Investigation of the effects of thiazole compounds on thioredoxin reductase 1 (TrxR1), glutathione S-transferase (GST), and glutathione reductase (GR) targeted human brain glioblastoma cancer (U-87 MG).

Cancer is a fatal disease that kills thousands of people worldwide. Despite the information produced by research on cancer treatment, applications in cancer treatment are limited. Therefore, scientists' efforts to develop more effective treatment approaches continue. In the study, we aimed to determine the anticancer potential of amino thiazole compounds on human glioblastoma (U-87 MG) and human dermal fibroblast (HDFa) cells and their inhibition effects on enzymes that cause multidrug resistance in cancer cells. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide cell viability test was performed to understand the cytotoxic properties of thiazole derivatives. The cellular death mechanisms behind thiazole application were investigated using flow cytometry analysis. According to cell viability analysis, thiazole derivatives exhibited a greater effect on U-87 MG than the HDFa cell line in terms of cytotoxicity. Flow cytometry showed higher apoptotic cell death in U-87 MG cells than in the HDFa cell line. It can be concluded that thiazole compounds exert anticancer effects on U-87 MG and HDFa as well as show apoptotic properties. Their effects on thioredoxin reductase 1 (TrxR1), glutathione S-transferase (GST), and glutathione reductase (GR) activities, which are important in the development of chemotherapeutic methods, were also examined. From the results obtained, it was determined that the 2-amino-4-(p-tolyl)thiazole (T7) compound significantly suppressed both TrxR1 and GST activities, and the 2-amino-6-methylbenzothiazole (T8) compound significantly suppressed both TrxR1 and GST activities. Compound T7 was determined to be a selective inhibitor for TrxR1 and GST targeting, and compound T8 was determined to be a selective inhibitor for TrxR1 and GR targeting glioblastoma treatment.

Investigation of Potential Effects of Some Indole Compounds on the Glutathione S-Transferase Enzyme.

Glutathione S-transferases (GSTs) belong to the superfamily of multifunctional detoxification isoenzymes with an important role in cellular signaling. They can prevent reactive electrophilic compounds from harming the body by covalently binding identical type of moleculs to each other. GSTs can be used alone or in combination for cancer detection or diagnosis, in addition to therapeutic interventions. In recent years, indoles have become important due to their structural properties and biological activities such as antitubercular, antiulcer, anti-oxidant, and antidiabetic, as well as for the development of new anticancer agents. The current research investigated effects of some indoles with 3-carboxaldehyde structure on the GST enzyme activity. Impacts of various concentrations of indoles on the in vitro GST activity were examined. While IC50 values for the compounds ranged from 0.042 to 1.570 mM, Ki values changed between 0.018 ± 0.01 and 1.110 ± 0.15 mM. 6-Methylindole-3-carboxaldehyde (1b) exhibited the highest inhibitory effect among the indoles examined. Indole derivatives used in the study can be evaluated in further pharmacological studies due to their effects on GST activity.

Synthesis and examination of 1,2,4-triazine-sulfonamide hybrids as potential inhibitory drugs: Inhibition effects on AChE and GST enzymes in silico and in vitro conditions.

The crucial functions of acetylcholinesterase (AChE) in neurotransmission and glutathione S-transferase (GST) in detoxification and cellular protection underscore their pivotal roles as key enzymes, essential for maintaining the integrity of neurological and cellular homeostasis. For this purpose, a series of 1,2,4-triazine-sulfonamide hybrids (3a-r) was successfully synthesized, and subsequently evaluated for their inhibitory effects on AChE and GST. The investigation was complemented by molecular docking studies and ADMET (Absorption, Distribution, Metabolism, Excretion, and Toxicity) predictions. The synthesized hybrids demonstrated significant promise in inhibiting both AChE and GST activities. Molecular docking analyses provided insights into the interactions between the compounds and the target enzymes, shedding light on potential binding modes and key amino acid residues involved. Furthermore, the study benefited from ADMET predictions, offering valuable information on the compounds' pharmacokinetic properties and potential toxicity. The promising results obtained from this comprehensive approach highlight the potential of these 1,2,4-triazine-sulfonamide hybrids as effective inhibitors of AChE and GST, paving the way for further development and optimization in the pursuit of novel therapeutic agents.

