discovery of a series of novel phenylpiperazine derivatives as EGFR TK inhibitors

NASA Astrophysics Data System (ADS)

Sun, Juan; Wang, Xin-Yi; Lv, Peng-Cheng; Zhu, Hai-Liang

2015-09-01

Human epidermal growth factor receptor (EGFR) is an important drug target that plays a fundamental role in signal transduction pathways in oncology. We report herein the discovery of a novel class of phenylpiperazine derivatives with improved potency toward EGFR. The biological activity of compound 3p as inhibitor of EGFR was further investigated both in vitro and in vivo. Notably, compound 3p exhibited an IC50 in the nanomolar range in A549 cell cultures and induced a cessation of tumor growth with no toxicity, as determined by loss of body weight and death of treated mice. Compoutational docking studies also showed that compound 3p has interaction with EGFR key residues in the active site.

Human and mouse homo-oligomeric meprin A metalloendopeptidase: substrate and inhibitor specificities.

PubMed

Bylander, John E; Bertenshaw, Greg P; Matters, Gail L; Hubbard, Simon J; Bond, Judith S

2007-11-01

Meprin metalloproteinases have been implicated in the susceptibility to and progression of diabetic nephropathy and inflammatory bowel diseases. Our studies with experimental models of these diseases in mice are congruent with the conclusion that meprins modulate the inflammatory responses and tissue damage. To determine whether the mouse and human enzymes differ, recombinant forms of meprin A from the two species were compared with respect to structure, substrates and inhibitors. Human homo-oligomeric meprin A formed oligomers ranging from 950,000 to 1,500,000 Da vs. 900,000 Da for mouse meprin A. Human and mouse meprin A exhibited similar activity against azocasein, fibronectin, collagen IV, and peptides such as parathyroid hormone, ghrelin, and gastrin-releasing peptide. The human enzyme had lower activity against gelatin, bradykinin, alpha-melanocyte-stimulating hormone and neurotensin, and higher activity against secretin and orcokinin. Human meprin A showed a preference for acidic residues in the P1' position of the substrate, unlike mouse meprin A. Several metalloproteinase inhibitors had IC(50) values in the nanomolar range, but potency ranged from similar values to a difference of several orders of magnitude for meprins from the two species. This work provides valuable data to improve predictability for human systems based on meprin functions in mouse models.

The Anti-Inflammatory Activity of Boron Derivatives in Rodents

PubMed Central

Hall, Iris H.; Burnham, Bruce S.; Chen, Shang Y.; Sood, Anup; Spielvogel, Bernard F.; Morse, Karen W.

1995-01-01

Acyclic amine-carboxyboranes were effective anti-inflammatory agents in mice at 8 mg/kg x 2. These amine-carboxyboranes were more effective than the standard indomethacin at 8 mg/kg x 2, pentoxifylline at 50 mg/kg x 2, and phenylbutazone at 50 mg/kg x 2. The heterocyclic amine derivatives as well as amine-carbamoylboranes, carboalkoxyboranes, and cyanoboranes were generally less active. However, selected aminomethyl-phosphonate-N-cyanoboranes demonstrated greater than 60% reduction of induced inflammation. The boron compounds were also active in the rat induced edema, chronic arthritis, and pleurisy screens, demonstrating activity similar to the standard indomethacin. The compounds were effecive in reducing local pain and decreased the tail flick reflex to pain. The derivatives which demonstrated good anti-inflammatory activity were effective inhibitors of hydrolytic lysosomal, and proteolytic enzyme activities with IC50 50 values equal to -6M in mouse macrophages, human leukocytes, and Be Sal osteofibrolytic cells. In these same cell lines, the agents blocked prostaglandin cyclooxygenase activity with IC50 values of -6M. In mouse macrophage and human leukocytes, 5′ lipoxygenase activity was also inhibited by the boron derivatives with IC50 values of 10-6M. These IC50 values for inhibition of these enzyme activities are consistent with published values of known anti-inflammatory agents which target these enzymes. PMID:18472741

Novel oxazine skeletons as potential antiplasmodial active ingredients: Synthesis, in vitro and in vivo biology of some oxazine entities produced via cyclization of novel chalcone intermediates.

PubMed

Tiwari, Vandana; Meshram, Jyotsna; Ali, Parvez; Sheikh, Javed; Tripathi, Umanath

2011-08-01

A novel series of 6-(2-chloroquinolin-3-yl)-4-substituted-phenyl-6H-1,3-oxazin-2-amines were synthesized and evaluated for in vitro antimalarial efficacy against chloroquine sensitive (MRC-02) as well as chloroquine resistant (RKL9) strains of Plasmodium falciparum. The activity tested was at nanomolar concentration. β-Hematin formation inhibition activity (BHIA(50)) of oxazines were determined and correlated with antimalarial activity. A reasonably good correlation (r = 0.49 and 0.51, respectively) was observed between antimalarial activity (IC(50)) and BHIA(50). This suggests that antimalarial mode of action of these compounds seems to be similar to that of chloroquine and involves the inhibition of hemozoin formation. Some of the compounds were showing better antimalarial activity than chloroquine against resistant strain of P. falciparum and were also found to be active in the in vivo experiment.

Neurotoxicity screening of new psychoactive substances (NPS): Effects on neuronal activity in rat cortical cultures using microelectrode arrays (MEA).

PubMed

Zwartsen, Anne; Hondebrink, Laura; Westerink, Remco Hs

2018-05-01

While the prevalence and the use of new psychoactive substances (NPS) is steadily increasing, data on pharmacological, toxicological and clinical effects is limited. Considering the large number of NPS available, there is a clear need for efficient in vitro screening techniques that capture multiple mechanisms of action. Neuronal cultures grown on multi-well microelectrode arrays (mwMEAs) have previously proven suitable for neurotoxicity screening of chemicals, pharmaceuticals and (illicit) drugs. We therefore used rat primary cortical cultures grown on mwMEA plates to investigate the effects of eight NPS (PMMA, α-PVP, methylone, MDPV, 2C-B, 25B-NBOMe, BZP and TFMPP) and two 'classic' illicit drugs (cocaine, methamphetamine) on spontaneous neuronal activity. All tested drugs rapidly and concentration-dependently decreased the weighted mean firing rate (wMFR) and the weighted mean burst rate (wMBR) during a 30 min acute exposure. Of the 'classic' drugs, cocaine most potently inhibited the wMFR (IC 50 9.8 μM), whereas methamphetamine and the structurally-related NPS PMMA were much less potent (IC 50 100 μM and IC 50 112 μM, respectively). Of the cathinones, MDPV and α-PVP showed comparable IC 50 values (29 μM and 21 μM, respectively), although methylone was 10-fold less potent (IC 50 235 μM). Comparable 10-fold differences in potency were also observed between the hallucinogenic phenethylamines 2C-B (IC 50 27 μM) and 25B-NBOMe (IC 50 2.4 μM), and between the piperazine derivatives BZP (IC 50 161 μM) and TFMPP (IC 50 19 μM). All drugs also inhibited the wMBR and concentration-response curves for wMBR and wMFR were comparable. For most drugs, IC 50 values are close to the estimated human brain concentrations following recreational doses of these drugs, highlighting the importance of this efficient in vitro screening approach for classification and prioritization of emerging NPS. Moreover, the wide range of IC 50 values observed for these and previously tested drugs of abuse, both within and between different classes of NPS, indicates that additional investigation of structure-activity relationships could aid future risk assessment of emerging NPS. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

X-ray structural studies of quinone reductase 2 nanomolar range inhibitors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pegan, Scott D.; Sturdy, Megan; Ferry, Gilles

Quinone reductase 2 (QR2) is one of two members comprising the mammalian quinone reductase family of enzymes responsible for performing FAD mediated reductions of quinone substrates. In contrast to quinone reductase 1 (QR1) which uses NAD(P)H as its co-substrate, QR2 utilizes a rare group of hydride donors, N-methyl or N-ribosyl nicotinamide. Several studies have linked QR2 to the generation of quinone free radicals, several neuronal degenerative diseases, and cancer. QR2 has been also identified as the third melatonin receptor (MT3) through in cellulo and in vitro inhibition of QR2 by traditional MT3 ligands, and through recent X-ray structures of humanmore » QR2 (hQR2) in complex with melatonin and 2-iodomelatonin. Several MT3 specific ligands have been developed that exhibit both potent in cellulo inhibition of hQR2 nanomolar, affinity for MT3. The potency of these ligands suggest their use as molecular probes for hQR2. However, no definitive correlation between traditionally obtained MT3 ligand affinity and hQR2 inhibition exists limiting our understanding of how these ligands are accommodated in the hQR2 active site. To obtain a clearer relationship between the structures of developed MT3 ligands and their inhibitory properties, in cellulo and in vitro IC{sub 50} values were determined for a representative set of MT3 ligands (MCA-NAT, 2-I-MCANAT, prazosin, S26695, S32797, and S29434). Furthermore, X-ray structures for each of these ligands in complex with hQR2 were determined allowing for a structural evaluation of the binding modes of these ligands in relation to the potency of MT3 ligands.« less

Betulin derivatives impair Leishmania braziliensis viability and host-parasite interaction.

PubMed

Alcazar, Wilmer; López, Adrian Silva; Alakurtti, Sami; Tuononen, Maija-Liisa; Yli-Kauhaluoma, Jari; Ponte-Sucre, Alicia

2014-11-01

Leishmaniasis is a public health problem in tropical and subtropical areas of the world, including Venezuela. The incidence of treatment failure and the number of cases with Leishmania-HIV co-infection underscore the importance of developing alternative, economical and effective therapies against this disease. The work presented here analyzed whether terpenoids derived from betulin are active against New World Leishmania parasites. Initially we determined the concentration that inhibits the growth of these parasites by 50% or IC50, and subsequently evaluated the chemotactic effect of four compounds with leishmanicidal activity in the sub-micromolar and micromolar range. That is, we measured the migratory capacity of Leishmania (V.) braziliensis in the presence of increasing concentrations of compounds. Finally, we evaluated their cytotoxicity against the host cell and their effect on the infectivity of L. (V.) braziliensis. The results suggest that (1) compounds 14, 17, 18, 25 and 27 are active at concentrations lower than 10 μM; (2) compound 26 inhibits parasite growth with an IC50 lower than 1 μM; (3) compounds 18, 26 and 27 inhibit parasite migration at pico- to nanomolar concentrations, suggesting that they impair host-parasite interaction. None of the tested compounds was cytotoxic against J774.A1 macrophages thus indicating their potential as starting points to develop compounds that might affect parasite-host cell interaction, as well as being leishmanicidal. Copyright © 2014 Elsevier Ltd. All rights reserved.

Cholinergic and neuroprotective drugs for the treatment of Alzheimer and neuronal vascular diseases. II. Synthesis, biological assessment, and molecular modelling of new tacrine analogues from highly substituted 2-aminopyridine-3-carbonitriles.

PubMed

Samadi, Abdelouahid; Valderas, Carolina; de los Ríos, Cristóbal; Bastida, Agatha; Chioua, Mourad; González-Lafuente, Laura; Colmena, Inés; Gandía, Luis; Romero, Alejandro; Del Barrio, Laura; Martín-de-Saavedra, María D; López, Manuela G; Villarroya, Mercedes; Marco-Contelles, José

2011-01-01

The synthesis, biological assessment, and molecular modelling of new tacrine analogues 11-22 is described. Compounds 11-22 have been obtained by Friedländer-type reaction of 2-aminopyridine-3-carbonitriles 1-10 with cyclohexanone or 1-benzyl-4-piperidone. The biological evaluation showed that some of these molecules were good AChE inhibitors, in the nanomolar range, and quite selective regarding the inhibition of BuChE, the most potent being 5-amino-2-(dimethylamino)-6,7,8,9-tetrahydrobenzo[1,8-b]-naphthyridine-3-carbonitrile (11) [IC(50) (EeAChE: 14nM); IC(50) (eqBuChE: 5.2μM]. Kinetic studies on the easily available and potent anticholinesterasic compound 5-amino-2-(methoxy)-6,7,8,9-tetrahydrobenzo[1,8-b]-naphthyridine-3-carbonitrile (16) [IC(50) (EeAChE: 64nM); IC(50) (eqBuChE: 9.6μM] showed that this compound is a mixed-type inhibitor (K(i)=69.2nM) of EeAChE. Molecular modelling on inhibitor 16 confirms that this compound, as expected and similarly to tacrine, binds at the catalytic active site of EeAChE. The neuroprotective profile of molecules 11-22 has been investigated in SH-SY5Y neuroblastoma cells stressed with a mixture of oligomycin-A/rotenone. Compound 16 was also able to rescue by 50% cell death induced by okadaic acid in SH-SY5Y cells. From these results we conclude that the neuroprotective profile of these molecules is moderate, the most potent being compounds 12 and 17 which reduced cell death by 29%. Compound 16 does not affect ACh- nor K(+)-induced calcium signals in bovine chromaffin cells. Consequently, tacrine analogues 11-22 can be considered attractive therapeutic molecules on two key pharmacological targets playing key roles in the progression of Alzheimer, that is, cholinergic dysfunction and oxidative stress, as well as in neuronal cerebrovascular diseases. Copyright © 2010. Published by Elsevier Ltd.

Molecular rationale delineating the role of lycopene as a potent HMG-CoA reductase inhibitor: in vitro and in silico study.

PubMed

Alvi, Sahir Sultan; Iqbal, Danish; Ahmad, Saheem; Khan, M Salman

2016-09-01

This study initially aimed to depict the molecular rationale evolving the role of lycopene in inhibiting the enzymatic activity of β-hydroxy-β-methylglutaryl-CoA (HMG-CoA) reductase via in vitro and in silico analysis. Our results illustrated that lycopene exhibited strong HMG-CoA reductase inhibitory activity (IC50 value of 36 ng/ml) quite better than pravastatin (IC50 = 42 ng/ml) and strong DPPH free radical scavenging activity (IC50 value = 4.57 ± 0.23 μg/ml) as compared to ascorbic acid (IC50 value = 9.82 ± 0.42 μg/ml). Moreover, the Ki value of lycopene (36 ng/ml) depicted via Dixon plot was well concurred with an IC50 value of 36 ± 1.8 ng/ml. Moreover, molecular informatics study showed that lycopene exhibited binding energy of -5.62 kcal/mol indicating high affinity for HMG-CoA reductase than HMG-CoA (ΔG: -5.34 kcal/mol). Thus, in silico data clearly demonstrate and support the in vitro results that lycopene competitively inhibit HMG-CoA reductase activity by binding at the hydrophobic portion of HMG-CoA reductase.

Inhibitors of 15-lipoxygenase from orange peel.

PubMed

Malterud, K E; Rydland, K M

2000-11-01

A series of polymethoxylated flavonoids has been isolated from orange peel, and their inhibitory activity toward soybean 15-lipoxygenase was determined. The strongest inhibition was shown by 3,5,6,7,3',4'-hexamethoxyflavone (IC(50) = 49 +/- 5 microM). Sinensetin, nobiletin, tangeretin, tetramethylscutellarein, and 3,5, 6,7,8,3',4'-heptamethoxyflavone were somewhat less active, with IC(50) values of 70-86 microM, comparable to the positive control quercetin (IC(50) = 68 +/- 5 microM). Demethylation apparently results in less active compounds, with 5-O-demethylsinensetin having an IC(50) value of 144 +/- 10 microM. Some other orange peel constituents were isolated and tested as well, hesperidin (IC(50) = 180 +/- 10 microM) and ferulic acid (111 +/- 2 microM), showing moderate activity. The polymethoxylated flavonoids were virtually inactive as scavengers of the diphenylpicrylhydrazyl radical. Hesperidin was only slightly active (24.2 +/- 0.7% scavenged at a concentration of 2 mM), and ferulic acid showed good activity (IC(50) = 86.4 +/- 0.7 microM). From this, it appears that orange peel constituents may counteract enzymatic lipid peroxidation processes catalyzed by 15-lipoxygenase in vitro. The radical scavenging activity of orange peel extracts is only modest.

A novel application of t-statistics to objectively assess the quality of IC50 fits for P-glycoprotein and other transporters.

PubMed

O'Connor, Michael; Lee, Caroline; Ellens, Harma; Bentz, Joe

2015-02-01

Current USFDA and EMA guidance for drug transporter interactions is dependent on IC50 measurements as these are utilized in determining whether a clinical interaction study is warranted. It is therefore important not only to standardize transport inhibition assay systems but also to develop uniform statistical criteria with associated probability statements for generation of robust IC50 values, which can be easily adopted across the industry. The current work provides a quantitative examination of critical factors affecting the quality of IC50 fits for P-gp inhibition through simulations of perfect data with randomly added error as commonly observed in the large data set collected by the P-gp IC50 initiative. The types of errors simulated were (1) variability in replicate measures of transport activity; (2) transformations of error-contaminated transport activity data prior to IC50 fitting (such as performed when determining an IC50 for inhibition of P-gp based on efflux ratio); and (3) the lack of well defined "no inhibition" and "complete inhibition" plateaus. The effect of the algorithm used in fitting the inhibition curve (e.g., two or three parameter fits) was also investigated. These simulations provide strong quantitative support for the recommendations provided in Bentz et al. (2013) for the determination of IC50 values for P-gp and demonstrate the adverse effect of data transformation prior to fitting. Furthermore, the simulations validate uniform statistical criteria for robust IC50 fits in general, which can be easily implemented across the industry. A calibration of the t-statistic is provided through calculation of confidence intervals associated with the t-statistic.

A novel application of t-statistics to objectively assess the quality of IC50 fits for P-glycoprotein and other transporters

PubMed Central

O'Connor, Michael; Lee, Caroline; Ellens, Harma; Bentz, Joe

2015-01-01

Current USFDA and EMA guidance for drug transporter interactions is dependent on IC50 measurements as these are utilized in determining whether a clinical interaction study is warranted. It is therefore important not only to standardize transport inhibition assay systems but also to develop uniform statistical criteria with associated probability statements for generation of robust IC50 values, which can be easily adopted across the industry. The current work provides a quantitative examination of critical factors affecting the quality of IC50 fits for P-gp inhibition through simulations of perfect data with randomly added error as commonly observed in the large data set collected by the P-gp IC50 initiative. The types of errors simulated were (1) variability in replicate measures of transport activity; (2) transformations of error-contaminated transport activity data prior to IC50 fitting (such as performed when determining an IC50 for inhibition of P-gp based on efflux ratio); and (3) the lack of well defined “no inhibition” and “complete inhibition” plateaus. The effect of the algorithm used in fitting the inhibition curve (e.g., two or three parameter fits) was also investigated. These simulations provide strong quantitative support for the recommendations provided in Bentz et al. (2013) for the determination of IC50 values for P-gp and demonstrate the adverse effect of data transformation prior to fitting. Furthermore, the simulations validate uniform statistical criteria for robust IC50 fits in general, which can be easily implemented across the industry. A calibration of the t-statistic is provided through calculation of confidence intervals associated with the t-statistic. PMID:25692007

The antioxidant activity test by using DPPH method from the white tea using different solvents

NASA Astrophysics Data System (ADS)

Darmajana, Doddy A.; Hadiansyah, Firman; Desnilasari, Dewi

2017-11-01

The solvents used in this study are: aquades, ethanol and glacial acetic acid. The raw material as the source of antioxidants is white tea. Pure Quercetin is used as a comparing antioxidant. The treatment design was the solvent type for extraction, while the antioxidant activity was tested using DPPH method, with IC50 as the reference of antioxidant activity value. The results of antioxidant activity tests with three different solvent types are IC50 of 22,499 µg/mL for aquades, IC50 of 13,317 µg/mL for Ethanol and IC50 of 60,555 µg/mL for Glacial Acetic Acid. As a control of the standard antioxidant activity value of Quercetin is 4,313 µg/mL.

A non-cytotoxic N-dehydroabietylamine derivative with potent antimalarial activity.

PubMed

Sadashiva, Maralinganadoddi P; Gowda, Raghavendra; Wu, Xianzhu; Inamdar, Gajanan S; Kuzu, Omer F; Rangappa, Kanchugarakoppal S; Robertson, Gavin P; Gowda, D Channe

2015-08-01

Malaria caused by the Plasmodium parasites continues to be an enormous global health problem owing to wide spread drug resistance of parasites to many of the available antimalarial drugs. Therefore, development of new classes of antimalarial agents is essential to effectively treat malaria. In this study, the efficacy of naturally occurring diterpenoids, dehydroabietylamine and abietic acid, and their synthetic derivatives was assessed for antimalarial activity. Dehydroabietylamine and its N-trifluoroacetyl, N-tribromoacetyl, N-benzoyl, and N-benzyl derivatives showed excellent activity against P. falciparum parasites with IC50 values of 0.36 to 2.6 µM. Interestingly, N-dehydroabietylbenzamide showed potent antimalarial activity (IC50 0.36), and negligible cytotoxicity (IC50 >100 µM) to mammalian cells; thus, this compound can be an important antimalarial drug. In contrast, abietic acid was only marginally effective, exhibiting an IC50 value of ~82 µM. Several carboxylic group-derivatives of abietic acid were moderately active with IC50 values of ~8.2 to ~13.3 µM. These results suggest that a detailed understanding of the structure-activity relationship of abietane diterpenoids might provide strategies to exploit this class of compounds for malaria treatment. Copyright © 2015 Elsevier Inc. All rights reserved.

PTP1B, α-glucosidase, and DPP-IV inhibitory effects for chromene derivatives from the leaves of Smilax china L.

PubMed

Zhao, Bing Tian; Le, Duc Dat; Nguyen, Phi Hung; Ali, Md Yousof; Choi, Jae-Sue; Min, Byung Sun; Shin, Heung Mook; Rhee, Hae Ik; Woo, Mi Hee

2016-06-25

Two new flavonoids, bismilachinone (11) and smilachinin (14), were isolated from the leaves of Smilax china L. together with 14 known compounds. Their structures were elucidated using spectroscopic methods. The PTP1B, α-glucosidase, and DPP-IV inhibitory activities of compounds 1-16 were evaluated at the molecular level. Among them, compounds 4, 7, and 10 showed moderate DPP-IV inhibitory activities with IC50 values of 20.81, 33.12, and 32.93 μM, respectively. Compounds 3, 4, 6, 11, 12, and 16 showed strong PTP1B inhibitory activities, with respective IC50 values of 7.62, 10.80, 0.92, 2.68, 9.77, and 24.17 μM compared with the IC50 value for the positive control (ursolic acid: IC50 = 1.21 μM). Compounds 2-7, 11, 12, 15, and 16 showed potent α-glucosidase inhibitory activities, with respective IC50 values of 8.70, 81.66, 35.11, 35.92, 7.99, 26.28, 11.28, 62.68, 44.32, and 70.12 μM. The positive control, acarbose, displayed an IC50 value of 175.84 μM. In the kinetic study for the PTP1B enzyme, compounds 6, 11, and 12 displayed competitive inhibition with Ki values of 3.20, 8.56, and 5.86 μM, respectively. Compounds 3, 4, and 16 showed noncompetitive inhibition with Ki values of 18.75, 5.95, and 22.86 μM, respectively. Molecular docking study for the competitive inhibitors (6, 11, and 12) radically corroborates the binding affinities and inhibition of PTP1B enzymes. These results indicated that the leaves of Smilax china L. may contain compounds with anti-diabetic activity. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

2-Hexadecynoic acid inhibits plasmodial FAS-II enzymes and arrests erythrocytic and liver stage Plasmodium infections.

PubMed

Tasdemir, Deniz; Sanabria, David; Lauinger, Ina L; Tarun, Alice; Herman, Rob; Perozzo, Remo; Zloh, Mire; Kappe, Stefan H; Brun, Reto; Carballeira, Néstor M

2010-11-01

Acetylenic fatty acids are known to display several biological activities, but their antimalarial activity has remained unexplored. In this study, we synthesized the 2-, 5-, 6-, and 9-hexadecynoic acids (HDAs) and evaluated their in vitro activity against erythrocytic (blood) stages of Plasmodium falciparum and liver stages of Plasmodium yoelii infections. Since the type II fatty acid biosynthesis pathway (PfFAS-II) has recently been shown to be indispensable for liver stage malaria parasites, the inhibitory potential of the HDAs against multiple P. falciparum FAS-II (PfFAS-II) elongation enzymes was also evaluated. The highest antiplasmodial activity against blood stages of P. falciparum was displayed by 5-HDA (IC(50) value 6.6 μg/ml), whereas the 2-HDA was the only acid arresting the growth of liver stage P. yoelii infection, in both flow cytometric assay (IC(50) value 2-HDA 15.3 μg/ml, control drug atovaquone 2.5 ng/ml) and immunofluorescence analysis (IC(50) 2-HDA 4.88 μg/ml, control drug atovaquone 0.37 ng/ml). 2-HDA showed the best inhibitory activity against the PfFAS-II enzymes PfFabI and PfFabZ with IC(50) values of 0.38 and 0.58 μg/ml (IC(50) control drugs 14 and 30 ng/ml), respectively. Enzyme kinetics and molecular modeling studies revealed valuable insights into the binding mechanism of 2-HDA on the target enzymes. All HDAs showed in vitro activity against Trypanosoma brucei rhodesiense (IC(50) values 3.7-31.7 μg/ml), Trypanosoma cruzi (only 2-HDA, IC(50) 20.2 μg/ml), and Leishmania donovani (IC(50) values 4.1-13.4 μg/ml) with generally low or no significant toxicity on mammalian cells. This is the first study to indicate therapeutic potential of HDAs against various parasitic protozoa. It also points out that the malarial liver stage growth inhibitory effect of the 2-HDA may be promoted via PfFAS-II enzymes. The lack of cytotoxicity, lipophilic nature, and calculated pharmacokinetic properties suggests that 2-HDA could be a useful compound to study the interaction of fatty acids with these key P. falciparum enzymes. Copyright © 2010 Elsevier Ltd. All rights reserved.

2-Hexadecynoic Acid Inhibits Plasmodial FAS-II Enzymes and Arrest Erythrocytic and Liver Stage Plasmodium Infections

PubMed Central

Tasdemir, Deniz; Sanabria, David; Lauinger, Ina L.; Tarun, Alice; Herman, Rob; Perozzo, Remo; Zloh, Mire; Kappe, Stefan H.; Brun, Reto; Carballeira, Néstor M.

2010-01-01

Acetylenic fatty acids are known to display several biological activities, but their antimalarial activity has remained unexplored. In this study, we synthesized the 2-, 5-, 6-, and 9-hexadecynoic acids (HDAs) and evaluated their in vitro activity against erythrocytic (blood) stages of Plasmodium falciparum and liver stages of P. yoelii infections. Since the type II fatty acid biosynthesis pathway (PfFAS-II) has recently been shown to be indispensable for liver stage malaria parasites, the inhibitory potential of the HDAs against multiple P. falciparum FAS-II (PfFAS-II) elongation enzymes was also evaluated. The highest antiplasmodial activity against blood stages of P. falciparum was displayed by 5-HDA (IC50 value 6.6. μg/ml), whereas the 2-HDA was the only acid arresting the growth of liver stage P. yoelii infection, in both flow cytometric assay (IC50 value 2-HDA 15.3 μg/ml, control drug atovaquone 2.5 ng/ml) and immunofluorescense analysis (IC50 2-HDA 4.88 μg/ml, control drug atovaquone 0.37 ng/ml). 2-HDA showed the best inhibitory against the PfFAS-II enzymes PfFabI and PfFabZ with IC50 values of 0.38 and 0.58 μg/ml (IC50 control drugs 14 and 30 ng/ml) respectively. Enzyme kinetics and molecular modeling studies revealed valuable insights into the binding mechanism of 2-HDA on the target enzymes. All HDAs showed in vitro activity against Trypanosoma brucei rhodesiense (IC50 values 3.7–31.7 μg/ml), Trypanosoma cruzi (only 2-HDA, IC50 20.2 μg/ml), and Leishmania donovani (IC50 values 4.1–13.4 μg/ml) with generally low or no significant toxicity on mammalian cells. This is the first study to indicate therapeutic potential of HDAs against various parasitic protozoa. It also points out that the malarial liver stage growth inhibitory effect of the 2-HDA may be promoted via PfFAS-II enzymes. The lack of cytotoxicity, lipophilic nature and calculated pharmacokinetic properties suggest that 2-HDA could be a useful compound to study the interaction of fatty acids with these key P. falciparum enzymes. PMID:20855214

Synthesis and anti-parasitic activity of a novel quinolinone-chalcone series.

PubMed

Roussaki, Marina; Hall, Belinda; Lima, Sofia Costa; da Silva, Anabela Cordeiro; Wilkinson, Shane; Detsi, Anastasia

2013-12-01

A series of novel quinolinone-chalcone hybrids and analogues were designed, synthesized and their biological activity against the mammalian stages of Trypanosoma brucei and Leishmania infantum evaluated. Promising molecular scaffolds with significant microbicidal activity and low cytotoxicity were identified. Quinolinone-chalcone 10 exhibited anti-parasitic properties against both organisms, being the most potent anti-L. infantum agent of the entire series (IC50 value of 1.3±0.1 μM). Compounds 4 and 11 showed potency toward the intracellular, amastigote stage of L. infantum (IC50 values of 2.1±0.6 and 3.1±1.05 μM, respectively). Promising trypanocidal compounds include 5 and 10 (IC50 values of 2.6±0.1 and 3.3±0.1 μM, respectively) as well as 6 and 9 (both having IC50 values of <5 μM). Chemical modifications on the quinolinone-chalcone scaffold were performed on selected compounds in order to investigate the influence of these structural features on antiparasitic activity. Copyright © 2013 Elsevier Ltd. All rights reserved.

Synthesis, β-glucuronidase inhibition and molecular docking studies of hybrid bisindole-thiosemicarbazides analogs.

PubMed

Taha, Muhammad; Ismail, Nor Hadiani; Imran, Syahrul; Rahim, Fazal; Wadood, Abdul; Khan, Huma; Ullah, Hayat; Salar, Uzma; Khan, Khalid Mohammed

2016-10-01

Hybrid bisindole-thiosemicarbazides analogs (1-18) were synthesized and screened for β-glucuronidase activity. All compounds showed varied degree of β-glucuronidase inhibitory potential when compared with standard d-saccharic acid 1,4-lactone (IC50=48.4±1.25μM). Compounds 4, 7, 9, 6, 5, 12, 17 and 18 showed exceptional β-glucuronidase inhibition with IC50 values ranging from 0.1 to 5.7μM. Compounds 1, 3, 8, 16, 13, 2 and 14 also showed better activities than standard with IC50 values ranging from 7.12 to 15.0μM. The remaining compounds 10, 11, and 15 showed good inhibitory potential with IC50 values 33.2±0.75, 21.4±0.30 and 28.12±0.25μM respectively. Molecular docking studies were carried out to confirm the binding interaction of the compounds. Copyright © 2016 Elsevier Inc. All rights reserved.

Using in situ pore water concentrations to estimate the phytotoxicity of nicosulfuron in soils to corn (Zea mays L.).

PubMed

Liu, Kailin; Cao, Zhengya; Pan, Xiong; Yu, Yunlong

2012-08-01

The phytotoxicity of an herbicide in soil is typically dependent on the soil characteristics. To obtain a comparable value of the concentration that inhibits growth by 50% (IC50), 0.01 M CaCl(2) , excess pore water (EPW) and in situ pore water (IPW) were used to extract the bioavailable fraction of nicosulfuron from five different soils to estimate the nicosulfuron phytotoxicity to corn (Zea mays L.). The results indicated that the phytotoxicity of nicosulfuron in soils to corn depended on the soil type, and the IC50 values calculated based on the amended concentration of nicosulfuron ranged from 0.77 to 9.77 mg/kg among the five tested soils. The range of variation in IC50 values for nicosulfuron was smaller when the concentrations of nicosulfuron extracted with 0.01 M CaCl(2) and EPW were used instead of the amended concentration. No significant difference was observed among the IC50 values calculated from the IPW concentrations of nicosulfuron in the five tested soils, suggesting that the concentration of nicosulfuron in IPW could be used to estimate the phytotoxicity of residual nicosulfuron in soils. Copyright © 2012 SETAC.

Two new cytotoxic stilbenoid dimers isolated from Cajanus cajan.

PubMed

Zhang, Nenling; Shen, Xiangchun; Jiang, Xiaofei; Cai, Jiazhong; Shen, Xiaoling; Hu, Yingjie; Qiu, Samuel X

2018-01-01

Two new stilbenoid dimers, cajanstilbenoids A (1) and B (2), were isolated from the leaves of Cajanus cajan. Planar structures of these compounds were verified by NMR (1D and 2D) and high-resolution electrospray ionization mass spectroscopy (HR-ESI-MS). Absolute configurations were assigned by comparing experimental and calculated electronic CD values. The cytotoxicity of 1 and 2 against human hepatoma (HepG2), human breast adenocarcinoma (MCF-7), and human lung cancer (A549) cells were evaluated in vitro. Compound 1 showed strong cytotoxicity against all the tested cell lines (IC 50 values: 2.14-2.56 µM), whereas compound 2 showed strong toxicity only against HepG2 (IC 50 value: 5.99 µM) and A549 cells (IC 50 value: 6.18 µM).

Synthesis and in vitro cytotoxicity of 5-substituted 2-cyanoimino-4-imidazodinone and 2-cyanoimino-4-pyrimidinone derivatives.

PubMed

Chern, Jyh-Haur; Shia, Kak-Shan; Chang, Chung-Ming; Lee, Chung-Chi; Lee, Yen-Chun; Tai, Chia-Liang; Lin, Ying-Ting; Chang, Chih-Shiang; Tseng, Huan-Yi

2004-03-08

A series of 5-substituted 2-cyanoimino-4-imidazodinone and 2-cyanoimino-4-pyrimidinone derivatives were synthesized and their anticancer cytotoxicity were evaluated in in vitro assay. It was found that the bulky aryl functionality in the 5-position of the 2-cyanoimino-4-imidazolidinone compounds was essential for the cytotoxicity of these heterocyclic compounds. Some of the derivatives exhibited modest cytotoxicity against a variety of cancer cell lines. One of the derivatives, [1-[6-(4-chlorophenoxy)hexyl]-5-oxo-4-phenyl-3-(4-pyridyl)tetrahydro-1H-2-imidazolyliden]aminomethanenitrile (Compound 11), exhibited the most potent cytotoxic activity with IC(50) in the nanomolar range. The cytotoxicity of these derivatives was selection with no apparent toxic effect toward normal fibroblasts.

Selection of RNA Aptamers Against Botulinum Neurotoxin Type A Light Chain Through a Non-Radioactive Approach.

PubMed

Chang, Tzuu-Wang; Janardhanan, Pavithra; Mello, Charlene M; Singh, Bal Ram; Cai, Shuowei

2016-09-01

Botulinum neurotoxin (BoNT), a category A agent, is the most toxic molecule known to mankind. The endopeptidase activity of light chain domain of BoNT is the cause for the inhibition of the neurotransmitter release and the flaccid paralysis that leads to lethality in botulism. Currently, antidotes are not available to reverse the flaccid paralysis caused by BoNT. In the present study, a non-radioactive-based systematic evolution of ligands by exponential enrichment (SELEX) process is developed by utilizing surface plasmon resonance to monitor the binding enrichment. Two RNA aptamers have been identified as strong binders against light chain of botulinum neurotoxin type A. These two aptamers showed strong inhibition activity on LCA, with IC50 in nanomolar range. Inhibition kinetic studies reveal mid nanomolar KI and non-competitive nature of their inhibition, suggesting that they have strong potential as antidotes that can reverse the symptom caused by BoNT/A. More importantly, we observed that the 2'-fluorine-pyrimidine-modified RNA aptamers identified here do not change their binding and biological activities. This observation could lead to a cost-effective way for SELEX, by using regular nucleotide during SELEX, and 2'-fluorine-pyrimidine-modified nucleotide for final application to enhance their RNase-resistance.

Inhibition of Staphyloxanthin Virulence Factor Biosynthesis in Staphylococcus aureus: In Vitro, in Vivo, and Crystallographic Results†

PubMed Central

Song, Yongcheng; Liu, Chia-I; Lin, Fu-Yang; No, Joo Hwan; Hensler, Mary; Liu, Yi-Liang; Jeng, Wen-Yih; Low, Jennifer; Liu, George Y.; Nizet, Victor; Wang, Andrew H.-J.; Oldfield, Eric

2009-01-01

The gold color of Staphylococcus aureus is derived from the carotenoid staphyloxanthin, a virulence factor for the organism. Here, we report the synthesis and activity of a broad variety of staphyloxanthin biosynthesis inhibitors that inhibit the first committed step in its biosynthesis, condensation of two farnesyl diphosphate (FPP) molecules to dehydrosqualene, catalyzed by the enzyme dehydrosqualene synthase (CrtM). The most active compounds are phosphonoacetamides that have low nanomolar Ki values for CrtM inhibition and are active in whole bacterial cells and in mice, where they inhibit S. aureus disease progression. We also report the X-ray crystallographic structure of the most active compound, N-3-(3-phenoxyphenyl)propylphosphonoacetamide (IC50 = 8 nM, in cells), bound to CrtM. The structure exhibits a complex network of hydrogen bonds between the polar headgroup and the protein, while the 3-phenoxyphenyl side chain is located in a hydrophobic pocket previously reported to bind farnesyl thiodiphosphate (FsPP), as well as biphenyl phosphonosulfonate inhibitors. Given the good enzymatic, whole cell, and in vivo pharmacologic activities, these results should help guide the further development of novel antivirulence factor-based therapies for S. aureus infections. PMID:19456099

Synthesis and Biological Evaluation of Apogossypolone Derivatives as Pan-active Inhibitors of Anti-apoptotic B-Cell Lymphoma/Leukemia-2 (Bcl-2) Family Proteins

PubMed Central

Wei, Jun; Kitada, Shinichi; Stebbins, John L.; Placzek, William; Zhai, Dayong; Wu, Bainan; Rega, Michele F.; Zhang, Ziming; Cellitti, Jason; Yang, Li; Dahl, Russell; Reed, John C.; Pellecchia, Maurizio

2010-01-01

Overexpression of anti-apoptotic Bcl-2 family proteins is commonly related with tumor maintenance, progression, and chemoresistance. Inhibition of these anti-apoptotic proteins is an attractive approach for cancer therapy. Guided by nuclear magnetic resonance (NMR) binding assays, a series of 5, 5′ substituted compound 6a (Apogossypolone) derivatives was synthesized and identified pan-active antagonists of anti-apoptotic Bcl-2 family proteins, with binding potency in the low micromolar to nanomolar range. Compound 6f inhibits the binding of BH3 peptides to Bcl-XL, Bcl-2 and Mcl-1 with IC50 values of 3.10, 3.12 and 2.05 μM, respectively. In a cellular assay, 6f potently inhibits cell growth in several human cancer cell lines in a dose-dependent manner. Compound 6f further displays in vivo efficacy in transgenic mice and demonstrated superior single-agent antitumor efficacy in a PPC-1 mouse xenograft model. Together with its negligible toxicity, compound 6f represents a promising drug lead for the development of novel apoptosis-based therapies for cancer. PMID:21033669

Smart Photosensitizer: Tumor-Triggered Oncotherapy by Self-Assembly Photodynamic Nanodots.

PubMed

Jia, Yuhua; Li, Jinyu; Chen, Jincan; Hu, Ping; Jiang, Longguang; Chen, Xueyuan; Huang, Mingdong; Chen, Zhuo; Xu, Peng

2018-05-09

Clinical photosensitizers suffer from the disadvantages of fast photobleaching and high systemic toxicities because of the off-target photodynamic effects. To address these problems, we report a self-assembled pentalysine-phthalocyanine assembly nanodots (PPAN) fabricated by an amphipathic photosensitizer-peptide conjugate. We triggered the photodynamic therapy effects of photosensitizers by precisely controlling the assembly and disintegration of the nanodots. In physiological aqueous conditions, PPAN exhibited a size-tunable spherical conformation with a highly positive shell of the polypeptides and a hydrophobic core of the π-stacking Pc moieties. The assembly conformation suppressed the fluorescence and the reactive oxygen species generation of the monomeric photosensitizer molecules (mono-Pc) and thus declined the photobleaching and off-target photodynamic effects. However, tumor cells disintegrated PPAN and released the mono-Pc molecules, which exhibited fluorescence for detection and the photodynamic effects for the elimination of the tumor tissues. The molecular dynamics simulations revealed the various assembly configurations of PPAN and illustrated the assembly mechanism. At the cellular level, PPAN exhibited a remarkable phototoxicity to breast cancer cells with the IC 50 values in a low nanomolar range. By using the subcutaneous and orthotopic breast cancer animal models, we also demonstrated the excellent antitumor efficacies of PPAN in vivo.

Promising Tools in Prostate Cancer Research: Selective Non-Steroidal Cytochrome P450 17A1 Inhibitors

PubMed Central

Bonomo, Silvia; Hansen, Cecilie H.; Petrunak, Elyse M.; Scott, Emily E.; Styrishave, Bjarne; Jørgensen, Flemming Steen; Olsen, Lars

2016-01-01

Cytochrome P450 17A1 (CYP17A1) is an important target in the treatment of prostate cancer because it produces androgens required for tumour growth. The FDA has approved only one CYP17A1 inhibitor, abiraterone, which contains a steroidal scaffold similar to the endogenous CYP17A1 substrates. Abiraterone is structurally similar to the substrates of other cytochrome P450 enzymes involved in steroidogenesis, and interference can pose a liability in terms of side effects. Using non-steroidal scaffolds is expected to enable the design of compounds that interact more selectively with CYP17A1. Therefore, we combined a structure-based virtual screening approach with density functional theory (DFT) calculations to suggest non-steroidal compounds selective for CYP17A1. In vitro assays demonstrated that two such compounds selectively inhibited CYP17A1 17α-hydroxylase and 17,20-lyase activities with IC50 values in the nanomolar range, without affinity for the major drug-metabolizing CYP2D6 and CYP3A4 enzymes and CYP21A2, with the latter result confirmed in human H295R cells. PMID:27406023

EFFECTS OF SUBSCUTE EXPOSURE TO NANOMOLAR CONCENTRATIONS OF METHYLMERCURY ON VOLTAGE-GATES SODIUM AND CALCIUM CURRENTS IN PC12 CELLS.

EPA Science Inventory

Methylmercury (CH3Hg+) alters the function of voltage-gated Na+ and Ca2+ channels in neuronal preparations following acute, in vitro, exposure. Because the developing nervous system is particularly sensitive to CH3Hg+ neurotoxicity, effects on voltage-gated Na+ (INa) and Ca2+ (IC...

Nira acidity and antioxidant activity of Palm sugar in Sumowono Village

NASA Astrophysics Data System (ADS)

Winarni, Sri; Arifan, Fahmi; Wisnu Broto, RTD.; Fuadi, Ariza; Alviche, Lola

2018-05-01

The palm sugar not only has potential as natural sweetener but also has antioxidant. The purpose of this study was to analyze antioxidant and pH of the nira in palm sugar. The sample in this study was palm sugar from 6 different production sites. Test of antioxidant activity used DPPH method (1.1-diphenyl-2-picrylhydrazyl) with a wavelength of 517 nm. The value of absorbance solution was measured using spectrophotometry and the value of effective concentration (IC50) was counted. The pH test was measured using a pH meter. Pearson’s correlation test revealed r=-0.045 with significant value 0.932 (>0.005). There was no correlation between pH value and antioxidant activity of palm sugar. IC50 value of palm sugar in Sumowono village revealed that it had a strong antioxidant activity (50 μg/ml - 100 μg/ml) that is 74,73 μg/ml 83.94 μg/ml 82.31 μg/ml 83.94 μg/ml 86.10 μg/ml 82.13 μg/ml 89.17 μg/ml 89.71 μg/ml 89.17 μg/ml and 84.84 μg/ml). Lower IC50 values indicate higher antioxidant activity. Palm sugar with the best antioxidant activity came from the production sites which had IC50 values of 74.73 μg/ml. Potential antioxidants can be optimized by making improvements to the processing system.

Evaluation of in vitro anti-Leishmanial activity of some brown, green and red algae from the Persian Gulf.

PubMed

Fouladvand, M; Barazesh, A; Farokhzad, F; Malekizadeh, H; Sartavi, K

2011-06-01

Leishmaniasis is a protozoan parasitic disease which is transmitted by the female Phlebotomus sand fly and is prevalent in four continents.The first-choice treatment for the leishmaniasis is pentavalent antimonials, which are potentially toxic and often ineffective and use of them exhibit therapeutic failure. These pharmaceutical problems point towards the need to develop novel chemotherapeutic agents. Seaweeds are considered as source of bioactive metabolites characterized by a broad spectrum of biological activities. In this experimental study, cold and hot water crude extracts of four species of green, brown and red marine algae "Caulerpa sertularioides, Gracilaria corticata, Gracillaria salicornia and Sargassum oligocystum" collected along the Bushehr coast of the Persian Gulf (southwest of Iran), prepared and their in vitro activities against Leishmania major promastigote were evaluated by using the MTT assay test. The cold and hot water crude extracts of four algae species exhibited different anti-Leishmanial activities. The minimum inhibitory concentration of hot water extracts calculated as IC50 was as follows: Caulerpa sertularioides (IC50 < or =85 microg/ml), Gracilaria corticata (IC50 < or =38 microg/ml), Gracillaria salicornia (IC50 < or =46 microg/ml) and Sargassum oligocystum (IC(50)9 < or =78 microg/ml, while these values for cold water extracts were (IC50 >125 microg/ml) for Caulerpa Sertularioides (IC50 >65 microg/ml) for Gracilaria corticata (IC50 >74 microg/ml) for Gracilaria salicornia and (IC50 >105 microg/ml) for Sargassum oligocystum, IC50 values for reference drug (Amphotericin B) was (0.16-0.2 microg/ml). According to the results, inhibitory effects of the crude extracts from these four species algae specially hot water crude extracts from "Gracilaria corticata, Gracillaria salicornia and Sargassum oligocystum" are significant and in accordance with other studies that has been done on different algae species. So these results are sufficiently promising to be followed with further studies on isolation and characterization of pure compounds from these algae species as well as in vivo experiments, a work that is already under way in our laboratory.

Acetylcholinesterase and butyrylcholinesterase inhibitory activity of Pinus species essential oils and their constituents.

PubMed

Bonesi, Marco; Menichini, Federica; Tundis, Rosa; Loizzo, Monica R; Conforti, Filomena; Passalacqua, Nicodemo G; Statti, Giancarlo A; Menichini, Francesco

2010-10-01

This study aimed to investigate the acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity of the essential oils from Pinus nigra subsp. nigra, P. nigra var. calabrica, and P. heldreichii subsp. leucodermis. This activity is relevant to the treatment of Alzheimer's disease (AD), since cholinesterase drugs are currently the only drugs available to treat AD. P. heldreichii subsp. leucodermis exhibited the most promising activity, with IC(50) values of 51.1 and 80.6 microg/mL against AChE and BChE, respectively. An interesting activity against AChE was also observed with P. nigra subsp. nigra essential oil, with an IC(50) value of 94.4 microg/mL. Essential oils were analyzed by GC and GC-MS with the purpose of investigating their relationships with the observed activities. Among the identified constituents, terpinolene, beta-phellandrene, linalyl acetate, trans-caryophyllene, and terpinen-4-ol were tested. trans-Caryophyllene and terpinen-4-ol inhibited BChE with IC(50) values of 78.6 and 107.6 microg/mL, respectively. beta-Phellandrene was selective against AChE (IC(50) value of 120.2 microg/mL).

Screening of selected indigenous plants of Cambodia for antiplasmodial activity.

PubMed

Hout, Sotheara; Chea, Aun; Bun, Sok-Siya; Elias, Riad; Gasquet, Monique; Timon-David, Pierre; Balansard, Guy; Azas, Nadine

2006-08-11

The in vitro antiplasmodial activity of 117 aqueous, methanol and dichloromethane extracts derived from different parts of 28 indigenous wild plant species was studied. These plants are commonly used in Cambodian traditional medicine. The plant extracts were tested for in vitro activity against a chloroquine resistant Plasmodium falciparum strain (W2). Nine extracts were moderately active with IC(50) values ranging between 5 and 10 microg/ml, 17 extracts were active with IC(50) values ranging between 1 and 5 microg/ml. These 26 extracts derived from eight plants belong to six families. The most active extracts were dichloromethane and came from Stephania rotunda and Brucea javanica with IC(50) values of 1 microg/ml and a selectivity index > or = 25. It is interesting to note that some aqueous extracts were as active as dichloromethane extracts especially aqueous extracts of Stephania rotunda, Brucea javanica, Phyllanthus urinaria and Eurycoma longifolia with IC(50) values of < or = 4 microg/ml. These results are in agreement with statements of healers on traditional uses of these plants for the treatment of malaria and/or fever. In this study, we report the antiplasmodial potential activity of eight plant species from Cambodia. Among them four are tested for the first time.

Evaluation of Antileishmanial Activity of Selected Brazilian Plants and Identification of the Active Principles

PubMed Central

Filho, Valdir Cechinel; Meyre-Silva, Christiane; Niero, Rivaldo; Bolda Mariano, Luisa Nathália; Gomes do Nascimento, Fabiana; Vicente Farias, Ingrid; Gazoni, Vanessa Fátima; dos Santos Silva, Bruna; Giménez, Alberto; Gutierrez-Yapu, David; Salamanca, Efrain; Malheiros, Angela

2013-01-01

This study evaluated extracts, fractions, and isolated compounds from some selected Brazilian medicinal plants against strains of promastigotes of Leishmania amazonensis and L. brasiliensis in vitro. The cell viability was determined, comparing the results with reference standards. The dichloromethane fractions of the roots, stems, and leaves of Allamanda schottii showed IC50 values between 14.0 and 2.0 μg/mL. Plumericin was the main active compound, with IC50 of 0.3 and 0.04 μg/mL against the two species of Leishmania analyzed. The hexane extract of Eugenia umbelliflora fruits showed IC50 of 14.3 and 5.7 μg/mL against L. amazonensis and L. brasiliensis, respectively. The methanolic extracts of the seeds of Garcinia achachairu and guttiferone A presented IC50 values of 35.9 and 10.4 μg/mL, against L. amazonensis, respectively. The ethanolic extracts of the stem barks of Rapanea ferruginea and the isolated compound, myrsinoic acid B, presented activity against L. brasiliensis with IC50 of 24.1 and 6.1 μg/mL. Chloroform fraction of Solanum sisymbriifolium exhibited IC50 of 33.8 and 20.5 μg/mL, and cilistol A was the main active principle, with IC50 of 6.6 and 3.1 μg/mL against L. amazonensis and L. brasiliensis, respectively. It is concluded that the analyzed plants are promising as new and effective antiparasitic agents. PMID:23840252

Synthesis, Biological Activity, and Crystal Structure of Potent Nonnucleoside Inhibitors of HIV-1 Reverse Transcriptase That Retain Activity against Mutant Forms of the Enzyme†

PubMed Central

Morningstar, Marshall L.; Roth, Thomas; Farnsworth, David W.; Smith, Marilyn Kroeger; Watson, Karen; Buckheit, Robert W.; Das, Kalyan; Zhang, Wanyi; Arnold, Eddy; Julias, John G.; Hughes, Stephen H.; Michejda, Christopher J.

2010-01-01

In an ongoing effort to develop novel and potent nonnucleoside HIV-1 reverse transcriptase (RT) inhibitors that are effective against the wild type (WT) virus and clinically observed mutants, 1,2-bis-substituted benzimidazoles were synthesized and tested. Optimization of the N1 and C2 positions of benzimidazole led to the development of 1-(2,6-difluorobenzyl)-2-(2,6-difluorophenyl)-4-methylbenzimidazole (1) (IC50 = 0.2 μM, EC50 = 0.44 μM, and TC50 ≥ 100 against WT). This paper describes how substitution on the benzimidazole ring profoundly affects activity. Substituents at the benzimidazole C4 dramatically enhanced potency, while at C5 or C6 substituents were generally detrimental or neutral to activity, respectively. A 7-methyl analogue did not inhibit HIV-1 RT. Determination of the crystal structure of 1 bound to RT provided the basis for accurate modeling of additional analogues, which were synthesized and tested. Several derivatives were nanomolar inhibitors of wild-type virus and were effective against clinically relevant HIV-1 mutants. PMID:17663538

Phenolic, flavonoid contents, anticholinesterase and antioxidant evaluation of Iris germanica var; florentina.

PubMed

Ullah, Farhat; Ayaz, Muhammad; Sadiq, Abdul; Hussain, Abid; Ahmad, Sajjad; Imran, Muhammad; Zeb, Anwar

2016-06-01

This study was designed to investigate antioxidant and anticholinesterase potential of Iris germanica var; florentina. Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory potential of plant samples were investigated by Ellman's assay. Antioxidant activity was performed using DPPH, H2O2 and ABTS free radical scavenging assays. Total phenolics and flavonoids contents were expressed in mg GAE/g dry weight and mg RTE/g, respectively. In AChE inhibition assay, Ig.Fl, Ig.Sp and Ig.Cf fractions exhibited highest activity with IC50 values of < 0.1, 5.64 and 19 μg/mL, respectively. In BChE inhibitory assay, Ig.Fl, Ig.Sp, Ig.Cf and Ig.Cr were most active with IC50 of < 0.1, < 0.1, 31 and 78 μg/mL, respectively. In DPPH assay, Ig.Fl and Ig.Cf exhibited highest inhibition of free radicals, 80.52% (IC50 = 9 μg/mL) and 78.30% (IC50 = 8 μg/mL), respectively. In ABTS assay Ig.Cr, Ig.Cf, Ig.Fl and Ig.Sp exhibited IC50 values of < 0.1, 2, 2 and 3 μg/mL, respectively.

Biofunctional Properties of Enzymatic Squid Meat Hydrolysate

PubMed Central

Choi, Joon Hyuk; Kim, Kyung-Tae; Kim, Sang Moo

2015-01-01

Squid is one of the most important commercial fishes in the world and is mainly utilized or consumed as sliced raw fish or as processed products. The biofunctional activities of enzymatic squid meat hydrolysate were determined to develop value-added products. Enzymatic squid hydrolysate manufactured by Alcalase effectively quenched 1,1-diphenyl-2-picrylhydrazyl radical, hydroxyl radical, and hydrogen peroxide radical with IC50 values of 311, 3,410, and 111.5 μg/mL, respectively. Angiotensin I-converting enzyme inhibitory activity of squid hydrolysate was strong with an IC50 value of 145.1 μg/mL, while tyrosinase inhibitory activity with an IC50 value of 4.72 mg/mL was moderately low. Overall, squid meat hydrolysate can be used in food or cosmetic industries as a bioactive ingredient and possibly be used in the manufacture of seasoning, bread, noodle, or cosmetics. PMID:25866752

Direct led-fluorescence method for Mao-B inactivation in the treatment of Parkinson's

NASA Astrophysics Data System (ADS)

Castillo, Jimmy A.; Hung, Jannett; Rodriguez, M.; Bastidas, E.; Laboren, I.; Jaimes, A.

2004-10-01

A led-fluorescence spectroscopy method determinate the inhibitory effects of probe compounds on MAO-B activity is described. In this assay, we demonstrate the possibility of determinate the activity of MAO-B efficiently and rapidly without the use of reference substrate. Measuring variations in fluorescence intensity of MAO-B enzyme during the reaction with inhibitors, L-deprenyl and berberine IC50 and KI values were obtained. For L-deprenyl (IC50 = 0.017 μM and KI = 0.019 μM) and berberine (IC50 = 90 μM and KI = 47 μM) were in agreement to the values obtained with a standard method and literature reported.

Emetine inhibits Zika and Ebola virus infections through two molecular mechanisms: inhibiting viral replication and decreasing viral entry.

PubMed

Yang, Shu; Xu, Miao; Lee, Emily M; Gorshkov, Kirill; Shiryaev, Sergey A; He, Shihua; Sun, Wei; Cheng, Yu-Shan; Hu, Xin; Tharappel, Anil Mathew; Lu, Billy; Pinto, Antonella; Farhy, Chen; Huang, Chun-Teng; Zhang, Zirui; Zhu, Wenjun; Wu, Yuying; Zhou, Yi; Song, Guang; Zhu, Heng; Shamim, Khalida; Martínez-Romero, Carles; García-Sastre, Adolfo; Preston, Richard A; Jayaweera, Dushyantha T; Huang, Ruili; Huang, Wenwei; Xia, Menghang; Simeonov, Anton; Ming, Guoli; Qiu, Xiangguo; Terskikh, Alexey V; Tang, Hengli; Song, Hongjun; Zheng, Wei

2018-01-01

The re-emergence of Zika virus (ZIKV) and Ebola virus (EBOV) poses serious and continued threats to the global public health. Effective therapeutics for these maladies is an unmet need. Here, we show that emetine, an anti-protozoal agent, potently inhibits ZIKV and EBOV infection with a low nanomolar half maximal inhibitory concentration (IC 50 ) in vitro and potent activity in vivo. Two mechanisms of action for emetine are identified: the inhibition of ZIKV NS5 polymerase activity and disruption of lysosomal function. Emetine also inhibits EBOV entry. Cephaeline, a desmethyl analog of emetine, which may be better tolerated in patients than emetine, exhibits a similar efficacy against both ZIKV and EBOV infections. Hence, emetine and cephaeline offer pharmaceutical therapies against both ZIKV and EBOV infection.

PET and SPECT imaging of a radiolabeled minigastrin analogue conjugated with DOTA, NOTA, and NODAGA and labeled with (64)Cu, (68)Ga, and (111)In.

PubMed

Roosenburg, S; Laverman, P; Joosten, L; Cooper, M S; Kolenc-Peitl, P K; Foster, J M; Hudson, C; Leyton, J; Burnet, J; Oyen, W J G; Blower, P J; Mather, S J; Boerman, O C; Sosabowski, J K

2014-11-03

Cholecystokinin-2 (CCK-2) receptors, overexpressed in cancer types such as small cell lung cancers (SCLC) and medullary thyroid carcinomas (MTC), may serve as targets for peptide receptor radionuclide imaging. A variety of CCK and gastrin analogues has been developed, but a major drawback is metabolic instability or high kidney uptake. The minigastrin analogue PP-F11 has previously been shown to be a promising peptide for imaging of CCK-2 receptor positive tumors and was therefore further evaluated. The peptide was conjugated with one of the macrocyclic chelators DOTA, NOTA, or NODAGA. The peptide conjugates were then radiolabeled with either (68)Ga, (64)Cu, or (111)In. All (radio)labeled compounds were evaluated in vitro (IC50) and in vivo (biodistribution and PET/CT and SPECT/CT imaging). IC50 values were in the low nanomolar range for all compounds (0.79-1.51 nM). In the biodistribution studies, (68)Ga- and (111)In-labeled peptides showed higher tumor-to-background ratios than the (64)Cu-labeled compounds. All tested radiolabeled compounds clearly visualized the CCK2 receptor positive tumor in PET or SPECT imaging. The chelator did not seem to affect in vivo behavior of the peptide for (111)In- and (68)Ga-labeled peptides. In contrast, the biodistribution of the (64)Cu-labeled peptides showed high uptake in the liver and in other organs, most likely caused by high blood levels, probably due to dissociation of (64)Cu from the chelator and subsequent transchelation to proteins. Based on the present study, (68)Ga-DOTA-PP-F11 might be a promising radiopharmaceutical for PET/CT imaging of CCK2 receptor expressing tumors such as MTC and SCLC. Clinical studies are warranted to investigate the potential of this tracer.

Inhibition of lipoxygenases and cyclooxygenase-2 enzymes by extracts isolated from Bacopa monniera (L.) Wettst.

PubMed

Viji, V; Helen, A

2008-07-23

Bacopa monniera Linn is described in the Ayurvedic Materia Medica, as a therapeutically useful herb for the treatment of inflammation. In the current study, we investigated the anti-inflammatory activity of methanolic extract of Bacopa monniera (BME). For some experiments EtOAc and bacoside fractions were prepared from BME. The effect of these extracts in modulating key mediators of inflammation was evaluated. Carrageenan-induced rat paw edema, rat mononuclear cells and human whole blood assay were employed as in vivo and in vitro models. In carrageenan-induced rat paw edema, BME brought about 82% edema inhibition at a dose of 100mg/kg i.p. when compared to indomethacin (INDO) (3mg/kg) that showed 70% edema inhibition. BME also significantly inhibited 5-lipoxygenase (5-LOX), 15-LOX and cyclooxygenase-2 (COX-2) activities in rat monocytes in vivo. Among the fractions tested in vitro, EtOAc fraction possessed significant 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity with IC(50) value of 30 microg/ml compared to butylated hydroxyl toluene (IC(50) = 13 microg/ml). This fraction also exerted significant hydroxyl radical scavenging activity with IC(50) value of 25 microg/ml in comparison with quercetin (IC(50) = 5 microg/ml). Inhibitory effects of EtOAc and bacoside fractions on LOX and COX activities in Ca-A23187 stimulated rat mononuclear cells were also assessed. 5-LOX IC(50) values were 25 microg/ml for EtOAc, 68 microg/ml for bacosides and 2 microg/ml for nordihydroguaiaretic acid (NDGA) where as COX-2 IC(50) values were 1.32 microg/ml for EtOAc, 1.19 microg/ml for bacoside fraction and 0.23 microg/ml for indomethacin. EtOAc and bacoside fractions also brought about significant decrease in TNF-alpha release ex vivo. Bacopa monniera possesses anti-inflammatory activity through inhibition of COX and LOX and downregulation of TNF-alpha.

Acute toxicity of organophosphorus compounds in guinea pigs is sex- and age-dependent and cannot be solely accounted for by acetylcholinesterase inhibition.

PubMed

Fawcett, William P; Aracava, Yasco; Adler, Michael; Pereira, Edna F R; Albuquerque, Edson X

2009-02-01

This study was designed to test the hypothesis that the acute toxicity of the nerve agents S-[2-(diisopropylamino)ethyl]-O-ethyl methylphosphonothioate (VX), O-pinacolyl methylphosphonofluoridate (soman), and O-isopropyl methylphosphonofluoridate (sarin) in guinea pigs is age- and sex-dependent and cannot be fully accounted for by the irreversible inhibition of acetylcholinesterase (AChE). The subcutaneous doses of nerve agents needed to decrease 24-h survival of guinea pigs by 50% (LD(50) values) were estimated by probit analysis. In all animal groups, the rank order of LD(50) values was sarin > soman > VX. The LD(50) value of soman was not influenced by sex or age of the animals. In contrast, the LD(50) values of VX and sarin were lower in adult male than in age-matched female or younger guinea pigs. A colorimetric assay was used to determine the concentrations of nerve agents that inhibit in vitro 50% of AChE activity (IC(50) values) in guinea pig brain extracts, plasma, red blood cells, and whole blood. A positive correlation between LD(50) values and IC(50) values for AChE inhibition would support the hypothesis that AChE inhibition is a major determinant of the acute toxicity of the nerve agents. However, such a positive correlation was found only between LD(50) values and IC(50) values for AChE inhibition in brain extracts from neonatal and prepubertal guinea pigs. These results demonstrate for the first time that the lethal potencies of some nerve agents in guinea pigs are age- and sex-dependent. They also support the contention that mechanisms other than AChE inhibition contribute to the lethality of nerve agents.

Neopetrosiquinones A and B, Sesquiterpene Benzoquinones Isolated from the Deep-water Sponge Neopetrosia cf. proxima

PubMed Central

Winder, Priscilla L.; Baker, Heather L.; Linley, Patricia; Guzmán, Esther; Pomponi, Shirley A.; Diaz, M. Cristina; Reed, John K.; Wright, Amy E.

2011-01-01

Two new marine-derived sesquiterpene benzoquinones which we designate as neopetrosiquinone A (1) and B (2), have been isolated from a deep-water sponge of the family Petrosiidae. The structures were elucidated on the basis of their spectroscopic data. Compounds 1 and 2 inhibit the in vitro proliferation of the DLD-1 human colorectal adenocarcinoma cell line with IC50 values of 3.7 and 9.8 μM, respectively, and the PANC-1 human pancreatic carcinoma cell line with IC50 values of 6.1 and 13.8 μM, respectively. Neopetrosiquinone A (1) also inhibited the in vitro proliferation of the AsPC-1 human pancreatic carcinoma cell line with an IC50 value of 6.1 μM. The compounds are structurally related to alisiaquinone A, cyclozonarone and xestoquinone. PMID:22014756

Synthesis of novel fluorinated chalcones derived from 4‧-morpholinoacetophenone and their antiproliferative effects

NASA Astrophysics Data System (ADS)

Kurşun Aktar, Bedriye Seda; Oruç-Emre, Emine Elçin; Demirtaş, Ibrahim; Yaglioglu, Ayse Sahin; Guler, Caglar; Adem, Sevki; Karaküçük Iyidoğan, Ayşegül

2017-12-01

The fluorinated chalcones were synthesized by Claisen-Schmidt condensation between 4‧-morpholineacetophenone and various fluorinated benzaldehydes in the presence of NaOH in methanol. The synthesized compounds [1-7] were evaluated their antiproliferative activity against HeLa and C6 cell lines. Among them, compounds 4 and 5 were determined to have anticancer activity against HeLa cells line (IC50 values of 7.74 and 6.10 μg/mL, respectively). The anticancer activity results were shown that compounds 3, and 6 had inhibitory against C6 cells (IC50 values of 12.80 and 4.16 μg/mL, respectively). The compounds 1 and 2 had high antiproliferative activity with non-cytotoxicity. All of the new compounds, except for compound 4 showed inhibition against the human isozyme hCA I with IC50 in the range of 0.5-1,16 mM. Pyruvate kinase M2 (PKM2) was effectively inhibited by compound 4 with IC50 = 26 μM.

AVP-IC50 Pred: Multiple machine learning techniques-based prediction of peptide antiviral activity in terms of half maximal inhibitory concentration (IC50).

PubMed

Qureshi, Abid; Tandon, Himani; Kumar, Manoj

2015-11-01

Peptide-based antiviral therapeutics has gradually paved their way into mainstream drug discovery research. Experimental determination of peptides' antiviral activity as expressed by their IC50 values involves a lot of effort. Therefore, we have developed "AVP-IC50 Pred," a regression-based algorithm to predict the antiviral activity in terms of IC50 values (μM). A total of 759 non-redundant peptides from AVPdb and HIPdb were divided into a training/test set having 683 peptides (T(683)) and a validation set with 76 independent peptides (V(76)) for evaluation. We utilized important peptide sequence features like amino-acid compositions, binary profile of N8-C8 residues, physicochemical properties and their hybrids. Four different machine learning techniques (MLTs) namely Support vector machine, Random Forest, Instance-based classifier, and K-Star were employed. During 10-fold cross validation, we achieved maximum Pearson correlation coefficients (PCCs) of 0.66, 0.64, 0.56, 0.55, respectively, for the above MLTs using the best combination of feature sets. All the predictive models also performed well on the independent validation dataset and achieved maximum PCCs of 0.74, 0.68, 0.59, 0.57, respectively, on the best combination of feature sets. The AVP-IC50 Pred web server is anticipated to assist the researchers working on antiviral therapeutics by enabling them to computationally screen many compounds and focus experimental validation on the most promising set of peptides, thus reducing cost and time efforts. The server is available at http://crdd.osdd.net/servers/ic50avp. © 2015 Wiley Periodicals, Inc.

Antioxidant and Anti-Inflammatory Activities of Hydrolysates and Peptide Fractions Obtained by Enzymatic Hydrolysis of Selected Heat-Treated Edible Insects.

PubMed

Zielińska, Ewelina; Baraniak, Barbara; Karaś, Monika

2017-09-02

This study investigated the effect of heat treatment of edible insects on antioxidant and anti-inflammatory activities of peptides obtained by in vitro gastrointestinal digestion and absorption process thereof. The antioxidant potential of edible insect hydrolysates was determined as free radical-scavenging activity, ion chelating activity, and reducing power, whereas the anti-inflammatory activity was expressed as lipoxygenase and cyclooxygenase-2 inhibitory activity. The highest antiradical activity against DPPH • (2,2-diphenyl-1-picrylhydrazyl radical) was noted for a peptide fraction from baked cricket Gryllodes sigillatus hydrolysate (IC 50 value 10.9 µg/mL) and that against ABTS •+ (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical) was the highest for raw mealworm Tenebrio molitor hydrolysate (inhibitory concentration (IC 50 value) 5.3 µg/mL). The peptides obtained from boiled locust Schistocerca gregaria hydrolysate showed the highest Fe 2+ chelation ability (IC 50 value 2.57 µg/mL); furthermore, the highest reducing power was observed for raw G. sigillatus hydrolysate (0.771). The peptide fraction from a protein preparation from the locust S. gregaria exhibited the most significant lipoxygenase and cyclooxygenase-2 inhibitory activity (IC 50 value 3.13 µg/mL and 5.05 µg/mL, respectively).

Antioxidant and Anti-Inflammatory Activities of Hydrolysates and Peptide Fractions Obtained by Enzymatic Hydrolysis of Selected Heat-Treated Edible Insects

PubMed Central

Zielińska, Ewelina; Baraniak, Barbara; Karaś, Monika

2017-01-01

This study investigated the effect of heat treatment of edible insects on antioxidant and anti-inflammatory activities of peptides obtained by in vitro gastrointestinal digestion and absorption process thereof. The antioxidant potential of edible insect hydrolysates was determined as free radical-scavenging activity, ion chelating activity, and reducing power, whereas the anti-inflammatory activity was expressed as lipoxygenase and cyclooxygenase-2 inhibitory activity. The highest antiradical activity against DPPH• (2,2-diphenyl-1-picrylhydrazyl radical) was noted for a peptide fraction from baked cricket Gryllodes sigillatus hydrolysate (IC50 value 10.9 µg/mL) and that against ABTS•+ (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical) was the highest for raw mealworm Tenebrio molitor hydrolysate (inhibitory concentration (IC50 value) 5.3 µg/mL). The peptides obtained from boiled locust Schistocerca gregaria hydrolysate showed the highest Fe2+ chelation ability (IC50 value 2.57 µg/mL); furthermore, the highest reducing power was observed for raw G. sigillatus hydrolysate (0.771). The peptide fraction from a protein preparation from the locust S. gregaria exhibited the most significant lipoxygenase and cyclooxygenase-2 inhibitory activity (IC50 value 3.13 µg/mL and 5.05 µg/mL, respectively). PMID:28869499

Inhibitory Effects of Respiration Inhibitors on Aflatoxin Production

PubMed Central

Sakuda, Shohei; Prabowo, Diyan Febri; Takagi, Keiko; Shiomi, Kazuro; Mori, Mihoko; Ōmura, Satoshi; Nagasawa, Hiromichi

2014-01-01

Aflatoxin production inhibitors, which do not inhibit the growth of aflatoxigenic fungi, may be used to control aflatoxin without incurring a rapid spread of resistant strains. A respiration inhibitor that inhibits aflatoxin production was identified during a screening process for natural, aflatoxin-production inhibitors. This prompted us to evaluate respiration inhibitors as potential aflatoxin control agents. The inhibitory activities of four natural inhibitors, seven synthetic miticides, and nine synthetic fungicides were evaluated on aflatoxin production in Aspergillus parasiticus. All of the natural inhibitors (rotenone, siccanin, aptenin A5, and antimycin A) inhibited fungal aflatoxin production with IC50 values around 10 µM. Among the synthetic miticides, pyridaben, fluacrypyrim, and tolfenpyrad exhibited strong inhibitory activities with IC50 values less than 0.2 µM, whereas cyflumetofen did not show significant inhibitory activity. Of the synthetic fungicides, boscalid, pyribencarb, azoxystrobin, pyraclostrobin, and kresoxim-methyl demonstrated strong inhibitory activities, with IC50 values less than 0.5 µM. Fungal growth was not significantly affected by any of the inhibitors tested at concentrations used. There was no correlation observed between the targets of respiration inhibitors (complexes I, II, and III) and their IC50 values for aflatoxin-production inhibitory activity. This study suggests that respiration inhibitors, including commonly used pesticides, are useful for aflatoxin control. PMID:24674936

In vitro anti-plasmodial activity of some traditionally used medicinal plants against Plasmodium falciparum.

PubMed

Venkatesalu, V; Gopalan, N; Pillai, C R; Singh, Vineeta; Chandrasekaran, M; Senthilkumar, A; Chandramouli, N

2012-07-01

The anti-plasmodial activity of different solvent extracts of Adhatoda vasica (root), Caesalpinia pulcherrima (leaf), Carica papaya (pulp), Erythroxylum monogynum (leaf), Lantana camara (whole plant), Ocimum sanctum (root) and Phyllanthus niruri (whole plant) were studied against Plasmodium falciparum. Of the 35 extracts tested, seven extracts showed good anti-plasmodial activity. Methanol extract of C. pulcherrima showed the lowest IC50 value (10.96 μg/mL) followed by methanol extract of A. vasica (IC(50)=11.1 μg/mL), chloroform extract of O. sanctum (IC(50)=11.47 μg/mL), methanol extract of E. monogynum (IC(50)=12.23 μg/mL), acetone extract of C. pulcherrima (IC(50)=12.49 μg/mL), methanol extract of O. sanctum and acetone extract of A. vasica (IC(50)=14.04 μg/mL). The results of the present study justify the use of these medicinal plants in traditional practice, and also, a further study on the isolation of anti-plasmodial molecules from their active crude extracts is in progress.

Comparative Study of Erythrina indica Lam. (Febaceae) Leaves Extracts for Antioxidant Activity

PubMed Central

Sakat, SS; Juvekar, AR

2010-01-01

The present study was designed to investigate the antioxidant activity of aqueous and methanol extracts of Erythrina indica Lam leaves by in vitro methods viz. 1, 1-Diphenyl-2-Picrylhydrazyl, nitric oxide radical scavenging activity, and inhibition of lipid peroxidation by thiobarbituric acid reactive substances (TBARS) method on isolated rat liver tissues. Quantitative analysis of antioxidative components like total amount of phenolics, flavonoids, and flavonols were estimated using the spectrophotometric method. Linear regression analysis was used to calculate the IC50 value. Results showed that the aqueous and methanol extracts exhibited significant DPPH radicals scavenging activity with an IC50 value 342.59 ± 19.59, 283.24 ± 12.28 µg/mL respectively. Nitric oxide radicals were significantly scavenged by the aqueous and methanol extracts (IC50 = 250.12 ± 10.66; 328.29 ± 3.74 µg/mL). Lipid peroxidation induced by the Fe2+ was inhibited by the aqueous extract with low IC50 value (97.29 ± 2.05 µg/mL) as compared to methanol extract (IC50 = 283.74 ± 5.70 µg/mL). Both the extracts were exhibited similar quantities of total phenolics. Total flavonoids were found to be in higher quantities than total flavonols in aqueous extract as compared to methanol extract. From the results, it is concluded that the aqueous and methanol extracts of E. indica leaves possesses significant antioxidant activity that may be due to the presence of flavonoids and related polyphenolic compounds. PMID:21331194

Docking analysis targeted to the whole enzyme: an application to the prediction of inhibition of PTP1B by thiomorpholine and thiazolyl derivatives.

PubMed

Ganou, C A; Eleftheriou, P Th; Theodosis-Nobelos, P; Fesatidou, M; Geronikaki, A A; Lialiaris, T; Rekka, E A

2018-02-01

PTP1b is a protein tyrosine phosphatase involved in the inactivation of insulin receptor. Since inhibition of PTP1b may prolong the action of the receptor, PTP1b has become a drug target for the treatment of type II diabetes. In the present study, prediction of inhibition using docking analysis targeted specifically to the active or allosteric site was performed on 87 compounds structurally belonging to 10 different groups. Two groups, consisting of 15 thiomorpholine and 10 thiazolyl derivatives exhibiting the best prediction results, were selected for in vitro evaluation. All thiomorpholines showed inhibitory action (with IC 50 = 4-45 μΜ, Ki = 2-23 μM), while only three thiazolyl derivatives showed low inhibition (best IC 50 = 18 μΜ, Ki = 9 μΜ). However, free binding energy (E) was in accordance with the IC 50 values only for some compounds. Docking analysis targeted to the whole enzyme revealed that the compounds exhibiting IC 50 values higher than expected could bind to other peripheral sites with lower free energy, E o , than when bound to the active/allosteric site. A prediction factor, E- (Σ Eo × 0.16), which takes into account lower energy binding to peripheral sites, was proposed and was found to correlate well with the IC 50 values following an asymmetrical sigmoidal equation with r 2 = 0.9692.

Bond-based bilinear indices for computational discovery of novel trypanosomicidal drug-like compounds through virtual screening.

