Abstract: Objective To investigate the effects of total flavonoids of litchi chinensis sonn (TFL) on cell proliferation and the molecular mechanism in rat hepatic stellate cells (HSC-T6) activated by growth factor-β1 (TGF-β1). Methods HSC-T6 cells were treated by 0.25% Trypsin-EDTA and then were digested into single cell suspension by DMEM (10% FBS included), which were mixed with TGF-β1 (5 μg/L). (1) MTT method was used to detect the proliferation of HSC-T6 cells. Cells were cultured in 96-well plate and were treated by different concentrations of TFL including TGF-β1 group, the control group (5‰ DMSO included), and different concentrations of TFL groups (80, 160, 320, 640 and 800 mg/L TFL). Each group has three wells. The absorbance (A) value was measured by enzyme standard meter at the 490 nm wavelength after 24 h, 48 h and 72 h treatment. The cell inhibitory rate was calculated. The subsequent experimental drug concentration and drug treatment time were determined according to half inhibitory concentration (IC50). (2) The expression levels of NF-κB and α-SMA mRNA were detected by PCR (for mRNA) and Western blot assay (for protein). Cells were cultured in the 10 cm culture dish and were divided into different TGF-β1 groups, including TGF-β1 group, the control group (5‰ DMSO included), and different concentrations of TFL groups (125, 250 and 500 mg/L TFL). After 48 h, related indicators were measured. Results At the same treatment time point, with the increased concentrations of TFL, A values were gradually decreased, and the cell inhibitory rates were gradually increased. There were no significant differences in the expressions of NF-κB and α-SMA mRNA between TGF-β1 group and control group. And there were no significant differences in the expressions of NF-κB and α-SMA mRNA between TFL125 group, TGF-β1 group and control group. There was a gradually decrease in the expressions of NF-κB and α-SMA mRNA and protein with the increased concentrations of TFL. Conclusion TFL can inhibit TGF-β1-induced HSC-T6 cell proliferation, which is involved in the inhibited expressions of NF-κB and α-SMA to anti-fibrotic effects in liver fibrosis.

Key words: flavones, liver cirrhosis, rats, NF-kappa B, total flavone of litchi chinensis sonn, hepatic stellate cell, α-smooth muscle actin