LC/MS/MS Phenolic Profile, Antioxidant Capacity, Angiotensin-Converting Enzyme (ACE) and Glutathione S Transferase (GST) Inhibitory Properties of Ultrasound-Assisted Propolis Extracts.

Resinous beehive product propolis has many biological activities. It contains various aromatic substances that have great differences in their chemical composition depending on the natural flora. Thus, chemical characterization and biological properties of propolis samples is an important subject for the pharmaceutical industry. In this study, the propolis samples collected from three cities in Turkey were prepared as methanol (MEP), ethanol (EEP), chloroform (ChlEP), hexane (HxEP), and ethyl acetate (EAEP) extracts using an ultrasonic assisted technique. The antioxidant capacities of the samples were evaluated by free radical scavenging activity (DPPH), cation radical scavenging activity (ABTS), and reducing activity (CUPRAC) and (FRAP). The strongest biological activities were detected in ethanol and methanol extracts. Enzyme inhibition of the propolis samples were determined against the human glutathione S-transferase (GST) and angiotensin converting enzyme (ACE). IC50 values of MEP1, MEP2, and MEP3 samples against the ACE were found as 13.9 µg/mL, 14.8 µg/mL, and 12.8 µg/mL, while against the GST IC50 values of MEP1, MEP2, and MEP3 samples were as 5.92 µg/mL, 9.49 µg/mL, and 5.72 µg/mL. To know the possible causes of the biological test results advanced LC/MS/MS method was applied. trans-ferulic acid, kaempferol, and chrysin were found as the most abundant phenolic compounds in each sample. The propolis extracts obtained using the proper solvent have a good potential to be used in pharmaceuticals to treat the diseases related to oxidative damage, hypertension, and inflammation. Finally, the interactions between chrysin, trans-ferulic acid and kaempferol molecules with ACE and GST receptors were analyzed using molecular docking study. Selected molecules interact with active residues by binding to the active site of the receptors.

Short divalent ethacrynic amides as pro-inhibitors of glutathione S-transferase isozyme Mu and potent sensitisers of cisplatin-resistant ovarian cancers.

The linking of ethacrynic acid with ethylenediamine and 1,4-butanediamine gave EDEA and BDEA, respectively, as membrane-permeable divalent pro-inhibitors of glutathione S-transferase (GST). Their divalent glutathione conjugates showed subnanomolar inhibition and divalence-binding to GSTmu (GSTM) (PDB: 5HWL) at ∼0.35 min-1. In cisplatin-resistant SK-OV-3, COC1, SGC7901 and A549 cells, GSTM activities probed by 15 nM BDEA or EDEA revealed 5-fold and 1.0-fold increases in cisplatin-resistant SK-OV-3 and COC1 cells, respectively, in comparison with the susceptible parental cells. Being tolerable by HEK293 and LO2 cells, BDEA at 0.2 µM sensitised resistant SK-OV-3 and COC1 cells by ∼3- and ∼5-folds, respectively, released cytochrome c and increased apoptosis; EDEA at 1.0 µM sensitised resistant SK-OV-3 and A549 cells by ∼5- and ∼7-fold, respectively. EDEA at 1.7 µg/g sensitised resistant SK-OV-3 cells to cisplatin at 3.3 µg/g in nude mouse xenograft model. BDEA and EDEA are promising leads for probing cellular GSTM and sensitising cisplatin-resistant ovarian cancers.

Antitumor Effect of Organometallic Half-Sandwich Ru(II)-Arene Complexes Bearing a Glutathione S-Transferase Inhibitor.