PubMed

Castillo-Garit, Juan Alberto; del Toro-Cortés, Oremia; Vega, Maria C; Rolón, Miriam; Rojas de Arias, Antonieta; Casañola-Martin, Gerardo M; Escario, José A; Gómez-Barrio, Alicia; Marrero-Ponce, Yovani; Torrens, Francisco; Abad, Concepción

2015-01-01

Two-dimensional bond-based bilinear indices and linear discriminant analysis are used in this report to perform a quantitative structure-activity relationship study to identify new trypanosomicidal compounds. A data set of 440 organic chemicals, 143 with antitrypanosomal activity and 297 having other clinical uses, is used to develop the theoretical models. Two discriminant models, computed using bond-based bilinear indices, are developed and both show accuracies higher than 86% for training and test sets. The stochastic model correctly indentifies nine out of eleven compounds of a set of organic chemicals obtained from our synthetic collaborators. The in vitro antitrypanosomal activity of this set against epimastigote forms of Trypanosoma cruzi is assayed. Both models show a good agreement between theoretical predictions and experimental results. Three compounds showed IC50 values for epimastigote elimination (AE) lower than 50 μM, while for the benznidazole the IC50 = 54.7 μM which was used as reference compound. The value of IC50 for cytotoxicity of these compounds is at least 5 times greater than their value of IC50 for AE. Finally, we can say that, the present algorithm constitutes a step forward in the search for efficient ways of discovering new antitrypanosomal compounds. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

A Novel Two-Step Hierarchical Quantitative Structure–Activity Relationship Modeling Work Flow for Predicting Acute Toxicity of Chemicals in Rodents

PubMed Central

Zhu, Hao; Ye, Lin; Richard, Ann; Golbraikh, Alexander; Wright, Fred A.; Rusyn, Ivan; Tropsha, Alexander

2009-01-01

Background Accurate prediction of in vivo toxicity from in vitro testing is a challenging problem. Large public–private consortia have been formed with the goal of improving chemical safety assessment by the means of high-throughput screening. Objective A wealth of available biological data requires new computational approaches to link chemical structure, in vitro data, and potential adverse health effects. Methods and results A database containing experimental cytotoxicity values for in vitro half-maximal inhibitory concentration (IC50) and in vivo rodent median lethal dose (LD50) for more than 300 chemicals was compiled by Zentralstelle zur Erfassung und Bewertung von Ersatz- und Ergaenzungsmethoden zum Tierversuch (ZEBET; National Center for Documentation and Evaluation of Alternative Methods to Animal Experiments). The application of conventional quantitative structure–activity relationship (QSAR) modeling approaches to predict mouse or rat acute LD50 values from chemical descriptors of ZEBET compounds yielded no statistically significant models. The analysis of these data showed no significant correlation between IC50 and LD50. However, a linear IC50 versus LD50 correlation could be established for a fraction of compounds. To capitalize on this observation, we developed a novel two-step modeling approach as follows. First, all chemicals are partitioned into two groups based on the relationship between IC50 and LD50 values: One group comprises compounds with linear IC50 versus LD50 relationships, and another group comprises the remaining compounds. Second, we built conventional binary classification QSAR models to predict the group affiliation based on chemical descriptors only. Third, we developed k-nearest neighbor continuous QSAR models for each subclass to predict LD50 values from chemical descriptors. All models were extensively validated using special protocols. Conclusions The novelty of this modeling approach is that it uses the relationships between in vivo and in vitro data only to inform the initial construction of the hierarchical two-step QSAR models. Models resulting from this approach employ chemical descriptors only for external prediction of acute rodent toxicity. PMID:19672406

A novel two-step hierarchical quantitative structure-activity relationship modeling work flow for predicting acute toxicity of chemicals in rodents.

PubMed

Zhu, Hao; Ye, Lin; Richard, Ann; Golbraikh, Alexander; Wright, Fred A; Rusyn, Ivan; Tropsha, Alexander

2009-08-01

Accurate prediction of in vivo toxicity from in vitro testing is a challenging problem. Large public-private consortia have been formed with the goal of improving chemical safety assessment by the means of high-throughput screening. A wealth of available biological data requires new computational approaches to link chemical structure, in vitro data, and potential adverse health effects. A database containing experimental cytotoxicity values for in vitro half-maximal inhibitory concentration (IC(50)) and in vivo rodent median lethal dose (LD(50)) for more than 300 chemicals was compiled by Zentralstelle zur Erfassung und Bewertung von Ersatz- und Ergaenzungsmethoden zum Tierversuch (ZEBET; National Center for Documentation and Evaluation of Alternative Methods to Animal Experiments). The application of conventional quantitative structure-activity relationship (QSAR) modeling approaches to predict mouse or rat acute LD(50) values from chemical descriptors of ZEBET compounds yielded no statistically significant models. The analysis of these data showed no significant correlation between IC(50) and LD(50). However, a linear IC(50) versus LD(50) correlation could be established for a fraction of compounds. To capitalize on this observation, we developed a novel two-step modeling approach as follows. First, all chemicals are partitioned into two groups based on the relationship between IC(50) and LD(50) values: One group comprises compounds with linear IC(50) versus LD(50) relationships, and another group comprises the remaining compounds. Second, we built conventional binary classification QSAR models to predict the group affiliation based on chemical descriptors only. Third, we developed k-nearest neighbor continuous QSAR models for each subclass to predict LD(50) values from chemical descriptors. All models were extensively validated using special protocols. The novelty of this modeling approach is that it uses the relationships between in vivo and in vitro data only to inform the initial construction of the hierarchical two-step QSAR models. Models resulting from this approach employ chemical descriptors only for external prediction of acute rodent toxicity.

Phytochemical and cytotoxic studies on the roots of Euphorbia fischeriana.

PubMed

Shi, Qun; Sun, Yi-Wei; Meng, Dali

2017-01-15

With the aim of supporting the folk applications of Euphorbia fischeriana, a phytochemical study was performed, which led to the discovery of 9 compounds, including three new ones (1-3) and six known ones (4-9). Their structures were determined by 1D, 2D NMR, and HRESIMS analysis. In the cytotoxic assays on Hep-3B cell line, 2 showed stronger inhibitory effects (IC 50 8.1μmol/L) than that of positive control, and 1, 8 and 9 also gave inhibitory effects in a certain degree with IC 50 values of 12.5, 12.0 and 18.7μmol/L, respectively. While on A549, the cytotoxic activities of 1 (IC 50 11.9μmol/L) and 8 (IC 50 9.4μmol/L) were superior to that of 5-Fu, and those of 4 and 9 were moderate with IC 50 values of 28.2 and 29.8μmol/L, respectively. In addition, both petroleum ether and dichloromethane extracts showed cytotoxic activities with different degree, while n-butanol extracts had no effect. The results clarified that the low-polarity fractions of E. fischeriana, including triterpenoids, abietane and tigliane-type diterpenoids might be the potential bioactive ingredients which will exert strong antitumor effects. Copyright © 2016 Elsevier Ltd. All rights reserved.

Administration of Menadione, Vitamin K3, Ameliorates Off-Target Effects on Corneal Epithelial Wound Healing Due to Receptor Tyrosine Kinase Inhibition.

PubMed

Rush, Jamie S; Bingaman, David P; Chaney, Paul G; Wax, Martin B; Ceresa, Brian P

2016-11-01

The antiangiogenic receptor tyrosine kinase inhibitor (RTKi), 3-[(4-bromo-2,6-difluorophenyl)methoxy]-5-[[[[4-(1-pyrrolidinyl) butyl] amino] carbonyl]amino]-4-isothiazolecarboxamide hydrochloride, targets VEGFR2 (half maximal inhibitory concentration [IC50] = 11 nM); however, off-target inhibition of epidermal growth factor receptor (EGFR) occurs at higher concentrations. (IC50 = 5.8 μM). This study was designed to determine the effect of topical RTKi treatment on EGF-mediated corneal epithelial wound healing and to develop new strategies to minimize off-target EGFR inhibition. In vitro corneal epithelial wound healing was measured in response to EGF using a transformed human cell line (hTCEpi cells). In vivo corneal wound healing was assessed using a murine model. In these complementary assays, wound healing was measured in the presence of varying RTKi concentrations. Immunoblot analysis was used to examine EGFR and VEGFR2 phosphorylation and the kinetics of EGFR degradation. An Alamar Blue assay measured VEGFR2-mediated cell biology. Receptor tyrosine kinase inhibitor exposure caused dose-dependent inhibition of EGFR-mediated corneal epithelial wound healing in vitro and in vivo. Nanomolar concentrations of menadione, a vitamin K3 analog, when coadministered with the RTKi, slowed EGFR degradation and ameliorated the inhibitory effects on epithelial wound healing both in vitro and in vivo. Menadione did not alter the RTKi's IC50 against VEGFR2 phosphorylation or its inhibition of VEGF-induced retinal endothelial cell proliferation. An antiangiogenic RTKi exhibited off-target effects on the corneal epithelium that can be minimized by menadione without deleteriously affecting its on-target VEGFR2 blockade. These data indicate that menadione has potential as a topical supplement for individuals suffering from perturbations in corneal epithelial homeostasis, especially as an untoward side effect of kinase inhibitors.

Antimicrobial and antileishmanial activities of diterpenoids isolated from the roots of Salvia deserta

USDA-ARS?s Scientific Manuscript database

Four diterpenes with biological activity were isolated from Salvia deserta roots. Taxodione was considered leishmanicidal, with IC50 value of 0.46 µg/mL against Leishimania donovani and also exhibited antifungal and antimicrobial activities. Ferruginol displayed the greatest activity (24-h IC50 1.29...

Interaction of Silymarin Flavonolignans with Organic Anion-Transporting Polypeptides

PubMed Central

Köck, Kathleen; Xie, Ying; Oberlies, Nicholas H.; Brouwer, Kim L. R.

2013-01-01

Organic anion-transporting polypeptides (OATPs) are multispecific transporters mediating the uptake of endogenous compounds and xenobiotics in tissues that are important for drug absorption and elimination, including the intestine and liver. Silymarin is a popular herbal supplement often used by patients with chronic liver disease; higher oral doses than those customarily used (140 mg three times/day) are being evaluated clinically. The present study examined the effect of silymarin flavonolignans on OATP1B1-, OATP1B3-, and OATP2B1-mediated transport in cell lines stably expressing these transporters and in human hepatocytes. In overexpressing cell lines, OATP1B1- and OATP1B3-mediated estradiol-17β-glucuronide uptake and OATP2B1-mediated estrone-3-sulfate uptake were inhibited by most of the silymarin flavonolignans investigated. OATP1B1-, OATP1B3-, and OATP2B1-mediated substrate transport was inhibited efficiently by silymarin (IC50 values of 1.3, 2.2 and 0.3 µM, respectively), silybin A (IC50 values of 9.7, 2.7 and 4.5 µM, respectively), silybin B (IC50 values of 8.5, 5.0 and 0.8 µM, respectively), and silychristin (IC50 values of 9.0, 36.4, and 3.6 µM, respectively). Furthermore, silymarin, silybin A, and silybin B (100 µM) significantly inhibited OATP-mediated estradiol-17β-glucuronide and rosuvastatin uptake into human hepatocytes. Calculation of the maximal unbound portal vein concentrations/IC50 values indicated a low risk for silymarin-drug interactions in hepatic uptake with a customary silymarin dose. The extent of silymarin-drug interactions depends on OATP isoform specificity and concentrations of flavonolignans at the site of drug transport. Higher than customary doses of silymarin, or formulations with improved bioavailability, may increase the risk of flavonolignan interactions with OATP substrates in patients. PMID:23401473

Antiproliferative Activity of Xanthones Isolated from Artocarpus obtusus

PubMed Central

Hashim, Najihah Mohd; Rahmani, Mawardi; Ee, Gwendoline Cheng Lian; Sukari, Mohd Aspollah; Yahayu, Maizatulakmal; Oktima, Winda; Ali, Abd Manaf; Go, Rusea

2012-01-01

An investigation of the chemical constituents in Artocarpus obtusus species led to the isolation of three new xanthones, pyranocycloartobiloxanthone A (1), dihydroartoindonesianin C (2), and pyranocycloartobiloxanthone B (3). The compounds were subjected to antiproliferative assay against human promyelocytic leukemia (HL60), human chronic myeloid leukemia (K562), and human estrogen receptor (ER+) positive breast cancer (MCF7) cell lines. Pyranocycloartobiloxanthone A (1) consistently showed strong cytotoxic activity against the three cell lines compared to the other two with IC50 values of 0.5, 2.0 and 5.0 μg/mL, respectively. Compound (1) was also observed to exert antiproliferative activity and apoptotic promoter towards HL60 and MCF7 cell lines at respective IC50 values. The compound (1) was not toxic towards normal cell lines human nontumorigenic breast cell line (MCF10A) and human peripheral blood mononuclear cells (PBMCs) with IC50 values of more than 30 μg/mL. PMID:21960741

Synthesis and discovery of highly functionalized mono- and bis-spiro-pyrrolidines as potent cholinesterase enzyme inhibitors.

PubMed

Kia, Yalda; Osman, Hasnah; Suresh Kumar, Raju; Basiri, Alireza; Murugaiyah, Vikneswaran

2014-04-01

Novel mono and bis spiropyrrolidine derivatives were synthesized via an efficient ionic liquid mediated, 1,3-dipolar cycloaddition methodology and evaluated in vitro for their AChE and BChE inhibitory activities in search for potent cholinesterase enzyme inhibitors. Most of the synthesized compounds displayed remarkable AChE inhibitory activities with IC50 values ranging from 1.68 to 21.85 μM, wherein compounds 8d and 8j were found to be most active inhibitors against AChE and BChE with IC50 values of 1.68 and 2.75 μM, respectively. Molecular modeling simulation on Torpedo californica AChE and human BChE receptors, showed good correlation between IC50 values and binding interaction template of the most active inhibitors docked into the active site of their relevant enzymes. Copyright © 2014 Elsevier Ltd. All rights reserved.

Neopetrosiquinones A and B, sesquiterpene benzoquinones isolated from the deep-water sponge Neopetrosia cf. proxima.

PubMed

Winder, Priscilla L; Baker, Heather L; Linley, Patricia; Guzmán, Esther A; Pomponi, Shirley A; Diaz, M Cristina; Reed, John K; Wright, Amy E

2011-11-15

Two new marine-derived sesquiterpene benzoquinones which we designate as neopetrosiquinones A (1) and B (2), have been isolated from a deep-water sponge of the family Petrosiidae. The structures were elucidated on the basis of their spectroscopic data. Compounds 1 and 2 inhibit the in vitro proliferation of the DLD-1 human colorectal adenocarcinoma cell line with IC(50) values of 3.7 and 9.8 μM, respectively, and the PANC-1 human pancreatic carcinoma cell line with IC(50) values of 6.1 and 13.8 μM, respectively. Neopetrosiquinone A (1) also inhibited the in vitro proliferation of the AsPC-1 human pancreatic carcinoma cell line with an IC(50) value of 6.1 μM. The compounds are structurally related to alisiaquinone A, cyclozonarone, and xestoquinone. Copyright © 2011 Elsevier Ltd. All rights reserved.

Inhibitory Effects of Commonly Used Herbal Extracts on UDP-Glucuronosyltransferase 1A4, 1A6, and 1A9 Enzyme Activities

PubMed Central

Mohamed, Mohamed-Eslam F.

2011-01-01

The aim of this study was to investigate the effect of commonly used botanicals on UDP-glucuronosyltransferase (UGT) 1A4, UGT1A6, and UGT1A9 activities in human liver microsomes. The extracts screened were black cohosh, cranberry, echinacea, garlic, ginkgo, ginseng, milk thistle, saw palmetto, and valerian in addition to the green tea catechin epigallocatechin gallate (EGCG). Formation of trifluoperazine glucuronide, serotonin glucuronide, and mycophenolic acid phenolic glucuronide was used as an index reaction for UGT1A4, UGT1A6, and UGT1A9 activities, respectively, in human liver microsomes. Inhibition potency was expressed as the concentration of the inhibitor at 50% activity (IC50) and the volume in which the dose could be diluted to generate an IC50-equivalent concentration [volume/dose index (VDI)]. Potential inhibitors were EGCG for UGT1A4, milk thistle for both UGT1A6 and UGT1A9, saw palmetto for UGT1A6, and cranberry for UGT1A9. EGCG inhibited UGT1A4 with an IC50 value of (mean ± S.E.) 33.8 ± 3.1 μg/ml. Milk thistle inhibited both UGT1A6 and UGT1A9 with IC50 values of 59.5 ± 3.6 and 33.6 ± 3.1 μg/ml, respectively. Saw palmetto and cranberry weakly inhibited UGT1A6 and UGT1A9, respectively, with IC50 values >100 μg/ml. For each inhibition, VDI was calculated to determine the potential of achieving IC50-equivalent concentrations in vivo. VDI values for inhibitors indicate a potential for inhibition of first-pass glucuronidation of UGT1A4, UGT1A6, and UGT1A9 substrates. These results highlight the possibility of herb-drug interactions through modulation of UGT enzyme activities. Further clinical studies are warranted to investigate the in vivo extent of the observed interactions. PMID:21632963

Discovery of novel, potent and low-toxicity angiotensin II receptor type 1 (AT1) blockers: Design, synthesis and biological evaluation of 6-substituted aminocarbonyl benzimidazoles with a chiral center.

PubMed

Han, Xiao-Feng; He, Xing; Wang, Miao; Xu, Di; Hao, Li-Ping; Liang, Ai-Hua; Zhang, Jun; Zhou, Zhi-Ming

2015-10-20

Novel angiotensin II receptor type 1 (AT1) blockers bearing 6-substituted carbamoyl benzimidazoles with a chiral center were designed and synthesized as the first step to develop new antihypertensive agents and understand their pharmacodynamic and pharmacokinetic properties. The newly synthesized compounds were tested for their potential ability to displace [(125)I] Sar(1) Ile(8)-Ang II, which was specifically bound to human AT1 receptor. Radioligand binding assays revealed nanomolar affinity in several compounds under study. The IC50 values of nine ligands were higher than those of Losartan. The screening of decreased blood pressure in spontaneous hypertensive rats displayed that compound 8S (IC₅₀ = 5.0 nM) was equipotent with Losartan, whereas compounds 13R (IC₅₀ = 7.3 nM), 14R (IC₅₀ = 6.3 nM), and 14S (IC₅₀ = 3.5 nM) were slightly ahead of Losartan, and the most significant activity was demonstrated by compound 8R (IC₅₀ = 1.1 nM). Candidate 8R was identified for its excellent efficacy in antihypertension and fairly low toxicity based on plasma analyses, toxicology studies, and chronic oral tests. Finally, compound 8R exhibited strong and multiple interactions with target active sites of the theoretical AT1 receptor model in docking study. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Inhibition of the recombinant cattle tick Rhipicephalus (Boophilus) annulatus glutathione S-transferase.

PubMed

Guneidy, Rasha A; Shahein, Yasser E; Abouelella, Amira M K; Zaki, Eman R; Hamed, Ragaa R

2014-09-01

Rhipicephalus (Boophilus) annulatus is a bloodsucking ectoparasite that causes severe production losses in the cattle industry. This study aims to evaluate the in vitro effects of tannic acid, hematin (GST inhibitors) and different plant extracts (rich in tannic acid) on the activity of the recombinant glutathione S-transferase enzyme of the Egyptian cattle tick R. annulatus (rRaGST), in order to confirm their ability to inhibit the parasitic essential detoxification enzyme glutathione S-transferase. Extraction with 70% ethanol of Hibiscus cannabinus (kenaf flowers), Punica granatum (red and white pomegranate peel), Musa acuminata (banana peel) (Musaceae), Medicago sativa (alfalfa seeds), Tamarindus indicus (seed) and Cuminum cyminum (cumin seed) were used to assess: (i) inhibitory capacities of rRaGST and (ii) their phenolic and flavonoid contents. Ethanol extraction of red pomegranate peel contained the highest content of phenolic compounds (29.95mg gallic acid/g dry tissue) compared to the other studied plant extracts. The highest inhibition activities of rRaGST were obtained with kenaf and red pomegranate peel (P. granatum) extracts with IC50 values of 0.123 and 0.136mg dry tissue/ml, respectively. Tannic acid was the more effective inhibitor of rRaGST with an IC50 value equal to 4.57μM compared to delphinidine-HCl (IC50=14.9±3.1μM). Gossypol had a weak inhibitory effect (IC50=43.7μM), and caffeic acid had almost no effect on tick GST activity. The IC50 values qualify ethacrynic acid as a potent inhibitor of rRaGST activity (IC50=0.034μM). Cibacron blue and hematin showed a considerable inhibition effect on rRaGST activity, and their IC50 values were 0.13μM and 7.5μM, respectively. The activity of rRaGST was highest for CDNB (30.2μmol/min/mg protein). The enzyme had also a peroxidatic activity (the specific activity equals 26.5μmol/min/mg protein). Both tannic acid and hematin inhibited rRaGST activity non-competitively with respect to GSH and competitively with respect to CDNB. While red pomegranate extracts inhibited rRaGST activity competitively with respect to GSH, uncompetitive inhibition was observed with respect to CDNB. Copyright © 2014 Elsevier GmbH. All rights reserved.

Inhibition of carboxylesterase 1 is associated with cholesteryl ester retention in human THP-1 monocyte/macrophages

PubMed Central

Crow, J. Allen; Middleton, Brandy L.; Borazjani, Abdolsamad; Hatfield, M. Jason; Potter, Philip M.; Ross, Matthew K.

2008-01-01

Cholesteryl esters are hydrolyzed by cholesteryl ester hydrolase (CEH) yielding free cholesterol for export from macrophages. Hence, CEH has an important regulatory role in macrophage reverse cholesterol transport (RCT). CEH and human carboxylesterase 1 (CES1) appear to be the same enzyme. CES1 is inhibited by oxons, the bioactive metabolites of organophosphate (OP) pesticides. Here, we show that CES1 protein is robustly expressed in human THP-1 monocytes/macrophages and its biochemical activity inhibited following treatment of cell lysates and intact cells with chlorpyrifos oxon, paraoxon, or methyl paraoxon (with nanomolar IC50 values) or after immunodepletion of CES1 protein. CES1 protein expression in cells is unaffected by 24-h paraoxon treatment, suggesting the reduced hydrolytic activity is due to covalent inhibition of CES1 by oxons and not down-regulation of expression. Most significantly, treatment of cholesterol-loaded macrophages with either paraoxon (a non-specific CES inhibitor) or benzil (a specific CES inhibitor) caused enhanced retention of intracellular cholesteryl esters and a “foamy” phenotype, consistent with reduced cholesteryl ester mobilization. Thus, exposure to OP pesticides, which results in the inhibition of CES1, may also inhibit macrophage RCT, an important process in the regression of atherosclerosis. PMID:18762277

Design, Synthesis, in Vitro, and in Vivo Anticancer and Antiangiogenic Activity of Novel 3-Arylaminobenzofuran Derivatives Targeting the Colchicine Site on Tubulin

PubMed Central

Romagnoli, Romeo; Baraldi, Pier Giovanni; Salvador, Maria Kimatrai; Prencipe, Filippo; Lopez-Cara, Carlota; Ortega, Santiago Schiaffino; Brancale, Andrea; Hamel, Ernest; Castagliuolo, Ignazio; Mitola, Stefania; Ronca, Roberto; Bortolozzi, Roberta; Porcù, Elena; Basso, Giuseppe; Viola, Giampietro

2015-01-01

A new series of compounds characterized by the presence of a 2-methoxy/ethoxycarbonyl group, combined with either no substituent or a methoxy group at each of the four possible positions of the benzene portion of the 3-(3′,4′,5′-trimethoxyanilino)benzo[b]furan skeleton, were evaluated for antiproliferative activity against cancer cells in culture and, for selected, highly active compounds, inhibition of tubulin polymerization, cell cycle effects, and in vivo potency. The greatest antiproliferative activity occurred with a methoxy group introduced at the C-6 position, the least with this substituent at C-4. Thus far, the most promising compound in this series was 2-methoxycarbonyl-3-(3′,4′,5′-trimethoxyanilino)-6-methoxybenzo-[b]furan (3g), which inhibited cancer cell growth at nanomolar concentrations (IC50 values of 0.3–27 nM), bound to the colchicine site of tubulin, induced apoptosis, and showed, both in vitro and in vivo, potent vascular disrupting properties derived from the effect of this compound on vascular endothelial cells. Compound 3g had in vivo antitumor activity in a murine model comparable to the activity obtained with combretastatin A-4 phosphate. PMID:25785605

Evaluation of the in vitro/in vivo potential of five berries (bilberry, blueberry, cranberry, elderberry, and raspberry ketones) commonly used as herbal supplements to inhibit uridine diphospho-glucuronosyltransferase.

PubMed

Choi, Eu Jin; Park, Jung Bae; Yoon, Kee Dong; Bae, Soo Kyung

2014-10-01

In this study, we evaluated inhibitory potentials of popularly-consumed berries (bilberry, blueberry, cranberry, elderberry, and raspberry ketones) as herbal supplements on UGT1A1, UGT1A4, UGT1A6, UGT1A9, and UGT2B7 in vitro. We also investigated the potential herb-drug interaction via UGT1A1 inhibition by blueberry in vivo. We demonstrated that these berries had only weak inhibitory effects on the five UGTs. Bilberry and elderberry had no apparent inhibitions. Blueberry weakly inhibited UGT1A1 with an IC50 value of 62.4±4.40 μg/mL and a Ki value of 53.1 μg/mL. Blueberry also weakly inhibited UGT2B7 with an IC50 value of 147±11.1 μg/mL. In addition, cranberry weakly inhibited UGT1A9 activity (IC50=458±49.7 μg/mL) and raspberry ketones weakly inhibited UGT2B7 activity (IC50=248±28.2 μg/mL). Among tested berries, blueberry showed the lowest IC50 value in the inhibition of UGT1A1 in vitro. However, the co-administration of blueberry had no effect on the pharmacokinetics of irinotecan and its active metabolite, SN-38, which was mainly eliminated via UGT1A1, in vivo. Our data suggests that these five berries are unlikely to cause clinically significant herb-drug interactions mediated via inhibition of UGT enzymes involved in drug metabolism. These findings should enable an understanding of herb-drug interactions for the safe use of popularly-consumed berries. Copyright © 2014 Elsevier Ltd. All rights reserved.

Copper (II) and zinc (II) complexes with flavanone derivatives: Identification of potential cholinesterase inhibitors by on-flow assays.

PubMed

Sarria, André Lucio Franceschini; Vilela, Adriana Ferreira Lopes; Frugeri, Bárbara Mammana; Fernandes, João Batista; Carlos, Rose Maria; da Silva, Maria Fátima das Graças Fernandes; Cass, Quezia Bezerra; Cardoso, Carmen Lúcia

2016-11-01

Metal chelates strongly influence the nature and magnitude of pharmacological activities in flavonoids. In recent years, studies have shown that a promising class of flavanone-metal ion complexes can act as selective cholinesterase inhibitors (ChEIs), which has led our group to synthesize a new series of flavanone derivatives (hesperidin, hesperetin, naringin, and naringenin) complexed to either copper (II) or zinc (II) and to evaluate their potential use as selective ChEIs. Most of the synthesized complexes exhibited greater inhibitory activity against acetylcholinesterase (AChE) than against butyrylcholinesterase (BChE). Nine of these complexes constituted potent, reversible, and selective ChEIs with inhibitory potency (IC 50 ) and inhibitory constant (K i ) ranging from 0.02 to 4.5μM. Copper complexes with flavanone-bipyridine derivatives afforded the best inhibitory activity against AChE and BChE. The complex Cu(naringin)(2,2'-bipyridine) (11) gave IC 50 and K i values of 0.012±0.002 and 0.07±0.01μM for huAChE, respectively, which were lower than the inhibitory values obtained for standard galanthamine (IC 50 =206±30.0 and K i =126±18.0μM). Evaluation of the inhibitory activity of this complex against butyrylcholinesterase from human serum (huBChE) gave IC 50 and K i values of 8.0±1.4 and 2.0±0.1μM, respectively. A Liquid Chromatography-Immobilized Capillary Enzyme Reactor by UV detection (LC-ICER-UV) assay allowed us to determine the IC 50 and K i values and the type of mechanism for the best inhibitors. Copyright © 2016 Elsevier Inc. All rights reserved.

Discovery of imidazopyridine derivatives as novel c-Met kinase inhibitors: Synthesis, SAR study, and biological activity.

PubMed

Yang, Yifei; Zhang, Yuan; Yang, LingYun; Zhao, Leilei; Si, Lianghui; Zhang, Huibin; Liu, Qingsong; Zhou, Jinpei

2017-02-01

Receptor tyrosine kinase c-Met acts as an alternative angiogenic pathway in the process and contents of cancers. A series of imidazopyridine derivatives were designed and synthesized according to the established docking studies as possible c-Met inhibitors. Most of these imidazopyridine derivatives displayed nanomolar potency against c-Met in both biochemical enzymatic screens and cellular pharmacology studies. Especially, compound 7g exhibited the most inhibitory activity against c-Met with IC 50 of 53.4nM and 253nM in enzymatic and cellular level, respectively. Following that, the compound 7g was docked into the protein of c-Met and the structure-activity relationship was analyzed in detail. These findings indicated that the novel imidazopyridine derivative compound 7g was a potential c-Met inhibitor deserving further investigation for cancer treatment. Copyright © 2016. Published by Elsevier Inc.

Structure-based design of novel quinoxaline-2-carboxylic acids and analogues as Pim-1 inhibitors.

PubMed

Oyallon, Bruno; Brachet-Botineau, Marie; Logé, Cédric; Bonnet, Pascal; Souab, Mohamed; Robert, Thomas; Ruchaud, Sandrine; Bach, Stéphane; Berthelot, Pascal; Gouilleux, Fabrice; Viaud-Massuard, Marie-Claude; Denevault-Sabourin, Caroline

2018-05-11

We identified a new series of quinoxaline-2-carboxylic acid derivatives, targeting the human proviral integration site for Moloney murine leukemia virus-1 (HsPim-1) kinase. Seventeen analogues were synthesized providing useful insight into structure-activity relationships studied. Docking studies realized in the ATP pocket of HsPim-1 are consistent with an unclassical binding mode of these inhibitors. The lead compound 1 was able to block HsPim-1 enzymatic activity at nanomolar concentrations (IC 50 of 74 nM), with a good selectivity profile against a panel of mammalian protein kinases. In vitro studies on the human chronic myeloid leukemia cell line KU812 showed an antitumor activity at micromolar concentrations. As a result, compound 1 represents a promising lead for the design of novel anticancer targeted therapies. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Tacripyrines, the first tacrine-dihydropyridine hybrids, as multitarget-directed ligands for the treatment of Alzheimer's disease.

PubMed

Marco-Contelles, José; León, Rafael; de los Ríos, Cristóbal; Samadi, Abdelouahid; Bartolini, Manuela; Andrisano, Vincenza; Huertas, Oscar; Barril, Xavier; Luque, F Javier; Rodríguez-Franco, María I; López, Beatriz; López, Manuela G; García, Antonio G; Carreiras, María do Carmo; Villarroya, Mercedes

2009-05-14

Tacripyrines (1-14) have been designed by combining an AChE inhibitor (tacrine) with a calcium antagonist such as nimodipine and are targeted to develop a multitarget therapeutic strategy to confront AD. Tacripyrines are selective and potent AChE inhibitors in the nanomolar range. The mixed type inhibition of hAChE activity of compound 11 (IC(50) 105 +/- 15 nM) is associated to a 30.7 +/- 8.6% inhibition of the proaggregating action of AChE on the Abeta and a moderate inhibition of Abeta self-aggregation (34.9 +/- 5.4%). Molecular modeling indicates that binding of compound 11 to the AChE PAS mainly involves the (R)-11 enantiomer, which also agrees with the noncompetitive inhibition mechanism exhibited by p-methoxytacripyrine 11. Tacripyrines are neuroprotective agents, show moderate Ca(2+) channel blocking effect, and cross the blood-brain barrier, emerging as lead candidates for treating AD.

Discovery of potent inhibitors of soluble epoxide hydrolase by combinatorial library design and structure-based virtual screening.

PubMed

Xing, Li; McDonald, Joseph J; Kolodziej, Steve A; Kurumbail, Ravi G; Williams, Jennifer M; Warren, Chad J; O'Neal, Janet M; Skepner, Jill E; Roberds, Steven L

2011-03-10

Structure-based virtual screening was applied to design combinatorial libraries to discover novel and potent soluble epoxide hydrolase (sEH) inhibitors. X-ray crystal structures revealed unique interactions for a benzoxazole template in addition to the conserved hydrogen bonds with the catalytic machinery of sEH. By exploitation of the favorable binding elements, two iterations of library design based on amide coupling were employed, guided principally by the docking results of the enumerated virtual products. Biological screening of the libraries demonstrated as high as 90% hit rate, of which over two dozen compounds were single digit nanomolar sEH inhibitors by IC(50) determination. In total the library design and synthesis produced more than 300 submicromolar sEH inhibitors. In cellular systems consistent activities were demonstrated with biochemical measurements. The SAR understanding of the benzoxazole template provides valuable insights into discovery of novel sEH inhibitors as therapeutic agents.

Comparing myotoxic effects of squalene synthase inhibitor, T-91485, and 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors in human myocytes.

PubMed

Nishimoto, Tomoyuki; Tozawa, Ryuichi; Amano, Yuichiro; Wada, Takeo; Imura, Yoshimi; Sugiyama, Yasuo

2003-12-01

TAK-475 is a squalene synthase inhibitor, rapidly metabolized to T-91485 in vivo. We investigated the myotoxicities of T-91485 and 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors in a human rhabdomyosarcoma cell line, RD, and in human skeletal myocytes. In differentiated RD cells, T-91485, atorvastatin (ATV) and simvastatin acid (SIM) inhibited cholesterol biosynthesis, with IC(50) values of 36, 2.8 and 3.8 nM, respectively. ATV and SIM decreased the intracellular ATP content, with IC(25) values (concentrations giving a 25% decrease in intracellular ATP content) of 0.61 and 0.44 microM, respectively. Although T-91485 potently inhibited cholesterol synthesis in RD cells, the IC(25) value exceeded 100 microM. In human skeletal myocytes, T-91485, ATV and SIM concentration-dependently inhibited cholesterol biosynthesis, with IC(50) values of 45, 8.6 and 8.4 nM, respectively. ATV and SIM decreased intracellular ATP content, with IC(25) values of 2.1 and 0.72 microM, respectively. Although T-91485 potently inhibited cholesterol synthesis, the IC(25) value exceeded 100 microM. Myotoxicity induced by ATV was prevented by mevalonate or geranylgeranyl-PP, but not by squalene in skeletal cells. Furthermore, T-91485 attenuated the myotoxicity of ATV. These findings suggest that TAK-475 and T-91485 may not only be far from myotoxic, they may also decrease statin-induced myotoxicity in lipid-lowering therapy.

Naphthoquinones from the leaves of Rhinacanthus nasutus having acetylcholinesterase inhibitory and cytotoxic activities.

PubMed

Boonyaketgoson, Sirada; Rukachaisirikul, Vatcharin; Phongpaichit, Souwalak; Trisuwan, Kongkiat

2018-01-01

Four new naphthoquinones (1-4), named rhinacanthins S (1), T (2), U (3) and V (4), together with 13 known naphthoquinones were isolated from the leaf extract of Rhinacanthus nasutus. The structures of isolated compounds were elucidated by spectroscopic methods, especially 1D and 2D NMR spectroscopy and mass spectrometry. Rhinacanthin S (1) exhibited acetylcholinesterase inhibition activity with a % inhibition value of 48.04±3.25. The known rhinacanthin A (5) showed cytotoxicity against a MCF-7 cell line with an IC 50 value of 8.79μM, while rhinacanthin N (15) was active against the NCI-H187 cell line with an IC 50 =2.24μM and Vero cells (IC 50 =3.00μM). Copyright © 2017 Elsevier B.V. All rights reserved.

Cancer targeting potential of folate targeted nanocarrier under comparative influence of tretinoin and dexamethasone.

PubMed

Dhakad, Raghvendra Singh; Tekade, Rakesh Kumar; Jain, Narendra Kumar

2013-08-01

The objective of this investigation was aimed to explore the cancer targeting potential of folate conjugated dendrimer (polypropylene imine, PPI) under strategic influence of folate receptor up-regulators (all trans Retinoic acid, ATRA and Dexamethasone, DEXA). The folate conjugated dendrimer nanoconjugate (FPPI) was synthesized and characterized by FTIR, and (1)H-NMR spectroscopy. The cell line studies investigations were performed on MCF-7 cells. ATRA and DEXA caused 2.17 and 1.65 folds selective up-regulation of folate receptor respectively, when compared with untreated control, after 48 h of pretreatment. ATRA caused 50.47±2.11% more up regulation of folate receptor, than DEXA treated cell. Both up regulators showed a lag phase of 12 h in up-regulating the folate receptors. After 48 h, the IC50 values of naked docetaxel (DTX) and DTX loaded dendrimer (PPI-DTX) were found to be 678.93±11.99 nM and 663.51±15.23 nM, respectively, while DTX loaded folate-anchored dendrimer (FPPI-DTX) showed a selectively lowered IC50 value of 468.56±20.86 nM. FPPI-DTX further showed a significant reduction in IC50 value in ATRA and DEXA pretreated cells, wherein IC50 values of 184.21 nM and 290.40±14.05 nM, respectively were observed. The study also concludes ATRA to be a superior receptor up-regulator as well as promoter of folate based targeting compared to DEXA.

Antimicrobial and antiprotozoal activities of secondary metabolites from the fungus Eurotium repens

PubMed Central

Gao, Jiangtao; Radwan, Mohamed M.; León, Francisco; Wang, Xiaoning; Jacob, Melissa R.; Tekwani, Babu L.; Khan, Shabana I.; Lupien, Shari; Hill, Robert A.; Dugan, Frank M.; Cutler, Horace G.

2011-01-01

In this study, we examined in vitro antibacterial, antifungal, antimalarial, and antileishmanial activities of secondary metabolites (1–8) isolated from the fungus Eurotium repens. All compounds showed mild to moderate antibacterial or antifungal or both activities except 7. The activity of compound 6 was the best of the group tested. The in vitro antimalarial evaluation of these compounds revealed that compounds 1–3, 5, and 6 showed antimalarial activities against both chloroquine-sensitive and chloroquine-resistant strains of Plasmodium falciparum with IC50 values in the range of 1.1–3.0 μg/ml without showing any cytotoxicity to the mammalian cells. Compound 5 displayed the highest antimalarial activity. Antileishmanial activity against Leishmania donovani promastigotes was observed for compounds 1–6 with IC50 values ranging from 6.2 to 23 μg/ml. Antileishmanial activity of compounds 5 and 6 (IC50 values of 7.5 and 6.2 μg/ml, respectively) was more potent than 1–4 (IC50 values ranging from 19–23 μg/ml). Compounds 7 and 8 did not show any antiprotozoal effect. Preliminary structure and activity relationship studies indicated that antibacterial, antifungal, antimalarial, and antileishmanial activities associated with phenol derivates (1–6) seem to be dependent on the number of double bonds in the side chain, which would be important for lead optimization in the future. PMID:23024574

Cytotoxic constituents of propolis from Myanmar and their structure-activity relationship.

PubMed

Li, Feng; Awale, Suresh; Tezuka, Yasuhiro; Kadota, Shigetoshi

2009-12-01

Thirteen cycloartane-type tritepenes (1-13) and four prenylated flavanones (14-17) isolated from propolis collected in Myanmar, were evaluated for their cytotoxic activity against a panel of six different cancer cell lines; three murine cancer cell lines (colon 26-L5 carcinoma, B16-BL6 melanoma, and Lewis lung carcinoma) and three human cancer cell lines (lung A549 adenocarcinoma, cervix HeLa adenocarcinoma and HT-1080 fibrosarcoma). Among them, a cycloartane-type triterpene, 3alpha,27-dihydroxycycloart-24E-en-26-oic acid (3), showed the most potent cytotoxicity against B16-BL6 cells with an IC(50) value of 5.91 microM, comparable to those of positive controls, doxorubicin (IC(50), 5.66 microM) and 5-fluorouracil (IC(50), 4.88 microM). In addition, (2S)-5,7-dihydroxy-4'-methoxy-8,3'-diprenylflavanone (14) exhibited strong cytotoxicity against all the tested cancer cell lines with the IC(50) values ranging from 14.0 to 26.4 microM. Based on the observed results, the structure-activity relationships are discussed.

Structure-activity relationships and docking studies of synthetic 2-arylindole derivatives determined with aromatase and quinone reductase 1.

PubMed

Prior, Allan M; Yu, Xufen; Park, Eun-Jung; Kondratyuk, Tamara P; Lin, Yan; Pezzuto, John M; Sun, Dianqing

2017-12-15

In our ongoing effort of discovering anticancer and chemopreventive agents, a series of 2-arylindole derivatives were synthesized and evaluated toward aromatase and quinone reductase 1 (QR1). Biological evaluation revealed that several compounds (e.g., 2d, IC 50  = 1.61 μM; 21, IC 50  = 3.05 μM; and 27, IC 50  = 3.34 μM) showed aromatase inhibitory activity with half maximal inhibitory concentration (IC 50 ) values in the low micromolar concentrations. With regard to the QR1 induction activity, 11 exhibited the highest QR1 induction ratio (IR) with a low concentration to double activity (CD) value (IR = 8.34, CD = 2.75 μM), while 7 showed the most potent CD value of 1.12 μM. A dual acting compound 24 showed aromatase inhibition (IC 50  = 9.00 μM) as well as QR1 induction (CD = 5.76 μM) activities. Computational docking studies using CDOCKER (Discovery Studio 3.5) provided insight in regard to the potential binding modes of 2-arylindoles within the aromatase active site. Predominantly, the 2-arylindoles preferred binding with the 2-aryl group toward a small hydrophobic pocket within the active site. The C-5 electron withdrawing group on indole was predicted to have an important role and formed a hydrogen bond with Ser478 (OH). Alternatively, meta-pyridyl analogs may orient with the pyridyl 3'-nitrogen coordinating with the heme group. Copyright © 2017 Elsevier Ltd. All rights reserved.

Anti-Inflammatory Components of the Starfish Astropecten polyacanthus

PubMed Central

Thao, Nguyen Phuong; Cuong, Nguyen Xuan; Luyen, Bui Thi Thuy; Quang, Tran Hong; Hanh, Tran Thi Hong; Kim, Sohyun; Koh, Young-Sang; Nam, Nguyen Hoai; Kiem, Phan Van; Minh, Chau Van; Kim, Young Ho

2013-01-01

Inflammation is important in biomedical research, because it plays a key role in inflammatory diseases including rheumatoid arthritis and other forms of arthritis, diabetes, heart disease, irritable bowel syndrome, Alzheimer’s disease, Parkinson’s disease, allergies, asthma, and even cancer. In the present study, we describe the inhibitory effect of crude extracts and steroids isolated from the starfish Astropecten polyacanthus on pro-inflammatory cytokine (Interleukin-12 (IL-12) p40, interleukin-6 (IL-6), and tumor necrosis factor α (TNF-α)) production in lipopolysaccharide (LPS)-stimulated bone marrow-derived dendritic cells (BMDCs). Among those tested, compounds 5 and 7 showed potent inhibitory effects on the production of all three pro-inflammatory cytokines with IC50 values ranging from 1.82 ± 0.11 to 7.00 ± 0.16 μM. Potent inhibitory activities were also observed for compound 1 on the production of IL-12 p40 and IL-6 with values of 3.96 ± 0.12 and 4.07 ± 0.13 μM, respectively, and for compounds 3 and 4 on the production of IL-12 p40 with values of 6.55 ± 0.18 and 5.06 ± 0.16 μM, respectively. Moreover, compounds 2 (IC50 = 34.86 ± 0.31 μM) and 6 (IC50 = 79.05 ± 2.05 μM) exhibited moderate inhibitory effects on the production of IL-12 p40, whereas compounds 3 (IC50 = 22.80 ± 0.21 μM) and 4 (IC50 = 16.73 ± 0.25 μM) moderately inhibited the production of TNF-α and IL-6, respectively. PMID:23945602

Umbelliprenin is cytotoxic against QU-DB large cell lung cancer cell line but anti-proliferative against A549 adenocarcinoma cells

PubMed Central

2012-01-01

Background Umbelliprenin is a natural compound, belonging to the class of sesquiterpene coumarins. Recently, umbelliprenin has attracted the researchers' attention for its antitumor activities against skin tumors. Its effect on lung cancer is largely unknown. The aim of our study was to investigate the effects of this natural compound, which is expected to have low adverse effects, on lung cancer. Methods The QU-DB large cell and A549 adenocarcinoma lung cancer cell lines were treated with umbelliprenin. IC50 values were estimated using methyl thiazolely diphenyl-tetrazolium bromide (MTT) assay, in which a decrease in MTT reduction can occur as a result of cell death or cell proliferation inhibition. To quantify the rate of cell death at IC50 values, flow cytometry using Annexin V-FITC (for apoptotic cells), and propidium iodide (for necrotic cells) dyes were employed. Results Data from three independent MTT experiments in triplicate revealed that IC50 values for QU-DB and A549 were 47 ± 5.3 μM and 52 ± 1.97 μM, respectively. Annexin V/PI staining demonstrated that umbelliprenin treatment at IC50 induced 50% cell death in QU-DB cells, but produced no significant death in A549 cells until increasing the umbelliprenin concentration to IC80. The pattern of cell death was predominantly apoptosis in both cell lines. When peripheral blood mononuclear cells were treated with 50 μM and less concentrations of umbelliprenin, no suppressive effect was observed. Conclusions We found cytotoxic/anti-proliferative effects of umbelliprenin against two different types of lung cancer cell lines. PMID:23351548

Endothelin-1 inactivating peptidase in the human kidney and urine.

PubMed

Janas, J; Sitkiewicz, D; Januszewicz, A; Szczesniak, C; Grenda, R; Janas, R M

2000-04-01

Recently, an apparently novel, specific endothelin-1 inactivating metalloendopeptidase (ET-1 peptidase) has been isolated from the rat kidney. In this study we attempted to determine whether the same or a similar peptidase is present in the human kidney, and whether the enzyme is excreted into the urine. The urinary ET-1 peptidase could serve as an indirect index of the renal endothelin system, both in physiology and pathophysiology. Kidney specimens were obtained from part of nephrectomized kidneys unaffected by any neoplastic process from six adult patients. The enzyme was purified using differential centrifugation, detergent solubilization of the membrane proteins, ultrafiltration and nondenaturing gel electrophoresis. The enzyme activity assays were performed at pH 5.5 and 37 degrees C in the presence of increasing concentrations of unlabelled peptides and inhibitors using a fixed amount of [125I]ET-1 as substrate. The degradation extent was quantified with trichloroacetic acid precipitation and high performance liquid chromatography. The degrading activity of ET-1 was determined in urine samples from adult patients with hypertension, children with chronic renal failure and those with stable renal allograft ET-1 peptidase from the human kidney displays characteristics close to that of the rat ET-1 peptidase we have recently described (J. Hypertens 1994; 12:1155-1162). The enzyme, a membrane-bound metalloendopeptidase, exhibits low electro- phoretical mobility on nondenaturing gel (Rf 0.08); it is an apparently heterologous structure comprising three enzymatically inactive subunits, it has a pH optimum at 5.5, a nanomolar range affinity to the ET-1 (KM 180 nmol/l) that is hydrolysed to two main degradation products, and a 10-100-fold lower affinity to big ET-1 (KM 11.5 micromol/l), endothelin 11 21 fragment (KM 15.3 micromol/l), endothelin antagonist Trp-Leu-Asp-Ile-Ile-Trp (KM 3.1 micromol/I), gastrin (KM 2.2 micromol/l) and cholecystokinin (KM 4.0 micromol/l). Substance P, neuropeptide Y, atrial natriuretic peptide, bradykinin, angiotensin II and enkephalin were poor substrates for the enzyme. The most powerful inhibitors of the ET-1 peptidase included thiorphan (IC50 0.28 nmol/l), phosphoramidon (IC50 0.55 nmol/l), phenanthroline (IC50 11.5 micromol/l), cyclosporin (IC50 400 micromol/l), phosphate (IC50 1.2 mmol/l), citrate (IC50 0.6 mmol/l) and aniline naphthalene sulphonic acid (IC50 0.25 mmol/l). Our data suggest that three ET-1 degrading peptidases with optimal activity at pH 4.5, 5.5 and 7.0, respectively, are excreted into the urine. The enzyme with a pH optimum 4.5 is of lysosomal origin whereas the two other enzymes correspond by their pH optima to the renal ET-1 peptidase and neutral endopeptidase. We have found statistically significant increases (P < 0.001) in the activity of both lysosomal and ET-1 peptidase in the urine in patients with hypertension and in children with chronic renal failure compared with healthy subjects or children with stable renal allograft Human kidney contains an acidic, highly specific endothelin-1 inactivating metalloendopeptidase that may have a key role in the regulation of concentrations of renal and circulating endothelins. The enzyme is excreted into the urine where its activity seems to be increased in patients with hypertension and chronic renal failure; it may potentially serve as an indirect index of the renal endothelin system.

[111In-DOTA]LTT-SS28, a first pansomatostatin radioligand for in vivo targeting of somatostatin receptor-positive tumors.

PubMed

Maina, Theodosia; Cescato, Renzo; Waser, Beatrice; Tatsi, Aikaterini; Kaloudi, Aikaterini; Krenning, Eric P; de Jong, Marion; Nock, Berthold A; Reubi, Jean Claude

2014-08-14

Radiolabeled pansomatostatin-like analogues are expected to enhance the diagnostic sensitivity and to expand the clinical indications of currently applied sst2-specific radioligands. In this study, we present the somatostatin mimic [DOTA]LTT-SS28 {[(DOTA)Ser1,Leu8,D-Trp22,Tyr25]SS28} and its 111In radioligand. [DOTA]LTT-SS28 exhibited a pansomatostatin-like profile binding with high affinity to all five hsst1-hsst5 subtypes (IC50 values in the lower nanomolar range). Furthermore, [DOTA]LTT-SS28 behaved as an agonist at hsst2, hsst3, and hsst5, efficiently stimulating internalization of the three receptor subtypes. Radioligand [111In-DOTA]LTT-SS28 showed good stability in the mouse bloodstream. It displayed strong and specific uptake in AR42J tumors 4 h postinjection (9.3±1.6% ID/g vs 0.3±0.0% ID/g during sst2 blockade) in mice. Significant and specific uptake was also observed in HEK293-hsst2-, HEK293-hsst3-, and HEK293-hsst5-expressing tumors (4.43±1.5, 4.88±1.1, and <3% ID/g, respectively, with values of <0.5% ID/g during receptor blockade). In conclusion, the somatostatin mimic [111In-DOTA]LTT-SS28 specifically localizes in sst2-, sst3-, and sst5-expressing xenografts in mice showing promise for multi-sst1-sst5 targeted tumor imaging.

Synthesis of 2',4-dihydroxy-3-methoxychalcone and 2',4',4-trihydroxy-3-methoxychalcone as a candidate anticancer against cervical (WiDr), colon (HeLa), and breast (T47d) cancer cell lines in vitro

NASA Astrophysics Data System (ADS)

Matsjeh, Sabirin; Swasono, Respati Tri; Anwar, Chairil; Solikhah, Eti Nurwening; Lestari, Endang

2017-03-01

The compound 2',4-dihydroxy-3-methoxychalcone and 2',4',4-trihydroxy-3-methoxychalcone have been synthesized through Claisen-Schmidt reaction from 2-hydroxyacetophenone and 2,4-dihydroxyacetophenone with 4-hydroxy-3-methoxy benzaldehida (vanillin) in aqueous KOH 40% and KSF montmorillonite as catalyst in methanol. All these products were characterized by FT-IR, TLC Scanner, GC-MS, MS-Direct, and 1H-NMR and 13C-NMR spectrometer. Both of these compounds were tested citotoxycity activity as an anticancer against cervical, colon, and breast cancer cells (Hela, WiDr, and T47D cell lines) using MTT assay in vitro. Dose series given test solution concentration on Hela, WiDr, and T47D cells started from 6,25; 25; 50 and 100 µg/mL with incubation treatment for 24 hours. The result of study showed that the 2',4-dihydroxy-3-methoxychalcone as bright yellow crystal with the melting point of 114-115 °C and the yield of 13.77% and the 2',4',4-trihydroxy-3-methoxychalcone as bright yellow crystals with the melting point of 195-197 °C and the yield of 6%. Other 2',4-dihydroxy-3-methoxychalcone and 2',4',4-trihydroxy-3-methoxychalcone also exhibited cytotoxic activity against the cancer cell lines, with the 2',4',4-trihydroxy-3-methoxychalcone showed greater activities than the 2',4-dihydroxy-3-methoxychalcone in WiDr cell lines. The 2',4-dihydroxy-3-methoxychalcone and 2',4',4-trihydroxy-3-methoxychalcone exhibited strong anticancer activities with IC50 value below 20 µg/mL. The activity of 2',4',4-trihydroxy-3-methoxychalcone showed the most active against Hela and WiDr cell lines with IC50 value 8.53 and 2.66 µg/mL respectively, than T47D cell lines with IC50 value 24.61 µg/mL. The test results cytotoxic of 2',4-dihydroxy-3-methoxychalcone showed the most active against Hela and WiDr cell lines with IC50 value 12.80, 19.57 µg/mL than T47D cell lines with IC50 value of 20.73 µg/mL. IC50 value indicated that 2',4-dihydroxy-3-methoxychalcone and 2',4',4-trihydroxy-3-methoxychalcone potential as inhibitors in Hela, WiDr and T47D cell lines.

Sontochin as a Guide to the Development of Drugs against Chloroquine-Resistant Malaria

PubMed Central

Pou, Sovitj; Winter, Rolf W.; Nilsen, Aaron; Kelly, Jane Xu; Li, Yuexin; Doggett, J. Stone; Riscoe, Erin W.; Wegmann, Keith W.; Hinrichs, David J.

2012-01-01

Sontochin was the original chloroquine replacement drug, arising from research by Hans Andersag 2 years after chloroquine (known as “resochin” at the time) had been shelved due to the mistaken perception that it was too toxic for human use. We were surprised to find that sontochin, i.e., 3-methyl-chloroquine, retains significant activity against chloroquine-resistant strains of Plasmodium falciparum in vitro. We prepared derivatives of sontochin, “pharmachins,” with alkyl or aryl substituents at the 3 position and with alterations to the 4-position side chain to enhance activity against drug-resistant strains. Modified with an aryl substituent in the 3 position of the 7-chloro-quinoline ring, Pharmachin 203 (PH-203) exhibits low-nanomolar 50% inhibitory concentrations (IC50s) against drug-sensitive and multidrug-resistant strains and in vivo efficacy against patent infections of Plasmodium yoelii in mice that is superior to chloroquine. Our findings suggest that novel 3-position aryl pharmachin derivatives have the potential for use in treating drug resistant malaria. PMID:22508305

Pharmacophore-based design and discovery of (-)-meptazinol carbamates as dual modulators of cholinesterase and amyloidogenesis.

PubMed

Xie, Qiong; Zheng, Zhaoxi; Shao, Biyun; Fu, Wei; Xia, Zheng; Li, Wei; Sun, Jian; Zheng, Wei; Zhang, Weiwei; Sheng, Wei; Zhang, Qihong; Chen, Hongzhuan; Wang, Hao; Qiu, Zhuibai

2017-12-01

Multifunctional carbamate-type acetylcholinesterase (AChE) inhibitors with anti-amyloidogenic properties like phenserine are potential therapeutic agents for Alzheimer's disease (AD). We reported here the design of new carbamates using pharmacophore model strategy to modulate both cholinesterase and amyloidogenesis. A five-feature pharmacophore model was generated based on 25 carbamate-type training set compounds. (-)-Meptazinol carbamates that superimposed well upon the model were designed and synthesized, which exhibited nanomolar AChE inhibitory potency and good anti-amyloidogenic properties in in vitro test. The phenylcarbamate 43 was highly potent (IC 50 31.6 nM) and slightly selective for AChE, and showed low acute toxicity. In enzyme kinetics assay, 43 exhibited uncompetitive inhibition and reacted by pseudo-irreversible mechanism. 43 also showed amyloid-β (Aβ) lowering effects (51.9% decrease of Aβ 42 ) superior to phenserine (31% decrease of total Aβ) in SH-SY5Y-APP 695 cells at 50 µM. The dual actions of 43 on cholinergic and amyloidogenic pathways indicated potential uses as symptomatic and disease-modifying agents.

EI-2128-1, a novel interleukin-1beta converting enzyme inhibitor produced by Penicillium sp. E-2128.

PubMed

Koizumi, Fumito; Agatsuma, Tsutomu; Ando, Katsuhiko; Kondo, Hidemasa; Saitoh, Yutaka; Matsuda, Yuzuru; Nakanishi, Satoshi

2003-11-01

EI-2128-1, a novel interleukin-1beta converting enzyme (ICE) inhibitor, was isolated from the culture broths of Penicillium sp. E-2128. EI-2128-1 selectively inhibited human recombinant ICE activity with IC50 value of 0.59 microM, without inhibiting elastase and cathepsin B. EI-2128-1 also inhibited mature interleukin-1beta secretion from THP-1 cells induced by LPS with IC50 value of 0.28 microM.

MMB-4 Inhibition of Aceylcholinesterase Is Similar across Species

DTIC Science & Technology

2014-11-01

version 5.4). An IC50 value was determined for AChE from each animal species by fitting the percent of AChE activity with respect to MMB 4 concentration...in GraphPad Prism (version 5) using a nonlinear regression dose response model for inhibition (normalized response with variable slope). Assessing the...Therefore, AChE activity and inhibition studies were carried out at 435 nm to reduce interference from MMB 4. Comparison of IC50 Values for MMB 4 with AChE

Capsofulvesins A-C, cholinesterase inhibitors from Capsosiphon fulvescens.

PubMed

Fang, Zhe; Yang Jeong, Su; Ah Jung, Hyun; Sue Choi, Jae; Sun Min, Byung; Hee Woo, Mi

2012-01-01

Activity-directed isolation of the n-hexane and dichloromethane fractions of Capsosiphon fulvescens resulted in the identification of four new glycolipids (1-3): (2S)-1-O-(6Z,9Z,12Z,15Z-octadecatetraenoyl)-2-O-(4Z,7Z,10Z,13Z-hexadecatetraenoyl)-3-O-β-D-galactopyranosyl glycerol (1, capsofulvesin A), (2S)-l-O-(9Z,12Z,15Z-octadecatrienoyl)-2-O-(10Z,13Z-hexadecadienoyl)-3-O-β-D-galactopyranosyl glycerol (2, capsofulvesin B), (2S)-1-O-(6Z,9Z,12Z,15Z-octadecatetraenoyl)-3-O-β-D-galacatopyranosyl glycerol (3, capsofulvesin C). Compounds 1-6 exhibited acetylcholinesterase (AChE) inhibitory activities with IC(50) values ranging from 50.90 to 82.83 µM, whereas 2-6 showed butyrylcholinesterase (BChE) inhibitory activities with IC(50) values of 114.75-185.55 µM. Although most of the compounds isolated lacked scavenging activity for 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and peroxynitrite (ONOO(-)), compound 8 showed ONOO(-) scavenging activity with an IC(50) value of 26.23 µg/mL.

Inhibitory effects of psychotropic drugs on the acetylcholine receptor-operated potassium current (IK.ACh) in guinea-pig atrial myocytes.

PubMed

Okada, Muneyoshi; Watanabe, Shinya; Matada, Takashi; Asao, Yoko; Hamatani, Ramu; Yamawaki, Hideyuki; Hara, Yukio

2013-01-01

Influences of psychotropic drugs, six antipsychotics and three antidepressants, on acetylcholine receptor-operated potassium current (IK.ACh) were examined by a whole-cell patch clamp method in freshly isolated guinea-pig atrial myocyte. IK.ACh was induced by a superfusion of carbachol (CCh) or by an intracellular application of guanosine 5'-[thio] triphosphate (GTPγS). To elucidate mechanism for anticholinergic action, IC50 ratio, the ratio of IC50 for GTPγS-activated IK.ACh to CCh-induced IK.ACh, was calculated. Antipsychotics and antidepressants inhibited CCh-induced IK.ACh in a concentration-dependent manner. The IC50 values were as follows; chlorpromazine 0.53 μM, clozapine 0.06 μM, fluphenazine 2.69 μM, haloperidol 2.66 μM, sulpiride 42.3 μM, thioridazine 0.07 μM, amitriptyline 0.03 μM, imipramine 0.22 μM and maprotiline 1.81 μM. The drugs, except for sulpiride, inhibited GTPγS-activated IK.ACh with following IC50 values; chlorpromazine 1.71 μM, clozapine 14.9 μM, fluphenazine 3.55 μM, haloperidol 2.73 μM, thioridazine 1.90 μM, amitriptyline 7.55 μM, imipramine 7.09 μM and maprotiline 5.93 μM. The IC50 ratio for fluphenazine and haloperidol was close to unity. The IC50 ratio for chlorpromazine, clozapine, thioridazine, amitriptyline, imipramine and maprotiline was much higher than unity. The present findings suggest that the psychotropics studied suppress IK.ACh. Chlorpromazine, clozapine, thioridazine, amitriptyline, imipramine, maprotiline and sulpiride are preferentially acting on muscarinic receptor. Fluphenazine and haloperidol may act on G protein and/or potassium channel.

Inhibition of Procarcinogen Activating Enzyme CYP1A2 Activity and Free Radical Formation by Caffeic Acid and its Amide Analogues.

PubMed

Narongchai, Paitoon; Niwatananun, Kanokporn; Narongchai, Siripun; Kusirisin, Winthana; Jaikang, Churdsak

2016-01-01

Caffeic acid (CAF) and its amide analogues, ethyl 1-(3',4'-dihydroxyphenyl) propen amide (EDPA), phenethyl 1-(3',4'-dihydroxyphenyl) propen amide (PEDPA), phenmethyl 1- (3',4'-dihydroxyphenyl) propen amide (PMDPA) and octyl 1-(3',4'-dihydroxyphenyl) propen amide (ODPA) were investigated for the inhibition of procarcinogen activating enzyme. CYP1A2 and scavenging activity on formation of nitric oxide, superoxide anion, DPPH radical and hydroxyl radical. It was found that they inhibited CYP1A2 enzyme by uncompetitive inhibition. Apparent Ki values of CAF, EDPA, PEDPA, PMDPA and ODPA were 0.59, 0.39, 0.45, 0.75 and 0.80 µM, respectively suggesting potent inhibitors of CYP1A2. Moreover, they potentially scavenged nitric oxide radical with IC 50 values of 0.12, 0.22, 0.28, 0.22 and 0.51 mM, respectively. The IC50 values of superoxide anion scavenging were 0.20, 0.22, 0.44, 2.18 and 2.50 mM, respectively. 1, 1- diphenyl-2- picrylhydrazyl (DPPH) radical-scavenging ability, shown as IC50 values, were 0.41, 0.29, 0.30, 0.89 and 0.84 mM, respectively. Moreover, the hydroxyl radical scavenging in vitro model was shown as IC50 values of 23.22, 21.06, 17.10, 17.21 and 15.81 µM, respectively. From our results, caffeic acid and its amide analogues are in vitro inhibitors of human CYP1A2 catalytic activity and free radical formation. They may be useful to be developed as potential chemopreventive agents that block CYP1A2-mediated chemical carcinogenesis.

Synthesis of 4-thiazolidinone analogs as potent in vitro anti-urease agents.

PubMed

Rahim, Fazal; Zaman, Khalid; Ullah, Hayat; Taha, Muhammad; Wadood, Abdul; Javed, Muhammad Tariq; Rehman, Wajid; Ashraf, Muhammad; Uddin, Reaz; Uddin, Imad; Asghar, Humna; Khan, Aftab Ahmad; Khan, Khalid M

2015-12-01

4-Thiazolidinone analogs 1-20 were synthesized, characterized by (1)H NMR and EI-MS and investigated for urease inhibitory activity. All twenty (20) analogs exhibited varied degree of urease inhibitory potential with IC50 values 1.73-69.65μM, if compared with standard thiourea having IC50 value of 21.25±0.15μM. Among the series, eight derivatives 3, 6, 8, 10, 15, 17, 19, and 20 showed outstanding urease inhibitory potential with IC50 values of 9.34±0.02, 14.62±0.03, 8.43±0.01, 7.3±0.04, 2.31±0.002, 5.75±0.003, 8.81±0.005, and 1.73±0.001μM, respectively, which is better than the standard thiourea. The remaining analogs showed good to excellent urease inhibition. The binding interactions of these compounds were confirmed through molecular docking studies. Copyright © 2015 Elsevier Inc. All rights reserved.

Bioactive compounds from Stuhlmannia moavi from the Madagascar dry forest.

PubMed

Liu, Yixi; Harinantenaina, Liva; Brodie, Peggy J; Bowman, Jessica D; Cassera, Maria B; Slebodnick, Carla; Callmander, Martin W; Randrianaivo, Richard; Rakotobe, Etienne; Rasamison, Vincent E; Applequist, Wendy; Birkinshaw, Chris; Lewis, Gwilym P; Kingston, David G I

2013-12-15

Bioassay-directed fractionation of the leaf and root extracts of the antiproliferative Madagascar plant Stuhlmannia moavi afforded 6-acetyl-5,8-dihydroxy-2-methoxy-7-methyl-1,4-naphthoquinone (stuhlmoavin, 1) as the most active compound, with an IC50 value of 8.1 μM against the A2780 human ovarian cancer cell line, as well as the known homoisoflavonoid bonducellin (2) and the stilbenoids 3,4,5'-trihydroxy-3'-methoxy-trans-stilbene (3), piceatannol (4), resveratrol (5), rhapontigenin (6), and isorhapontigenin (7). The structure elucidation of all compounds was based on NMR and mass spectroscopic data, and the structure of 1 was confirmed by a single crystal X-ray analysis. Compounds 2-5 showed weak A2780 activities, with IC50 values of 10.6, 54.0, 41.0, and 74.0 μM, respectively. Compounds 1-3 also showed weak antimalarial activity against Plasmodium falciparum with IC50 values of 23, 26, and 27 μM, respectively. Copyright © 2013 Elsevier Ltd. All rights reserved.

Novel Marine Phenazines as Potential Cancer Chemopreventive and Anti-Inflammatory Agents

PubMed Central

Kondratyuk, Tamara P.; Park, Eun-Jung; Yu, Rui; van Breemen, Richard B.; Asolkar, Ratnakar N.; Murphy, Brian T.; Fenical, William; Pezzuto, John M.

2012-01-01

Two new (1 and 2) and one known phenazine derivative (lavanducyanin, 3) were isolated and identified from the fermentation broth of a marine-derived Streptomyces sp. (strain CNS284). In mammalian cell culture studies, compounds 1, 2 and 3 inhibited TNF-α-induced NFκB activity (IC50 values of 4.1, 24.2, and 16.3 μM, respectively) and LPS-induced nitric oxide production (IC50 values of >48.6, 15.1, and 8.0 μM, respectively). PGE2 production was blocked with greater efficacy (IC50 values of 7.5, 0.89, and 0.63 μM, respectively), possibly due to inhibition of cyclooxygenases in addition to the expression of COX-2. Treatment of cultured HL-60 cells led to dose-dependent accumulation in the subG1 compartment of the cell cycle, as a result of apoptosis. These data provide greater insight on the biological potential of phenazine derivatives, and some guidance on how various substituents may alter potential anti-inflammatory and anti-cancer effects. PMID:22412812

Protective effect of unsymmetrical dichalcogenide, a novel antioxidant agent, in vitro and an in vivo model of brain oxidative damage.

PubMed

Prigol, Marina; Wilhelm, Ethel A; Schneider, Caroline C; Nogueira, Cristina W

2008-11-25

Unsymmetrical dichalcogenides, a class of organoselenium compounds, were screened for antioxidant activity in rat brain homogenates in vitro. Unsymmetrical dichalcogenides (1-3) were tested against lipid peroxidation induced by sodium nitroprusside (SNP) or malonate, and reactive species (RS) production induced by sodium azide in rat brain homogenates. Compounds 1 (without a substituent at the phenyl group), 2 (chloro substituent at the phenyl group bounded to the sulfur atom) and 3 (chloro substituent at the phenyl group bounded to the selenium atom) protected against lipid peroxidation induced by SNP. The IC50 values followed the order 3<2<1. Lipid peroxidation induced by malonate was also reduced by dichalcogenides 1, 2 and 3. The IC50 values were 3

Reversal of in vitro cellular MRP1 and MRP2 mediated vincristine resistance by the flavonoid myricetin.

PubMed

van Zanden, Jelmer J; de Mul, Anika; Wortelboer, Heleen M; Usta, Mustafa; van Bladeren, Peter J; Rietjens, Ivonne M C M; Cnubben, Nicole H P

2005-06-01

In the present study, the effects of myricetin on either MRP1 or MRP2 mediated vincristine resistance in transfected MDCKII cells were examined. The results obtained show that myricetin can inhibit both MRP1 and MRP2 mediated vincristine efflux in a concentration dependent manner. The IC50 values for cellular vincristine transport inhibition by myricetin were 30.5+/-1.7 microM for MRP1 and 24.6+/-1.3 microM for MRP2 containing MDCKII cells. Cell proliferation analysis showed that the MDCKII control cells are very sensitive towards vincristine toxicity with an IC50 value of 1.1+/-0.1 microM. The MDCKII MRP1 and MRP2 cells are less sensitive towards vincristine toxicity with IC50 values of 33.1+/-1.9 and 22.2+/-1.4 microM, respectively. In both the MRP1 and MRP2 cells, exposure to 25 microM myricetin enhances the sensitivity of the cells towards vincristine toxicity to IC50 values of 7.6+/-0.5 and 5.8+/-0.5 microM, respectively. The increase of sensitivity represents a reversal of the resistance towards vincristine as a result of MRP1 and MRP2 inhibition. Thus, the present study demonstrates the ability of the flavonoid myricetin to modulate MRP1 and MRP2 mediated resistance to the anticancer drug vincristine in transfected cells, indicating that flavonoids might be a valuable adjunct to chemotherapy to block MRP mediated resistance.

Compounds from Sedum caeruleum with antioxidant, anticholinesterase, and antibacterial activities.

PubMed

Bensouici, Chawki; Kabouche, Ahmed; Karioti, Anastasia; Öztürk, Mehmet; Duru, Mehmet Emin; Bilia, Anna Rita; Kabouche, Zahia

2016-01-01

This is the first study on the phytochemistry, antioxidant, anticholinesterase, and antibacterial activities of Sedum caeruleum L. (Crassulaceae). The objective of this study is to isolate the secondary metabolites and determine the antioxidant, anticholinesterase, and antibacterial activities of S. caeruleum. Six compounds (1-6) were isolated from the extracts of S. caeruleum and elucidated using UV, 1D-, 2D-NMR, and MS techniques. Antioxidant activity was investigated using DPPH(•), CUPRAC, and ferrous-ions chelating assays. Anticholinesterase activity was determined against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes using the Ellman method. Antibacterial activity was performed according to disc diffusion and minimum inhibitory concentration (MIC) methods. Isolated compounds were elucidated as ursolic acid (1), daucosterol (2), β-sitosterol-3-O-β-D-galactopyranoside (3), apigenin (4), apigetrin (5), and apiin (6). The butanol extract exhibited highest antioxidant activity in all tests (IC50 value: 28.35 ± 1.22 µg/mL in DPPH assay, IC50 value: 40.83 ± 2.24 µg/L in metal chelating activity, and IC50 value: 23.52 ± 0.44 µg/L in CUPRAC), and the highest BChE inhibitory activity (IC50 value: 36.89 ± 0.15 µg/L). Moreover, the chloroform extract mildly inhibited (MIC value: 80 µg/mL) the growth of all the tested bacterial strains. Ursolic acid (1), daucosterol (2), β-sitosterol-3-O-β-D-galactopyranoside (3), apigenin (4), apigetrin (5), and apiin (6) were isolated from Sedum caeruleum for the first time. In addition, a correlation was observed between antioxidant and anticholinesterase activities of bioactive ingredients of this plant.

Identification of a novel multiple kinase inhibitor with potent antiviral activity against influenza virus by reducing viral polymerase activity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sasaki, Yutaka; Kakisaka, Michinori; Chutiwitoonchai, Nopporn

Highlights: • Screening of 50,000 compounds and subsequent lead optimization identified WV970. • WV970 has antiviral effects against influenza A, B and highly pathogenic viral strains. • WV970 inhibits viral genome replication and transcription. • A target database search suggests that WV970 may bind to a number of kinases. • KINOMEscan screening revealed that WV970 has inhibitory effects on 15 kinases. - Abstract: Neuraminidase inhibitors are the only currently available influenza treatment, although resistant viruses to these drugs have already been reported. Thus, new antiviral drugs with novel mechanisms of action are urgently required. In this study, we identified amore » novel antiviral compound, WV970, through cell-based screening of a 50,000 compound library and subsequent lead optimization. This compound exhibited potent antiviral activity with nanomolar IC{sub 50} values against both influenza A and B viruses but not non-influenza RNA viruses. Time-of-addition and indirect immunofluorescence assays indicated that WV970 acted at an early stage of the influenza life cycle, but likely after nuclear entry of viral ribonucleoprotein (vRNP). Further analyses of viral RNA expression and viral polymerase activity indicated that WV970 inhibited vRNP-mediated viral genome replication and transcription. Finally, structure-based virtual screening and comprehensive human kinome screening were used to demonstrate that WV970 acts as a multiple kinase inhibitor, many of which are associated with influenza virus replication. Collectively, these results strongly suggest that WV970 is a promising anti-influenza drug candidate and that several kinases associated with viral replication are promising drug targets.« less

Toxicity evaluation and prediction of toxic chemicals on activated sludge system.

PubMed

Cai, Bijing; Xie, Li; Yang, Dianhai; Arcangeli, Jean-Pierre

2010-05-15

The gaps of data for evaluating toxicity of new or overloaded organic chemicals on activated sludge system resulted in the requirements for methodology of toxicity estimation. In this study, 24 aromatic chemicals typically existed in the industrial wastewater were selected and classified into three groups of benzenes, phenols and anilines. Their toxicity on activated sludge was then investigated. Two indexes of IC(50-M) and IC(50-S) were determined respectively from the respiration rates of activated sludge with different toxicant concentration at mid-term (24h) and short-term (30min) time intervals. Experimental results showed that the group of benzenes was the most toxic, followed by the groups of phenols and anilines. The values of IC(50-M) of the tested chemicals were higher than those of IC(50-S). In addition, quantitative structure-activity relationships (QSARs) models developed from IC(50-M) were more stable and accurate than those of IC(50-S). The multiple linear models based on molecular descriptors and K(ow) presented better reliability than single linear models based on K(ow). Among these molecular descriptors, E(lumo) was the most important impact factor for evaluation of mid-term toxicity. Copyright (c) 2009 Elsevier B.V. All rights reserved.

Synthesis and biological evaluation of novel thiadiazole amides as potent Cdc25B and PTP1B inhibitors.

PubMed

Li, Yingjun; Yu, Yang; Jin, Kun; Gao, Lixin; Luo, Tongchuan; Sheng, Li; Shao, Xin; Li, Jia

2014-09-01

A series of novel thiadiazole amide derivatives have been synthesized and evaluated for inhibitory activities against Cdc25B and PTP1B. Most of them showed inhibitory activities against Cdc25B (IC50=1.18-8.01 μg/mL) and PTP1B (IC50=0.85-8.75 μg/mL), respectively. Moreover, compounds 5b and 4l were most potent with IC50 values of 1.18 and 0.85 μg/mL for Cdc25B and PTP1B, respectively, compared with reference drugs Na3VO4 (IC50=0.93 μg/mL) and oleanolic acid (IC50=0.85 μg/mL). The results of selectivity experiments showed that the target compounds were selective inhibitors against PTP1B and Cdc25B. Enzyme kinetic experiments demonstrated that compound 5k was a specific inhibitor with the typical characteristics of a mixed inhibitor. Copyright © 2014 Elsevier Ltd. All rights reserved.

Validation and Clinical Utility of the hERG IC50:Cmax Ratio to Determine the Risk of Drug-Induced Torsades de Pointes: A Meta-Analysis.

PubMed

Lehmann, David F; Eggleston, William D; Wang, Dongliang

2018-03-01

Use of the QT interval corrected for heart rate (QTc) on the electrocardiogram (ECG) to predict torsades de pointes (TdP) risk from culprit drugs is neither sensitive nor specific. The ratio of the half-maximum inhibitory concentration of the hERG channel (hERG IC50) to the peak serum concentration of unbound drug (C max ) is used during drug development to screen out chemical entities likely to cause TdP. To validate the use of the hERG IC50:C max ratio to predict TdP risk from a culprit drug by its correlation with TdP incidence. Medline (between 1966 and March 2017) was accessed for hERG IC50 and C max values from the antihistamine, fluoroquinolone, and antipsychotic classes to identify cases of drug-induced TdP. Exposure to a culprit drug was estimated from annual revenues reported by the manufacturer. Inclusion criteria for TdP cases were provision of an ECG tracing that demonstrated QTc prolongation with TdP and normal serum values of potassium, calcium, and magnesium. Cases reported in patients with a prior rhythm disturbance and those involving a drug interaction were excluded. The Meta-Analysis of Observational Studies in Epidemiology checklist was used for epidemiological data extraction by two authors. Negligible risk drugs were defined by an hERG IC50:C max ratio that correlated with less than a 5% chance of one TdP event for every 100 million exposures (relative risk [RR] 1.0). The hERG IC50:C max ratio correlated with TdP risk (0.312; 95% confidence interval 0.205-0.476, p<0.0001), a ratio of 80 (RR 1.0). The RR from olanzapine is on par with loratadine; ziprasidone is comparable with ciprofloxacin. Drugs with an RR greater than 50 include astemizole, risperidone, haloperidol, and thioridazine. The hERG IC50:C max ratio was correlated with TdP incidence for culprit drugs. This validation provides support for the potential use of the hERG IC50:C max ratio for clinical decision making in instances of drug selection where TdP risk is a concern. © 2018 Pharmacotherapy Publications, Inc.

Phytochemical profile and biological activities of Deverra tortuosa (Desf.)DC.: a desert aromatic shrub widespread in Northern Region of Saudi Arabia.

PubMed

Guetat, Arbi; Boulila, Abdennacer; Boussaid, Mohamed

2018-04-16

The present study describes the chemical composition of the essential oil of different plant parts of Devrra tortuosa; in vivo and in vitro biological activities of plant extract and essential oils. Apiol was found to be the major component of the oil (between 65.73% and 74.41%). The best antioxidant activities were observed for the oil of flowers (IC50 = 175 μg/ml). The samples of stems and roots exhibit lower antioxidant activity (IC50 = 201 μg/ml and 182 μg/ml, respectively). The values of IC50 showed that the extracts of methanol exhibit the highest antioxidants activities (IC50 = 64.8 102 μg/ml). EOs showed excellent antifungal activity against yeasts with low azole susceptibilities (i.e. Malassezia spp. and Candida krusei). The MIC values of oils varied between 2.85 mg/mL and 27 mg/mL. The obtained results also showed that the plant extracts inhibited the germination and the shoot and root growth of Triticum æstivum seedlings.

Chemical and biological analyses of the essential oils and main constituents of Piper species.

