The objective of present study was to investigate the anti oxidative and hepatoprotective effects of tomato extracts. Total antioxidant capacity and total antioxidant response were 5.5 and 19.8μg Trolox equivalent per mg of tomato extract, respectively. DPPH radical scavenging activity of tomato extracts (10mg ml-1) was 70% as compared to 100% by pyrogallol solution as a reference. The effect of the tomato extracts on lipid peroxidation was examined using rat liver mitochondria induced by iron/ascorbate. Tomato extracts at the concentration of 0.5mg ml-1 significantly decreased TBARS concentration. Tomato extracts prevented lipid peroxidation in a dose-dependent manner. The effect of the tomato extracts on reactive oxygen species (ROS) generation was examined using cell-free system induced by H2O2/FeSO4. Addition of 1mg ml-1 of tomato extracts significantly reduced dichlorofluorescein (DCF) fluorescence. Tomato extracts caused concentration-dependent attenuation of the increase in DCF fluorescence, indicating that tomato extracts significantly prevented ROS generation in vitro. The effect of tomato extracts on cell viability and proliferation was examined using hepatocyte culture. Primary cultures of rat hepatocytes were incubated with 1mM tert-butyl hydroperoxide (t-BHP) for 90 min in the presence or absence of tomato extracts. MTT values by addition of tomato extracts at the concentration of 2, 10, and 20mg ml-1 in the presence of t-BHP were 13, 33 and 48%, respectively, compared to 100% as control. Tomato extracts increased cell viability in a dose-dependent manner. These results demonstrate that tomato extracts suppressed lipid peroxidation and t-BHP-induced hepatotoxicity and scavenged ROS generation. Thus antioxidant and hepatoprotective effects of tomato extracts seem to be due to, at least in part, the prevention from free radicals-induced oxidation, followed by inhibition of lipid peroxidation.

• Tae-Jin Rhim