Protective Role of Tetrahydrocurcumin: an Active Polyphenolic Curcuminoid on Cadmium-InducedOxidative Damage in Rats

In the present work, protective effect of tetrahydrocurcumin (THC) against oxidative damages in cadmium (Cd)-induced toxicity in rats was evaluated. Cd is an important environmental and industrial toxicant that affects almost all the organs, especially liver. Liver is the major organ responsible for the metabolism and the primary target for many toxic chemicals and drugs. Effect of THC, the curcumin-derived polyphenolic compound on Cd-induced oxidative stress and hepatic damage was evaluated using male albino Wistar rats. In Cd-administered rats (5 mg/kg body weight (b.w.), orally for 4 weeks), activities of aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and gamma glutamyl transferase (GGT) were significantly increased in serum with the elevated level of bilirubin. Red blood cells (RBC), haemoglobin contents and haematocrit values were also significantly decreased in Cd-treated rats. In addition, the levels of lipid peroxidation markers like thiobarbituric acid reactive substances (TBARS), lipid hydroperoxides (LHP), protein carbonyl contents (PCC) and conjugated dienes (CD) were significantly increased followed by the significant decrease in the levels of reduced glutathione (GSH), total sulphydryl groups (TSH), ascorbic acid (vitamin C) and vitamin E in liver of Cd-administered rats. Oral administration of THC (20, 40 and 80 mg/kg b.w.) followed by Cd for 4 weeks showed a significant restoration of the above changes to near normal. Histopathological changes observed in Cd intoxicated hepatic tissues were minimized on treatment with THC. This study suggests that THC at the dose of 80 mg/kg b.w. effectively subdues the Cd-induced toxicity and controls the free radical-induced liver damage in rats.