The facile modification of the ligands in organometallic Ru(II)-arene complexes offers more opportunities to optimize their pharmacological profiles. Herein, three Ru(II)-arene complexes containing a glutathione S-transferase (GST) inhibitor (NBDHEX) in chelate ligand have been designed and synthesized in this study. In vitro results indicated that the ligation with NBDHEX significantly increased the activities and selectivities of the organometallic Ru(II)-arene complexes against tumor cells, especially complex 3, which was the most active compound among the tested compounds. DFT calculations and hydrolysis results demonstrated that complex 3 with more alkyl groups in the arene ligand has increased electron density at the Ru(II) center as compared with complexes 1 and 2, thus resulting in the improved hydrolysis rate, which may be responsible for its higher anticancer activity. Further studies showed that complexes 1-3 can cause the loss of the mitochondrial membrane potential and upregulate the expression of Bcl-2 and Bax in A549 cells, suggesting that complexes 1-3-induced cell death may be mediated via the mitochondrial apoptotic pathway. Thus, these findings suggested that simultaneous modification of the chelate ligands and arene rings in the organometallic Ru(II)-arene complexes is an effective way to improve their pharmacological properties.

Transition metal complexes of a multidentate Schiff base ligand containing pyridine: synthesis, characterization, enzyme inhibitions, antioxidant properties, and molecular docking studies.

A series of Fe(II), Ni(II), and Pd(II) complexes were prepared with a novel Schiff base ligand containing pyridine moiety. The prepared compounds were characterized using FT-IR, 1H and 13 C NMR, UV-Vis, powder XRD, thermogravimetric analysis, mass spectra, magnetic susceptibility, and elemental analysis. The coordination geometry of Fe(II) and Ni(II) complexes were octahedral, where Fe(II) and Ni(II) metal ions were coordinated by an oxygen atom of the carbonyl group, a nitrogen atom of the azomethine moiety, and a phenolic oxygen atom. The Pd(II) complex had square planar geometry. All of the synthesized compounds were tested for their biochemical properties, including enzyme inhibition and antioxidant activities. According to the in vitro DPPH and FRAP antioxidant methods, the Schiff base ligand and its Fe(II)/Pd(II) complexes showed close antioxidant activities against the standards (BHA, BHT, ascorbic acid, and α-tocopherol). Enzyme inhibitions of the metal complexes were investigated against glutathione S-transferase (GST), acetylcholinesterase (AChE), and butyrylcholinesterase (BChE) enzymes. The best inhibition value (Ki) was observed for the Ni(II) complex against GST (2.63 ± 0.04 µM). Also, the Pd(II) complex showed the best inhibition value (10.17 ± 1.88 µM) against AChE. Molecular docking specified significant interactions at the active pockets of respective target enzymes. The Ni(II) complex exhibited good binding affinity against both BChE (- 9.0 kcal/mol and 9.36 ± 2.03 µM) and GST (- 7.0 kcal/mol and 2.63 ± 0.04 µM) enzymes.

Synthesis of novel 1,2,3 triazole derivatives and assessment of their potential cholinesterases, glutathione S-transferase enzymes inhibitory properties: An in vitro and in silico study.

In this study, new 1,2,3-triazole derivatives containing chalcone core (1-7) were synthesized. Obtained compounds were characterized by IR, 1H NMR, 13C NMR, and mass studies. Characterized compounds (1-7) inhibitory effects were tested against the glutathione S-transferase (GST), acetylcholinesterase (AChE), and Butyrylcholinesterase (BChE). Their Ki values were in the range of 5.88-11.13 µM on AChE, 5.08-15.12 µM on BChE, and 9.82-13.22 µM on GST. Remarkable inhibitory effects were obtained against three tested metabolic enzymes. Also, binding scores of the best-inhibitors against AChE, BChE, and GST enzymes were detected as -9.969 kcal/mol, -10.672 kcal/mol, and -8.832 kcal/mol, respectively. Isoindoline-1,3-dione and benzothiophene moieties played a critical role in the inhibition of AChE and BChE enzymes, respectively. Phenylene and triazole moieties had the most important interactions for inhibition of the GST enzyme. Therefore, in vivo and in silico results indicated that these compounds can be considered in drug design processes for the treatment of some diseases including Alzheimer's disease (AD), leukemia, and some type of cancer.

Synthesis, design, and assessment of novel morpholine-derived Mannich bases as multifunctional agents for the potential enzyme inhibitory properties including docking study.

