Hepatoprotective and antioxidant effects of single clove garlic against CCl4-induced hepatic damage in rabbits

BACKGROUND The increase in demand and consumption of single clove garlic or 'Solo garlic' (Allium sativum) has resulted in an increase in research on its therapeutic properties. The present study aims to evaluate the antioxidant activities, oxidant-scavenging efficiency and preventive effects of SCG (single clove garlic) and MCG (multi clove garlic) on CCl4-induced acute hepatotoxicity in male rabbits. METHODS For this purpose, rabbits were orally administered with 3 ml of CCl4 /kg of body weight, followed by 0.8 g of MCG or SCG/kg twice a week for three successive weeks. Oxidative hepatotoxicity was then assessed. RESULTS SCG extracts exhibited higher antioxidant capacity than the MCG extract. Scavenging ability of SCG showed significant (p < 0.05) elevation against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide radicals in comparison to MCG. In addition, total phenolic content of SCG was significantly elevated (p < 0.001), thereby suggesting that the composition of garlic storage constituents varies with the number of cloves present. CCl4-induced hepatotoxicity demonstrated histological changes including severe damage in the structure of liver tissues which correlated well to oxidative stress levels. Simultaneously, administration of SCG resulted in a significant reduction of serum alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and total bilirubin (TB) levels in addition to improvement in some histological parameters. Low levels of lipid peroxidation (malondialdehyde, MDA) (p < 0.001), along with a huge reduction in peroxidase (POx) (p < 0.001) revealed protection against oxidative toxicity in the liver homogenate. Higher levels of catalase (CAT) (p < 0.001) and superoxide dismutase (SOD) (p < 0.05) when compared to the MCG test (TM) group indicates that removal of H2O2 is based on CAT activity in SCG test (TS) group rather than the POx activity demonstrated in the former group. CONCLUSION The present study indicates that SCG possesses more protective ability than MCG against CCl4-induced liver injury and might be an effective alternative medicine against acute oxidative liver toxicity.