OBJECTIVETo investigate the effect of Fuzhenghuayu compound (FZHc) on expression of nuclear factor E2-related factor 2 (Nrf2) in hepatocytes under conditions of hepatic fibrosis using a mouse model.

METHODSMice were randomly assigned to a control group and a hepatic fibrosis model group. The control group was further divided into three subgroups for use as normal controls (A1), mineral oil-treated controls (A2), and FZHc-treated controls (A3); the hepatic fibrosis model group was administered carbon tetrachloride (CC14 dissolved in mineral oil and injected intraperitoneally) and further divided into four subgroups for use as 6-weeks models (B1), 10-weeks models (B2), low-dose (L)-FZHc models (C1), and high-dose (H)-FZHc models (C2). The FZHc (capsule powder diluted with double-distilled water to 0.1 g/mL) was administered via gastric perfusion to groups A3, C1, and C2 starting at week 7 of the experiment. At the end of week 6 and 10, hepatic specimens were collected and evaluated for degree of hepatic fibrosis and inflammation using routine haematoxylin-eosin staining and Masson staining. Immunohistochemical analysis was performed to measure the hepatocyte expression of Nrf2, NAD(P)H quinine oxidoreductase 1 (Nqol), a-smooth muscle actin (a-SMA) and fibronectin (FN). Real-time fluorescence quantitative PCR was used to measure Nrf2 mRNA expression. Western blotting was used to detect Nrf2 and Nqol total protein expression and Nrf2 nuclear translocation. F test, LSD test and ridit test were used for statistical analyses.

RESULTSCompared with the B2 group (ridit value: 0.09), the model groups treated with FZHc showed significantly lower degrees of hepatic inflammation and fibrosis for both the low (C1 group, ridit value: 0.32) and high doses (C2 group, ridit value: 0.40) (F =82.927, P less than 0.05). In addition, compared with the B2 group, the model groups treated with FZHc showed significantly decreased expression of a-SMA and FN proteins, with a dose-dependent trend (by immunohistochemistry: C 1 group at the end of 10 weeks, F =77.421, 118.262, P less than 0.05; C2 group, P =0.002, 0.013) and significantly increased expression of Nrf2 and Nqol proteins (by immunohistochemistry:C1 and C2 groups at the end of 10 weeks, F =182.537, 75.615, P less than 0.05 and by westen blotting: F =45.664, 127.673, P less than 0.05), which also showed a dose-dependent trend (C2 group, P =0.000, 0.014; 0.005, 0.014). Western blotting also indicated that the amount of nuclear transported Nrf2 was higher in the C1 and C2 groups at the end of 10 weeks (vs. B2 group, F =94.787, P less than 0.05), and the amount of nuclear transported Nrf2 was significantly higher in the C2 group (vs. C1 group, P =0.044). Nrf2 mRNA expression was significantly higher in the C1 group than in the B2 group (F =3230.105, P less than 0.05), and the C2 group had more substantially increased expression (P =0.001); there was no statistical difference found between groups B1 and B2 (P =0.094).

CONCLUSIONFuzhenghuayu compound increased the expression of Nrf2 mRNA and protein under conditions of hepatic fibrosis in mice and stimulated Nrf2 nuclear transport, as well as increased expression of the Nrf2 target gene Nqol that is known to suppress activation of hepatic stellate cells and decrease the deposition of FN. Therefore, Fuzhenghuayu compound may ameliorate hepatocyte injury in hepatic fibrosis in mice by exerting an antihepatic fibrosis effect.