The synthesized Schiff Bases were reacted with formaldehyde and secondary amine such as 2,6-dimethylmorpholine to afford N-Mannich bases through the Mannich reaction. 3-Substitued-4-(4-hydroxybenzylidenamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones (4) were treated with 2,6-dimethylmorpholine in the presence of formaldehyde to synthesize eight new 1-(2,6-dimethylmorpholino-4-yl-methyl)-3-substitued-4-(4-hydroxybenzylidenamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones (4a-h). The structures of the synthesized eight new compounds were characterized using IR, 1H NMR, 13C NMR, and HR-MS spectroscopic methods. Synthesized compounds inhibitory activity determined against the acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and glutathione S-transferase (GST) enzymes with Ki values in the range 25.23-42.19 µM for AChE, 19.37-34.22 µM for BChE, and 21.84-41.14 µM for GST, respectively. Binding scores of most active inhibitors against AChE, BChE, and GST enzymes were detected as -10.294 kcal/mol, -9.562 kcal/mol, and -7.112 kcal/mol, respectively. The hydroxybenzylidene moiety of the most active inhibitors caused to inhibition of the enzymes through hydrophobic interaction and hydrogen bond.

Larvicidal and ovicidal activities of phenyl acetic acid isolated from Streptomyces collinus against Culex quinquefasciatus Say and Aedes aegypti L. (Diptera: Culicidae).

The bio-efficacy of crude ethyl acetate extract, fractions and a compound phenyl acetic acid from the ethyl acetate extract of Streptomyces collinus was evaluated on Culex quinquefasciatus Say and Aedes aegypti L. mosquitoes (Diptera: Culicidae). The larvae were exposed to concentrations of 2.5, 5.0, 7.5 and 10.0 ppm for fractions and 0.5, 1.0, 1.5 and 2.0 ppm for compound. After 24 h, the larval mortality was assessed and the LC50 and LC90 values were calculated. Similarly, per cent ovicidal activity was calculated for eggs after 120 h post treatment for phenyl acetic acid. Among the eleven fractions screened, fraction 7 from the ethyl acetate extract of Streptomyces collinus exhibited good larvicidal activity against both mosquito species. The LC50 and LC90 values of fraction 7 were 4.42, 6.23 ppm against Cx. quinquefasciatus larvae and 5.13, 14.51 ppm against Ae. aegypti larvae, respectively. Further, the isolated compound, phenyl acetic acid from fraction 7 recorded 100% larvicidal activity at 2 ppm concentration with LC50 and LC90 values of 2.07, 4.87 ppm on Cx. quinquefasciatus larvae and 3.81, 9.87 ppm on Ae. aegypti larvae, respectively. Phenyl acetic acid presented 50.3% and 42.0% ovicidal activity against Cx. quinquefasciatus and Ae. aegypti eggs at 2 ppm concentration after 120 h post treatment. The compound, phenyl acetic acid could be used in mosquito control programme.

Synthesis, Spectroscopic Analysis, and in Vitro/in Silico Biological Studies of Novel Piperidine Derivatives Heterocyclic Schiff-Mannich Base Compounds.

In the present study, 3-substitued-4-(4-hydroxybenzylidenamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones (S1-8) were synthesized by treating 4-hydroxybenzaldehyde (B) with eight different 3-substitued-4-amino-4,5-dihydro-1H-1,2,4-triazole-5-ones (T1-8) in acetic acid medium, separately. The synthesized Schiff bases (S) were reacted with formaldehyde and secondary amine such as 4-piperidinecarboxyamide to afford novel heterocyclic bases. 3-Substitued-4-(4-hydroxybenzylidenamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones (T) were treated with 4-piperidinecarboxyamide in the presence of formaldehyde to synthesize eight new 1-(4-piperidinecarboxyamide-1-yl-methyl)-3-substitued-4-(4-hydroxybenzylidenamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones (M1-8). The structure characterization of compounds was carried out using 1 H-NMR, IR, HR-MS, and 13 C-NMR spectroscopic methods. The inhibitory properties of the newly synthesized compounds were calculated against the acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and glutathione S-transferase (GST) enzymes. Ki values were calculated in the range of 20.06±3.11-36.86±6.17 µM for GST, 17.87±2.91-30.53±4.25 µM for AChE, 9.08±0.69-20.02±2.88 µM for BChE, respectively, Besides, IC50 values were also calculated. Best binding scores of -inhibitors against used enzymes were calculated as -12.095 kcal/mol, -12.775 kcal/mol, and -9.336 kcal/mol, respectively. While 5-oxo-triazole piperidine-4-carboxamide moieties have a critical role in the inhibition of AChE and GST enzymes, hydroxy benzyl moiety is important for BChE enzyme inhibition.

