Effect of Seabuckthorn leaves on Antioxidant and Microsomal Enzymes in poultry birds

In vivo studies on broiler birds were carried out to evaluate effect of aflatoxin and seabuckthorn leaves on microsomal enzyme system, antioxidant enzymes and biochemical parameters i.e. serum triglyceride, total plasma protein, aminopyrine demethylase, aniline hydroxylase, NADPH cytochrome P450 reductase, catalase, LPO, superoxide dismutase, GSH, blood urea nitrogen (BUN) and creatinine levels in poultry. The poultry birds were divided into six groups containing six birds each. Aflatoxin (400 ppb) and seabuckthorn leaves (10000ppm) was administered continuously in poultry feed. Aflatoxin increased serum triglyceride, blood urea nitrogen and creatinine levels where as seabuckthorn leaves supplementation at 10000ppm significantly decreased triglyceride (P<0.05), blood urea nitrogen (P<0.05) and creatinine levels in birds. Toxin decreased liver, kidney and blood superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) activity, whereas, seabuckthorn leaves (SBTL) increased the activity of these enzymes as compared to control group. The level of lipid peroxidation was significantly increased in the toxin exposed group and decreased in case of SBTL. The activity of Aminopyrine demethylase and Aniline hydroxylase increased, while the activity of NADPH cytochrome P450 reductase is decreased in case of toxin group whereas in case of seabuckthorn leaves exposed group showed no significant change in case of aminopyrine demethylase and NADPH cytochrome P450 reductase, however, the activity of Aniline hydroxylase decreased. On the basis of present study, it could be concluded that the seabuckthorn leaves reduced the effect of Aflatoxin which produced oxidative stress by altering the levels of antioxidant enzymes of liver and kidney in adult poultry birds

Medicinal herb, Thonningia sanguinea protects against aflatoxin B1 acute hepatotoxicity in Fischer 344 rats

1. Thonningia sanguinea, a plant used prophylactically against bronchial asthma in Ghana was recently found to have antioxidative and hepatoprotective actions in our laboratory. 2. In this study, the effect of T. sanguinea extract on certain biochemical indices in serum and liver of Fischer 344 rats given a single intraperitoneal (i.p.) dose (1 mg/kg) of aflatoxin B1 (AFB1) was investigated. 3. Administration of AFB1 resulted in significant increases in serum alanine aminotransferase (ALT) and glutathione S-transferase (GST) levels and a signifi-cant decrease in aniline hydroxylase activity in liver microsomes. When T. sanguinea (5 ml/kg) was intraperitoneally administered to rats 12 h and 1 h before AFB1, liver injury was significantly reduced as seen in the decreased levels of serum ALT and serum GST. However, the decrease in aniline hydroxylase activity by AFB1 was not recovered but enhanced by T. sanguinea pre-treatment. 4. Kinetic analysis of cytochrome P450 activity of rat liver microsomes in vitro demonstrated that T. sanguinea inhibited aniline hydroxylase non-competitively suggesting depression of biotransformation of AFB1 to toxic metabolites. 5. The data indicate a hepatoprotective action of T. sanguinea against AFB1-induced liver injury.

Modulation of Microsomal Cytochrome P450 by Scutellariae Radix and Gentianae Scabrae Radix in Rat Liver

The present study has determined the effects of Scutellariae Radix (Huangqin) and Gentianae scabrae Radix (Longdan) on liver microsomal cytochrome P450 (P450)-dependent mono-oxygenases using rats pretreated with crude extracts of medicinal herbs. Scutellariae Radix resulted in a 53% decrease of pentoxyresorufin O-dealkylase activity in liver microsomes. In contrast, Gentianae scabrae Radix caused a 50% increase of benzo(a)pyrene hydroxylase activity. Immunoblotting 1A and 2B proteins, respectively. Scutellariae and Gentianae scabrae Radixes had no effects on microsomal aniline hydroxylase activity and P450 2E1 protein.

Differential effects of blood insulin levels on microsomal enzyme activities from hepatic and extrahepatic tissues of male rats

Microsomal glutathione S-transferase, UDP-glucuronyl transferase, and aniline hydroxylase activities were determined in liver, renal cortex, and small intestine of control, streptozotocin-diabetic, alloxan-diabetic, and untreated insulin-injected male Wistar rats. Renal microsomal glutathione S-transferase activity showed a direct linear relationship with insulin blood levels, in agreement with our previous report on cytosolic glutathione S-transferase. This result suggests a possible regulatory mechanism of insulin that needs to be further examined. The hepatic microsomal UDP-glucuronyl transferase was only decreased in streptozotocin-diabetic rats and was not restored by insulin treatment. Intestinal UDP-glucuronyl transferase exhibited an opposite response in streptozotocin-treated animals that was not normalized by the administration of insulin. Hepatic aniline hydroxylase showed the same behaviour as intestinal UDP-glucuronyl transferase. These results suggest that streptozotocin and (or) its metabolites have a direct effect on hepatic and intestinal UDP-glucuronyl transferase activity and on hepatic aniline hydroxylase activity. On the other hand, insulin regulation of enzyme activity varies from one organ to another.Key words: insulin, streptozotocin, alloxan, glutathione S-transferase, UDP-glucuronyl transferase, aniline hydroxylase.