PubMed

Moura do Carmo, Dominique F; Amaral, Ana Cláudia Fernandes; Machado, Gérzia M C; Leon, Leonor Laura; Silva, Jefferson Rocha de Andrade

2012-02-13

The essential oils obtained from leaves of Piper duckei and Piper demeraranum by hydrodistillation were analyzed by gas chromatography-mass spectrometry. The main constituents found in P. demeraranum oil were limonene (19.3%) and β-elemene (33.1%) and in P. duckei oil the major components found were germacrene D (14.7%) and trans-caryophyllene (27.1%). P. demeraranum and P. duckei oils exhibited biological activity, with IC(50) values between 15 to 76 μg mL(-1) against two Leishmania species, P. duckei oil being the most active. The cytotoxicity of the essential oils on mice peritoneal macrophage cells was insignificant, compared with the toxicity of pentamidine. The main mono- and sesquiterpene, limonene (IC(50) = 278 μM) and caryophyllene (IC(50) = 96 μM), were tested against the strains of Leishmania amazonensis, and the IC(50) values of these compounds were lower than those found for the essential oils of the Piper species. The HET-CAM test was used to evaluate the irritation potential of these oils as topical products, showing that these oils can be used as auxiliary medication in cases of cutaneous leishmaniasis, with less side effects and lower costs.

Synthesis and in vitro acetylcholinesterase and butyrylcholinesterase inhibitory potential of hydrazide based Schiff bases.

PubMed

Rahim, Fazal; Ullah, Hayat; Taha, Muhammad; Wadood, Abdul; Javed, Muhammad Tariq; Rehman, Wajid; Nawaz, Mohsan; Ashraf, Muhammad; Ali, Muhammad; Sajid, Muhammad; Ali, Farman; Khan, Muhammad Naseem; Khan, Khalid Mohammed

2016-10-01

To discover multifunctional agents for the treatment of Alzheimer's disease, a series of hydrazide based Schiff bases were designed and synthesized based on multitarget-directed strategy. We have synthesized twenty-eight analogs of hydrazide based Schiff bases, characterized by various spectroscopic techniques and evaluated in vitro for acetylcholinesterase and butyrylcholinesterase inhibition. All compounds showed varied degree of acetylcholinesterase and butyrylcholinesterase inhibition when compared with standard Eserine. Among the series, compounds 10, 3 and 24 having IC50 values 4.12±0.01, 8.12±0.01 and 8.41±0.06μM respectively showed potent acetylcholinesterase inhibition when compared with Eserine (IC50=0.85±0.0001μM). Three compounds 13, 24 and 3 having IC50 values 6.51±0.01, 9.22±0.07 and 37.82±0.14μM respectively showed potent butyrylcholinesterase inhibition by comparing with eserine (IC50=0.04±0.0001μM). The remaining compounds also exhibited moderate to weak inhibitory potential. Structure activity relationship has been established. Through molecular docking studies the binding interaction was confirmed. Copyright © 2016 Elsevier Inc. All rights reserved.

3-Coumaranone derivatives as inhibitors of monoamine oxidase.

PubMed

Van Dyk, Adriaan S; Petzer, Jacobus P; Petzer, Anél; Legoabe, Lesetja J

2015-01-01

The present study examines the monoamine oxidase (MAO) inhibitory properties of a series of 20 3-coumaranone [benzofuran-3(2H)-one] derivatives. The 3-coumaranone derivatives are structurally related to series of α-tetralone and 1-indanone derivatives, which have recently been shown to potently inhibit MAO, with selectivity for MAO-B (in preference to the MAO-A isoform). 3-Coumaranones are similarly found to selectively inhibit human MAO-B with half-maximal inhibitory concentration (IC50) values of 0.004-1.05 µM. Nine compounds exhibited IC50<0.05 µM for the inhibition of MAO-B. For the inhibition of human MAO-A, IC50 values ranged from 0.586 to >100 µM, with only one compound possessing an IC50<1 µM. For selected 3-coumaranone derivatives, it is established that MAO-A and MAO-B inhibition are reversible since dialysis of enzyme-inhibitor mixtures almost completely restores enzyme activity. On the basis of the selectivity profiles and potent action, it may be concluded that the 3-coumaranone derivatives are suitable leads for the development of selective MAO-B inhibitors as potential treatment for disorders such as Parkinson's disease and Alzheimer's disease.

3-Coumaranone derivatives as inhibitors of monoamine oxidase

PubMed Central

Van Dyk, Adriaan S; Petzer, Jacobus P; Petzer, Anél; Legoabe, Lesetja J

2015-01-01

The present study examines the monoamine oxidase (MAO) inhibitory properties of a series of 20 3-coumaranone [benzofuran-3(2H)-one] derivatives. The 3-coumaranone derivatives are structurally related to series of α-tetralone and 1-indanone derivatives, which have recently been shown to potently inhibit MAO, with selectivity for MAO-B (in preference to the MAO-A isoform). 3-Coumaranones are similarly found to selectively inhibit human MAO-B with half-maximal inhibitory concentration (IC50) values of 0.004–1.05 µM. Nine compounds exhibited IC50<0.05 µM for the inhibition of MAO-B. For the inhibition of human MAO-A, IC50 values ranged from 0.586 to >100 µM, with only one compound possessing an IC50<1 µM. For selected 3-coumaranone derivatives, it is established that MAO-A and MAO-B inhibition are reversible since dialysis of enzyme–inhibitor mixtures almost completely restores enzyme activity. On the basis of the selectivity profiles and potent action, it may be concluded that the 3-coumaranone derivatives are suitable leads for the development of selective MAO-B inhibitors as potential treatment for disorders such as Parkinson’s disease and Alzheimer’s disease. PMID:26491258

In vitro synergism of trifluorothymidine and ganciclovir against HSV-1.

PubMed

Hobden, Jeffery A; Kumar, Manish; Kaufman, Herbert E; Clement, Christian; Varnell, Emily D; Bhattacharjee, Partha S; Hill, James M

2011-02-01

To determine whether trifluorothymidine (TFT) and ganciclovir (GCV) are synergistic against herpes simplex virus type 1 (HSV-1). TFT and GCV activity against 12 strains of HSV-1 (including an acyclovir-resistant strain) was measured by plaque-forming unit (PFU) inhibition. Cellular toxicity was assessed with an MTT dye reduction assay. Synergism was determined by calculating fractional inhibitory concentration (FIC indices) based on PFU reduction. Concentrations of TFT resulting in 50% inhibition of PFUs (IC(50)) of acyclovir-susceptible HSV-1 strains ranged from 3.07 ± 0.36 to 12.52 ± 0.61 μM. GCV IC(50) values ranged from 0.40 ± 0.02 to 1.59 ± 0.14 μM. IC(50) values of TFT and GCV against the acyclovir-resistant strain were 15.40 ± 3.17 and 93.00 ± 9.64 μM, respectively. Concentrations of TFT or GCV resulting in 50% cell cytotoxicity (CC(50)) were 0.99 ± 0.01 and 92.91 ± 8.92 μM, respectively. TFT and GCV combined (10:1) were 10 times more potent against all acyclovir-susceptible HSV-1 strains. For 8 of 12 HSV-1 strains, the IC(50) of TFT and GCV combined was lower than the CC(50) of either drug. For acyclovir-susceptible HSV-1 strains, TFT and GCV combined generated a FIC index of <0.5, suggesting strong synergism between the two drugs. The FIC value for TFT and GCV combined against the acyclovir-resistant HSV-1 strain was 0.84, indicating nonantagonism. TFT and GCV are synergistic against acyclovir-susceptible HSV-1 at concentrations significantly less toxic than if each antiviral were used as a sole agent.

In Vitro Synergism of Trifluorothymidine and Ganciclovir against HSV-1

PubMed Central

Hobden, Jeffery A.; Kumar, Manish; Kaufman, Herbert E.; Clement, Christian; Varnell, Emily D.; Bhattacharjee, Partha S.

2011-01-01

Purpose. To determine whether trifluorothymidine (TFT) and ganciclovir (GCV) are synergistic against herpes simplex virus type 1 (HSV-1). Methods. TFT and GCV activity against 12 strains of HSV-1 (including an acyclovir-resistant strain) was measured by plaque-forming unit (PFU) inhibition. Cellular toxicity was assessed with an MTT dye reduction assay. Synergism was determined by calculating fractional inhibitory concentration (FIC indices) based on PFU reduction. Results. Concentrations of TFT resulting in 50% inhibition of PFUs (IC50) of acyclovir-susceptible HSV-1 strains ranged from 3.07 ± 0.36 to 12.52 ± 0.61 μM. GCV IC50 values ranged from 0.40 ± 0.02 to 1.59 ± 0.14 μM. IC50 values of TFT and GCV against the acyclovir-resistant strain were 15.40 ± 3.17 and 93.00 ± 9.64 μM, respectively. Concentrations of TFT or GCV resulting in 50% cell cytotoxicity (CC50) were 0.99 ± 0.01 and 92.91 ± 8.92 μM, respectively. TFT and GCV combined (10:1) were 10 times more potent against all acyclovir-susceptible HSV-1 strains. For 8 of 12 HSV-1 strains, the IC50 of TFT and GCV combined was lower than the CC50 of either drug. For acyclovir-susceptible HSV-1 strains, TFT and GCV combined generated a FIC index of <0.5, suggesting strong synergism between the two drugs. The FIC value for TFT and GCV combined against the acyclovir-resistant HSV-1 strain was 0.84, indicating nonantagonism. Conclusions. TFT and GCV are synergistic against acyclovir-susceptible HSV-1 at concentrations significantly less toxic than if each antiviral were used as a sole agent. PMID:20861476

Antileishmanial and antitrypanosomal activities of the 8-aminoquinoline tafenoquine.

PubMed

Yardley, Vanessa; Gamarro, Francisco; Croft, Simon L

2010-12-01

The 8-aminoquinoline tafenoquine showed significant in vitro activity against Leishmania species, including L. donovani amastigotes in macrophages, with 50% inhibitory concentrations (IC(50)s) between 0.1 and 4.0 μM for both pentavalent antimony (SbV)-sensitive and SbV-resistant strains and by oral administration in BALB/c mice, with 50% effective dose (ED(50)) values of 1.2 to 3.5 mg/kg for 5 days. Tafenoquine was less active against intracellular Trypanosoma cruzi amastigotes, with an IC(50) of 21.9 μM.

Antileishmanial and Antitrypanosomal Activities of the 8-Aminoquinoline Tafenoquine ▿

PubMed Central

Yardley, Vanessa; Gamarro, Francisco; Croft, Simon L.

2010-01-01

The 8-aminoquinoline tafenoquine showed significant in vitro activity against Leishmania species, including L. donovani amastigotes in macrophages, with 50% inhibitory concentrations (IC50s) between 0.1 and 4.0 μM for both pentavalent antimony (SbV)-sensitive and SbV-resistant strains and by oral administration in BALB/c mice, with 50% effective dose (ED50) values of 1.2 to 3.5 mg/kg for 5 days. Tafenoquine was less active against intracellular Trypanosoma cruzi amastigotes, with an IC50 of 21.9 μM. PMID:20837750

Identification of New Human Malaria Parasite Plasmodium Falciparum Dihydroorotate Dehydrogenase Inhibitors by Pharmacophore and Structure-Based Virtual Screening

PubMed Central

Pavadai, Elumalai; El Mazouni, Farah; Wittlin, Sergio; de Kock, Carmen; Phillips, Margaret A.; Chibale, Kelly

2016-01-01

Plasmodium falciparum dihydroorotate dehydrogenase (PfDHODH), a key enzyme in the de novo pyrimidine biosynthesis pathway, which the Plasmodium falciparum relies on exclusively for survival, has emerged as a promising target for antimalarial drugs. In an effort to discover new and potent PfDHODH inhibitors, 3D-QSAR pharmacophore models were developed based on the structures of known PfDHODH inhibitors and the validated Hypo1 model was used as a 3D search query for virtual screening of the National Cancer Institute database. The virtual hit compounds were further filtered based on molecular docking and Molecular Mechanics/Generalized Born Surface Area binding energy calculations. The combination of the pharmacophore and structure-based virtual screening resulted in the identification of nine new compounds that showed >25% inhibition of PfDHODH at a concentration of 10 μM, three of which exhibited IC50 values in the range of 0.38–20 μM. The most active compound, NSC336047, displayed species-selectivity for PfDHODH over human DHODH and inhibited parasite growth with an IC50 of 26 μM. In addition to this, thirteen compounds inhibited parasite growth with IC50 values of ≤ 50 μM, four of which showed IC50 values in the range of 5–12 μM. These compounds could be further explored in the identification and development of more potent PfDHODH and parasite growth inhibitors. PMID:26915022

Biological activities of aqueous extract from Cinnamomum porrectum

NASA Astrophysics Data System (ADS)

Farah, H. Siti; Nazlina, I.; Yaacob, W. A.

2013-11-01

A study was carried out to evaluate biological activities of an extract obtained from Cinnamomum porrectum under reflux using water. Aqueous extract of Cinnamomum porrectum was tested for antibacterial activity against six Gram-positive and eight Gram-negative bacteria as well as MRSA. The results confirmed that the aqueous extract of Cinnamomum porrectum was bactericidal. Cytotoxic tests on Vero cell culture revealed that Cinnamomum porrectum was non-toxic which IC50 value higher than 0.02 mg/mL. Antiviral activity was tested based on the above IC50 values together with the measured EC50 values to obtain Therapeutic Index. The result showed that Cinnamomum porrectum has the ability to inhibit viral replication of HSV-1 in Vero cells.

Chemical Constituents of Muehlenbeckia tamnifolia (Kunth) Meisn (Polygonaceae) and Its In Vitro α-Amilase and α-Glucosidase Inhibitory Activities.

PubMed

Torres-Naranjo, María; Suárez, Alirica; Gilardoni, Gianluca; Cartuche, Luis; Flores, Paola; Morocho, Vladimir

2016-11-02

The phytochemical investigation of Muehlenbeckia tamnifolia , collected in Loja-Ecuador, led to the isolation of nine known compounds identified as: lupeol acetate ( 1 ); cis - p -coumaric acid ( 2 ); lupeol ( 3 ); β-sitosterol ( 4 ) trans - p -coumaric acid ( 5 ); linoleic acid ( 6 ) (+)-catechin ( 7 ); afzelin ( 8 ) and quercitrin ( 9 ). The structures of the isolated compounds were determined based on analysis of NMR and MS data, as well as comparison with the literature. The hypoglycemic activity of crude extracts and isolated compounds was assessed by the ability to inhibit α-amylase and α-glucosidase enzymes. The hexane extract showed weak inhibitory activity on α-amylase, with an IC 50 value of 625 µg·mL -1 , while the other extracts and isolated compounds were inactive at the maximum dose tested. The results on α-glucosidase showed more favorable effects; the hexanic and methanolic extracts exhibited a strong inhibitory activity with IC 50 values of 48.22 µg·mL -1 and 19.22 µg·mL -1 , respectively. Four of the nine isolated compounds exhibited strong inhibitory activity with IC 50 values below 8 µM, much higher than acarbose (377 uM). Linoleic acid was the most potent compound (IC 50 = 0.42 µM) followed by afzelin, (+)-catechin and quercitrin.

Rhodamine B conjugates of triterpenoic acids are cytotoxic mitocans even at nanomolar concentrations.

PubMed

Sommerwerk, Sven; Heller, Lucie; Kerzig, Christoph; Kramell, Annemarie E; Csuk, René

2017-02-15

Triterpenoic acids 1-6 exhibited very low or no cytotoxicity at all, but their corresponding 2,3-di-O-acetyl-piperazinyl amides 13-18 showed low EC 50 values for several human tumor cell lines. Their cytotoxicity, however, was also high for the non-malignant mouse fibroblasts NIH 3T3. A significant improvement was achieved by preparing the rhodamine B derivatives 19-24. While rhodamine B is not cytotoxic (up to a concentration of 30μM - cut-off of the assay), the triterpenoid piperazine-spacered rhodamine B derivatives were cytotoxic in nano-molar concentration. Compound 24 (a diacetylated maslinic acid derivative) was most toxic for several human tumor cell lines but less toxic for mouse fibroblasts NIH 3T3. Staining and double-staining experiments revealed 24 to act as a mitocan. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Cytotoxicity evaluation of a new set of 2-aminobenzo[de]iso-quinoline-1,3-diones.

PubMed

Al-Salahi, Rashad; Alswaidan, Ibrahim; Marzouk, Mohamed

2014-12-04

A new series of 2-amino-benzo[de]isoquinoline-1,3-diones was synthesized and fully characterized in our previous paper. Here, their cytotoxic effects have been evaluated in vitro in relation to colon HCT-116, hepatocellular Hep-G2 and breast MCF-7 cancer cell lines, using a crystal violet viability assay. The IC50-values of the target compounds are reported in µg/mL, using doxorubicin as a reference drug. The findings revealed that compounds 14, 15, 16, 21 and 22 had significant cytotoxic effects against HCT-116, MCF-7 and Hep-G2 cell lines. Their IC50 values ranged between 1.3 and 8.3 μg/mL in relation to doxorubicin (IC50 ≈ 0.45-0.89 μg/mL). Therefore, these compounds could be used as templates for furthering the development and design of more potent antitumor agents through structural modification.

Discovery of Nanomolar Dengue and West Nile Virus Protease Inhibitors Containing a 4-Benzyloxyphenylglycine Residue.

PubMed

Behnam, Mira A M; Graf, Dominik; Bartenschlager, Ralf; Zlotos, Darius P; Klein, Christian D

2015-12-10

The dengue virus (DENV) and West Nile Virus (WNV) NS2B-NS3 proteases are attractive targets for the development of dual-acting therapeutics against these arboviral pathogens. We present the synthesis and extensive biological evaluation of inhibitors that contain benzyl ethers of 4-hydroxyphenylglycine as non-natural peptidic building blocks synthesized via a copper-complex intermediate. A three-step optimization strategy, beginning with fragment growth of the C-terminal 4-hydroxyphenylglycine to the benzyloxy ether, followed by C- and N-terminal optimization, and finally fragment merging generated compounds with in vitro affinities in the low nanomolar range. The most promising derivative reached Ki values of 12 nM at the DENV-2 and 39 nM at the WNV proteases. Several of the newly discovered protease inhibitors yielded a significant reduction of dengue and West Nile virus titers in cell-based assays of virus replication, with an EC50 value of 3.4 μM at DENV-2 and 15.5 μM at WNV for the most active analogue.

Novel ciprofloxacin hybrids using biology oriented drug synthesis (BIODS) approach: Anticancer activity, effects on cell cycle profile, caspase-3 mediated apoptosis, topoisomerase II inhibition, and antibacterial activity.

PubMed

Kassab, Asmaa E; Gedawy, Ehab M

2018-04-25

As we are interested in synthetizing biologically active leads with dual anticancer and antibacterial activity, we adopted biology oriented drug synthesis (BIODS) strategy to synthesize a series of novel ciprofloxacin (CP) hybrids. The National Cancer Institute (USA) selected seventeen newly synthesized compounds for anticancer evaluation against 59 different human tumor cell lines. Five compounds 3e, 3f, 3h, 3o and 3p were further studied through determination of IC 50 values against the most sensitive cancer cell lines. In vitro results showed that the five compounds exhibited potent anticancer activity against test cell lines in nanomolar to micromolar range, with IC 50 values between 0.72 and 4.92 μM, which was 9 to1.5 folds more potent than doxorubicin. In this study, two promising potent anticancer CP hybrids, 3f and 3o, were identified. The anti-proliferative activity of these compounds appears to correlate well with their ability to inhibit Topo II (IC 50  = 0.58 and 0.86 μM). It is worth mentioning that compound 3f was 6 folds more potent than doxorubicin, 5 folds more potent than amsacrine and 1.5 folds more potent than etoposide. At the same time, compound 3o showed 4 folds more inhibitory activity against Topo II than doxorubicin, 3 folds more potent than amsacrine and almost equipotent activity to etoposide. Activation of damage response pathway of the DNA leads to cell cycle arrest at G2/M phase, accumulation of cells in pre-G1 phase and annexin-V and propidium iodide staining, indicating that cell death proceeds through an apoptotic mechanism. Moreover, compounds 3f and 3o showed potent pro-apoptotic effect through induction of the intrinsic mitochondrial pathway of apoptosis. This mechanistic pathway was confirmed by a significant increase in the level of active caspase-3 compared to control. This observation may indicate that both CP hybrids can chelate with zinc, a powerful inhibitor of procaspase-3 enzymatic activity, so procaspase-3 may process itself to the active form. The synthesized CP derivatives were tested for their in vitro antibacterial activity against Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa strains. The results proved that all of the test compounds have shown good to excellent antibacterial activity, as compared to its parent molecule ciprofloxacin. Compounds 2, 3b, 3k, 3l, 3m, 3p, 5a, 5b, 5d and 5e exhibited equipotent or comparable activity to ciprofloxacin against the test strains. Compounds 3p and 5a were more potent than ciprofloxacin against Pseudomonas aeruginosa, a common organism causing infections in granulocytopenic cancer patients. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Three new triterpenoids from Ganoderma theaecolum.

PubMed

Liu, Li-Ying; Yan, Zheng; Kang, Jie; Chen, Ruo-Yun; Yu, De-Quan

2017-09-01

Three new triterpenoids (1-3), together with four known triterpenoids (4-7), were isolated from the fruiting bodies of Ganoderma theaecolum. Their structures were elucidated on the basis of their spectroscopic data and chemical evidence. Compounds 4 and 6 exhibited antitumor activities against H460 cells with IC 50 values of 22.4 and 43.1 μM, respectively. And the cytotoxic activities of compounds 4 and 5 against MDA-MB-231 cancer cell lines were assayed with IC 50 values of 49.1 and 75.8 μM, respectively.

Design, synthesis, crystallization and biological evaluation of new symmetrical biscationic compounds as selective inhibitors of human Choline Kinase α1 (ChoKα1).

PubMed

Schiaffino-Ortega, Santiago; Baglioni, Eleonora; Mariotto, Elena; Bortolozzi, Roberta; Serrán-Aguilera, Lucía; Ríos-Marco, Pablo; Carrasco-Jimenez, M Paz; Gallo, Miguel A; Hurtado-Guerrero, Ramon; Marco, Carmen; Basso, Giuseppe; Viola, Giampietro; Entrena, Antonio; López-Cara, Luisa Carlota

2016-03-31

A novel family of compounds derivative of 1,1'-(((ethane-1,2-diylbis(oxy))bis(4,1-phenylene))bis(methylene))-bispyridinium or -bisquinolinium bromide (10a-l) containing a pair of oxygen atoms in the spacer of the linker between the biscationic moieties, were synthesized and evaluated as inhibitors of choline kinase against a panel of cancer-cell lines. The most promising compounds in this series were 1,1'-(((ethane-1,2-diylbis(oxy))bis(4,1-phenylene))bis(methylene))bis(4-(dimethylamino)pyridinium) bromide (10a) and 1,1'-(((ethane-1,2-diylbis(oxy))bis(4,1-phenylene))bis(methylene))-bis(7-chloro-4-(pyrrolidin-1-yl)quinolinium) bromide (10l), which inhibit human choline kinase (ChoKα1) with IC50 of 1.0 and 0.92 μM, respectively, in a range similar to that of the previously reported biscationic compounds MN58b and RSM932A. Our compounds show greater antiproliferative activities than do the reference compounds, with unprecedented values of GI50 in the nanomolar range for several of the cancer-cell lines assayed, and more importantly they present low toxicity in non-tumoral cell lines, suggesting a cancer-cell-selective antiproliferative activity. Docking studies predict that the compounds interact with the choline-binding site in agreement with the binding mode of most previously reported biscationic compounds. Moreover, the crystal structure of ChoKα1 with compound 10a reveals that this compound binds to the choline-binding site and mimics HC-3 binding mode as never before.

Ibrutinib (ImbruvicaTM) potently inhibits ErbB receptor phosphorylation and cell viability of ErbB2-positive breast cancer cells.

PubMed

Grabinski, Nicole; Ewald, Florian

2014-12-01

Ibrutinib (formerly PCI-32765) is a specific, irreversible, and potent inhibitor of Burton's tyrosine kinase (BTK) developed for the treatment of several forms of blood cancer. It is now an FDA-approved drug marketed under the name Imbruvica(TM) (Pharmacyclics, Inc.) and successfully used as an orally administered second-line drug in the treatment of mantle cell lymphoma. Since BTK is predominantly expressed in hematopoietic cells, the sensitivity of solid tumor cells to Ibrutinib has not been analyzed. In this study, we determined the effect of Ibrutinib on breast cancer cells. We demonstrate that Ibrutinib efficiently reduces the phosphorylation of the receptor tyrosine kinases ErbB1, ErbB2 and ErbB3, thereby suppressing AKT and MAPK signaling in ErbB2-positive (ErbB2+) breast cancer cell lines. Treatment with Ibrutinib significantly reduced the viability of ErbB2+ cell lines with IC50 values at nanomolar concentrations, suggesting therapeutic potential of Ibrutinib in breast cancer. Combined treatment with Ibrutinib and the dual PI3K/mTOR inhibitor BEZ235 synergistically reduces cell viability of ErbB2+ breast cancer cells. Combination indices below 0.25 at 50% inhibition of cell viability were determined by the Chou-Talalay method. Therefore, the combination of Ibrutinib and canonical PI3K pathway inhibitors could be a new and effective approach in the treatment of breast cancer with activated ErbB receptors. Ibrutinib could thus become a valuable component of targeted therapy in aggressive ErbB2+ breast cancer.

Inhibition of the acetoclastic methanogenic activity by phenol and alkyl phenols.

PubMed

Olguin-Lora, P; Puig-Grajales, L; Razo-Flores, E

2003-08-01

Chemical and petrochemical industries are important sources of aromatic pollutants. Petrochemical processes like caustic washing of middle distillates produce the spent caustic liquors highly concentrated in phenol and alkyl phenols. The anaerobic technology is considered a feasible strategy for petrochemical wastewater pre-treatment although high concentrations of phenol could limit its efficiency. The goal of this work was to determine the toxicity of both selected alkyl phenols and a synthetic "spent-caustic phenols mixture" on the acetoclastic Specific Methanogenic Activity (SMA) of unadapted and phenol-adapted granular sludge. Alkyl phenols were responsible for 50% (IC50) and 100% (IC100) inhibition of the SMA at concentrations ranging from 1.6 to 5.0 mM and from 4.1 to 27.5 mM, respectively, for un-adapted granular sludge. In the case of phenol-adapted granular sludge, the inhibitory concentrations ranged from 1.7 to 14.9 mM and from 4.0 to 83.0 for IC50 and IC100, respectively, highlighting the impact of sludge acclimation. The inhibition produced by 2-ethylphenol was more acute compared to phenol and was not reduced by the phenol acclimation process. The IC50 and IC100 values obtained for the synthetic "spent-caustic phenols mixture" were 9.5 mM and 88.4 mM, respectively. The inhibitory concentrations of phenol compounds were closely correlated with compound apolarity (log P), indicating that the lipophilic character of the tested compounds was responsible for their methanogenic toxicity. An inhibition model is confirmed to estimate the IC50 and IC100.

A SYBR Green 1-based in vitro test of susceptibility of Ghanaian Plasmodium falciparum clinical isolates to a panel of anti-malarial drugs.

PubMed

Quashie, Neils B; Duah, Nancy O; Abuaku, Benjamin; Quaye, Lydia; Ayanful-Torgby, Ruth; Akwoviah, George A; Kweku, Margaret; Johnson, Jacob D; Lucchi, Naomi W; Udhayakumar, Venkatachalam; Duplessis, Christopher; Kronmann, Karl C; Koram, Kwadwo A

2013-12-17

Based on report of declining efficacy of chloroquine, Ghana shifted to the use of artemisinin-based combination therapy (ACT) in 2005 as the first-line anti-malarial drug. Since then, there has not been any major evaluation of the efficacy of anti-malarial drugs in Ghana in vitro. The sensitivity of Ghanaian Plasmodium falciparum isolates to anti-malarial drugs was, therefore, assessed and the data compared with that obtained prior to the change in the malaria treatment policy. A SYBR Green 1 fluorescent-based in vitro drug sensitivity assay was used to assess the susceptibility of clinical isolates of P. falciparum to a panel of 12 anti-malarial drugs in three distinct eco-epidemiological zones in Ghana. The isolates were obtained from children visiting health facilities in sentinel sites located in Hohoe, Navrongo and Cape Coast municipalities. The concentration of anti-malarial drug inhibiting parasite growth by 50% (IC50) for each drug was estimated using the online program, ICEstimator. Pooled results from all the sentinel sites indicated geometric mean IC50 values of 1.60, 3.80, 4.00, 4.56, 5.20, 6.11, 10.12, 28.32, 31.56, 93.60, 107.20, and 8952.50 nM for atovaquone, artesunate, dihydroartemisin, artemether, lumefantrine, amodiaquine, mefloquine, piperaquine, chloroquine, tafenoquine, quinine, and doxycycline, respectively. With reference to the literature threshold value indicative of resistance, the parasites showed resistance to all the test drugs except the artemisinin derivatives, atovaquone and to a lesser extent, lumefantrine. There was nearly a two-fold decrease in the IC50 value determined for chloroquine in this study compared to that determined in 2004 (57.56 nM). This observation is important, since it suggests a significant improvement in the efficacy of chloroquine, probably as a direct consequence of reduced drug pressure after cessation of its use. Compared to that measured prior to the change in treatment policy, significant elevation of artesunate IC50 value was observed. The results also suggest the existence of possible cross-resistance among some of the test drugs. Ghanaian P. falciparum isolates, to some extent, have become susceptible to chloroquine in vitro, however the increasing trend in artesunate IC50 value observed should be of concern. Continuous monitoring of ACT in Ghana is recommended.

In vitro cytotoxicity testing of 30 reference chemicals to predict acute human and animal toxicity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barile, F.A.; Arjun, S.; Borges, L.

1991-03-11

This study was conducted in cooperation with the Scandinavian Society of Cell Toxicology, as part of the Multicenter Evaluation for In Vitro Cytotoxicity (MEIC), and was designed to develop an in vitro model for predicting acute human and animal toxicity. The technique relies on the ability of cultured transformed rat lung epithelial cells (L2) to incorporate radiolabled amino acids into newly synthesized proteins in the absence or presence of increasing doses of the test chemical, during a 24-hr incubation. IC50 values were extrapolated from the dose-response curves after linear regression analysis. Human toxic blood concentrations estimated from rodent LD50 valuesmore » suggest that our experimental IC50's are in close correlation with the former. Validation of the data by the MEIC committee shows that our IC50 values predicted human lethal dosage as efficient as rodent LD50's. It is anticipated that this and related procedures may supplement or replace currently used animal protocols for predicting human toxicity.« less

Synthesis and Antiplasmodial Activity of Novel Chloroquine Analogues with Bulky Basic Side Chains.

PubMed

Tasso, Bruno; Novelli, Federica; Tonelli, Michele; Barteselli, Anna; Basilico, Nicoletta; Parapini, Silvia; Taramelli, Donatella; Sparatore, Anna; Sparatore, Fabio

2015-09-01

Chloroquine is commonly used in the treatment and prevention of malaria, but Plasmodium falciparum, the main species responsible for malaria-related deaths, has developed resistance against this drug. Twenty-seven novel chloroquine (CQ) analogues characterized by a side chain terminated with a bulky basic head group, i.e., octahydro-2H-quinolizine and 1,2,3,4,5,6-hexahydro-1,5-methano-8H-pyrido[1,2-a][1,5]diazocin-8-one, were synthesized and tested for activity against D-10 (CQ-susceptible) and W-2 (CQ-resistant) strains of P. falciparum. Most compounds were found to be active against both strains with nanomolar or sub-micromolar IC50 values. Eleven compounds were found to be 2.7- to 13.4-fold more potent than CQ against the W-2 strain; among them, four cytisine derivatives appear to be of particular interest, as they combine high potency with low cytotoxicity against two human cell lines (HMEC-1 and HepG2) along with easier synthetic accessibility. Replacement of the 4-NH group with a sulfur bridge maintained antiplasmodial activity at a lower level, but produced an improvement in the resistance factor. These compounds warrant further investigation as potential drugs for use in the fight against malaria. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

(4-Methoxyphenyl)(3,4,5-trimethoxyphenyl)methanone inhibits tubulin polymerization, induces G{sub 2}/M arrest, and triggers apoptosis in human leukemia HL-60 cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Magalhães, Hemerson I.F.; Centro de Ciências da Saúde, Departamento de Ciências Farmacêuticas, Universidade Federal da Paraíba, João Pessoa, Paraíba; Wilke, Diego V.

2013-10-01

(4-Methoxyphenyl)(3,4,5-trimethoxyphenyl)methanone (PHT) is a known cytotoxic compound belonging to the phenstatin family. However, the exact mechanism of action of PHT-induced cell death remains to be determined. The aim of this study was to investigate the mechanisms underlying PHT-induced cytotoxicity. We found that PHT displayed potent cytotoxicity in different tumor cell lines, showing IC{sub 50} values in the nanomolar range. Cell cycle arrest in G{sub 2}/M phase along with the augmented metaphase cells was found. Cells treated with PHT also showed typical hallmarks of apoptosis such as cell shrinkage, chromatin condensation, phosphatidylserine exposure, increase of the caspase 3/7 and 8 activation,more » loss of mitochondrial membrane potential, and internucleosomal DNA fragmentation without affecting membrane integrity. Studies conducted with isolated tubulin and docking models confirmed that PHT binds to the colchicine site and interferes in the polymerization of microtubules. These results demonstrated that PHT inhibits tubulin polymerization, arrests cancer cells in G{sub 2}/M phase of the cell cycle, and induces their apoptosis, exhibiting promising anticancer therapeutic potential. - Highlights: • PHT inhibits tubulin polymerization. • PHT arrests cancer cells in G{sub 2}/M phase of the cell cycle. • PHT induces caspase-dependent apoptosis.« less

The Aurora kinase inhibitor CCT137690 downregulates MYCN and sensitizes MYCN-amplified neuroblastoma in vivo

PubMed Central

Faisal, Amir; Vaughan, Lynsey; Bavetsias, Vassilios; Sun, Chongbo; Atrash, Butrus; Avery, Sian; Jamin, Yann; Robinson, Simon P.; Workman, Paul; Blagg, Julian; Raynaud, Florence I.; Eccles, Suzanne A.; Chesler, Louis; Linardopoulos, Spiros

2015-01-01

The Aurora kinases regulate key stages of mitosis including centrosome maturation, spindle assembly, chromosome segregation and cytokinesis. Aurora A and B overexpression has also been associated with various human cancers and as such, they have been extensively studied as novel anti-mitotic drug targets. Here we characterise the Aurora kinase inhibitor CCT137690, a highly selective, orally bioavailable imidazo[4,5-b]pyridine derivative that inhibits Aurora A and B kinases with low nanomolar IC50 values in both biochemical and cellular assays and exhibits anti-proliferative activity against a wide range of human solid tumour cell lines. CCT137690 efficiently inhibits histone H3 and TACC3 phosphorylation (Aurora B and Aurora A substrates, respectively) in HCT116 and HeLa cells. Continuous exposure of tumour cells to the inhibitor causes multipolar spindle formation, chromosome misalignment, polyploidy and apoptosis. This is accompanied by p53/p21/BAX induction, thymidine kinase 1 (TK1) downregulation and PARP cleavage. Furthermore, CCT137690 treatment of MYCN-amplified neuroblastoma cell lines inhibits cell proliferation and decreases MYCN protein expression. Importantly, in a transgenic mouse model of neuroblastoma (TH-MYCN) that overexpresses MYCN protein and is predisposed to spontaneous neuroblastoma formation, this compound significantly inhibits tumour growth. The potent preclinical activity of CCT137690 suggests that this inhibitor may benefit patients with MYCN amplified neuroblastoma. PMID:21885865

Synthesis of cyclic 1,9-acetal derivatives of forskolin and their bioactivity evaluation.

PubMed

Ponnam, Devendar; Shilpi, Singh; Srinivas, K V N S; Suiab, Luqman; Alam, Sarfaraz; Amtul, Zehra; Arigari, Niranjan Kumar; Jonnala, Kotesh Kumar; Siddiqui, Lubna; Dubey, Vijaya; Tiwari, Ashok Kumar; Balasubramanian, Sridhar; Khan, Feroz

2014-11-24

A new series of 1,9-acetals of forskolin were synthesized by treating with aromatic and aliphatic aldehydes using Ceric ammonium nitrate as catalyst and evaluated for anticancer and α-glucosidase inhibition activities. Among the synthesized compounds 2a, 2b and 3a showed potential cytotoxic activity towards human cancer cell lines MCF-7 (Human Breast Adenocarcinoma), MDA-MB (Human Breast Carcinoma), HeLa (Human Cervix Adenocarcinoma), A498 (Human Kidney Carcinoma), K562 (Human Erythromyeloblastoid leukemia), SH-SY5Y (Human Neuroblastoma), Hek293 (Human Embryonic Kidney) and WRL68 (Human Hepatic) with IC50 values ranging between 0.95 and 47.96 μg/ml. Osmotic fragility test revealed compound 3a as non-toxic to human erythrocytes at the tested concentrations of 50 and 100 μg/ml. Compounds 1g (IC50 value 0.76 μg/ml) and 1p (IC50 value 0.74 μg/ml) significantly inhibited α-glucosidase in in vitro system. In silico based docking, ADME and toxicity risk assessment studies also showed discernible α-glucosidase activity for compounds 1g, 1p compared to standard acarbose. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Inhibition properties of propolis extracts to some clinically important enzymes.

PubMed

Baltas, Nimet; Yildiz, Oktay; Kolayli, Sevgi

2016-01-01

The present study was conducted to envisage inhibition effects of propolis on the crucial enzymes, urease, xanthine oxidase (XO) and acetylcholinesterase (AChE). Some of the antioxidant properties of the propolis samples were determined using the total phenolic content (TPE) and total flavonoids in the eight different ethanolic propolis extracts (EPE) samples. Inhibition values of the enzymes were expressed as inhibition concentration (IC 50 ; mg/mL or μg/mL) causing 50% inhibition of the enzymes with donepezil, acetohydroxamic acid and allopurinol as reference inhibitors. All the propolis extracts exhibited variable inhibition effects on these enzymes, but the higher the phenolic contents the lower the inhibitions values (IC 50 = 0.074 to 1.560 mg/mL). IC 50 values of the P5 propolis sample having the highest TPE, obtained from Zonguldak, for AChE, urease and XO were 0.081 ± 0.009, 0.080 ± 0.006 and 0.074 ± 0.011 μg/mL, respectively. The EPE proved to be a good source of inhibitor agents that can be used as natural inhibitors to serve human health.

Large scale screening of commonly used Iranian traditional medicinal plants against urease activity

PubMed Central

2012-01-01

Background and purpose of the study H. pylori infection is an important etiologic impetus usually leading to gastric disease and urease enzyme is the most crucial role is to protect the bacteria in the acidic environment of the stomach. Then urease inhibitors would increase sensitivity of the bacteria in acidic medium. Methods 137 Iranian traditional medicinal plants were examined against Jack bean urease activity by Berthelot reaction. Each herb was extracted using 50% aqueous methanol. The more effective extracts were further tested and their IC50 values were determined. Results 37 plants out of the 137 crude extracts revealed strong urease inhibitory activity (more than 70% inhibition against urease activity at 10 mg/ml concentration). Nine of the whole studied plants crude extracts were found as the most effective with IC50 values less than 500 μg/ml including; Rheum ribes, Sambucus ebulus, Pistachia lentiscus, Myrtus communis, Areca catechu, Citrus aurantifolia, Myristica fragrans, Cinnamomum zeylanicum and Nicotiana tabacum. Conclusions The most potent urease inhibitory was observed for Sambucus ebulus and Rheum ribes extracts with IC50 values of 57 and 92 μg/ml, respectively. PMID:23351780

Positional isomerism markedly affects the growth inhibition of colon cancer cells by NOSH-aspirin: COX inhibition and modeling.

PubMed

Vannini, Federica; Chattopadhyay, Mitali; Kodela, Ravinder; Rao, Praveen P N; Kashfi, Khosrow

2015-12-01

We recently reported the synthesis of NOSH-aspirin, a novel hybrid that releases both nitric oxide (NO) and hydrogen sulfide (H2S). In NOSH-aspirin, the two moieties that release NO and H2S are covalently linked at the 1, 2 positions of acetyl salicylic acid, i.e. ortho-NOSH-aspirin (o-NOSH-aspirin). In the present study, we compared the effects of the positional isomers of NOSH-ASA (o-NOSH-aspirin, m-NOSH-aspirin and p-NOSH-aspirin) to that of aspirin on growth of HT-29 and HCT 15 colon cancer cells, belonging to the same histological subtype, but with different expression of cyclooxygenase (COX) enzymes; HT-29 express both COX-1 and COX-2, whereas HCT 15 is COX-null. We also analyzed the effect of these compounds on proliferation and apoptosis in HT-29 cells. Since the parent compound aspirin, inhibits both COX-1 and COX-2, we also evaluated the effects of these compounds on COX-1 and COX-2 enzyme activities and also performed modeling of the interactions between the positional isomers of NOSH-aspirin and COX-1 and COX-2 enzymes. We observed that the three positional isomers of NOSH aspirin inhibited the growth of both colon cancer cell lines with IC50s in the nano-molar range. In particular in HT-29 cells the IC50s for growth inhibition were: o-NOSH-ASA, 0.04±0.011 µM; m-NOSH-ASA, 0.24±0.11 µM; p-NOSH-ASA, 0.46±0.17 µM; and in HCT 15 cells the IC50s for o-NOSH-ASA, m-NOSH-ASA, and p-NOSH-ASA were 0.062 ±0.006 µM, 0.092±0.004 µM, and 0.37±0.04 µM, respectively. The IC50 for aspirin in both cell lines was >5mM at 24h. The reduction of cell growth appeared to be mediated through inhibition of proliferation, and induction of apoptosis. All 3 positional isomers of NOSH-aspirin preferentially inhibited COX-1 over COX-2. These results suggest that the three positional isomers of NOSH-aspirin have the same biological actions, but that o-NOSH-ASA displayed the strongest anti-neoplastic potential. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Antileishmanial, antimalarial and antimicrobial activities of the extract and isolated compounds from Austroplenckia populnea (Celastraceae).

PubMed

Andrade, Sérgio F; da Silva Filho, Ademar A; de O Resende, Dimas; Silva, Márcio L A; Cunha, Wilson R; Nanayakkara, N P Dhammika; Bastos, Jairo Kenupp

2008-01-01

Austroplenckia populnea (Celastraceae), known as "marmelinho do campo", is used in Brazilian folk medicine as antimicrobial, anti-inflammatory, and antitumoural agent. The aim of the present work was to evaluate the antimicrobial, antileishmanial and antimalarial activities of the crude hydroalcoholic extract of A. populnea (CHE) and some of its isolated compounds. The phytochemical study of the CHE was carried out affording the isolation of methyl populnoate (1), populnoic acid (2), and stigmast-5-en-3-O-beta-(D-glucopyranoside) (3). This is the first time that the presence of compound 3 in A. populnea is reported. The results showed that the CHE presents antifungal and antibacterial activities, especially against Candida glabrata and Candida albicans, for which the CHE showed IC50 values of 0.7 microg mL(-1) and 5.5 microg mL(-1), respectively, while amphotericin B showed an IC50 value of 0.1 microg mL(-1) against both microorganisms. Compounds 1-3 were inactive against all tested microorganisms. In the antileishmanial activity test against Leishmania donovani, the CHE showed an IC50 value of 52 microg mL(-1), while compounds 2 and 3 displayed an IC50 value of 18 microg mL(-1) In the antimalarial assay against Plasmodium falciparum (D6 and W2 clones), it was observed that all evaluated samples were inactive. In order to compare the effect on the parasites with the toxicity to mammalian cells, the cytotoxicity activity of the isolated compounds was evaluated against Vero cells, showing that all evaluated samples exhibited no cytotoxicity at the maximum dose tested.

Classification of drug molecules considering their IC50 values using mixed-integer linear programming based hyper-boxes method.

PubMed

Armutlu, Pelin; Ozdemir, Muhittin E; Uney-Yuksektepe, Fadime; Kavakli, I Halil; Turkay, Metin

2008-10-03

A priori analysis of the activity of drugs on the target protein by computational approaches can be useful in narrowing down drug candidates for further experimental tests. Currently, there are a large number of computational methods that predict the activity of drugs on proteins. In this study, we approach the activity prediction problem as a classification problem and, we aim to improve the classification accuracy by introducing an algorithm that combines partial least squares regression with mixed-integer programming based hyper-boxes classification method, where drug molecules are classified as low active or high active regarding their binding activity (IC50 values) on target proteins. We also aim to determine the most significant molecular descriptors for the drug molecules. We first apply our approach by analyzing the activities of widely known inhibitor datasets including Acetylcholinesterase (ACHE), Benzodiazepine Receptor (BZR), Dihydrofolate Reductase (DHFR), Cyclooxygenase-2 (COX-2) with known IC50 values. The results at this stage proved that our approach consistently gives better classification accuracies compared to 63 other reported classification methods such as SVM, Naïve Bayes, where we were able to predict the experimentally determined IC50 values with a worst case accuracy of 96%. To further test applicability of this approach we first created dataset for Cytochrome P450 C17 inhibitors and then predicted their activities with 100% accuracy. Our results indicate that this approach can be utilized to predict the inhibitory effects of inhibitors based on their molecular descriptors. This approach will not only enhance drug discovery process, but also save time and resources committed.

Synthesis and biological evaluation of a series of dithiocarbamates as new cholinesterase inhibitors.

PubMed

Altıntop, Mehlika D; Gurkan-Alp, A Selen; Ozkay, Yusuf; Kaplancıklı, Zafer A

2013-08-01

In the present paper, a novel series of dithiocarbamates was synthesized via the treatment of 4-(trifluoromethyl)benzyl chloride with appropriate sodium salts of N,N-disubstituted dithiocarbamic acids. The chemical structures of the compounds were elucidated by (1) H NMR, mass spectral data, and elemental analyses. Each derivative was evaluated for its ability to inhibit acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) using a modification of Ellman's spectrophotometric method. The most potent AChE inhibitor was found as compound 2g (IC50  = 0.53 ± 0.001 µM) followed by compounds 2f (IC50  = 0.74 ± 0.001 µM) and 2j (IC50  = 0.89 ± 0.002 µM) when compared with donepezil (IC50  = 0.048 ± 0.001 µM). Compounds 2f and 2g were more effective than donepezil (IC50  = 7.88 ± 0.52 µM) on BuChE inhibition. Compounds 2f and 2g exhibited the inhibitory effect on BuChE with IC50 values of 1.39 ± 0.041 and 3.64 ± 0.072 µM, respectively. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Antioxidant activity and total phenolic content of ethanolic extract of Caesalpinia bonducella seeds.

PubMed

Shukla, Shruti; Mehta, Archana; John, Jinu; Singh, Siddharth; Mehta, Pradeep; Vyas, Suresh Prasad

2009-08-01

The aim of this study was to assess the in vitro potential of ethanolic extract of Caesalpinia bonducella seeds as a natural antioxidant. The DPPH activity of the extract (20, 40, 50, 100 and 200 microg/ml) was increased in a dose dependent manner, which was found in the range of 38.93-74.77% as compared to ascorbic acid (64.26-82.58%). The IC(50) values of ethanolic extract and ascorbic acid in DPPH radical scavenging assay were obtained to be 74.73 and 26.68 microg/ml, respectively. The ethanolic extract was also found to scavenge the superoxide generated by EDTA/NBT system. Measurement of total phenolic content of the ethanolic extract of C. bonducella was achieved using Folin-Ciocalteau reagent containing 62.50mg/g of phenolic content, which was found significantly higher when compared to reference standard gallic acid. The ethanolic extract also inhibited the hydroxyl radical, nitric oxide, superoxide anions with IC(50) values of 109.85, 102.65 and 89.84 microg/ml, respectively. However, the IC(50) values for the standard ascorbic acid were noted to be 70.79, 65.98 and 36.68 microg/ml respectively. The results obtained in this study clearly indicate that C. bonducella has a significant potential to use as a natural antioxidant agent.

Abietane-Type Diterpenoid Amides with Highly Potent and Selective Activity against Leishmania donovani and Trypanosoma cruzi.

PubMed

Pirttimaa, Minni; Nasereddin, Abedelmajeed; Kopelyanskiy, Dmitry; Kaiser, Marcel; Yli-Kauhaluoma, Jari; Oksman-Caldentey, Kirsi-Marja; Brun, Reto; Jaffe, Charles L; Moreira, Vânia M; Alakurtti, Sami

2016-02-26

Dehydroabietylamine (1) was used as a starting material to synthesize a small library of dehydroabietyl amides by simple and facile methods, and their activities against two disease-causing trypanosomatids, namely, Leishmania donovani and Trypanosoma cruzi, were assayed. The most potent compound, 10, an amide of dehydroabietylamine and acrylic acid, was found to be highly potent against these parasites, displaying an IC50 value of 0.37 μM against L. donovani axenic amastigotes and an outstanding selectivity index of 63. Moreover, compound 10 fully inhibited the growth of intracellular amastigotes in Leishmania donovani-infected human macrophages with a low IC50 value of 0.06 μM. This compound was also highly effective against T. cruzi amastigotes residing in L6 cells with an IC50 value of 0.6 μM and high selectivity index of 58, being 3.5 times more potent than the reference compound benznidazole. The potent activity of this compound and its relatively low cytotoxicity make it attractive for further development in pursuit of better drugs for patients suffering from leishmaniasis and Chagas disease.

Preparation and characterization of novel bioactive peptides responsible for angiotensin I-converting enzyme inhibition from wheat germ.

PubMed

Matsui, T; Li, C H; Osajima, Y

1999-07-01

Reported is the preparation of wheat germ (WG) hydrolyzate with potent angiotensin I-converting enzyme (ACE) inhibitory activity, and the characterization of peptides responsible for ACE inhibition. Successful hydrolyzate with the most potent ACE inhibitory activity was obtained by 0.5 wt.%-8 h Bacillus licheniformis alkaline protease hydrolysis after 3.0 wt.%-3 h alpha-amylase treatment of defatted WG (IC50; 0.37 mg protein ml(-1)). The activity of WG hydrolyzate was markedly increased by ODS and subsequent AG50W purifications (IC50; 0.018 mg protein ml(-1)). As a result of isolations by high performance liquid chromatographies, 16 peptides with the IC50 value of less than 20 microM, composed of 2-7 amino acid residues were identified from the WG hydrolyzate. Judging from the high content (260 mg in 100 g of AG50W fraction) and powerful ACE inhibitory activity (IC50; 0.48 microM), Ile-Val-Tyr was identified as a main contributor to the ACE inhibition of the hydrolyzate.

Lead toxicity to Lemna minor predicted using a metal speciation chemistry approach.

PubMed

Antunes, Paula M C; Kreager, Nancy J

2014-10-01

In the present study, predictive measures for Pb toxicity and Lemna minor were developed from bioassays with 7 surface waters having varied chemistries (0.5-12.5 mg/L dissolved organic carbon, pH of 5.4-8.3, and water hardness of 8-266 mg/L CaCO3 ). As expected based on water quality, 10%, 20%, and 50% inhibitory concentration (IC10, IC20, and IC50, respectively) values expressed as percent net root elongation (%NRE) varied widely (e.g., IC20s ranging from 306 nM to >6920 nM total dissolved Pb), with unbounded values limited by Pb solubility. In considering chemical speciation, %NRE variability was better explained when both Pb hydroxides and the free lead ion were defined as bioavailable (i.e., f{OH} ) and colloidal Fe(III)(OH)3 precipitates were permitted to form and sorb metals (using FeOx as the binding phase). Although cause and effect could not be established because of covariance with alkalinity (p = 0.08), water hardness correlated strongly (r(2)  = 0.998, p < 0.0001) with the concentration of total Pb in true solution ([Pb]T_True solution ). Using these correlations as the basis for predictions (i.e., [Pb]T_True solution vs water hardness and %NRE vs f{OH} ), IC20 and IC50 values produced were within a factor of 2.9 times and 2.2 times those measured, respectively. The results provide much needed effect data for L. minor and highlight the importance of chemical speciation in Pb-based risk assessments for aquatic macrophytes. © 2014 SETAC.

Mechanism of the effect of pH and biochar on the phytotoxicity of the weak acid herbicides imazethapyr and 2,4-D in soil to rice (Oryza sativa) and estimation by chemical methods.

PubMed

Liu, Kailin; He, Ying; Xu, Shiji; Hu, Lifeng; Luo, Kun; Liu, Xiangying; Liu, Min; Zhou, Xiaomao; Bai, Lianyang

2018-06-18

The existing form of an ionizable organic compound can simultaneously affect its soil adsorption and plant bioactivity. In this experiment, the adsorption and bioactivity of two weak acid herbicides (WAHs), imazethapyr and 2,4-D, were studied to explore the predominant mechanism by which the soil pH and the addition of biochar can influence the phytotoxicity of WAHs in soil. Then, the WAH concentration extracted by hollow fiber-based liquid-phase microextraction (C HF-LPME ), the in situ pore water concentration (C IPW ) and the added concentration (C AC ) were employed to estimate the phytotoxicity. The results showed that with increased pH from 5.5 to 8.5, the phytotoxicity of the WAHs to rice increased about 1-fold in the soil, but decreased in aqueous solutions, the IC 50 values for imazethapyr and 2,4-D at pH 5.0 were 3- and 2-fold higher than that at pH 8.0. In addition, the soil adsorption decreased, indicating that the adsorption process was the dominant factor for the variation of the phytotoxicity of the WAHs in the tested soil instead of the decreasing bioactivity. The concentration that inhibits plant growth by 50% (IC 50 ) calculated by the C AC in different pH and biochar soils ranged from 0.619 to 3.826 mg/kg for imazethapyr and 1.871-72.83 mg/kg for 2,4-D. The coefficient of variation (CV) of the IC 50 values reached 65.61% for imazethapyr and 130.0% for 2,4-D. However, when IC 50 was calculated by C IPW and C HF-LPME , the CVs of the IC 50 values decreased to 23.51% and 36.23% for imazethapyr and 40.21% and 50.93% for 2,4-D, respectively. These results suggested that C IPW and C HF-LPME may be more appropriate than C AC for estimating the phytotoxicity of WAHs. Copyright © 2018 Elsevier Inc. All rights reserved.

Novel synthetic kojic acid-methimazole derivatives inhibit mushroom tyrosinase and melanogenesis.

PubMed

Chen, Ming-Jen; Hung, Chih-Chuan; Chen, Yan-Ru; Lai, Shih-Ting; Chan, Chin-Feng

2016-12-01

In this study, two kojic acid-methimazole (2-mercapto-1-methylimidazole, MMI, 1) derivatives, 5-hydroxy-2-{[(1-methyl-1H-imidazol-2-yl)thio]methyl}-4H-pyran-4-one (compound 4) and 5-methoxy-2-{[(1-methyl-1H-imidazol-2-yl)thio]methyl}-4H-pyran-4-one (compound 5), were synthesized to examine their inhibitory kinetics on mushroom tyrosinase. Compound 4 exhibited a potent inhibitory effect on monophenolase activity in a dose-dependent manner, with an IC 50 value of 0.03 mM. On diphenolase activity, compound 4 exhibited a less inhibitory effect (IC 50  = 1.29 mM) but was stronger than kojic acid (IC 50  = 1.80 mM). Kinetic analysis indicated that compound 4 was both as a noncompetitive monophenolase and diphenolase inhibitor. By contrast, compound 5 exhibited no inhibitory effects on mushroom tyrosinase activity. The IC 50 value of compound 4 for the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity was 4.09 mM, being much higher than the IC 50 of compound 4 for inhibiting the tyrosinase activity. The results indicated that the antioxidant activity of compound 4 may be partly related to the potent inhibitory effect on mushroom tyrosinase. Compound 4 also exerted a potent inhibitory effect on intracellular melanin formation in B16/F10 murine melanoma cells, and caused no cytotoxicity. Furthermore, compound 4 induced no adverse effects on the Hen's egg test-chorioallantoic membrane (HET-CAM). Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

New efficient artemisinin derived agents against human leukemia cells, human cytomegalovirus and Plasmodium falciparum: 2nd generation 1,2,4-trioxane-ferrocene hybrids.

PubMed

Reiter, Christoph; Fröhlich, Tony; Zeino, Maen; Marschall, Manfred; Bahsi, Hanife; Leidenberger, Maria; Friedrich, Oliver; Kappes, Barbara; Hampel, Frank; Efferth, Thomas; Tsogoeva, Svetlana B

2015-06-05

In our ongoing search for highly active hybrid molecules exceeding their parent compounds in anticancer, antimalaria as well as antiviral activity and being an alternative to the standard drugs, we present the synthesis and biological investigations of 2nd generation 1,2,4-trioxane-ferrocene hybrids. In vitro tests against the CCRF-CEM leukemia cell line revealed di-1,2,4-trioxane-ferrocene hybrid 7 as the most active compound (IC50 of 0.01 μM). Regarding the activity against the multidrug resistant subline CEM/ADR5000, 1,2,4-trioxane-ferrocene hybrid 5 showed a remarkable activity (IC50 of 0.53 μM). Contrary to the antimalaria activity of hybrids 4-8 against Plasmodium falciparum 3D7 strain with slightly higher IC50 values (between 7.2 and 30.2 nM) than that of their parent compound DHA, hybrids 5-7 possessed very promising activity (IC50 values lower than 0.5 μM) against human cytomegalovirus (HCMV). The application of 1,2,4-trioxane-ferrocene hybrids against HCMV is unprecedented and demonstrated here for the first time. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Hypolipidemic and Antioxidant Properties of Hot Pepper Flower (Capsicum annuum L.).

PubMed

Marrelli, Mariangela; Menichini, Francesco; Conforti, Filomena

2016-09-01

At present, the various medical treatments of obesity involve side effects. The aim of the research is therefore to find natural compounds that have anti-obesity activity with minimum disadvantages. In this study, the hypolipidemic effect of hydroalcoholic extract of flowers from Capsicum annuum L. was examined through the evaluation of inhibition of pancreatic lipase. Antioxidant activity was assessed using different tests: 2,2-diphenyl-1-picrylhydrazyl (DPPH), nitric oxide (˙NO) and lipid peroxidation inhibition assays. Phytochemical analysis indicated that total phenolic and flavonoid content in the extract was 128.7 ± 4.5 mg chlorogenic acid equivalent/g of crude extract and 17.66 ± 0.11 mg of quercetin equivalent/g of crude extract, respectively. The extract inhibited pancreatic lipase with IC50 value equal to 3.54 ± 0.18 mg/ml. It also inhibited lipid peroxidation with IC50 value of 27.61 ± 2.25 μg/ml after 30 min of incubation and 41.69 ± 1.13 μg/ml after 60 min of incubation. The IC50 value of radical scavenging activity was 51.90 ± 2.03 μg/ml. The extract was also able to inhibit NO production (IC50 = of 264.3 ± 7.98 μg/ml) without showing any cytotoxic effect.

Novel Cholinesterase Inhibitors Based on O-Aromatic N,N-Disubstituted Carbamates and Thiocarbamates.

PubMed

Krátký, Martin; Štěpánková, Šárka; Vorčáková, Katarína; Švarcová, Markéta; Vinšová, Jarmila

2016-02-11

Based on the presence of carbamoyl moiety, twenty salicylanilide N,N-disubstituted (thio)carbamates were investigated using Ellman's method for their ability to inhibit acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). O-Aromatic (thio)carbamates exhibited weak to moderate inhibition of both cholinesterases with IC50 values within the range of 1.60 to 311.0 µM. IC50 values for BChE were mostly lower than those obtained for AChE; four derivatives showed distinct selectivity for BChE. All of the (thio)carbamates produced a stronger inhibition of AChE than rivastigmine, and five of them inhibited BChE more effectively than both established drugs rivastigmine and galantamine. In general, 5-chloro-2-hydroxy-N-[4-(trifluoromethyl)-phenyl]benzamide, 2-hydroxy-N-phenylbenzamide as well as N-methyl-N-phenyl carbamate derivatives led to the more potent inhibition. O-{4-Chloro-2-[(4-chlorophenyl)carbamoyl]phenyl} dimethylcarbamothioate was identified as the most effective AChE inhibitor (IC50 = 38.98 µM), while 2-(phenylcarbamoyl)phenyl diphenylcarbamate produced the lowest IC50 value for BChE (1.60 µM). Results from molecular docking studies suggest that carbamate compounds, especially N,N-diphenyl substituted representatives with considerable portion of aromatic moieties may work as non-covalent inhibitors displaying many interactions at peripheral anionic sites of both enzymes. Mild cytotoxicity for HepG2 cells and consequent satisfactory calculated selectivity indexes qualify several derivatives for further optimization.

Ecotoxicological responses of three ornamental herb species to cadmium.

PubMed

Liu, Zhouli; He, Xingyuan; Chen, Wei; Zhao, Mingzhu

2013-08-01

Cadmium is one of the most toxic elements. The ideal vegetal cover should be ensured by the selection of appropriate plant species for successful phytoremediation. In the present study, the ecotoxicological effects of Cd on the following 3 ornamental herbs were investigated: Italian ryegrass (Lolium multiflorum Lam.), white clover (Trifolium repens L.), and alfalfa (Medicago sativa L.). Based on the inhibition rate of seed germination, root and shoot elongation, early seedling growth, median inhibition concentration (IC50) values, and index of tolerance (IT) values, ecotoxicological indicators were determined. The results showed that 10 μM to 50 μM Cd had little effect on seed germination or root and shoot elongation of the 3 ornamental herbs (p > 0.01). With an increase in Cd concentrations, alfalfa (M. sativa) was the most sensitive to Cd toxicity in terms of seed germination and root elongation. Based on the IC50 of root elongation, Italian ryegrass (L. multiflorum) was the least sensitive to Cd. Based on the IC50 of seed germination and shoot elongation, white clover had the least sensitivity to Cd. Among the 3 ornamental herbs, based on the IC50 of seed germination and root and shoot elongation, alfalfa (M. sativa) was all the most sensitive plant. According to the index of tolerance, Italian ryegrass (L. multiflorum) was the most tolerant plant. Copyright © 2013 SETAC.

CYTOTOXIC, α-CHYMOTRYPSIN AND UREASE INHIBITION ACTIVITIES OF THE PLANT Heliotropium dasycarpum L.

PubMed

Ghaffari, Muhammad Abuzar; Chaudhary, Bashir Ahmed; Uzair, Muhammad; Ashfaq, Khuram

2016-01-01

The aim of this study was to investigate Cytotoxic, α-Chymotrypsin and Urease inhibition activities of the plant Heliotropium dasycarpum . Dichloromethane and methanol extracts of the plant were evaluated for cytotoxic, α-Chymotrypsin and Urease inhibition by using in vivo Brine Shrimp lethality bioassay and in vitro enzymatic inhibition assays respectively. The methanol extract of the plant exhibited significant cytotoxic activity. Out of 30 brine shrimp larvae, 2 (6%), 26 (86%) and 28 (93%) larvae were survived at concentration of 1000μg/ml, 100μg/ml and 10μg/ml respectively with LD50; 215.837. Similarly 21 (70%), 25 (83%), 29 (96%) larvae were survived of dichloromethane plant extract with LD50; 6170.64. The methanol and dichloromethane extract exhibited 10.50±0.18% and 41.51±0.15% α-chymotrypsin enzyme inhibition respectively with IC 50 values of greater than 500 μmol. The methanol extract showed 24.39±0.21% Urease enzyme inhibition with IC 50 values of greater than 400 μmol While dichloromethane extract has 11.46±0.09% enzyme inhibition with IC 50 values of greater than 500 μmol. The results clearly indicated that Heliotropium dasycarpum has cytotoxic potential and enzyme inhibition properties. Further study is needed to screen out antitumor and anti-ulcerative agents.

CYTOTOXIC, α-CHYMOTRYPSIN AND UREASE INHIBITION ACTIVITIES OF THE PLANT Heliotropium dasycarpum L.

PubMed Central

Ghaffari, Muhammad Abuzar; Chaudhary, Bashir Ahmed; Uzair, Muhammad; Ashfaq, Khuram

2016-01-01

Background: The aim of this study was to investigate Cytotoxic, α-Chymotrypsin and Urease inhibition activities of the plant Heliotropium dasycarpum. Materials & Methods: Dichloromethane and methanol extracts of the plant were evaluated for cytotoxic, α-Chymotrypsin and Urease inhibition by using in vivo Brine Shrimp lethality bioassay and in vitro enzymatic inhibition assays respectively. Results: The methanol extract of the plant exhibited significant cytotoxic activity. Out of 30 brine shrimp larvae, 2 (6%), 26 (86%) and 28 (93%) larvae were survived at concentration of 1000μg/ml, 100μg/ml and 10μg/ml respectively with LD50; 215.837. Similarly 21 (70%), 25 (83%), 29 (96%) larvae were survived of dichloromethane plant extract with LD50; 6170.64. The methanol and dichloromethane extract exhibited 10.50±0.18% and 41.51±0.15% α-chymotrypsin enzyme inhibition respectively with IC50 values of greater than 500 μmol. The methanol extract showed 24.39±0.21% Urease enzyme inhibition with IC50 values of greater than 400 μmol While dichloromethane extract has 11.46±0.09% enzyme inhibition with IC50 values of greater than 500 μmol Conclusion: The results clearly indicated that Heliotropium dasycarpum has cytotoxic potential and enzyme inhibition properties. Further study is needed to screen out antitumor and anti-ulcerative agents. PMID:28480379

Design, synthesis and biological evaluation of diaziridinyl quinone isoxazole hybrids.

PubMed

Swapnaja, K Jones M; Yennam, Satyanarayana; Chavali, Murthy; Poornachandra, Y; Kumar, C Ganesh; Muthusamy, Krubakaran; Jayaraman, Venkatesh Babu; Arumugam, Premkumar; Balasubramanian, Sridhar; Sriram, Kiran Kumar

2016-07-19

A series of novel diaziridinyl quinone isoxazole hybrids (9a-9j) were synthesized starting from 2, 5-dimethoxy acetophenone 1 via Claisen reaction, cyclisation, alkoxy carbonylation, hydrolysis, oxidation and aziridine insertion. All the compounds were screened for antimicrobial, anti-biofilm and cytotoxic activities. Among the screened compounds, the compound 9h showed good antibacterial and anti-biofilm activities with MIC value of 3.9, 3.9, 3.9 and 7.8 μg/mL, respectively, and IC50 values of 1.9, 2.5, 2.8 and 5.1 μM, respectively, against Staphylococcus aureus MTCC 96, S. aureus MLS-16 MTCC 2940, Bacillus subtilis MTCC 121 and Klebsiella planticola MTCC 530, and also exhibited potent antifungal activity against Candida albicans MTCC 227, C. albicans MTCC 854 and Candida krusei MTCC 3020 equipotent to standard miconazole (MIC value 7.8 μg/mL). All the synthesized compounds exhibited promising cytotoxicity against A549 and PC3 cell lines (IC50 values between 1 and 4 μM). Compounds 9b and 9j exhibited IC50 value of 0.5 μM which was similar to that of Mitomycin C against PC3 cell line. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Urease and serine protease inhibitory alkaloids from Isatis tinctoria.

PubMed

Ahmad, Ijaz; Fatima, Itrat; Afza, Nighat; Malik, Abdul; Lodhi, Muhammad Arif; Choudhary, Muhammad Iqbal

2008-12-01

Phytochemical investigations on the alkaloidal fraction of the whole plant of the Isatis tinctoria led to the isolation of the alkaloids 1-6., 3'-Hydroxyepiglucoisatisin (3), Epiglucoisatisin (2) were found to be potent urease inhibitors in a concentration-dependent manner with IC(50) values 25.63 +/- 0.74, 37.01 +/- 0.41 and 31.72 +/- 0.93, 47.33 +/- 0.31 microM against Bacillus pasteurii & Jack bean urease, respectively. Compounds 3 and 2 also showed potent inhibitory potential against alpha-chymotrypsin with IC(50) values of 23.40 +/- 0.21 and 27.45 +/- 0.23 microM, respectively.

In vitro anti-influenza viral activities of constituents from Caesalpinia sappan.

PubMed

Liu, Ai-Lin; Shu, Shi-Hui; Qin, Hai-Lin; Lee, Simon Ming Yuen; Wang, Yi-Tao; Du, Guan-Hua

2009-03-01

Six constituents with neuraminidase (NA) inhibitory activity, namely brazilein, brazilin, protosappanin A, 3-deoxysappanchalcone, sappanchalcone and rhamnetin, were isolated from the hearthwood of Caesalpinia sappan (Leguminosae). Their in vitro anti-influenza virus activities were evaluated with the cytopathic effect (CPE) reduction method. The results showed that 3-deoxysappanchalcone and sappanchalcone exhibited the highest activity against influenza virus (H3N2) with IC50 values of 1.06 and 2.06 microg/mL, respectively, in comparison to the positive control oseltamivir acid and ribavirin with IC50 values of 0.065 and 9.17 microg/mL, respectively.

Synthesis, kinetic studies and molecular modeling of novel tacrine dimers as cholinesterase inhibitors.

PubMed

de Aquino, Roney Anderson Nascimento; Modolo, Luzia Valentina; Alves, Rosemeire Brondi; de Fátima, Ângelo

2013-12-28

This study presents the synthesis of 15 new tacrine dimers as well as the Ki and IC50 results, studies of the kinetic mechanism, and molecular docking analysis of the dimers in relation to the cholinesterases hAChE, hBChE, EeAChE and eqBChE. In addition to spectroscopic characterization, X-ray structure determination was performed for two of the new compounds. These new dimers were found to be mixed nanomolar inhibitors of the evaluated targets with a broad and significant selectivity profile, and these properties are dependent on both the type of the linker and the volume of the hydroacridine alicyclic ring. The results indicate that the aromatic linkers play a significant role in generating specific interactions with the half-gorge region of the catalytic center. Thus, these types of linkers can positively modulate the electronic properties of the tacrine dimers studied with an improvement of their cholinesterase inhibition activity.

Combining galantamine and memantine in multitargeted, new chemical entities potentially useful in Alzheimer's disease.

PubMed

Simoni, Elena; Daniele, Simona; Bottegoni, Giovanni; Pizzirani, Daniela; Trincavelli, Maria L; Goldoni, Luca; Tarozzo, Glauco; Reggiani, Angelo; Martini, Claudia; Piomelli, Daniele; Melchiorre, Carlo; Rosini, Michela; Cavalli, Andrea

2012-11-26

Herein we report on a novel series of multitargeted compounds obtained by linking together galantamine and memantine. The compounds were designed by taking advantage of the crystal structures of acetylcholinesterase (AChE) in complex with galantamine derivatives. Sixteen novel derivatives were synthesized, using spacers of different lengths and chemical composition. The molecules were then tested as inhibitors of AChE and as binders of the N-methyl-d-aspartate (NMDA) receptor (NMDAR). Some of the new compounds were nanomolar inhibitors of AChE and showed micromolar affinities for NMDAR. All compounds were also tested for selectivity toward NMDAR containing the 2B subunit (NR2B). Some of the new derivatives showed a micromolar affinity for NR2B. Finally, selected compounds were tested using a cell-based assay to measure their neuroprotective activity. Three of them showed a remarkable neuroprotective profile, inhibiting the NMDA-induced neurotoxicity at subnanomolar concentrations (e.g., 5, named memagal, IC(50) = 0.28 nM).

Toward Highly Potent Cancer Agents by Modulating the C-2 Group of the Arylthioindole Class of Tubulin Polymerization Inhibitors

PubMed Central

La Regina, Giuseppe; Bai, Ruoli; Rensen, Whilelmina Maria; Di Cesare, Erica; Coluccia, Antonio; Piscitelli, Francesco; Famiglini, Valeria; Reggio, Alessia; Nalli, Marianna; Pelliccia, Sveva; Pozzo, Eleonora Da; Costa, Barbara; Granata, Ilaria; Porta, Amalia; Maresca, Bruno; Soriani, Alessandra; Iannitto, Maria Luisa; Santoni, Angela; Li, Junjie; Cona, Marlein Miranda; Chen, Feng; Ni, Yicheng; Brancale, Andrea; Dondio, Giulio; Vultaggio, Stefania; Varasi, Mario; Mercurio, Ciro; Martini, Claudia; Hamel, Ernest; Lavia, Patrizia; Novellino, Ettore; Silvestri, Romano

2013-01-01

New arylthioindole derivatives having different cyclic substituents at position 2 of the indole were synthesized as anticancer agents. Several compounds inhibited tubulin polymerization at submicromolar concentration and inhibited cell growth at low nanomolar concentrations. Compounds 18 and 57 were superior to the previously synthesized 5. Compound 18 was exceptionally potent as an inhibitor of cell growth: it showed IC50 = 1.0 nM in MCF-7 cells, and it was uniformly active in the whole panel of cancer cells and superior to colchicine and combretastatin A-4. Compounds 18, 20, 55, and 57 were notably more potent than vinorelbine, vinblastine, and paclitaxel in the NCI/ADR-RES and Messa/Dx5 cell lines, which overexpress P-glycoprotein. Compounds 18 and 57 showed initial vascular disrupting effects in a tumor model of liver rhabdomyosarcomas at 15 mg/kg intravenous dosage. Derivative 18 showed water solubility and higher metabolic stability than 5 in human liver microsomes. PMID:23214452

N- and C-terminal substance P fragments: differential effects on striatal [3H]substance P binding and NK1 receptor internalization.

PubMed

Michael-Titus, A T; Blackburn, D; Connolly, Y; Priestley, J V; Whelpton, R

1999-07-13

N- and C-terminal substance P (SP) fragments increase striatal dopamine outflow at nanomolar concentrations. This contrasts with their low affinity for NK1 receptors. To explore this discrepancy, we investigated the interaction of SP and SP fragments with NK1 sites in fresh striatal slices, the same model used in the functional studies on dopamine outflow. [3H]SP bound specifically to one site (Kd = 6.6 +/- 0.9 nM; Bmax = 12.6 +/- 0.7 fmol/mg protein). [3H]SP binding was displaced by SP (IC50 = 11.8 nM), but not by SP(1-7) or SP(5-11), up to 10 microM. In contrast, 10 nM SP(1-7) or SP(5-11) induced significant internalization of the NK1 receptor, similar to that induced by SP. We suggest that SP fragments have high affinity for an NK1 receptor conformer which is different from that labelled by [3H]SP.

Antimalarial benzoheterocyclic 4-aminoquinolines: Structure-activity relationship, in vivo evaluation, mechanistic and bioactivation studies.

PubMed

Ongarora, Dennis S B; Strydom, Natasha; Wicht, Kathryn; Njoroge, Mathew; Wiesner, Lubbe; Egan, Timothy J; Wittlin, Sergio; Jurva, Ulrik; Masimirembwa, Collen M; Chibale, Kelly

2015-09-01

A novel class of benzoheterocyclic analogues of amodiaquine designed to avoid toxic reactive metabolite formation was synthesized and evaluated for antiplasmodial activity against K1 (multidrug resistant) and NF54 (sensitive) strains of the malaria parasite Plasmodium falciparum. Structure-activity relationship studies led to the identification of highly promising analogues, the most potent of which had IC50s in the nanomolar range against both strains. The compounds further demonstrated good in vitro microsomal metabolic stability while those subjected to in vivo pharmacokinetic studies had desirable pharmacokinetic profiles. In vivo antimalarial efficacy in Plasmodium berghei infected mice was evaluated for four compounds, all of which showed good activity following oral administration. In particular, compound 19 completely cured treated mice at a low multiple dose of 4×10mg/kg. Mechanistic and bioactivation studies suggest hemozoin formation inhibition and a low likelihood of forming quinone-imine reactive metabolites, respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

DUPA conjugation of a cytotoxic indenoisoquinoline topoisomerase I inhibitor for selective prostate cancer cell targeting.

PubMed

Roy, Jyoti; Nguyen, Trung Xuan; Kanduluru, Ananda Kumar; Venkatesh, Chelvam; Lv, Wei; Reddy, P V Narasimha; Low, Philip S; Cushman, Mark

2015-04-09

Prostate-specific membrane antigen (PSMA) is overexpressed in most prostate cancer cells while being present at low or undetectable levels in normal cells. This difference provides an opportunity to selectively deliver cytotoxic drugs to prostate cancer cells while sparing normal cells that lack PSMA, thus improving potencies and reducing toxicities. PSMA has high affinity for 2-[3-(1,3-dicarboxypropyl)ureido]pentanedioic acid (DUPA) (Ki = 8 nM). After binding to a DUPA-drug conjugate, PSMA internalizes, unloads the conjugate, and returns to the surface. In the present studies, an indenoisoquinoline topoisomerase I inhibitor was conjugated to DUPA via a peptide linker and a drug-release segment that facilitates intracellular cleavage to liberate the drug cargo. The DUPA-indenoisoquinoline conjugate exhibited an IC50 in the low nanomolar range in 22RV1 cell cultures and induced a complete cessation of tumor growth with no toxicity, as determined by loss of body weight and death of treated mice.

Phytochemical investigations and antioxidant potential of roots of Leea macrophylla (Roxb.).

PubMed

Mahmud, Zobaer Al; Bachar, Sitesh C; Hasan, Choudhury Mahmood; Emran, Talha Bin; Qais, Nazmul; Uddin, Mir Muhammad Nasir

2017-07-06

Oleanolic acid (NZ-15), 7 α, 28-olean diol (NZ-38) and Stigmasterol (NZ-14) were isolated from the ethanolic extracts of the roots of Leea macrophylla (Family: Leeaceae) by using chromatographic analysis. This is the first report of isolation of these compounds from this plant. Their structures were constructed by spectroscopic analysis and by comparing the data with the published one. Subsequently the ethanolic extract was fractionated with two organic solvents and all the fractions were studied to evaluate their in vitro antioxidant property. The ethanolic extract was fractionated with two organic solvents and all the fractions were studied to evaluate their in vitro antioxidant property by DPPH free radical scavenging assay, superoxide anion radical scavenging assay, nitric oxide radical scavenging assay, and reducing power assay. In the DPPH free radical scavenging assay and superoxide radical scavenging assay, the ethyl acetate soluble fraction of ethanolic extract revealed the highest free radical scavenging activity with IC 50 value of 2.65 and 155.62 μg/ml, respectively as compared to standard ascorbic acid (IC 50 value of 5.8 and 99.66 μg/ml). Ethyl acetate fraction also possessed highest reducing power activity with an EC50 value of 15.27 μg/ml compared to ascorbic acid (EC 50 0.91 μg/ml). On the other hand, the carbon tetrachloride fraction exhibited most significant NO scavenging activity with IC 50 value of 277.8 μg/ml that was even higher than that of standard ascorbic acid (IC 50 value 356.04 μg/ml). In addition, the total phenolic contents of these extract and fractions were evaluated using Folin-Ciocalteu reagent and varied from 7.93 to 50.21 mg/g dry weight expressed as gallic acid equivalents (GAE). This study showed that different extracts of roots of L. macrophylla possess potential DPPH, superoxide, and NO free radical scavenging activities. The antioxidant activities of the plant extracts might be due to the presence of oleanolic acid, oleanolic acid derivative 7 α, 28-olean diol and stigmasterol.