The Interaction of Human Glutathione Transferase GSTA1-1 with Reactive Dyes.

Human glutathione transferase A1-1 (hGSTA1-1) contributes to developing resistance to anticancer drugs and, therefore, is promising in terms of drug-design targets for coping with this phenomenon. In the present study, the interaction of anthraquinone and diazo dichlorotriazine dyes (DCTD) with hGSTA1-1 was investigated. The anthraquinone dye Procion blue MX-R (PBMX-R) appeared to interact with higher affinity and was selected for further study. The enzyme was specifically and irreversibly inactivated by PBMX-R, following a biphasic pseudo-first-order saturation kinetics, with approximately 1 mol of inhibitor per mol of the dimeric enzyme being incorporated. Molecular modeling and protein chemistry data suggested that the modified residue is the Cys112, which is located at the entrance of the solvent channel at the subunits interface. The results suggest that negative cooperativity exists upon PBMX-R binding, indicating a structural communication between the two subunits. Kinetic inhibition analysis showed that the dye is a competitive inhibitor towards glutathione (GSH) and mixed-type inhibitor towards 1-chloro-2,4-dinitrobenzene (CDNB). The present study results suggest that PBMX-R is a useful probe suitable for assessing by kinetic means the drugability of the enzyme in future drug-design efforts.

Pharmacokinetic and Biochemical Profiling of Sodium Dichloroacetate in Pregnant Ewes and Fetuses.

Sodium dichloroacetate (DCA) is an investigational drug that shows promise in the treatment of acquired and congenital mitochondrial diseases, including myocardial ischemia and failure. DCA increases glucose utilization and decreases lactate production, so it may also have clinical utility in reducing lactic acidosis during labor. In the current study, we tested the ability of DCA to cross the placenta and be measured in fetal blood after intravenous administration to pregnant ewes during late gestation and labor. Sustained administration of DCA to the mother over 72 hours achieved pharmacologically active levels of DCA in the fetus and decreased fetal plasma lactate concentrations. Multicompartmental pharmacokinetics modeling indicated that drug metabolism in the fetal and maternal compartments is best described by the DCA inhibiting lactate production in both compartments, consistent with our finding that the hepatic expression of the DCA-metabolizing enzyme glutathione transferase zeta1 was decreased in the ewes and their fetuses exposed to the drug. We provide the first evidence that DCA can cross the placental compartment to enter the fetal circulation and inhibit its own hepatic metabolism in the fetus, leading to increased DCA concentrations and decreased fetal plasma lactate concentrations during its parenteral administration to the mother. SIGNIFICANCE STATEMENT: This study was the first to administer sodium dichloroacetate (DCA) to pregnant animals (sheep). It showed that DCA administered to the mother can cross the placental barrier and achieve concentrations in fetus sufficient to decrease fetal lactate concentrations. Consistent with findings reported in other species, DCA-mediated inhibition of glutathione transferase zeta1 was also observed in ewes, resulting in reduced metabolism of DCA after prolonged administration.

Effects of Multiple Doses of Dichloroacetate on GSTZ1 Expression and Activity in Liver and Extrahepatic Tissues of Young and Adult Rats.

