Celastrol ameliorates acetaminophen-induced oxidative stress and cytotoxicity in HepG2 cells.

Acetaminophen (APAP) is the most commonly used analgesic and antipyretic drug in the world. However, hepatotoxicity caused by APAP overdose is the most frequent cause of acute liver failure worldwide and oxidative stress involved in the pathogenesis of APAP hepatotoxicity. Celastrol is a natural triterpenoid derived from Tripterygium wilfordii Hook F. that exhibits antioxidant, anti-inflammatory, and antitumor activities. In this study, we aimed to investigate the potential ameliorative effects of celastrol against APAP-induced cytotoxicity and oxidative stress. Human hepatocellular carcinoma cells (HepG2) were incubated with 20 mM of APAP for 24 h and posttreated with 50 nM, 100 nM, or 200 nM of celastrol for a further 24 h. The methylthiazolyldiphenyl-tetrazolium bromide, lactate dehydrogenase, and neutral red uptake assays showed celastrol posttreatments recovered cell viability and cell membrane integrity in a concentration-dependent manner. Celastrol posttreatments exerted a significant increase in the glutathione content and a decrease in the malondialdehyde and protein carbonylation levels. Also, celastrol posttreatments attenuated the APAP-induced oxidative stress by raising glutathione peroxidase, glutathione reductase, and catalase activities. However, superoxide dismutase activity did not change. In conclusion, celastrol treatment may improve cell viability and increase cellular antioxidant defense in HepG2 cells. These results suggest that celastrol may have the potential to ameliorate the APAP-induced oxidative stress and cytotoxicity.

Investigation on the toxic potential of Tribulus terrestris in vitro.

CONTEXT: Tribulus terrestris L. (Zygophyllaceae) has been commonly used to energize, vitalize, and improve sexual function and physical performance in men. OBJECTIVE: This study investigates the potential cytotoxic and genotoxic, and endocrine disrupting activities of T. terrestris in vitro. MATERIALS AND METHODS: The whole T. terrestris plant was extracted with water, methanol, and chloroform. The genotoxic potential of T. terrestris extracts at 3-2400 µg/mL was assessed by Comet assay in a rat kidney cell line (NRK-52E) and by Ames assay in Salmonella typhimurium TA98 and TA100 strains. Endocrine disrupting effects of the extracts at concentrations of 0.22-25 000 µg/mL were assessed by YES/YAS assay in Saccharomyces cerevisiae. Cytotoxic activity of the extracts was determined by the MTT test in NRK-52E cells. The different exposure times were used for four tests (3-48 h). RESULTS: The methanol extract of T. terrestris IC50 value was 160 µg/mL. The other extracts did not show cytotoxic effects. In the Comet and Ames genotoxicity assays, none of the extracts possessed genotoxic activities at concentrations of 0-2400 µg/mL. Only the water extract of T. terrestris induced frame shift mutations after metabolic activation. The water extract also showed estrogenic activity by YES/YAS assay in S. cerevisiae at concentrations ≥27 µg/mL (≥2.6-fold), while the other T. terrestris extracts had anti-estrogenic properties. CONCLUSION: Tribulus terrestris had estrogenic and genotoxic activities. The study was useful in determining its toxicological effects and the precautions regarding consumption.

Effects of bentazone on lipid peroxidation and antioxidant systems in human erythrocytes in vitro.

Bentazone, a benzothiadiazole herbicide, is widely used for a variety of crops including cereals, maize, peas, rice and soy beans. The concern for human health is stil very high because bentazone is continuously monitored in environment and several studies to evaluate its potential carcinogenic effects when chronic and high doses were administered to animals. We aimed to investigate the possible effects of bentazone on lipid peroxidation, levels of glutathione and activities of antioxidant enzymes in human erythrocytes in vitro. For that, erythrocyte were incubated with bentazone in different concentrations (0-50 nM) at 37 °C for 1 hr. Bentazone showed significant increase in the levels of malondialdehyde (MDA) at the highest concentration in erythrocytes as an index of lipid peroxidation. Besides, alterations in the levels of reduced glutathione (GSH) and activities of glutathione peroxidase (GSH-Px) were observed while the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione reductase (GSH-Rd) were unchanged. In conclusion, findings from this study indicate that in vitro toxicity of bentazone may be associated with oxidative stress and this work warrants further in vivo investigations.

Acute pancreatitis is associated with Ser608Leu iNOS polymorphism.

Acute pancreatitis is an initially localized inflammation of the pancreatic gland. The precise mechanisms by which aetiological factors induce acute pancreatitis are not yet known, but when initiated, common inflammatory pathways seem to be involved, with cytokines being their components of major importance. The inducible nitric oxide synthase gene (iNOS) encodes an enzyme involved in the pathway of reactive oxygen species and induced in response to infection, cytokines. iNOS is capable of generating large quantities of nitric oxide produced during inflammation. The objective of this study was to investigate the association between acute pancreatitis risk and iNOS polymorphisms. The studied single-nucleotide polymorphisms (SNPs) were Ser608Leu, resulting in an amino acid substitution, and 1173C/T and 954G/C, both in the gene promoter region that is linked to increased enzyme expression, leading to higher NO production. The genotypes for the three SNPs were determined in 93 patients with acute pancreatitis and 60 controls without pancreatitis or cancer that were matched for age and gender. Data analysis was done by conditional logistic regression. It was found that the Ser608Leu polymorphism was more frequent among cases with acute pancreatitis compared to controls (OR = 2.88; 95% CI: 1.49-5.57; P = 0.002), although no individually statistically significant associations for the other SNPs studied were detected. We suggest that iNOS Ser608Leu can be used as a marker to define the risk of acute pancreatitis.

Determination of some beta-blockers as dabsyl derivatives by HPLC.

A HPLC method has been developed that permits the sensitive determination of beta adrenergic blocking drugs, including acebutolol, metoprolol, oxprenolol, pindolol, and propranolol. These compounds were converted to their chromophoric dabsyl derivatives and were separated by a reversed phase chromatographic column (mu-Bondapak C18) with methanol-water (75:25) as isocratic mobile phase. The derivatives were detected by a variable wavelength detector operating at 430 nm. The method was applied to commercial pharmaceutical preparations and the results were statistically compared with those obtained by official methods using t- and F-tests.