A facile stereoselective synthesis of dispiro-indeno pyrrolidine/pyrrolothiazole-thiochroman hybrids and evaluation of their antimycobacterial, anticancer and AchE inhibitory activities.

PubMed

Bharkavi, Chelliah; Vivek Kumar, Sundaravel; Ashraf Ali, Mohamed; Osman, Hasnah; Muthusubramanian, Shanmugam; Perumal, Subbu

2016-11-15

A facile stereoselective synthesis of novel dispiro indeno pyrrolidine/pyrrolothiazole-thiochroman hybrids has been achieved by 1,3-dipolar cycloaddition of azomethine ylides, generated in situ from ninhydrin and sarcosine/thiaproline, on a series of 3-benzylidenethiochroman-4-ones. The synthesised compounds were screened for their antimycobacterial, anticancer and AchE inhibition activities. Compound 4l (IC 50 1.07μM) has been found to exhibit the most potent antimycobacterial activity compared to cycloserine (12 times), pyrimethamine (37 times) and ethambutol (IC 50 <1.56μM) and 6l (IC 50 =2.87μM) is more active than both cycloserine (4 times) and pyrimethamine (12 times). Three compounds, 4a, 6b and 6i, display good anticancer activity against CCRF-CEM cell lines. Compounds 6g and 4g display maximum AchE inhibitory activity with IC 50 values of 1.10 and 1.16μmol/L respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.

New isopimarane diterpenes and nortriterpene with cytotoxic activity from Ephorbia alatavica Boiss.

PubMed

Rozimamat, Rushangul; Hu, Rui; Aisa, Haji Akber

2018-06-01

Three new isopimarane diterpenes and one new nor-triterpenes, along with five known diterpenes were isolated from the whole areal part of Ephorbia alatavica Boiss. The structures of the new compounds (1-4) were determined based on extensive spectroscopic analysis, including HR-ESIMS, 1D and 2D NMR data. A plausible biosynthetic pathway for new compounds (1-4) were hypothesized. All isolated compounds were screen for cytotoxicity activity against MCF-8, HeLa and A549 cell lines in vitro by MTT assay. New compound 1 and known 9 showed potential cytotoxic activities with IC 50 values of 15.327 μg/mL, 23.066 μg/mL against MCF-8 cell lines, compound1 showed noteworthy cytotoxic activity with IC 50 13.033 μg/mL against A549 cancer cell line. New compounds 2, 4 and 4 showed moderate cytotoxic activities three human cancer lines with IC 50 value around 50 μg/mL, which compared with positive control doxorubicin (DOX). Copyright © 2018 Elsevier B.V. All rights reserved.

Synthesis, Characterization, and Anti-Cancer Activity of Some New N'-(2-Oxoindolin-3-ylidene)-2-propylpentane hydrazide-hydrazones Derivatives.

PubMed

El-Faham, Ayman; Farooq, Muhammad; Khattab, Sherine N; Abutaha, Nael; Wadaan, Mohammad A; Ghabbour, Hazem A; Fun, Hoong-Kun

2015-08-13

Eight novel N'-(2-oxoindolin-3-ylidene)-2-propylpentane hydrazide-hydrazone derivatives 4a-h were synthesized and fully characterized by IR, NMR ((1)H-NMR and (13)C-NMR), elemental analysis, and X-ray crystallography. The cyto-toxicity and in vitro anti-cancer evaluation of the prepared compounds have been assessed against two different human tumour cell lines including human liver (HepG2) and leukaemia (Jurkat), as well as in normal cell lines derived from human embryonic kidney (HEK293) using MTT assay. The compounds 3e, 3f, 4a, 4c, and 4e revealed promising anti-cancer activities in tested human tumour cells lines (IC50 values between 3 and 7 μM) as compared to the known anti-cancer drug 5-Fluorouracil (IC50 32-50 μM). Among the tested compounds, 4a showed specificity against leukaemia (Jurkat) cells, with an IC50 value of 3.14 μM, but this compound was inactive in liver cancer and normal cell lines.

Synthesis and discovery of novel piperidone-grafted mono- and bis-spirooxindole-hexahydropyrrolizines as potent cholinesterase inhibitors.

PubMed

Kia, Yalda; Osman, Hasnah; Kumar, Raju Suresh; Murugaiyah, Vikneswaran; Basiri, Alireza; Perumal, Subbu; Wahab, Habibah A; Bing, Choi Sy

2013-04-01

Three-component reaction of a series of 1-acryloyl-3,5-bisbenzylidenepiperidin-4-ones with isatin and L-proline in 1:1:1 and 1:2:2 molar ratios in methanol afforded, respectively the piperidone-grafted novel mono- and bisspiro heterocyclic hybrids comprising functionalized piperidine, pyrrolizine and oxindole ring systems in good yields. The in vitro evaluation of cholinesterase enzymes inhibitory activity of these cycloadducts disclosed that monospiripyrrolizines (8a-k), are more active with IC50 ranging from 3.36 to 20.07 μM than either the dipolarophiles (5a-k) or bisspiropyrrolizines (9a-k). The compounds, 8i and 8e with IC50 values of 3.36 and 3.50 μM, respectively showed the maximum inhibition of acethylcholinesterase (AChE) and butrylylcholinestrase (BuChE). Molecular modeling simulation, disclosed the binding interactions of the most active compounds to the active site residues of their respective enzymes. The docking results were in accordance with the IC50 values obtained from in vitro cholinesterase assay. Copyright © 2013 Elsevier Ltd. All rights reserved.

In vitro susceptibility of Trypanosoma brucei brucei to selected essential oils and their major components.

PubMed

Costa, Sonya; Cavadas, Cláudia; Cavaleiro, Carlos; Salgueiro, Lígia; do Céu Sousa, Maria

2018-07-01

Aiming for discovering effective and harmless antitrypanosomal agents, 17 essential oils and nine major components were screened for their effects on T. b. brucei. The essential oils were obtained by hydrodistillation from fresh plant material and analyzed by GC and GC-MS. The trypanocidal activity was assessed using blood stream trypomastigotes cultures of T. b. brucei and the colorimetric resazurin method. The MTT test was used to assess the cytotoxicity of essential oils on macrophage cells and Selectivity Indexes were calculated. Of the 17 essential oils screened three showed high trypanocidal activity (IC 50  < 10 μg/mL): Juniperus oxycedrus (IC 50 of 0.9 μg/mL), Cymbopogon citratus (IC 50 of 3.2 μg/mL) and Lavandula luisieri (IC 50 of 5.7 μg/mL). These oils had no cytotoxic effects on macrophage cells showing the highest values of Selectivity Index (63.4, 9.0 and 11.8, respectively). The oils of Distichoselinum tenuifolium, Lavandula viridis, Origanum virens, Seseli tortuosom, Syzygium aromaticum, and Thymbra capitata also exhibited activity (IC 50 of 10-25 μg/mL) but showed cytotoxicity on macrophages. Of the nine compounds tested, α-pinene (IC 50 of 2.9 μg/mL) and citral (IC 50 of 18.9 μg/mL) exhibited the highest anti-trypanosomal activities. Citral is likely the active component of C. citratus and α-pinene is responsible for the antitrypanosomal effects of J. oxycedrus. The present work leads us to propose the J. oxycedrus, C. citratus and L. luisieri oils as valuable sources of new molecules for African Sleeping Sickness treatment. Copyright © 2018 Elsevier Inc. All rights reserved.

Comparing Various In Vitro Prediction Criteria to Assess the Potential of a New Molecular Entity to Inhibit Organic Anion Transporting Polypeptide 1B1.

PubMed

Vaidyanathan, Jayabharathi; Yoshida, Kenta; Arya, Vikram; Zhang, Lei

2016-07-01

Evaluation of organic anion transporting polypeptide (OATP) 1B1-mediated drug-drug interactions (DDIs) is an integral part of drug development and is recommended by regulatory agencies. In this study we compared various prediction methods and cutoff criteria based on in vitro inhibition data to assess the potential of a new molecular entity to inhibit OATP1B1 in vivo. In vitro (eg, IC50 , fu,p ) and in vivo (eg, dose, Cmax , change in area under the curve [AUC]) data for 11 substrates and 61 inhibitors for OATP1B1 were obtained from literature and Drugs@FDA, which include 107 clinical (in vivo) DDI studies. Substrate dependency and variability of IC50 values were noted. In addition to the ratio of unbound or total systemic concentration (Imax,u and Imax ) to IC50 , maximum unbound inhibitor concentration at the inlet to the liver (Iu,in,max ) was used for the estimation of "R value" where R = 1 + Iu,in,max /IC50 . Based on our analyses, Imax /Ki ≥ 0.1, R ≥ 1.04, or R ≥ 1.1 seem to be appropriate for reducing the false-negative (FN) predictions. However, as compared with R ≥ 1.1, Imax /Ki ≥ 0.1 and R ≥ 1.04 resulted in higher false positives (FPs) and lower true negatives (TNs). R ≥ 1.1, Imax,u /Ki ≥ 0.02, and R ≥ 1.25 alone, or combined criterion of Imax /Ki ≥ 0.1 and R ≥ 1.25, were reasonable to determine the need to perform clinical DDI studies with OATP1B1 substrates with similar positive and negative predictive values. Possible reasons of FP or FN from different decision criteria should be considered when interpreting prediction results, and the variability in IC50 determination needs to be understood and minimized. © 2016, The American College of Clinical Pharmacology.

Effects of pyrogallol, hydroquinone and duroquinone on responses to nitrergic nerve stimulation and NO in the rat anococcygeus muscle

PubMed Central

La, Mylinh; Rand, Michael J

1999-01-01

The hypothesis that endogenous superoxide dismutase (SOD) protects the nitrergic transmitter from inactivation by superoxide and that this explains the lack of sensitivity of the transmitter to superoxide generators was tested in the rat isolated anococcygeus muscle.Responses to nitrergic nerve stimulation or to NO were not significantly affected by exogenous SOD or by the Cu/Zn SOD inhibitor diethyldithiocarbamic acid (DETCA).Hydroquinone produced a concentration-dependent reduction of responses to NO with an IC50 of 27 μM, and higher concentrations reduced relaxant responses to nitrergic nerve stimulation with an IC50 of 612 μM. The effects of hydroquinone were only slightly reversed by SOD, so it does not appear to be acting as a superoxide generator.Pyrogallol produced a concentration-dependent reduction in responses to NO with an IC50 value of 39 μM and this effect was reversed by SOD (100–1000 u ml−1). Pyrogallol did not affect responses to nitrergic nerve stimulation. Treatment with DETCA did not alter the differentiating action of pyrogallol.Duroquinone produced a concentration-dependent reduction of relaxations to NO with an IC50 value of 240 μM and 100 μM slightly decreased nitrergic relaxations. After treatment with DETCA, duroquinone produced greater reductions of relaxant responses to NO and to nitrergic stimulation, the IC50 values being 8.5 μM for NO and 40 μM for nitrergic nerve stimulation: these reductions were reversed by SOD.The findings do not support the hypothesis that the presence of Cu/Zn SOD explains the greater susceptibility of NO than the nitrergic transmitter to the superoxide generator pyrogallol, but suggest that it may play a role in the effects of duroquinone. PMID:10051154

The relationship between antiglycation activity and procyanidin and phenolic content in commercial grape seed products.

PubMed

Sun, Cathy; McIntyre, Kristina; Saleem, Ammar; Haddad, Pierre Selim; Arnason, John Thor

2012-02-01

Eight commercial grape seed products (GSPs) were assessed for their inhibition of the formation of advanced glycation end-products in vitro. All 8 commercial GSPs included in this study were potent inhibitors of advanced glycation end-product formation with IC(50) values ranging from 2.93 to 20.0 µg/mL. Total procyanidin content ranged from 60% to 73%. HPLC-DAD-ELSD results indicate that (+)-catechin, (-)-epicatechin, procyanidin B1, and procyanidin B2 were predominant and ubiquitously present in all the products under study, while gallic acid and procyanidin B4 were present in relatively minor amounts. The IC(50) values correlated with total phenolic content, and multiple regression analysis indicated that IC(50) is a linear function of the concentration of gallic acid and procyanidins B1, B2, and B4. Based on this study, GSPs have the potential to complement conventional diabetes medication toward disease management and prevention.

Structure-based design, synthesis and biological evaluation of β-glucuronidase inhibitors

NASA Astrophysics Data System (ADS)

Khan, Khalid M.; Ambreen, Nida; Taha, Muhammad; Halim, Sobia A.; Zaheer-ul-Haq; Naureen, Shagufta; Rasheed, Saima; Perveen, Shahnaz; Ali, Sajjad; Choudhary, Mohammad Iqbal

2014-05-01

Using structure-based virtual screening approach, a coumarin derivative ( 1) was identified as β-glucuronidase inhibitor. A focused library of coumarin derivatives was synthesized by eco-benign version of chemical reaction, and all synthetic compounds were characterized by using spectroscopy. These compounds were found to be inhibitor of β-glucuronidase with IC50 values in a micromolar range. All synthetic compounds exhibited interesting inhibitory activity against β-glucuronidase, however, their potency varied substantially from IC50 = 9.9-352.6 µM. Of twenty-one compounds, four exhibited a better inhibitory profile than the initial hit 1. Interestingly, compounds 1e, 1k, 1n and 1p exhibited more potency than the standard inhibitor with IC50 values 34.2, 21.4, 11.7, and 9.9 µM, respectively. We further studied their dose responses and also checked our results by using detergent Triton ×-100. We found that our results are true and not affected by detergent.

Structure-based design, synthesis and biological evaluation of β-glucuronidase inhibitors.

PubMed

Khan, Khalid M; Ambreen, Nida; Taha, Muhammad; Halim, Sobia A; Zaheer-ul-Haq; Naureen, Shagufta; Rasheed, Saima; Perveen, Shahnaz; Ali, Sajjad; Choudhary, Mohammad Iqbal

2014-05-01

Using structure-based virtual screening approach, a coumarin derivative (1) was identified as β-glucuronidase inhibitor. A focused library of coumarin derivatives was synthesized by eco-benign version of chemical reaction, and all synthetic compounds were characterized by using spectroscopy. These compounds were found to be inhibitor of β-glucuronidase with IC50 values in a micromolar range. All synthetic compounds exhibited interesting inhibitory activity against β-glucuronidase, however, their potency varied substantially from IC50 = 9.9-352.6 µM. Of twenty-one compounds, four exhibited a better inhibitory profile than the initial hit 1. Interestingly, compounds 1e, 1k, 1n and 1p exhibited more potency than the standard inhibitor with IC50 values 34.2, 21.4, 11.7, and 9.9 µM, respectively. We further studied their dose responses and also checked our results by using detergent Triton ×-100. We found that our results are true and not affected by detergent.

Isatin based Schiff bases as inhibitors of α-glucosidase: Synthesis, characterization, in vitro evaluation and molecular docking studies.

PubMed

Rahim, Fazal; Malik, Fazal; Ullah, Hayat; Wadood, Abdul; Khan, Fahad; Javid, Muhammad Tariq; Taha, Muhammad; Rehman, Wajid; Ur Rehman, Ashfaq; Khan, Khalid Mohammed

2015-06-01

Isatin base Schiff bases (1-20) were synthesized, characterized by (1)H NMR and EI/MS and evaluated for α-glucosidase inhibitory potential. Out of these twenty (20) compounds only six analogs showed potent α-glucosidase inhibitory potential with IC50 value ranging in between 2.2±0.25 and 83.5±1.0μM when compared with the standard acarbose (IC50=840±1.73μM). Among the series compound 2 having IC50 value (18.3±0.56μM), 9 (83.5±1.0μM), 11 (3.3±0.25μM), 12 (2.2±0.25μM), 14 (11.8±0.15μM), and 20 (3.0±0.15μM) showed excellent inhibitory potential many fold better than the standard acarbose. The binding interactions of these active analogs were confirmed through molecular docking. Copyright © 2015 Elsevier Inc. All rights reserved.

Design, Synthesis, and Evaluation of Novel Ferroquine and Phenylequine Analogues as Potential Antiplasmodial Agents.

PubMed

Jacobs, Leon; de Kock, Carmen; de Villiers, Katherine A; Smith, Peter J; Smith, Vincent J; van Otterlo, Willem A L; Blackie, Margaret A L

2015-12-01

7-Chloroquinoline-based antimalarial drugs are effective in the inhibition of hemozoin formation in the food vacuole of the Plasmodium parasite, the causative agent of malaria. We synthesized five series of ferroquine (FQ) and phenylequine (PQ) derivatives, which display good in vitro efficacy toward both the chloroquine-sensitive (CQS) NF54 (IC50 : 4.2 nm) and chloroquine-resistant (CQR) Dd2 (IC50 : 33.7 nm) strains of P. falciparum. Several compounds were found to have good inhibitory activity against β-hematin formation in an NP-40 detergent assay, with IC50 values ranging between 10.4 and 19.2 μm. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mutagenic and Cytotoxicity LQB 123 Profile: Safety and Tripanocidal Effect of a Phenyl-t-Butylnitrone Derivative

PubMed Central

Cupello, Mauricio Peixoto; Saraiva, Francis Monique; Ippolito, Pedro; Fernandes, Andréia da Silva; Costa, Debora de Sousa dos Santos; Paula, Jessica Isis Oliveira; Costa, Paulo Roberto Ribeiro; Dias, Ayres Guimarães

2017-01-01

The therapeutic options for Chagas disease are limited and its treatment presents a number of drawbacks including toxicity, drug resistance, and insufficient effectiveness against the chronic stage of the disease. Therefore, new therapeutical options are mandatory. In the present work, we evaluated the effect of a phenyl-tert-butylnitrone (PBN) derivate, LQB 123, against Trypanosoma cruzi forms. LQB 123 presented a trypanocidal effect against bloodstream trypomastigotes (IC50 = 259.4 ± 6.1 μM) and intracellular amastigotes infecting peritoneal macrophages (IC50 = 188.2 ± 47.5 μM), with no harmful effects upon the mammalian cells (CC50 values greater than 4 mM), resulting in a high selectivity index (CC50/IC50 > 20). Additionally, metacyclic trypomastigotes submitted to LQB 123 presented an IC50 of about 191.8 ± 10.5 μM and epimastigotes forms incubated with different concentrations of LQB 123 presented an inhibition of parasite growth with an IC50 of 255.1 ± 3.6 μM. Finally, we investigated the mutagenic potential of the nitrone by the Salmonella/microsome assay and observed no induction of mutagenicity even in concentrations as high as 33000 μM. Taken together, these results present a nonmutagenic compound, with trypanocidal activity against all relevant forms of T. cruzi, offering new insights into CD treatment suggesting additional in vivo tests. PMID:28316976

Mutagenic and Cytotoxicity LQB 123 Profile: Safety and Tripanocidal Effect of a Phenyl-t-Butylnitrone Derivative.

PubMed

Cupello, Mauricio Peixoto; Saraiva, Francis Monique; Ippolito, Pedro; Fernandes, Andréia da Silva; Menna-Barreto, Rubem Figueiredo Sadoko; Costa, Debora de Sousa Dos Santos; Paula, Jessica Isis Oliveira; Costa, Paulo Roberto Ribeiro; Nogueira, Natália Pereira; Felzenswalb, Israel; Dias, Ayres Guimarães; Paes, Marcia Cristina

2017-01-01

The therapeutic options for Chagas disease are limited and its treatment presents a number of drawbacks including toxicity, drug resistance, and insufficient effectiveness against the chronic stage of the disease. Therefore, new therapeutical options are mandatory. In the present work, we evaluated the effect of a phenyl- tert -butylnitrone (PBN) derivate, LQB 123, against Trypanosoma cruzi forms. LQB 123 presented a trypanocidal effect against bloodstream trypomastigotes (IC 50 = 259.4 ± 6.1  μ M) and intracellular amastigotes infecting peritoneal macrophages (IC 50 = 188.2 ± 47.5  μ M), with no harmful effects upon the mammalian cells (CC 50 values greater than 4 mM), resulting in a high selectivity index (CC 50 /IC 50 > 20). Additionally, metacyclic trypomastigotes submitted to LQB 123 presented an IC 50 of about 191.8 ± 10.5  μ M and epimastigotes forms incubated with different concentrations of LQB 123 presented an inhibition of parasite growth with an IC 50 of 255.1 ± 3.6  μ M. Finally, we investigated the mutagenic potential of the nitrone by the Salmonella /microsome assay and observed no induction of mutagenicity even in concentrations as high as 33000  μ M. Taken together, these results present a nonmutagenic compound, with trypanocidal activity against all relevant forms of T. cruzi , offering new insights into CD treatment suggesting additional in vivo tests.

New hydrazine and hydrazide quinoxaline 1,4-di-N-oxide derivatives: In silico ADMET, antiplasmodial and antileishmanial activity.

PubMed

Quiliano, Miguel; Pabón, Adriana; Ramirez-Calderon, Gustavo; Barea, Carlos; Deharo, Eric; Galiano, Silvia; Aldana, Ignacio

2017-04-15

We report the design (in silico ADMET criteria), synthesis, cytotoxicity studies (HepG-2 cells), and biological evaluation of 15 hydrazine/hydrazide quinoxaline 1,4-di-N-oxide derivatives against the 3D7 chloroquine sensitive strain and FCR-3 multidrug resistant strain of Plasmodium falciparum and Leishmania infantum (axenic amastigotes). Fourteen of derivatives are novel quinoxaline 1,4-di-N-oxide derivatives. Compounds 18 (3D7 IC 50 =1.40μM, FCR-3 IC 50 =2.56μM) and 19 (3D7 IC 50 =0.24μM, FCR-3 IC 50 =2.8μM) were identified as the most active against P. falciparum, and they were the least cytotoxic (CC 50 -values>241μM) and most selective (SI>86). None of the compounds tested against L. infantum were considered to be active. Additionally, the functional role of the hydrazine and hydrazide structures were studied in the quinoxaline 1,4-di-N-oxide system. Copyright © 2017 Elsevier Ltd. All rights reserved.

Broad spectrum anti-infective properties of benzisothiazolones and the parallels in their anti-bacterial and anti-fungal effects.

PubMed

Gopinath, P; Yadav, R K; Shukla, P K; Srivastava, K; Puri, S K; Muraleedharan, K M

2017-03-01

Various mono- and bis-benzisothiazolone derivatives were synthesized and screened against different strains of bacteria and fungi in order to understand the effect of multiple electrophilic sulfur atoms and substitution pattern in the immediate vicinity of reactive sulfur. Staphyllococcus aureus-ATCC 7000699, MRSA and S. aureus-ATCC 29213 (Quality Control strain) were more susceptible to this class of compounds, and the most potent derivative 1.15 had MIC 50 of 0.4μg/mL (cf. Gentamicin=0.78μg/mL). CLogP value, optimally in the range of 2.5-3.5, appeared to contribute more to the activity than the steric and electronic effects of groups attached at nitrogen. By and large, their anti-fungal activities also followed a similar trend with respect to the structure and CLogP values. The best potency of IC 50 =0.1μg/mL was shown by N-benzyl derivative (1.7) against Aspergillus fumigatus; it was also potent against Candida albicans, Cryptococcus neoformans, Sporothrix schenckii, and Candida parapsilosis with IC 50 values ranging from 0.4 to 1.3μg/mL. Preliminary studies also showed that this class of compounds have the ability to target malaria parasite with IC 50 values in low micromolar range, and improvement of selectivity is possible through structure optimization. Copyright © 2017 Elsevier Ltd. All rights reserved.

In vitro effect of important herbal active constituents on human cytochrome P450 1A2 (CYP1A2) activity.

PubMed

Pan, Yan; Tiong, Kai Hung; Abd-Rashid, Badrul Amini; Ismail, Zakiah; Ismail, Rusli; Mak, Joon Wah; Ong, Chin Eng

2014-10-15

This study was designed to investigate eight herbal active constituents (andrographolide, asiaticoside, asiatic acid, madecassic acid, eupatorin, sinensetin, caffeic acid, and rosmarinic acid) on their potential inhibitory effects on human cytochrome P450 1A2 (CYP1A2) activity. A fluorescence-based enzyme assay was performed by co-incubating human cDNA-expressed CYP1A2 with its selective probe substrate, 3-cyano-7-ethoxycoumarin (CEC), in the absence or presence of various concentrations of herbal active constituents. The metabolite (cyano-hydroxycoumarin) formed was subsequently measured in order to obtain IC50 values. The results indicated that only eupatorin and sinensetin moderately inhibited CYP1A2 with IC50 values of 50.8 and 40.2 μM, while the other active compounds did not significantly affect CYP1A2 activity with IC50 values more than 100 μM. Ki values further determined for eupatorin and sinensetin were 46.4 and 35.2 μM, respectively. Our data indicated that most of the investigated herbal constituents have negligible CYP1A2 inhibitory effect. In vivo studies however may be warranted to ascertain the inhibitory effect of eupatorin and sinensetin on CYP1A2 activity in clinical situations. Copyright © 2014 Elsevier GmbH. All rights reserved.

Effects of Fungicides on Rat's Neurosteroid Synthetic Enzymes

PubMed Central

Shen, Xiuwei; Chen, Fan; Chen, Lanlan; Su, Ying; Huang, Ping

2017-01-01

Exposure to environmental endocrine disruptors may interfere with nervous system's activity. Fungicides such as tebuconazole, triadimefon, and vinclozolin have antifungal activities and are used to prevent fungal infections in agricultural plants. In the present study, we studied effects of tebuconazole, triadimefon, and vinclozolin on rat's neurosteroidogenic 5α-reductase 1 (5α-Red1), 3α-hydroxysteroid dehydrogenase (3α-HSD), and retinol dehydrogenase 2 (RDH2). Rat's 5α-Red1, 3α-HSD, and RDH2 were cloned and expressed in COS-1 cells, and effects of these fungicides on them were measured. Tebuconazole and triadimefon competitively inhibited 5α-Red1, with IC50 values of 8.670 ± 0.771 × 10−6 M and 17.390 ± 0.079 × 10−6 M, respectively, while vinclozolin did not inhibit the enzyme at 100 × 10−6 M. Triadimefon competitively inhibited 3α-HSD, with IC50 value of 26.493 ± 0.076 × 10−6 M. Tebuconazole and vinclozolin weakly inhibited 3α-HSD, with IC50 values about 100 × 10−6 M, while vinclozolin did not inhibit the enzyme even at 100 × 10−6 M. Tebuconazole and triadimefon weakly inhibited RDH2 with IC50 values over 100 × 10−6 M and vinclozolin did not inhibit this enzyme at 100 × 10−6 M. Docking study showed that tebuconazole, triadimefon, and vinclozolin bound to the steroid-binding pocket of 3α-HSD. In conclusion, triadimefon potently inhibited rat's neurosteroidogenic enzymes, 5α-Red1 and 3α-HSD. PMID:28812018

In vitro monoamine oxidase inhibition potential of alpha-methyltryptamine analog new psychoactive substances for assessing possible toxic risks.

PubMed

Wagmann, Lea; Brandt, Simon D; Kavanagh, Pierce V; Maurer, Hans H; Meyer, Markus R

2017-04-15

Tryptamines have emerged as new psychoactive substances (NPS), which are distributed and consumed recreationally without preclinical studies or safety tests. Within the alpha-methylated tryptamines, some of the psychoactive effects of the prototypical alpha-methyltryptamine (AMT) have been described decades ago and a contributing factor of its acute toxicity appears to involve the inhibition of monoamine oxidase (MAO). However, detailed information about analogs is scarce. Therefore, thirteen AMT analogs were investigated for their potential to inhibit MAO. An in vitro assay analyzed using hydrophilic interaction liquid chromatography-high resolution-tandem mass spectrometry was developed and validated. The AMT analogs were incubated with recombinant human MAO-A or B and kynuramine, a non-selective MAO substrate to determine the IC 50 values. The known MAO-A inhibitors 5-(2-aminopropyl)indole (5-IT), harmine, harmaline, yohimbine, and the MAO-B inhibitor selegiline were tested for comparison. AMT and all analogs showed MAO-A inhibition properties with IC 50 values between 0.049 and 166μM, whereas four analogs inhibited also MAO-B with IC 50 values between 82 and 376μM. 7-Me-AMT provided the lowest IC 50 value against MAO-A comparable to harmine and harmaline and was identified as a competitive MAO-A inhibitor. Furthermore, AMT, 7-Me-AMT, and nine further analogs inhibited MAO activity in human hepatic S9 fraction used as model for the human liver which expresses both isoforms. The obtained results suggested that MAO inhibition induced by alpha-methylated tryptamines might be clinically relevant concerning possible serotonergic and adrenergic effects and interactions with drugs (of abuse) particularly acting as monoamine reuptake inhibitors. However, as in vitro assays have only limited conclusiveness, further studies are needed. Copyright © 2017 Elsevier B.V. All rights reserved.

Study of cytotoxic activity, podophyllotoxin, and deoxypodophyllotoxin content in selected Juniperus species cultivated in Poland.

PubMed

Och, Marek; Och, Anna; Cieśla, Łukasz; Kubrak, Tomasz; Pecio, Łukasz; Stochmal, Anna; Kocki, Janusz; Bogucka-Kocka, Anna

2015-06-01

The demand for podophyllotoxin and deoxypodophyllotoxin is still increasing and commercially exploitable sources are few and one of them, Podophyllum hexandrum Royle (Berberidaceae), is a "critically endangered" species. The first aim was to quantify the amount of podophyllotoxin and deoxypodophyllotoxin in 61 Juniperus (Cupressaceae) samples. Cytotoxic activity of podophyllotoxin and ethanolic leaf extracts of Juniperus scopulorum Sarg. "Blue Pacific" and Juniperus communis L. "Depressa Aurea" was examined against different leukemia cell lines. Ultra-performance liquid chromatography (UPLC) analysis was performed with the use of a Waters ACQUITY UPLC(TM) system (Waters Corp., Milford, MA). The peaks of podophyllotoxin and deoxypodophyllotoxin were assigned on the basis of their retention data and mass-to-charge ratio (m/z). Trypan blue assay was performed to obtain IC50 cytotoxicity values against selected leukemia cell lines. Juniperus scopulorum was characterized with the highest level of podophyllotoxin (486.7 mg/100 g DW) while Juniperus davurica Pall. contained the highest amount of deoxypodophyllotoxin (726.8 mg/100 g DW). Podophyllotoxin IC50 cytotoxicity values against J45.01 and CEM/C1 leukemia cell lines were 0.0040 and 0.0286 µg/mL, respectively. Juniperus scopulorum extract examined against J45.01 and HL-60/MX2 leukemia cell lines gave the respective IC50 values: 0.369-9.225 µg/mL. Juniperus communis extract was characterized with the following IC50 cytotoxity values against J45.01 and U-266B1 cell lines: 3.310-24.825 µg/mL. Juniperus sp. can be considered as an alternative source of podophyllotoxin and deoxypodophyllotoxin. Cytotoxic activity of podophyllotoxin and selected leaf extracts of Juniperus sp. against a set of leukemia cell lines was demonstrated.

Bioactive metabolites from the fungus Nectria galligena, the main apple canker agent in Chile.

PubMed

Gutiérrez, Margarita; Theoduloz, Cristina; Rodríguez, Jaime; Lolas, Mauricio; Schmeda-Hirschmann, Guillermo

2005-10-05

The phytopathogenic fungus Nectria galligena Bres. is the most common canker disease agent of hardwood trees. The terpenoids colletochlorin B, colletorin B, ilicicolin C, E, and F, as well as the phytotoxin alpha,beta-dehydrocurvularin have been isolated from liquid cultures of N. galligena obtained from the xylem of infected apple trees in central Chile. Ilicicolin C and F and alpha,beta-dehydrocurvularin were active against Pseudomonas syringae with IC50 values of 28.5, 28.5, and 14.2 microg/mL, respectively, in the same range as streptomycin and penicillin G (11 and 15 microg/mL, respectively). All of the compounds showed moderate inhibitory activity toward the enzymes acetylcholinesterase (AChE) and beta-glucuronidase. The most active enzyme inhibitors were colletochlorin B and ilicicolin C and E, with IC50 values of 30-36 microg/mL in the AChE assay and 32-43 microg/mL in the beta-glucuronidase test. All of the chlorinated compounds showed some toxicity toward human lung fibroblasts, with IC50 values in the range of 64-120 microg/mL. alpha,beta-Dehydrocurvularin proved to be the most toxic compound, showing IC50 values less than 12 microg/mL. The effect of the isolated compounds on seed germination and radicle and epicotyl growth was assessed in lettuce and millet seeds. At 100 and 200 microg/disk, alpha,beta-dehydrocurvularin significantly reduced radicle length and epicotyl growth in Lactuca sativa. This is the first report on the occurrence of colletochlorin B, colletorin B, ilicicolin C, E, and F, as well as alpha,beta-dehydrocurvularin associated to N. galligena.

Identification of novel isoform-selective inhibitors within class I histone deacetylases.

PubMed

Hu, Erding; Dul, Edward; Sung, Chiu-Mei; Chen, Zunxuan; Kirkpatrick, Robert; Zhang, Gui-Feng; Johanson, Kyung; Liu, Ronggang; Lago, Amparo; Hofmann, Glenn; Macarron, Ricardo; de los Frailes, Maite; Perez, Paloma; Krawiec, John; Winkler, James; Jaye, Michael

2003-11-01

Histone deacetylases (HDACs) represent an expanding family of protein modifying-enzymes that play important roles in cell proliferation, chromosome remodeling, and gene transcription. We have previously shown that recombinant human HDAC8 can be expressed in bacteria and retain its catalytic activity. To further explore the catalytic activity of HDACs, we expressed two additional human class I HDACs, HDAC1 and HDAC3, in baculovirus. Recombinant HDAC1 and HDAC3 fusion proteins remained soluble and catalytically active and were purified to near homogeneity. Interestingly, trichostatin (TSA) was found to be a potent inhibitor for all three HDACs (IC50 value of approximately 0.1-0.3 microM), whereas another HDAC inhibitor MS-27-275 (N-(2-aminophenyl)-4-[N-(pyridin-3-methyloxycarbonyl)-aminomethyl]benzamide) preferentially inhibited HDAC1 (IC50 value of approximately 0.3 microM) versus HDAC3 (IC50 value of approximately 8 microM) and had no inhibitory activity toward HDAC8 (IC50 value >100 microM). MS-27-275 as well as TSA increased histone H4 acetylation, induced apoptosis in the human colon cancer cell line SW620, and activated the simian virus 40 early promoter. HDAC1 protein was more abundantly expressed in SW620 cells compared with that of HDAC3 and HDAC8. Using purified recombinant HDAC proteins, we identified several novel HDAC inhibitors that preferentially inhibit HDAC1 or HDAC8. These inhibitors displayed distinct properties in inducing histone acetylation and reporter gene expression. These results suggest selective HDAC inhibitors could be identified using recombinantly expressed HDACs and that HDAC1 may be a promising therapeutic target for designing HDAC inhibitors for proliferative diseases such as cancer.

Potent selective monoamine oxidase B inhibition by maackiain, a pterocarpan from the roots of Sophora flavescens.

PubMed

Lee, Hyun Woo; Ryu, Hyung Won; Kang, Myung-Gyun; Park, Daeui; Oh, Sei-Ryang; Kim, Hoon

2016-10-01

Monoamine oxidase (MAO) catalyzes the oxidation of monoamines and its two isoforms, MAO-A and MAO-B, break down neurotransmitter amines. Of the compounds isolated from the roots of Sophora flavescens, (-)-maackiain (4), a pterocarpan, was found to potently and selectively inhibit human MAO-B, with an IC50 of 0.68μM, and to have a selectivity index of 126.2 for MAO-B. As compared with other herbal natural products, the IC50 value of 4 for MAO-B is one of the lowest reported to date. Genistein (1) highly, effectively and non-selectively inhibited MAO-A and MAO-B with IC50 values of 3.9μM and 4.1μM, respectively. (-)-4-Hydroxy-3-methoxy-8,9-methylenedioxypterocarpan (2) effectively and non-selectively inhibited MAO-A and MAO-B with IC50 values of 20.3μM and 10.3μM, respectively. In addition, compound 4 reversibly and competitively inhibited MAO-B with a Ki value of 0.054μM. Molecular docking simulation revealed that the binding affinity of 4 for MAO-B (-26.6kcal/mol) was greater than its affinity for MAO-A (-8.3kcal/mol), which was in-line with our inhibitory activity findings. Furthermore, Cys172 of MAO-B was found to be a key residue for hydrogen bonding with compound 4. The findings of this study suggest compound 4 be viewed as a new potent, selective, and reversible MAO-B inhibitor, and that compounds 1 and 2 be considered useful lead compounds for the developments of nonselective and reversible MAO inhibitors for the treatment of disorders like Parkinson's disease, Alzheimer disease, and depression. Copyright © 2016 Elsevier Ltd. All rights reserved.

Pharmacologically relevant receptor binding characteristics and 5alpha-reductase inhibitory activity of free Fatty acids contained in saw palmetto extract.

PubMed

Abe, Masayuki; Ito, Yoshihiko; Oyunzul, Luvsandorj; Oki-Fujino, Tomomi; Yamada, Shizuo

2009-04-01

Saw palmetto extract (SPE), used widely for the treatment of benign prostatic hyperplasia (BPH) has been shown to bind alpha(1)-adrenergic, muscarinic and 1,4-dihydropyridine (1,4-DHP) calcium channel antagonist receptors. Major constituents of SPE are lauric acid, oleic acid, myristic acid, palmitic acid and linoleic acid. The aim of this study was to investigate binding affinities of these fatty acids for pharmacologically relevant (alpha(1)-adrenergic, muscarinic and 1,4-DHP) receptors. The fatty acids inhibited specific [(3)H]prazosin binding in rat brain in a concentration-dependent manner with IC(50) values of 23.8 to 136 microg/ml, and specific (+)-[(3)H]PN 200-110 binding with IC(50) values of 24.5 to 79.5 microg/ml. Also, lauric acid, oleic acid, myristic acid and linoleic acid inhibited specific [(3)H]N-methylscopolamine ([(3)H]NMS) binding in rat brain with IC(50) values of 56.4 to 169 microg/ml. Palmitic acid had no effect on specific [(3)H]NMS binding. The affinity of oleic acid, myristic acid and linoleic acid for each receptor was greater than the affinity of SPE. Scatchard analysis revealed that oleic acid and lauric acid caused a significant decrease in the maximal number of binding sites (B(max)) for [(3)H]prazosin, [(3)H]NMS and (+)-[(3)H]PN 200-110. The results suggest that lauric acid and oleic acid bind noncompetitively to alpha(1)-adrenergic, muscarinic and 1,4-DHP calcium channel antagonist receptors. We developed a novel and convenient method of determining 5alpha-reductase activity using LC/MS. With this method, SPE was shown to inhibit 5alpha-reductase activity in rat liver with an IC(50) of 101 microg/ml. Similarly, all the fatty acids except palmitic acid inhibited 5alpha-reductase activity, with IC(50) values of 42.1 to 67.6 microg/ml. In conclusion, lauric acid, oleic acid, myristic acid, and linoleic acid, major constituents of SPE, exerted binding activities of alpha(1)-adrenergic, muscarinic and 1,4-DHP receptors and inhibited 5alpha-reductase activity.

Pre-incubation with cyclosporine A potentiates its inhibitory effects on pitavastatin uptake mediated by recombinantly expressed cynomolgus monkey hepatic organic anion transporting polypeptide.

PubMed

Takahashi, Tsuyoshi; Ohtsuka, Tatsuyuki; Uno, Yasuhiro; Utoh, Masahiro; Yamazaki, Hiroshi; Kume, Toshiyuki

2016-11-01

Cyclosporine A, an inhibitor of hepatic organic anion transporting polypeptides (OATPs), reportedly increased plasma concentrations of probe substrates, although its maximum unbound blood concentrations were lower than the experimental half-maximal inhibitory (IC 50 ) concentrations. Pre-incubation with cyclosporine A in vitro before simultaneous incubation with probes has been reported to potentiate its inhibitory effects on recombinant human OATP-mediated probe uptake. In the present study, the effects of cyclosporine A and rifampicin on recombinant cynomolgus monkey OATP-mediated pitavastatin uptake were investigated in pre- and simultaneous incubation systems. Pre-incubation with cyclosporine A, but not with rifampicin, decreased the apparent IC 50 values on recombinant cynomolgus monkey OATP1B1- and OATP1B3-mediated pitavastatin uptake. Application of the co-incubated IC 50 values toward R values (1 + [unbound inhibitor] inlet to the liver, theoretically maximum /inhibition constant) in static models, 1.1 in monkeys and 1.3 in humans, for recombinant cynomolgus monkey and human OATP1B1-mediated pitavastatin uptake might result in the poor prediction of drug interaction magnitudes. In contrast, the lowered IC 50 values after pre-incubation with cyclosporine A provided better prediction with R values of 3.9 for monkeys and 2.7 for humans when the estimated maximum cyclosporine A concentrations at the inlet to the liver were used. These results suggest that the enhanced inhibitory potential of perpetrator medicines by pre-incubation on cynomolgus monkey OATP-mediated pitavastatin uptake in vitro could be of value for the precise estimation of drug interaction magnitudes in silico, in accordance with the findings from pre-administration of inhibitors on pitavastatin pharmacokinetics validated in monkeys. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Tyrosine-like condensed derivatives as tyrosinase inhibitors.

PubMed

Matos, Maria João; Santana, Lourdes; Uriarte, Eugenio; Serra, Silvia; Corda, Marcella; Fadda, Maria Benedetta; Era, Benedetta; Fais, Antonella

2012-05-01

We report the pharmacological evaluation of a new series of 3-aminocoumarins differently substituted with hydroxyl groups, which have been synthesized because they include in their structures the tyrosine fragment (tyrosine-like compounds), with the aim of discovering structural features necessary for tyrosinase inhibitory activity. The synthesized compounds 4 and 7-9 were evaluated in vitro as mushroom tyrosinase inhibitors. Two of the described compounds showed lower IC50 (concentration giving 50% inhibition of tyrosinase activity) than umbelliferone, used as a reference compound. Compound 7 (IC50=53µm) was the best tyrosinase inhibitor of this small series, having an IC50 value 10-fold lower than umbelliferone. Compound 7 (3-amino-7-hydroxycoumarin) had amino and hydroxyl groups precisely mimicking the same positions that both groups occupy on the tyrosine molecule. © 2012 The Authors. JPP © 2012 Royal Pharmaceutical Society.

The effect of brominated flame retardants on neurotransmitter uptake into rat brain synaptosomes and vesicles.

PubMed

Mariussen, Espen; Fonnum, Frode

2003-01-01

The environmental levels of brominated flame retardants (BFRs) are increasing, but little is known about their toxic effects. In this paper, we show that some of the most important BFRs in commercial use today, have a neurotoxicological potential. Hexabromocyclododecane (HBCD) and tetrabromobisphenol-A (TBBPA) inhibit plasma membrane uptake of the neurotransmitters dopamine, glutamate and gamma-amino-n-butyric acid (GABA) at a concentration level similar to what previously found for polychlorinated biphenyls (PCBs) and even for ecstasy. The IC(50) value for HBCD on dopamine uptake was 4 microM, and the IC(50) values for TBBPA were 9, 6 and 16 microM for dopamine, glutamate and GABA, respectively. HBCD also inhibited glutamate uptake at low concentrations, but never achieved more than 50% inhibition. The inhibition was primarily due to their effect on the membrane potential, measured by the membrane potential marker tetraphenylphosphonium bromide (TPP(+)). Other brominated flame retardants such as octaBDE and decaBDE did not have any effects on uptake. TBBPA, HBCD and even the pentabrominated diphenylether mixture (pentaBDE, DE-71, Great Lakes) also inhibited the vesicular uptake of dopamine with an IC(50) value of 3, 3 and 8 microM, respectively. The neurotoxicological consequences of these findings for environmental contaminants such as BFRs and PCBs are discussed.

The melanin synthesis inhibition and radical scavenging activities of compounds isolated from the aerial part of Lespedeza cyrtobotrya.

PubMed

Lee, Mi Yeon; Kim, Jin Hee; Choi, Jung Nam; Kim, Jiyoung; Hwang, Geum Sook; Lee, Choonghwan

2010-06-01

The EtOAc fraction of Lespedeza cyrtobotrya showed mushroom tyrosinase inhibitory and radical scavenging activity. Four active compounds were isolated based on LH-20 chromatography and HPLC, and the structures were elucidated on the basis of their LC-MS and NMR spectral data, as 2-(2,4-Dihydroxyphenyl)-6-hydroxybenzofuran (1), eriodictyol-7-O-glucopyranoside (2), haginin A (3), and dalbergioidin (4), respectively. 2-(2,4-Dihydroxyphenyl)-6-hydroxybenzofuran (1) showed mushroom tyrosinase inhibitory activity with an IC50 value of 5.2 micronM and acted as a competitive inhibitor. Furthermore, 37.3 micronM of compound 1 reduced 50 % of the melanin content on a human melanoma (MNT-1) cells. The radical scavenging activity of 2-(2,4-dihydroxyphenyl)-6-hydroxybenzofuran (1), eriodictyol-7-O-glucopyranoside (2), haginin A (3), and dalbergioidin (4) was shown with IC50 values of 11.0, 24.5, 9.0 and 36.5 micronM in an ABTS system and with IC50 values of 42.7, 36.0, 37.7 and 61.7 micronM in a DPPH system, respectively. The mushroom tyrosinase inhibitory activity of EtOAc fraction of Lespedeza cyrtobotrya was contributed by compound 1, 3 and 4, and radical scavenging activity of it was contributed by compound 1-4.

Protective effects of a standard extract of Mangifera indica L. (VIMANG) against mouse ear edemas and its inhibition of eicosanoid production in J774 murine macrophages.

PubMed

Garrido, G; González, D; Lemus, Y; Delporte, C; Delgado, R

2006-06-01

A standard aqueous extract of Mangifera indica L., used in Cuba as antioxidant under the brand name VIMANG, was tested in vivo for its anti-inflammatory activity, using commonly accepted assays. The standard extract of M. indica, administered orally (50-200mg/kg body wt.), reduced ear edema induced by arachidonic acid (AA) and phorbol myristate acetate (PMA) in mice. In the PMA model, M. indica extract also reduced myeloperoxidase (MPO) activity. In vitro studies were performed using macrophage cell line J774 stimulated with pro-inflammatory stimuli lipopolysaccharide-interferon gamma (LPS-IFNgamma) or calcium ionophore A23187 to determine prostaglandin PGE(2) or leukotriene LTB(4) release, respectively. The extract inhibited the induction of PGE(2) and LTB(4) with IC(50) values of 21.7 and 26.0microg/ml, respectively. Mangiferin (a glucosylxanthone isolated from the extract) also inhibited these AA metabolites (PGE(2), IC(50) value=17.2microg/ml and LTB(4), IC(50) value=2.1microg/ml). These results represent an important contribution to the elucidation of the mechanism involved in the anti-inflammatory and anti-nociceptive effects reported for the standard extract of M. indica VIMANG.

Chemical composition and cytotoxicity evaluation of essential oil from leaves of Casearia sylvestris, its main compound α-zingiberene and derivatives.

PubMed

Bou, Diego Dinis; Lago, João Henrique G; Figueiredo, Carlos R; Matsuo, Alisson L; Guadagnin, Rafael C; Soares, Marisi G; Sartorelli, Patricia

2013-08-08

Casearia sylvestris (Salicaceae), popularly known as "guaçatonga", is a plant widely used in folk medicine to treat various diseases, including cancer. The present work deals with the chemical composition as well as the cytotoxic evaluation of its essential oil, its main constituent and derivatives. Thus, the crude essential oil from leaves of C. sylvestris was obtained using a Clevenger type apparatus and analyzed by GC/MS. This analysis afforded the identification of 23 substances, 13 of which corresponded to 98.73% of the total oil composition, with sesquiterpene a-zingiberene accounting for 50% of the oil. The essential oil was evaluated for cytotoxic activity against several tumor cell lines, giving IC50 values ranging from 12 to 153 mg/mL. Pure a-zingiberene, isolated from essential oil, was also evaluated against the tumor cell lines showing activity for HeLa, U-87, Siha and HL60 cell lines, but with IC50 values higher than those determined for the crude essential oil. Aiming to evaluate the effect of the double bonds of a-zingiberene on the cytotoxic activity, partially hydrogenated a-zingiberene (PHZ) and fully hydrogenated a-zingiberene (THZ) derivatives were obtained. For the partially hydrogenated derivative only cytotoxic activity to the B16F10-Nex2 cell line (IC50 65 mg/mL) was detected, while totally hydrogenated derivative showed cytotoxic activity for almost all cell lines, with B16F10-Nex2 and MCF-7 as exceptions and with IC50 values ranging from 34 to 65 mg/mL. These results indicate that cytotoxic activity is related with the state of oxidation of compound.

The effects of a novel phosphodiesterase 7A and -4 dual inhibitor, YM-393059, on T-cell-related cytokine production in vitro and in vivo.

PubMed

Yamamoto, Satoshi; Sugahara, Shingo; Naito, Ryo; Ichikawa, Atsushi; Ikeda, Ken; Yamada, Toshimitsu; Shimizu, Yasuaki

2006-07-10

YM-393059, (+/-)-N-(4,6-dimethylpyrimidin-2-yl)-4-[2-(4-methoxy-3-methylphenyl)-5-(4-methylpiperazin-1-yl)-4,5,6,7-tetrahydro-1H-indol-1-yl]benzenesulfonamide difumarate, is a novel phosphodiesterase (PDE) inhibitor that inhibited the PDE7A isoenzyme with a high potency (IC50=14 nM) and PDE4 with a moderate potency (IC50=630 nM). In a cell-based assay, YM-393059 was found to inhibit anti-CD3 antibody, Staphylococcal enterotoxin B, and phytohaemagglutinin-induced interleukin (IL)-2 production in mouse splenocytes with IC50 values ranging from 0.48 to 1.1 microM. It also inhibited anti-CD3 antibody-induced interferon (IFN)-gamma and IL-4 production in splenocytes with IC50 values of 1.8 and 2.8 microM, respectively. YM-393059's inhibition of anti-CD3 antibody-stimulated cytokine (IL-2, IFN-gamma, and IL-4) production was 20- to 31-fold weaker than that of YM976, a selective PDE4 inhibitor. However, orally administered YM-393059 and YM976 inhibited anti-CD3 antibody-induced IL-2 production equipotently in mice. In addition, YM-393059 inhibited lipopolysaccharide-induced tumor necrosis factor-alpha production in vivo more potently than IL-2 (ED50 values of 2.1 mg/kg and 74 mg/kg). In contrast to YM976, YM-393059 did not shorten the duration of alpha2-adrenoceptor agonist-induced sleep in mice, which is a model for the assessment of the typical side effects caused by PDE4 inhibitors, nausea and emesis. YM-393059 is a novel and attractive compound for the treatment of a wide variety of T-cell-mediated diseases.

Anti-Proliferative Effect and Phytochemical Analysis of Cymbopogon citratus Extract

PubMed Central

Halabi, Mohammed F.; Sheikh, Bassem Y.

2014-01-01

The antiproliferative and antioxidant potential of Cymbopogon citratus (Lemon grass) extracts were investigated. The extracts were isolated by solvent maceration method and thereafter subjected to antiproliferative activity test on five different cancer cells: human colon carcinoma (HCT-116), breast carcinoma (MCF-7 and MDA-MB 231), ovarian carcinoma (SKOV-3 and COAV), and a normal liver cell line (WRL 68). The cell viability was determined using MTT assay. The DPPH radical scavenging assay revealed a concentration dependent trend. A maximum percentage inhibition of 45% and an IC50 of 278 μg/mL were observed when aqueous extract was evaluated. In contrast, 48.3% and IC50 of 258.9 μg/mL were observed when 50% ethanolic extract was evaluated. Both extracts at concentration of 50 to 800 μg/mL showed appreciative metal chelating activity with IC50 value of 172.2 ± 31 μg/mL to 456.5 ± 30 μg/mL. Depending on extraction solvent content, extract obtained from 50% ethanolic solvent proved to be more potent on breast cancer MCF-7 cell line (IC50 = 68 μg/mL). On the other hand, 90% ethanolic extract showed a moderate potency on the ovarian cancer (COAV) and MCF-7 cells having an IC50 of 104.6 μg/mL each. These results suggested antiproliferative efficacy of C. citratus ethanolic extract against human cancer cell lines. PMID:24791006

Anti-oxidant and anti-inflammatory activity of leaf extracts and fractions of Mangifera indica.

PubMed

Mohan, C G; Deepak, M; Viswanatha, G L; Savinay, G; Hanumantharaju, V; Rajendra, C E; Halemani, Praveen D

2013-04-13

To evaluate the anti-oxidant and anti-inflammatory activity of leaf extracts and fractions of Mangifera indica in in vitro conditions. In vitro DPPH radical scavenging activity and lipoxygenase (LOX) inhibition assays were used to evaluate the anti-oxidant and anti-inflammatory activities respectively. Methanolic extract (MEMI), successive water extract (SWMI) and ethyl acetate fraction (EMEMI), n-butanol fraction (BMEMI) and water soluble fraction (WMEMI) of methanolic extract were evaluated along with respective reference standards. In in vitro DPPH radical scavenging activity, the MEMI, EMEMI and BMEMI have offered significant antioxidant activity with IC(50) values of 13.37, 3.55 and 14.19 μg/mL respectively. Gallic acid, a reference standard showed significant antioxidant activity with IC(50) value of 1.88 and found to be more potent compared to all the extracts and fractions. In in vitro LOX inhibition assay, the MEMI, EMEMI and BMEMI have showed significant inhibition of LOX enzyme activity with IC(50) values of 96.71, 63.21 and 107.44 μg/mL respectively. While, reference drug Indomethacin also offered significant inhibition against LOX enzyme activity with IC(50) of 57.75. Furthermore, MEMI was found to more potent than SWMI and among the fractions EMEMI was found to possess more potent antioxidant and anti-inflammatory activity. These findings suggest that the MEMI and EMEMI possess potent anti-oxidant and anti-inflammatory activities in in vitro conditions. Copyright © 2013 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

Inhibitory activity of phenolic-rich pistachio green hull extract-enriched pasta on key type 2 diabetes relevant enzymes and glycemic index.

PubMed

Lalegani, Sajjad; Ahmadi Gavlighi, Hassan; Azizi, Mohammad Hossein; Amini Sarteshnizi, Roghayeh

2018-03-01

Phenolic compounds as agro-industrial by-products have been associated with health benefits since they exhibit high antioxidant activity and anti-diabetic properties. In this study, polyphenol-rich extract from pistachio green hull (PGH) was evaluated for antioxidant activity and its ability to inhibit α-amylase and α-glucosidase activity in vitro. The effect of PGH extract powder on in vitro starch digestibility was also evaluated. The results showed that PGH had stronger antioxidant activity than Trolox. The inhibitory effect of PGH extract against α-amylase from porcine pancreas was dose dependent and the IC 50 value was ~174μgGAE/mL. The crude PGH extract was eight times more potent on baker yeast α-glucosidase activity (IC 50 ~6μgGAE/mL) when compared to acarbose, whereas the IC 50 value of PGH extract against rat intestinal maltase activity obtained ~2.6mgGAE/mL. The non-tannin fraction of PGH extract was more effective against α-glucosidase than tannin fraction whereas the α-amylase inhibitor was concentrated in the tannin fraction. In vitro starch digestibility and glycemic index (GI) of pasta sample supplemented with PGH extract powder (1.5%) was significantly lower than the control pasta. The IC 50 value of PGH extract obtained from cooked pasta against α-amylase and α-glucosidase was increased. These results have important implications for the processing of PGH for food industry application and therefore could comply with glucose control diets. Copyright © 2017 Elsevier Ltd. All rights reserved.

Discovery of reversible DNA methyltransferase and lysine methyltransferase G9a inhibitors with antitumoral in vivo efficacy.

PubMed

Rabal, Obdulia; San José-Eneriz, Edurne; Agirre, Xabier; Sánchez-Arias, Juan A; Vilas-Zornoza, Amaia; Ugarte, Ana; De Miguel, Irene; Miranda, Estibaliz; Garate, Leire; Fraga, Mario; Santamarina, Pablo; Fernandez Perez, Raul; Ordoñez, Raquel; Sáez, Elena; Roa, Sergio; Garcia-Barchino, Maria Jose; Martinez-Climent, Jose Angel; Liu, Yingying; Wu, Wei; Xu, Musheng; Prosper, Felipe; Oyarzabal, Julen

2018-06-28

Using knowledge- and structure-based approaches, we designed and synthesized reversible chemical probes that simultaneously inhibit the activity of two epigenetic targets, histone 3 lysine 9 methyltransferase (G9a) and DNA methyltransferases (DNMT), at nanomolar ranges. Enzymatic competition assays confirmed our design strategy: substrate competitive inhibitors. Next, an initial exploration around our hit 11 was pursued to identify an adequate tool compound for in vivo testing. In vitro treatment of different hematological neoplasia cell lines led to the identification of molecules with clear anti-proliferative efficacies (GI50 values in the nanomolar range). Based on epigenetic functional cellular responses (levels of lysine 9 methylation and 5-methylcytosine), an acceptable therapeutic window (around 1 log unit) and a suitable pharmacokinetic profile, 12 was selected for in vivo proof-of-concept (ref 53). Herein, 12 achieved a significant in vivo efficacy: 70% overall tumor growth inhibition of a human AML (Acute Myeloid Leukemia) xenograft in a mouse model.

A new inositol triester from Taraxacum mongolicum.

PubMed

Liu, Jifeng; Zhang, Nenling; Liu, Mengqi

2014-01-01

One new inositol triester, 4,5,6-tri-O-p-hydroxyphenylacetyl-chiro-inositol (1), was isolated from the ethanolic extract of Taraxacum mongolicum, along with two known compounds, 11β,13-dihydrotaraxinic acid (2) and taraxinic acid β-d-glucopyranosyl ester (3). The isolates were tested for their anti-hepatitis B virus (HBV) activities; 11β,13-dihydrotaraxinic acid (2) exhibited an IC50 value of 0.91 mM inhibiting the secretion of the HBV surface antigen and an IC50 value of 0.34 mM inhibiting the secretion of the HBV e antigen using HBV transfected Hep G2.2.15 cell line.

Chemistry and biological activity of coumarins at molecular level.

PubMed

Garro, Hugo A; García, Celina; Martín, Víctor S; Tonn, Carlos E; Pungitore, Carlos R

2014-08-01

Synthetic coumarins were prepared in high yields using ionic liquids as an environmental friendly alternative. 3,4-Dimethyl-7-hydroxycoumarin (3ab) and 3-isopropyl-4-methyl-5,7-dihydroxycoumarin (3bc) showed interesting activity against Taq DNA polymerase with IC50 values of 115.7 microM and 82.2 microM, respectively. Also, 4-methyl-7-hydroxycoumarin (3aa) and 4-methyl-5,7-dihydroxycoumarin (3ba) exhibited inhibitory activity against MMLV-RT with IC50 values of 23.5 microM and 18.3 microM, respectively. These inhibitors could have importance as antiretroviral chemotherapeutic agents and also for the development of antitumor drugs.

Colletotrilactam A-D, novel lactams from Colletotrichum gloeosporioides GT-7, a fungal endophyte of Uncaria rhynchophylla.

PubMed

Wei, Bo; Yang, Zhong-Duo; Chen, Xiao-Wei; Zhou, Shuang-Yan; Yu, Hai-Tao; Sun, Jing-Yun; Yao, Xiao-Jun; Wang, Yong-Gang; Xue, Hong-Yan

2016-09-01

Four novel lactams, colletotrilactam A-D (1-4), along with six known compounds (5-10) were isolated from the culture broth of Colletotrichum gloeosporioides GT-7, a fungal endophyte of Uncaria rhynchophylla. The structures of these compounds were elucidated by comprehensive NMR spectroscopy. Isolates were tested for monoamine oxidase (MAO) inhibitory activity and compound 9 showed potent MAO inhibitory activity with IC50 value of 8.93±0.34μg/mL, when the IC50 value of iproniazid as a standard was 1.80±0.5μg/mL. Copyright © 2016 Elsevier B.V. All rights reserved.

Inhibition of phospholipase cgamma1 and cancer cell proliferation by triterpene esters from Uncaria rhynchophylla.

PubMed

Lee, J S; Kim, J; Kim, B Y; Lee, H S; Ahn, J S; Chang, Y S

2000-06-01

Investigation of the hooks of Uncaria rhynchophylla resulted in isolation of six phospholipase Cgamma1 (PLCgamma1) inhibitors (1-6). The structures of these compounds were elucidated as pentacyclic triterpene esters by spectroscopic and chemical analysis. Three of them, namely uncarinic acids C (1), D (2), and E (3), are newly reported as natural products. All the compounds showed dose-dependent inhibitory activities against PLCgamma1 in vitro with IC(50) values of 9.5-44.6 microM and inhibited the proliferation of human cancer cells with IC(50) values of 0.5-6.5 microg/mL.

Four new compounds isolated from Psoralea corylifolia and their diacylglycerol acyltransferase (DGAT) inhibitory activity.

PubMed

Lin, Xin; Li, Ban-Ban; Zhang, Le; Li, Hao-Ze; Meng, Xiao; Jiang, Yi-Yu; Lee, Hyun-Sun; Cui, Long

2018-05-14

A new bakuchiol compound Δ 11 -12-hydroxy-12-dimethyl bakuchiol (1), a new flavanone compound 2(S)-6-methoxy-7- hydroxymethylene-4'-hydroxyl-flavanone (8), and two new isoflavanone compounds 4',7-dihydroxy-3'-(6"β-hydroxy-3″,7″-dimethyl-,2″,7″-dibutenyl)-geranylisoflavone (9) and 4',7-dihydroxy-3'-(7″-hydroxy-7″-methyl-2″,5″-dibutenyl)-geranylisoflavone (10) together with eight known compounds (2-7, 11, 12) were isolated from the P. corylifolia. Their structures were elucidated on the basis of spectroscopic and physico-chemical analyses. All the isolates were evaluated for in vitro inhibitory activity against DGAT1/2. Among them, compounds 3, 9 and 10 were found to exhibit selective inhibitory activity on DGAT1 with IC 50 values ranging from 93.7 ± 1.3 to 96.2 ± 1.1 μM. Compound 1 showed inhibition activity on DGAT1 with IC 50 values 73.4 ± 1.3 μM and inhibition of DGAT2 with IC 50 value 121.1 ± 1.3 μM. Copyright © 2018 Elsevier B.V. All rights reserved.

Antidiabetic potential of Caesalpinia sumatrana, a medicinal herbs traditionally used by local tribe in East Kalimantan

NASA Astrophysics Data System (ADS)

Wicaksono, D. A.; Rosamah, E.; Kusuma, I. W.

2018-04-01

The aims of the research was to analyze the content of phytochemicals, to examine the antioxidant and antidiabeticpotentials of n-hexane, chloroform, ethyl acetate, and ethanol extracts of Caesalpinia sumatrana. Method to measure antioxidant capacity of sample involves the use of the free radical, 1,1-diphenyl-2-picrylhydrazyl (DPPH) which is widely used to test the ability of compounds to act as free radical. Analysis the potential of antidiabeticactivity of the extracts was determined by α-glucosidase and α-amylase inhibitory assay. Of all extracts obtained by successive maceration, ethanol maceration gave the highest extract by 2.63% of extract on the dry weigh basis. The result of phytochemicals showed that all extracts contain alkaloid and flavonoid. The highest antioxidant activity was 82.32% with IC50 value of 5.00 µg/ml obtained by ethanol extract. The results of enzyme inhibitory assay of α-glucosidase showed that ethanol extract of C. sumatrana had IC50 value 17.16 µg/mL to inhibit ɑ-glucosidase activity and IC50 value 16.78 µg/mL for ɑ-amylase. The present result displayed potential of the plant to be developed as natural antidiabetic and antioxidant agents.

Cyclopentenone derivatives and polyhydroxylated steroids from the soft coral Sinularia acuta.

PubMed

Zhang, Nai-Xia; Tang, Xu-Li; van Ofwegen, Leen; Xue, Lei; Song, Wen-Juan; Li, Ping-Lin; Li, Guo-Qiang

2015-02-01

Four new polyhydroxylated steroids, 1-4, and the racemic form of cyclopentenone 9, together with four known steroids, 5-8, one known cyclopentenone derivative, 10, and one known butenolide derivative, 11, were isolated from the soft coral Sinularia acuta collected from Weizhou Island of Guangxi Province, P. R. China. Their structures were elucidated on the basis of spectroscopic analyses and by comparison of the corresponding data with those previously reported. The cytotoxicities of the isolates 1-11 in vitro against the selected tumor cell lines HL-60, HeLa, and K562 were evaluated. Compounds 2 and 5 showed potent cytotoxicities against HL-60 cell lines with IC50 values of 7.3 and 9.9 μM, respectively. Compounds 5 and 6 showed moderate activities against K562 cell lines with IC50 values of 10.9 and 11.7 μM, respectively, while compounds 1, 2, and 6 showed weak activities against HeLa cell lines with respective IC50 values of 44.8, 27.1, and 18.2 μM. This is the first report on chemical and bioactivity research of S. acuta. Copyright © 2015 Verlag Helvetica Chimica Acta AG, Zürich.

Purification, characterization, and biological activities of broccolini lectin.

PubMed

Xu, Pingping; Zhang, Ting; Guo, Xiaolei; Ma, Chungwah; Zhang, Xuewu

2015-01-01

Plant lectins have displayed a variety of biological activities. In this study, for the first time, a 27 kDa arabinose- and mannose-specific lectin from Broccolini (Brassica oleracea Italica × Alboglabra), named as BL (Broccolini lectin), was purified by an activity-driven protocol. Mass spectrometry analysis and database search indicated that no matches with any plant lectin were found, but BL contained some peptide fragments (QQQGQQGQQLQQVISR, QQGQQQGQQGQQLQQVISR and VCNIPQVSVCPF QK). BL exhibited hemagglutinating activity against chicken erythrocytes at 4 µg/mL. BL retained full hemagglutinating activity at pH 7-8 and temperature 30-40°C, and had an optimal activity in Ca(2+) solution. Bioactivity assay revealed that BL exhibited dose-dependent inhibition activity on 5 bacterial species with IC50 values of 143.95-486.33 μg/mL, and on 3 cancer cells with IC50 values of 178.82-350.93 μg/mL. Notably, 5-fold reduction in IC50 values was observed on normal L-O2 vs cancerous HepG-2 cells (924.35 vs. 178.82 μg/mL). This suggests that BL should be promising in food and medicine. © 2015 American Institute of Chemical Engineers.

Urease inhibitory profile of extracts and chemical constituents of Pistacia atlantica ssp. cabulica Stocks.

PubMed

Uddin, Ghias; Ismail; Rauf, Abdur; Raza, Muslim; Khan, Haroon; Nasruddin; Khan, Majid; Farooq, Umar; Khan, Ajmal; Arifullah

2016-06-01

The current study was designed to evaluate the urease inhibitory profile of extract and fractions of Pistacia atlantica ssp. cabulica Stocks followed by bioactivity-guided isolated compounds. The crude extract was found significantly active with urease inhibitor (95.40% at 0.2 mg/mL) with IC50 values of 32.0 ± 0.28 μg/mL. Upon fractionation, ethyl acetate fraction displayed 100% urease inhibition with IC50 values of 19.9 ± 0.51 μg/mL at 0.2 mg/mL. However, n-hexane and chloroform fractions exhibited insignificant urease inhibition. Similarly, the isolated compound, transilitin (1) and dihydro luteolin (2) demonstrated marked urease attenuation with 95 and 98% respectively, at 0.15 mg/mL. Both the isolated compounds showed marked potency with IC50 values of 8.54 ± 0.54 and 9.58 ± 2.22 μg/mL, respectively. In short, both the extract and fractions and isolated compounds showed marked urease inhibition and thus a useful natural source of urease inhibition.

Antitumor, Antioxidant, and Nitrite Scavenging Effects of Chinese Water Chestnut (Eleocharis dulcis) Peel Flavonoids.

PubMed

Zhan, Ge; Pan, Leiqing; Tu, Kang; Jiao, Shunshan

2016-10-01

The preparation, quantification, and characterization of flavonoid compounds from Chinese water chestnut peel (CWCP) flavonoid extract and ethyl acetate fraction (EF), n-butanol fraction, and water fraction were studied. Among these, EF showed the maximum free radical levels (IC 50 values of 0.36, 0.40, and 0.37 mg/mL for DPPH•, ABTS• + , and •OH, respectively), nitrite scavenging effects (IC 50 = 1.89 mg/mL), and A549 cell inhibitory activities (IC 50 = 776.12 μg/mL) with the highest value of total flavonoid content (TFC, 421.32 mg/g). Moreover, the contents of 8 flavonoids in this fraction were quantified using high-performance liquid chromatography, and fisetin, diosmetin, luteolin, and tectorigenin were the 4 major flavonoids with levels of 31.66, 29.91, 13.69, and 12.41 mg/g, respectively. Luteolin produced a greater inhibition of human lung cancer A549 cells (IC 50 = 59.60 μg/mL) than did fisetin, diosmetin, and tectorigenin. Flow cytometry revealed that the cellular mechanisms of luteolin inhibition of A549 cells were achieved via the induction of cell proliferation arrest at G 1 phase and apoptosis/necrosis. Our findings suggest that flavonoids are closely associated with antitumor, antioxidant, and nitrite scavenging effects of CWCP. © 2016 Institute of Food Technologists®.

Dihydropyrimidones: As novel class of β-glucuronidase inhibitors.

PubMed

Ali, Farman; Khan, Khalid Mohammed; Salar, Uzma; Iqbal, Sarosh; Taha, Muhammad; Ismail, Nor Hadiani; Perveen, Shahnaz; Wadood, Abdul; Ghufran, Mehreen; Ali, Basharat

2016-08-15

Dihydropyrimidones 1-37 were synthesized via a 'one-pot' three component reaction according to well-known Biginelli reaction by utilizing Cu(NO3)2·3H2O as catalyst, and screened for their in vitro β-glucuronidase inhibitory activity. It is worth mentioning that amongst the active molecules, compounds 8 (IC50=28.16±.056μM), 9 (IC50=18.16±0.41μM), 10 (IC50=22.14±0.43μM), 13 (IC50=34.16±0.65μM), 14 (IC50=17.60±0.35μM), 15 (IC50=15.19±0.30μM), 16 (IC50=27.16±0.48μM), 17 (IC50=48.16±1.06μM), 22 (IC50=40.16±0.85μM), 23 (IC50=44.16±0.86μM), 24 (IC50=47.16±0.92μM), 25 (IC50=18.19±0.34μM), 26 (IC50=33.14±0.68μM), 27 (IC50=44.16±0.94μM), 28 (IC50=24.16±0.50μM), 29 (IC50=34.24±0.47μM), 31 (IC50=14.11±0.21μM) and 32 (IC50=9.38±0.15μM) found to be more potent than the standard d-saccharic acid 1,4-lactone (IC50=48.4±1.25μM). Molecular docking study was conducted to establish the structure-activity relationship (SAR) which demonstrated that a number of structural features of dihydropyrimidone derivatives were involved to exhibit the inhibitory potential. All compounds were characterized by spectroscopic techniques such as (1)H, (13)C NMR, EIMS and HREI-MS. Copyright © 2016 Elsevier Ltd. All rights reserved.

Design, synthesis, crystallization and biological evaluation of new symmetrical biscationic compounds as selective inhibitors of human Choline Kinase α1 (ChoKα1)

NASA Astrophysics Data System (ADS)

Schiaffino-Ortega, Santiago; Baglioni, Eleonora; Mariotto, Elena; Bortolozzi, Roberta; Serrán-Aguilera, Lucía; Ríos-Marco, Pablo; Carrasco-Jimenez, M. Paz; Gallo, Miguel A.; Hurtado-Guerrero, Ramon; Marco, Carmen; Basso, Giuseppe; Viola, Giampietro; Entrena, Antonio; López-Cara, Luisa Carlota

2016-03-01

A novel family of compounds derivative of 1,1‧-(((ethane-1,2-diylbis(oxy))bis(4,1-phenylene))bis(methylene))-bispyridinium or -bisquinolinium bromide (10a-l) containing a pair of oxygen atoms in the spacer of the linker between the biscationic moieties, were synthesized and evaluated as inhibitors of choline kinase against a panel of cancer-cell lines. The most promising compounds in this series were 1,1‧-(((ethane-1,2-diylbis(oxy))bis(4,1-phenylene))bis(methylene))bis(4-(dimethylamino)pyridinium) bromide (10a) and 1,1‧-(((ethane-1,2-diylbis(oxy))bis(4,1-phenylene))bis(methylene))-bis(7-chloro-4-(pyrrolidin-1-yl)quinolinium) bromide (10l), which inhibit human choline kinase (ChoKα1) with IC50 of 1.0 and 0.92 μM, respectively, in a range similar to that of the previously reported biscationic compounds MN58b and RSM932A. Our compounds show greater antiproliferative activities than do the reference compounds, with unprecedented values of GI50 in the nanomolar range for several of the cancer-cell lines assayed, and more importantly they present low toxicity in non-tumoral cell lines, suggesting a cancer-cell-selective antiproliferative activity. Docking studies predict that the compounds interact with the choline-binding site in agreement with the binding mode of most previously reported biscationic compounds. Moreover, the crystal structure of ChoKα1 with compound 10a reveals that this compound binds to the choline-binding site and mimics HC-3 binding mode as never before.

In vitro antiprotozoan activity and mechanisms of action of selected Ghanaian medicinal plants against Trypanosoma, Leishmania, and Plasmodium parasites.

PubMed

Ohashi, Mitsuko; Amoa-Bosompem, Michael; Kwofie, Kofi Dadzie; Agyapong, Jefferey; Adegle, Richard; Sakyiamah, Maxwell Mamfe; Ayertey, Frederick; Owusu, Kofi Baffuor-Awuah; Tuffour, Isaac; Atchoglo, Philip; Tung, Nguyen Huu; Uto, Takuhiro; Aboagye, Frederick; Appiah, Alfred Ampomah; Appiah-Opong, Regina; Nyarko, Alexander K; Anyan, William Kofi; Ayi, Irene; Boakye, Daniel Adjei; Koram, Kwadwo Ansah; Edoh, Dominic; Yamaoka, Shoji; Shoyama, Yukihiro; Ohta, Nobuo

2018-05-07

Trypanosomiasis, leishmaniasis, and malaria are protozoan infections of public health importance with thousands of new cases recorded annually. Control of these infection(s) with existing chemotherapy is limited by drug toxicity, lengthy parenteral treatment, affordability, and/or the emergence of resistant strains. Medicinal plants on the other hand are used in the treatment of various infectious diseases although their chemical properties are not fully evaluated. In this study, we screened 112 crude extracts from 72 selected Ghanaian medicinal plants for anti-Trypanosoma, anti-Leishmania, and anti-Plasmodium activities in vitro and investigated their mechanisms of action. Twenty-three extracts from 20 plants showed significant antiprotozoan activity against at least 1 of 3 protozoan parasites screened with IC 50 values less than 20 μg/ml. Eleven extracts showed high anti-Trypanosoma activity with Bidens pilosa whole plant and Morinda lucida leaf extracts recording the highest activities. Their IC 50 (selectivity index [SI]) values were 5.51 μg/ml (35.00) and 5.96 μg/ml (13.09), respectively. Nine extracts had high anti-Leishmania activity with Annona senegalensis and Cassia alata leaf extracts as the most active. Their IC 50 (SI) values were 10.8 μg/ml (1.50) and 10.1 μg/ml (0.37), respectively. Six extracts had high anti-Plasmodium activity with the leaf and stem-bark extracts of Terminalia ivorensis recording the highest activity. Their IC 50 (SI) values were 7.26 μg/ml (129.36) and 17.45 μg/ml (17.17), respectively. Only M. lucida at 25 μg/ml induced significant apoptosis-like cell death in Trypanosoma parasites. Anti-Leishmania active extracts induced varying morphological changes in Leishmania parasites such as multiple nuclei and/or kinetoplast, incomplete flagella division, or nuclear fragmentation. Active extracts may be potential sources for developing new chemotherapy against these infections. Copyright © 2018 John Wiley & Sons, Ltd.

Phytochemical and cytotoxic studies on the leaves of Calotropis gigantea.

PubMed

Nguyen, Khang D H; Dang, Phu H; Nguyen, Hai X; Nguyen, Mai T T; Awale, Suresh; Nguyen, Nhan T

2017-07-01

A new lignan, 9'-methoxypinoresinol (1), and two new glycosylated 5-hydroxymethylfurfurals, calofurfuralside A (2), and calofurfuralside B (3), together with nine known compounds (4-12) have been isolated from the active fractions, CHCl 3 (IC 50 , 0.32μgmL -1 ) and EtOAc (IC 50 , 0.55μgmL -1 ) fractions of the leaves of Calotropis gigantea. Their structures were elucidated based on NMR and MS data. Among the isolated compounds, compounds 1 and 9 exhibited potent cytotoxicity against PANC-1 human pancreatic cancer cell line under the normoglycemic condition with IC 50 values of 3.7 and 3.3μM, respectively. 9'-Methoxypinoresinol (1) significantly inhibited the colony formation of PANC-1 cells in a concentration-dependent manner. Copyright © 2017 Elsevier Ltd. All rights reserved.

Phenoxyacetohydrazide Schiff bases: β-glucuronidase inhibitors.

