Effect of carotenoids and ascorbic acid of Japanese persimmons on cellular lipid peroxidation in HepG2 cells

In this experiment, we examine the functional property of carotenoids; beta-cryptoxanthin (Cry), zeaxanthin (Zea), beta-carotene (Car)) and ascorbic acid (AsA). The accumulation amounts of Cry, Zea and Car in HepG2 cells cultured in the high concentration medium were larger than that in a low concentration. Further those accumulation amounts in long incubation time within 24 hours were greater than that in a shorter time. When the added carotenoid concentration, with or without hydrogen peroxide, increased from 0 to 5 microM in the culture medium, the thiobarbituric acid reaction substance (TBARS) values in the HepG2 cells decreased significantly (p < 0.05). The decrease of TBARS values shows the antioxidative property of the carotenoids. When AsA and Tocopherol(Toc) were added to the medium from 0 to 20 microM, the TBARS values, with or without hydrogen peroxide, decreased significantly with increasing concentrations of AsA and Toc respectively (p < 0.05). The decreased amount of TBARS in 5 microM Cry compared with control(0 microM) was the largest among 6 antioxidants (Cry, Car, Zea, Retinol(Ret), AsA, Toc) used in this experiment.