Effect of carotenoids against genotoxicity of diethylnitrosamine on rat hepatocytes

Carotenoids have been considered as special nutrients due to their biological activity as provitamin A compounds, and because of their natural antioxidant and anticarcinogenic properties. The main objective of this study was to evaluate the protective effect of carotenoids against the genotoxic cellular damage induced by diethylnitrosamine (DEN), a potent hepatocarcinogen. Normal and freshly isolated hepatocytes were cultured as the biological system. Concentrations of 2.5 and 5 μM DEN caused 1.3 and 2.0 times more DNA T³H incorporation, respectively, when compared with control cells. Pure carotenoids, β-carotene (50 μM), lutein (1 μM) and a carotenoid extract from green peppers (1 μM eq. lutein) were used as functional nutrients to protect the cells. All the carotenoids studied prevented the genotoxic damage caused by 2.5 μM DEN. When 5 μM DEN was used, only β-carotene and the pepper extract inhibited the damage up to 30- 40%. Carotenoids provide a dose-dependent protective effect against DNA damage induced by DEN in isolated hepatocytes.