PubMed

Jamil, Waqas; Perveen, Shagufta; Shah, Syed Adnan Ali; Taha, Muhammad; Ismail, Nor Hadiani; Perveen, Shahnaz; Ambreen, Nida; Khan, Khalid M; Choudhary, Muhammad I

2014-06-25

Phenoxyacetohydrazide Schiff base analogs 1-28 have been synthesized and their in vitro β-glucouoronidase inhibition potential studied. Compounds 1 (IC50=9.20±0.32 µM), 5 (IC50=9.47±0.16 µM), 7 (IC50=14.7±0.19 µM), 8 (IC50=15.4±1.56 µM), 11 (IC50=19.6±0.62 µM), 12 (IC50=30.7±1.49 µM), 15 (IC50=12.0±0.16 µM), 21 (IC50=13.7±0.40 µM) and 22 (IC50=22.0±0.14 µM) showed promising β-glucuronidase inhibition activity, better than the standard (D-saccharic acid-1,4-lactone, IC50=48.4±1.25 µM).

Drug Synergy of Tenofovir and Nanoparticle-Based Antiretrovirals for HIV Prophylaxis

PubMed Central

Chaowanachan, Thanyanan; Krogstad, Emily; Ball, Cameron; Woodrow, Kim A.

2013-01-01

Background The use of drug combinations has revolutionized the treatment of HIV but there is no equivalent combination product that exists for prevention, particularly for topical HIV prevention. Strategies to combine chemically incompatible agents may facilitate the discovery of unique drug-drug activities, particularly unexplored combination drug synergy. We fabricated two types of nanoparticles, each loaded with a single antiretroviral (ARV) that acts on a specific step of the viral replication cycle. Here we show unique combination drug activities mediated by our polymeric delivery systems when combined with free tenofovir (TFV). Methodology/Principal Findings Biodegradable poly(lactide-co-glycolide) nanoparticles loaded with efavirenz (NP-EFV) or saquinavir (NP-SQV) were individually prepared by emulsion or nanoprecipitation techniques. Nanoparticles had reproducible size (d ∼200 nm) and zeta potential (-25 mV). The drug loading of the nanoparticles was approximately 7% (w/w). NP-EFV and NP-SQV were nontoxic to TZM-bl cells and ectocervical explants. Both NP-EFV and NP-SQV exhibited potent protection against HIV-1 BaL infection in vitro. The HIV inhibitory effect of nanoparticle formulated ARVs showed up to a 50-fold reduction in the 50% inhibitory concentration (IC50) compared to free drug. To quantify the activity arising from delivery of drug combinations, we calculated combination indices (CI) according to the median-effect principle. NP-EFV combined with free TFV demonstrated strong synergistic effects (CI50 = 0.07) at a 1∶50 ratio of IC50 values and additive effects (CI50 = 1.05) at a 1∶1 ratio of IC50 values. TFV combined with NP-SQV at a 1∶1 ratio of IC50 values also showed strong synergy (CI50 = 0.07). Conclusions ARVs with different physicochemical properties can be encapsulated individually into nanoparticles to potently inhibit HIV. Our findings demonstrate for the first time that combining TFV with either NP-EFV or NP-SQV results in pronounced combination drug effects, and emphasize the potential of nanoparticles for the realization of unique drug-drug activities. PMID:23630586

Profiling the anti-protozoal activity of anti-cancer HDAC inhibitors against Plasmodium and Trypanosoma parasites.

PubMed

Engel, Jessica A; Jones, Amy J; Avery, Vicky M; Sumanadasa, Subathdrage D M; Ng, Susanna S; Fairlie, David P; Skinner-Adams, Tina; Andrews, Katherine T

2015-12-01

Histone deacetylase (HDAC) enzymes work together with histone acetyltransferases (HATs) to reversibly acetylate both histone and non-histone proteins. As a result, these enzymes are involved in regulating chromatin structure and gene expression as well as other important cellular processes. HDACs are validated drug targets for some types of cancer, with four HDAC inhibitors clinically approved. However, they are also showing promise as novel drug targets for other indications, including malaria and other parasitic diseases. In this study the in vitro activity of four anti-cancer HDAC inhibitors was examined against parasites that cause malaria and trypanosomiasis. Three of these inhibitors, suberoylanilide hydroxamic acid (SAHA; vorinostat(®)), romidepsin (Istodax(®)) and belinostat (Beleodaq(®)), are clinically approved for the treatment of T-cell lymphoma, while the fourth, panobinostat, has recently been approved for combination therapy use in certain patients with multiple myeloma. All HDAC inhibitors were found to inhibit the growth of asexual-stage Plasmodium falciparum malaria parasites in the nanomolar range (IC50 10-200 nM), while only romidepsin was active at sub-μM concentrations against bloodstream form Trypanosoma brucei brucei parasites (IC50 35 nM). The compounds were found to have some selectivity for malaria parasites compared with mammalian cells, but were not selective for trypanosome parasites versus mammalian cells. All compounds caused hyperacetylation of histone and non-histone proteins in P. falciparum asexual stage parasites and inhibited deacetylase activity in P. falciparum nuclear extracts in addition to recombinant PfHDAC1 activity. P. falciparum histone hyperacetylation data indicate that HDAC inhibitors may differentially affect the acetylation profiles of histone H3 and H4.

A Stabilized Demethoxyviridin Derivative Inhibits PI3 kinase

PubMed Central

Yuan, Hushan; Pupo, Monica T.; Blois, Joe; Smith, Adam; Weissleder, Ralph; Clardy, Jon; Josephson, Lee

2009-01-01

The viridins like demethoxyviridin (Dmv) and wortmannin (Wm) are nanomolar inhibitors of the PI3 kinases, a family of enzymes that play key roles in a host of regulatory processes. Central to the use of these compounds to investigate the role of PI3 kinase in biological systems, or as scaffolds for drug development, are the interrelated issues of stability, chemical reactivity, and bioactivity as inhibitors of PI3 kinase. We found that Dmv was an even more potent inhibitor of PI3 kinase than Wm. However, Dmv was notably less stable than Wm in PBS, with a half-life of 26 min vs Wm’s half-life of 3470 min. Dmv, like Wm, disappeared in culture media with a half-life of less than 1 min. To overcome Dmv’s instability, it was esterified at the C1 position, and then reacted with glycine at the C20 position. The resulting Dmv derivative, termed SA-DmvC20-Gly had a half-life of 218 min in PBS and 64 min in culture media. SA-DmvC20-Gly underwent an exchange reaction at the C20 position with N-acetyl lysine in a manner similar to a WmC20 derivative, WmC20-Proline. SA-DmvC20-Gly inhibited PI3 kinase with an IC50 of 44 nM, compared to Wm’s IC50 of 12 nM. These results indicate that the stability of Dmv can be manipulated by reactions at the C1 and C20 positions, while substantially maintaining its ability to inhibit PI3 kinase. Our results indicate it may be possible to obtain stabilized Dmv derivatives for use as PI3 kinase inhibitors in biological systems. PMID:19523825

Bacterial Infochemicals are Drivers of Algal Lysis

NASA Astrophysics Data System (ADS)

Whalen, K.; Deering, R.; Rowley, D. C.; El Gamal, A.; Schorn, M.; Moore, B. S.; Johnson, M. D.; Mincer, T. J.; Harvey, E.

2016-02-01

Processing of organic matter by bacteria forces oceanic biogeochemical cycles, food web structure and ultimately environmental stoichiometry. A newly emerging picture of the microbial loop suggests that bacteria are not merely passive recipients of dissolved organic matter (DOM) from phytoplankton exudate. Rather, heterotrophic bacteria can mediate the flow of DOM by actively producing soluble algicidal compounds. However, deciphering those chemical signals that determine these interactions has remained a challenge. Here, we report the isolation of 2-heptyl-4-quinolone (HHQ), released by Pseudoalteromonas piscicida, a marine gamma-proteobacteria isolated from plastic debris in the North Atlantic. Both 2-heptyl-3-hydroxy-4-quinolone and its immediate precursor, HHQ are known to function as antibiotics and quorum sensing signaling molecules with crucial roles in virulence, and apoptosis in eukaryotic cells (e.g. fungi and mammalian cells). Our ecologically-relevant screening of live cells and filtrate from P. piscicida cultures caused a significant decrease in the growth rate of the bloom-forming coccolithophore, Emiliania huxleyi. Bioassay-guided fraction of P. piscicida extracellular crude extracts identified HHQ, which induced mortality in three strains of E. huxleyi with an IC50 in the nanomolar range. In contrast, the marine chlorophyte, Dunaliella tertiolecta and diatom, Phaeodactylum tricornutum were unaffected by HHQ exposures (IC50 > 10 micromolar), but were susceptible to extracts of P. piscicida, indicating this bacterium may produce a cocktail of algicidal compounds specific to different phytoplankton guilds. The ability of HHQ to influence phytoplankton growth suggests that alkylquinolone-signaling molecules play a fundamental role in interkingdom interactions, ultimately influencing shifts in phytoplankton population dynamics. This study implicates a new role for HHQ beyond its importance in quorum sensing.

Synthesis of 6-chloro-2-Aryl-1H-imidazo[4,5-b]pyridine derivatives: Antidiabetic, antioxidant, β-glucuronidase inhibiton and their molecular docking studies.

PubMed

Taha, Muhammad; Ismail, Nor Hadiani; Imran, Syahrul; Rashwan, Hesham; Jamil, Waqas; Ali, Sajjad; Kashif, Syed Muhammad; Rahim, Fazal; Salar, Uzma; Khan, Khalid Mohammed

2016-04-01

6-Chloro-2-Aryl-1H-imidazo[4,5-b]pyridine derivatives 1-26 were synthesized and characterized by various spectroscopic techniques. All these derivatives were evaluated for their antiglycation, antioxidant and β-glucuronidase potential followed their docking studies. In antiglycation assay, compound 2 (IC50=240.10±2.50μM) and 4 (IC50=240.30±2.90μM) was found to be most active compound of this series, while compounds 3 (IC50=260.10±2.50μM), 6 (IC50=290.60±3.60μM), 13 (IC50=288.20±3.00μM) and 26 (IC50=292.10±3.20μM) also showed better activities than the standard rutin (IC50=294.50±1.50μM). In antioxidant assay, compound 1 (IC50=69.45±0.25μM), 2 (IC50=58.10±2.50μM), 3 (IC50=74.25±1.10μM), and 4 (IC50=72.50±3.30μM) showed good activities. In β-glucuronidase activity, compounds 3 (IC50=29.25±0.50μM), compound 1 (IC50=30.10±0.60μM) and compound 4 (IC50=46.10±1.10μM) showed a significant activity as compared to than standard D-Saccharic acid 1,4-lactonec (IC50=48.50±1.25μM) and their interaction with the enzyme was confirm by docking studies. Copyright © 2016 Elsevier Inc. All rights reserved.

Prediction of kinase-inhibitor binding affinity using energetic parameters

PubMed Central

Usha, Singaravelu; Selvaraj, Samuel

2016-01-01

The combination of physicochemical properties and energetic parameters derived from protein-ligand complexes play a vital role in determining the biological activity of a molecule. In the present work, protein-ligand interaction energy along with logP values was used to predict the experimental log (IC50) values of 25 different kinase-inhibitors using multiple regressions which gave a correlation coefficient of 0.93. The regression equation obtained was tested on 93 kinase-inhibitor complexes and an average deviation of 0.92 from the experimental log IC50 values was shown. The same set of descriptors was used to predict binding affinities for a test set of five individual kinase families, with correlation values > 0.9. We show that the protein-ligand interaction energies and partition coefficient values form the major deterministic factors for binding affinity of the ligand for its receptor. PMID:28149052

Desacetylmatricarin, an anti-allergic component from Taraxacum platycarpum.

PubMed

Cheong, H; Choi, E J; Yoo, G S; Kim, K M; Ryu, S Y; Ho, C

1998-08-01

The bioassay-guided fractionation of Taraxacum platycarpum (Compositae) extract led to the isolation of a desacetylmatricarin (1) as an active principle responsible for the anti-allergic property. It showed a potent inhibitory activity upon the beta-hexosaminidase release from RBL-2H3 cells in a dose-dependent manner and the IC50 was 7.5 microM. Two structurally related guaianolide sesquiterpenes, achillin and leucodin, were also examined and their IC50 values were determined as 100 microM and 80 microM, respectively.

Inhibition of tyrosinase activity and melanine pigmentation by 2-hydroxytyrosol

PubMed Central

Uchida, Ryuji; Ishikawa, Seiko; Tomoda, Hiroshi

2014-01-01

2-Hydroxytyrosol (2-HT), originally reported as a synthetic compound, was isolated for the first time as a fungal metabolite. 2-HT was found to inhibit mushroom tyrosinase with an IC50 value of 13.0 µmol/L. Furthermore, 2-HT dose-dependently inhibited tyrosinase activity (IC50, 32.5 µmol/L) in the cell-free extract of B16 melanoma cells and α-melanocyte stimulating hormone (α-MSH)-stimulated melanin formation in intact B16 melanoma cells. PMID:26579376

Inhibition of tyrosinase activity and melanine pigmentation by 2-hydroxytyrosol.

PubMed

Uchida, Ryuji; Ishikawa, Seiko; Tomoda, Hiroshi

2014-04-01

2-Hydroxytyrosol (2-HT), originally reported as a synthetic compound, was isolated for the first time as a fungal metabolite. 2-HT was found to inhibit mushroom tyrosinase with an IC50 value of 13.0 µmol/L. Furthermore, 2-HT dose-dependently inhibited tyrosinase activity (IC50, 32.5 µmol/L) in the cell-free extract of B16 melanoma cells and α-melanocyte stimulating hormone (α-MSH)-stimulated melanin formation in intact B16 melanoma cells.

Simplified molecular input line entry system-based: QSAR modelling for MAP kinase-interacting protein kinase (MNK1).

PubMed

Begum, S; Achary, P Ganga Raju

2015-01-01

Quantitative structure-activity relationship (QSAR) models were built for the prediction of inhibition (pIC50, i.e. negative logarithm of the 50% effective concentration) of MAP kinase-interacting protein kinase (MNK1) by 43 potent inhibitors. The pIC50 values were modelled with five random splits, with the representations of the molecular structures by simplified molecular input line entry system (SMILES). QSAR model building was performed by the Monte Carlo optimisation using three methods: classic scheme; balance of correlations; and balance correlation with ideal slopes. The robustness of these models were checked by parameters as rm(2), r(*)m(2), [Formula: see text] and randomisation technique. The best QSAR model based on single optimal descriptors was applied to study in vitro structure-activity relationships of 6-(4-(2-(piperidin-1-yl) ethoxy) phenyl)-3-(pyridin-4-yl) pyrazolo [1,5-a] pyrimidine derivatives as a screening tool for the development of novel potent MNK1 inhibitors. The effects of alkyl group, -OH, -NO2, F, Cl, Br, I, etc. on the IC50 values towards the inhibition of MNK1 were also reported.

Monoclonal antibodies with group specificity toward sulfonamides: selection of hapten and antibody selectivity.

PubMed

Wang, Zhanhui; Beier, Ross C; Sheng, Yajie; Zhang, Suxia; Jiang, Wenxiao; Wang, Zhaopeng; Wang, Jin; Shen, Jianzhong

2013-05-01

Immunoassays based on the current available antibodies for large multi-sulfonamide screening programs have suffered from high selectivity for individual sulfonamides and a wide range of selectivities for different sulfonamides. In this study, five synthesized haptens, HS, BS, CS, SA10, and TS and two sulfonamides, SG and SMX were used as haptens, which may or may not contain a ring structure at the N1 position of the sulfonamides, were selected to evaluate the effectiveness for producing group-specific monoclonal antibodies (MAbs). Mice immunized with three different two-ring haptens were used for hybridoma production, which resulted in three unique MAbs recognizing 10, 13, and 15 sulfonamides showing 50 % inhibition (IC50) at concentrations below 100 ng mL(-1). MAb 4D11 derived from one novel immunizing hapten could recognize 12 sulfonamides with IC50 values ranging from 1.2 to 12.4 ng mL(-1), almost within 1 order of magnitude. These produced MAbs show lower IC50 values in addition to significantly improved group specificity compared with previously generated MAbs. This study clearly indicates that the careful selection of the immunizing hapten has an important effect on the specificity of the generated antibodies.

Tetrahydrobenzo[h][1,6]naphthyridine-6-chlorotacrine hybrids as a new family of anti-Alzheimer agents targeting β-amyloid, tau, and cholinesterase pathologies.

PubMed

Di Pietro, Ornella; Pérez-Areales, F Javier; Juárez-Jiménez, Jordi; Espargaró, Alba; Clos, M Victòria; Pérez, Belén; Lavilla, Rodolfo; Sabaté, Raimon; Luque, F Javier; Muñoz-Torrero, Diego

2014-09-12

Optimization of an essentially inactive 3,4-dihydro-2H-pyrano[3,2-c]quinoline carboxylic ester derivative as acetylcholinesterase (AChE) peripheral anionic site (PAS)-binding motif by double O → NH bioisosteric replacement, combined with molecular hybridization with the AChE catalytic anionic site (CAS) inhibitor 6-chlorotacrine and molecular dynamics-driven optimization of the length of the linker has resulted in the development of the trimethylene-linked 1,2,3,4-tetrahydrobenzo[h][1,6]naphthyridine-6-chlorotacrine hybrid 5a as a picomolar inhibitor of human AChE (hAChE). The tetra-, penta-, and octamethylene-linked homologues 5b-d have been also synthesized for comparison purposes, and found to retain the nanomolar hAChE inhibitory potency of the parent 6-chlorotacrine. Further biological profiling of hybrids 5a-d has shown that they are also potent inhibitors of human butyrylcholinesterase and moderately potent Aβ42 and tau anti-aggregating agents, with IC50 values in the submicromolar and low micromolar range, respectively. Also, in vitro studies using an artificial membrane model have predicted a good brain permeability for hybrids 5a-d, and hence, their ability to reach their targets in the central nervous system. The multitarget profile of the novel hybrids makes them promising leads for developing anti-Alzheimer drug candidates with more balanced biological activities. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Structural basis for drug and substrate specificity exhibited by FIV encoding a chimeric FIV/HIV protease

PubMed Central

Lin, Ying-Chuan; Perryman, Alexander L.; Olson, Arthur J.; Torbett, Bruce E.; Elder, John H.; Stout, C. David

2011-01-01

A chimeric feline immunodeficiency virus (FIV) protease (PR) has been engineered that supports infectivity but confers sensitivity to the human immunodeficiency virus (HIV) PR inhibitors darunavir (DRV) and lopinavir (LPV). The 6s-98S PR has five replacements mimicking homologous residues in HIV PR and a sixth which mutated from Pro to Ser during selection. Crystal structures of the 6s-98S FIV PR chimera with DRV and LPV bound have been determined at 1.7 and 1.8 Å resolution, respectively. The structures reveal the role of a flexible 90s loop and residue 98 in supporting Gag processing and infectivity and the roles of residue 37 in the active site and residues 55, 57 and 59 in the flap in conferring the ability to specifically recognize HIV PR drugs. Specifically, Ile37Val preserves tertiary structure but prevents steric clashes with DRV and LPV. Asn55Met and Val59Ile induce a distinct kink in the flap and a new hydrogen bond to DRV. Ile98Pro→Ser and Pro100Asn increase 90s loop flexibility, Gln99Val contributes hydrophobic contacts to DRV and LPV, and Pro100Asn forms compensatory hydrogen bonds. The chimeric PR exhibits a comparable number of hydrogen bonds, electrostatic interactions and hydrophobic contacts with DRV and LPV as in the corresponding HIV PR complexes, consistent with IC50 values in the nanomolar range. PMID:21636894

Study of the sensitivity of neonates to digoxin: contribution of erythrocyte /sup 86/Rb uptake test

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zannad, F.; Marchal, F.; Royer, R.J.

1981-01-01

In general, there is little agreement how digoxin should be used in newborn, and the results of studies in this field seem contradictory. This study attempts a quantitative assessment of the number and the sensitivity of cellular receptors for digoxin in the organism, by the in vitro measurement of erythrocyte /sup 86/Rb neonates compared with adults and old people. Red blood cells are first incubated with differing concentrations of digoxin, and then incubated with /sup 86/Rb. The initial level of /sup 86/Rb uptake (Rbi) is that observed in the absence of digoxin. The 50% index of captation (IC50) is themore » digoxin concentration in nanograms per ml at which /sup 86/Rb uptake is half Rbi. Three grups of patients were studied: Group I: 12 neonates, less that 5 days old; Group II: 11 adults (26 to 57 years old); Group III: 9 elderly people (71 to 82 years old). Rbi was significantly lower in neonates (Mean +/- SD: 25.8% +/- 3.5, P less than 0.001) and in the elderly (29.9% +/- 3.1) than in adults (36.8% +/- 4.6). IC50 was significantly lower in the elderly (12.1 mg/ml +/- 2.4) than in the adult patients (20.5 ng/ml +/- 5.5, P less than 0.001). In the newborns, values of IC50 were widely scattered (16.2 ng/ml +/- 7.2). The authors suggest that since Rbi reflects Na+, K+-ATPase activity, this activity is diminished in newborn and old people, and indicates that they have fewer cellular recaptors for digoxin than adults. In the elderly, the low IC50 would imply increased sensitivity to digoxin. In neonates, the wide range of values for IC50 suggests considerable individual variation in sensitivity to digoxin. The results aer consistent with the recently recomnended lower dosages of digoxin i neonates.« less

Design, synthesis, acetylcholinesterase inhibition and larvicidal activity of girgensohnine analogs on Aedes aegypti, vector of dengue fever.

PubMed

Carreño Otero, Aurora L; Vargas Méndez, Leonor Y; Duque L, Jonny E; Kouznetsov, Vladimir V

2014-05-06

Girgensohnine alkaloid was used as a natural model in the design and generation of new alkaloid-like α-aminonitrile series that was completed by the use of SSA-catalyzed Strecker reaction between commercial and inexpensive substituted benzaldehydes, piperidine (pyrrolidine, morpholine and N-methylpiperazine) and acetone cyanohydrin. Calculated ADMETox parameters of the designed analogs revealed their good pharmacokinetic profiles indicating lipophilic characteristics. In vitro AChE enzyme test showed that obtained α-aminonitriles could be considered as AChEIs with micromolar IC50 values ranging from 42.0 to 478.0 μM (10.3-124.0 μg/mL). Among this series, the best AChE inhibitor was the pyrrolidine α-aminonitrile 3 (IC50 = 42 μM), followed by the piperidine α-aminonitriles 2 and 6 (IC50 = 45 μM and IC50 = 51 μM, respectively), and the compound 7 (IC50 = 51 μM). In vivo insecticidal activity of more active AChEIs against Aedes aegypti larvae was also performed showing a good larvicidal activity at concentrations less than 140 ppm, highlighting products 2 and 7 that could serve as lead compounds to develop new potent and selective insecticides. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Evaluation of bisindole as potent β-glucuronidase inhibitors: synthesis and in silico based studies.

PubMed

Khan, Khalid Mohammed; Rahim, Fazal; Wadood, Abdul; Taha, Muhammad; Khan, Momin; Naureen, Shagufta; Ambreen, Nida; Hussain, Shafqat; Perveen, Shahnaz; Choudhary, Mohammad Iqbal

2014-04-01

Bisindole analogs 1-17 were synthesized and evaluated for their in vitro β-glucuronidase inhibitory potential. Out of seventeen compounds, the analog 1 (IC50=1.62±0.04 μM), 6 (IC50=1.86±0.05 μM), 10 (IC50=2.80±0.29 μM), 9 (IC50=3.10±0.28 μM), 14 (IC50=4.30±0.08 μM), 2 (IC50=18.40±0.09 μM), 19 (IC50=19.90±1.05 μM), 4 (IC50=20.90±0.62 μM), 7 (IC50=21.50±0.77 μM), and 3 (IC50=22.30±0.02 μM) showed superior β-glucuronidase inhibitory activity than the standard (d-saccharic acid 1,4-lactone, IC50=48.40±1.25 μM). In addition, molecular docking studies were performed to investigate the binding interactions of bisindole derivatives with the enzyme. This study has identified a new class of potent β-glucouronidase inhibitors. Copyright © 2014 Elsevier Ltd. All rights reserved.

Discovery of novel EGFR tyrosine kinase inhibitors by structure-based virtual screening.

PubMed

Li, Siyuan; Sun, Xianqiang; Zhao, Hongli; Tang, Yun; Lan, Minbo

2012-06-15

By using of structure-based virtual screening, 13 novel epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors were discovered from 197,116 compounds in the SPECS database here. Among them, 8 compounds significantly inhibited EGFR kinase activity with IC(50) values lower than 10 μM. 3-{[1-(3-Chloro-4-fluorophenyl)-3,5-dioxo-4-pyrazolidinylidene]methyl}phenyl 2-thiophenecarboxylate (13), particularly, was the most potent inhibitor possessing the IC(50) value of 3.5 μM. The docking studies also provide some useful information that the docking models of the 13 compounds are beneficial to find a new path for designing novel EGFR inhibitors. Copyright © 2012 Elsevier Ltd. All rights reserved.

Synthesis and biological evaluation of novel bis-aromatic amides as novel PTP1B inhibitors.

PubMed

Wang, Wen-Long; Huang, Chao; Gao, Li-Xin; Tang, Chun-Lan; Wang, Jun-Qing; Wu, Min-Chen; Sheng, Li; Chen, Hai-Jun; Nan, Fa-Jun; Li, Jing-Ya; Li, Jia; Feng, Bainian

2014-04-15

A series of bis-aromatic amides was designed, synthesized, and evaluated as a new class of inhibitors with IC50 values in the micromolar range against protein tyrosine phosphatase 1B (PTP1B). Among them, compound 15 displayed an IC50 value of 2.34±0.08 μM with 5-fold preference over TCPTP. More importantly, the treatment of CHO/HIR cells with compound 15 resulted in increased phosphorylation of insulin receptor (IR), which suggested extensive cellular activity of compound 15. These results provided novel lead compounds for the design of inhibitors of PTP1B as well as other PTPs. Copyright © 2014 Elsevier Ltd. All rights reserved.

8-9' linked neolignans with cytotoxicity from Alpinia conchigera.

PubMed

Xu, Jun-Ju; Zeng, Guang-Zhi; Yang, Sheng-Chao; Shen, Yong; Tan, Ning-Hua

2013-12-01

Five new 8-9' linked neolignans conchigeranals A-E (1-5), together with three known compounds galanganal (6), galanganols A (7) and B (8), were isolated from the whole plant of Alpinia conchigera. Their structures were established by spectroscopic analysis, including 2D-NMR spectroscopic techniques. Cytotoxicities of compounds 1-8 were tested against two cancer cell lines A549 and Hela. Results showed that 4, 5, 7 and 8 exhibited cytotoxicity against A549 with the IC50 values of 12.36, 9.72, 10.26, 13.05 μg/ml, respectively, and 1-8 against Hela with the IC50 values from 1.53 to 5.29 μg/ml. © 2013.

Compounds from the aerial parts of Piper bavinum and their anti-cholinesterase activity.

PubMed

Dung, Hoang Viet; Cuong, To Dao; Chinh, Nguyen Minh; Quyen, Do; Kim, Jeong Ah; Byeon, Jeong Su; Woo, Mi Hee; Choi, Jae Sui; Min, Byung Sun

2015-01-01

A new alkenylphenol, bavinol A (1), together with six known compounds (2-7) were isolated from the aerial parts of Piper bavinum (Piperaceae). The chemical structures of these compounds were determined by spectroscopic analyses including 2D NMR spectroscopy. The anti-Alzheimer effects of compounds 1-7 were evaluated from acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity assays. Bavinol A (1), ampelopsin (3), and violanthin (4) exhibited AChE inhibitory activities with IC50 values of 29.80, 59.47 and 79.80 μM. Compound 1 also showed the most potent BChE inhibitory activity with an IC50 value of 19.25 μM.

Anti-Proliferative Effect of Triterpenoidal Glycosides from the Roots of Anemone vitifolia through a Pro-Apoptotic Way.

PubMed

Bai, Changcai; Ye, Yunyun; Feng, Xiao; Bai, Ruifeng; Han, Lu; Zhou, Xiuping; Yang, Xinyao; Tu, Pengfei; Chai, Xingyun

2017-04-17

A cytotoxicity-guided phytochemical investigation of Anemone vitifolia roots led to the isolation of six oleanane saponins ( 1 - 6 ), which were reported from the species for the first time. Their structures were determined by comparing its MS and NMR data with those in literature. Compounds 1 - 4 showed significant inhibitory effects on the proliferation of hepatocellular carcinoma HepG2 cells with IC 50 values ranging from 2.0 to 8.5 μM, compared to positive control methotrexate with IC 50 value of 15.8 μM. Flow cytometry analysis revealed that compounds 1 - 4 exerted anti-proliferative effects through a pro-apoptotic way of hepatocellular carcinoma cells.

p-( sup 125 I)iodoclonidine is a partial agonist at the alpha 2-adrenergic receptor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gerhardt, M.A.; Wade, S.M.; Neubig, R.R.

1990-08-01

The binding properties of p-(125I)iodoclonidine (( 125I)PIC) to human platelet membranes and the functional characteristics of PIC are reported. (125I)PIC bound rapidly and reversibly to platelet membranes, with a first-order association rate constant (kon) at room temperature of 8.0 +/- 2.7 x 10(6) M-1 sec-1 and a dissociation rate constant (koff) of 2.0 +/- 0.8 x 10(-3) sec-1. Scatchard plots of specific (125I)PIC binding (0.1-5 nM) were linear, with a Kd of 1.2 +/- 0.1 nM. (125I)PIC bound to the same number of high affinity sites as the alpha 2-adrenergic receptor (alpha 2-AR) full agonist (3H) bromoxidine (UK14,304), which representedmore » approximately 40% of the sites bound by the antagonist (3H)yohimbine. Guanosine 5'-(beta, gamma-imido)triphosphate greatly reduced the amount of (125I)PIC bound (greater than 80%), without changing the Kd of the residual binding. In competition experiments, the alpha 2-AR-selective ligands yohimbine, bromoxidine, oxymetazoline, clonidine, p-aminoclonidine, (-)-epinephrine, and idazoxan all had Ki values in the low nanomolar range, whereas prazosin, propranolol, and serotonin yielded Ki values in the micromolar range. Epinephrine competition for (125I)PIC binding was stereoselective. Competition for (3H)bromoxidine binding by PIC gave a Ki of 1.0 nM (nH = 1.0), whereas competition for (3H)yohimbine could be resolved into high and low affinity components, with Ki values of 3.7 and 84 nM, respectively. PIC had minimal agonist activity in inhibiting adenylate cyclase in platelet membranes, but it potentiated platelet aggregation induced by ADP with an EC50 of 1.5 microM. PIC also inhibited epinephrine-induced aggregation, with an IC50 of 5.1 microM. Thus, PIC behaves as a partial agonist in a human platelet aggregation assay. (125I)PIC binds to the alpha 2B-AR in NG-10815 cell membranes with a Kd of 0.5 +/- 0.1 nM.« less

Antioxidant and free radical scavenging activity of Spondias pinnata

PubMed Central

Hazra, Bibhabasu; Biswas, Santanu; Mandal, Nripendranath

2008-01-01

Background Many diseases are associated with oxidative stress caused by free radicals. Current research is directed towards finding naturally-occurring antioxidants of plant origin. The aim of the present study was to evaluate the in vitro antioxidant activities of Spondias pinnata stem bark extract. Methods A 70% methanol extract of Spondias pinnata stem bark was studied in vitro for total antioxidant activity, for scavenging of hydroxyl radicals, superoxide anions, nitric oxide, hydrogen peroxide, peroxynitrite, singlet oxygen and hypochlorous acid, and for iron chelating capacity, reducing power, and phenolic and flavonoid contents. Results The extract showed total antioxidant activity with a trolox equivalent antioxidant concentration (TEAC) value of 0.78 ± 0.02. The IC50 values for scavenging of free radicals were 112.18 ± 3.27 μg/ml, 13.46 ± 0.66 μg/ml and 24.48 ± 2.31 μg/ml for hydroxyl, superoxide and nitric oxide, respectively. The IC50 for hydrogen peroxide scavenging was 44.74 ± 25.61 mg/ml. For the peroxynitrite, singlet oxygen and hypochlorous acid scavenging activities the IC50 values were 716.32 ± 32.25 μg/ml, 58.07 ± 5.36 μg/ml and 127.99 ± 6.26 μg/ml, respectively. The extract was found to be a potent iron chelator with IC50 = 66.54 ± 0.84 μg/ml. The reducing power was increased with increasing amounts of extract. The plant extract (100 mg) yielded 91.47 ± 0.004 mg/ml gallic acid-equivalent phenolic content and 350.5 ± 0.004 mg/ml quercetin-equivalent flavonoid content. Conclusion The present study provides evidence that a 70% methanol extract of Spondias pinnata stem bark is a potential source of natural antioxidants. PMID:19068130

Cytotoxic activity screening of Bangladeshi medicinal plant extracts.

PubMed

Akter, Raushanara; Uddin, Shaikh J; Grice, I Darren; Tiralongo, Evelin

2014-01-01

The cytotoxic activity of 23 crude methanol extracts from 19 Bangladeshi medicinal plants was investigated against healthy mouse fibroblasts (NIH3T3), healthy monkey kidney (VERO) and four human cancer cell lines (gastric, AGS; colon, HT-29; and breast, MCF-7 and MDA-MB-231) using MTT assay. High cytotoxicity across all cell lines tested was exhibited by Aegiceras corniculatum (fruit) and Hymenodictyon excelsum (bark) extracts (IC50 values ranging from 0.0005 to 0.9980 and 0.08 to 0.44 mg/mL, respectively). Fourteen extracts from 11 plant species, namely Clitoria ternatea (flower and leaf), Dillenia indica (leaf), Diospyros peregrina (leaf), Dipterocarpus turbinatus (bark and leaf), Ecbolium viride (leaf), Glinus oppositifolius (whole plant), Gnaphalium luteoalbum (leaf), Jasminum sambac (leaf), Lannea coromandelica (bark and leaf), Mussaenda glabrata (leaf) and Saraca asoca (leaf), were also significantly cytotoxic (IC50 < 1.0 mg/mL) against at least one of the cancer cell lines tested. More selectively, Avicennia alba (leaf), C. ternatea (flower and leaf), Caesalpinia pulcherrima (leaf), E. viride (leaf) and G. oppositifolius (whole plant) showed cytotoxicity only against both of the breast cancer cell lines (MCF-7 and MDA-MB-231). In contrast, C. ternatea (flower and leaf) exhibited high cytotoxic activity against MDA-MB-231 (IC50 values of 0.11 and 0.49 mg/mL, respectively), whereas E. viride and G. oppositifolius whole plant extracts exhibited high activity against MCF-7 cells (IC50 values of 0.06 and 0.15 mg/mL, respectively). The cytotoxic activity test results for 9 of the plant species correlate with their traditional use as anticancer agents, thus making them interesting sources for further drug development.

Synthesis and evaluation of new benzodioxole-based dithiocarbamate derivatives as potential anticancer agents and hCA-I and hCA-II inhibitors.

PubMed

Altıntop, Mehlika Dilek; Sever, Belgin; Akalın Çiftçi, Gülşen; Kucukoglu, Kaan; Özdemir, Ahmet; Soleimani, Seyedeh Sara; Nadaroglu, Hayrunnisa; Kaplancıklı, Zafer Asım

2017-01-05

In the current work, new benzodioxole-based dithiocarbamate derivatives were synthesized via the reaction of N-(1,3-benzodioxol-5-ylmethyl)-2-chloroacetamide with appropriate sodium salts of N,N-disubstituted dithiocarbamic acids. These derivatives were evaluated for their cytotoxic effects on A549 human lung adenocarcinoma and C6 rat glioma cell lines. N-(1,3-Benzodioxol-5-ylmethyl)-2-[4-(4-nitrophenyl)-1-piperazinylthiocarbamoylthio]acetamide (10) can be identified as the most promising anticancer agent against C6 cell line due to its notable inhibitory effect on C6 cells with an IC 50 value of 23.33 ± 7.63 μg/mL when compared with cisplatin (IC 50  = 19.00 ± 5.29 μg/mL). On the other hand, compound 10 did not show any significant cytotoxic activity against A549 cell line. The compounds were also tested for their in vitro inhibitory effects on hCA-I and hCA-II. Generally, the tested compounds were more effective on CAs than acetazolamide, the reference agent. Among these compounds, N-(1,3-benzodioxol-5-ylmethyl)-2-[(morpholinyl)thiocarbamoylthio]acetamide (3) and N-(1,3-benzodioxol-5-ylmethyl)-2-[(thiomorpholinyl)thiocarbamoylthio]acetamide (4) were found to be the most effective compounds on hCA-I with IC 50 values of 0.346 nM and 0.288 nM, and hCA-II with IC 50 values of 0.287 nM and 0.338 nM, respectively. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Cytotoxic, Antimitotic, and Antiproliferation Studies on Rasam: A South Indian Traditional Functional Food.

PubMed

Devarajan, Agilandeswari; Mohan Maruga Raja, M K

2017-10-01

Rasam is a traditional South Indian food, prepared using tamarind juice as a base, with a variety of spices. Rasam , with all its ingredients medicinally claimed for various ailments, is a functional food. Systematic consumption of traditional functional food provides an excellent preventive measure to ward off many diseases. To study rasam for cytotoxic, antimitotic, and antiproliferation potential beyond its culinary and nutritional effect. Brine shrimp lethality assay, onion root tip inhibition assay, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay in Calu-6, HeLa, MCF-7 cell lines for four stage-wise samples in the preparation of rasam (RS1, RS2, RS3, and RS4) were studied. RS4, the end product of rasam showed high lethality with an LC 50 value of 38.7 μL/mL. It showed maximum antimitotic activity in a dose-dependent manner compared to other samples with an IC 50 value of 189.86 μL/mL. RS4 also showed an IC 50 value of 350.22 and 410.15 μL/mL in MCF-7 and Calu-6 cell lines, respectively. From this study, we suggest that rasam is a classic example of traditional functional food and it can treat breast and lung cancer on chronic use. Rasam , a South Indian traditional functional food, showed high lethality (LC 50 = 38.7 mL/mL) against brine shrimps Rasam also showed potential antimitotic activity (IC 50 = 189.86 mL/mL) by inhibiting the onion root tips Rasam showed an IC 50 value of 350.22 and 410.15 mL/mL against MCF-7 and Calu-6 cell lines respectively Rasam , when consumed on daily dietary basis, can treat breast and lung cancer. Abbreviations used: SS 316: Stainless Steel 316 grade; MTT: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; DMEM: Dulbecco's modified Eagle medium; FBS: Fetal bovine serum media; TPVG: Trypsin phosphate versene glucose; EDTA: Ethylene diamine tetra acetic acid; PBS: Phosphate buffered saline; DMSO: Dimethyl sulfoxide.

Antiplasmodial activities of gold(I) complexes involving functionalized N-heterocyclic carbenes.

PubMed

Hemmert, Catherine; Ramadani, Arba Pramundita; Boselli, Luca; Fernández Álvarez, Álvaro; Paloque, Lucie; Augereau, Jean-Michel; Gornitzka, Heinz; Benoit-Vical, Françoise

2016-07-01

A series of twenty five molecules, including imidazolium salts functionalized by N-, O- or S-containing groups and their corresponding cationic, neutral or anionic gold(I) complexes were evaluated on Plasmodium falciparum in vitro and then on Vero cells to determine their selectivity. Among them, eight new compounds were synthesized and fully characterized by spectroscopic methods. The X-ray structures of three gold(I) complexes are presented. Except one complex (18), all the cationic gold(I) complexes show potent antiplasmodial activity with IC50 in the micro- and submicromolar range, correlated with their lipophilicity. Structure-activity relationships enable to evidence a lead-complex (21) displaying a good activity (IC50=210nM) close to the value obtained with chloroquine (IC50=514nM) and a weak cytotoxicity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Trypanocidal and Leishmanicidal Activities of Sesquiterpene Lactones from Ambrosia tenuifolia Sprengel (Asteraceae) ▿

PubMed Central

Sülsen, Valeria P.; Frank, Fernanda M.; Cazorla, Silvia I.; Anesini, Claudia A.; Malchiodi, Emilio L.; Freixa, Blanca; Vila, Roser; Muschietti, Liliana V.; Martino, Virginia S.

2008-01-01

Bioassay-guided fractionation of the organic extract of Ambrosia tenuifolia Sprengel (Asteraceae) led to the isolation of two bioactive sesquiterpene lactones with significant trypanocidal and leishmanicidal activities. By spectroscopic methods (1H- and 13C-nuclear magnetic resonance, distortionless enhancement by polarization transfer, correlated spectroscopy, heteronuclear multiple-quantum coherence, electron impact-mass spectrometry, and infrared spectroscopy), these compounds were identified as psilostachyin and peruvin. Both compounds showed a marked in vitro trypanocidal activity against Trypanosoma cruzi epimastigotes with 50% inhibitory concentration (IC50) values of less than 2 μg/ml. Psilostachyin exerted a significant in vitro activity against the trypomastigote forms of T. cruzi (IC50, 0.76 μg/ml) and was selected for in vivo testing. Psilostachyin-treated mice had a survival of 100% and lower parasitemia values than control mice. Both compounds were also tested on Leishmania sp. promastigotes: psilostachyin (IC50, 0.12 μg/ml) and peruvin (IC50, 0.39 μg/ml) exerted significant leishmanicidal activities. This is the first time that the trypanocidal and leishmanicidal activities of these compounds have been reported. The selectivity index (SI) was employed to evaluate the cytotoxic effect of lactones on T lymphocytes. Although the SIs of both compounds were high for T. cruzi epimastigotes, psilostachyin was more selective against trypomastigotes (SI, 33.8) while peruvin showed no specificity for this parasite. Both compounds presented high selectivity for Leishmania spp. The results shown herein suggest that psilostachyin and peruvin could be considered potential candidates for the development of new antiprotozoal agents against Chagas' disease and leishmaniasis. PMID:18443111

The pharmacological profile of CGP 28238, a novel highly potent anti-inflammatory compound.

PubMed

Wiesenberg-Boettcher, I; Schweizer, A; Green, J R; Mueller, K; Maerki, F; Pfeilschifter, J

1989-01-01

CGP 28238 (6-(2,4-difluorophenoxy)-5-methylsulfonylamino-1-indanone ) exhibits very potent anti-inflammatory activity in rat adjuvant arthritis (ED40 = 0.05 mg/kg, p.o.) and pronounced analgesic and antipyretic activity in acute models in mice and rats (ED50 2-5 mg/kg, p.o.), but has clear advantages over reference NSAIDs with respect to gastro-intestinal tolerability. Threshold doses for gastro-intestinal ulcerogenicity in rats after single and repeated (10x) doses were found to be 30 mg/kg, p.o., and prostaglandin (PGE2) production in rat gastric and ileal mucosa was only marginally inhibited (ED50 greater than 30 mg/kg, p.o.). On the other hand, PGE2 production in rat inflammatory exudate and thromboxane synthesis in rat blood were inhibited with ED50 values of less than or equal to 2 mg/kg, p.o. Although CGP28238 does not inhibit cyclooxygenase in bovine seminal vesicle microsomal preparations (IC50 greater than 10(-3) mol/l), potent inhibition of prostaglandin synthesis was shown in various in vitro systems using human and animal cells with IC50 values of less than 10(-6) mol/l. IL-1-stimulated bone resorption and PGE2 production in murine calvarial cultures were inhibited with IC50 values of 3 x 10(-7) and 2 x 10(-8) mol/l, respectively. 5-Lipoxygenase (murine macrophages), phospholipase A2 (human PMN) and phospholipase C (human platelets) were not inhibited. CGP 28238 may represent a novel highly potent anti-inflammatory compound with improved gastro-intestinal safety.

A Green Synthesis of Chalcones As an Antioxidant and Anticancer

NASA Astrophysics Data System (ADS)

Susanti VH, Elfi; Agustina Eko Setyowati, Widiastuti

2018-01-01

Three chalcones (4’-amino-4-methoxy chalcone, 4’-amino-3,4-dimethoxy chalcone and 4’-amino-3,4,5-trimethoxy chalcone) has been synthesized by a green chemistry approach using grinding technique. Antioxidant activity of the chalcones were assessed using 1,1-biphenyl-2-picrylhydrazyl (DPPH) radical scavenging method. Cytotoxicity of chalcones sythesized was evaluated using a tetrazolium (MTT) colorimetric assay against cervical cancer cell line, HeLa. The antioxidant activity test showed that 4’-amino-4-methoxy chalcone had a stronger activity than the 4’-amino-3,4-dimethoxy chalcone and 4’-amino-3,4,5-trimethoxy chalcone, respectively with IC50 58.85, 64.79 and 210.3 μg/mL. These results indicate that there is a relationship between the structure of chalcone with antioxidant activity, the more methoxy groups in the ring B of the chalcone, antioxidant activity is getting smaller. The chalcone synthesized showed cytotoxicity against HeLa cell line with IC50 value of 31.75, 36.65, 49.04 μg/mL, respectively. It was observed that the highest cytotoxic activity was found at 4’-amino-4-methoxy chalcone (IC50 31.75 μg/mL). Lower activity was showed by 4’-amino-3,4,5-trimethoxy chalcone with IC50 value of 49,04 μg/mL. There is a relationship cytotoxicity with chalcone structure, the more the number of methoxy groups in ring B chalcone, will decrease the activity of cytotoxicity.

Xanthatin and xanthinosin from the burs of Xanthium strumarium L. as potential anticancer agents.

PubMed

Ramírez-Erosa, Irving; Huang, Yaoge; Hickie, Robert A; Sutherland, Ronald G; Barl, Branka

2007-11-01

Xanthatin and xanthinosin, 2 sesquiterpene lactones isolated from the burs of Xanthiun strumarium L. (cocklebur), showed moderate to high in vitro cytotoxic activity in the human cancer cell lines WiDr ATCC (colon), MDA-MB-231 ATCC (breast), and NCI-417 (lung). Xanthatin and xanthinosin were purified as the result of a multi-screening bioassay-guided study of wild plant species of the family Asteraceae, collected from various sites in Saskatchewan, Canada. Seventy-five extracts at a single concentration of 100 microg/mL were evaluated for in vitro cytotoxicity to the human cancer cell lines used. The chloroform extract of Carduus nutans L. (nodding thistle) aerial parts (IC50, 9.3 microg/mL) and the hexane extract of Echinacea angustifolia DC. (narrow-leaved purple coneflower) root (IC50, 4.0 microg/mL) were moderately to highly cytotoxic to the lung cancer cell line. The chloroform extracts of X. strumarium L. burs and Tanacetum vulgare L. (tansy) aerial parts exhibited the highest cytotoxicity for all cell lines tested; their IC50 values, obtained from multidose testing, ranged from 0.1 to 6.2 microg/mL (X. strumarium) and from 2.4 to 9.1 microg/mL (T. vulgare). Further purification of the chloroform fraction of X. strumarium yielded xanthatin and xanthinosin in high yields. This is the first time that these compounds have been reported in the burs of X. strumarium. Their IC50 values are also reported herein.

Synthesis, Biological Evaluation and Molecular Docking Study of Hydrazone-Containing Pyridinium Salts as Cholinesterase Inhibitors.

PubMed

Parlar, Sulunay; Bayraktar, Gulsah; Tarikogullari, Ayse Hande; Alptüzün, Vildan; Erciyas, Ercin

2016-01-01

A series of pyridinium salts bearing alkylphenyl groups at 1 position and hydrazone structure at 4 position of the pyridinium ring were synthesized and evaluated for the inhibition of both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) enzymes. The cholinesterase (ChE) inhibitory activity studies were carried out by using the Ellman's colorimetric method. All compounds displayed considerable AChE and BuChE inhibitory activity and some of the compounds manifested remarkable anti-AChE activity compared to the reference compound, galantamine. Among the title compounds, the series including benzofuran aromatic ring exhibited the best inhibitory activity both on AChE and BuChE enzymes. Compound 3b, 4-[2-(1-(benzofuran-2-yl)ethylidene)hydrazinyl]-1-(3-phenylpropyl)pyridinium bromide, was the most active compound with IC50 value of 0.23 (0.24) µM against enantiomeric excess (ee)AChE (human (h)AChE) while compound 3a, 4-[2-(1-(benzofuran-2-yl)ethylidene)hydrazinyl]-1-phenethylpyridinium bromide, was the most active compound with IC50 value of 0.95 µM against BuChE. Moreover, 3a and b exhibited higher activity than the reference compound galantamine (eeAChE (hAChE) IC50 0.43 (0.52) µM; BuChE IC50 14.92 µM). Molecular docking studies were carried out on 3b having highest inhibitory activity against AChE.

Bioaccessibility and inhibitory effects on digestive enzymes of carnosic acid in sage and rosemary.

PubMed

Ercan, Pınar; El, Sedef Nehir

2018-04-28

In this study, the aim was to determine the bioaccessibilities of carnosic acid in sage and rosemary and in vitro inhibitory effects of these samples on lipid and starch digestive enzymes by evaluating the lipase, α-amylase and α-glucosidase enzyme inhibition activities. The content of carnosic acid in rosemary (18.72 ± 0.33 mg/g) was found to be higher than that content of that in sage (3.76 ± 0.13 mg/g) (p < 0.05). The carnosic acid bioaccessibilities were found as 45.10 ± 1.88% and 38.32 ± 0.21% in sage and rosemary, respectively. The tested sage and rosemary showed inhibitory activity against α-glucosidase (Concentration of inhibitor required to produce a 50% inhibition of the initial rate of reaction - IC 50 88.49 ± 2.35, 76.80 ± 1.68 μg/mL, respectively), α-amylase (IC 50 107.65 ± 12.64, 95.65 ± 2.73 μg/mL, respectively) and lipase (IC 50 6.20 ± 0.63, 4.31 ± 0.62 μg/mL, respectively). Furthermore, to the best of our knowledge, this is the first work that carnosic acid standard equivalent inhibition capacities (CAEIC 50 ) for these food samples were determined and these values were in agreement with the IC 50 values. These results show that sage and rosemary are potent inhibitors of lipase, α-amylase and α-glucosidase digestive enzymes. Copyright © 2018 Elsevier B.V. All rights reserved.

Assessment of antimalarial activity against Plasmodium falciparum and phytochemical screening of some Yemeni medicinal plants

PubMed Central

Alshawsh, Mohammed A.; Al-shamahy, Hassan A.; Alsllami, Salah F.; Lindequist, Ulrike

2009-01-01

Developing countries, where malaria is one of the most prevalent diseases, still rely on traditional medicine as a source for the treatment of this disease. In the present study, six selected plants (Acalypha fruticosa, Azadirachta indica, Cissus rotundifolia, Echium rauwalfii, Dendrosicyos socotrana and Boswellia elongata) commonly used in Yemen by traditional healers for the treatment of malaria as well as other diseases, were collected from different localities of Yemen, dried and extracted with methanol and water successfully. The antiplasmodial activity of the extracts was evaluated against fresh clinical isolates of Plasmodium falciparum. The selectivity parameters to evaluate the efficacy of these medicinal plants were measured by in vitro micro test (Mark III) according to World Health Organization (WHO) 1996 & WHO 2001 protocols of antimalarial drug tests. Among the investigated 12 extracts, three were found to have significant antiplasmodial activity with IC50 values less than 4 µg/ml, namely the water extracts of A. fruticosa, A. indica and D. socotrana. Six extracts showed moderate activity with IC50 values ranging from 10 to 30 µg/ml and three appeared to be inactive with IC50 values more than 30 µg/ml. In addition, preliminary phytochemical screening of the methanolic and aqueous extracts indicated the presence of saponins, tannins, flavonoids, terpenoids, polysaccharides and peptides. PMID:18955251

Tanzawaic acid derivatives from a marine isolate of Penicillium sp. (SF-6013) with anti-inflammatory and PTP1B inhibitory activities.

PubMed

Quang, Tran Hong; Ngan, Nguyen Thi Thanh; Ko, Wonmin; Kim, Dong-Cheol; Yoon, Chi-Su; Sohn, Jae Hak; Yim, Joung Han; Kim, Youn-Chul; Oh, Hyuncheol

2014-12-15

Chemical investigation of a marine-derived fungus Penicillium sp. SF-6013 resulted in the discovery of a new tanzawaic acid derivative, 2E,4Z-tanzawaic acid D (1), together with four known analogues, tanzawaic acids A (2) and D (3), a salt form of tanzawaic acid E (4), and tanzawaic acid B (5). Their structures were mainly determined by analysis of NMR and MS data, along with chemical methods. Preliminary screening for anti-inflammatory effects in lipopolysaccharide (LPS)-activated microglial BV-2 cells showed that compounds 1, 2, and 5 inhibited the production of nitric oxide (NO) with IC50 values of 37.8, 7.1, and 42.5 μM, respectively. Compound 2 also inhibited NO production in LPS-stimulated RAW264.7 murine macrophages with an IC50 value of 27.0 μM. Moreover, these inhibitory effects correlated with the suppressive effect of compound 2 on inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression in LPS-stimulated RAW264.7 and BV2 cells. In addition, compounds 2 and 5 significantly inhibited the activity of protein tyrosine phosphatase 1B (PTP1B) with the same IC50 value (8.2 μM). Copyright © 2014 Elsevier Ltd. All rights reserved.

Constituents of PG201 (Layla(®)), a multi-component phytopharmaceutical, with inhibitory activity on LPS-induced nitric oxide and prostaglandin E2 productions in macrophages.

PubMed

Kim, Hyun Ji; Kim, Hye Mi; Ryu, Byeol; Lee, Woo-Seok; Shin, Ji-Sun; Lee, Kyung-Tae; Jang, Dae Sik

2016-02-01

Fourteen compounds, coumarin (1), demethylsuberosin (2), xanthotoxin (3), psoralen (4), decursinol (5), decursin (6), decursinol angelate (7), chikusetsusaponin IVa (8), chikusetsusaponin IVa methyl ester (9), ethyl caffeate (10), syringaresinol (11), cnidilide (12), farnesol (13), and linoleic acid (14), were isolated from phytopharmaceutical PG201 (Layla(®)) by activity-guided fractionation utilizing inhibitory activity on nitric oxide (NO) production in vitro. The isolates 1-14 were evaluated for their inhibitory activity on LPS-induced NO and prostaglandin E2 (PGE2) productions in RAW 264.7 cells. All the compounds except 14 displayed suppressive effects on LPS-induced NO and PGE2 production with IC50 values ranging from 8 to 60 μM. Among these, compound 10 showed the most potent inhibitory effect on NO production from RAW 264.7 cells with an IC50 value of 8.25 μM. Compounds 2, 9, and 10 exhibited high inhibitory effects on PGE2 production with the IC50 values of 9.42, 7.51, and 6.49 μM, respectively. These findings suggest that compounds 2, 9, and 10 are the potential anti-inflammatory active constituents of PG201 and further study may be needed to explain their mechanism of action.

Understanding drugs in breast cancer through drug sensitivity screening.

PubMed

Uhr, Katharina; Prager-van der Smissen, Wendy J C; Heine, Anouk A J; Ozturk, Bahar; Smid, Marcel; Göhlmann, Hinrich W H; Jager, Agnes; Foekens, John A; Martens, John W M

2015-01-01

With substantial numbers of breast tumors showing or acquiring treatment resistance, it is of utmost importance to develop new agents for the treatment of the disease, to know their effectiveness against breast cancer and to understand their relationships with other drugs to best assign the right drug to the right patient. To achieve this goal drug screenings on breast cancer cell lines are a promising approach. In this study a large-scale drug screening of 37 compounds was performed on a panel of 42 breast cancer cell lines representing the main breast cancer subtypes. Clustering, correlation and pathway analyses were used for data analysis. We found that compounds with a related mechanism of action had correlated IC50 values and thus grouped together when the cell lines were hierarchically clustered based on IC50 values. In total we found six clusters of drugs of which five consisted of drugs with related mode of action and one cluster with two drugs not previously connected. In total, 25 correlated and four anti-correlated drug sensitivities were revealed of which only one drug, Sirolimus, showed significantly lower IC50 values in the luminal/ERBB2 breast cancer subtype. We found expected interactions but also discovered new relationships between drugs which might have implications for cancer treatment regimens.

Antioxidant potential of n-butanol fraction from extract of Jasminum mesnyi Hance leaves.

PubMed

Borar, Sakshi; Punia, Priyanka; Kalia, A N

2011-01-01

Methanolic extract of Jasminum mesnyi Hance leaves having antidiabetic activity was subjected to fractionation to obtain antioxidant and antihyperglycemic rich fraction. Different concentrations of ethyl acetate and n-butanol fractions were subjected to antioxidant assay by DPPH method, nitric oxide scavenging activity and reducing power assay. The fractions showed dose dependent free radical scavenging property in all the models. IC50 values for ethyl acetate and n-butanol fractions were 153.45 +/- 6.65 and 6.22 +/- 0.25 microg/ml, respectively, as compared to L-ascorbic acid and rutin (as standards; IC50 values 6.54 +/- 0.24 and 5.43 +/- 0.21 microg/ml, respectively) in DPPH model. In nitric oxide scavenging activity, IC50 values were 141.54 +/- 9.95 microg/ml, 35.12 +/- 1.58 microg/ml, 21.06 +/- 0.95 microg/ml and 29.93 +/- 0.32 microg/ml for ethyl acetate, n-butanol fractions, L-ascorbic acid and rutin, respectively. n-Butanol fraction showed a good reducing potential and better free radical scavenging activity as compared to ethyl acetate fraction. Potent antioxidant n-butanol fraction showed better oral glucose tolerance test (antihyperglycemic) at par with metformin (standard drug), n-Butanol fraction contained secoiridoid glycosides which might be responsible for both antioxidant and antihyperglycemic activity.

Inhibition of α-glucosidase activity by ethanolic extract of Melia azedarach L. leaves

NASA Astrophysics Data System (ADS)

Sulistiyani; Safithri, Mega; Puspita Sari, Yoana

2016-01-01

Development of α-glucosidase inhibitor derived from natural products is an opportunity for a more economic management of diabetes prevention. The objective of this study was to test the activity of α-glucosidase with or without potential inhibitor compounds. By in vitro method, α-glucosidase hydrolizes p-nitrophenyl-α-D-glucopiranoside to glucose and the yellow of p-nitrophenol which can be determined with spectrophotometry at 400 nm. The ability of ethanolic leaf extract of Melia azedarach L. as a-glucosidase inhibitor was compared with that of commercial acarbose (Glucobay®). Acarbose showed strong inhibitory activity against a-glucosidase with IC50 values of 2.154 µg/mL. The crude ethanolic leaf extract of M. azedarach, however, showed less inhibitory activity with IC50 value of 3, 444.114 µg/mL. Total phenolics of M. azedarach leaves EtOH extract showed 17.94 µg GAE/mg extract and flavonoids total compound of 9.55 µg QE/mg extract. Based on the published wide range of IC50 values of extracts reported as a-glucosidase inhibitor which were between 10, 000 ppm-0.66 ppm, our result suggests that extract of M.azedarach leaves is potential candidate for development of anti-hyperglycemic formulation.

Chemical profile, radical scavenging and cytotoxic activity of yellow gentian leaves (Genitaneae luteaefolium) grown in northern regions of Montenegro.

PubMed

Balijagić, Jasmina; Janković, Teodora; Zdunić, Gordana; Bosković, Jelena; Savikin, Katarina; Godevac, Dejan; Stanojković, Tatjana; Jovancević, Miodrag; Menković, Nebojsa

2012-11-01

LC-ESI-MS and HPLC were used for the identification of the constituents from G. lutea leaves collected at different localities, as well as for quantification of the main compounds. Seven secoiridoids, five C-glucoflavones and three xanthones, were identified. Swertiamarin derivatives, namely eustomorusside (2), eustomoside (3) and septemfidoside (5), were detected in G. lutea for the first time. Concentrations of five constituents (swertiamarin, gentiopicrin, isovitexin, mangiferin and isogentisin) were determined. The relationship between concentrations of y-pyrones and altitude was observed with statistically significant correlation (r = 0.94). The extracts were also evaluated for their content of total phenolics, and antiradical and cytotoxic activities. The total phenolics content ranged from 7.7 to 12.7 mg GAE/g, and the IC50 values for DPPH radical scavenging activity varied between 0.45 to 2.02 mg/mL. The leaf extract exhibited moderate cytotoxic effects toward HeLa cells with an IC50 value of 41.1 microg/mL, while gentiopicrin, mangiferin and isogentisin exerted strong activity against HeLa cells, with IC50 values ranging from 5.7 to 8.8 microg/mL. The results confirm the traditional usage of G. lutea leaves and also suggest their possible utilization as hepatoprotective, hypoglycemic and anti-inflammatory agents.

Flavonoids from Machilus japonica Stems and Their Inhibitory Effects on LDL Oxidation

PubMed Central

Joo, Se-Jin; Park, Hee-Jung; Park, Ji-Hae; Cho, Jin-Gyeong; Kang, Ji-Hyun; Jeong, Tae-Sook; Kang, Hee Cheol; Lee, Dae-Young; Kim, Hack-Soo; Byun, Sang-Yo; Baek, Nam-In

2014-01-01

Stems of Machilus japonica were extracted with 80% aqueous methanol (MeOH) and the concentrated extract was successively extracted with ethyl acetate (EtOAc), normal butanol (n-BuOH), and water. Six flavonoids were isolated from the EtOAc fraction: (+)-taxifolin, afzelin, (−)-epicatechin, 5,3'-di-O-methyl-(−)-epicatechin, 5,7,3'-tri-O-methyl-(−)-epicatechin, and 5,7-di-O-methyl-3',4'-methylenedioxyflavan-3-ol. The chemical structures were identified using spectroscopic data including NMR, mass spectrometry and infrared spectroscopy. This is the first report of isolation of these six compounds from M. japonica. The compounds were evaluated for their diphenyl picryl hydrazinyl scavenging activity and inhibitory effects on low-density lipoprotein oxidation. Compounds 1 and 3–6 exhibited DPPH antioxidant activity equivalent with that of ascorbic acid, with half maximal inhibitory concentration (IC50) values of 0.16, 0.21, 0.17, 0.15 and 0.07 mM, respectively. The activity of compound 1 was similar to the positive control butylated hydroxytoluene, which had an IC50 value of 1.9 µM, while compounds 3 and 5 showed little activity. Compounds 1, 3, and 5 exhibited LDL antioxidant activity with IC50 values of 2.8, 7.1, and 4.6 µM, respectively. PMID:25229822

Combination of Oxaliplatin and Vit.E-TPGS in Lipid Nanosystem for Enhanced Therapeutic Efficacy in Colon Cancers.

PubMed

Wang, Yanlei; Zhang, Xiang; Zhang, Wenqiang; Dong, Hao; Zhang, Wenjie; Mao, Jiajia; Dai, Yong

2018-01-08

The main aim of present study was to prepare the oxaliplatin (OXL)-loaded D-α-Tocopherol polyethylene glycol 1000 succinate (TPGS)-based lipid nanoparticles to enhance the anticancer effect in colon cancer cells. The nanoparticles were nanosized and spherical shaped and exhibited controlled release kinetics. Flow cytometer and confocal laser scanning microscopy (CLSM) showed a remarkable uptake of nanoparticles in cancer cells in a time-dependent manner. The presence of TPGS remarkably increased the anticancer effect of OXL in HT-29 colon cancer cells. The IC50 value of free OXL was 4.25 μg/ml whereas IC50 value of OXL-loaded TPGS-based lipid nanoparticles (OXL/TLNP) was 1.12 μg/ml. The 3-fold lower IC50 value of OXL/TLNP indicates the superior anticancer effect of nanoparticle-based OXL. Consistently, OXL/TLNP induced a remarkable apoptosis of cancer cells. Approximately, ~52% of cells were in early apoptosis phase and ~13% of cells were in late apoptosis phase indicating the potent anticancer effect of the formulations. The findings from this study provide novel insights into the use of TPGS and lipid nanoparticle together for the better antitumor effect in colon cancers. Future studies will involve the detailed in vitro and in vivo studies on clinically relevant animals.

Antiviral activity of four types of bioflavonoid against dengue virus type-2

PubMed Central

2011-01-01

Background Dengue is a major mosquito-borne disease currently with no effective antiviral or vaccine available. Effort to find antivirals for it has focused on bioflavonoids, a plant-derived polyphenolic compounds with many potential health benefits. In the present study, antiviral activity of four types of bioflavonoid against dengue virus type -2 (DENV-2) in Vero cell was evaluated. Anti-dengue activity of these compounds was determined at different stages of DENV-2 infection and replication cycle. DENV replication was measured by Foci Forming Unit Reduction Assay (FFURA) and quantitative RT-PCR. Selectivity Index value (SI) was determined as the ratio of cytotoxic concentration 50 (CC50) to inhibitory concentration 50 (IC50) for each compound. Results The half maximal inhibitory concentration (IC50) of quercetin against dengue virus was 35.7 μg mL-1 when it was used after virus adsorption to the cells. The IC50 decreased to 28.9 μg mL-1 when the cells were treated continuously for 5 h before virus infection and up to 4 days post-infection. The SI values for quercetin were 7.07 and 8.74 μg mL-1, respectively, the highest compared to all bioflavonoids studied. Naringin only exhibited anti-adsorption effects against DENV-2 with IC50 = 168.2 μg mL-1 and its related SI was 1.3. Daidzein showed a weak anti-dengue activity with IC50 = 142.6 μg mL-1 when the DENV-2 infected cells were treated after virus adsorption. The SI value for this compound was 1.03. Hesperetin did not exhibit any antiviral activity against DENV-2. The findings obtained from Foci Forming Unit Reduction Assay (FFURA) were corroborated by findings of the qRT-PCR assays. Quercetin and daidzein (50 μg mL-1) reduced DENV-2 RNA levels by 67% and 25%, respectively. There was no significant inhibition of DENV-2 RNA levels with naringin and hesperetin. Conclusion Results from the study suggest that only quercetin demonstrated significant anti-DENV-2 inhibitory activities. Other bioflavonoids, including daidzein, naringin and hesperetin showed minimal to no significant inhibition of DENV-2 virus replication. These findings, together with those previously reported suggest that select group of bioflavonoids including quercetin and fisetin, exhibited significant inhibitory activities against dengue virus. This group of flavonoids, flavonol, could be investigated further to discover the common mechanisms of inhibition of dengue virus replication. PMID:22201648

Antiviral activity of four types of bioflavonoid against dengue virus type-2.

PubMed

Zandi, Keivan; Teoh, Boon-Teong; Sam, Sing-Sin; Wong, Pooi-Fong; Mustafa, Mohd Rais; Abubakar, Sazaly

2011-12-28

Dengue is a major mosquito-borne disease currently with no effective antiviral or vaccine available. Effort to find antivirals for it has focused on bioflavonoids, a plant-derived polyphenolic compounds with many potential health benefits. In the present study, antiviral activity of four types of bioflavonoid against dengue virus type -2 (DENV-2) in Vero cell was evaluated. Anti-dengue activity of these compounds was determined at different stages of DENV-2 infection and replication cycle. DENV replication was measured by Foci Forming Unit Reduction Assay (FFURA) and quantitative RT-PCR. Selectivity Index value (SI) was determined as the ratio of cytotoxic concentration 50 (CC50) to inhibitory concentration 50 (IC50) for each compound. The half maximal inhibitory concentration (IC50) of quercetin against dengue virus was 35.7 μg mL-1 when it was used after virus adsorption to the cells. The IC50 decreased to 28.9 μg mL-1 when the cells were treated continuously for 5 h before virus infection and up to 4 days post-infection. The SI values for quercetin were 7.07 and 8.74 μg mL-1, respectively, the highest compared to all bioflavonoids studied. Naringin only exhibited anti-adsorption effects against DENV-2 with IC50 = 168.2 μg mL-1 and its related SI was 1.3. Daidzein showed a weak anti-dengue activity with IC50 = 142.6 μg mL-1 when the DENV-2 infected cells were treated after virus adsorption. The SI value for this compound was 1.03. Hesperetin did not exhibit any antiviral activity against DENV-2. The findings obtained from Foci Forming Unit Reduction Assay (FFURA) were corroborated by findings of the qRT-PCR assays. Quercetin and daidzein (50 μg mL-1) reduced DENV-2 RNA levels by 67% and 25%, respectively. There was no significant inhibition of DENV-2 RNA levels with naringin and hesperetin. Results from the study suggest that only quercetin demonstrated significant anti-DENV-2 inhibitory activities. Other bioflavonoids, including daidzein, naringin and hesperetin showed minimal to no significant inhibition of DENV-2 virus replication. These findings, together with those previously reported suggest that select group of bioflavonoids including quercetin and fisetin, exhibited significant inhibitory activities against dengue virus. This group of flavonoids, flavonol, could be investigated further to discover the common mechanisms of inhibition of dengue virus replication.

Design and synthesis of some new carboxamide and propanamide derivatives bearing phenylpyridazine as a core ring and the investigation of their inhibitory potential on in-vitro acetylcholinesterase and butyrylcholinesterase.

PubMed

Kilic, Burcu; Gulcan, Hayrettin O; Aksakal, Fatma; Ercetin, Tugba; Oruklu, Nihan; Umit Bagriacik, E; Dogruer, Deniz S

2018-05-08

A series of new carboxamide and propanamide derivatives bearing phenylpyridazine as a core ring were designed, synthesized and evaluated for their ability to inhibit both cholinesterase enzymes. In addition, a series of carboxamide and propanamide derivatives bearing biphenyl instead of phenylpyridazine were also synthesized to examine the inhibitory effect of pyridazine moiety on both cholinesterase enzymes. The inhibitory activity results revealed that compounds 5b, 5f, 5h, 5j, 5l pyridazine-3-carboxamide derivative, exhibited selective acetylcholinesterase (AChE) inhibition with IC 50 values ranging from 0.11 to 2.69 µM. Among them, compound 5h was the most active one (IC 50  = 0.11 µM) without cytotoxic effect at its effective concentration against AChE. Additionally, pyridazine-3-carboxamide derivative 5d (IC 50 for AChE = 0.16 µM and IC 50 for BChE = 9.80 µM) and biphenyl-4-carboxamide derivative 6d (IC 50 for AChE = 0.59 µM and IC 50 for BChE = 1.48 µM) displayed dual cholinesterase inhibitory activity. Besides, active compounds were also tested for their ability to inhibit Aβ aggregation. Theoretical physicochemical properties of the compounds were calculated by using Molinspiration Program as well. The Lineweaver-Burk plot and docking study showed that compound 5 h targeted both the catalytic active site (CAS) and the peripheral anionic site (PAS) of AChE. Copyright © 2018 Elsevier Inc. All rights reserved.

Design, synthesis, and biological evaluation of 2-substituted-2,3,4,9-tetrahydrospiro-β-carboline-3-carboxylic acid derivatives as first-in-class mast cell stabilizers.

PubMed

Singh, Jatinder; Shah, Ramanpreet; Singh, Dhandeep; Jaggi, Amteshwar S; Singh, Nirmal

2018-05-01

Mast cell degranulation plays a momentous role in myriad diseases like asthma, eczema, allergic rhinitis, and conjunctivitis as well as anaphylactic shock; hence, there is an unmet need for developing new mast cells stabilizers. The reported mast cell stabilizers have a heterocyclic moiety and an acidic group. Furthermore, the role of tryptophan in suppression of mast cell activation is established. Hence, we prepared constrained analogs of tryptophan, which are derivatives of 2,3,4,9-tetrahydrospiro-β-carboline-3-carboxylic acid, and evaluated them for ex vivo inhibition of compound 48/80-induced mast degranulation activity. By comparing IC 50 (μM) values with that of the standard drug sodium cromoglycate (IC 50  = 0.489 ± 0.003 μM), compounds with bulky groups like heptyl (compound 9; IC 50  = 0.389 ± 0.015 μM) and octyl (compound 10; IC 50  = 0.354 ± 0.023 μM) were found to be of similar potency as sodium cromoglycate. Furthermore, the polar group-containing compounds like the chloropropyl (compound 16; IC 50  = 0.382 ± 0.083 μM) and benzoyl derivative (compound 14; IC 50  = 00.469 ± 0.032 μM) were also found to be of similar potency as sodium cromoglycate. This is a seminal study of spiro-β-carboline mast cell stabilization having a wider scope in mast cell research; yet, the mechanism of action remains elusive. © 2018 Deutsche Pharmazeutische Gesellschaft.

Constituents of the anti–asthma herbal formula ASHMI™ synergistically inhibit IL–4 and IL–5 secretion by murine Th2 memory cells, and eotaxin by human lung fibroblasts in vitro

PubMed Central

Jayaprakasam, Bolleddula; Yang, Nan; Wen, Ming-Chun; Wang, Rong; Goldfarb, Joseph; Sampson, Hugh; Li, Xiu-Min

2015-01-01

OBJECTIVE Anti-asthma herbal medicine intervention (ASHMI™), a combination of three traditional Chinese medicinal herbs developed in our laboratory, has demonstrated efficacy in both mouse models of allergic asthma, and a double-blind placebo-controlled clinical trial in patients with asthma. This study was designed to determine if the anti-inflammatory effects of individual herbal constituents of ASHMI™ exhibited synergy. METHODS Effects of ASHMI and its components aqueous extracts of Lingzhi (Ganoderma lucidum), Kushen (Sophora flavescens) and Gancao (Glycyrrhiza uralensis), on Th2 cytokine secretion by murine memory Th2 cells (D10.G4.1) and eotaxin-1 secretion by human lung fibroblast (HLF-1) cells were determined by measuring levels in culture supernatants by enzyme-linked immunosorbent assay. Potential synergistic effects were determined by computing interaction indices from concentration-effect curve parameters. RESULTS Individual Lingzhi, Kushen and Gancao extracts and ASHMI (the combination of individual extracts) inhibited production of interleukin (IL)-4 and IL-5 by murine memory Th2 cells and eotaxin-1 production by HLF-1 cells. The mean 25%-inhibitory-concentration (IC25) values (mg/mL) for ASHMI, Lingzhi, Kushen and Gancao for IL-4 production were 30.9, 79.4, 123, and 64.6, respectively; for IL-5 production were 30.2, 263, 123.2 and 100, respectively; for eotaxin-1 were 13.2, 16.2, 30.2, and 25.1, respectively. The IC50 values (mg/mL) for ASHMI, Lingzhi, Kushen and Gancao for IL-4 production were 158.5, 239.9, 446.7, and 281.8, respectively; for eotaxin-1 were 38.1, 33.1, 100, and 158.5, respectively. The interaction indices of ASHMI constituents at IC25 were 0.35 for IL-4, 0.21 for IL-5 and 0.59 for eotaxin-1. The interaction indices at IC50 values were 0.50 for IL-4 and 0.62 for eotaxin-1 inhibition. Inhibition of IL-5 did not reach IC50 values. All interaction indices were below 1 which indicated synergy. CONCLUSION By comparing the interaction index values, we find that constituents in ASHMI™ synergistically inhibited eotaxin-1 production as well as Th2 cytokine production. PMID:23743163

Drug repurposing: In-vitro anti-glycation properties of 18 common drugs

PubMed Central

Rasheed, Saima; Sánchez, Sara S.; Yousuf, Sammer; Honoré, Stella M.; Choudhary, M. Iqbal

2018-01-01

Drug repositioning or repurposing, i.e. identifying new indications for existing drugs, has gained increasing attention in the recent years. This approach enables the scientists to discover “new targets” for known drugs in a cost and time efficient manner. Glycation, the non-enzymatic reaction of sugars with proteins or nucleic acids to form early glycation (Amadori or fructosamine) products, is a key molecular basis of diabetic complications. Inhibiting the process of non-enzymatic protein glycation is one of the key strategies to prevent glycation-mediated diabetic complications. The present study focuses on the anti-glycation activity of 18 drugs, commonly used for the treatment of gastrointestinal, central nervous system, inflammatory diseases, bacterial infections, and gout. This study was carried out by using two in-vitro protein anti-glycation assay models. Results revealed that nimesulide (3), a non-steroidal anti-inflammatory drug, possesses a good anti-glycation activity in in-vitro BSA-MG and BSA-glucose glycation models with IC50 values of 330.56 ± 2.90, and 145.46 ± 16.35 μM, respectively. Phloroglucinol dihydrate (11), a drug used for the treatment of gastrointestinal diseases, showed a weak activity in BSA-MG glycation model (IC50 = 654.89 ± 2.50 μM), while it showed a good activity in BSA-glucose assay (IC50 = 148.23 ± 0.15 μM). Trimethylphloroglucinol (9), a drug used for the treatment of pain related to functional disorders of the digestive and biliary tracts, also showed a good antiglycation activity in BSA-MG model (IC50 = 321.15 ± 1.26 μM), while it was found to be inactive in in-vitro BSA-glucose assay (IC50 = 12.95% inhibition). These activities of drugs were compared with the anti-glycation activity of the standard, rutin (IC50 = 294.5 ± 1.50 μM in BSA-MG glycation model, and IC50 = 86.94 ± 0.24 μM in BSA- glucose model). Rest of the drugs exhibited a relatively weak antiglycation activity. This study identifies nimesulide (3), and phloroglucinol dihydrate (11) as new inhibitors of in-vitro protein glycation for further investigations as potential anti-diabetic agents. PMID:29300762

In vitro and in vivo anti-plasmodial activity of essential oils, including hinokitiol.

PubMed

Fujisaki, Ryuichi; Kamei, Kiyoko; Yamamura, Mariko; Nishiya, Hajime; Inouye, Shigeharu; Takahashi, Miki; Abe, Shigeru

2012-03-01

Abstract. The anti-plasmodial activity of 47 essential oils and 10 of their constituents were screened for in vitro activity against Plasmodium falciparum. Five of these essential oils (sandalwood, caraway, monarda, nutmeg, and Thujopsis dolabrata var. hondai) and 2 constituents (thymoquinone and hinokitiol) were found to be active against P. falciparum in vitro, with 50% inhibitory concentration (IC50) values equal to or less than 1.0 microg/ml. Furthermore, in vivo analysis using a rodent model confirmed the anti-plasmodial potential of subcutaneously administered sandalwood oil, and percutaneously administered hinokitiol and caraway oil against rodent P. berghei. Notably, these oils showed no efficacy when administered orally, intraperitoneally or intravenously. Caraway oil and hinokitiol dissolved in carrier oil, applied to the skin of hairless mice caused high levels in the blood, with concentrations exceeding their IC50 values.

