Potential Chemoprevention of Liver Disorders by Dietary Curcumin in Rats Treated with Benzo(a)pyrene

 Curcumin, which is a naturally occurring compound, is present in turmeric (Curcuma longa L., family Zingiberaceae) rhizomes, possesses both anti-inflammatory and antioxidant properties, and has been tested for its chemopreventive properties in skin, forestomach and colon carcinogenesis. The present study was designed to investigate the potential chemopreventive actions of dietary curcumin on Benzo(a)pyrene [P(a)P] induced liver disorders/toxicity  and also the modulating effects of this agent on liver functions, oxidants and antioxidant status, immunological parameters in male albino  rats, weighing 150±8.7 g per each. Groups of animals were fed the control (modified AIN-76A) diet or a diet containing 500-2000 mg/kg of curcumin. After two weeks, all animals, except those in the negative group (vehicle/normal saline treated group) were given two weekly s.c. injections of B(a)P  at a dose 15 mg/5 ml/kg body weight). All groups were continued on their respective dietary regimen until the termination of the experiment at 12 weeks. The results indicate that treatment of animals with B[a]P caused a significant increased (p≤0.01) in AST (110.38%), ALT (67.85%) and ALP (116.47%) compared to normal controls. Dietary administration of curcumin (500 to 1000 mg/kg w/w) significantly ((p≤0.01) inhibited serum AST, ALT and ALP activities by different rates. The same behavior was recorded for malondialdehyde (MDA) and nitrite (NO2) levels in liver tissues, the biomarkers of oxidative stress in cells and some immunological parameters including albumin levels and protease activity in serum.  The opposite direction was recorded for the glutathione fractions (biological macromolecules antioxidant) in liver tissues. These results supported our hypothesis that dietary curcumin is able to prevent or inhibit B[a]P hepatotoxicity through modulating liver serum enzymes activity, formation of liver MDA and NO2 and serum immunological parameters . Therefore, we recommended curcumin by a concentration up to 2000 mg/kg to be included in our daily diets, drinks and food products. Keywords: Turmeric, curcumin, liver tissues, liver functions, glutathione fractions,   immunological parameters, malondialdehyde  and nitrite.