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 (5μg/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 andα-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 andα-SMA mRNA between TGF-β1 group and control group. And there were no significant differences in the expressions of NF-κB andα-SMA mRNA between TFL125 group, TGF-β1 group and control group. There was a gradually decrease in the expressions of NF-κB andα-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 andα-SMA to anti-fibrotic effects in liver fibrosis.

Objective: The effect of total flavonoids of litchi (TFL) on nuclear translocation of nuclear factor-kappa B (NF- kappa B) in rat hepatic stellate cell line (HSC-T6) induced by transforming growth factor - beta 1 (TGF- beta 1) in vitro was studied to explore the mechanism of action of anti-hepatic fibrosis drugs. Methods: HSC-T6 was cultured in vitro, induced by TGFβ1 for 24 h, and then treated with TFL at 125, 250 and 500 μg/ml for 48 h. The effect of TFL on NF-κB nuclear translocation in HSC-T6 was observed by confocal laser microscopy. The effects of TFL on the expression of TLR4, p-IκB ɑ, p-NF-κB p65, NF-κB and Collagen I protein were detected by western blot. The expressions of TLR4 and p-NF-κB p65 were detected by immunofluorescence. Data were presented as mean±SEM. Homogeneity test of variance was performed and then followed by one-way analysis of variance (ANOVA). The multiple comparisons between groups were performed by LSD test. P < 0.05 was considered statistically significant. Results: Confocal laser scanning microscopy showed TFL inhibited the nuclear translocation of NF-κB in activated HSC-T6 in a concentration-dependent manner and TFL down regulated the protein expression levels of TLR4, p-IκB ɑ, p-NF-κB p65, NF-κB and collagen I protein in HSC-T6 in a concentration-dependent manner. Conclusion The mechanism of TFL against hepatic fibrosis may be related to the inhibition of nuclear translocation of NF-κb in the activated HSC-T6 and the expression of TLR4, P-iκbɑ, P-nf-κb p65, NF-κb and collagen I protein in HSC-T6.