Protective effects of Cholestin on ethanol induced oxidative stress in rats.

BACKGROUND: Male Wistar rats were divided into seven groups as follows: group A, basal diet; group B, basal diet with Cholestin at 0.1667 g kg⁻¹ body weight (BW); groups C-F, oral feeding of ethanol at 7.9 g kg⁻¹ BW; groups D-F, Cholestin in diet at 0.1667, 0.3333 and 0.5 g kg⁻¹ BW respectively; group G, silymarin in diet at 200 mg kg⁻¹ BW. RESULTS: The results showed that treatment with Cholestin for 8 weeks reduced the impact of ethanol toxicity on serum markers of liver damage: aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP). The antioxidant system was significantly enhanced: plasma and hepatic thiobarbituric acid-reactive substance (TBARS) levels were lowered while hepatic superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), ethanol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) activities and non-enzymatic antioxidants (vitamin E, vitamin C and GSH) were elevated. CONCLUSION: Cholestin shows a protective effect against hepatotoxicity indices in ethanol-fed rats comparable to that of silymarin, as supported by the evaluation of liver histopathology. The data suggest that Cholestin exerts its hepatoprotective effect by decreasing lipid peroxidation and improving antioxidants status, thus proving itself as an effective antioxidant in ethanol-induced oxidative damage in rats.

Ameliorative effect of Pracparatum mungo extract on high cholesterol diets in hamsters.

This study was designed to test the lipid-lowering and antioxidative activities of Pracparatum mungo extract (PME), in comparison to its components berberine and glycyrrhizin in cholesterol-fed hamsters. The PME and berberine significantly lowered the atherogenic index compared to glycyrrhizin and the control (P < 0.05). The hepatic HMG-CoA reductase activity was significantly lower in the PME and berberine groups than in the glycyrrhizin group (P < 0.05), while the hepatic ACAT activity was significantly decreased by all treatments with respect to the high cholesterol fed group (P < 0.05). The overall potential of the antioxidant system was significantly enhanced by the PME, berberine and glycyrrhizin supplements as the plasma and hepatic TBARS levels were lowered while the hepatic superoxide dismutase activity and glutathione levels, HMG-CoA reductase, LDL receptor, PPAR, SREBP-2 and CYP7A1 mRNA expressions were increased by the treatments of PME and berberine in comparison with the high cholesterol fed hamsters (P < 0.05). Collectively, these results suggest that the supplementation of PME, berberine and glycyrrhizin increased antioxidant activity in hamsters. Furthermore, we observed that PME and berberine groups promoted the excretion of neutral and acidic sterols (P < 0.05), that could contribute to explain the lower plasma and hepatic cholesterol levels found in the treated animals.

Effects of yam peel extract against carbon tetrachloride-induced hepatotoxicity in rats.

The phenolic acid and flavonoid profiles in yam peel extract were determined by HPLC. Quercetin, hesperidin, and apigenin were predominant components in yam peel extract. Male Wistar rats were orally treated with yam peel extract (100.02, 266.72, and 433.42 mg/kg) or silymarin (200 mg/kg) daily, with administration of CCl4 (1 mL/kg, 20% CCl4 in olive oil) twice a week. Yam peel extract for 8 weeks significantly reduced the impact of CCl4 toxicity on the serum markers of liver damage, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP). The overall potential of the antioxidant system was significantly enhanced by the yam peel extract supplements as the plasma and hepatic thiobarbituric acid reactive substances (TBARS) levels were lowered, whereas the hepatic superoxide dismutase (SOD) and catalase (CAT) activities and glutathione peroxidase (GSH-Px) protein level were elevated. Yam peel extract decreased the level of nitric oxide (NO) production, tumor necrosis factor-alpha (TNF-α), and nuclear factor-kappa B (NF-κB) in CCl4. These results point out that yam peel extract can inhibit lipid peroxidation, enhance the activities of antioxidant enzymes, and decrease the TNF-α/NF-κB level, nitric oxide production, and inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expressions. Therefore, it was speculated that yam peel extract protects rats from liver damage through its anti-inflammation capacity.

Effect of cholestin on toxicity of vitamin A in rats.

A study was undertaken to investigate the effect of cholestin on the toxicity of vitamin A in male wistar rats. The rats were divided into six groups and fed different diets with or without supplement of 1% cholestin and 25,000-50,000 (IU) vitamin A for 2 months. Hence, the symptoms of vitamin A toxicity in rats included loss of body weight, hepatotoxicity and nephrotoxicity. However, these toxic effects of vitamin A were significantly reduced when the rats fed a diet supplemented with cholestin. Furthermore, the level of vitamin A in the serum of rats treated with cholestin and vitamin A was higher than that of the rats treated with vitamin A alone. It indicated that cholestin might play a role in reducing the toxic effect of vitamin A in rats.

Dietary taurine reduces zinc-induced toxicity in male Wistar rats.

Taurine is an agent for treating the heavy metal intoxication and presence of metals such as zinc, copper, and iron may have a role in heavy metal toxicity, a study was undertaken to investigate the effect of taurine on the toxicity of zinc in male Wistar rats. The rats were divided into 8 groups and fed different diets with or without supplement of 5% taurine and 150 to 600 ppm zinc for 2 mo. It was found that the body weight of rats, the ratios of liver and kidney weight to body weight, and the level of glutathione in the liver were decreased with increasing the dose of zinc. The levels of zinc in the liver, kidney, and plasma, the levels of malondialdehyde in the plasma, the levels of thiobarbiture acid-reactive substances in the liver, the activities of aspartate transaminase, alanine transaminase in the plasma, the levels of blood urea nitrogen and creatinine in the plasma of rats were increased with the increasing dose of zinc. Hence, symptoms of zinc toxicity in rats included loss of body weight, hepatotoxicity, and nephrotoxicity. However, these toxic effects of zinc were significantly reduced when the rats fed diet with supplement of taurine. Furthermore, the level of zinc in the feces of rats treated with taurine and zinc was higher than that of rats treated with zinc alone. It indicated that taurine thereby leading to a decreased absorption of dietary zinc and promoted excretion.