Glutathione transferase zeta 1 (GSTZ1), expressed in liver and several extrahepatic tissues, catalyzes dechlorination of dichloroacetate (DCA) to glyoxylate. DCA inactivates GSTZ1, leading to autoinhibition of its metabolism. DCA is an investigational drug for treating several congenital and acquired disorders of mitochondrial energy metabolism, including cancer. The main adverse effect of DCA, reversible peripheral neuropathy, is more common in adults treated long-term than in children, who metabolize DCA more quickly after multiple doses. One dose of DCA to Sprague Dawley rats reduced GSTZ1 expression and activity more in liver than in extrahepatic tissues; however, the effects of multiple doses of DCA that mimic its therapeutic use have not been studied. Here, we examined the expression and activity of GSTZ1 in cytosol and mitochondria of liver, kidney, heart, and brain 24 hours after completion of 8-day oral dosing of 100 mg/kg per day sodium DCA to juvenile and adult Sprague Dawley rats. Activity was measured with DCA and with 1,2-epoxy-3-(4-nitrophenoxy)propane (EPNPP), reported to be a GSTZ1-selective substrate. In DCA-treated rats, liver retained higher expression and activity of GSTZ1 with DCA than other tissues, irrespective of rodent age. DCA-treated juvenile rats retained more GSTZ1 activity with DCA than adults. Consistent with this finding, there was less measurable DCA in tissues of juvenile than adult rats. DCA-treated rats retained activity with EPNPP, despite losing over 98% of GSTZ1 protein. These data provide insight into the differences between children and adults in DCA elimination under a therapeutic regimen and confirm that the liver contributes more to DCA metabolism than other tissues. SIGNIFICANCE STATEMENT: Dichloroacetate (DCA) is one of few drugs exhibiting higher clearance from children than adults, after repeated doses, for reasons that are unclear. We hypothesized that juveniles retain more glutathione transferase zeta 1 (GSTZ1) than adults in tissues after multiple DCA doses and found this was the case for liver and kidney, with rat as a model to assess GSTZ1 protein expression and activity with DCA. Although 1,2-epoxy-3-(4-nitrophenoxy)propane was reported to be a selective GSTZ1 substrate, its activity was not reduced in concert with GSTZ1 protein.

Exposure of Rats to Multiple Oral Doses of Dichloroacetate Results in Upregulation of Hepatic Glutathione Transferases and NAD(P)H Dehydrogenase [Quinone] 1.

Dichloroacetate (DCA) is an investigational drug that is used in the treatment of various congenital and acquired disorders of energy metabolism. Although DCA is generally well tolerated, some patients experience peripheral neuropathy, a side effect more common in adults than children. Repetitive DCA dosing causes downregulation of its metabolizing enzyme, glutathione transferase zeta 1 (GSTZ1), which is also critical in the detoxification of maleylacetoacetate and maleylacetone. GSTZ1 (-/-) knockout mice show upregulation of glutathione transferases (GSTs) and antioxidant enzymes as well as an increase in the ratio of oxidized glutathione (GSSG) to reduced glutathione (GSH), suggesting GSTZ1 deficiency causes oxidative stress. We hypothesized that DCA-mediated depletion of GSTZ1 causes oxidative stress and used the rat to examine induction of GSTs and antioxidant enzymes after repeated DCA exposure. We determined the expression of alpha, mu, pi, and omega class GSTs, NAD(P)H dehydrogenase [quinone] 1 (NQO1), gamma-glutamylcysteine ligase complex (GCLC), and glutathione synthetase (GSS). GSH and GSSG levels were measured by liquid chromatography-tandem mass spectrometry. Enzyme activity was measured in hepatic cytosol using 1-chloro-2,4-dinitrobenzene, 1,2-dichloro-4-nitrobenzene, and 2,6-dichloroindophenol as substrates. In comparison with acetate-treated controls, DCA dosing increased the relative expression of GSTA1/A2 irrespective of rodent age, whereas only adults displayed higher levels of GSTM1 and GSTO1. NQO1 expression and activity were higher in juveniles after DCA dosing. GSH concentrations were increased by DCA in adults, but the GSH:GSSG ratio was not changed. Levels of GCLC and GSS were higher and lower, respectively, in adults treated with DCA. We conclude that DCA-mediated depletion of GSTZ1 causes oxidative stress and promotes the induction of antioxidant enzymes that may vary between age groups. SIGNIFICANCE STATEMENT: Treatment with the investigational drug, dichloroacetate (DCA), results in loss of glutathione transferase zeta 1 (GSTZ1) and subsequent increases in body burden of the electrophilic tyrosine metabolites, maleylacetoacetate and maleylacetone. Loss of GSTZ1 in genetically modified mice is associated with induction of glutathione transferases and alteration of the ratio of oxidized to reduced glutathione. Therefore, we determined whether pharmacological depletion of GSTZ1 through repeat administration of DCA produced similar changes in the liver, which could affect responses to other drugs and toxicants.