Bisindolylmethane thiosemicarbazides as potential inhibitors of urease: Synthesis and molecular modeling studies.

PubMed

Taha, Muhammad; Ullah, Hayat; Al Muqarrabun, Laode Muhammad Ramadhan; Khan, Muhammad Naseem; Rahim, Fazal; Ahmat, Norizan; Javid, Muhammad Tariq; Ali, Muhammad; Khan, Khalid Mohammed

2018-01-01

Bisindolylmethane thiosemicarbazides 1-18 were synthesized, characterized by 1 H NMR and ESI MS and evaluated for urease inhibitory potential. All analogs showed outstanding urease inhibitory potentials with IC 50 values ranging between 0.14 ± 0.01 to 18.50 ± 0.90 μM when compared with the standard inhibitor thiourea having IC 50 value 21.25 ± 0.90 μM. Among the series, analog 9 (0.14 ± 0.01 μM) with di-chloro substitution on phenyl ring was identified as the most potent inhibitor of urease. The structure activity relationship has been also established on the basis of binding interactions of the active analogs. These binding interactions were identified by molecular docking studies. Copyright © 2017 Elsevier Ltd. All rights reserved.

Design, synthesis, and molecular hybrids of caudatin and cinnamic acids as novel anti-hepatitis B virus agents.

PubMed

Wang, Li-Jun; Geng, Chang-An; Ma, Yun-Bao; Luo, Jie; Huang, Xiao-Yan; Chen, Hao; Zhou, Ning-Jia; Zhang, Xue-Mei; Chen, Ji-Jun

2012-08-01

Forty-six conjugated derivatives of caudatin with substituted cinnamic acids were synthesized, and their anti-hepatitis B virus (HBV) activity was evaluated in HepG 2.2.15 cells. Most of the derivatives exhibited potent anti-HBV activity, especially inhibiting the HBV DNA replication with the IC(50) values from 2.44 to 22.89 μΜ. Compound 18 showed significant activity against the secretion of HBsAg, HBeAg, and HBV DNA replication with IC(50) values of 5.52, 5.52, 2.44 μΜ, respectively, and had good safety (LD(50) > 1250 mg/kg) according to the acute toxicity study. Preliminary mechanism investigation suggested that compound 18 exerted antivirus effects via interfering HBV X promoter and enhancer I to influence HBV transcriptions. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Trisubstituted barbiturates and thiobarbiturates: Synthesis and biological evaluation as xanthine oxidase inhibitors, antioxidants, antibacterial and anti-proliferative agents.

PubMed

Figueiredo, Joana; Serrano, João L; Cavalheiro, Eunice; Keurulainen, Leena; Yli-Kauhaluoma, Jari; Moreira, Vânia M; Ferreira, Susana; Domingues, Fernanda C; Silvestre, Samuel; Almeida, Paulo

2018-01-01

Barbituric and thiobarbituric acid derivatives have become progressively attractive to medicinal chemists due to their wide range of biological activities. Herein, different series of 1,3,5-trisubstituted barbiturates and thiobarbiturates were prepared in moderate to excellent yields and their activity as xanthine oxidase inhibitors, antioxidants, antibacterial agents and as anti-proliferative compounds was evaluated in vitro. Interesting bioactive barbiturates were found namely, 1,3-dimethyl-5-[1-(2-phenylhydrazinyl)ethylidene]pyrimidine-2,4,6(1H,3H,5H)-trione (6c) and 1,3-dimethyl-5-[1-[2-(4-nitrophenyl)hydrazinyl]ethylidene]pyrimidine-2,4,6(1H,3H,5H)-trione (6e), which showed concomitant xanthine oxidase inhibitory effect (IC 50 values of 24.3 and 27.9 μM, respectively), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity (IC 50 values of 18.8 and 23.8 μM, respectively). In addition, 5-[1-(2-phenylhydrazinyl)ethylidene]pyrimidine-2,4,6(1H,3H,5H)-trione (6d) also revealed DPPH radical scavenger effect, with an IC 50 value of 20.4 μM. Moreover, relevant cytotoxicity against MCF-7 cells (IC 50  = 13.3 μM) was observed with 5-[[(2-chloro-4-nitrophenyl)amino]methylene]-2-thioxodihydropyrimidine-4,6(1H,5H)-dione (7d). Finally, different 5-hydrazinylethylidenepyrimidines revealed antibacterial activity against Acinetobacter baumannii (MIC values between 12.5 and 25.0 μM) which paves the way for developing new treatments for infections caused by this Gram-negative coccobacillus bacterium, known to be an opportunistic pathogen in humans with high relevance in multidrug-resistant nosocomial infections. The most promising bioactive barbiturates were studied in silico with emphasis on compliance with the Lipinski's rule of five as well as several pharmacokinetics and toxicity parameters. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

New hydrazonoindolin-2-ones: Synthesis, exploration of the possible anti-proliferative mechanism of action and encapsulation into PLGA microspheres.

PubMed

Attia, Mohamed I; Eldehna, Wagdy M; Afifi, Samar A; Keeton, Adam B; Piazza, Gary A; Abdel-Aziz, Hatem A

2017-01-01

The synthesis and molecular characterization of new isatin-based hydrazonoindolin-2-ones 4a-o and 7a-e are reported. The in vitro anti-proliferative potential of the synthesized compounds 4a-o and 7a-e was examined against HT-29 (colon), ZR-75 (breast) and A549 (lung) human cancer cell lines. Compounds 7b, 7d and 7e were the most active congeners against the tested human cancer cell lines with average IC50 values of 4.77, 3.39 and 2.37 μM, respectively, as compared with the reference isatin-based drug, sunitinib, which exhibited an average IC50 value of 8.11 μM. Compound 7e was selected for further pharmacological evaluation in order to gain insight into its possible mechanism of action. It increased caspase 3/7 activity by 2.4- and 1.85-fold between 4 and 8 h of treatment, respectively, at 10 μM and it caused a decrease in the percentage of cells in the G1 phase of the cell cycle with a corresponding increase in the S-phase. In addition, compound 7e increased phosphorylated tyrosine (p-Tyr) levels nearly two-fold with an apparent IC50 value of 3.8 μM. The 7e-loaded PLGA microspheres were prepared using a modified emulsion-solvent diffusion method. The average encapsulation efficiency of the 7e-loaded PLGA microspheres was 85% ± 1.3. While, the in vitro release profile of the 7e-loaded microspheres was characterized by slow and continuous release of compound 7e during 21 days and the release curve was fitted to zero order kinetics. Incorporation of 7e into PLGA microspheres improved its in vitro anti-proliferative activity toward the human cancer cell line A549 after 120 h incubation period with an IC50 value less than 0.8 μM.

Low level tumor necrosis factor-alpha protects cardiomyocytes against high level tumor necrosis factor-alpha: brief insight into a beneficial paradox.

PubMed

Cacciapaglia, Fabio; Salvatorelli, Emanuela; Minotti, Giorgio; Afeltra, Antonella; Menna, Pierantonio

2014-12-01

Whether tumor necrosis factor-alpha (TNFα) caused beneficial or detrimental cardiovascular effects remains poorly defined. Anti-TNFα agents improved cardiac end points in chronic rheumatic diseases characterized by progressive deterioration of cardiac function. In contrast, anti-TNFα agents did not always improve but actually worsened cardiac function in non-rheumatic patients with heart failure (HF), in spite of that HF usually accompanies with high circulating levels of TNFα. To shed light on these mixed findings, we characterized the effects of TNFα in H9c2 cardiomyocytes. Cells were incubated for 24 h with increasing concentrations of TNFα, hydrogen peroxide, aminotriazole, or etoposide. Posttreatment cell viability was assessed by antimycin A-inhibitable reduction of 3-(4,dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, and the IC50 value of each test compound was defined. H9c2 cells were also preconditioned with a low non-toxic concentration of TNFα and then re-challenged with increasing concentrations of TNFα and other stressor agents. In re-challenge experiments, all of the IC50 values increased significantly, with the IC50 value of TNFα increasing approximately 16-fold. TNFα preconditioning increased cardiomyocytes shedding of the external portion of transmembrane type 1 and type 2 TNFα receptors [(soluble TNFα receptors (sTNFR)]. Levels of survival-oriented soluble TNFR2 (sTNFR2) always exceeded those of death-oriented sTNFR1. When exposed to TNFα at its IC50 value, preconditioned cardiomyocytes showed an increased release of sTNFR2 but not sTNFR1. These results denoted that preconditioning by "low TNFα" helped cardiomyocyte to withstand toxicity from "high TNFα" or other agents. These results also suggested that beneficial or detrimental effects of anti-TNFα agents might well depend on whether these agents spared or intercepted discrete amounts of TNFα that preconditioned cardiomyocytes and made them more resistant to high concentrations of TNFα.

Antimicrobial and antioxidant activity of kaempferol rhamnoside derivatives from Bryophyllum pinnatum

PubMed Central

2012-01-01

Background Bryophyllum pinnatum (Lank.) Oken (Crassulaceae) is a perennial succulent herb widely used in traditional medicine to treat many ailments. Its wide range of uses in folk medicine justifies its being called "life plant" or "resurrection plant", prompting researchers' interest. We describe here the isolation and structure elucidation of antimicrobial and/or antioxidant components from the EtOAc extract of B. pinnatum. Results The methanol extract displayed both antimicrobial activities with minimum inhibitory concentration (MIC) values ranging from 32 to 512 μg/ml and antioxidant property with an IC50 value of 52.48 μg/ml. Its partition enhanced the antimicrobial activity in EtOAc extract (MIC = 16-128 μg/ml) and reduced it in hexane extract (MIC = 256-1024 μg/ml). In addition, this process reduced the antioxidant activity in EtOAc and hexane extracts with IC50 values of 78.11 and 90.04 μg/ml respectively. Fractionation of EtOAc extract gave seven kaempferol rhamnosides, including; kaempferitrin (1), kaempferol 3-O-α-L-(2-acetyl)rhamnopyranoside-7-O-α-L-rhamnopyranoside (2), kaempferol 3-O-α-L-(3-acetyl)rhamnopyranoside-7-O-α-L-rhamnopyranoside (3), kaempferol 3-O-α-L-(4-acetyl)rhamnopyranoside-7-O-α-L-rhamnopyranoside (4), kaempferol 3-O-α-D- glucopyranoside-7-O-α-L-rhamnopyranoside (5), afzelin (6) and α-rhamnoisorobin (7). All these compounds, except 6 were isolated from this plant for the first time. Compound 7 was the most active, with MIC values ranging from 1 to 2 μg/ml and its antioxidant activity (IC50 = 0.71 μg/ml) was higher than that of the reference drug (IC50 = 0.96 μg/ml). Conclusion These findings demonstrate that Bryophyllum pinnatum and some of its isolated compounds have interesting antimicrobial and antioxidant properties, and therefore confirming the traditional use of B. pinnatum in the treatment of infectious and free radical damages. PMID:22433844

In vitro anti-glycation and anti-oxidant properties of synthesized Schiff bases.

PubMed

Jhaumeer-Laulloo, Sabina; Bhowon, Minu Gupta; Mungur, Shabneez; Mahomoodally, Mohamad Fawzi; Subratty, Anwar Hussein

2012-05-01

A series of mono, bis and mixed Schiff bases (1-7) were synthesised and evaluated for potential anti-glycation and anti-oxidant activities using the bovine serum albumin-glucose assay and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical assay respectively. All compounds showed significant (p<0.05) antiglycating activities with IC50 values (4.02x10(-24)±0.1-2.88x10(-1)±1.35 mM) which were lower than the standard positive control aminoguanidine (IC50: 1.51x10(-3)±2.11 mM). Moreover, compounds 1-7 were found to possess significant (p<0.05) DPPH radical scavenging properties with SC50 values (1.31x10(-19)±0.05 to 2.25x10(-1)±1.24 mM) lower than the standard ascorbic acid (SC50: 5.50x10(-3)±2.11 mM). Compound 6 was found to be the most potent anti-glycating molecule (IC50 value: 4.02x10(-24)±0.1 mM) while compound 5 was the most potent anti-oxidant molecule (SC50: 1.31x10(-19)±0.05 mM); both being significantly lower (p<0.05) than the respective positive controls used. The present data showed that the number of phenolic OH together with structural changes influence both the anti-glycation and anti-oxidant observed herein. This study provides for the first time a series of potential template molecules for possible pharmaceutical applications that warrant further investigation as potential anti-glycation and anti-oxidant agents which could be of importance in metabolic diseases including diabetes mellitus.

Synthesis of novel amides based on acridone scaffold with interesting antineoplastic activity.

PubMed

Mahajan, Anand A; Rane, Rajesh A; Amritkar, Anish A; Naphade, Shital S; Miniyar, Pankaj B; Bangalore, Pavan Kumar; Karpoormath, Rajshekhar

2015-01-01

In search of novel cytotoxic agents based on acridone scaffold, twenty five derivatives of acridone-2- carboxamide were synthesized and evaluated against a panel of eleven cancer cell lines by using MTT assay. Amides, A5 and A8 (IC50 = 0.3 µM) exhibited good cytotoxicity against MCF7. Compound A22 (IC50 = 4.3 µM) was found to be selectively cytotoxic against cancer cell line MCF7 and KB403. Particularly, promising cytotoxic activities were shown by amides A6 (IC50 = 0.7 µM), A16 (IC50 = 6.3 µM), A8 (IC50 = 0.9 µM ), A21 (IC50 = 1.3 µM), A5 (IC50 = 2.9 µM), A8 (IC50 = 2.8 µM), A14 (IC50 = 0.8 µM), A9 (IC50 = 0.8 µM) and A8 (IC50 = 0.4 µM) against cell lines; PA1, WRL68, CaCO2, TK-10, K-562, PC-3, HOP-92, ECV-304 and UACC-257, respectively. The favorable cytotoxic profile and non-toxicity towards normal human cells displayed by the derivative revealed their potential for further anticancer drug developments.

Utilization of Nitrophenylphosphates and Oxime-Based Ligation for the Development of Nanomolar Affinity Inhibitors of the Yersinia Pestis Outer Protein H (YopH) Phosphatase†, §, ¶

PubMed Central

Bahta, Medhanit; Lountos, George T.; Dyas, Beverly; Kim, Sung-Eun; Ulrich, Robert G.; Waugh, David S.; Burke, Terrence R.

2011-01-01

Our current study reports the first KM optimization of a library of nitrophenylphosphate-containing substrates for generating an inhibitor lead against the Yersinia pestis outer protein phosphatase (YopH). A high activity substrate identified by this method (KM = 80 μM was converted from a substrate into an inhibitor by replacement of its phosphate group with difluoromethylphosphonic acid and by attachment of an aminooxy handle for further structural optimization by oxime-ligation. A co-crystal structure of this aminooxy-containing platform in complex with YopH allowed the identification of a conserved water molecule proximal to the aminooxy group that was subsequently employed for the design of furanyl-based oxime derivatives. By this process, a potent (IC50 = 190 nM) and non-promiscuous inhibitor was developed with good YopH selectivity relative to a panel of phosphatases. The inhibitor showed significant inhibition of intracellular Y. pestis replication at a non-cytotoxic concentration. The current work presents general approaches to PTP inhibitor development that may be useful beyond YopH. PMID:21443195

Discovery of Brigatinib (AP26113), a Phosphine Oxide-Containing, Potent, Orally Active Inhibitor of Anaplastic Lymphoma Kinase.

PubMed

Huang, Wei-Sheng; Liu, Shuangying; Zou, Dong; Thomas, Mathew; Wang, Yihan; Zhou, Tianjun; Romero, Jan; Kohlmann, Anna; Li, Feng; Qi, Jiwei; Cai, Lisi; Dwight, Timothy A; Xu, Yongjin; Xu, Rongsong; Dodd, Rory; Toms, Angela; Parillon, Lois; Lu, Xiaohui; Anjum, Rana; Zhang, Sen; Wang, Frank; Keats, Jeffrey; Wardwell, Scott D; Ning, Yaoyu; Xu, Qihong; Moran, Lauren E; Mohemmad, Qurish K; Jang, Hyun Gyung; Clackson, Tim; Narasimhan, Narayana I; Rivera, Victor M; Zhu, Xiaotian; Dalgarno, David; Shakespeare, William C

2016-05-26

In the treatment of echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase positive (ALK+) non-small-cell lung cancer (NSCLC), secondary mutations within the ALK kinase domain have emerged as a major resistance mechanism to both first- and second-generation ALK inhibitors. This report describes the design and synthesis of a series of 2,4-diarylaminopyrimidine-based potent and selective ALK inhibitors culminating in identification of the investigational clinical candidate brigatinib. A unique structural feature of brigatinib is a phosphine oxide, an overlooked but novel hydrogen-bond acceptor that drives potency and selectivity in addition to favorable ADME properties. Brigatinib displayed low nanomolar IC50s against native ALK and all tested clinically relevant ALK mutants in both enzyme-based biochemical and cell-based viability assays and demonstrated efficacy in multiple ALK+ xenografts in mice, including Karpas-299 (anaplastic large-cell lymphomas [ALCL]) and H3122 (NSCLC). Brigatinib represents the most clinically advanced phosphine oxide-containing drug candidate to date and is currently being evaluated in a global phase 2 registration trial.

Cyclic RGD peptidomimetics containing 4- and 5-amino-cyclopropane pipecolic acid (CPA) templates as dual αVβ3 and α5β1 integrin ligands.

PubMed

Sernissi, Lorenzo; Trabocchi, Andrea; Scarpi, Dina; Bianchini, Francesca; Occhiato, Ernesto G

2016-02-15

4-Amino- and 5-amino-cyclopropane pipecolic acids (CPAs) with cis relative stereochemistry between the carboxylic and amino groups were used as templates to prepare cyclic peptidomimetics containing the RGD sequence as possible integrin binders. The peptidomimetic c(RGD8) built on the 5-amino-CPA displayed an inhibition activity (IC50=2.4nM) toward the αvβ3 integrin receptor (expressed in M21 human melanoma cell line) comparable to that of the most potent antagonists reported so far and it was ten times more active than the corresponding antagonist c(RGD7) derived from the isomeric 4-amino-CPA. Both compounds were also nanomolar ligands of the α5β1 integrin (expressed in human erythroleukemia cell line K562). These results suggest that the CPA-derived templates are suitable for the preparation of dual αvβ3 and α5β1 ligands to suppress integrin-mediated events as well as for targeted drug delivery in cancer therapy. Copyright © 2015 Elsevier Ltd. All rights reserved.

Discovery of 4-aryl-N-arylcarbonyl-2-aminothiazoles as Hec1/Nek2 inhibitors. Part I: optimization of in vitro potencies and pharmacokinetic properties.

PubMed

Lee, Ying-Shuan E; Chuang, Shih-Hsien; Huang, Lynn Y L; Lai, Chun-Liang; Lin, Yu-Hsiang; Yang, Ju-Ying; Liu, Chia-Wei; Yang, Sheng-chuan; Lin, Her-Sheng; Chang, Chia-chi; Lai, Jun-Yu; Jian, Pei-Shiou; Lam, King; Chang, Jia-Ming; Lau, Johnson Y N; Huang, Jiann-Jyh

2014-05-22

A series of 4-aryl-N-arylcarbonyl-2-aminothiazoles of scaffold 4 was designed and synthesized as Hec1/Nek2 inhibitors. Structural optimization of 4 led to compound 32 bearing C-4' 4-methoxyphenoxy and 4-(o-fluoropyridyl)carbonyl groups that showed low nanomolar in vitro antiproliferative activity (IC50: 16.3-42.7 nM), high intravenous AUC (64.9 μM·h, 2.0 mg/kg) in SD rats, and significant in vivo antitumor activity (T/C = 32%, 20 mg/kg, IV) in mice bearing human MDA-MB-231 xenografts. Cell responses resulting from Hec1/Nek2 inhibition were observed in cells treated with 32, including a reduced level of Hec1 coimmunoprecipitated with Nek2, degradation of Nek2, mitotic abnormalities, and apoptosis. Compound 32 showed selectivity toward cancer cells over normal phenotype cells and was inactive in a [(3)H]astemizole competitive binding assay for hERG liability screening. Therefore, 32 is as a good lead toward the discovery of a preclinical candidate targeting Hec1/Nek2 interaction.

Crystallographic Study of a Novel Sub-Nanomolar Inhibitor Provides Insight on the Binding Interactions of Alkenyldiarylmethanes with Human Immunodeficiency Virus-1 (HIV-1) Reverse Transcriptase†

PubMed Central

Cullen, Matthew D.; Ho, William C.; Bauman, Joseph D.; Das, Kalyan; Arnold, Eddy; Hartman, Tracy L.; Watson, Karen M.; Buckheit, Robert W.; Pannecouque, Christophe; De Clercq, Erik; Cushman, Mark

2009-01-01

Two crystal structures have been solved for separate complexes of alkenyldiarylmethane (ADAM) non-nucleoside reverse transcriptase inhibitors (NNRTI) 3 and 4 with HIV-1 reverse transcriptase (RT). The structures reveal inhibitor binding is exclusively hydrophobic in nature and the shape of the inhibitor-bound NNRTI binding pocket is unique among other reported inhibitor-RT crystal structures. Primarily, ADAMs 3 and 4 protrude from a large gap in the backside of the binding pocket, placing portions of the inhibitors unusually close to the polymerase active site and allowing 3 to form a weak hydrogen bond with Lys223. The lack of additional stabilizing interactions, beyond the observed hydrophobic surface contacts, between 4 and RT is quite perplexing given the extreme potency of the compound (IC50 ≤ nM). ADAM 4 was designed to be hydrolytically stable in blood plasma, and an investigation of its hydrolysis in rat plasma demonstrated it has a significantly prolonged half-life in comparison to ADAM lead compounds 1 and 2. PMID:19775161

In vitro antimalarial activity of different extracts of Eremostachys macrophylla Montbr. & Auch.

PubMed

Asnaashari, Solmaz; Heshmati Afshar, Fariba; Ebrahimi, Atefeh; Bamdad Moghadam, Sedigheh; Delazar, Abbas

2015-01-01

The risk of drug resistance and the use of medicinal plants in malaria prevention and treatment have led to the search for new antimalarial compounds with natural origin. In the current study, six extracts with different polarity from aerial parts and rhizomes of Eremostachys macrophylla Montbr. & Auch., were screened for their antimalarial properties by cell-free β-hematin formation assay. Dichloromethane (DCM) extracts of both parts of plant showed significant antimalarial activities with IC50 values of 0.797 ± 0.016 mg/mL in aerial parts and 0.324 ± 0.039 mg/mL in rhizomes compared to positive control (Chloroquine, IC50 = 0.014 ± 0.003 mg/mL, IC90 = 0.163 ± 0.004 mg/mL). Bioactivity-guided fractionation of the most potent part (DCM extract of rhizomes) by vacuum liquid chromatography (VLC) afforded seven fractions. Sixty percent ethyl acetate/n-hexane fraction showed considerable antimalarial activity with IC50 value of 0.047 ± 0.0003 mg/mL. From 6 extracts with different polarity of E. macrophylla,s aerial parts and rhizomes, the DCM extract of both parts were the most active extract in this assay. The preliminary phytochemical study on the VLC fractions of the most potent part persuades us to focus on purifying the active components of these extracts and to conduct further investigation towards in vivo evaluation.

[Cytotoxicity of chemicals used in household products: 1997- 2004].

PubMed

Ikarashi, Yoshiaki; Kaniwa, Masa-aki; Tsuchiya, Toshie

2005-01-01

The cytotoxicities of chemicals used in household products were evaluated using a neutral red (NR) uptake assay. The chemicals tested during 1997-2004 were rubber additives (accelerators, antioxidants and retarders), solvents, plasticizers and biocides, such as antimicrobials, fungicides, preservatives used in paints, paper, wood and plastic products. The cytotoxicity potential of each chemical was classified by determining the concentrations inducing 50% reduction of NR uptake into Chinese hamster fibroblast V79 cells compared to control (IC50). In vivo eye irritancy of each chemical was estimated by the IC50 value. Most biocides tested showed strong cytotoxicity and had a high probability of inducing strong eye irritation.

Pharmacological profile of zacopride and new quaternarized fluorobenzamide analogues on mammalian α7 nicotinic acetylcholine receptor.

PubMed

Bourdin, Céline M; Lebreton, Jacques; Mathé-Allainmat, Monique; Thany, Steeve H

2015-08-15

From quaternarization of quinuclidine enantiomers of 2-fluoro benzamide LMA10203 in dichloromethane, the corresponding N-chloromethyl derivatives LMA10227 and LMA10228 were obtained. Here, we compared the agonist action of known zacopride and its 2-fluoro benzamide analogues, LMA10203, LMA10227 and LMA10228 against mammalian homomeric α7 nicotinic acetylcholine receptor expressed in Xenopus oocytes. We found that LMA10203 was a partial agonist of α7 receptor with a pEC50 value of 4.25 ± 0.06 μM whereas LMA10227 and LMA10228 were poorly active on α7 homomeric nicotinic receptor. LMA10227 and LMA10228 were identified as antagonists of acetylcholine-induced currents with IC50 values of 28.4 μM and 39.3 μM whereas LMA10203 and zacopride possessed IC50 values of 8.07 μM and 7.04 μM, respectively. Moreover, despite their IC50 values, LMA10227 was the most potent inhibitor of nicotine-induced current amplitudes (65.7 ± 2.1% inhibition). LMA10203 and LMA10228 had the same inhibitory effects (26.5 ± 7.5% and 33.2 ± 4.1%, respectively), whereas zacopride had no significant inhibitory effect (4.37 ± 4%) on nicotine-induced responses. Our results revealed different pharmacological properties between the four compounds on acetylcholine and nicotine currents. The mode of action of benzamide compounds may need to be reinterpreted with respect to the potential role of α7 receptor. Copyright © 2015 Elsevier Ltd. All rights reserved.

The effect of coniine on presynaptic nicotinic receptors.

PubMed

Erkent, Ulkem; Iskit, Alper B; Onur, Rustu; Ilhan, Mustafa

2016-01-01

Toxicity of coniine, an alkaloid of Conium maculatum (poison hemlock), is manifested by characteristic nicotinic clinical signs including excitement, depression, hypermetria, seizures, opisthotonos via postsynaptic nicotinic receptors. There is limited knowledge about the role of presynaptic nicotinic receptors on the pharmacological and toxicological effects of coniine in the literature. The present study was undertaken to evaluate the possible role of presynaptic nicotinic receptors on the pharmacological and toxicological effects of coniine. For this purpose, the rat anococcygeus muscle and guinea-pig atria were used in vitro. Nicotine (100 μM) elicited a biphasic response composed of a relaxation followed by contraction through the activation of nitrergic and noradrenergic nerve terminals in the phenylephrine-contracted rat anococcygeus muscle. Coniine inhibited both the nitrergic and noradrenergic response in the muscle (-logIC(50) = 3.79 ± 0.11 and -logIC(50) = 4.57 ± 0.12 M, respectively). The effect of coniine on nicotinic receptor-mediated noradrenergic transmission was also evaluated in the guinea-pig atrium (-logIC(50) = 4.47 ± 0.12 M) and did not differ from the -logIC(50) value obtained in the rat anococcygeus muscle. This study demonstrated that coniine exerts inhibitory effects on nicotinic receptor-mediated nitrergic and noradrenergic transmitter response.

Structures and bioactivities of seven flavonoids from Osmanthus fragrans 'Jinqiu' essential oil extraction residues.

PubMed

Zhou, Jiang-Lian; Fang, Xian-Ying; Wang, Jing-Qiu; Zhao, Lin-Guo; Li, Yi; Tang, Feng; Yue, Yong-De

2018-03-01

Osmanthus fragrans are well-known for their fragrance, but it is wasteful if to discard O. fragrans flower after extracting their essential oils. In this paper, we found that O. fragrans flower residues were rich in flavonoids. Six flavonoids and one phenylethanoid glycoside were isolated from the ethanol extract of O. fragrans flower residues, identified as quercetin (1), rutin (2), verbascoside (3), genistin (4), kaempferol (5), isorhamnetin (6) and naringin (7). In bioactivity study, kaempferol (IC 50  = 1.43 μg/mL) showed the best anti-inflammatory activity. Isorhamnetin, quercetin, kaempferol, verbascoside and rutin (the values of IC 50 were 18.30, 11.05, 16.88, 20.21 and 22.76 μg/mL, respectively) showed excellent DPPH free radical scavenging activity. Verbascoside performed relatively well at inhibiting the growth of both CT26 colonic carcinoma cells (IC 50  = 46.87 μg/mL) and HepG2 hepatocarcinoma cells (IC 50  = 30.58 μg/mL). In addition, quercetin and kaempferol showed strong anti-proliferation activity against HepG2 cells.

Evaluation of the anticancer potential of six herbs against a hepatoma cell line

PubMed Central

2012-01-01

Background Six herbs in the Plant Genetics Conservation Project that have been used as complementary medicines were chosen on the basis of their medicinal value, namely Terminalia mucronata, Diospyros winitii, Bridelia insulana, Artabotrys harmandii, Terminallia triptera, and Croton oblongifolius. This study aims to evaluate the potential anticancer activity of 50% ethanol-water extracts of these six herbs. Methods Fifty percent ethanol-water crude extracts of the six herbs were prepared. The cytotoxicity of the herbal extracts relative to that of melphalan was evaluated using a hepatoma cell line (HepG2), and examined by neutral red assays and apoptosis induction by gel electrophoresis and flow cytometry after 24 h. Results A significant difference was found between the cytotoxicity of the 50% ethanol-water crude extracts and melphalan (P = 0.000). The 50% ethanol-water crude extracts of all six herbs exhibited cytotoxicity against HepG2 cells, with IC50 values ranging from 100 to 500 μg/mL. The extract of T. triptera showed the highest cytotoxicity with an IC50 of 148.7 ± 12.3 μg/mL, while melphalan had an IC50 of 39.79 ± 7.62 μg/mL. The 50% ethanol-water crude extracts of D. winitii and T. triptera, but not A. harmandii, produced a DNA ladder. The 50% ethanol-water crude extracts of D. winitii, T. triptera, and A. harmandii induced apoptosis detected by flow cytometry. Conclusion The 50% ethanol-water crude extracts of D. winitii, T. triptera, and A. harmandii showed anticancer activity in vitro. PMID:22682026

Doxorubicin-anti-carcinoembryonic antigen immunoconjugate activity in vitro.

PubMed

Richardson, V J; Ford, C H; Tsaltas, G; Gallant, M E

1989-04-01

An in vitro model consisting of a series of 11 human cancer cell lines with varying density of expression of membrane carcinoembryonic antigen (CEA) has been used to evaluate conjugates of doxorubicin (Adriamycin) covalently linked by a carbodiimide method to goat polyclonal antibodies and mouse monoclonal antibodies to CEA. Conjugates were produced which retained both antigen binding and drug cytotoxicity. IC50 values were determined for free drug, free drug mixed with unconjugated antibodies and for the immunoconjugates. Cell lines that were very sensitive to free drug (IC50 less than 100 ng/ml) were also found to be highly sensitive to conjugated drug and similarly cell lines resistant to drug (IC50 greater than 1,000 ng/ml) were also resistant to conjugated drug. Although there was no correlation between CEA expression and conjugates efficacy, competitive inhibition studies using autologous antibody to block conjugate binding to cells indicated immunoconjugates specificity for the CEA target.

New chemical constituents from the Piper betle Linn. (Piperaceae).

PubMed

Atiya, Akhtar; Sinha, Barij Nayan; Ranjan Lal, Uma

2018-05-01

The phytochemical investigation of chloroform extract from Piper betle var. haldia, Piperaceae, leaves has resulted in the isolation of two new chemical constituents which were identified as 1-n-dodecanyloxy resorcinol (H1) and desmethylenesqualenyl deoxy-cepharadione-A (H4), on the basis of spectroscopic data 1D NMR ( 1 H and 13 C) and 2D NMR ( 1 H- 1 H COSY and HMBC) as well as ESI-MS, FT-IR and HR-ESI-MS analyses. Compounds H1 and H4 showed excellent antioxidant DPPH free radical scavenging activity with IC 50 values of 7.14 μg/mL and 8.08 μg/mL compared to ascorbic acid as a standard antioxidant drug with IC 50 value of 2.52 μg/mL, respectively. Evaluation of cytotoxic activity against human hepatoma cell line (PLC-PRF-5) showed moderate effect with the GI 50 values of 35.12 μg/mL for H1, 31.01 μg/mL for H4, compared to Doxorubicin ® as a standard cytotoxic drug with GI 50 value of 18.80 μg/mL.

Asphodosides A-E, anti-MRSA metabolites from Asphodelus microcarpus.

PubMed

Ghoneim, Mohammed M; Elokely, Khaled M; El-Hela, Atef A; Mohammad, Abd-Elsalam I; Jacob, Melissa; Radwan, Mohamed M; Doerksen, Robert J; Cutler, Stephen J; Ross, Samir A

2014-09-01

Bioassay guided fractionation of the ethanolic extract of Asphodelus microcarpus Salzm. et Viv. (Xanthorrhoeaceae or Asphodelaceae) resulted in isolation of five compounds identified as asphodosides A-E (1-5). Compounds 2-4 showed activity against methicillin resistant Staphylococcus aureus (MRSA) with IC50 values of 1.62, 7.0 and 9.0μg/mL, respectively. They also exhibited activity against Staphylococcus aureus (non-MRSA) with IC50 values of 1.0, 3.4 and 2.2μg/mL, respectively. The structure elucidation of isolated metabolites was carried out using spectroscopic data (1D and 2D NMR), optical rotation and both experimental and calculated electronic circular dichroism (ECD). Copyright © 2014 Elsevier Ltd. All rights reserved.

Molecular Docking Study on Galantamine Derivatives as Cholinesterase Inhibitors.

PubMed

Atanasova, Mariyana; Yordanov, Nikola; Dimitrov, Ivan; Berkov, Strahil; Doytchinova, Irini

2015-06-01

A training set of 22 synthetic galantamine derivatives binding to acetylcholinesterase was docked by GOLD and the protocol was optimized in terms of scoring function, rigidity/flexibility of the binding site, presence/absence of a water molecule inside and radius of the binding site. A moderate correlation was found between the affinities of compounds expressed as pIC50 values and their docking scores. The optimized docking protocol was validated by an external test set of 11 natural galantamine derivatives and the correlation coefficient between the docking scores and the pIC50 values was 0.800. The derived relationship was used to analyze the interactions between galantamine derivatives and AChE. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Identification of new potent inhibitor of aldose reductase from Ocimum basilicum.

PubMed

Bhatti, Huma Aslam; Tehseen, Yildiz; Maryam, Kiran; Uroos, Maliha; Siddiqui, Bina S; Hameed, Abdul; Iqbal, Jamshed

2017-12-01

Recent efforts to develop cure for chronic diabetic complications have led to the discovery of potent inhibitors against aldose reductase (AKR1B1, EC 1.1.1.21) whose role in diabetes is well-evident. In the present work, two new natural products were isolated from the ariel part of Ocimum basilicum; 7-(3-hydroxypropyl)-3-methyl-8-β-O-d-glucoside-2H-chromen-2-one (1) and E-4-(6'-hydroxyhex-3'-en-1-yl)phenyl propionate (2) and confirmed their structures with different spectroscopic techniques including NMR spectroscopy etc. The isolated compounds (1, 2) were evaluated for in vitro inhibitory activity against aldose reductase (AKR1B1) and aldehyde reductase (AKR1A1). The natural product (1) showed better inhibitory activity for AKR1B1 with IC 50 value of 2.095±0.77µM compare to standard sorbinil (IC 50 =3.14±0.02µM). Moreover, the compound (1) also showed multifolds higher activity (IC 50 =0.783±0.07µM) against AKR1A1 as compared to standard valproic acid (IC 50 =57.4±0.89µM). However, the natural product (2) showed slightly lower activity for AKR1B1 (IC 50 =4.324±1.25µM). Moreover, the molecular docking studies of the potent inhibitors were also performed to identify the putative binding modes within the active site of aldose/aldehyde reductases. Copyright © 2017 Elsevier Inc. All rights reserved.

Synthesis of N4-(Substituted phenyl)-N4-alkyl/desalkyl-9H-pyrimido[4,5-b]indole-2,4-diamines and Identification of New Microtubule Disrupting Compounds that are Effective against Multidrug Resistant Cells1

PubMed Central

Gangjee, Aleem; Zaware, Nilesh; Devambatla, Ravi Kumar Vyas; Raghavan, Sudhir; Westbrook, Cara D.; Dybdal-Hargreaves, Nicholas F.; Hamel, Ernest; Mooberry, Susan L.

2013-01-01

A series of fourteen N4-(substituted phenyl)-N4-methyl/desmethyl-9H-pyrimido[4,5-b]indole-2,4-diamines was synthesized as potential microtubule targeting agents. The synthesis involved a Fisher indole cyclization of 2-amino-6-hydrazinylpyrimidin-4(3H)-one with cyclohexanone, followed by oxidation, chlorination and displacement with appropriate anilines. Compounds 6, 14 and 15 had low nanomolar potency against MDA-MB-435 tumor cells and depolymerized microtubules. Compound 6 additionally had nanomolar GI50 values against 57 of the NCI 60-tumor panel cell lines. Mechanistic studies showed that 6 inhibited tubulin polymerization and [3H]colchicine binding to tubulin. The most potent compounds were all effective in cells expressing P-glycoprotein or the βIII isotype of tubulin, which have been associated with clinical drug reisistence. Modeling studies provided the potential interactions of 6, 14 and 15 within the colchicine site. PMID:23332369

Steroidal constituents from the edible sea urchin Diadema savignyi Michelin induce apoptosis in human cancer cells.

PubMed

Thao, Nguyen Phuong; Luyen, Bui Thi Thuy; Kim, Eun Ji; Kang, Jung Il; Kang, Hee Kyoung; Cuong, Nguyen Xuan; Nam, Nguyen Hoai; Kiem, Phan Van; Minh, Chau Van; Kim, Young Ho

2015-01-01

Bioassay-directed fractionation and purification were used to isolate 12 steroids (1-12) from a CH(2)Cl(2) extract of the edible Vietnamese sea urchin Diadema savignyi Michelin. The cytotoxic activity of the CH(2)Cl(2) extract and 12 steroids was evaluated in three human cancer cell lines (HL-60, PC-3, and SNU-C5). Relative to the effects of the positive control, mitoxantrone, the CH(2)Cl(2) extract (with an inhibitory concentration of 50% [IC(50)] values ranging from 1.37±0.15 to 3.11±0.15 μg/mL) and compounds 2 (with IC(50) values ranging from 5.29±0.11 to 6.80±0.67 μM) and 11 (with IC(50) values ranging from 4.95±0.07 to 6.99±0.28 μM) exhibited potent cytotoxic effects against all three tested human cancer cell lines. In addition, the CH(2)Cl(2) extract and compounds 2 and 11 were found to induce apoptosis. The induction of apoptosis was accompanied by alterations of the apoptosis-related protein expression, inactivation of ERK1/2 mitogen-activated protein kinase signaling, and decreased c-Myc expression. These data suggest that compounds 2 and 11 from the edible sea urchin D. savignyi may have potential for the treatment of colon cancer, leukemia, and prostate cancer as complementary cancer remedies.

Cannabidiol-2',6'-dimethyl ether, a cannabidiol derivative, is a highly potent and selective 15-lipoxygenase inhibitor.

PubMed

Takeda, Shuso; Usami, Noriyuki; Yamamoto, Ikuo; Watanabe, Kazuhito

2009-08-01

The inhibitory effect of nordihydroguaiaretic acid (NDGA) (a nonselective lipoxygenase (LOX) inhibitor)-mediated 15-LOX inhibition has been reported to be affected by modification of its catechol ring, such as methylation of the hydroxyl group. Cannabidiol (CBD), one of the major components of marijuana, is known to inhibit LOX activity. Based on the phenomenon observed in NDGA, we investigated whether or not methylation of CBD affects its inhibitory potential against 15-LOX, because CBD contains a resorcinol ring, which is an isomer of catechol. Although CBD inhibited 15-LOX activity with an IC(50) value (50% inhibition concentration) of 2.56 microM, its monomethylated and dimethylated derivatives, CBD-2'-monomethyl ether and CBD-2',6'-dimethyl ether (CBDD), inhibited 15-LOX activity more strongly than CBD. The number of methyl groups in the resorcinol moiety of CBD (as a prototype) appears to be a key determinant for potency and selectivity in inhibition of 15-LOX. The IC(50) value of 15-LOX inhibition by CBDD is 0.28 microM, and the inhibition selectivity for 15-LOX (i.e., the 5-LOX/15-LOX ratio of IC(50) values) is more than 700. Among LOX isoforms, 15-LOX is known to be able to oxygenate cholesterol esters in the low-density lipoprotein (LDL) particle (i.e., the formation of oxidized LDL). Thus, 15-LOX is suggested to be involved in development of atherosclerosis, and CBDD may be a useful prototype for producing medicines for atherosclerosis.

One Pot Selective Arylation of 2-Bromo-5-Chloro Thiophene; Molecular Structure Investigation via Density Functional Theory (DFT), X-ray Analysis, and Their Biological Activities.

PubMed

Rasool, Nasir; Kanwal, Aqsa; Rasheed, Tehmina; Ain, Quratulain; Mahmood, Tariq; Ayub, Khurshid; Zubair, Muhammad; Khan, Khalid Mohammed; Arshad, Muhammad Nadeem; M Asiri, Abdullah; Zia-Ul-Haq, Muhammad; Jaafar, Hawa Z E

2016-06-28

Synthesis of 2,5-bisarylthiophenes was accomplished by sequential Suzuki cross coupling reaction of 2-bromo-5-chloro thiophenes. Density functional theory (DFT) studies were carried out at the B3LYP/6-31G(d, p) level of theory to compare the geometric parameters of 2,5-bisarylthiophenes with those from X-ray diffraction results. The synthesized compounds are screened for in vitro bacteria scavenging abilities. At the concentration of 50 and 100 μg/mL, compounds 2b, 2c, 2d, 3c, and 3f with IC50-values of 51.4, 52.10, 58.0, 56.2, and 56.5 μg/mL respectively, were found most potent against E. coli. Among all the synthesized compounds 2a, 2d, 3c, and 3e with the least values of IC50 77, 76.26, 79.13 μg/mL respectively showed significant antioxidant activities. Almost all of the compounds showed good antibacterial activity against Escherichia coli, whereas 2-chloro-5-(4-methoxyphenyl) thiophene (2b) was found most active among all synthesized compound with an IC50 value of 51.4 μg/mL. All of the synthesized compounds were screened for nitric oxide scavenging activity as well. Frontier molecular orbitals (FMOs) and molecular electrostatic potentials of the target compounds were also studied theoretically to account for their relative reactivity.

A role for the anandamide membrane transporter in TRPV1-mediated neurosecretion from trigeminal sensory neurons

PubMed Central

Price, Theodore J.; Patwardhan, Amol M.; Flores, Christopher M.; Hargreaves, Kenneth M.

2007-01-01

Many n-acylethanolamines utilize the anandamide membrane transporter (AMT) to gain facilitated access to the intracellular compartment, hence, we hypothesized that this mechanism might be important for anandamide (AEA)- and N-arachidonoyl-dopamine (NADA)-evoked CGRP release from cultured trigeminal ganglion (TG) neurons. Using [14C]AEA we demonstrated that TG neurons transported AEA in a FAAH- and AMT-inhibitable fashion. Although TRPV1-positive TG neurons were found to express fatty acid amide hydrolase, the application of FAAH inhibitors had no effect on AEA-evoked CGRP release. In contrast, application of the AMT inhibitors OMDM-2 or VDM-11 significantly reduced the potency and efficacy of AEA-, NADA- and capsaicin-evoked CGRP release. Moreover OMDM-2 (IC50 values ranging from 6.4–9.6 μM) and VDM-11 (IC50 values ranging from 5.3–11 μM) inhibited CGRP release evoked by EC80 concentrations of AEA, NADA and CAP and these values were consistent with IC50s obtained for inhibition of uptake. OMDM-2 had no effect on CGRP release per se while VDM-11 evoked CGRP release on its own (EC50 ~35 μM) in a CPZ-insensitive, but ruthenium red (RR)-sensitive fashion. This is the first demonstration that TG sensory neurons possess an AMT-like mechanism suggesting that this mechanism is important for the pharmacological action of AEA and NADA at native TRPV1 channels. PMID:15992578

Multinormal In Vitro Distribution Model Suitable for the Distribution of Plasmodium falciparum Chemosusceptibility to Doxycycline▿

PubMed Central

Briolant, Sébastien; Baragatti, Meili; Parola, Philippe; Simon, Fabrice; Tall, Adama; Sokhna, Cheikh; Hovette, Philippe; Mamfoumbi, Modeste Mabika; Koeck, Jean-Louis; Delmont, Jean; Spiegel, André; Castello, Jacky; Gardair, Jean Pierre; Trape, Jean Francois; Kombila, Maryvonne; Minodier, Philippe; Fusai, Thierry; Rogier, Christophe; Pradines, Bruno

2009-01-01

The distribution and range of 50% inhibitory concentrations (IC50s) of doxycycline were determined for 747 isolates obtained between 1997 and 2006 from patients living in Senegal, Republic of the Congo, and Gabon and patients hospitalized in France for imported malaria. The statistical analysis was designed to answer the specific question of whether Plasmodium falciparum has different phenotypes of susceptibility to doxycycline. A triple normal distribution was fitted to the data using a Bayesian mixture modeling approach. The IC50 geometric mean ranged from 6.2 μM to 11.1 μM according to the geographical origin, with a mean of 9.3 μM for all 747 parasites. The values for all 747 isolates were classified into three components: component A, with an IC50 mean of 4.9 μM (±2.1 μM [standard deviation]); component B, with an IC50 mean of 7.7 μM (±1.2 μM); and component C, with an IC50 mean of 17.9 μM (±1.4 μM). According to the origin of the P. falciparum isolates, the triple normal distribution was found in each subgroup. However, the proportion of isolates predicted to belong to component B was most important in isolates from Gabon and Congo and in isolates imported from Africa (from 46 to 56%). In Senegal, 55% of the P. falciparum isolates were predicted to be classified as component C. The cutoff of reduced susceptibility to doxycycline in vitro was estimated to be 35 μM. PMID:19047651

Prioritizing pharmacokinetic drug interaction precipitants in natural products: application to OATP inhibitors in grapefruit juice

PubMed Central

Johnson, Emily J.; Won, Christina S.; Köck, Kathleen; Paine, Mary F.

2017-01-01

Natural products, including botanical dietary supplements and exotic drinks, represent an ever-increasing share of the health care market. The parallel ever-increasing popularity of self-medicating with natural products increases the likelihood of co-consumption with conventional drugs, raising concerns for unwanted natural product-drug interactions. Assessing the drug interaction liability of natural products is challenging due to the complex and variable chemical composition inherent to these products, necessitating a streamlined preclinical testing approach to prioritize precipitant individual constituents for further investigation. Such an approach was evaluated in the current work to prioritize constituents in the model natural product, grapefruit juice, as inhibitors of intestinal organic anion-transporting peptide (OATP)-mediated uptake. Using OATP2B1-expressing MDCKII cells and the probe substrate estrone 3-sulfate, IC50s were determined for constituents representative of the flavanone (naringin, naringenin, hesperidin), furanocoumarin (bergamottin, 6′,7′-dihydroxybergamottin), and polymethoxyflavone (nobiletin and tangeretin) classes contained in grapefruit juice juice. Nobiletin was the most potent (IC50, 3.7 μM); 6′,7′-dihydroxybergamottin, naringin, naringenin, and tangeretin were moderately potent (IC50, 20–50 μM); and bergamottin and hesperidin were the least potent (IC50, >300 μM) OATP2B1 inhibitors. Intestinal absorption simulations based on physiochemical properties were used to determine ratios of unbound concentration to IC50 for each constituent within enterocytes and to prioritize in order of pre-defined cut-off values. This streamlined approach could be applied to other natural products that contain multiple precipitants of natural product-drug interactions. PMID:28032362

Design, synthesis, kinetic mechanism and molecular docking studies of novel 1-pentanoyl-3-arylthioureas as inhibitors of mushroom tyrosinase and free radical scavengers.

PubMed

Larik, Fayaz Ali; Saeed, Aamer; Channar, Pervaiz Ali; Muqadar, Urooj; Abbas, Qamar; Hassan, Mubashir; Seo, Sung-Yum; Bolte, Michael

2017-12-01

A series of novel 1-pentanoyl-3-arylthioureas was designed as new mushroom tyrosinase inhibitors and free radical scavengers. The title compounds were obtained in excellent yield and characterized by FTIR, 1 H NMR, 13 C NMR and X-ray crystallography in case of compound (4a). The inhibitory effects on mushroom tyrosinase and DPPH were evaluated and it was observed that 1-Pentanoyl-3-(4-methoxyphenyl) thiourea (4f) showed tyrosinase inhibitory activity (IC 50 1.568 ± 0.01 mM) comparable to Kojic acid (IC 50 16.051 ± 1.27 mM). Interestingly compound 4f exhibited higher antioxidant potential compared to other derivatives. The docking studies of synthesized 1-Pentanoyl-3-arylthioureas analogues were also carried out against tyrosinase protein (PDBID 2ZMX) to compare the binding affinities with IC 50 values. The predicted binding affinities are in good agreement with the IC 50 values as compound (4f) showed highest binding affinity (-7.50 kcal/mol) compared to others derivatives. The kinetic mechanism analyzed by Line-weavere Burk plots exhibited that compound (4f) inhibit the enzyme inhibits the tyrosinase non-competitively to form an enzyme inhibitor complex. The inhibition constants Ki calculated from Dixon plots for compound (4f) is 1.10 μM. It was also found from kinetic analysis that derivative 4f irreversible enzyme inhibitor complex. It is proposed on the basis of our investigation that title compound (4f) may serve as lead structure for the design of more potent tyrosinase inhibitors. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Discovery of New Inhibitors of Toxoplasma gondii via the Pathogen Box

PubMed Central

Spalenka, Jérémy; Escotte-Binet, Sandie; Bakiri, Ali; Hubert, Jane; Renault, Jean-Hugues; Velard, Frédéric; Duchateau, Simon; Aubert, Dominique; Huguenin, Antoine

2017-01-01

ABSTRACT Toxoplasma gondii is a cosmopolitan protozoan parasite which affects approximately 30% of the population worldwide. The drugs currently used against toxoplasmosis are few in number and show several limitations, such as drug intolerance, poor bioavailability, or drug resistance mechanism developed by the parasite. Thus, it is important to find new compounds able to inhibit parasite invasion or proliferation. In this study, the 400 compounds of the open-access Pathogen Box, provided by the Medicines for Malaria Venture (MMV) foundation, were screened for their anti-Toxoplasma gondii activity. A preliminary in vitro screening performed over 72 h by an enzyme-linked immunosorbent assay (ELISA) revealed 15 interesting compounds that were effective against T. gondii at 1 μM. Their cytotoxicity was estimated on Vero cells, and their 50% inhibitory concentrations (IC50) were further calculated. As a result, eight anti-Toxoplasma gondii compounds with an IC50 of less than 2 μM and a selectivity index (SI) value of greater than 4 were identified. The most active was MMV675968, showing an IC50 of 0.02 μM and a selectivity index value equal to 275. Two other compounds, MMV689480 and MMV687807, also showed a good activity against T. gondii, with IC50s of 0.10 μM (SI of 86.6) and 0.15 μM (SI of 11.3), respectively. Structure-activity relationships for the eight selected compounds also were discussed on the basis of fingerprinting similarity measurements using the Tanimoto method. The anti-Toxoplasma gondii compounds highlighted here represent potential candidates for the development of new drugs that could be used against toxoplasmosis. PMID:29133550

Discovery of New Inhibitors of Toxoplasma gondii via the Pathogen Box.

PubMed

Spalenka, Jérémy; Escotte-Binet, Sandie; Bakiri, Ali; Hubert, Jane; Renault, Jean-Hugues; Velard, Frédéric; Duchateau, Simon; Aubert, Dominique; Huguenin, Antoine; Villena, Isabelle

2018-02-01

Toxoplasma gondii is a cosmopolitan protozoan parasite which affects approximately 30% of the population worldwide. The drugs currently used against toxoplasmosis are few in number and show several limitations, such as drug intolerance, poor bioavailability, or drug resistance mechanism developed by the parasite. Thus, it is important to find new compounds able to inhibit parasite invasion or proliferation. In this study, the 400 compounds of the open-access Pathogen Box, provided by the Medicines for Malaria Venture (MMV) foundation, were screened for their anti- Toxoplasma gondii activity. A preliminary in vitro screening performed over 72 h by an enzyme-linked immunosorbent assay (ELISA) revealed 15 interesting compounds that were effective against T. gondii at 1 μM. Their cytotoxicity was estimated on Vero cells, and their 50% inhibitory concentrations (IC 50 ) were further calculated. As a result, eight anti- Toxoplasma gondii compounds with an IC 50 of less than 2 μM and a selectivity index (SI) value of greater than 4 were identified. The most active was MMV675968, showing an IC 50 of 0.02 μM and a selectivity index value equal to 275. Two other compounds, MMV689480 and MMV687807, also showed a good activity against T. gondii , with IC 50 s of 0.10 μM (SI of 86.6) and 0.15 μM (SI of 11.3), respectively. Structure-activity relationships for the eight selected compounds also were discussed on the basis of fingerprinting similarity measurements using the Tanimoto method. The anti- Toxoplasma gondii compounds highlighted here represent potential candidates for the development of new drugs that could be used against toxoplasmosis. Copyright © 2018 Spalenka et al.

cis-fumagillin, a new methionine aminopeptidase (type 2) inhibitor produced by Penicillium sp. F2757.

PubMed

Kwon, J Y; Jeong, H W; Kim, H K; Kang, K H; Chang, Y H; Bae, K S; Choi, J D; Lee, U C; Son, K H; Kwon, B M

2000-08-01

Selective inhibition against the yeast MetAP2 (methionine aminopeptidase type 2) was detected in the fermentation broth of a fungus F2757 that was later identified as Penicillium janczewskii. A new compound cis-fumagillin methyl ester (1) was isolated from the diazomethane treated fermentation extracts together with the known compound fumagillin methyl ester (2). The cis-fumagillin methyl ester, a stereoisomer of fumagillin methyl ester at the C2'-C3' position of the aliphatic side chain, selectively inhibited growth of the map1 mutant yeast strain (MetAP1 deletion strain) at a concentration as low as 1 ng. However, the wild type yeast w303 and the mutant map2 (MetAP2 deleted) strains were resistant up to 10 microg of the compound. In enzyme experiments, compound 1 inhibited the MetAP2 with an IC50 value of 6.3 nM, but it did not inhibit the MetAP1 (IC50 >200 microM). Compound 2 also inhibited the MetAP2 with an IC50 value of 9.2 nM and 105 microM against MetAP1.

Cytotoxic activity of erypogein d from erythrina poeppigiana (leguminosae) against cervical cancer (HeLa), breast cancer (MCF-7) and ovarian cancer (SKOV-3) cells

NASA Astrophysics Data System (ADS)

Herlina, T.; Gaffar, S.; Widowati, W.

2018-05-01

Cancer is the uncontrolled growth of abnormal cells and continues to divide rapidly in the body. Current anticancer treatment usually causes many side effects. Natural products are then explored to be new alternatives for cancer treatment. Flavonoids have been known to possess medicinal properties, including anticancer. This study was performed to observe the cytotoxic activity of isoflavanone compound, erypogein D from Erythrina poeppigiana, toward cervical cancer (HeLa), breast cancer (MCF-7) and ovarian cancer (SKOV-3) cells. The cytotoxic activity of erypogein D was tested using MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3- carboxyme-thoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay. The percentage of cell mortality was calculated and the IC50 was analyzed using probit analysis. The result showed that cytotoxic activity of the erypogein D against HeLa, SKOV-3, and MCF-7 cells had an IC50 value 225, 70.74, and 30.12 μM, respectively. Based on IC50 value can be concluded that erypogein D is the most cytotoxic to breast cancer MCF-7 cell. However the cytotoxic activity of erypogein D toward MCF7 is moderate.

Isolation of cholinesterase and β-secretase 1 inhibiting compounds from Lycopodiella cernua.

PubMed

Nguyen, Van Thu; To, Dao Cuong; Tran, Manh Hung; Oh, Sang Ho; Kim, Jeong Ah; Ali, Md Yousof; Woo, Mi-Hee; Choi, Jae Sue; Min, Byung Sun

2015-07-01

Three new serratene-type triterpenoids (1-3) and a new hydroxy unsaturated fatty acid (13) together with nine known compounds (4-12) were isolated from Lycopodiella cernua. The chemical structures were established using NMR, MS, and Mosher's method. Compound 13 showed the most potent inhibitory activity against acetylcholinesterase (AChE) with an IC50 value of 0.22μM. For butyrylcholinesterase (BChE) inhibitory activity, 5 showed the most potent activity with an IC50 value of 0.42μM. Compound 2 showed the most potent activity with an IC50 of 0.23μM for BACE-1 inhibitory activity. The kinetic activities were investigated to determine the type of enzyme inhibition involved. The types of AChE inhibition shown by compounds 4, 5, and 13 were mixed; BChE inhibition by 5 was competitive, while 2 and 6 showed mixed-types. In addition, molecular docking studies were performed to investigate the interaction of these compounds with the pocket sites of AChE. The docking results revealed that the tested inhibitors 3, 4, and 13 were stably present in several pocket domains of the AChE residue. Copyright © 2015 Elsevier Ltd. All rights reserved.

Determination of total phenolic content and antioxidant activitity of methanol extract of Maranta arundinacea L fresh leaf and tuber

NASA Astrophysics Data System (ADS)

Kusbandari, A.; Susanti, H.

2017-11-01

Maranta arundinacea L is one of herbaceous plants in Indonesia which have flavonoid content. Flavonoids has antioxidants activity by inhibition of free radical oxidation reactions. The study aims were to determination total phenolic content and antioxidant activity of methanol extract of fresh leaf and tuber of M. arundinacea L by UV-Vis spectrophotometer. The methanol extracts were obtained with maceration and remaseration method of fresh leaves and tubers. The total phenolic content was assayed with visible spectrophotometric using Folin Ciocalteau reagent. The antioxidant activity was assayed with 1,1-diphenyl-2-picrilhidrazil (DPPH) compared to gallic acid. The results showed that methanol extract of tuber and fresh leaf of M. arundinacea L contained phenolic compound with total phenolic content (TPC) in fresh tuber of 3.881±0.064 (% GAE) and fresh leaf is 6.518±0.163 (% b/b GAE). IC50 value from fresh tuber is 1.780±0.0005 μg/mL and IC50 fresh leaf values of 0.274±0.0004 μg/mL while the standard gallic acid is IC50 of 0.640±0.0002 μg/mL.

Bioactive metabolites from an endophytic Cryptosporiopsis sp. inhabiting Clidemia hirta.

PubMed

Zilla, Mahesh K; Qadri, Masroor; Pathania, Anup S; Strobel, Gary A; Nalli, Yedukondalu; Kumar, Sunil; Guru, Santosh K; Bhushan, Shashi; Singh, Sanjay K; Vishwakarma, Ram A; Riyaz-Ul-Hassan, Syed; Ali, Asif

2013-11-01

An endophytic Cryptosporiopsis sp. was isolated from Clidemia hirta and analyzed for its secondary metabolites that lead to the isolation of three bioactive molecules. The compounds were purified from the culture broth of the fungus and their structures were determined by spectroscopic methods as (R)-5-hydroxy-2-methylchroman-4-one (1), 1-(2,6-dihydroxyphenyl)pentan-1-one (2) and (Z)-1-(2-(2-butyryl-3-hydroxyphenoxy)-6-hydroxyphenyl)-3-hydroxybut-2-en-1-one (3). Compound 1 exhibited significant cytotoxic activity against the human leukemia cell line, HL-60 with an IC50 of 4 μg/ml. This compound induced G2 arrest of the HL-60 cell cycle significantly. In addition, out of these compounds, 2 and 3 were active against several bacterial pathogens. Compound 2 was active against Bacillus cereus, Escherichia coli and Staphylococcus aureus with IC50 values varying from 18 to 30 μg/ml, and compound 3 displayed activity against Pseudomonas fluorescens with an IC50 value of 6 μg/ml. Compounds 2 and 3 are novel whereas compound 1 was reported earlier but the stereochemistry of its C-2 methyl is established for the first time. Copyright © 2013 Elsevier Ltd. All rights reserved.

Comparative evaluation of antiproliferative effects of Brazilian green propolis, its main source Baccharis dracunculifolia, and their major constituents artepillin C and baccharin.

PubMed

de Oliveira, Pollyanna Francielli; de Souza Lima, Ildercílio Mota; Munari, Carla Carolina; Bastos, Jairo Kenupp; da Silva Filho, Ademar Alves; Tavares, Denise Crispim

2014-04-01

This study evaluated the antiproliferative activity of the Brazilian green propolis and Baccharis dracunculifolia extracts and their major compounds artepillin C and baccharin in different tumor cell lines. The lowest IC50 values observed for Brazilian green propolis and B. dracunculifolia extracts were 41.0 ± 4.5 µg/mL for U343 and 44.9 ± 7.1 µg/mL for HepG2, respectively. Regarding artepillin C and baccharin, the lowest IC50 values were 20.1 ± 2.9 for U343 and 13.0 ± 1.5 µg/mL for B16F10, respectively. For the association of artepillin C plus baccharin, the lowest IC50 result was 35.2 ± 0.5 µg/mL for B16F10. Artepillin C and baccharin were more cytotoxic than both Brazilian green propolis and B. dracunculifolia extracts. No additive or synergistic effect was observed for the association of artepillin C plus baccharin. Georg Thieme Verlag KG Stuttgart · New York.

Phytochemical constituents, nutritional values, phenolics, flavonols, flavonoids, antioxidant and cytotoxicity studies on Phaleria macrocarpa (Scheff.) Boerl fruits

PubMed Central

2014-01-01

Background The edible fruits of Phaleria macrocarpa (Scheff.) Boerl are widely used in traditional medicine in Indonesia. It is used to treat a variety of medical conditions such as - cancer, diabetes mellitus, allergies, liver and heart diseases, kidney failure, blood diseases, high blood pressure, stroke, various skin diseases, itching, aches, and flu. Therefore, it is of great interest to determine the biochemical and cytotoxic properties of the fruit extracts. Methods The methanol, hexane, chloroform, ethyl acetate, and water extracts of P. macrocarpa fruits were examined for phytochemicals, physicochemicals, flavonols, flavonoids and phenol content. Its nutritional value (A.O.A.C method), antioxidant properties (DPPH assay) and cytotoxicity (MTT cell proliferation assay) were also determined. Results A preliminary phyotochemical screening of the different crude extracts from the fruits of P. macrocarpa showed the presence secondary metabolites such as of flavonoids, phenols, saponin glycosides and tannins. The ethyl acetate and methanol extracts displayed high antioxidant acitivity (IC50 value of 8.15±0.02 ug/mL) in the DPPH assay comparable to that of the standard gallic acid (IC50 value of 10.8±0.02 ug/mL). Evaluation of cytotoxic activity showed that the crude methanol extract possessed excellent anti-proliferative activity against SKOV-3 (IC50 7.75±2.56 μg/mL) after 72 hours of treatment whilst the hexane and ethyl acetate extracts displayed good cytotoxic effect against both SKOV-3 and MDA-MB231 cell lines. The chloroform extract however, showed selective inhibitory activity in the breast cancer cell line MDA-MB231 (IC50 7.80±1.57 μg/mL) after 48 hours of treatment. There was no cytotoxic effect observed in the Ca Ski cell line and the two normal cell lines (MRC-5 and WRL-68). Conclusion The methanol extract and the ethyl acetate fraction of P. macrocarpa fruits exhibited good nutritional values, good antioxidant and cytotoxic activities, and merits further investigation to identify the specific compound(s) responsible for these activities. PMID:24885709

Biogenesis of silver nanoparticles using endophytic fungus Pestalotiopsis microspora and evaluation of their antioxidant and anticancer activities.

PubMed

Netala, Vasudeva Reddy; Bethu, Murali Satyanarayana; Pushpalatha, Bobbu; Baki, Vijaya Bhaskar; Aishwarya, Sani; Rao, J Venkateswara; Tartte, Vijaya

An endophytic fungal strain isolated from the leaves of Gymnema sylvestre was identified as Pestalotiopsis microspora VJ1/VS1 based on nucleotide sequencing of internal transcribed spacer region (ITS 1-5.8S-ITS 2) of 18S rRNA gene (NCBI accession number KX213894). In this study, an efficient and ecofriendly approach has been reported for the synthesis of silver nanoparticles (AgNPs) using aqueous culture filtrate of P. microspora . Ultraviolet-visible analysis confirmed the synthesis of AgNPs by showing characteristic absorption peak at 435 nm. Fourier transform infrared spectroscopy analysis revealed the presence of phenolic compounds and proteins in the fungal filtrate, which are plausibly involved in the biosynthesis and capping of AgNPs. Transmission electron microscopy (TEM) showed that the AgNPs were spherical in shape of 2-10 nm in size. Selected area electron diffraction and X-ray diffraction studies determined the crystalline nature of AgNPs with face-centered cubic (FCC) lattice phase. Dynamic light scattering analysis showed that the biosynthesized AgNPs possess high negative zeta potential value of -35.7 mV. Biosynthesized AgNPs were proved to be potential antioxidants by showing effective radical scavenging activity against 2,2'-diphenyl-1-picrylhydrazyl and H 2 O 2 radicals with IC 50 values of 76.95±2.96 and 94.95±2.18 µg/mL, respectively. The biosynthesized AgNPs exhibited significant cytotoxic effects against B16F10 (mouse melanoma, IC 50 =26.43±3.41 µg/mL), SKOV3 (human ovarian carcinoma, IC 50 =16.24±2.48 µg/mL), A549 (human lung adenocarcinoma, IC 50 =39.83±3.74 µg/mL), and PC3 (human prostate carcinoma, IC 50 =27.71±2.89 µg/mL) cells. The biosynthesized AgNPs were found to be biocompatible toward normal cells (Chinese hamster ovary cell line, IC 50 =438.53±4.2 µg/mL). Cytological observations on most susceptible SKOV3 cells revealed concentration-dependent apoptotic changes that include cell membrane blebbing, cell shrinkage, pyknotic nuclei, karyorrhexis followed by destructive fragmentation of nuclei. The results together in this study strongly provided a base for the development of potential and versatile biomedical applications of biosynthesized AgNPs in the near future.

Biogenesis of silver nanoparticles using endophytic fungus Pestalotiopsis microspora and evaluation of their antioxidant and anticancer activities

PubMed Central

Netala, Vasudeva Reddy; Bethu, Murali Satyanarayana; Pushpalatha, Bobbu; Baki, Vijaya Bhaskar; Aishwarya, Sani; Rao, J Venkateswara; Tartte, Vijaya

2016-01-01

An endophytic fungal strain isolated from the leaves of Gymnema sylvestre was identified as Pestalotiopsis microspora VJ1/VS1 based on nucleotide sequencing of internal transcribed spacer region (ITS 1-5.8S-ITS 2) of 18S rRNA gene (NCBI accession number KX213894). In this study, an efficient and ecofriendly approach has been reported for the synthesis of silver nanoparticles (AgNPs) using aqueous culture filtrate of P. microspora. Ultraviolet-visible analysis confirmed the synthesis of AgNPs by showing characteristic absorption peak at 435 nm. Fourier transform infrared spectroscopy analysis revealed the presence of phenolic compounds and proteins in the fungal filtrate, which are plausibly involved in the biosynthesis and capping of AgNPs. Transmission electron microscopy (TEM) showed that the AgNPs were spherical in shape of 2–10 nm in size. Selected area electron diffraction and X-ray diffraction studies determined the crystalline nature of AgNPs with face-centered cubic (FCC) lattice phase. Dynamic light scattering analysis showed that the biosynthesized AgNPs possess high negative zeta potential value of −35.7 mV. Biosynthesized AgNPs were proved to be potential antioxidants by showing effective radical scavenging activity against 2,2′-diphenyl-1-picrylhydrazyl and H2O2 radicals with IC50 values of 76.95±2.96 and 94.95±2.18 µg/mL, respectively. The biosynthesized AgNPs exhibited significant cytotoxic effects against B16F10 (mouse melanoma, IC50 =26.43±3.41 µg/mL), SKOV3 (human ovarian carcinoma, IC50 =16.24±2.48 µg/mL), A549 (human lung adenocarcinoma, IC50 =39.83±3.74 µg/mL), and PC3 (human prostate carcinoma, IC50 =27.71±2.89 µg/mL) cells. The biosynthesized AgNPs were found to be biocompatible toward normal cells (Chinese hamster ovary cell line, IC50 =438.53±4.2 µg/mL). Cytological observations on most susceptible SKOV3 cells revealed concentration-dependent apoptotic changes that include cell membrane blebbing, cell shrinkage, pyknotic nuclei, karyorrhexis followed by destructive fragmentation of nuclei. The results together in this study strongly provided a base for the development of potential and versatile biomedical applications of biosynthesized AgNPs in the near future. PMID:27826190

Helichrysum gymnocephalum essential oil: chemical composition and cytotoxic, antimalarial and antioxidant activities, attribution of the activity origin by correlations.

PubMed

Afoulous, Samia; Ferhout, Hicham; Raoelison, Emmanuel Guy; Valentin, Alexis; Moukarzel, Béatrice; Couderc, François; Bouajila, Jalloul

2011-09-29

Helichrysum gymnocephalum essential oil (EO) was prepared by hydrodistillation of its leaves and characterized by GC-MS and quantified by GC-FID. Twenty three compounds were identified. 1,8-Cineole (47.4%), bicyclosesquiphellandrene (5.6%), γ-curcumene (5.6%), α-amorphene (5.1%) and bicyclogermacrene (5%) were the main components. Our results confirmed the important chemical variability of H. gymnocephalum. The essential oil was tested in vitro for cytotoxic (on human breast cancer cells MCF-7), antimalarial (Plasmodium falciparum: FcB1-Columbia strain, chloroquine-resistant) and antioxidant (ABTS and DPPH assays) activities. H. gymnocephalum EO was found to be active against MCF-7 cells, with an IC(50) of 16 ± 2 mg/L. The essential oil was active against P. falciparum (IC(50) = 25 ± 1 mg/L). However, the essential oil exhibited a poor antioxidant activity in the DPPH (IC(50) value > 1,000 mg/L) and ABTS (IC(50) value = 1,487.67 ± 47.70 mg/L) assays. We have reviewed the existing results on the anticancer activity of essential oils on MCF-7 cell line and on their antiplasmodial activity against the P. falciparum. The aim was to establish correlations between the identified compounds and their biological activities (antiplasmodial and anticancer). β-Selinene (R² = 0.76), α-terpinolene (R² = 0.88) and aromadendrene (R² = 0.90) presented a higher relationship with the anti-cancer activity. However, only calamenene (R² = 0.70) showed a significant correlation for the antiplasmodial activity.

Potential of aryl-urea-benzofuranylthiazoles hybrids as multitasking agents in Alzheimer's disease.

PubMed

Kurt, Belma Zengin; Gazioglu, Isil; Basile, Livia; Sonmez, Fatih; Ginex, Tiziana; Kucukislamoglu, Mustafa; Guccione, Salvatore

2015-09-18

New benzofuranylthiazole derivatives containing the aryl-urea moiety were synthesized and evaluated in vitro as dual acetylcholinesterase (AChE)-butyrylcholinesterase (BuChE) inhibitors. In addition, the cupric reducing antioxidant capacities (CUPRAC) and ABTS cation radical scavenging abilities of the synthesized compounds were assayed. The result showed that all the synthesized compounds exhibited inhibitory activity on both AChE and BuChE with 1-(4-(5-bromobenzofuran-2-yl)thiazol-2-yl)-3-(2-fluorophenyl)urea (e25, IC50 value of 3.85 μM) and 1-(4-iodophenyl)-3-(4-(5-nitrobenzofuran-2-yl)thiazol-2-yl)urea (e38, IC50 value of 2.03 μM) as the strongest inhibitors against AChE and BuChE, respectively. Compound e38 was 8.5-fold more potent than galanthamine. The selectivity index of e25 and e38 was 2.40 and 0.37 against AChE and BuChE, respectively. Compound e2, e4 and e11 (IC50 = 0.2, 0.5 and 1.13 μM, respectively) showed a better ABTS cation radical scavenging ability than the standard quercetin (IC50 = 1.18 μM). Best poses of compounds e38 on BuChE and e25 on AChE indicate that the thiazole ring and the amidic moiety are important sites of interaction with both ChEs. In addition, the benzofuran ring and phenyl ring are anchored to the side chains of both enzymes by π-π(pi-pi) interactions. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

The effects of acute pesticide exposure on neuroblastoma cells chronically exposed to diazinon.

PubMed

Axelrad, J C; Howard, C V; McLean, W G

2003-03-14

Speculation about potential neurotoxicity due to chronic exposure to low doses of organophosphate (OP) pesticides is not yet supported by experimental evidence. The objective of this work was to use a cell culture model of chronic OP exposure to determine if such exposure can alter the sensitivity of nerve cells to subsequent acute exposure to OPs or other compounds. NB2a neuroblastoma cells were grown in the presence of 25 microM diazinon for 8 weeks. The OP was then withdrawn and the cells were induced to differentiate in the presence of various other pesticides or herbicides, including OPs and OP-containing formulations. The resulting outgrowth of neurite-like structures was measured by light microscopy and quantitative image analysis and the IC(50) for each OP or formulation was calculated. The IC(50) values in diazinon-pre-exposed cells were compared with the equivalent values in cells not pre-exposed to diazinon. The IC(50) for inhibition of neurite outgrowth by acute application of diazinon, pyrethrum, glyphosate or a commercial formulation of glyphosate was decreased by between 20 and 90% after pre-treatment with diazinon. In contrast, the IC(50) for pirimiphos methyl was unaffected and those for phosmet or chlorpyrifos were increased by between 1.5- and 3-fold. Treatment of cells with chlorpyrifos or with a second glyphosate-containing formulation led to the formation of abnormal neurite-like structures in diazinon-pre-exposed cells. The data support the view that chronic exposure to an OP may reduce the threshold for toxicity of some, but by no means all, environmental agents.

Design, synthesis and antileishmanial in vitro activity of new series of chalcones-like compounds: a molecular hybridization approach.

PubMed

Barbosa, Ticiano P; Sousa, Suervy C O; Amorim, Francianne M; Rodrigues, Yara K S; de Assis, Priscilla A C; Caldas, John P A; Oliveira, Márcia R; Vasconcellos, Mário L A A

2011-07-15

The chalcone-like series 1a-1g was efficiently synthesized from Morita-Baylis-Hillman reaction (52-74% yields). Compounds 1a-1g were designed by molecular hybridization based on the anti-inflammatory drug methyl salicylate (3) and the antileishmanial moiety of the Morita-Baylis-Hillman adducts 2a-2g. The 1a-1g compounds were much more actives than precursor series 2a-2g, for example, IC(50)=7.65 μM on Leishmania amazonensis and 10.14 μM on Leishmania chagasi (compound 1c) when compared to IC(50)=50.08 μM on L. amazonensis and 82.29 μM on L. chagasi (compound 2c). The IC(50) values of compound 3 (228.49 μM on L. amazonensis and 261.45 μM on L. chagasi) and acryloyl salicylate 4 (108.50 μM on L. amazonensis and 118.83 μM on L. chagasi) were determined here, by the first time, on Leishmania. Copyright © 2011 Elsevier Ltd. All rights reserved.

Selective labeling of serotonin receptors by d-[3H]lysergic acid diethylamide in calf caudate.

PubMed Central

Whitaker, P M; Seeman, P

1978-01-01

Since it was known that d-lysergic acid diethylamide (LSD) affected catecholaminergic as well as serotoninergic neurons, the objective in this study was to enhance the selectivity of [3H]LSD binding to serotonin receptors in vitro by using crude homogenates of calf caudate. In the presence of a combination of 50 nM each of phentolamine (added to preclude the binding of [3H]LSD to alpha-adrenoceptors), apomorphine, and spiperone (added to preclude the binding of [3H]LSD to dopamine receptors), it was found by Scatchard analysis that the total number of [3H]LSD sites went down to 300 fmol/mg, compared to 1100 fmol/mg in the absence of the catecholamine-blocking drugs. The IC50 values (concentrations to inhibit binding by 50%) for various drugs were tested on the binding of [3H]LSD in the presence of 50 nM each of apomorphine (A), phentolamine (P) and spiperone (S). With this combination, the IC50 for serotonin was 35 nM (compared to 1000 nM without it), indicating that [3H]LSD had become considerably more selectively displaceable by serotonin under these conditions whereas the effects of norepinephrine and dopamine on [3H]LSD binding were eliminated. Various ergots had approximately equal IC50 values against [3H]serotonin and [3H]LSD but tryptamines were much more selective against [3H]serotonin; the data may indicate the existence of the two types of serotonin receptors. PMID:32537

Cytotoxic activity of quassinoids from Eurycoma longifolia.

PubMed

Miyake, Katsunori; Li, Feng; Tezuka, Yasuhiro; Awale, Suresh; Kadota, Shigetoshi

2010-07-01

Twenty-four quassinoids isolated from Eurycoma longifolia Jack were investigated for their cytotoxicity against a panel of four different cancer cell lines, which includes three murine cell lines [colon 26-L5 carcinoma (colon 26-L5), B16-BL6 melanoma (B16-BL6), Lewis lung carcinoma (LLC)] and a human lung A549 adenocarcinoma (A549) cell line. Among the tested compounds, eurycomalactone (9) displayed the most potent activity against all the tested cell lines; colon 26-L5 (IC50 = 0.70 microM), B16-BL6 (IC50 = 0.59 microM), LLC (IC50 = 0.78 microM), and A549 (IC50 = 0.73 microM). These activities were comparable to clinically used anticancer agent doxorubicin (colon 26-L5, IC50 = 0.76 microM; B16-BL6, IC50 = 0.86 microM; LLC, IC50 = 0.80 microM; A549, IC50 = 0.66 microM).

In vitro antioxidant, anti-inflammatory and anticancer activities of ethyl acetate soluble proanthocyanidins of the inflorescence of Cocos nucifera L.

