Hepatic oxidant/antioxidant status in cholesterol-fed rabbits: Effects of garlic extract

The investigation of oxidant/antioxidant status in hepatic tissues from cholesterol-fed rabbits and the establishment of possible protective effects of aqueous garlic extract on cholesterol-induced hepatic steatosis.

Twenty-two of 31 white New Zealand rabbits were given cholesterol (0.5 g/kg/day) for 4 months. Seven of them were then killed (cholesterol group). The remaining 15 animals were divided into two groups. Seven were fed on a normal laboratory diet (normal diet group) and the others (extract group) on a normal diet plus garlic extract (1.5 ml/kg/day) for an additional 3 months. Superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT) enzyme activities, antioxidant potential (AOP) value, malondialdehyde (MDA), cholesterol and triglyceride levels in the liver tissues and total cholesterol and triglyceride levels in serum samples were measured. An histological evaluation was also done.

An impaired antioxidant system, reduced antioxidant defence potential and increased peroxidation were found in hepatic steatotic tissues from cholesterol-fed animals. Treatment with garlic extract caused a significant increase in antioxidant potential and partly eliminated peroxidation damage in the hepatic tissue. Additionally, the extract caused significant reductions in the cholesterol levels of blood and hepatic tissues. The histological evaluations were in accordance with these results.

The results suggest that cholesterol-induced steatosis leads to a weakened antioxidant defence system and causes peroxidation in the hepatic tissue. Treatment with garlic extract may contribute to significant amelioration in the hepatic steatosis and peroxidation processes.