Generation of oxidative stress and induction of apoptotic like events in curcumin and thymoquinone treated adult Fasciola gigantica worms.

Fasciolosis is a neglected tropical disease caused by the liver fluke Fasciola gigantica. The absence of successful vaccine and emerging resistance in flukes against the drug of choice, triclabendazole, has necessitated the search for alternatives including phyto-therapeutic approaches. Curcumin and thymoquinone, the active ingredients of Curcuma longa and Nigella sativa plants respectively, were first screened for their binding affinity with Glutathione-S-transferase (GST) molecule through in silico molecular docking followed by in vitro treatment of worms with varying concentrations of the test compounds. The in silico molecular docking of curcumin and thymoquinone with sigma GST revealed strong hydrogen bonding as well as hydrophobic interactions with high fitness scores but showing inter-specific differences. The in vitro treatment of F. gigantica worms with both curcumin and thymoquinone resulted in a significant increase in the generation of reactive oxygen species (ROS) whereas the level of reduced glutathione, a primary redox regulator, was found to be significantly decreased (p < 0.05). The two compounds not only inhibited the GST activity, which is an important detoxification enzyme and also a key drug/vaccine target for the control of fasciolosis but also significantly inhibited the activity of antioxidant enzymes glutathione peroxidase and glutathione reductase that are vital in maintenance of redox homeostasis. The immunohistochemistry performed using anti sigma GST polyclonal antibodies revealed that both the compounds used in the present study significantly reduced immunofluorescence in the vitellaria, developing eggs present in the ovary and the intestinal caecae indicating inhibition of GST enzyme in these regions of the worms. Further, following treatment with curcumin and thymoquinone, chromatin condensation and DNA fragmentation was also observed in F. gigantica worms. In conclusion, both curcumin and thymoquinone generated oxidative stress in the worms by production of ROS and significantly inhibiting their antioxidant and detoxification ability. The oxidative stress along with induction of apoptotic like events would compromise the survival ability of worms within the host. However, further studies are required to establish their anthelmintic potential alone and in combination with the commonly used anthelmintic drugs under in vivo conditions.

Novel benzo[b]xanthene derivatives: Bismuth(III) triflate-catalyzed one-pot synthesis, characterization, and acetylcholinesterase, glutathione S-transferase, and butyrylcholinesterase inhibitory properties.

In this study, 3,4-dihydro-12-aryl-1H-benzo[b]xanthene-1,6,11-(2H,12H)trione compounds were obtained through one-pot condensation of various substituted aromatic aldehydes, 2-hydroxy-1,4-naphthoquinone, and dimedone in the presence of Bi(OTf)3 as a green and reusable catalyst. The structural characterization of these novel substituted benzo[b]xanthenes was performed by spectroscopic methods, and their inhibitory actions against butyrylcholinesterase (BChE), acetylcholinesterase (AChE), and glutathione S-transferase (GST) were investigated. GST is an enzyme responsible for removing toxic molecules during Phase II reactions in the detoxification mechanism. The AChE and BChE enzymes, which are called cholinesterases, are among the enzymes that occur especially during dementia such as brain damage or Alzheimer's disease. Inhibition effects of the benzo[b]xanthene derivatives on AChE, BChE, and GST were found at the millimolar level. The best inhibitor for GST is compound 4a (31.18 ± 6.13 mM), for AChE, it is compound 4d (28.16 ± 3.46 mM), and for BChE, it is compound 4f (36.24 ± 3.19 mM). Compound 4a inhibited the dimerization of GST subunits, and compounds 4d and 4f directly inhibited the catalytic activity by interacting with the catalytic active site or a related site of the AChE and BChE enzymes, respectively.

