Abstract:

Objective: To evaluate the in vitro antioxidant activities of anthocyanins extracted from purple sweet potato
and investigate the protective effect of the anthocyanins on H2O2-induced oxidative stress in HepG2 cells. Methods: The
anthocyanins were extracted and purified from the dried powder of purple sweet potato. The total reducing power, free
radical scavenging effect and red blood cell hemolysis-protecting effect of the anthocyanins were measured. Moreover,
an in vitro HepG2 cell damage model induced by H2O2 was established, and the MTT (3-(4,5-dimethylthiazol-2-yl)-
2,5-diphenyltetrazolium bromide) method was used to detect the protective effect on HepG2 cell injury of different
concentrations of the anthocyanins. Results: The anthocyanins had good in vitro antioxidant effects, possessing reducing
power similar to that of VC and potent scavenging activities hydroxyl and superoxide anion radicals in a dose-dependent
manner. The superoxide anion radical scavenging activity was higher than that of BHT at the same concentration. The
anthocyanin extract at 50–1 600 μg/mL could restrain the HepG2 cells from apoptosis caused by H2O2 and it at 800 μg/mL
yielded a survival rate of HepG2 cells of (88.03 ± 7.48) %. Conclusion: The anthocyanins from purple sweet potato possess
good in vitro antioxidant ability and obvious protective effects on HepG2 cells from oxidative stress injury induced by H2O2.

Key words: anthocyanins from purple sweet potato, antioxidant, free radicals, oxidative stress injury, HepG2 cells