Effects of N-trans-feruloyltyramine isolated from laba garlic on antioxidant, cytotoxic activities and H2O2-induced oxidative damage in HepG2 and L02 cells

Laba garlic is a kind of processed garlic products, it is the traditional Chinese food with a long history. In this study, the antitumor, antioxidant and cytotoxic properties of the blue pigment (BP) from Laba garlic were investigated. N-trans-feruloyltyramine (FLA) was isolated and identified from BP. The protective effects of FLA against H2O2-induced oxidative damages in L02 cells were also assessed. The apoptotic effects of FLA were detected by using flow cytometry analysis. Results showed that the tumor growth was significantly suppressed by BP (P < 0.05). BP and FLA exhibited remarkable antioxidant activities. L02 cells pretreatment with FLA could significantly fight against the oxidative damage induced by H2O2, inhibit the morphological changes of mitochondria and maintain the integrity of mitochondria. FLA showed proliferation inhibition on HepG2 cells with IC50 value of 194 +/- 0.894 mu M. After treatment of FLA (320 mu M), the results of MTT assay on HepG2 and L02 cells indicated that FLA had selective cytotoxic effects. It suggested a new way of prevention and treatment of tumors and FLA might be a promising candidate in cancer therapy and functional foods.