Abstract: Objective: To compare in vitro effects of (+)-catechin (Cat) and epigallocatechin gallate (EGCG) on ethanol (ETOH)-induced aberrant lipid metabolism and oxidative stress in HepG2 cells. Methods: HepG2 cells were divided into six groups: normal, 200 μmol/L (+)-Cat, 200 μmol/L EGCG, 300 mmol/L ETOH treatment, 200 μmol/L (+)-Cat plus 300 mmol/L ETOH treatment, and 200 μmol/L EGCG plus 300 mmol/L ETOH treatment. All groups were cultured at 37 ℃ for 24 h. Thereafter, the contents of triglyceride and malondialdehyde (MDA) and superoxide dismutase (SOD) activity were determined. The morphology of lipid droplets in HepG2 cells in each group was observed by Oil Red O staining. The mRNA expression of sterol regulatory element binding protein 1 (SREBP-1), peroxisomal proliferators activate receptors α (PPARα), carnityltransferase 1 (CPT1) and diacylglyceryltransferase 2 (DGAT2) in HepG2 cells were measured by fluorescence quantitative polymerase chain reaction. Results: The level of oxidative stress and TG content in ETOH-treated cells were significantly higher than those in the normal, (+)-Cat and EGCG groups. The oxidative stress response in the (+)-Cat plus ETOH and EGCG plus ETOH groups was significantly improved, and TG content was significantly lower in the two groups than in the ETOH group (P < 0.05, P < 0.01). Moreover, the mRNA expression of SREBP-1 and DGAT2 was down-regulated (P < 0.05, P < 0.01) , and the mRNA expression of PPARα and CPT1 was up-regulated (P < 0.05, P < 0.01). Conclusion: Both (+)-Cat and EGCG can improve ETOH-induced oxidative stress and lipid metabolism disorders in HepG2 cells, and EGCG is more effective.

Key words: (+)-catechin; epigallocatechin gallate; lipid metabolism; oxidative stress