PubMed

Padumadasa, Chayanika; Dharmadana, Durga; Abeysekera, Ajit; Thammitiyagodage, Mayuri

2016-09-05

Proanthocyanidins belong to a class of polyphenolic compounds called flavonoids and have been reported to exhibit important biological activities. The immature inflorescence of Cocos nucifera L. is used by Ayurvedic and traditional medical practitioners for the treatment of menorrhagia in Sri Lanka. Our studies have shown that the inflorescence of Cocos nucifera L. predominantly contains proanthocyanidins. To determine the antioxidant, anti-inflammatory and anticancer activities of ethyl acetate soluble proanthocyanidins (EASPA) of immature inflorescence of Cocos nucifera L. EASPA fraction of an acetone/water (7:3) extract of Cocos nucifera L. inflorescence was purified on Sephadex LH-20 and was used for the study. Antioxidant activity of EASPA was determined using DPPH and SOR scavenging assays. Anti-inflammatory activity of EASPA was determined by oxidative burst assay using chemiluminescence technique. MTT colorimetric assay was used to evaluate the cytotoxicity of EASPA to both PC3 and HeLa cells. EASPA showed radical scavenging activity against both DPPH and superoxide radicals with IC50 values of 11.02 ± 0.60 μg/mL and 26.11 ± 0.72 μg/mL. In both assays, EASPA showed less antioxidant activity than the standards used. It exhibited similar anti-inflammatory activity (IC50 = 10.31 ± 1.11 μg/mL) to ibuprofen (IC50 = 11.20 ± 1.90 μg/mL) (P ≥ 0.05). EASPA also showed stronger cytotoxic activity towards Hela cells (IC50 = 18.78 ± 0.90 μg/mL) than tamoxifen (IC50 = 28.80 ± 1.94 μg/mL) (P ≤ 0.05), while low cytotoxicity was observed against PC3 cells (IC50 = 44.21 ± 0.73 μg/mL) compared to doxorubicin (IC50 = 1.38 ± 0.16 μg/mL). EASPA showed antioxidant, anti-inflammatory and anticancer activities.

Robust Sub-nanomolar Library Preparation for High Throughput Next Generation Sequencing.

PubMed

Wu, Wells W; Phue, Je-Nie; Lee, Chun-Ting; Lin, Changyi; Xu, Lai; Wang, Rong; Zhang, Yaqin; Shen, Rong-Fong

2018-05-04

Current library preparation protocols for Illumina HiSeq and MiSeq DNA sequencers require ≥2 nM initial library for subsequent loading of denatured cDNA onto flow cells. Such amounts are not always attainable from samples having a relatively low DNA or RNA input; or those for which a limited number of PCR amplification cycles is preferred (less PCR bias and/or more even coverage). A well-tested sub-nanomolar library preparation protocol for Illumina sequencers has however not been reported. The aim of this study is to provide a much needed working protocol for sub-nanomolar libraries to achieve outcomes as informative as those obtained with the higher library input (≥ 2 nM) recommended by Illumina's protocols. Extensive studies were conducted to validate a robust sub-nanomolar (initial library of 100 pM) protocol using PhiX DNA (as a control), genomic DNA (Bordetella bronchiseptica and microbial mock community B for 16S rRNA gene sequencing), messenger RNA, microRNA, and other small noncoding RNA samples. The utility of our protocol was further explored for PhiX library concentrations as low as 25 pM, which generated only slightly fewer than 50% of the reads achieved under the standard Illumina protocol starting with > 2 nM. A sub-nanomolar library preparation protocol (100 pM) could generate next generation sequencing (NGS) results as robust as the standard Illumina protocol. Following the sub-nanomolar protocol, libraries with initial concentrations as low as 25 pM could also be sequenced to yield satisfactory and reproducible sequencing results.

Cytotoxic constituents of Pachyrhizus tuberosus from Peruvian amazon.

PubMed

Leuner, Olga; Havlik, Jaroslav; Budesinsky, Milos; Vrkoslav, Vladimir; Chu, Jessica; Bradshaw, Tracey D; Hummelova, Jana; Miksatkova, Petra; Lapcik, Oldrich; Valterova, Irena; Kokoska, Ladislav

2013-10-01

Investigations into the chemical constituents of the seeds of the neglected tuber crop Pachyrhizus tuberosus (Leguminosae) resulted in the isolation of seven components: five rotenoids [12a-hydroxyerosone (1), 12a-hydroxydolineone (2), erosone (3), 12a-hydroxyrotenone (4) and rotenone (6)], a phenylfuranocoumarin [pachyrrhizine (5)] and an isoflavanone [neotenone (7)]. The compounds were isolated using several chromatography techniques and characterized and verified by NMR and HPLC/MS. The MTT assay was used to examine the selective cytotoxic effects of the methanolic P. tuberosus extract and isolated compounds in two human cancer cell lines [breast (MCF-7) and colorectal (HCT-116)] and in non-transformed human fibroblasts (MRC-5); IC50 values were calculated. The methanolic P. tuberosus extract displayed respectable cytotoxic effects against HCT-116 and MCF-7 cells with IC50 values of 7.3 and 6.3 microg/mL, respectively. Of the compounds, 6 exacted greatest cytotoxicity and selectivity towards the cancer cell lines tested, yielding IC50 values of 0.3 microg/mL against both MCF-7 and HCT-116 cells, and a 6-fold reduced activity against MRC-5 fibroblasts. Compound 4 also demonstrated cytotoxicity against MCF-7 and HCT-116 (1.1 and 1.8 microg/mL, respectively), and reduced cytotoxicity towards MRC-5 cells (7.5 mirog/mL). The results revealed from the in vitro cytotoxic MTT assay are worthy of further antitumor investigation.

Risk assessment of drug-drug interactions using hepatocytes suspended in serum during the drug discovery process.

PubMed

Kosugi, Yohei; Hirabayashi, Hideki; Igari, Tomoko; Fujioka, Yasushi; Okuda, Teruaki; Moriwaki, Toshiya

2014-04-01

1. This study optimized the reported approach for the prediction of drug-drug interactions (DDIs) using hepatocytes suspended in serum (HHSS) and provided a practical usage of HHSS in the early and late phases of drug discovery. 2. First, the IC50 was determined using HHSS and evaluated as a qualitative index for DDI risks in the early phase. A retrospective study on clinical DDI cases revealed that inhibitors with IC50 < 100 μmol/L caused clinical DDIs while those with IC50 > 100 μmol/L showed weak or no potential for DDIs. Meanwhile, a pragmatic cutoff value could not be determined using previously reported Ki values of recombinant human cytochrome P450s. 3. Second, for a more substantial DDI risk assessment in the later phase, quantitative predictions of clinical DDI based on a static model were attempted by optimizing the most appropriate inhibitor concentration ([I]). The use of hepatic input plasma concentrations as a surrogate for [I] achieved the most successful predictions of the magnitude of increase in the AUC (within a 2-fold range of the observed values for 93.8% of inhibitors). 4. Through this study, we proposed the practical application of HHSS for an effective workflow to explore and profile candidates with less DDI liability.

Inhibitory Effect of Crizotinib on Creatinine Uptake by Renal Secretory Transporter OCT2.

PubMed

Arakawa, Hiroshi; Omote, Saki; Tamai, Ikumi

2017-09-01

Crizotinib, a tyrosine kinase inhibitor, exhibits some cases of an increase in serum creatinine levels. Creatinine is excreted by not only glomerular filtration but also active secretion by organic cation transporters such as organic cation transporter 2 (OCT2). In the present study, we evaluated in vitro inhibitory effect of crizotinib on OCT2 by directly measuring creatinine uptake by OCT2. Coincubation of crizotinib reduced uptake of [ 14 C]creatinine by cultured HEK293 cells expressing OCT2 (HEK293/OCT2) in a concentration-dependent manner with IC 50 values of 1.58 ± 0.24 μM. Preincubation or both preincubation and coincubation (preincubation/coincubation) with crizotinib showed stronger inhibitory effect on [ 14 C]creatinine uptake compared with that in coincubation alone with IC 50 values of 0.499 ± 0.076 and 0.347 ± 0.040 μM, respectively. These IC 50 values of crizotinib on [ 3 H]N-methyl-4-phenylpyridinium acetate uptake by OCT2 were 10-20 times higher than those of [ 14 C]creatinine uptake. Furthermore, preincubation of crizotinib inhibited creatinine uptake by OCT2 in an apparently competitive manner. In conclusion, crizotinib at a clinically relevant concentration has the potential to inhibit creatinine transport by OCT2, suggesting an increase of serum creatinine levels in clinical use. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Enhancing the efficiency of bortezomib conjugated to pegylated gold nanoparticles: an in vitro study on human pancreatic cancer cells and adenocarcinoma human lung alveolar basal epithelial cells.

PubMed

Coelho, Sílvia Castro; Almeida, Gabriela M; Santos-Silva, Filipe; Pereira, Maria Carmo; Coelho, Manuel A N

2016-08-01

Gold nanoparticles have become promising vectors for cancer diagnosis and treatment. The present study investigates the effect of bortezomib (BTZ), a proteasome inhibitor, conjugated with pegylated gold nanoparticles (PEGAuNPs) in pancreatic and lung cancer cells. Synthesized gold nanoparticles (PEGAuNPs) were conjugated with bortezomib antitumor drug. We investigated the cytotoxicity induced by BTZ conjugated with functionalized gold nanoparticles in vitro, in the human pancreatic (S2-013) and lung (A549) cancer cell lines. We found an efficient of conjugation of BTZ with PEGAuNPs. In vitro assays showed that after 72 h' incubation with PEGAuNPs-BTZ cancer cells revealed alterations in morphology; also for S2-013 and A549 cancer cells, the IC50 value of free BTZ is respectively 1.5 and 4.3 times higher than the IC50 value of PEGAuNPs-BTZ. Furthermore, for TERT-HPNE, the IC50 value is around 63 times lower for free BTZ than the conjugated nanovehicle. Cell growth inhibition results showed a remarkable enhancement in the effect of BTZ when conjugated with AuNPs. Our findings showed that conjugation with PEGAuNPs enhance the BTZ growth-inhibition effect on human cancer cells (S2-013 and A549) and decreases its toxicity against normal cells (TERT-HPNE).

QSAR models for thiophene and imidazopyridine derivatives inhibitors of the Polo-Like Kinase 1.

PubMed

Comelli, Nieves C; Duchowicz, Pablo R; Castro, Eduardo A

2014-10-01

The inhibitory activity of 103 thiophene and 33 imidazopyridine derivatives against Polo-Like Kinase 1 (PLK1) expressed as pIC50 (-logIC50) was predicted by QSAR modeling. Multivariate linear regression (MLR) was employed to model the relationship between 0D and 3D molecular descriptors and biological activities of molecules using the replacement method (MR) as variable selection tool. The 136 compounds were separated into several training and test sets. Two splitting approaches, distribution of biological data and structural diversity, and the statistical experimental design procedure D-optimal distance were applied to the dataset. The significance of the training set models was confirmed by statistically higher values of the internal leave one out cross-validated coefficient of determination (Q2) and external predictive coefficient of determination for the test set (Rtest2). The model developed from a training set, obtained with the D-optimal distance protocol and using 3D descriptor space along with activity values, separated chemical features that allowed to distinguish high and low pIC50 values reasonably well. Then, we verified that such model was sufficient to reliably and accurately predict the activity of external diverse structures. The model robustness was properly characterized by means of standard procedures and their applicability domain (AD) was analyzed by leverage method. Copyright © 2014 Elsevier B.V. All rights reserved.

Phytochemicals and antidiabetic activity of Eusideroxylon zwageri stem bark collected from East Kalimantan, Indonesia

NASA Astrophysics Data System (ADS)

Kusuma, I. W.; Rahmini; Ramadhan, R.; Rahmawati, N.; Suwasono, R. A.; Sari, NM

2018-04-01

Eusideroxylon zwagery (Lauraceae), a tropical tree species known as ulin or borneo iron wood and traditionally used for the treatment of diabetes in the Ethnic of Kutai. Plant extract was prepared by maceration using ethanol. The plant extract was evaluated its DPPH and superoxide radicals scavenging activity, the inhibition on α-glucosidase and α-amylase activity as antidiabetic potential and the analysis of the total phenolic, total flavonoids and proanthocyanidin contents. The ethanolic extract of the stem bark was 8.62% on the dry weight basis. The IC50 values of antioxidant activity of the extract in DPPH and superoxide radical scavenging mechanisms were 44.90 µg/ml and 30.47 µg/ml. In antidiabetic assay, the E. zwageri stem bark extract showed IC50 value 58.45µg/ml in ɑ-glucosidase inhibition, and 9.04 µg/ml in ɑ-amylase inhibition. Quercetin, an antidiabetic activity-having flavonoid, displayed IC50 values 2.00 µg/ml and 4.04 µg/ml in ɑ-glucosidase and ɑ-amylase inhibitory assays. In phytochemical assay, the extract had 31.28 GAE/g extract (mg), 30.48 CE/g extract (mg) and 183.3 PE/g extract (mg) for the total phenolic, total flavonoid and total proanthocyanidin contents. The limited reports of E. zwageri indicated the needs to search the active compounds from plant as potential antidiabetic agents by considering plant conservation status.

The antiparasitic isoxazoline A1443 is a potent blocker of insect ligand-gated chloride channels.

PubMed

Ozoe, Yoshihisa; Asahi, Miho; Ozoe, Fumiyo; Nakahira, Kunimitsu; Mita, Takeshi

2010-01-01

A structurally unique isoxazoline class compound, A1443, exhibits antiparasitic activity against cat fleas and dog ticks comparable to that of the commercial ectoparasiticide fipronil. This isoxazoline compound inhibits specific binding of the gamma-aminobutyric acid (GABA) receptor channel blocker [(3)H]4'-ethynyl-4-n-propylbicycloorthobenzoate (EBOB) to housefly-head membranes, with an IC(50) value of 455pM. In contrast, the IC(50) value in rat-brain membranes is>10muM. To study the mode of action of this isoxazoline, we utilized MdGBCl and MdGluCl cDNAs, which encode the subunits of housefly GABA- and glutamate-gated chloride channels, respectively. Two-electrode voltage clamp electrophysiology was used to confirm that A1443 blocks GABA- and glutamate-induced chloride currents in Xenopus oocytes expressing MdGBCl or MdGluCl channels, with IC(50) values of 5.32 and 79.9 nM, respectively. Blockade by A1443 was observed in A2'S-MdGBCl and S2'A-MdGluCl mutant channels at levels similar to those of the respective wild-types, and houseflies expressing A2'S-MdGBCl channels were as susceptible to A1443 as standard houseflies. These findings indicate that A1443 is a novel and specific blocker of insect ligand-gated chloride channels. Copyright 2009 Elsevier Inc. All rights reserved.

Inhibition of chemiluminescence and chemotactic activity of phagocytes in vitro by the extracts of selected medicinal plants.

PubMed

Jantan, Ibrahim; Harun, Nurul Hikmah; Septama, Abdi Wira; Murad, Shahnaz; Mesaik, M A

2011-04-01

The methanol extracts of 20 selected medicinal plants were investigated for their effects on the respiratory burst of human whole blood, isolated human polymorphonuclear leukocytes (PMNs) and isolated mice macrophages using a luminol/lucigenin-based chemiluminescence assay. We also tested the effect of the extracts on chemotactic migration of PMNs using the Boyden chamber technique. The extracts of Curcuma domestica L., Phyllanthus amarus Schum & Thonn and C. xanthorrhiza Roxb. were the samples producing the strongest oxidative burst of PMNs with luminol-based chemiluminescence, with IC(50) values ranging from 0.5 to 0.7 μg/ml. For macrophage cells, the extracts which showed strong suppressive activity for luminol-based chemiluminescence were C. xanthorrhiza and Garcinia mangostana L. Among the extracts studied, C. mangga Valton & Vazsjip, Piper nigrum L. and Labisia pumila var. alata showed strong inhibitory activity on lucigenin-amplified oxidative burst of PMNs, with IC(50) values ranging from 0.9 to 1.5 μg/ml. The extracts of Zingiber officinale Rosc., Alpinia galangal (L.) Willd and Averrhoa bilimbi Linn showed strong inhibition on the chemotaxic migration of cells, with IC(50) values comparable to that of ibuprofen (1.5 μg/ml). The results suggest that some of these plants were able to modulate the innate immune response of phagocytes at different steps, emphasizing their potential as a source of new immunomodulatory agents.

Syntheses, cholinesterases inhibition, and molecular docking studies of pyrido[2,3-b]pyrazine derivatives.

PubMed

Hameed, Abdul; Zehra, Syeda T; Shah, Syed J A; Khan, Khalid M; Alharthy, Rima D; Furtmann, Norbert; Bajorath, Jürgen; Tahir, Muhammad N; Iqbal, Jamshed

2015-11-01

Cholinesterases, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), have a role in cholinergic deficit which evidently leads to Alzheimer's disease (AD). Inhibition of cholinesterases with small molecules is an attractive strategy in AD therapy. This study demonstrates synthesis of pyrido[2,3-b]pyrazines (6a-6q) series, their inhibitory activities against both cholinesterases, AChE and BChE, and molecular docking studies. The bioactivities data of pyrido[2,3-b]pyrazines showed 3-(3'-nitrophenyl)pyrido[2,3-b]pyrazine 6n a potent dual inhibitor among the series against both AChE and BChE with IC50 values of 0.466 ± 0.121 and 1.89 ± 0.05 μm, respectively. The analogues 3-(3'-methylphenyl)pyrido[2,3-b]pyrazine 6c and 3-(3'-fluorophenyl)pyrido[2,3-b]pyrazine 6f were found to be selective inhibition for BChE with IC50 values of 0.583 ± 0.052 μm and AChE with IC50 value of 0.899 ± 0.10 μm, respectively. Molecular docking studies of the active compounds suggested the putative binding modes with cholinesterases. The potent compounds among the series could potentially serves as good leads for the development of new cholinesterase inhibitors. © 2015 John Wiley & Sons A/S.

Synthesis and anti-tumor evaluation of panaxadiol halogen-derivatives.

PubMed

Xiao, Shengnan; Chen, Shuai; Sun, Yuanyuan; Zhou, Wuxi; Piao, Huri; Zhao, Yuqing

2017-09-01

In the current work, 13 novel panaxadiol (PD) derivatives were synthesized by reacting with chloroacetyl chloride and bromoacetyl bromide. Their in vitro antitumor activities were evaluated on three human tumor cell lines (HCT-116, BGC-823, SW-480) and three normal cells (human gastric epithelial cell line-GES-1, hair follicle dermal papilla cell line-HHDPC and rat myocardial cell line-H9C2) by MTT assay. Compared with PD, the results demonstrated that compound 1e, 2d, 2e showed significant anti-tumor activity against three tumor cell lines, the IC50 value of compound 2d against HCT-116 was the lowest (3.836μM). The anti-tumor activity of open-ring compounds are significantly better than the compounds of C-25 cyclization. Compound 1f, 2f, 2g showed the strong anti-tumor activity. The IC50 value of compound 2g against BGC-823 and SW-480 were the lowest (0.6μM and 0.1μM, respectively). Combined with cytotoxicity test, the IC50 value of compound 1e, 2d, 2e are greater than 100. the open-ring compounds (1f, 2f, 2g) showed a strong toxicity. The toxicity of 1f is lower than 2f and 2g. These compounds may be useful for the development of novel antiproliferative agents. Copyright © 2017. Published by Elsevier Ltd.

Evaluation of neuraminidase enzyme assays using different substrates to measure susceptibility of influenza virus clinical isolates to neuraminidase inhibitors: report of the neuraminidase inhibitor susceptibility network.

PubMed

Wetherall, N T; Trivedi, T; Zeller, J; Hodges-Savola, C; McKimm-Breschkin, J L; Zambon, M; Hayden, F G

2003-02-01

The increasing use of influenza virus neuraminidase (NA) inhibitors (NIs) necessitates the development of reliable methods for assessing the NI susceptibility of clinical isolates. We evaluated three NA inhibition assays against a panel of five clinical isolates each of influenza virus A/H1N1, A/H3N2, and B strains and four viruses with a defined resistance genotype (R292K, H274Y, R152K, and E119V). For fluorometric enzyme assay (FA) 1 (FA-1), 2'-(4-methylumbelliferyl)-alpha-D-N-acetylneuraminic acid (MUNANA) at 100 microM was used as the substrate, with pretitration of the virus input. For FA-2, MUNANA at 200 microM was used as the substrate, with a fixed 1:10 dilution of input virus. For the chemiluminescence (CL) assay, the 1,2-dioxetane derivative of sialic acid at 100 microM was used as the substrate, with pretitration of the virus. Four different operators repeated the assays several times in a blinded fashion with both zanamivir and oseltamivir carboxylate (GS4071) to determine intra- and interassay variations. Mean 50% inhibitory concentration (IC(50)) values were lower and generally less variable with the CL assay. FA-1 displayed greater variation than the CL assay or FA-2 and the highest IC(50) values with zanamivir; FA-2 showed the highest values with oseltamivir, particularly for influenza virus B, and was more variable with zanamivir than was the CL assay. All three assays detected 40-fold or greater changes in IC(50) values for the resistant viruses with at least one drug. Mixing experiments, whereby increasing fractions (0, 20, 40, 60, 80, and 100%) of NA from a known NI-resistant virus were mixed with the corresponding NI-sensitive parental NA, indicated that the resolution of IC(50) values was clearer with the CL assay than with FA-2 for two of the resistant variants (R152K and E119V). The FA and CL methods were reliable for the detection of NI resistance, but all assays have certain limitations. Based on reproducibility, ease of automation, time required for the assay, and greater sensitivity, the CL assay was selected for future susceptibility testing of influenza virus isolates circulating globally.

Anti-inflammatory and cytotoxic neoflavonoids and benzofurans from Pterocarpus santalinus.

PubMed

Wu, Shou-Fang; Chang, Fang-Rong; Wang, Sheng-Yang; Hwang, Tsong-Long; Lee, Chia-Lin; Chen, Shu-Li; Wu, Chin-Chung; Wu, Yang-Chang

2011-05-27

Five new benzofurans, pterolinuses A-E (1-5), six new neoflavonoids, pterolinuses F-J (8-13), and five known compounds (6, 7, 14-16) were isolated from an extract of Pterocarpus santalinus heartwood. All new structures were elucidated by spectroscopic methods, and configurations were confirmed by CD spectral data and optical rotation values. The isolates were evaluated for anti-inflammatory and cytotoxic activities. Six compounds (1, 2, 4, 6, 7, and 15) showed significant inhibition in at least one anti-inflammatory assay. Compound 2 showed the best selective effect against superoxide anion generation in human neutrophils with, an IC50 value of 0.19 μg/mL, and was 6.2-fold more potent than the positive control LY294002. Compound 14 showed the highest cytotoxicity against Ca9-22 cancer cells, with an IC50 value of 0.46 μg/mL.

Antiviral effects of Curcuma longa L. against dengue virus in vitro and in vivo

NASA Astrophysics Data System (ADS)

Ichsyani, M.; Ridhanya, A.; Risanti, M.; Desti, H.; Ceria, R.; Putri, D. H.; Sudiro, T. M.; Dewi, B. E.

2017-12-01

Dengue is the most common infective disease caused by dengue virus (DENV) and endemic diseases in tropical and subtropical areas. Until now, there is no specific antiviral for dengue infection. It is known that viral load is related to disease severity. Curcuma longa L. (turmeric) with curcumin as major active compound has been identified for its antiviral effect. This study to determine antiviral effect of C. longa extract on DENV-2 in vitro and in vivo along with its toxicity in liver and kidney of ddY mice. Antiviral activity (IC50) and toxicity (CC50) in vitro was examined on Huh7it-1 cells by focus assay and a MTT assay, respectively. To determine the selectivity index (SI), we used CC50 and IC50 value. The safe doses obtained were used for toxicity tests of liver and kidney with histopathological and biochemical observations. The C. longa extracts was given orally with dose of 0.147 mg/mL for each mice at 2 hours after injected with DENV-2 infected Huh7it-1 cells. Serum was collected from intraorbital at 6 hours and 24 hours after infection and focus assay was used to determine viral load. In this study, the acquired value of IC50 was 17,91 μg/mL whereas the value of CC50 was 85,4 μg/mL. The value of SI of C. longa was 4.8. In vivo, we found that C. longa remarkable reduced of viral load after 24 hour. Histopathological examination showed no specific abnormalities in liver and kidney. There was no significant increase in levels of SGPT, SGOT, urea, and creatinine. From this study it can be concluded that C. longa could potentially be used as antiviral against DENV with low cytotoxicity and effective inhibition.

Synthesis of 7-hydroxy-4'-methoxyflavanone and 7-hydroxy-4'-methoxyflavone as a candidate anticancer against cervical (HeLa) cancer cell and colon (WiDr) cancer cell by in vitro

NASA Astrophysics Data System (ADS)

Matsjeh, Sabirin; Anwar, Chairil; Solikhah, Eti Nurwening; Farah, Harra Ismi; Nurfitria, Kurnia

2017-03-01

The compound 7-hydroxy-4'-methoxyflavanone and 7-hydroxy-4'-methoxyflavone have been synthesized through cyclization reaction of 2 ', 4'-dihydroxy-4-methoxychalcone (1,3-diphenyl-2-propene-1-one). The 2 ', 4'-dihydroxy-4-methoxychalcone were synthesized through Claisen-Schmidt condensation from 2,4-dihydroxyacetophenone and 4-methoxybenzaldehyde (anisaldehyde) in aqueous KOH as a catalyst in ethanol. The 7-hydroxy-4'-methoxyflavanone has been synthesized through cyclization reaction of 2 ', 4'-dihydroxy-4-methoxychalcone by Oxa-Michael addition reaction with sulfuric acid as a catalyst in ethanol. The 7-hydroxy-4'-methoxyflavone has been synthesized through oxidative cyclization reaction of 2 ', 4'-dihydroxy-4-methoxychalcone using I2 in DMSO as a catalyst with a mole ratio (1: 1) mol. All these producets were characterized by FT-IR, GC-MS, and 1H-NMR and 13C-NMR spectrometer. Both of these compounds were tested citotoxycity activity as an anticancer against cervical and colon cancer cells (HeLa and WiDr cell lines) using MTT assay in vitro. Dose series given test solution concentration on HeLa and WiDr cells starting from 0,78; 1,56; 3,12; 6,25; 12,50; 25; 50 and 100 µg/mL with a long incubation treatment for 24 hours. The results study showed that the 7-hydroxy-4'-methoxyflavanone as bright yellow crystals with a melting point 172-174 ° C and a yield of 56.67% and the 7-hydroxy-4'-methoxyflavone as bright yellow crystals with a yield of 88, 31%, and a melting point of 263-265 ° C. The test results cytotoxic 7-hydroxy-4-methoxyflavone showed active against HeLa cells with IC50 value of 25.73 µg/mL and was quite active in the WiDr cells with IC50 value of 83.75 µg/mL. The result of the activity of 7-hydroxy-4-methoxyflavanone show active cytotoxic activity against HeLa and WiDr cell growth with IC50 value of 40.13 µg/mL and 37.85 µg/mL. IC50 value indicated that 7-hydroxy-4'-methoxyflavone and 7-hydroxy-4'-methoxyflavanone potential as inhibitors in HeLa and WiDr. cells

New isochaetochromin, an inhibitor of triacylglycerol synthesis in mammalian cells, produced by Penicillium sp. FKI-4942: I. Taxonomy, fermentation, isolation and biological properties.

PubMed

Ugaki, Narihiro; Matsuda, Daisuke; Yamazaki, Hiroyuki; Nonaka, Kenichi; Masuma, Rokuro; Omura, Satoshi; Tomoda, Hiroshi

2012-01-01

A new bis-naphtho-γ-pyrone isomer named isochaetochromin A(1) was isolated along with known isochaetochromins B(1) and B(2) from the culture broth of Penicillium sp. FKI-4942 by solvent extraction, silica gel column chromatography and HPLC. Among them, isochaetochromin B(1) showed the most potent inhibitory activity of triacylglycerol synthesis with an IC(50) value of 5.6 μM, followed by isochaetochromins B(2) (IC(50), 11 μM) and A(1) (33 μM).

Chemical constituents from rhizome of Anemone amurensis.

PubMed

Lv, Chong-Ning; Li, Yan-Jiao; Wang, Jing; Qin, Ru-Lan; Lei, Tian-Li; Lu, Jin-Cai

2016-07-01

Phytochemical investigation of the 70% EtOH extract of the rhizome of Anemone amurensis led to the isolation of two new oleanane-type triterpenoid saponins 1 and 2. Their structures were elucidated on the basis of chemical and spectral analysis, including 1D, 2D NMR data, and HR-ESI-MS. Compounds 1 and 2 were tested for cytotoxicities against two human cancer cell lines (A549 and Hep-G2). Compound 2 showed potent cytotoxicity with IC50 values of 38.53 and 66.17 μM, respectively, while compound 1 with IC50 > 100 μM.

Synthesis of (benzimidazol-2-yl)aniline derivatives as glycogen phosphorylase inhibitors.

PubMed

Galal, Shadia A; Khattab, Muhammad; Andreadaki, Fotini; Chrysina, Evangelia D; Praly, Jean-Pierre; Ragab, Fatma A F; El Diwani, Hoda I

2016-11-01

A series of (benzimidazol-2-yl)-aniline (1) derivatives has been synthesized and evaluated as glycogen phosphorylase (GP) inhibitors. Kinetics studies revealed that compounds displaying a lateral heterocyclic residue with several heteroatoms (series 3 and 5) exhibited modest inhibitory properties with IC 50 values in the 400-600μM range. Arylsulfonyl derivatives 7 (Ar: phenyl) and 9 (Ar: o-nitrophenyl) of 1 exhibited the highest activity (series 2) among the studied compounds (IC 50 324μM and 357μM, respectively) with stronger effect than the p-tolyl analogue 8. Copyright © 2016 Elsevier Ltd. All rights reserved.

New Labdane-Type Diterpenoids and Anti-Inflammatory Constituents from Hedychium coronarium

PubMed Central

Chen, Jih-Jung; Ting, Chia-Wei; Wu, Yi-Chin; Hwang, Tsong-Long; Cheng, Ming-Jen; Sung, Ping-Jyun; Wang, Tai-Chi; Chen, Jinn-Fen

2013-01-01

Four new labdane-type diterpenoids: hedychicoronarin (1), peroxycoronarin D (2), 7β-hydroxycalcaratarin A (3), and (E)-7β-hydroxy-6-oxo-labda-8(17),12-diene-15,16-dial (4), have been isolated from the rhizomes of Hedychium coronarium, together with 13 known compounds (5–17). The structures of these new compounds were determined through spectroscopic and MS analyses. Compounds 3, 5, 6, and 10 exhibited inhibition (IC50 values ≤4.52 μg/mL) of superoxide anion generation by human neutrophils in response to formyl-L-methionyl-L-leucyl-L-phenylalanine/cytochalasin B (fMLP/CB). Compounds 3–6, 10, and 11 inhibited fMLP/CB-induced elastase release with IC50 values ≤6.17 μg/mL. PMID:23799360

Flavonoid alkaloids from Scutellaria moniliorrhiza with anti-inflammatory activities and inhibitory activities against aldose reductase.

PubMed

Han, Qing-Tong; Ren, Yan; Li, Gui-Sheng; Xiang, Kang-Lin; Dai, Sheng-Jun

2018-05-11

Four undescribed flavonoid alkaloids, as two pairs of enantiomers, were initially isolated as a racemate from the whole plant of Scutellaria moniliorrhiza. By means of chiral HPLC, four isomers, named scumonilines A-D, were successfully separated, and their chemical structures including absolute configurations were established by mass as well as NMR spectroscopy and CD technique. In vitro, four flavonoid alkaloids showed anti-inflammatory activities, with IC 50 values against the release of β-glucuronidase from polymorphonuclear leukocytes of rats being in the range 5.16-5.85 μΜ. Moreover, four compounds were evaluated for their inhibitory activities against aldose reductase, and gave IC 50 values in the range 2.29-3.03 μΜ. Copyright © 2018 Elsevier Ltd. All rights reserved.

New isochromophilones VII and VIII produced by Penicillium sp. FO-4164.

PubMed

Yang, D J; Tomoda, H; Tabata, N; Masuma, R; Omura, S

1996-03-01

New isochromophilones VII and VIII were isolated from the culture broth of Penicillium sp. FO-4164. The structures were elucidated as 6H-2-benzopyran-6,8(7H)-dione, 5-chloro-3-(3',5'-dimethyl-1',3'-heptadienyl)-1,7,8a-trihydro-7, 8a-dihydroxy-7-methyl-7-acetate for isochromophilone VII and 6H-2-benzopyran-6-one,5-chloro-3-(3',5'-dimethyl-1', 3'-heptadienyl)-1,7,8,8a-tetrahydro-7,8-dihydroxy-7-methyl-8-acetate for isochromophilone VIII. Isochromophilones VII and VIII inhibited diacylglycerol acyltransferase activity with IC50 values of 20.0 and 127 microM and acyl-CoA: cholesterol acyltransferase activity with IC50 values of 24.5 and 47.0 microM, respectively.

Cholinesterase inhibitors from Cleistocalyx operculatus buds.

PubMed

Min, Byung Sun; Cuong, To Dao; Lee, Joo-Sang; Shin, Beom-Soo; Woo, Mi Hee; Hung, Tran Manh

2010-10-01

Five flavonoids, myricetin-3'-methylether 3-O-β-D: -galactopyranoside (1), myricetin-3',5'-dimethylether 3-O-β-D: -galactopyranoside (2), quercetin (3), kaempferol (4), and tamarixetin (5) were isolated from the buds of Cleistocalyx operculatus (Myrtaceae). The chemical structures of these compounds were determined on the basis of spectroscopic analyses, including 2D NMR. Their anti-Alzheimer effects were evaluated via acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity assays. All five compounds 1-5 showed potential inhibitory activities against AChE with IC(50) values of 19.9, 37.8, 25.9, 30.4 and 22.3 μM, respectively, while compounds 1, 3, 4 and 5 also possessed BChE inhibitory activity with IC(50) values of 152.5, 177.8, 62.5, and 160.6 μM, respectively.

Amides and neolignans from the aerial parts of Piper bonii.

PubMed

Ding, Duo-Duo; Wang, Yue-Hu; Chen, Ya-Hui; Mei, Ren-Qiang; Yang, Jun; Luo, Ji-Feng; Li, Yan; Long, Chun-Lin; Kong, Yi

2016-09-01

Six amides, piperbonamides A-F, three neolignans piperbonins A-C, and 11 known compounds were isolated from the aerial parts of Piper bonii (Piperaceae). The structures of piperbonamides A-F and piperbonins A-C were elucidated based on the analysis of 1D and 2D NMR and MS data. Piperbonin A, (+)-trans-acuminatin, (+)-cis-acuminatin, (+)-kadsurenone, and pipernonaline showed weak activity against platelet aggregation with IC50 values of 118.2, 108.5, 90.02, 107.3, and 116.3 μM, respectively, as compared with the positive control, tirofiban, with an IC50 value of 5.24 μM. Piperbonamides A-F were inactive against five tumor cell lines at concentrations up to 40 μM. Copyright © 2016. Published by Elsevier Ltd.

Synthesis and evaluation of novel triazoles and mannich bases functionalized 1,4-dihydropyridine as angiotensin converting enzyme (ACE) inhibitors.

PubMed

Kumbhare, Ravindra M; Kosurkar, Umesh B; Bagul, Pankaj K; Kanwal, Abhinav; Appalanaidu, K; Dadmal, Tulshiram L; Banerjee, Sanjay Kumar

2014-11-01

A series of novel diethyl 2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate embedded triazole and mannich bases were synthesized, and evaluated for their angiotensin converting enzyme (ACE) inhibitory activity. Screening of above synthesized compounds for ACE inhibition showed that triazoles functionalized compounds have better ACE inhibitory activity compared to that of mannich bases analogues. Among all triazoles we found 6 h, 6 i and 6 j to have good ACE inhibition activity with IC50 values 0.713 μM, 0.409 μM and 0.653 μM, respectively. Among mannich bases series compounds, only 7c resulted as most active ACE inhibitor with IC50 value of 0.928 μM. Copyright © 2014. Published by Elsevier Ltd.

In vitro anti-proliferative and anti-inflammatory activity of leaf and fruit extracts from Vaccinium bracteatum Thunb.

PubMed

Landa, Premysl; Skalova, Lenka; Bousova, Iva; Kutil, Zsofia; Langhansova, Lenka; Lou, Ji-Dong; Vanek, Tomas

2014-01-01

The aim of this study was to evaluate in vitro anti-proliferative (tested on MCF-7, MDA-MB-231, and MCF-10A cell lines) and anti-inflammatory (evaluated as inhibition of prostaglandin E2 synthesis catalyzed by cyclooxygenase-2) effect of various extracts from Vaccinium bracteatum leaves and fruits. The highest anti-proliferative effect possessed leaf dichloromethane extract with IC50 values ranging from 93 to 198 μg/mL. In the case of cyclooxygenase-2 inhibition, n-hexane, dichloromethane, and ethanol fruit extracts showed the best activity with IC50 values = 2.0, 5.4, and 12.7 μg/mL, respectively. These results indicate that V. bracteatum leaves and fruits could be useful source of anti-cancer and anti-inflammatory compounds.

Physiological epidermal growth factor concentrations activate high affinity receptors to elicit calcium oscillations.

PubMed

Marquèze-Pouey, Béatrice; Mailfert, Sébastien; Rouger, Vincent; Goaillard, Jean-Marc; Marguet, Didier

2014-01-01

Signaling mediated by the epidermal growth factor (EGF) is crucial in tissue development, homeostasis and tumorigenesis. EGF is mitogenic at picomolar concentrations and is known to bind its receptor on high affinity binding sites depending of the oligomerization state of the receptor (monomer or dimer). In spite of these observations, the cellular response induced by EGF has been mainly characterized for nanomolar concentrations of the growth factor, and a clear definition of the cellular response to circulating (picomolar) concentrations is still lacking. We investigated Ca2+ signaling, an early event in EGF responses, in response to picomolar doses in COS-7 cells where the monomer/dimer equilibrium is unaltered by the synthesis of exogenous EGFR. Using the fluo5F Ca2+ indicator, we found that picomolar concentrations of EGF induced in 50% of the cells a robust oscillatory Ca2+ signal quantitatively similar to the Ca2+ signal induced by nanomolar concentrations. However, responses to nanomolar and picomolar concentrations differed in their underlying mechanisms as the picomolar EGF response involved essentially plasma membrane Ca2+ channels that are not activated by internal Ca2+ store depletion, while the nanomolar EGF response involved internal Ca2+ release. Moreover, while the picomolar EGF response was modulated by charybdotoxin-sensitive K+ channels, the nanomolar response was insensitive to the blockade of these ion channels.

Identification of a novel malonyl-CoA IC(50) for CPT-I: implications for predicting in vivo fatty acid oxidation rates.

PubMed

Smith, Brennan K; Perry, Christopher G R; Koves, Timothy R; Wright, David C; Smith, Jeffrey C; Neufer, P Darrell; Muoio, Deborah M; Holloway, Graham P

2012-11-15

Published values regarding the sensitivity (IC(50)) of CPT-I (carnitine palmitoyltransferase I) to M-CoA (malonyl-CoA) inhibition in isolated mitochondria are inconsistent with predicted in vivo rates of fatty acid oxidation. Therefore we have re-examined M-CoA inhibition kinetics under various P-CoA (palmitoyl-CoA) concentrations in both isolated mitochondria and PMFs (permeabilized muscle fibres). PMFs have an 18-fold higher IC(50) (0.61 compared with 0.034 μM) in the presence of 25 μM P-CoA and a 13-fold higher IC(50) (6.3 compared with 0.49 μM) in the presence of 150 μM P-CoA compared with isolated mitochondria. M-CoA inhibition kinetics determined in PMFs predicts that CPT-I activity is inhibited by 33% in resting muscle compared with >95% in isolated mitochondria. Additionally, the ability of M-CoA to inhibit CPT-I appears to be dependent on P-CoA concentration, as the relative inhibitory capacity of M-CoA is decreased with increasing P-CoA concentrations. Altogether, the use of PMFs appears to provide an M-CoA IC(50) that better reflects the predicted in vivo rates of fatty acid oxidation. These findings also demonstrate that the ratio of [P-CoA]/[M-CoA] is critical for regulating CPT-I activity and may partially rectify the in vivo disconnect between M-CoA content and CPT-I flux within the context of exercise and Type 2 diabetes.

Antibacterial metabolites from Australian macrofungi from the genus Cortinarius.

PubMed

Beattie, Karren D; Rouf, Razina; Gander, Louisa; May, Tom W; Ratkowsky, David; Donner, Christopher D; Gill, Melvyn; Grice, I Darren; Tiralongo, Evelin

2010-06-01

In this study, ethyl acetate and aqueous fractions from 117 collections of Australian macrofungi belonging to the mushroom genus Cortinarius were screened for antimicrobial activity against Staphylococcus aureus and Pseudomonas aeruginosa. Overall, the lipophilic fractions were more active than the aqueous fractions. The ethyl acetate fractions of most or all collections of 13 species, namely Cortinarius ardesiacus, C. archeri, C. austrosaginus, C. austrovenetus, C. austroviolaceus, C. coelopus, C. [Dermocybe canaria](2), C. clelandii, C. [D. kula], C. memoria-annae, C. persplendidus, C. sinapicolor, C. vinosipes and forty seven collections of un-described Cortinarius species exhibited IC(50) values of 0.09 mg/mL against S. aureus. In contrast, most or all collections of only four species, namely C. abnormis, C. austroalbidus, C. [D. kula], C. persplendidus, and eleven un-described Cortinarius collections exhibited similar effects against P. aeruginosa (IC(50)

Design and synthesis of chalcone derivatives as potential non-purine xanthine oxidase inhibitors.

PubMed

Bui, Trung Huu; Nguyen, Nhan Trung; Dang, Phu Hoang; Nguyen, Hai Xuan; Nguyen, Mai Thanh Thi

2016-01-01

Based on some previous research, the chalcone derivatives exhibited potent xanthine oxidase inhibitory activity, e.g. sappanchalcone ( 7 ), with IC 50 value of 3.9 μM, was isolated from Caesalpinia sappan . Therefore, objectives of this research are design and synthesis of 7 and other chalcone derivatives by Claisen-Schmidt condensation and then evaluate their XO inhibitory activity. Fifteen chalcone derivatives were synthesized by Claisen-Schmidt condensation, and were evaluated for XO inhibitory activity. Nine out of 15 synthetic chalcones showed inhibitory activity ( 3 ; 5 - 8 ; 10 - 13 ). Sappanchalcone derivatives ( 11 ) (IC 50 , 2.5 μM) and a novel chalcone ( 13 ) (IC 50 , 2.4 μM) displayed strong xanthine oxidase inhibitory activity that is comparable to allopurinol (IC 50 , 2.5 μM). The structure-activity relationship of these chalcone derivatives was also presented. It is the first research on synthesis sappanchalcone ( 7 ) by Claisen-Schmidt condensation. The overall yield of this procedure was 6.6 %, higher than that of reported procedure (4 %). Design, synthesis, and evaluation of chalcone derivatives were carried out. This result suggests that the chalcone derivative can be used as potential non-purine XO inhibitors.Graphical abstractThe chalcone derivatives as potential non-purine xanthine oxidase inhibitors.

Screening of Latin American plants for antiparasitic activities against malaria, Chagas disease, and leishmaniasis.

PubMed

Calderón, Angela I; Romero, Luz I; Ortega-Barría, Eduardo; Solís, Pablo N; Zacchino, Susana; Gimenez, Alberto; Pinzón, Roberto; Cáceres, Armando; Tamayo, Giselle; Guerra, Carlos; Espinosa, Alex; Correa, Mireya; Gupta, Mahabir P

2010-05-01

In order to explore rationally the medical potential of the plant biodiversity of the Central and South American region as a source of novel antiparasitic molecules, a multinational Organization of American States (OAS) project, which included the participation of multidisciplinary research centers from Argentina, Bolivia, Colombia, Costa Rica, Guatemala, Nicaragua and Panama, was carried out during the period 2001-2004. This project aimed at screening organic plant extracts for antitrypanosomal, antileishmanial and antimalarial activities and subsequently isolating and characterizing bioactive molecules. Plants for antiparasitic screening were selected from a database of ethnomedical uses of Latin American plants (PlanMedia) based on the amount of biological and chemical information available in the literature. We report here the evaluation of 452 extracts from 311 plant species in vitro screens against Plasmodium falciparum, Leishmania mexicana, and Trypanosoma cruzi. Out of 311 species tested, 17 plants (5.4%) showed antiparasitic activities at IC(50) values < or = 10 microg/mL. The most active plants were Acnistus arborescens (L.) Schltdl. (Solanaceae) (leaf, EtOH, IC(50): 4 microg/mL) Monochaetum myrtoideum Naudin (Melastomataceae) (leaf, MeOH, IC(50): 5 microg/mL) and Bourreria huanita (Lex.) Hemsl. (Boraginaceae) (branch, EtOH, IC(50): 6 microg/mL). These were selectively active against P. falciparum, L. mexicana and T. cruzi, respectively.

Antioxidant activities of Physalis peruviana.

PubMed

Wu, Sue-Jing; Ng, Lean-Teik; Huang, Yuan-Man; Lin, Doung-Liang; Wang, Shyh-Shyan; Huang, Shan-Ney; Lin, Chun-Ching

2005-06-01

Physalis peruviana (PP) is a widely used medicinal herb for treating cancer, malaria, asthma, hepatitis, dermatitis and rheumatism. In this study, the hot water extract (HWEPP) and extracts prepared from different concentrations of ethanol (20, 40, 60, 80 and 95% EtOH) from the whole plant were evaluated for antioxidant activities. Results displayed that at 100 mug/ml, the extract prepared from 95% EtOH exhibited the most potent inhibition rate (82.3%) on FeCl2-ascorbic acid induced lipid peroxidation in rat liver homogenate. At concentrations 10-100 microg/ml, this extract also demonstrated the strongest superoxide anion scavenging and inhibitory effect on xanthine oxidase activities. In general, the ethanol extracts revealed a stronger antioxidant activity than alpha-tocopherol and HWEPP. Compared to alpha-tocopherol, the IC50 value of 95% EtOH PP extract was lower in thiobarbituric acid test (IC50=23.74 microg/ml vs. 26.71 microg/ml), in cytochrome c test (IC50=10.40 microg/ml vs. 13.39 microg/ml) and in xanthine oxidase inhibition test (IC50=8.97 microg/ml vs. 20.68 microg/ml). The present study concludes that ethanol extracts of PP possess good antioxidant activities, and the highest antioxidant properties were obtained from the 95% EtOH PP.

Hypoxia affects cellular responses to plant extracts.

PubMed

Liew, Sien-Yei; Stanbridge, Eric J; Yusoff, Khatijah; Shafee, Norazizah

2012-11-21

Microenvironmental conditions contribute towards varying cellular responses to plant extract treatments. Hypoxic cancer cells are known to be resistant to radio- and chemo-therapy. New therapeutic strategies specifically targeting these cells are needed. Plant extracts used in Traditional Chinese Medicine (TCM) can offer promising candidates. Despite their widespread usage, information on their effects in hypoxic conditions is still lacking. In this study, we examined the cytotoxicity of a series of known TCM plant extracts under normoxic versus hypoxic conditions. Pereskia grandifolia, Orthosiphon aristatus, Melastoma malabathricum, Carica papaya, Strobilanthes crispus, Gynura procumbens, Hydrocotyle sibthorpioides, Pereskia bleo and Clinacanthus nutans leaves were dried, blended into powder form, extracted in methanol and evaporated to produce crude extracts. Human Saos-2 osteosarcoma cells were treated with various concentrations of the plant extracts under normoxia or hypoxia (0.5% oxygen). 24h after treatment, an MTT assay was performed and the IC(50) values were calculated. Effect of the extracts on hypoxia inducible factor (HIF) activity was evaluated using a hypoxia-driven firefly luciferase reporter assay. The relative cytotoxicity of each plant extract on Saos-2 cells was different in hypoxic versus normoxic conditions. Hypoxia increased the IC(50) values for Pereskia grandifola and Orthosiphon aristatus extracts, but decreased the IC(50) values for Melastoma malabathricum and Carica papaya extracts. Extracts of Strobilanthes crispus, Gynura procumbens, Hydrocotyle sibthorpioides had equivalent cytotoxic effects under both conditions. Pereskia bleo and Clinacanthus nutans extracts were not toxic to cells within the concentration ranges tested. The most interesting result was noted for the Carica papaya extract, where its IC(50) in hypoxia was reduced by 3-fold when compared to the normoxic condition. This reduction was found to be associated with HIF inhibition. Hypoxia variably alters the cytotoxic effects of TCM plant extracts on cancer cells. Carica papaya showed enhanced cytotoxic effect on hypoxic cancer cells by inhibiting HIF activities. These findings provide a plausible approach to killing hypoxic cancer cells in solid tumors. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Anticancer, antioxidant, and antibacterial activities of low molecular weight bioactive subfractions isolated from cultures of wood degrading fungus Cerrena unicolor

PubMed Central

Jaszek, Magdalena; Stefaniuk, Dawid; Ciszewski, Tomasz; Matuszewski, Łukasz

2018-01-01

The aim of this study is to investigate in vitro the anticancer, antioxidant, and antibacterial activities of three low molecular weight subfractions I, II and III isolated from secondary metabolites produced by the wood degrading fungus Cerrena unicolor. The present study demonstrated that the low molecular weight subfractions III exhibited the strongest inhibitory activity towards breast carcinoma cells MDA-MB-231, prostatic carcinoma cells PC3, and breast cancer cells MCF7 with the half-maximal inhibitory concentration (IC50) value of 52,25 μg/mL, 60,66 μg/mL, and 54,92 μg/mL, respectively. The highest percentage of inhibition was noted at a concentration of 300 μg/mL in all the examined tumor lines. A significant percentage (59.08%) of ex-LMSIII inhibition of the MDA-MB-231 tumor line was reached at a concentration of 15 μg/ml, while the concentration applied did not affect normal human fibroblast cells. The low molecular weight subfraction III was the most effective and additionally showed the highest free radical 1,1-diphenyl-2-picryl-hydrazyl scavenging activity (IC50 20.39 μg/mL) followed by the low molecular weight subfraction I (IC50 64.14 μg/mL) and II (IC50 49.22 μg/mL). The antibacterial activity of the tested preparations was evaluated against three microorganisms: Bacillus subtilis, Staphylococcus aureus, and Escherichia coli. The MIC minimal inhibitory concentration (MIC) values for the low molecular weight subfraction I, II, and III showed a stronger inhibition effect on S. aureus than on B. subtilis and E. coli cells. The MIC values for the low molecular weight subfraction II against S. aureus, B. subtilis, and E. coli were 6.25, 12.5, and 100 mg/mL, respectively. PMID:29874240

Block of high-threshold calcium channels by the synthetic polyamines sFTX-3.3 and FTX-3.3.

PubMed

Norris, T M; Moya, E; Blagbrough, I S; Adams, M E

1996-10-01

A polyamine component of Agelenopsis aperta spider venom designated FTX is reported to be a selective antagonist of P-type calcium channels in the mammalian brain. Consequently, this component has frequently been used as a pharmacological tool to determine the presence, distribution, and function of P-type channels in physiological systems. We describe antagonism of calcium channels by the synthesized polyamine FTX-3.3, which has the proposed structure of natural FTX. We also examined a corresponding polyamine amide, sFTX-3.3. These polyamines are critically evaluated for antagonism of three high-threshold calcium channel subtypes in rat neurons through the use of the whole-cell patch-clamp technique. FTX-3.3 (IC50 = approximately 0.13 mM) is approximately twice as potent as sFTX-3.3 (IC50 = approximately 0.24 mM) against P-type channels and approximately 3-fold more potent against N-type channels (FTX-3.3, IC50 = approximately 0.24 mM; sFTX-3.3, IC50 = approximately 0.70 mM). Both polyamines also block L-type calcium channels with similar potencies. sFTX-3.3 (1 mM) and FTX-3.3 (0.5 mM) typically block 50% and 65% of Bay K8644-enhanced L-type current, respectively. Antagonism of each calcium channel subtype is voltage dependent, with less inhibition of Ba2+ currents at more-positive potentials. These data show that both sFTX-3.3 and FTX-3.3 antagonize P-, N-, and L-type calcium channels in mammalian Purkinje and superior cervical ganglia neurons with similar IC50 values.

Prioritizing pharmacokinetic drug interaction precipitants in natural products: application to OATP inhibitors in grapefruit juice.

PubMed

Johnson, Emily J; Won, Christina S; Köck, Kathleen; Paine, Mary F

2017-04-01

Natural products, including botanical dietary supplements and exotic drinks, represent an ever-increasing share of the health-care market. The parallel ever-increasing popularity of self-medicating with natural products increases the likelihood of co-consumption with conventional drugs, raising concerns for unwanted natural product-drug interactions. Assessing the drug interaction liability of natural products is challenging due to the complex and variable chemical composition inherent to these products, necessitating a streamlined preclinical testing approach to prioritize precipitant individual constituents for further investigation. Such an approach was evaluated in the current work to prioritize constituents in the model natural product, grapefruit juice, as inhibitors of intestinal organic anion-transporting peptide (OATP)-mediated uptake. Using OATP2B1-expressing MDCKII cells (Madin-Darby canine kidney type II) and the probe substrate estrone 3-sulfate, IC 50s were determined for constituents representative of the flavanone (naringin, naringenin, hesperidin), furanocoumarin (bergamottin, 6',7'-dihydroxybergamottin) and polymethoxyflavone (nobiletin and tangeretin) classes contained in grapefruit juice. Nobiletin was the most potent (IC 50 , 3.7 μm); 6',7'-dihydroxybergamottin, naringin, naringenin and tangeretin were moderately potent (IC 50 , 20-50 μm); and bergamottin and hesperidin were the least potent (IC 50 , >300 μm) OATP2B1 inhibitors. Intestinal absorption simulations based on physiochemical properties were used to determine the ratios of unbound concentration to IC 50 for each constituent within enterocytes and to prioritize in order of pre-defined cut-off values. This streamlined approach could be applied to other natural products that contain multiple precipitants of natural product-drug interactions. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Impact of FDA-Approved Drugs on the Prostaglandin Transporter OATP2A1/SLCO2A1.

PubMed

Kamo, Shunsuke; Nakanishi, Takeo; Aotani, Rika; Nakamura, Yoshinobu; Gose, Tomoka; Tamai, Ikumi

2017-09-01

To understand interaction of drugs with the prostaglandin transporter OATP2A1/SLCO2A1 that regulates disposition of prostaglandins, we explored the impact of 636 drugs in an FDA-approved drug library on 6-carboxyfluorescein (6-CF) uptake by OATP2A1-expressing HEK293 cells (HEK/2A1). Fifty-one and 10 drugs were found to inhibit and enhance 6-CF uptake by more than 50%, respectively. Effect of the 51 drugs on 6-CF uptake was positively correlated with that on PGE 2 uptake (r = 0.64, p < 0.001). Among those, 5 drugs not structurally related to prostaglandins, suramin, pranlukast, zafirlukast, olmesartan medoxomil, and losartan potassium, exhibited more than 90% PGE 2 uptake inhibition. Inhibitory affinity of suramin to OATP2A1 was the highest (IC 50,2A1 of 0.17 μM), and its IC 50 values to MRP4-mediated PGE 2 transport (IC 50,MRP4 ) and PGE 2 synthesis in human U-937 cells treated with phorbol 12-myristate 13-acetate (IC 50,Syn ) were 73.6 and 336.7 times higher than IC 50,2A1 , respectively. Moreover, structure-activity relationship study in 29 nonsteroidal anti-inflammatory drugs contained in the library displayed inhibitory activities of anthranilic acid derivatives, but enhancing effects of propionic acid derivatives. These results demonstrate that suramin is a potent selective inhibitor of OATP2A1, providing a comprehensive information about drugs in clinical use that interact with OATP2A1. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

[A study for testing the antifungal susceptibility of yeast by the Japanese Society for Medical Mycology (JSMM) method. The proposal of the modified JSMM method 2009].

PubMed

Nishiyama, Yayoi; Abe, Michiko; Ikeda, Reiko; Uno, Jun; Oguri, Toyoko; Shibuya, Kazutoshi; Maesaki, Shigefumi; Mohri, Shinobu; Yamada, Tsuyoshi; Ishibashi, Hiroko; Hasumi, Yayoi; Abe, Shigeru

2010-01-01

The Japanese Society for Medical Mycology (JSMM) method used for testing the antifungal susceptibility of yeast, the MIC end point for azole antifungal agents, is currently set at IC(80). It was recently shown, however that there is an inconsistency in the MIC value between the JSMM method and the CLSI M27-A2 (CLSI) method, in which the end- point was to read as IC(50). To resolve this discrepancy and reassess the JSMM method, the MIC for three azoles, fluconazole, itraconazole and voriconazole were compared to 5 strains of each of the following Candida species: C. albicans, C. glabrata, C. tropicalis, C. parapsilosis and C. krusei, for a total of 25 comparisons, using the JSMM method, a modified JSMM method, and the CLSI method. The results showed that when the MIC end- point criterion of the JSMM method was changed from IC(80) to IC(50) (the modified JSMM method) , the MIC value was consistent and compatible with the CLSI method. Finally, it should be emphasized that the JSMM method, using a spectrophotometer for MIC measurement, was superior in both stability and reproducibility, as compared to the CLSI method in which growth was assessed by visual observation.

Carbachol-induced phosphoinositide turnover in NCB-20 cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chuang, D.M.; Dillon-Carter, O.

NCB-20 cells (fetal Chinese hamster brain cell x neuroblastoma hybrids) have been shown to contain a variety of neurotransmitter receptors. The authors now report that this cloned cell line also contains acetylcholne receptors which are linked to phospholipase C. Confluent cell cultures were preincubated with /sup 3/H-myo-inositol to label endogenous phosphoinositide (PI) and the accumulation of a PI metabolite, inositol monophosphate (IP/sub 1/), was measured in the presence of LiCl. Carbachol increased IP/sub 1/), accumulation be more than 400% with a EC/sub 50/ of about 50 ..mu..M. Acetylcholine and muscarine were also effective, whereas oxotremorine and McN-A-343 were weak inmore » both potency and efficacy. The carbachol-induced IP/sub 1/ accumulation was completely blocked by atropine (Ki approx. 0.6 nM) and pirenzepine (Ki approx. 15 nM). The presence of KCl was not required for the carbachol-induced effect. The formation of inositol bis- and triphosphate was also increased carbachol; these increases occurred earlier but were of much smaller magnitude. Pretreatment of cells with 4 ..beta..-phorbol dibutyrate or 4 ..beta..-phorbol myristate acetate was found to attenuate the carbachol-induced formation of IP/sub 1/ (IC/sub 50/ in the low nanomolar concentration ranges), however 4 ..beta..-phorbol, the biologically inactive phorbol ester, was ineffective in causing this attenuation. These results suggest a feedback inhibition of PI turnover in NCB-20 cells through the action of protein kinase C.« less

Anti-inflammatory and cytotoxic activities of Bursera copallifera

PubMed Central

Columba-Palomares, M. F. María C.; Villareal, Dra. María L.; Acevedo Quiroz, M. C. Macdiel E.; Marquina Bahena, M. C. Silvia; Álvarez Berber, Dra. Laura P.; Rodríguez-López, Dra. Verónica

2015-01-01

Background: The plant species Bursera copallifera (DC) bullock is used in traditional medicine to treat inflammation. The leaves of this plant can be prepared as an infusion to treat migraines, bronchitis, and dental pain Objective: The purpose of this study was to determine the anti-inflammatory and cytotoxic activities of organic extracts from the stems, stem bark, and leaves of B. copallifera, which was selected based on the knowledge of its traditional use. Materials and Methods: We evaluated the ability of extracts to inhibit mouse ear inflammation in response to topical application of 12-O tetradecanoylphorbol-13-acetate. The extracts with anti-inflammatory activity were evaluated for their inhibition of pro-inflammatory enzymes. In addition, the in vitro cytotoxic activities of the organic extracts were evaluated using the sulforhodamine B assay. Results: The hydroalcoholic extract of the stems (HAS) exhibited an anti-inflammatory activity of 54.3% (0.5 mg/ear), whereas the anti-inflammatory activity of the dichloromethane-methanol extract from the leaves (DMeL) was 55.4% at a dose of 0.1 mg/ear. Methanol extract from the leaves (MeL) showed the highest anti-inflammatory activity (IC50 = 4.4 μg/mL), hydroalcoholic extract of leaves, and DMeL also reduce the enzyme activity, (IC50 = 6.5 μg/mL, IC50 = 5.7 μg/mL), respectively, from stems HAS exhibit activity at the evaluated concentrations (IC50 =6.4 μg/mL). The hydroalcoholic extract of the stems exhibited the highest cytotoxic activity against a breast adenocarcinoma cell line (MCF7, IC50 = 0.90 μg/mL), whereas DMeL exhibited an IC50 value of 19.9 μg/mL. Conclusion: In conclusion, extracts from leaves and stems inhibited cyclooxygenase-1, which is the target enzyme for nonsteroidal anti inflammatory drugs, and some of these extracts demonstrated substantial antiproliferative effects against the MCF7 cell line. These results validate the traditional use of B. copallifera. PMID:26664022

Anti-inflammatory and cytotoxic activities of Bursera copallifera.

PubMed

Columba-Palomares, M F María C; Villareal, Dra María L; Acevedo Quiroz, M C Macdiel E; Marquina Bahena, M C Silvia; Álvarez Berber, Dra Laura P; Rodríguez-López, Dra Verónica

2015-10-01

The plant species Bursera copallifera (DC) bullock is used in traditional medicine to treat inflammation. The leaves of this plant can be prepared as an infusion to treat migraines, bronchitis, and dental pain. The purpose of this study was to determine the anti-inflammatory and cytotoxic activities of organic extracts from the stems, stem bark, and leaves of B. copallifera, which was selected based on the knowledge of its traditional use. We evaluated the ability of extracts to inhibit mouse ear inflammation in response to topical application of 12-O tetradecanoylphorbol-13-acetate. The extracts with anti-inflammatory activity were evaluated for their inhibition of pro-inflammatory enzymes. In addition, the in vitro cytotoxic activities of the organic extracts were evaluated using the sulforhodamine B assay. The hydroalcoholic extract of the stems (HAS) exhibited an anti-inflammatory activity of 54.3% (0.5 mg/ear), whereas the anti-inflammatory activity of the dichloromethane-methanol extract from the leaves (DMeL) was 55.4% at a dose of 0.1 mg/ear. Methanol extract from the leaves (MeL) showed the highest anti-inflammatory activity (IC50 = 4.4 μg/mL), hydroalcoholic extract of leaves, and DMeL also reduce the enzyme activity, (IC50 = 6.5 μg/mL, IC50 = 5.7 μg/mL), respectively, from stems HAS exhibit activity at the evaluated concentrations (IC50 =6.4 μg/mL). The hydroalcoholic extract of the stems exhibited the highest cytotoxic activity against a breast adenocarcinoma cell line (MCF7, IC50 = 0.90 μg/mL), whereas DMeL exhibited an IC50 value of 19.9 μg/mL. In conclusion, extracts from leaves and stems inhibited cyclooxygenase-1, which is the target enzyme for nonsteroidal anti inflammatory drugs, and some of these extracts demonstrated substantial antiproliferative effects against the MCF7 cell line. These results validate the traditional use of B. copallifera.

Linalool, a Piper aduncum essential oil component, has selective activity against Trypanosoma cruzi trypomastigote forms at 4°C

PubMed Central

Villamizar, Luz Helena; Cardoso, Maria das Graças; de Andrade, Juliana; Teixeira, Maria Luisa; Soares, Maurilio José

2017-01-01

BACKGROUND Recent studies showed that essential oils from different pepper species (Piper spp.) have promising leishmanicidal and trypanocidal activities. OBJECTIVES In search for natural compounds against Trypanosoma cruzi, different forms of the parasite were incubated for 24 h at 28ºC or 4ºC with Piper aduncum essential oil (PaEO) or its main constituents linalool and nerolidol. METHODS PaEO chemical composition was obtained by GC-MS. Drug activity assays were based on cell counting, MTT data or infection index values. The effect of PaEO on the T. cruzi cell cycle and mitochondrial membrane potential was evaluated by flow cytometry. FINDINGS PaEO was effective against cell-derived (IC50/24 h: 2.8 μg/mL) and metacyclic (IC50/24 h: 12.1 μg/mL) trypomastigotes, as well as intracellular amastigotes (IC50/24 h: 9 μg/mL). At 4ºC - the temperature of red blood cells (RBCs) storage in blood banks - cell-derived trypomastigotes were more sensitive to PaEO (IC50/24 h = 3.8 μg/mL) than to gentian violet (IC50/24 h = 24.7 mg/mL). Cytotoxicity assays using Vero cells (37ºC) and RBCs (4ºC) showed that PaEO has increased selectivity for cell-derived trypomastigotes. Flow cytometry analysis showed that PaEO does not affect the cell cycle of T. cruzi epimastigotes, but decreases their mitochondrial membrane potential. GC-MS data identified nerolidol and linalool as major components of PaEO, and linalool had trypanocidal effect (IC50/24 h: 306 ng/mL) at 4ºC. MAIN CONCLUSION The trypanocidal effect of PaEO is likely due to the presence of linalool, which may represent an interesting candidate for use in the treatment of potentially contaminated RBCs bags at low temperature. PMID:28177047

Linalool, a Piper aduncum essential oil component, has selective activity against Trypanosoma cruzi trypomastigote forms at 4°C.

PubMed

Villamizar, Luz Helena; Cardoso, Maria das Graças; Andrade, Juliana de; Teixeira, Maria Luisa; Soares, Maurilio José

2017-02-01

Recent studies showed that essential oils from different pepper species (Piper spp.) have promising leishmanicidal and trypanocidal activities. In search for natural compounds against Trypanosoma cruzi, different forms of the parasite were incubated for 24 h at 28ºC or 4ºC with Piper aduncum essential oil (PaEO) or its main constituents linalool and nerolidol. PaEO chemical composition was obtained by GC-MS. Drug activity assays were based on cell counting, MTT data or infection index values. The effect of PaEO on the T. cruzi cell cycle and mitochondrial membrane potential was evaluated by flow cytometry. PaEO was effective against cell-derived (IC50/24 h: 2.8 μg/mL) and metacyclic (IC50/24 h: 12.1 μg/mL) trypomastigotes, as well as intracellular amastigotes (IC50/24 h: 9 μg/mL). At 4ºC - the temperature of red blood cells (RBCs) storage in blood banks - cell-derived trypomastigotes were more sensitive to PaEO (IC50/24 h = 3.8 μg/mL) than to gentian violet (IC50/24 h = 24.7 mg/mL). Cytotoxicity assays using Vero cells (37ºC) and RBCs (4ºC) showed that PaEO has increased selectivity for cell-derived trypomastigotes. Flow cytometry analysis showed that PaEO does not affect the cell cycle of T. cruzi epimastigotes, but decreases their mitochondrial membrane potential. GC-MS data identified nerolidol and linalool as major components of PaEO, and linalool had trypanocidal effect (IC50/24 h: 306 ng/mL) at 4ºC. The trypanocidal effect of PaEO is likely due to the presence of linalool, which may represent an interesting candidate for use in the treatment of potentially contaminated RBCs bags at low temperature.

Investigating the inhibitory effect of cyanide, phenol and 4-nitrophenol on the activated sludge process employed for the treatment of petroleum wastewater.

PubMed

Inglezakis, V J; Malamis, S; Omirkhan, A; Nauruzbayeva, J; Makhtayeva, Z; Seidakhmetov, T; Kudarova, A

2017-12-01

In this work, the inhibitory effect of cyanide, phenol and 4-nitrophenol on the activated sludge process was investigated. The inhibition of the aerobic oxidation of organic matter, nitrification and denitrification were examined in batch reactors by measuring the specific oxygen uptake rate (sOUR), the specific ammonium uptake rate (sAUR) and the specific nitrogen uptake rate (sNUR) respectively. The tested cyanide, phenol and 4-nitrophenol concentrations were 0.2-1.7 mg/L, 4.8-73.1 mg/L and 8.2-73.0 mg/L respectively. Cyanide was highly toxic as it significantly (>50%) inhibited the activity of autotrophic biomass, heterotrophic biomass under aerobic conditions and denitrifiers even at relatively low concentrations (1.0-1.7 mgCN - /L). The determination of the half maximum inhibitory concentration (IC 50 ) confirmed this, since for cyanide IC 50 values were very low for the examined bioprocesses (<1.5 mg/L). On the other hand, the IC 50 values for phenol and 4-nitrophenol were much higher (>25 mg/L) for the tested bioprocesses since appreciable concentrations were required to accomplish significant inhibition. The autotrophic bacteria were more sensitive to phenol than the aerobic heterotrophs. The denitrifiers were found to be very resistant to phenol. Copyright © 2016. Published by Elsevier Ltd.

Synthesis and β-glucuronidase inhibitory potential of benzimidazole derivatives.

PubMed

Khan, Khalid Mohammed; Khan, Momin; Ambreen, Nida; Rahim, Fazal; Naureen, Shagufta; Perveen, Shahnaz; Choudhary, M Iqbal; Voelter, Wolfgang

2012-05-01

Benzimidazole derivatives 1-24 have been synthesized and their in vitro β-glucuronidase inhibitory activitiy was evaluated. Compounds 15 (IC50=6.33+/-0.40 μM), 7 (IC50=22.0+/-0.33 μM), 2 (IC50=23.1+/-1.78 μM), 17 (IC50=23.9+/-1.46 μM), and 3 (IC50=33.8+/-1.61 μM) showed more potent β-glucuronidase inhibitory activity than the standard (D-saccharic acid 1,4 lactone, IC50=48.4+/-1.25 μM). This study has identified a new series of potential β-glucuronidase inhibitors. A structure-activity relationship has also been studied.

Overexpression of Wild-Type Aspartokinase Increases l-Lysine Production in the Thermotolerant Methylotrophic Bacterium Bacillus methanolicus▿

PubMed Central

Jakobsen, Øyvind M.; Brautaset, Trygve; Degnes, Kristin F.; Heggeset, Tonje M. B.; Balzer, Simone; Flickinger, Michael C.; Valla, Svein; Ellingsen, Trond E.

2009-01-01

Aspartokinase (AK) controls the carbon flow into the aspartate pathway for the biosynthesis of the amino acids l-methionine, l-threonine, l-isoleucine, and l-lysine. We report here the cloning of four genes (asd, encoding aspartate semialdehyde dehydrogenase; dapA, encoding dihydrodipicolinate synthase; dapG, encoding AKI; and yclM, encoding AKIII) of the aspartate pathway in Bacillus methanolicus MGA3. Together with the known AKII gene lysC, dapG and yclM form a set of three AK genes in this organism. Overexpression of dapG, lysC, and yclM increased l-lysine production in wild-type B. methanolicus strain MGA3 2-, 10-, and 60-fold (corresponding to 11 g/liter), respectively, without negatively affecting the specific growth rate. The production levels of l-methionine (less than 0.5 g/liter) and l-threonine (less than 0.1 g/liter) were low in all recombinant strains. The AK proteins were purified, and biochemical analyses demonstrated that they have similar Vmax values (between 47 and 58 μmol/min/mg protein) and Km values for l-aspartate (between 1.9 and 5.0 mM). AKI and AKII were allosterically inhibited by meso-diaminopimelate (50% inhibitory concentration [IC50], 0.1 mM) and by l-lysine (IC50, 0.3 mM), respectively. AKIII was inhibited by l-threonine (IC50, 4 mM) and by l-lysine (IC50, 5 mM), and this enzyme was synergistically inhibited in the presence of both of these amino acids at low concentrations. The correlation between the impact on l-lysine production in vivo and the biochemical properties in vitro of the individual AK proteins is discussed. This is the first example of improving l-lysine production by metabolic engineering of B. methanolicus and also the first documentation of considerably increasing l-lysine production by overexpression of a wild-type AK. PMID:19060158

Overexpression of wild-type aspartokinase increases L-lysine production in the thermotolerant methylotrophic bacterium Bacillus methanolicus.

PubMed

Jakobsen, Oyvind M; Brautaset, Trygve; Degnes, Kristin F; Heggeset, Tonje M B; Balzer, Simone; Flickinger, Michael C; Valla, Svein; Ellingsen, Trond E

2009-02-01

Aspartokinase (AK) controls the carbon flow into the aspartate pathway for the biosynthesis of the amino acids l-methionine, l-threonine, l-isoleucine, and l-lysine. We report here the cloning of four genes (asd, encoding aspartate semialdehyde dehydrogenase; dapA, encoding dihydrodipicolinate synthase; dapG, encoding AKI; and yclM, encoding AKIII) of the aspartate pathway in Bacillus methanolicus MGA3. Together with the known AKII gene lysC, dapG and yclM form a set of three AK genes in this organism. Overexpression of dapG, lysC, and yclM increased l-lysine production in wild-type B. methanolicus strain MGA3 2-, 10-, and 60-fold (corresponding to 11 g/liter), respectively, without negatively affecting the specific growth rate. The production levels of l-methionine (less than 0.5 g/liter) and l-threonine (less than 0.1 g/liter) were low in all recombinant strains. The AK proteins were purified, and biochemical analyses demonstrated that they have similar V(max) values (between 47 and 58 micromol/min/mg protein) and K(m) values for l-aspartate (between 1.9 and 5.0 mM). AKI and AKII were allosterically inhibited by meso-diaminopimelate (50% inhibitory concentration [IC(50)], 0.1 mM) and by l-lysine (IC(50), 0.3 mM), respectively. AKIII was inhibited by l-threonine (IC(50), 4 mM) and by l-lysine (IC(50), 5 mM), and this enzyme was synergistically inhibited in the presence of both of these amino acids at low concentrations. The correlation between the impact on l-lysine production in vivo and the biochemical properties in vitro of the individual AK proteins is discussed. This is the first example of improving l-lysine production by metabolic engineering of B. methanolicus and also the first documentation of considerably increasing l-lysine production by overexpression of a wild-type AK.

Effect of SanOrg123781A, a synthetic hexadecasaccharide, on clot-bound thrombin and factor Xa in vitro and in vivo.

PubMed

Hérault, J-P; Cappelle, M; Bernat, A; Millet, L; Bono, F; Schaeffer, P; Herbert, J-M

2003-09-01

Factor (F)Xa and thrombin bound to the clot during its formation contribute to the propensity of thrombi to activate the coagulation system. The aim of this work was to study the inhibition of clot-bound FXa and clot-bound thrombin by SanOrg123781A, a synthetic hexadecasaccharide that enhances the inhibition of thrombin and FXa by antithrombin (AT). SanOrg123781A, designed to exhibit low non-specific binding to proteins other than AT, was compared with heparin. In buffer, heparin and SanOrg123781A inhibited FXa and thrombin at similar concentrations [concentration inhibiting 50% (IC50) of Xa and IIa activity were, respectively: heparin 120 +/- 7 and 3 +/- 1 ng mL-1; SanOrg123781A 77 +/- 5 and 4 +/- 1 ng mL-1]. In human plasma, the activity of both compounds was reduced, although the activity of heparin was much more affected than that of SanOrg123781A (IC50 values for inhibition of FXa and FIIa activity were, respectively: heparin 100 +/- 5 and 800 +/- 40 ng mL-1; SanOrg123781A 10 +/- 5 and 30 +/- 3 ng mL-1). We demonstrated, in agreement with our previous results, that the procoagulant activity of the clot is essentially due to clot-bound FXa and to some extent to clot-bound thrombin. We showed that heparin and SanOrg123781A were able to inhibit fragment F1+2 generation induced by clot-bound FXa with IC50 values of 2 +/- 0.5 micro g mL-1 and 0.6 +/- 0.2 micro g mL-1, respectively. Both compounds also inhibited clot-bound thrombin activity, the IC50 values of heparin and SanOrg123781A being 1 +/- 0.01 micro g mL-1 and 0.1 +/- 0.1 micro g mL-1, respectively. Moreover, both heparin and SanOrg123781A significantly inhibited fibrinopeptide A generated by the action of clot-bound thrombin on fibrinogen but also by free thrombin generated from prothrombin by clot-bound FXa with IC50 values of 4 +/- 0.6 and 1 +/- 0.1 micro g mL-1, respectively. As with clot-bound enzymatic activities, SanOrg123781A was three times more active than heparin in vivo on fibrinogen accretion onto a pre-existing thrombus and as activators of recombinant tissue-type plasminogen activator-induced thrombolysis. In conclusion, due to the specific activities of SanOrg123781A, this compound is much more active than heparin in the presence of plasma proteins, on clot-bound enzymes and in in vivo models of thrombosis/thrombolysis.

Bioactive phenylpropanoid analogues from Piper betle L. var. birkoli leaves.

PubMed

Atiya, Akhtar; Sinha, Barij Nayan; Lal, Uma Ranjan

2017-11-01

Phytochemical analyses of the chloroform extract of Piper betle L. var. birkoli, Piperaceae, leaves led to the isolation of two new phenylpropanoid analogues: bis-chavicol dodecanoyl ester (2) and bis-hydroxychavicol dodecanoyl ester (3), along with one known compound: allyl-3-methoxy-4-hydroxybenzene (1) on the basis of spectroscopic data 1D ( 1 H and 13 C) and 2D ( 1 H- 1 H COSY and HMBC) NMR, as well as ESI-MS, FT-IR, HR-ESI-MS and LC-ESI-MS. Compound 2 and 3 exhibited excellent antioxidant DPPH radical scavenging activity with IC 50 values of 12.67 μg/mL and 1.08 μg/mL compared to ascorbic acid as a standard antioxidant drug with IC 50 value of 6.60 μg/mL. Evaluation of cytotoxic activity against two human oral cancer cell lines (AW13516 and AW8507) showed significant effect with GI 50 values of 19.61 and 23.01 μg/mL for compound 2 and 10.25 and 13.12 μg/mL for compound 3, compared to Doxorubicin ® as a standard cytotoxic drug with GI 50 value of < 10 μg/mL.

