Influence of PC-B2 on oxidative DNA damage induced by AFB1 and repair gene expression in hepatocytes

Objective To investigate the effect of procyanidin B2(PC-B2)on oxidative DNA damage induced by aflaoxin B₁(AFB₁)and repair gene expression in hepatocytes. Methods Well grown L-02 cells in logarithmic phase were divided into control group, dimethyl sulfoxide (DMSO) group, AFB₁ exposure groups (10, 20, 30, and 40 μg/mL), PC-B2 exposure groups (3, 10, and 30 μg/mL), and PC-B2 intervention groups (3, 10, and 30 μg/mL PC-B2+30 μg/mL AFB₁).Cell proliferation and the levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG) in cell culture supernatant and cellular human 8-oxoguanine DNA glycosylase-1 (hOGG1) expression were assayed with 3-(4, 5-dimethylthiazolyl)-2, 5-diphenyltetrazolium bromide (MTT), enzyme-linked immunosorbent assay (ELISA), and quantitative PCR (qPCR) method. Results The cell proliferation in AFB₁ exposure groups was significantly inhibited, with a dose-effect relationship(P < 0.05).Compared with that of DMSO group, the cell proliferation (69.9±2.46%) was obviously decreased and the content of 8-OhdG (2.779±0.089 ng/mL)was significantly increased in 30 μg/mL AFB₁ exposure group (P < 0.05).Compared with 30 μg/mL AFB₁ exposure group, the cell proliferations (70.6±2.67%, 69.7±1.94%, and 82.4±1.58%)were increased and the contents of 8-OHdG (2.550±0.078, 2.376±0.109, and 1.873±0.065 ng/mL) were significantly decreased in the three PC-B2 treatment groups (all P < 0.05);the expression of hOGG1 decreased in the 30 μg/mL AFB₁ treatment group, but it obviously increased after the treatment of PC-B2 (P < 0.05). Conclusion PC-B2 has the effect of increasing the proliferation of hepatocyte and inhibiting oxidative DNA damage induced by AFB₁.The antioxidant activity may related to hOGG1 gene expression levels.