Abstract: Objective To investigate the role of the ROS/MAPK signaling axis in mediating the inhibitory effect of eriocitrin on proliferation and migration of hepatocellular carcinoma SMMC-7721 cells. Methods SMMC-7721 cells were treated with different concentrations of eriocitrin for 24 h, and the changes in cell viability were detected with CCK-8 assay. The migration and invasion abilities of the treated cells were evaluated using Transwell and scratch healing assays, the cell proliferation was assessed with colony- forming assay, and changes in nuclear morphology were observed with DAPI staining. Western blotting was performed to examine the changes in the expressions of E-cadherin, N-cadherin, MMP-2, MMP-9, PARP, Pro-caspase 3, p-JNK, p-P38, and p-ERK. The effect of eriocitrin on PARP cleavage in SMMC-7721 cells pretreated with ERK, JNK and P38 inhibitors (U0126, SB203580 and SP600125, respectively) was detected using Western blotting. The effect of treatment with N-acetyl-cysteine (NAC, 30 μmol/L) and eriocitrin (100, 200, and 300 μg/mL), alone or in combination, on reactive oxygen species (ROS) levels in the cells was examined using a DCFH-DA fluorescent probe. Results Eriocitrin below 50 μg/mL did not produce significant effect on the viability of SMMC-7721 cells (P>0.05). Treatment with eriocitrin significantly inhibited scratch healing, migration, and colony formation of the cells (P<0.01), reduced the protein expressions of N-cadherin, MMP-2, and MMP-9 (P<0.01), and up-regulated E-cadherin protein expression (P<0.05). Eriocitrin-treated SMMC-7721 cells showed obvious apoptotic morphologies with decreased Pro- caspase 3 expression and increased PARP cleavage (P<0.01) and phosphorylation levels of JNK, P38, and ERK (P<0.01); Eriocitrin-induced PAPR cleavage was obviously enhanced by U0126 and SB203580 but attenuated by SP600125. Treatment with 300 μg/mL eriocitrin for 30 min significantly increased ROS level in the cells, and this effect was obviously suppressed by NAC. Conclusion Eriocitrin can suppress the proliferation and migration and promote apoptosis of hepatocellular carcinoma SMMC-7721 cells by promoting ROS production and activating the MAPKs signaling pathway.

Key words: eriocitrin; SMMC-7721; reactive oxygen species; MAPKs