Two novel assays for the detection of haemin-binding properties of antimalarials evaluated with compounds isolated from medicinal plants.

PubMed

Steele, J C P; Phelps, R J; Simmonds, M S J; Warhurst, D C; Meyer, D J

2002-07-01

Forty-two compounds isolated from nine plants used within South America for the treatment of malaria were tested for haemin binding using two novel, rapid screening methods. The data obtained were analysed with respect to IC(50) values for in vitro toxicity to Plasmodium falciparum trophozoites. One method, a multiwell assay based on the inhibition of the interaction of haemin with glutathione (GSH), is sensitive in the 10 microM range, takes c. 1 h and is suitable for either a high throughput screen or rapid assay during natural product isolation. Of 19 compounds showing antiplasmodial activity (IC(50) < 40 microM), 16 (84%) showed >40% inhibition of GSH-haemin reaction. The sensitivity and specificity of the assay were 0.85 and 0.82, respectively. The positive predictive value was 0.81 and the negative predictive value 0.86. A more sensitive assay (0.1 microM range) is based on the reversal by haemin-binding compounds of the haemin inhibition of the L-dopachrome-methyl ester tautomerase activity of human macrophage migration inhibitory factor. This assay gives a better idea of the affinity of interaction and uses very small amounts of test compound. The log[RI(50)] of eight of the compounds that tested positive in the above assays together with those of quinine and chloroquine showed a positive correlation with log[antiplasmodial IC(50)] for strain T9-96 (r = 0.824) and strain K1 (r = 0.904). Several of the antimalarial compounds that bind haemin are isoquinolines, a class not shown previously to interact with haemin.

Studies on the interactions between drugs and estrogen: analytical method for prediction system of gynecomastia induced by drugs on the inhibitory metabolism of estradiol using Escherichia coli coexpressing human CYP3A4 with human NADPH-cytochrome P450 reductase.

PubMed

Satoh, T; Fujita, K I; Munakata, H; Itoh, S; Nakamura, K; Kamataki, T; Itoh, S; Yoshizawa, I

2000-11-15

To establish a prediction system for drug-induced gynecomastia in clinical fields, a model reaction system was developed to explain numerically this side effect. The principle is based on the assumption that 50% inhibition concentration (IC(50)) of drugs on the in vitro metabolism of estradiol (E2) to its major product 2-hydroxyestradiol (2-OH-E2) can be regarded as the index for achieving this purpose. By using human cytochrome P450s coexpressed with human NADPH-cytochrome P450 reductase in Escherichia coli as the enzyme, the reaction was examined. Among the nine enzymes (CYP1A1, 1A2, 2A6, 2C8, 2C9, 2C19, 2D6, 2E1, and 3A4) tested, CYP3A4 having a V(max)/K(m) (ml/min/nmol P450) value of 0.32 for production of 2-OH-E2 was shown to be the most suitable enzyme as the reagent. The inhibitory effects of ketoconazole, cyclosporin A, and cimetidine toward the 2-hydroxylation of E2 catalyzed by CYP3A4 were obtained, and their IC(50) values were 7 nM, 64 nM, and 290 microM, respectively. The present results suggest that IC(50) values thus obtained can be substituted as the prediction index for gynecomastia induced by drugs, considering the patients' individual information. Copyright 2000 Academic Press.

Inhibitory effects of some drugs on carbonic anhydrase enzyme purified from Kangal Akkaraman sheep in Sivas, Turkey.

PubMed

Koçyiğit, Ümit M; Durna Daştan, Sevgi; Taslimi, Parham; Daştan, Taner; Gülçin, İlhami

2018-01-01

In this study, carbonic anhydrase (CA) enzyme was purified and characterized from blood samples of Kangal Akkaraman sheep and inhibitory properties on certain antibiotics were examined. CA purification was composed of preparation of the hemolysate and conducting the Sepharose-4B-tyrosine-sulfanilamide affinity gel chromatography in having specific activity of 11626 EU mg -1 , yield of 14.40%, and 242.76-fold purification. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis was performed to assess the enzyme purity and a single band was observed. Some antibiotics were exhibited in vitro inhibition on the CA activity. IC 50 values of these inhibitors were calculated by plotting activity percentage. IC 50 values of certain drugs (dexamethasone; caffeine; metamizole sodium; tetramisol; ceftiofur HCl; ivermectin; tavilin 50; penokain G; neosym; and sulfamezathine) were found as 0.38, 8.24, 285.53, 114.77, 5.33, 2.76, 27.58, 213.50, 208.28, and 36.60 μM, respectively. K i values of different drugs on Kangal Akkaraman sheep blood CA activity were found in the range of 0.21 ± 0.038-266.64 ± 37.11 μM. © 2017 Wiley Periodicals, Inc.

Protective activity of hamamelitannin on cell damage induced by superoxide anion radicals in murine dermal fibroblasts.

PubMed

Masaki, H; Atsumi, T; Sakurai, H

1995-01-01

Previously we demonstrated that hamamelitannin (2',5-di-O-galloyl hamamelose) in Hamamelis virginiana L. exhibits potent superoxide-anion scavenging activity. We then examined the physiological and pharmacological activities of hamamelitannin as well as its functional homologues, gallic acid and syringic acid. The following results were obtained: (1) Hamamelitannin has a higher protective activity against cell damages induced by superoxide anions than gallic acid which is the functional moiety of hamamelitannin. The protective activity of hamamelitannin on murine fibroblast-damage induced by superoxide anions was found at a minimum concentration of 50 microM, while the corresponding figure for gallic acid was 100 microM. (2) Pre-treatment of fibroblasts with hamamelitannin enhances cell survival. (3) The superoxide-anion scavenging activity of the compound in terms of its IC50 value (50% inhibition concentration of superoxide anion radicals generated) was evaluated by ESR spin-trapping. Both hamamelitannin (IC50 = 1.31 +/- 0.06 microM) and gallic acid (IC50 = 1.01 +/- 0.03 microM) exhibited high superoxide-anion scavenging activity followed by syringic acid (IC50 = 13.90 +/- 2.38 microM). (4) When hamamelitannin was treated with superoxide anions generated by a KO2-crown ether system, HPLC analysis showed the disappearance of hamamelitannin and the concomitant formation of hamamelitannin-derived radicals (g = 2.005, delta H1 = 2.16 G, delta H2 = 4.69 G) was detected by ESR spectrometry.(ABSTRACT TRUNCATED AT 250 WORDS)

Combined in Vitro and in Silico Studies for the Anticholinesterase Activity and Pharmacokinetics of Coumarinyl Thiazoles and Oxadiazoles

PubMed Central

Ibrar, Aliya; Khan, Ajmal; Ali, Majid; Sarwar, Rizwana; Mehsud, Saifullah; Farooq, Umar; Halimi, Syed M. A.; Khan, Imtiaz; Al-Harrasi, Ahmed

2018-01-01

In a continuation of our previous work for the exploration of novel enzyme inhibitors, two new coumarin-thiazole 6(a–o) and coumarin-oxadiazole 11(a–h) hybrids have been designed and synthesized. All the compounds were characterized by 1H- and 13C-NMR spectroscopy and elemental analysis. New hybrid analogs were evaluated against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) in order to know their potential for the prevention of Alzheimer's disease (AD). In coumarinyl thiazole series, compound 6b was found as the most active member against AChE having IC50 value of 0.87 ± 0.09 μM, while the compound 6j revealed the same efficacy against BuChE with an IC50 value of 11.01 ± 3.37 μM. In case of coumarinyl oxadiazole series, 11a was turned out to be the lead candidate against AChE with an IC50 value of 6.07 ± 0.23 μM, whereas compound 11e was found significantly active against BuChE with an IC50 value of 0.15 ± 0.09 μM. To realize the binding interaction of these compounds with AChE and BuChE, the molecular docking studies were performed. Compounds from coumarinyl thiazole series with potent AChE activity (6b, 6h, 6i, and 6k) were found to interact with AChE in the active site with MOE score of −10.19, −9.97, −9.68, and −11.03 Kcal.mol−1, respectively. The major interactions include hydrogen bonding, π-π stacking with aromatic residues, and interaction through water bridging. The docking studies of coumarinyl oxadiazole derivatives 11(a–h) suggested that the compounds with high anti-butyrylcholinesterase activity (11e, 11a, and 11b) provided MOE score of −9.9, −7.4, and −8.2 Kcal.mol−1, respectively, with the active site of BuChE building π-π stacking with Trp82 and water bridged interaction. PMID:29632858

Antiprotozoal, Antibacterial and Antidiarrheal Properties from the Flowers of Chiranthodendron pentadactylon and Isolated Flavonoids.

PubMed

Calzada, Fernando; Juárez, Teresa; García-Hernández, Normand; Valdes, Miguel; Ávila, Oscar; Mulia, Lilian Yepez; Velázquez, Claudia

2017-01-01

Chiranthodendron pentadactylon Larreat. (Sterculiaceae) is a Mexican plant used in traditional medicine for the treatment of heart disease symptoms and infectious diarrhea. To evaluate in vitro antiprotozoal and antibacterial activities and in vivo antidiarrheal activity from the flowers of C. pentadactylon using the extract, fractions, and major isolated flavonoids. Bioassay-guided fractionation of the methanol extract of C. pentadactylon (MECP) led to the isolation of five flavonoids, tiliroside, astragalin, isoquercitrin, (+)-catechin, and (-)-epicatechin. Antimicrobial activities were tested on two protozoa ( Entamoeba histolytica and Giardia lamblia ) and nine bacterial enteropathogens (two Escherichia coli strains, two Shigella sonnei strains, two Shigella flexneri strains, two Salmonella sp. strains, and Vibrio cholerae ) isolated from feces of children with acute diarrhea or dysentery and resistant to chloramphenicol. Also, antidiarrheal activity was tested on cholera toxin-induced diarrhea in male Balb-c mice. Epicatechin was the most potent antiamoebic and antigiardial compound with IC 50 values of 1.9 μg/mL for E. histolytica and 1.6 μg/mL for G. lamblia ; tiliroside showed moderate antiprotozoal activity against both protozoan. In contrast, in the antibacterial activity, tiliroside was the most potent compound on all microorganisms with minimum inhibitory concentration values less than 0.7 mg/mL. In the case of cholera toxin-induced diarrhea, epicatechin was the most potent flavonoid with IC 50 of 14.7 mg/kg. Epicatechin and tiliroside were the flavonoids responsible for antimicrobial andantidiarrheal activities of C. pentadactylon . Its antiprotozoal, antibacterial, and antidiarrheal properties are in good agreement with the traditional medicinal use of C. pentadactylon for the treatment of infectious diarrhea. Epicatechin was the most potent antiamoebic and antigiardial compound with IC 50 values of 1.9 μg/mL for E. histolytica and 1.6 μg/mL for G. lamblia .Tiliroside showed antibacterial activity against all microorganisms tested with MIC values less than 0.7 mg/mL.Epicatechin was the most potent flavonoid on cholera toxin-induced diarrhea with IC 50 of 14.7 mg/kg. Abbreviations used: MECP: Methanol extract of C. pentadactylon .

Combined in vitro and in silico studies for the anticholinesterase activity and pharmacokinetics of coumarinyl thiazoles and oxadiazoles

NASA Astrophysics Data System (ADS)

Ibrar, Aliya; Khan, Ajmal; Ali, Majid; Sarwar, Rizwana; Mehsud, Saifullah; Farooq, Umar; Halimi, Syed M. A.; Khan, Imtiaz; Al-Harrasi, Ahmed

2018-03-01

In a continuation of our previous work for the exploration of novel enzyme inhibitors, two new coumarin-thiazole 6(a–o) and coumarin-oxadiazole 11(a–h) hybrids have been designed and synthesized. All the compounds were characterized by 1H- and 13C-NMR spectroscopy and elemental analysis. New hybrid analogues were evaluated against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) in order to know their potential for the prevention of Alzheimer’s disease (AD). In coumarinyl thiazole series, compound 6b was found as the most active member against AChE having IC50 value of 0.87 ± 0.09 µM, while the compound 6j revealed the same efficacy against BuChE with an IC50 value of 11.01 ± 3.37 µM. In case of coumarinyl oxadiazole series, 11a was turned out to be the lead candidate against AChE with an IC50 value of 6.07 ± 0.23 µM, whereas compound 11e was found significantly active against BuChE with an IC50 value of 0.15 ± 0.09 µM. To realize the binding interaction of these compounds with AChE and BuChE, the molecular docking studies were performed. Compounds from coumarinyl thiazole series with potent AChE activity (6b, 6h, 6i and 6k) were found to interact with AChE in the active site with MOE score of ‒10.19, ‒9.97, ‒9.68, and ‒11.03 Kcal.mol‒1, respectively. The major interactions include hydrogen bonding, π-π stacking with aromatic residues, and interaction through water bridging. The docking studies of coumarinyl oxadiazole derivatives 11(a-h) suggested that the compounds with high anti-butyrylcholinesterase activity (11e, 11a and 11b) provided MOE score of ‒9.9, ‒7.4 and ‒8.2 Kcal.mol‒1 respectively, with the active site of BuChE building π-π stacking with Trp82 and water bridged interaction.

Anti-inflammatory and antioxidant activities of ethanolic extract of aerial parts of Vernonia patula (Dryand.) Merr.

PubMed Central

Hira, Arpona; Dey, Shubhra Kanti; Howlader, Md. Sariful Islam; Ahmed, Arif; Hossain, Hemayet; Jahan, Ismet Ara

2013-01-01

Objective To investigate the inflammatory and antioxidant activities of ethanolic extract of aerial part of Vernonia patula (Dryand.) Merr (EAV). Methods The anti-inflammatory activity of EAV was studied using carrageenan and histamine-induced rat paw edema test at different doses (100, 200 and 400 mg/kg body weight). DPPH free radical scavenging, nitric oxide scavenging, reducing power and Fe2+ ion chelating ability were used for determining antioxidant activities. Results The EAV, at the dose of 400 mg/kg, showed a significant anti-inflammatory activity (P<0.01) both in the carrageenan and histamine-induced oedema test models in rats, showing 62.86% and 64.42% reduction in the paw volume comparable to that produced by the standard drug indomethacin (67.26% and 66.01%) at 5 h respectively. In DPPH free radical scavenging test, IC50 value for EAV was found fairly significant 36.59 µg/mL when compared to the IC50 value of the reference standards ascorbic acid 8.97 µg/mL. The IC50 values of the extract and ascorbic acid were 47.72 and 12.39 µg/mL, respectively in nitric oxide scavenging assay. The IC50 value of the EAV (33.59 µg/mL) as percentage of Fe2+ ion chelating ability was also found significant compared to that of EDTA (9.16 µg/mL). The maximum absorbance for reducing power assay was found to be 1.928 at 100 µg/mL when compared to 2.449 for standard ascorbic acid. The total phenolic content was 198.81 mg/g of gallic acid equivalent. Acute toxicity test showed that the plant might be safe for pharmacological uses up to a dose level of 3 200 mg/kg of body weight in rats. Conclusions Therefore, the obtained results suggest the acute anti-inflammatory and antioxidant activities of the EAV and thus provide the scientific basis for the traditional uses of this plant part as a remedy for inflammations. PMID:24075345

Pharmacological profile of CS-3150, a novel, highly potent and selective non-steroidal mineralocorticoid receptor antagonist.

PubMed

Arai, Kiyoshi; Homma, Tsuyoshi; Morikawa, Yuka; Ubukata, Naoko; Tsuruoka, Hiyoyuki; Aoki, Kazumasa; Ishikawa, Hirokazu; Mizuno, Makoto; Sada, Toshio

2015-08-15

The present study was designed to characterize the pharmacological profile of CS-3150, a novel non-steroidal mineralocorticoid receptor antagonist. In the radioligand-binding assay, CS-3150 inhibited (3)H-aldosterone binding to mineralocorticoid receptor with an IC50 value of 9.4nM, and its potency was superior to that of spironolactone and eplerenone, whose IC50s were 36 and 713nM, respectively. CS-3150 also showed at least 1000-fold higher selectivity for mineralocorticoid receptor over other steroid hormone receptors, glucocorticoid receptor, androgen receptor and progesterone receptor. In the reporter gene assay, CS-3150 inhibited aldosterone-induced transcriptional activation of human mineralocorticoid receptor with an IC50 value of 3.7nM, and its potency was superior to that of spironolactone and eplerenone, whose IC50s were 66 and 970nM, respectively. CS-3150 had no agonistic effect on mineralocorticoid receptor and did not show any antagonistic or agonistic effect on glucocorticoid receptor, androgen receptor and progesterone receptor even at the high concentration of 5μM. In adrenalectomized rats, single oral administration of CS-3150 suppressed aldosterone-induced decrease in urinary Na(+)/K(+) ratio, an index of in vivo mineralocorticoid receptor activation, and this suppressive effect was more potent and longer-lasting than that of spironolactone and eplerenone. Chronic treatment with CS-3150 inhibited blood pressure elevation induced by deoxycorticosterone acetate (DOCA)/salt-loading to rats, and this antihypertensive effect was more potent than that of spironolactone and eplerenone. These findings indicate that CS-3150 is a selective and highly potent mineralocorticoid receptor antagonist with long-lasting oral activity. This agent could be useful for the treatment of hypertension, cardiovascular and renal disorders. Copyright © 2015 Elsevier B.V. All rights reserved.

Comparative study of selective in vitro and in silico BACE1 inhibitory potential of glycyrrhizin together with its metabolites, 18α- and 18β-glycyrrhetinic acid, isolated from Hizikia fusiformis.

PubMed

Wagle, Aditi; Seong, Su Hui; Zhao, Bing Tian; Woo, Mi Hee; Jung, Hyun Ah; Choi, Jae Sue

2018-04-01

Hizikia fusiformis (Harvey) Okamura is a brown seaweed widely used in Korea and Japan, and it contains different therapeutically active constituents. In the present study, we investigated the activities of glycyrrhizin isolated from H. fusiformis, including its metabolites, 18α- and 18β-glycyrrhetinic acid against Alzheimer's disease (AD) via acetyl and butyrylcholinesterase and β-site amyloid precursor protein cleaving enzyme 1 (BACE1) inhibition. Among these three compounds, 18β-glycyrrhetinic acid (IC 50  = 8.93 ± 0.69 µM) demonstrated two fold potent activity against BACE1 compared to the positive control, quercetin (IC 50  = 20.18 ± 0.79 µM). Additionally, glycyrrhizin with an IC 50  value of 20.12 ± 1.87 µM showed similarity to quercetin, while 18α-glycyrrhetinic acid showed moderate activity (IC 50  = 104.35 ± 2.84 µM). A kinetic study revealed that glycyrrhizin and 18β-glycyrrhetinic acid were non-competitive and competitive inhibitiors of BACE1, demonstrated via K i values of 16.92 and 10.91 µM, respectively. Molecular docking simulation studies evidently revealed strong binding energy of these compounds for BACE1, indicating their high affinity and capacity for tighter binding to the active site of the enzyme. These data suggest that glycyrrhizin isolated from the edible seaweed, H. fusiformis and its metabolite, 18β-glycyrrhetinic acid demonstrated selective inhibitory activity against BACE1 to alleviate AD.

Characterization of Cladosporols from the Marine Algal-Derived Endophytic Fungus Cladosporium cladosporioides EN-399 and Configurational Revision of the Previously Reported Cladosporol Derivatives.

PubMed

Li, Hong-Lei; Li, Xiao-Ming; Mándi, Attila; Antus, Sándor; Li, Xin; Zhang, Peng; Liu, Yang; Kurtán, Tibor; Wang, Bin-Gui

2017-10-06

Four new cladosporol derivatives, cladosporols F-I (1-4), the known cladosporol C (5), and its new epimer, cladosporol J (6), were isolated and identified from the marine algal-derived endophytic fungus Cladosporium cladosporioides EN-399. Their structures were determined by detailed interpretation of NMR and MS data, and the absolute configurations were established on the basis of TDDFT-ECD and OR calculations. The configurational assignment of cladosporols F (1) and G (2) showed that the previously reported absolute configuration of cladosporol A and all the related cladosporols need to be revised from (4'R) to (4'S). Compounds 1-6 showed antibacterial activity against Escherichia coli, Micrococcus luteus, and Vibrio harveyi with MIC values ranging from 4 to 128 μg/mL. Compound 3 showed significant cytotoxicity against A549, Huh7, and LM3 cell lines with IC 50 values of 5.0, 1.0, and 4.1 μM, respectively, and compound 5 showed activity against H446 cell line with IC 50 value of 4.0 μM.

Synthesis and β-glucuronidase inhibitory activity of 2-arylquinazolin-4(3H)-ones.

PubMed

Khan, Khalid Mohammed; Saad, Syed Muhammad; Shaikh, Nimra Naveed; Hussain, Shafqat; Fakhri, Muhammad Imran; Perveen, Shahnaz; Taha, Muhammad; Choudhary, Muhammad Iqbal

2014-07-01

2-Arylquinazolin-4(3H)-ones 1-25 were synthesized by reacting anthranilamide with various benzaldehydes using CuCl2·2H2O as a catalyst in ethanol under reflux. Synthetic 2-arylquinazolin-4(3H)-ones 1-25 were evaluated for their β-glucuronidase inhibitory potential. A trend of inhibition IC50 against the enzyme in the range of 0.6-198.2μM, was observed and compared with the standard d-saccharic acid 1,4-lactone (IC50=45.75±2.16μM). Compounds 13, 19, 4, 12, 14, 22, 23, 25, 15, 8, 17, 11, 21, 1, 3, 18, 9, 2, and 24 with the IC50 values within the range of 0.6-44.0μM, indicated that the compounds have superior activity than the standard. The compounds showed no cytotoxic effects against PC-3 cells. A structure-activity relationship is established. Copyright © 2014 Elsevier Ltd. All rights reserved.

Minor oxygenated cannabinoids from high potency Cannabis sativa L.

PubMed

Ahmed, Safwat A; Ross, Samir A; Slade, Desmond; Radwan, Mohamed M; Khan, Ikhlas A; ElSohly, Mahmoud A

2015-09-01

Nine oxygenated cannabinoids were isolated from a high potency Cannabis sativa L. variety. Structure elucidation was achieved using spectroscopic techniques, including 1D and 2D NMR, HRMS and GC-MS. These minor compounds include four hexahydrocannabinols, four tetrahydrocannabinols, and one hydroxylated cannabinol, namely 9α-hydroxyhexahydrocannabinol, 7-oxo-9α-hydroxyhexa-hydrocannabinol, 10α-hydroxyhexahydrocannabinol, 10aR-hydroxyhexahydrocannabinol, Δ(9)-THC aldehyde A, 8-oxo-Δ(9)-THC, 10aα-hydroxy-10-oxo-Δ(8)-THC, 9α-hydroxy-10-oxo-Δ(6a,10a)-THC, and 1'S-hydroxycannabinol, respectively. The latter compound showed moderate anti-MRSa (IC50 10.0 μg/mL), moderate antileishmanial (IC50 14.0 μg/mL) and mild antimalarial activity against Plasmodium falciparum (D6 clone) and P. falciparum (W2 clone) with IC50 values of 3.4 and 2.3 μg/mL, respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

Hit-to-lead optimization of phenylsulfonyl hydrazides for a potent suppressor of PGE2 production: Synthesis, biological activity, and molecular docking study.

PubMed

Kim, Minju; Lee, Sunhoe; Park, Eun Beul; Kim, Kwang Jong; Lee, Hwi Ho; Shin, Ji-Sun; Fischer, Katrin; Koeberle, Andreas; Werz, Oliver; Lee, Kyung-Tae; Lee, Jae Yeol

2016-01-01

Preliminary hit-to-lead optimization of a novel series of phenylsulfonyl hydrazide derivatives, which were derived from the high throughput screening hit compound 1 (IC50=5700nM against PGE2 production), for a potent suppressor of PGE2 production is described. Subsequent optimization led to the identification of the potent lead compound 8n with IC50 values of 4.5 and 6.9nM, respectively, against LPS-induced PGE2 production and NO production in RAW 264.7 macrophage cells. In addition, 8n was about 30- and >150-fold more potent against mPGES-1 enzyme in a cell-free assay (IC50=70nM) than MK-886 and hit compound 1, respectively. Molecular docking suggests that compound 8n could inhibit PGE2 production by blocking the PGH2 binding site of human mPGES-1 enzyme. Copyright © 2015 Elsevier Ltd. All rights reserved.

Specific and highly efficient condensation of GC and IC DNA by polyaza pyridinophane derivatives.

PubMed

Stojković, Marijana Radić; Gonzalez-Garcia, Jorge; Šupljika, Filip; Galiana-Rosello, Cristina; Guijarro, Lluis; Gazze, Salvatore A; Francis, Lewis W; Piantanida, Ivo; Garcia-Espana, Enrique

2018-04-01

Two bis-polyaza pyridinophane derivatives and their monomeric reference compounds revealed strong interactions with ds-DNA and RNA. The bis-derivatives show a specific condensation of GC- and IC-DNA, which is almost two orders of magnitude more efficient than the well-known condensation agent spermine. The type of condensed DNA was identified as ψ-DNA, characterized by the exceptionally strong CD signals. At variance to the almost silent AT(U) polynucleotides, these strong CD signals allow the determination of GC-condensates at nanomolar nucleobase concentrations. Detailed thermodynamic characterisation by ITC reveals significant differences between the DNA binding of the bis-derivative compounds (enthalpy driven) and that of spermine and of their monomeric counterparts (entropy driven). Atomic force microscopy confirmed GC-DNA compaction by the bis-derivatives and the formation of toroid- and rod-like structures responsible for the ψ-type pattern in the CD spectra. Copyright © 2017 Elsevier B.V. All rights reserved.

Synthesis and in vitro study of benzofuran hydrazone derivatives as novel alpha-amylase inhibitor.

PubMed

Taha, Muhammad; Shah, Syed Adnan Ali; Imran, Syahrul; Afifi, Muhammad; Chigurupati, Sridevi; Selvaraj, Manikandan; Rahim, Fazal; Ullah, Hayat; Zaman, Khalid; Vijayabalan, Shantini

2017-12-01

The α-amylase acts as attractive target to treat type-2 diabetes mellitus. Therefore in discovering a small molecule as α-amylase inhibitor, we have synthesized benzofuran carbohydrazide analogs (1-25), characterized through different spectroscopic techniques such as 1 HNMR and EI-MS. All screened analog shows good α-amylase inhibitory potentials with IC 50 value ranging between 1.078±0.19 and 2.926±0.05µM when compared with acarbose having IC 50 =0.62±0.22µM. Only nine analogs among the series such as analogs 3, 5, 7, 8, 10, 12, 21, 23 and 24 exhibit good inhibitory potential with IC 50 values 1.644±0.128, 1.078±0.19, 1.245±0.25, 1.843±0.19, 1.350±0.24, 1.629±0.015, 1.353±0.232, 1.359±0.119 and 1.488±0.07µM when compare with standard drug acarbose. All other analogs showed good to moderate α-amylase inhibitory potentials. The SAR study was conducted on the basis of substituent difference at the phenyl ring. The binding interaction between analogs and active site of enzyme was confirmed by docking studies. Copyright © 2017 Elsevier Inc. All rights reserved.

Efficacy of carbosilane dendrimers with an antiretroviral combination against HIV-1 in the presence of semen-derived enhancer of viral infection.

PubMed

García-Broncano, Pilar; Ceña-Diez, Rafael; de la Mata, Francisco J; Gómez, Rafael; Resino, Salvador; Muñoz-Fernández, M Ángeles

2017-09-15

Amyloid fibrils, which are present in semen, were considered to be a cause of topical vaginal gel ineffectiveness in vivo after microbicides failed as HIV-1 prophylaxis. Therefore, it was necessary to determine whether a dendrimer was suitable for further evaluation in an in vitro model of semen-enhanced viral infection (SEVI). We demonstrated that SEVI in TZM.bl cell cultures increased the infectivity of R5-HIV-1 NL(AD8) , pTHRO.c and pCH058.c isolates, causing higher IC 50 values for two polyanionic carbosilane dendrimers, G2-STE16 and G3-S16. However, both dendrimers maintained protection rates of 90% at non-toxic concentrations. When dendrimers were combined with Tenofovir/Maraviroc (TDF/MVC), the anti-HIV-1 effect remained at a minimum IC 50 increase between 1- and 7-fold in the presence of amyloid fibrils. In peripheral blood mononuclear cells (PBMC), IC 50 values were slightly influenced by the presence of semen. In brief, dendrimers combined with antiretrovirals showed a synergistic effect. This result plays a crucial role in new microbicide formulations, as it overcomes the negative effects of amyloid fibrils. Copyright © 2017 Elsevier B.V. All rights reserved.

Identification of flavonoids and flavonoid rhamnosides from Rhododendron mucronulatum for. albiflorum and their inhibitory activities against aldose reductase.

PubMed

Mok, So-Youn; Lee, Sanghyun

2013-01-15

To investigate the therapeutic potential of compounds from natural sources, Rhododendron mucronulatum for. albiflorum flowers (RMAF) and R. mucronulatum flowers (RMF) were tested for inhibition of aldose reductase (AR). The methanol extracts of RMAF and RMF exhibited AR inhibitory activities (IC(50) values 1.07 and 1.29 μg/mL, respectively). The stepwise polarity fractions of RMAF were tested for in vitro inhibition of AR from rat lenses. Of these, the ethyl acetate (EtOAc) fraction exhibited AR inhibitory activity (IC(50) 0.15 μg/mL). A chromatography of the active EtOAc fraction of RMAF led to the isolation of six flavonoids, which were identified by spectroscopic analysis as kaempferol (1), afzelin (2), quercetin (3), quercitrin (4), myricetin (5) and myricitrin (6). Compounds 1-6 exhibited high AR inhibitory activity, with IC(50) values of 0.79, 0.31, 0.48, 0.13, 11.92 and 2.67 μg/mL, respectively. HPLC/UV analysis revealed that the major flavonoids of RMAF and RMF are quercitrin (4) and myricitrin (6). Our results suggest that RMAF containing these six flavonoids could be a useful natural source in the development of a novel AR inhibitory agent against diabetic complications. Copyright © 2012 Elsevier Ltd. All rights reserved.

Anti-proliferation and Apoptosis Induction of Aqueous Leaf Extract of Carica papaya L. on Human Breast Cancer Cells MCF-7.

PubMed

Zuhrotun Nisa, Fatma; Astuti, Mary; Murdiati, Agnes; Mubarika Haryana, Sofia

2017-01-01

Breast cancer is the most frequently diagnosed cancer in women. Chemotherapy is the main method of breast cancer treatment but there are side effects. Carica papaya leaves is vegetable foods consumed by most people of Indonesia have potential as anticancer. The aim of this study was to investigate anti-proliferative and apoptotic induced effect of aqueous papaya leaves extracts on human breast cancer cell lines MCF-7. Inhibitory on cell proliferation was measured by MTT assay while apoptosis induction was measured using Annexin V. The results showed that papaya leaf can inhibit the proliferation of human breast cancer cells MCF-7 with IC50 in 1319.25 μg mL-1. The IC50 values of papaya leaf extract was higher than the IC50 value quercetin and doxorubicin. Papaya leaf extract can also induce apoptosis of breast cancer cells MCF-7 about 22.54% for concentration 659.63 μg mL-1 and about 20.73% for concentration 329.81 μg mL-1. The percentage of cell apoptosis of papaya leaf extract lower than doxorubicin but higher than quercetin. This study indicated that papaya leaf extract have potential as anticancer through mechanism anti-proliferation and apoptosis induction.

Antioxidant activities of different solvent extracts of Piper retrofractum Vahl. using DPPH assay

NASA Astrophysics Data System (ADS)

Jadid, Nurul; Hidayati, Dewi; Hartanti, Sylviana Rosyda; Arraniry, Byan Arasyi; Rachman, Rizka Yuanita; Wikanta, Wiwi

2017-06-01

Piper retrofractum Vahl., which belongs to the family Piperaceae, is geographically dispersed in tropical region including Indonesia. They are well-known spice possessing high medicinal properties. This study aimed to determine the antioxidant activity of P. retrofractum fruit, extracted with different solvents (methanol, ethyl acetate, n-hexane) using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. This research was carried out using different concentrations of methanol, ethyl acetate, and n-hexane extracts, (0, 5, 15, 30, 45, 60 ppm). Ascorbic acid was also used as positive antioxidant control. The percentage of inhibition and IC50 were measured. The results showed that the DPPH free radicals were scavenged by all plant extracts in a concentration dependent manner. Moreover, the IC50 values for DPPH radicals with methanol, ethyl acetate and n-hexane extract of the P. retrofractum Vahl. were found to be 101.74; 66.12 and 57.66 ppm, respectively. Interestingly, the IC50 value of n-hexane extract (57.66 ppm) was lower than ascorbic acid (66.12 ppm), indicating that n-hexane extract was a more potent scavenger of free radicals than methanol and ethyl acetate extracts. Taken together, our results suggested that n-hexane extract of P. Retrofractum Vahl. might contain potential antioxidant compounds.

Automated and manual patch clamp data of human induced pluripotent stem cell-derived dopaminergic neurons.

PubMed

Franz, Denise; Olsen, Hervør Lykke; Klink, Oliver; Gimsa, Jan

2017-04-25

Human induced pluripotent stem cells can be differentiated into dopaminergic neurons (Dopa.4U). Dopa.4U neurons expressed voltage-gated Na V and K V channels and showed neuron-like spontaneous electrical activity. In automated patch clamp measurements with suspended Dopa.4U neurons, delayed rectifier K + current (delayed K V ) and rapidly inactivating A-type K + current (fast K V ) were identified. Examination of the fast K V current with inhibitors yielded IC 50 values of 0.4 mM (4-aminopyridine) and 0.1 mM (tetraethylammonium). In manual patch clamp measurements with adherent Dopa.4U neurons, fast K V current could not be detected, while the delayed K V current showed an IC 50 of 2 mM for 4-aminopyridine. The Na V channels in adherent and suspended Dopa.4U neurons showed IC 50 values for tetrodotoxin of 27 and 2.9 nM, respectively. GABA-induced currents that could be observed in adherent Dopa.4U neurons could not be detected in suspended cells. Application of current pulses induced action potentials in approx. 70 % of the cells. Our results proved the feasibility of automated electrophysiological characterization of neuronal cells.

N-Desmethylclozapine, Fluoxetine, and Salmeterol Inhibit Postentry Stages of the Dengue Virus Life Cycle.

PubMed

Medigeshi, Guruprasad R; Kumar, Rinki; Dhamija, Ekta; Agrawal, Tanvi; Kar, Meenakshi

2016-11-01

Around 10,000 people die each year due to severe dengue disease, and two-thirds of the world population lives in a region where dengue disease is endemic. There has been remarkable progress in dengue virus vaccine development; however, there are no licensed antivirals for dengue disease, and none appear to be in clinical trials. We took the approach of repositioning approved drugs for anti-dengue virus activity by screening a library of pharmacologically active compounds. We identified N-desmethylclozapine, fluoxetine hydrochloride, and salmeterol xinafoate as dengue virus inhibitors based on reductions in the numbers of infected cells and viral titers. Dengue virus RNA levels were diminished in inhibitor-treated cells, and this effect was specific to dengue virus, as other flaviviruses, such as Japanese encephalitis virus and West Nile virus, or other RNA viruses, such as respiratory syncytial virus and rotavirus, were not affected by these inhibitors. All three inhibitors specifically inhibited dengue virus replication with 50% inhibitory concentrations (IC 50 s) in the high-nanomolar range. Estimation of negative-strand RNA intermediates and time-of-addition experiments indicated that inhibition was occurring at a postentry stage, most probably at the initiation of viral RNA replication. Finally, we show that inhibition is most likely due to the modulation of the endolysosomal pathway and induction of autophagy. Copyright © 2016 Medigeshi et al.

AshwaMAX and Withaferin A inhibits gliomas in cellular and murine orthotopic models

PubMed Central

Pohling, Christoph; Natarajan, Arutselvan; Witney, Timothy H.; Kaur, Jasdeep; Xu, Lingyun; Gowrishankar, Gayatri; D’Souza, Aloma L; Murty, Surya; Schick, Sophie; Chen, Liyin; Wu, Nicholas; Khaw, Phoo; Mischel, Paul; Abbasi, Taher; Usmani, Shahabuddin; Mallick, Parag

2017-01-01

Glioblastoma multiforme (GBM) is an aggressive, malignant cancer Johnson and O’Neill (J Neurooncol 107: 359–364, 2012). An extract from the winter cherry plant (Withania somnifera), AshwaMAX, is concentrated (4.3 %) for Withaferin A; a steroidal lactone that inhibits cancer cells Vanden Berghe et al. (Cancer Epidemiol Biomark Prev 23: 1985–1996, 2014). We hypothesized that AshwaMAX could treat GBM and that bioluminescence imaging (BLI) could track oral therapy in orthotopic murine models of glioblastoma. Human parietal-cortical glioblastoma cells (GBM2, GBM39) were isolated from primary tumors while U87-MG was obtained commercially. GBM2 was transduced with lentiviral vectors that express Green Fluorescent Protein (GFP)/firefly luciferase fusion proteins. Mutational, expression and proliferative status of GBMs were studied. Intracranial xenografts of glioblastomas were grown in the right frontal regions of female, nude mice (n = 3–5 per experiment). Tumor growth was followed through BLI. Neurosphere cultures (U87-MG, GBM2 and GBM39) were inhibited by AshwaMAX at IC50 of 1.4, 0.19 and 0.22 μM equivalent respectively and by Withaferin A with IC50 of 0.31, 0.28 and 0.25 μM respectively. Oral gavage, every other day, of AshwaMAX (40 mg/kg per day) significantly reduced bioluminescence signal (n = 3 mice, p < 0.02, four parameter non-linear regression analysis) in preclinical models. After 30 days of treatment, bioluminescent signal increased suggesting onset of resistance. BLI signal for control, vehicle-treated mice increased and then plateaued. Bioluminescent imaging revealed diffuse growth of GBM2 xenografts. With AshwaMAX, GBM neurospheres collapsed at nanomolar concentrations. Oral treatment studies on murine models confirmed that AshwaMAX is effective against orthotopic GBM. AshwaMAX is thus a promising candidate for future clinical translation in patients with GBM. PMID:26650066

AshwaMAX and Withaferin A inhibits gliomas in cellular and murine orthotopic models.

PubMed

Chang, Edwin; Pohling, Christoph; Natarajan, Arutselvan; Witney, Timothy H; Kaur, Jasdeep; Xu, Lingyun; Gowrishankar, Gayatri; D'Souza, Aloma L; Murty, Surya; Schick, Sophie; Chen, Liyin; Wu, Nicholas; Khaw, Phoo; Mischel, Paul; Abbasi, Taher; Usmani, Shahabuddin; Mallick, Parag; Gambhir, Sanjiv S

2016-01-01

Glioblastoma multiforme (GBM) is an aggressive, malignant cancer Johnson and O'Neill (J Neurooncol 107: 359-364, 2012). An extract from the winter cherry plant (Withania somnifera ), AshwaMAX, is concentrated (4.3 %) for Withaferin A; a steroidal lactone that inhibits cancer cells Vanden Berghe et al. (Cancer Epidemiol Biomark Prev 23: 1985-1996, 2014). We hypothesized that AshwaMAX could treat GBM and that bioluminescence imaging (BLI) could track oral therapy in orthotopic murine models of glioblastoma. Human parietal-cortical glioblastoma cells (GBM2, GBM39) were isolated from primary tumors while U87-MG was obtained commercially. GBM2 was transduced with lentiviral vectors that express Green Fluorescent Protein (GFP)/firefly luciferase fusion proteins. Mutational, expression and proliferative status of GBMs were studied. Intracranial xenografts of glioblastomas were grown in the right frontal regions of female, nude mice (n = 3-5 per experiment). Tumor growth was followed through BLI. Neurosphere cultures (U87-MG, GBM2 and GBM39) were inhibited by AshwaMAX at IC50 of 1.4, 0.19 and 0.22 µM equivalent respectively and by Withaferin A with IC50 of 0.31, 0.28 and 0.25 µM respectively. Oral gavage, every other day, of AshwaMAX (40 mg/kg per day) significantly reduced bioluminescence signal (n = 3 mice, p < 0.02, four parameter non-linear regression analysis) in preclinical models. After 30 days of treatment, bioluminescent signal increased suggesting onset of resistance. BLI signal for control, vehicle-treated mice increased and then plateaued. Bioluminescent imaging revealed diffuse growth of GBM2 xenografts. With AshwaMAX, GBM neurospheres collapsed at nanomolar concentrations. Oral treatment studies on murine models confirmed that AshwaMAX is effective against orthotopic GBM. AshwaMAX is thus a promising candidate for future clinical translation in patients with GBM.

NOSH-aspirin (NBS-1120), a novel nitric oxide- and hydrogen sulfide-releasing hybrid is a potent inhibitor of colon cancer cell growth in vitro and in a xenograft mouse model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chattopadhyay, Mitali; Kodela, Ravinder; Olson, Kenneth R.

Highlights: Black-Right-Pointing-Pointer NOSH-aspirin is the first dual acting NO and H{sub 2}S releasing hybrid. Black-Right-Pointing-Pointer Its IC{sub 50} for cell growth inhibition is in the low nano-molar range. Black-Right-Pointing-Pointer Structure-activity studies show that the sum of the parts does not equal the whole. Black-Right-Pointing-Pointer NOSH-aspirin reduced tumor growth by 85% in mice bearing a colon cancer xenograft. -- Abstract: Nonsteroidal anti-inflammatory drugs (NSAIDs) are prototypical anti-cancer agents. However, their long-term use is associated with adverse gastrointestinal effects. Recognition that endogenous gaseous mediators, nitric oxide (NO) and hydrogen sulfide (H{sub 2}S) can increase mucosal defense mechanisms has led to the developmentmore » of NO- and H{sub 2}S-releasing NSAIDs with increased safety profiles. Here we report on a new hybrid, NOSH-aspirin, which is an NO- and H{sub 2}S-releasing agent. NOSH-aspirin inhibited HT-29 colon cancer growth with IC{sub 50}s of 45.5 {+-} 2.5, 19.7 {+-} 3.3, and 7.7 {+-} 2.2 nM at 24, 48, and 72 h, respectively. This is the first NSAID based agent with such high degree of potency. NOSH-aspirin inhibited cell proliferation, induced apoptosis, and caused G{sub 0}/G{sub 1} cell cycle block. Reconstitution and structure-activity studies representing a fairly close approximation to the intact molecule showed that NOSH-aspirin was 9000-fold more potent than the sum of its parts towards growth inhibition. NOSH-aspirin inhibited ovine COX-1 more than ovine COX-2. NOSH-ASA treatment of mice bearing a human colon cancer xenograft caused a reduction in volume of 85%. Taken together, these results demonstrate that NOSH-aspirin has strong anti-cancer potential and merits further evaluation.« less

Cytotoxic withanolides from Physalis angulata L.

PubMed

He, Qing-Ping; Ma, Lei; Luo, Jie-Ying; He, Fu-Yuan; Lou, Li-Guang; Hu, Li-Hong

2007-03-01

Four new withanolides, physagulins L-O (1-4), were isolated from the MeOH extract of the aerial parts of Physalis angulata L. (Solanaceae), together with seven known withanolides, compounds 5-11. Their structures were determined by spectroscopic techniques, including 1H-, 13C-NMR (DEPT), and 2D-NMR (HMBC, HMQC, 1H,1H-COSY, NOESY) experiments, as well as by HR-MS. All eleven compounds were tested for their antiproliferative activities towards human colorectal-carcinoma (HCT-116) and human non-small-cell lung-cancer (NCI-H460) cells. Compound 5 exhibited the highest anticancer activity against the HCT-116 cell line, with an IC50 value of 1.64+/-0.06 microM. Compound 9 exhibited the highest cytotoxicity towards the NCI-H460 cell line, with an IC50 value of 0.43+/-0.02 microM.

Fucoidan cytotoxicity against human breast cancer T47D cell line increases with higher level of sulfate ester group

NASA Astrophysics Data System (ADS)

Saepudin, Endang; Alfita Qosthalani, Fildzah; Sinurat, Ellya

2018-01-01

The anticancer activity of different sulfate ester group content in different molecular weight was examined. The anticancer activity was achieved in vitro on human breast cancer T47D cell line. Fucoidan with lower molecular weight (5.79 kDa) tends to have lower sulfate ester group content (8.69%) and resulted in higher IC50 value (184.22 μg/mL). While fucoidan with higher molecular weight (785.12 kDa) tends to have higher sulfate level (18.63%) and achieved lower IC50 value (75.69 μg/mL). The result showed that in order to maintain fucoidan cytotoxic activity against human breast cancer T47D cell line, the sulfate content should be remain high. Keywords: fucoidan, sulfate ester group, human breast cancer

Antiviral flavonoids from the seeds of Aesculus chinensis.

PubMed

Wei, Feng; Ma, Shuang-Cheng; Ma, Lin-Yun; But, Paul Pui-Hay; Lin, Rui-Chao; Khan, Ikhlas A

2004-04-01

A bioassay-guided fractionation of an ethanol extract of the seeds of Aesculus chinensis led to the isolation of two new flavanoids (1 and 2), along with eight known ones (3-10). The structures of the new compounds were elucidated by spectroscopic methods including 2D NMR. All compounds were tested for antiviral activity against respiratory syncytial virus (RSV), parainfluenza virus type 3 (PIV 3), and influenza virus type A (Flu A). Compounds 1, 2, and 6 showed significant antiviral activities against RSV with IC(50) values of 4.5, 6.7, and 4.1 microg/mL and selective index (SI) values of 15.8, 32, and 63.8, respectively. Compound 8 demonstrated significant antiviral activity against Flu A with an IC(50) of 24.5 microg/mL and a SI of 16.0, respectively.

Synthesis and biological evaluation of novel tacrine derivatives and tacrine-coumarin hybrids as cholinesterase inhibitors.

PubMed

Hamulakova, Slavka; Janovec, Ladislav; Hrabinova, Martina; Spilovska, Katarina; Korabecny, Jan; Kristian, Pavol; Kuca, Kamil; Imrich, Jan

2014-08-28

A series of novel tacrine derivatives and tacrine-coumarin heterodimers were designed, synthesized, and biologically evaluated for their potential inhibitory effect on both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). Of these compounds, tacrine-coumarin heterodimer 7c and tacrine derivative 6b were found to be the most potent inhibitors of human AChE (hAChE), demonstrating IC50 values of 0.0154 and 0.0263 μM. Ligands 6b, 6c, and 7c exhibited the highest levels of inhibitory activity against human BuChE (hBuChE), demonstrating IC50 values that range from 0.228 to 0.328 μM. Docking studies were performed in order to predict the binding modes of compounds 6b and 7c with hAChE/hBuChE.

In Vitro Sensitivity of Cutaneous Leishmania Promastigote Isolates Circulating in French Guiana to a Set of Drugs

PubMed Central

Ginouvès, Marine; Simon, Stéphane; Nacher, Mathieu; Demar, Magalie; Carme, Bernard; Couppié, Pierre; Prévot, Ghislaine

2017-01-01

Anti-leishmaniasis drug resistance is a common problem worldwide. The aim of this study was to inventory the general in vitro level of sensitivity of Leishmania isolates circulating in French Guiana and to highlight potential in vitro pentamidine-resistant isolates. This sensitivity study was conducted on 36 patient-promastigote isolates for seven drugs (amphotericin B, azithromycin, fluconazole, meglumine antimoniate, miltefosine, paromomycin, and pentamidine) using the Cell Counting Kit-8 viability test. The IC50 values obtained were heterogeneous. One isolate exhibited high IC50 values for almost all drugs tested. Pentamidine, which is the first-line treatment in French Guiana, showed efficacy at very low doses (mean of 0.0038 μg/mL). The concordance of the in vitro pentamidine results with the patients' clinical outcomes was 94% (K = 0.82). PMID:28167598

Bioactive steroids and sorbicillinoids isolated from the endophytic fungus Trichoderma sp. Xy24.

PubMed

Zhao, Jin-Lian; Zhang, Min; Liu, Ji-Mei; Tan, Zhen; Chen, Ri-Dao; Xie, Ke-Bo; Dai, Jun-Gui

2017-10-01

A new steroid glucoside (1), along with nine known steroids (2-10) and four known sorbicillinoids (11-14), were isolated from the endophytic fungus Trichoderma sp. Xy24. Their structures were elucidated on the basis of spectroscopic data analyses and by comparison with reported data. Compounds 3, 5-7, 9, 10, and 13 exhibited significant inhibitory effects on HIV-1 virus with IC 50 values ranging 1.9-9.3 μM; compounds 10, 13, and 14 showed potent inhibitory activity on LPS-induced NO production in BV2 microglia cells with inhibitory rates of 108.2, 100, and 75.1% at 10 μM, respectively. In addition, compound 10 displayed moderate cytotoxicity against BCG823 and HePG2 cell lines with IC 50 values of 11.1 and 17.7 μM, respectively.

The constituents and their bioactivities of Houttuynia cordata.

PubMed

Chou, Shu-Chen; Su, Chung-Ren; Ku, Yuh-Chi; Wu, Tian-Shung

2009-11-01

Chemical investigation on the whole plant of Houttuynia cordata has resulted in the isolation of two new compounds, named as houttuynoside A (1) and houttuynamide A (2), together with thirty-eight known compounds. The structures of 1 and 2 were elucidated on the basis of spectroscopic analysis. In the inhibitory effects on herpes simplex virus type 1 (HSV-1) assay, norcepharadione B (10) showed good inhibitory activity against the replication of HSV-1. In addition, the antioxidant and antityrosinase activities of some isolated compounds were also evaluated. Among these compounds, quercitrin (25) and quercetin-3-O-beta-D-galactopyranoside (26) showed excellent 2,2-diphenyl-1-picrylhydrazyl radical-scavenging property with IC50 values of 31 and 63 microM, respectively. Cepharadione B (9) exhibited strong tyrosinase inhibitory activity with an IC50 value of 170 microM.

Loddigesiinols G-J: α-glucosidase inhibitors from Dendrobium loddigesii.

PubMed

Lu, Yu; Kuang, Ming; Hu, Gu-Ping; Wu, Rui-Bo; Wang, Jun; Liu, Lan; Lin, Yong-Cheng

2014-06-23

Four new polyphenols, loddigesiinols G-J (compounds 1-4) and a known compound, crepidatuol B (5), were isolated from the stems of Dendrobium loddigesii that have long been used in Traditional Chinese Medicine and have recently been used to treat type 2 diabetes. Compounds 1-5 structures were elucidated based on spectroscopic analysis. The absolute configurations of compounds 1-4 were determined using theoretical calculations of electronic circular dichroism (ECD), and the absolute configuration of compound 5 was determined by a comparison of the experimental ECD spectra and the literature data. Compounds 1-5 are strong inhibitors of α-glucosidase, with IC50 values of 16.7, 10.9, 2.7, 3.2, and 18.9 μM, respectively. Their activities were significantly stronger than trans-resveratrol as a positive control (IC50 values of 27.9 μM).

Novel angiotensin I-converting enzyme inhibitory peptides isolated from Alcalase hydrolysate of mung bean protein.

PubMed

Li, Guan-Hong; Wan, Ju-Zhen; Le, Guo-Wei; Shi, Yong-Hui

2006-08-01

Mung bean protein isolates were hydrolyzed for 2 h by Alcalase. The generated hydrolysate showed angiotensin I-converting enzyme (ACE) inhibitory activity with the IC(50) value of 0.64 mg protein/ml. Three kinds of novel ACE inhibitory peptides were isolated from the hydrolysate by Sephadex G-15 and reverse-phase high performance liquid chromatography (RP-HPLC). These peptides were identified by amino acid composition analysis and matrix assisted-laser desorption/ionization time-of-flight tandem mass spectrometry (MALDI-TOF MS/MS), as Lys-Asp-Tyr-Arg-Leu, Val-Thr-Pro-Ala-Leu-Arg and Lys-Leu-Pro-Ala-Gly-Thr-Leu-Phe with the IC(50) values of 26.5 microM, 82.4 microM and 13.4 microM, respectively. Copyright (c) 2006 European Peptide Society and John Wiley & Sons, Ltd.

In vitro 5-lipoxygenase and anti-oxidant activities of South African medicinal plants commonly used topically for skin diseases.

PubMed

Frum, Y; Viljoen, A M

2006-01-01

An investigation was undertaken to determine the possible mechanisms of action of medicinal plants used for dermatological pathologies. A total of 14 plant species were selected from the readily available ethnobotanical literature. 5-Lipoxygenase and DPPH (2,2-diphenyl-1-picrylhydrazyl) assays were used to determine the anti-inflammatory activity and the anti-oxidant activity of selected medicinal plants, respectively. Both aqueous and methanol extracts were tested. Among the plants screened, four species (Croton sylvaticus, Warburgia salutaris, Pentanisia prunelloides, and Melianthus comosus) displayed promising 5-lipoxygenase inhibitory activity with IC(50) values <61 ppm. A large number of plants exhibited significant anti-oxidant activities with IC(50) values between 5.27 and 83.36 ppm. Aqueous extracts of M. comosus exhibited the most potent anti-inflammatory and anti-oxidant activity.

Thiazoline peptides and a tris-phenethyl urea from Didemnum molle with anti-HIV activity.

PubMed

Lu, Zhenyu; Harper, Mary Kay; Pond, Christopher D; Barrows, Louis R; Ireland, Chris M; Van Wagoner, Ryan M

2012-08-24

As part of our screening for anti-HIV agents from marine invertebrates, the MeOH extract of Didemnum molle was tested and showed moderate in vitro anti-HIV activity. Bioassay-guided fractionation of a large-scale extract allowed the identification of two new cyclopeptides, mollamides E and F (1 and 2), and one new tris-phenethyl urea, molleurea A (3). The absolute configurations were established using the advanced Marfey's method. The three compounds were evaluated for anti-HIV activity in both an HIV integrase inhibition assay and a cytoprotective cell-based assay. Compound 2 was active in both assays with IC(50) values of 39 and 78 μM, respectively. Compound 3 was active only in the cytoprotective cell-based assay, with an IC(50) value of 60 μM.

High-throughput, 384-well, LC-MS/MS CYP inhibition assay using automation, cassette-analysis technique, and streamlined data analysis.

PubMed

Halladay, Jason S; Delarosa, Erlie Marie; Tran, Daniel; Wang, Leslie; Wong, Susan; Khojasteh, S Cyrus

2011-08-01

Here we describe a high capacity and high-throughput, automated, 384-well CYP inhibition assay using well-known HLM-based MS probes. We provide consistently robust IC(50) values at the lead optimization stage of the drug discovery process. Our method uses the Agilent Technologies/Velocity11 BioCel 1200 system, timesaving techniques for sample analysis, and streamlined data processing steps. For each experiment, we generate IC(50) values for up to 344 compounds and positive controls for five major CYP isoforms (probe substrate): CYP1A2 (phenacetin), CYP2C9 ((S)-warfarin), CYP2C19 ((S)-mephenytoin), CYP2D6 (dextromethorphan), and CYP3A4/5 (testosterone and midazolam). Each compound is incubated separately at four concentrations with each CYP probe substrate under the optimized incubation condition. Each incubation is quenched with acetonitrile containing the deuterated internal standard of the respective metabolite for each probe substrate. To minimize the number of samples to be analyzed by LC-MS/MS and reduce the amount of valuable MS runtime, we utilize timesaving techniques of cassette analysis (pooling the incubation samples at the end of each CYP probe incubation into one) and column switching (reducing the amount of MS runtime). Here we also report on the comparison of IC(50) results for five major CYP isoforms using our method compared to values reported in the literature.

Physalins V-IX, 16,24-cyclo-13,14-seco withanolides from Physalis angulata and their antiproliferative and anti-inflammatory activities.

PubMed

Sun, Cheng-Peng; Qiu, Chong-Yue; Zhao, Feng; Kang, Ning; Chen, Li-Xia; Qiu, Feng

2017-06-22

Five new physalins, including a novel 1,10-seco one, physalin V (1), a tricarboxylic acid cycle one, physalin VIII (5), a rare 11,15-cyclo one, physalin IX (6), and two new ones, physalins VI (2) and VII (4) were isolated from stems and leaves of Physalis angulata together with eleven known analogues (3 and 7-16). Their structures were established by MS, IR, UV, and NMR spectroscopic analysis, together with the X-ray diffraction analysis of neophysalin, physalin P (12), and the structure of physalin D 1 (3) has been revised here. These isolated compounds were evaluated for their antiproliferative activities against human cancer cells (C4-2B, 22Rv1, 786-O, A-498, ACHN, and A375-S2) and inhibitory effects on nitric oxide production. Compounds 9 and 10 showed antiproliferative activities against all tested human cancer cells with IC 50 values of 0.24-3.17 μM. Compounds 1, 3, 4, 9, 10, 13, 14, and 16 exhibited inhibitory activities against NO production. The IC 50 values of compounds 9, 10, 13, and 16 were between 0.32 and 4.03 μM, while compounds 1, 3, 4, and 14 had IC 50 values of 12.83-34.19 μM. Herein, plausible biosynthetic pathways for rare structures 1 and 6 and structure-activity relationships on the inhibition of NO production for all isolated compounds are discussed.

Synthesis, β-haematin inhibition, and in vitro antimalarial testing of isocryptolepine analogues: SAR study of indolo[3,2-c]quinolines with various substituents at C2, C6, and N11.

PubMed

Wang, Ning; Wicht, Kathryn J; Imai, Kento; Wang, Ming-Qi; Anh Ngoc, Tran; Kiguchi, Ryo; Kaiser, Marcel; Egan, Timothy J; Inokuchi, Tsutomu

2014-05-01

A series of indolo[3,2-c]quinolines were synthesized by modifying the side chains of the ω-aminoalkylamines at the C6 position and introducing substituents at the C2 position, such as F, Cl, Br, Me, MeO and NO2, and a methyl group at the N11 position for an SAR study. The in vitro antiplasmodial activities of the derivative agents against two different strains (CQS: NF54 and CQR: K1) and the cytotoxic activity against normal L6 cells were evaluated. The test results showed that compounds 6k and 6l containing the branched methyl groups of 3-aminopropylamino at C6 with a Cl atom at C2 exhibited a very low cytotoxicity with IC50 values above 4000 nM, high antimalarial activities with IC50 values of about 11 nM for CQS (NF54), IC50 values of about 17 nM for CQR (K1), and RI resistance indices of 1.6. Furthermore, the compounds were tested for β-haematic inhibition, and QSAR revealed an interesting linear correlation between the biological activity of CQS (NF54) and three contributing factors, namely solubility, hydrophilic surface area, and β-haematin inhibition for this series. In vivo testing of 6l showed a reduction in parasitaemia on day 4 with an activity of 38%. Copyright © 2014 Elsevier Ltd. All rights reserved.

Monoamine oxidase inhibitory activities of heterocyclic chalcones.

PubMed

Minders, Corné; Petzer, Jacobus P; Petzer, Anél; Lourens, Anna C U

2015-11-15

Studies have shown that natural and synthetic chalcones (1,3-diphenyl-2-propen-1-ones) possess monoamine oxidase (MAO) inhibition activities. Of particular importance to the present study is a report that a series of furanochalcones acts as MAO-B selective inhibitors. Since the effect of heterocyclic substitution, other than furan (and more recently thiophene, piperidine and quinoline) on the MAO inhibitory properties of the chalcone scaffold remains unexplored, the aim of this study was to synthesise and evaluate further heterocyclic chalcone analogues as inhibitors of the human MAOs. For this purpose, heterocyclic chalcone analogues that incorporate pyrrole, 5-methylthiophene, 5-chlorothiophene and 6-methoxypyridine substitution were examined. Seven of the nine synthesised compounds exhibited IC50 values <1 μM for the inhibition of MAO-B, with all compounds exhibiting higher affinities for MAO-B compared to the MAO-A isoform. The most potent MAO-B inhibitor (4h) displays an IC50 value of 0.067 μM while the most potent MAO-A inhibitor (4e) exhibits an IC50 value of 3.81 μM. It was further established that selected heterocyclic chalcones are reversible and competitive MAO inhibitors. 4h, however, may exhibit tight-binding to MAO-B, a property linked to its thiophene moiety. We conclude that high potency chalcones such as 4h represent suitable leads for the development of MAO-B inhibitors for the treatment of Parkinson's disease and possibly other neurodegenerative disorders. Copyright © 2015 Elsevier Ltd. All rights reserved.

Synthesis and evaluation of 2-benzylidene-1-tetralone derivatives for monoamine oxidase inhibitory activity.

PubMed

Amakali, Klaudia T; Legoabe, Lesetja Jan; Petzer, Anel; Petzer, Jacobus P

2018-05-01

Chalcone has been identified as a promising lead for the design of monoamine oxidase (MAO) inhibitors. This study attempted to discover potent and selective chalcone-derived MAO inhibitors by synthesising a series consisting of various cyclic chalcone derivatives. The cyclic chalcones were selected based on the possibility that their restricted structures would confer a higher degree of MAO isoform selectivity, and included the following chemical classes: 1-indanone, 1-tetralone, 1-benzosuberone, chromone, thiochromone, 4-chromanone and 4-thiochromanone. The results showed that the cyclic chalcones are in general good potency, and in most instances specific inhibitors of the human MAO-B isoform. Among these compounds, the 4-chromanone derivative was the most potent MAO-B inhibitor with an IC50 value of 0.156 µM. To further investigate the MAO inhibition of cyclic chalcones, a series of twenty-three 2-benzylidene-1-tetralone derivatives were synthesised and evaluated as MAO inhibitors. Most 2-benzylidene-1-tetralones possess good inhibitory activity and specificity for MAO-B with the most potent inhibitor displaying an IC50 value of 0.0064 µM, while the most potent MAO-A inhibitor possessed an IC50 value of 0.754 µM. This study thus shows that certain cyclic chalcones are human MAO-B inhibitors, compounds that could be suitable for the treatment of neurodegenerative disorders such as Parkinson's disease. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Effect of electronic cigarettes on human middle ear.

PubMed

Song, Jae-Jun; Go, Yoon Young; Mun, Ji Yoen; Lee, Sehee; Im, Gi Jung; Kim, Yoo Yon; Lee, Jun Ho; Chang, Jiwon

2018-06-01

Electronic cigarettes (e-cigarettes) are the most commonly used electronic nicotine delivery systems and are a relatively new product designed for smoking cessation. The market scale of electronic cigarettes is growing rapidly, but the potential impact of e-cigarettes on public health has not yet been verified. In this study, we examined the effect of e-liquids on a human middle ear epithelial cell (HMEEC) line. The main components of e-liquids are propylene glycol, vegetable glycerin and flavoring agents with or without nicotine. We analyzed 73 bottles of e-liquids from 12 different manufacturers, evaluated the trace elements in e-liquids, and identified the cytotoxicity of e-liquids on HMEECs in the presence or absence of nicotine. In the trace elements analysis, nickel, arsenic, cadmium, and lead were detected in the e-liquids. E-liquids without nicotine decreased cell viability, and the average IC 50 value of total e-liquids (n = 73) was 2.48 ± 0.93%. Among the different flavors, menthol-flavored e-liquids significantly reduced cell viability, and their average IC 50 value (n = 28) was 1.85 ± 0.80%. The average IC 50 values were distinct among manufacturers and the proportion of the solvents. The present study provides evidence that e-cigarettes influence and reduce human middle ear cell viability even without the application of nicotine. Additionally, the cytotoxicity of e-liquids was affected by the flavoring agents. Copyright © 2018 Elsevier B.V. All rights reserved.

Essential Oil Content of the Rhizome of Curcuma purpurascens Bl. (Temu Tis) and Its Antiproliferative Effect on Selected Human Carcinoma Cell Lines

PubMed Central

Hong, Sok-Lai; Lee, Guan-Serm; Ahmed Hamdi, Omer Abdalla; Awang, Khalijah; Aznam Nugroho, Nurfina

2014-01-01

Curcuma purpurascens Bl., belonging to the Zingiberaceae family, is known as temu tis in Yogyakarta, Indonesia. In this study, the hydrodistilled dried ground rhizome oil was investigated for its chemical content and antiproliferative activity against selected human carcinoma cell lines (MCF7, Ca Ski, A549, HT29, and HCT116) and a normal human lung fibroblast cell line (MRC5). Results from GC-MS and GC-FID analysis of the rhizome oil of temu tis showed turmerone as the major component, followed by germacrone, ar-turmerone, germacrene-B, and curlone. The rhizome oil of temu tis exhibited strong cytotoxicity against HT29 cells (IC50 value of 4.9 ± 0.4 μg/mL), weak cytotoxicity against A549, Ca Ski, and HCT116 cells (with IC50 values of 46.3 ± 0.7, 32.5 ± 1.1, and 35.0 ± 0.3 μg/mL, resp.), and no inhibitory effect against MCF7 cells. It exhibited mild cytotoxicity against a noncancerous human lung fibroblast cell line (MRC5), with an IC50 value of 25.2 ± 2.7 μg/mL. This is the first report on the chemical composition of this rhizome's oil and its selective antiproliferative effect on HT29. The obtained data provided a basis for further investigation of the mode of cell death. PMID:25177723

Synthesis and Evaluation of Novel Benzofuran Derivatives as Selective SIRT2 Inhibitors.

PubMed

Zhou, Yumei; Cui, Huaqing; Yu, Xiaoming; Peng, Tao; Wang, Gang; Wen, Xiaoxue; Sun, Yunbo; Liu, Shuchen; Zhang, Shouguo; Hu, Liming; Wang, Lin

2017-08-14

A series of benzofuran derivatives were designed and synthesized, and their inhibitory activites were measured against the SIRT1-3. The enzymatic assay showed that all the compounds showed certain anti-SIRT2 activity and selective over SIRT1 and SIRT3 with IC 50 (half maximal inhibitory concentration) values at the micromolar level. The preliminary structure-activity relationships were analyzed and the binding features of compound 7e (IC 50 3.81 µM) was predicted using the CDOCKER program. The results of this research could provide informative guidance for further optimizing benzofuran derivatives as potent SIRT2 inhibitors.

Synthesis of 2-acylated and sulfonated 4-hydroxycoumarins: In vitro urease inhibition and molecular docking studies.

PubMed

Rashid, Umer; Rahim, Fazal; Taha, Muhammad; Arshad, Muhammad; Ullah, Hayat; Mahmood, Tariq; Ali, Muhammad

2016-06-01

Sixteen 4-hydroxycoumarin derivatives were synthesized, characterized through EI-MS and (1)H NMR and screened for urease inhibitory potential. Three compounds exhibited better urease inhibition than the standard inhibitor thiourea (IC50=21±0.11μM) while other four compounds exhibited good to moderate inhibition with IC50 values between 29.45±1.1μM and 69.53±0.9μM. Structure activity relationship was established on the basis of molecular docking studies, which helped to predict the binding interactions of the most active compounds. Copyright © 2016 Elsevier Inc. All rights reserved.

Different susceptibility of two aquatic vertebrates (Oncorhynchus mykiss and Bufo arenarum) to azinphos methyl and carbaryl.

PubMed

Ferrari, Ana; Anguiano, Olga L; Soleño, Jimena; Venturino, Andrés; Pechen de D'Angelo, Ana M

2004-12-01

We studied the effect of two insecticides azinphos methyl and carbaryl on two resident aquatic species (Oncorhynchus mykiss and Bufo arenarum). Juvenile trout and larval stages of toad were used for exposure and recovery assays. O. mykiss was more sensitive to azinphos methyl exposure than B. arenarum larvae, with a mean 96-h LC50 of 0.007 mg/l. Carbaryl is markedly less toxic than the organophosphate and the differences in potency, expressed as LC50, for both species varies only by five-fold. The relationship between cholinesterase (ChE) inhibition and lethality is not straightforward: O. mykiss survives with an almost complete inhibition of the brain enzyme when exposed to azinphos methyl and carbaryl. Their IC50 values are one or two orders of magnitude lower than the corresponding 96-h LC50 value. In B. arenarum larvae, the IC50 values for azinphos methyl and carbaryl are one half and one third of their 96-h LC50s, respectively. The time courses of enzyme inhibition and recovery also points out differences between both types of pesticides and species. Identifying the key features conferring species selectivity can be exploited to minimize the incidence and severity of intoxication of non-target organism. The data presented here highlight the necessity of including several species and endpoint analyses in the pesticide risk evaluations of aquatic ecosystems.

Inhibition studies of soybean (Glycine max) urease with heavy metals, sodium salts of mineral acids, boric acid, and boronic acids.

PubMed

Kumar, Sandeep; Kayastha, Arvind M

2010-10-01

Various inhibitors were tested for their inhibitory effects on soybean urease. The K(i) values for boric acid, 4-bromophenylboronic acid, butylboronic acid, and phenylboronic acid were 0.20 +/- 0.05 mM, 0.22 +/- 0.04 mM, 1.50 +/- 0.10 mM, and 2.00 +/- 0.11 mM, respectively. The inhibition was competitive type with boric acid and boronic acids. Heavy metal ions including Ag(+), Hg(2+), and Cu(2+) showed strong inhibition on soybean urease, with the silver ion being a potent inhibitor (IC(50) = 2.3 x 10(-8) mM). Time-dependent inhibition studies exhibited biphasic kinetics with all heavy metal ions. Furthermore, inhibition studies with sodium salts of mineral acids (NaF, NaCl, NaNO(3), and Na(2)SO(4)) showed that only F(-) inhibited soybean urease significantly (IC(50) = 2.9 mM). Competitive type of inhibition was observed for this anion with a K(i) value of 1.30 mM.

Novel inhibitors of dengue virus methyltransferase: discovery by in vitro-driven virtual screening on a desktop computer grid.

PubMed

Podvinec, Michael; Lim, Siew Pheng; Schmidt, Tobias; Scarsi, Marco; Wen, Daying; Sonntag, Louis-Sebastian; Sanschagrin, Paul; Shenkin, Peter S; Schwede, Torsten

2010-02-25

Dengue fever is a viral disease that affects 50-100 million people annually and is one of the most important emerging infectious diseases in many areas of the world. Currently, neither specific drugs nor vaccines are available. Here, we report on the discovery of new inhibitors of the viral NS5 RNA methyltransferase, a promising flavivirus drug target. We have used a multistage molecular docking approach to screen a library of more than 5 million commercially available compounds against the two binding sites of this enzyme. In 263 compounds chosen for experimental verification, we found 10 inhibitors with IC(50) values of <100 microM, of which four exhibited IC(50) values of <10 microM in in vitro assays. The initial hit list also contained 25 nonspecific aggregators. We discuss why this likely occurred for this particular target. We also describe our attempts to use aggregation prediction to further guide the study, following this finding.

Leucettamol A: a new inhibitor of Ubc13-Uev1A interaction isolated from a marine sponge, Leucetta aff. microrhaphis.

PubMed

Tsukamoto, Sachiko; Takeuchi, Tomoharu; Rotinsulu, Henki; Mangindaan, Remy E P; van Soest, Rob W M; Ukai, Kazuyo; Kobayashi, Hisayoshi; Namikoshi, Michio; Ohta, Tomihisa; Yokosawa, Hideyoshi

2008-12-15

A compound that inhibits the formation of a complex composed of the ubiquitin E2 enzyme Ubc13 and Uev1A was isolated from the marine sponge Leucetta aff. microrhaphis. The compound was identified as leucettamol A (1) by spectroscopic analysis. Its inhibition of Ubc13-Uev1A interaction was tested by the ELISA method, revealing an IC(50) value of 50 microg/mL. The compound is the first inhibitor of Ubc13-Uev1A interaction, that is, that of the E2 activity of Ubc13. Such inhibitors are presumed to be leads for anti-cancer agents that upregulate activity of the tumor suppressor p53 protein. Interestingly, hydrogenation of 1 increased its inhibitory activity with an IC(50) value of 4 microg/mL, while its tetraacetate derivative was inactive, indicating that the hydroxy and/or amino groups of 1 are required for the inhibition.

Synthesis, characterization and anticancer studies of Ni(II), Pd(II) and Pt(II) complexes with Schiff base derived from N-methylhydrazinecarbothioamide and 2-hydroxy-5-methoxy-3-nitrobenzaldehyde

NASA Astrophysics Data System (ADS)

Arafath, Md. Azharul; Adam, Farook; Razali, Mohd. R.; Ahmed Hassan, Loiy E.; Ahamed, Mohamed B. Khadeer; Majid, Amin Malik S. A.

2017-02-01

A carbothioamide NSO tridentate Schiff base ligand (HL) and its square planar complexes Na[NiLOAc], Na[PdLOAc] and [PtLdmso] have been synthesized and characterized on the basis of melting point, elemental analysis, FT-IR, 1H NMR, 13C NMR, UV-Vis spectra. The structure of HL was elucidated with X-ray diffraction analysis. In the present study, the synthesized compounds were evaluated for their anticancer properties against three human cancer cell lines breast cancer (MCF-7), cervical (Hela), and colon (HCT-116). In addition, the cytotoxicity of the synthesized compounds was tested on a normal human cell line (human endothelial cell line EA.hy926). Among the tested compounds, the complex [NiLOAc] excelled in halting proliferation of the cervical and colon cancer cells with median inhibitory concentration (IC50) values of 28.33 and 34.4 μM, respectively. The complex, [PdLOAc] demonstrated selective cytotoxicity against breast cancer line MCF-7 with IC50 = 47.5 μM, while HL showed inhibitory effect against colon cancer cell line (HCT-116) with IC50 = 55.66 μM. The complex, [PtLdmso] showed mild activity against breast cancer (MCF-7) and cervical cancer (Hela) cells with IC50 = 64.44 and 68.3 μM, respectively, whereas, it displayed insignificant cytotoxicity against human endothelial cells (EA.hy926) with IC50 > 200 μM. Cancer cells treated with [NiLOAc] showed apoptotic features such as membrane blebbing and DNA condensation. Thus, the findings of the present study demonstrated that the series of metal complexes of HL could form the new lead for development of cancer chemotherapies to treat human cervical, breast and colon malignancies.

The monoamine oxidase inhibition properties of selected structural analogues of methylene blue.

PubMed

Delport, Anzelle; Harvey, Brian H; Petzer, Anél; Petzer, Jacobus P

2017-06-15

The thionine dye, methylene blue (MB), is a potent inhibitor of monoamine oxidase (MAO) A, a property that may, at least in part, mediate its antidepressant effects in humans and animals. The central inhibition of MAO-A by MB has also been linked to serotonin toxicity (ST) which may arise when MB is used in combination with serotonergic drugs. Structural analogues and the principal metabolite of MB, azure B, have also been reported to inhibit the MAO enzymes, with all compounds exhibiting specificity for the MAO-A isoform. To expand on the structure-activity relationships (SARs) of MAO inhibition by MB analogues, the present study investigates the human MAO inhibition properties of five MB analogues: neutral red, Nile blue, new methylene blue, cresyl violet and 1,9-dimethyl methylene blue. Similar to MB, these analogues also are specific MAO-A inhibitors with cresyl violet (IC 50 =0.0037μM), Nile blue (IC 50 =0.0077μM) and 1,9-dimethyl methylene blue (IC 50 =0.018μM) exhibiting higher potency inhibition compared to MB (IC 50 =0.07μM). Nile blue also represents a potent MAO-B inhibitor with an IC 50 value of 0.012μM. From the results it may be concluded that non-thionine MB analogues (e.g. cresyl violet and Nile blue) also may exhibit potent MAO inhibition, a property which should be considered when using these compounds in pharmacological studies. Benzophenoxazines such as cresyl violet and Nile blue are, similar to phenothiazines (e.g. MB), representative of high potency MAO-A inhibitors with a potential risk of ST. Copyright © 2017 Elsevier Inc. All rights reserved.

Utilization of Nitrophenylphosphates and Oxime-Based Ligation for the Development of Nanomolar Affinity Inhibitors of the Yersinia pestis Outer Protein H (YopH) Phosphatase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bahta, Medhanit; Lountos, George T.; Dyas, Beverly

Our current study reports the first K{sub M} optimization of a library of nitrophenylphosphate-containing substrates for generating an inhibitor lead against the Yersinia pestis outer protein phosphatase (YopH). A high activity substrate identified by this method (K{sub M} = 80 {micro}M) was converted from a substrate into an inhibitor by replacement of its phosphate group with difluoromethylphosphonic acid and by attachment of an aminooxy handle for further structural optimization by oxime ligation. A cocrystal structure of this aminooxy-containing platform in complex with YopH allowed the identification of a conserved water molecule proximal to the aminooxy group that was subsequently employedmore » for the design of furanyl-based oxime derivatives. By this process, a potent (IC{sub 50} = 190 nM) and nonpromiscuous inhibitor was developed with good YopH selectivity relative to a panel of phosphatases. The inhibitor showed significant inhibition of intracellular Y. pestis replication at a noncytotoxic concentration. The current work presents general approaches to PTP inhibitor development that may be useful beyond YopH.« less

Exploring new scaffolds for angiotensin II receptor antagonism.

PubMed

Kritsi, Eftichia; Matsoukas, Minos-Timotheos; Potamitis, Constantinos; Karageorgos, Vlasios; Detsi, Anastasia; Magafa, Vasilliki; Liapakis, George; Mavromoustakos, Thomas; Zoumpoulakis, Panagiotis

2016-09-15

Nowadays, AT1 receptor (AT1R) antagonists (ARBs) constitute the one of the most prevalent classes of antihypertensive drugs that modulate the renin-angiotensin system (RAS). Their main uses include also treatment of diabetic nephropathy (kidney damage due to diabetes) and congestive heart failure. Towards this direction, our study has been focused on the discovery of novel agents bearing different scaffolds which may evolve as a new class of AT1 receptor antagonists. To fulfill this aim, a combination of computational approaches and biological assays were implemented. Particularly, a pharmacophore model was established and served as a 3D search query to screen the ChEMBL15 database. The reliability and accuracy of virtual screening results were improved by using molecular docking studies. In total, 4 compounds with completely diverse chemical scaffolds from potential ARBs, were picked and tested for their binding affinity to AT1 receptor. Results revealed high nanomolar to micromolar affinity (IC50) for all the compounds. Especially, compound 4 exhibited a binding affinity of 199nM. Molecular dynamics simulations were utilized in an effort to provide a molecular basis of their binding to AT1R in accordance to their biological activities. Copyright © 2016 Elsevier Ltd. All rights reserved.