Inhibition of glutathione generation in hepatic steatotic rats augments oxidative stress

Fatty liver disease has been strongly associated with a low glutathione (GSH) level in hepatocytes with increased oxidative stress, which is critically involved in the initiation and progression of the disease. The study investigated whether the GSH deficiency induced by buthionine sulfoximine (BSO), an inhibitor of γ-glutamyl cysteine synthetase, can be restored by the administration of GSH ester. We showed that mice fed a diet with cholesterol plus sodium cholate developed steatosis followed by hepatic GSH reduction. Moreover, the GSH level in the cytosol and mitochondria of steatosis plus BSO decreased than that of steatosis alone. Subsequent studies with the liver tissues and plasma of BSO plus steatosis revealed the accumulation of cholesterol in the hepatocytes, downregulating the concentration of GSH, antioxidant enzymes, and GSH metabolizing enzymes with a significant rise in reactive oxygen species (ROS), blood glucose level and plasma lipid profile. The administration of GSH ester in BSO-administered mice, prevented the depletion of GSH by upregulating the GSH concentration, antioxidant enzymes, and GSH metabolizing enzymes, followed by a reduction in ROS and plasma lipid concentration. The histopathological analysis showed a marked increase in inflammation followed by hepatocytes ballooning in BSO-induced group and steatosis control group, which was ameliorated by GSH ester administration. In conclusion, our data suggest that the restoration of GSH in the cytosol and mitochondria through the injection with GSH ester plays a principal role in maintaining the GSH level in the liver, thereby delaying the progression of fatty liver disease.

Brassica nigra plays a remedy role in hepatic and renal damage

CONTEXT

Black mustard [Brassica nigra (L.) Koch] of the Brassicaceae (Cruciferae) family is commonly used as a spice and a cheap source of antimicrobial agents for bacterial infections.

OBJECTIVES

The present investigation was to demonstrate the protective effect of the methanol extract of B. nigra leaves against D-galactosamine (D-GalN)-induced hepatic and nephrotoxicity in Wistar rats.

METHODS

Activity of the methanol extract of B. nigra at doses of 200 and 400 mg/kg b.wt. against D-GalN (500 mg/kg b.wt.) induced toxicity, with silymarin used as the standard. Histological damage, activities of serum marker enzyme, hematological changes, metabolites such as bilirubin, urea, uric acid, and creatinine levels, tissue thiobarbutric acid reactive substance, enzymic and non-enzymic antioxidants and inflammatory marker enzymes such as myeloperoxidase, cathepsin D, and acid phosphatase were assessed.

RESULTS

The D-GalN-induced toxicity was evident from a significant increase (p < 0.001) in the serum and tissue inflammatory markers in toxic rats, when compared with the control (saline alone treated animals). The B. nigra pretreated groups (200 and 400 mg/kg b.wt.) showed significant (p < 0.001) reduction in the D-GalN-induced toxicity as obvious from biochemical parameters. Histopathological observations confirm the protective effect of B. nigra leaf extract by reduction in hepatic and renal tissue damage. Experimentals extract showed a similar effect as the standard.

CONCLUSIONS

The crude methanol extract of B. nigra leaf lacks inherent toxicity and exhibits hepatic and nephroprotective effects against D-GalN-induced toxicity in Wistar rats.

Identification, quantification of bioactive constituents, evaluation of antioxidant and in vivo acute toxicity property from the methanol extract of Vernonia cinerea leaf extract

CONTEXT

Vernonia cinerea (L.) Less [Compositae (Asteraceae)] is used traditionally for several medical purposes such as inflammation, pain, fever, and cancer.

OBJECTIVES

The present study identified the bioactive constituents in the methanol extract of Vernonia cinerea leaf and evaluated its antioxidant activity and acute toxicity.

METHODS

The identification of phytochemicals was accomplished by GC-MS and the major antioxidant phenolic compounds in the extract were quantified by HPTLC analysis. To quantify the essential elements, atomic absorption spectrophotometeric analysis was carried out. Total phenol and flavonoid content was measured by Folin-Ciocalteau reagent and 2% aluminium chloride, respectively.

RESULTS

GC-MS analysis identified the presence of 27 phytoconstituents. The predominant phenolic compound in the extract as quantified by HPTLC was gallic acid (1.92 mg/g) followed by rutin (0.705 mg/g), quercetin (0.173 mg/g), caffeic acid (0.082 mg/g) and ferulic acid (0.033 mg/g). The following elements were quantified: Fe (0.050 ppm), Mn (0.022 ppm), Co (0.0180 ppm), Pb (0.029 ppm), Hg (3.885 ppm) and Se (4.5240 ppm). The antioxidant activity of the extract increased with increasing concentration and the correlation (r²) for all in vitro assays were satisfactory.

CONCLUSIONS

V. cinerea extract has significant (p < 0.05) antiradical activity. Hence, V. cinerea may have potential medicinal value and can be used in the formulation of pharmacological products for degenerative diseases.