The synthesis of one H-2 labeled and two H-3 labeled leukotriene C4 synthase inhibitors.

As part of a medicinal chemistry program aimed at developing a leukotriene C4 synthase inhibitor for the treatment of asthma, two tritium-labeled and one stable isotope-labeled compounds were required. The synthesis of the tritium-labeled compounds used a standard bromination-tritiodehalogentation approach. One of the tritium-labeled compounds was observed to exchange its tritium label slowly with the solvent. The stable isotope-labeled compound was prepared in seven steps (3% overall yield) from [2 H6 ]acetone in a modification of the route used by medicinal chemistry.

Evaluation of Glutathione S-Transferase Inhibition Effects on Idiopathic Pulmonary Fibrosis Therapy with a Near-Infrared Fluorescent Probe in Cell and Mice Models.

Idiopathic pulmonary fibrosis (IPF) is a lung-limited and progressive fibrotic disease. The early diagnosis and therapies of IPF are still full of clinical challenges. Glutathione S-transferase (GSTs) plays significant roles in promoting the formation of pulmonary fibrosis. Herein, we report a fluorescent probe (Cy-GST) for the detection of GSTs concentration fluctuations in cells and in mice models. The probe can selectively and sensitively respond to GSTs with an "off-on" type fluorescence switch. Our results demonstrated that the level of intracellular GSTs increase in the pulmonary fibrosis cells and mice models. And the IPF patients hold high levels of GSTs concentrations. Thus, GSTs are likely to play important roles in pulmonary fibrosis. The inhibitor of GSTs TLK117 can reduce the severity of pulmonary fibrosis. The synergistic treatment of TLK117 and pirfenidone have better therapeutic effects than only using pirfenidone in pulmonary fibrosis mice models. The level of GSTs in IPF may be a new potential marker for IPF diagnosis. And the inhibition of GSTs may be a new therapeutic strategy for IPF treatment.

Mitochondrial Glutathione Transferase Zeta 1 Is Inactivated More Rapidly by Dichloroacetate than the Cytosolic Enzyme in Adult and Juvenile Rat Liver.

Dichloroacetate (DCA) has potential for treating mitochondrial disorders and cancer by activating the mitochondrial pyruvate dehydrogenase complex. Repeated dosing of DCA results in reduced drug clearance due to inactivation of glutathione transferase ζ1 (GSTZ1), its metabolizing enzyme. We investigated the time-course of inactivation of GSTZ1 in hepatic cytosol and mitochondria after one oral dose of 100 mg/kg DCA to female Sprague-Dawley rats aged 4 weeks (young) and 52 weeks (adult) as models for children and adults, respectively. GSTZ1 activity with both DCA and an endogenous substrate, maleylacetone (MA), as well as GSTZ1 protein expression were rapidly reduced in cytosol from both ages following DCA treatment. In mitochondria, loss of GSTZ1 protein and activity with DCA were even more rapid. The cytosolic in vivo half-lives of the loss of GSTZ1 activity with DCA were 1.05 ± 0.03 and 0.82 ± 0.02 h (mean ± S.D., n = 6) for young and adult rats, respectively, with inactivation significantly more rapid in adult rats, p < 0.001. The mitochondrial inactivation half-lives were similar in young (0.57 ± 0.02 h) and adult rats (0.54 ± 0.02 h) and were significantly (p < 0.0001) shorter than cytosolic inactivation half-lives. By 24 h after DCA administration, activity and expression remained at 10% or less than control values. The in vitro GSTZ1 inactivation half-lives following incubation with 2 mM DCA in the presence of physiological chloride (Cl-) concentrations (cytosol = 44 mM, mitochondria = 1-2 mM) exhibited marked differences between subcellular fractions, being 3 times longer in the cytosol than in the mitochondria, regardless of age, suggesting that the lower Cl- concentration in mitochondria explained the faster degradation of GSTZ1. These results demonstrate for the first time that rat mitochondrial GSTZ1 is more readily inactivated by DCA than cytosolic GSTZ1, and cytosolic GSTZ1 is inactivated more rapidly in adult than young rats.