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Objective: To investigate the effect of Duyun Maojian tea extract on the proliferation of human hepatic stellate cells and its mechanism. Methods: Human hepatic stellate cells (LX-2) were cultured in vitro and they were treated with 0, 5, 10, 20, 40, 80, 160, 320, and 640 μg/mL Duyun Maojian tea extracts for 24 h, respectively. The cells were collected and the cells' activity were detected by CCK-8 method. The concentration of Duyun Maojian tea extract was selected when the concentration of Duyun Maojian tea extract was lower than the half inhibitory activity (IC50) of LX-2 cells, and the subsequent experiment was conducted. In addition, LX-2 cells were randomly divided into the blank control group, model group, low-, medium-, high-concentration tea extract groups and positive control group. Cells in the blank control group were given routine culture for 26 h without any other treatment； cells in the model group were pretreated with 0. 5 μg/mL lipopolysaccharide (LPS) for 2 h, followed by routine culture for 24 h； cells in the low-, medium- and high-concentration tea extracts groups were pretreated with 0. 5 μg/mL LPS for 2 hours, followed by treatment of low-, medium- and high-concentration tea extracts for 24 h； cells in the positive control group were pretreated with 0. 5 μg/mL LPS for 2 h and then they were treated with 5 μmol/L silybin for 24 h. The expression levels of inflammatory cytokines such as interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and cyclooxygenase-2 (COX-2) mRNA were detected by RT-qPCR, and the protein expression levels of inflammatory cytokines such as IL-6, TNF- α, COX-2 and nuclear factor kappa-B (NF-κB) signal pathway NF-κB p65, p-NF-κB p65, IκBα, and p-IκBα were detected by West⁃ ern blotting. Results: The Duyun Maojian tea extracts of 0, 5, 10, 20, 40, 80, 160, 320, 640 μg/mL inhibited the activity of LX-2 cells in a concentration-dependent manner (F=60. 160, P<0. 01) . When LX-2 cells were in IC50, the con⁃ centration of Duyun Maojian tea extract was 170. 9 μg/mL. Although the LX-2 cell activity decreased after the interven⁃ tion of 5, 10, 20 μg/mL Duyun Maojian tea extracts, there was no significant difference in comparison with that of 0 μg/mL Duyun maojian tea extract (all P>0. 05) . Therefore, 40, 80, 160 μg/mL Duyun Maojian tea extracts were selected as low-, medium- and high-concentration tea extracts groups for the following experiments. Compared with the blank control group, the expression levels of inflammatory cytokines IL-6, TNF-α, COX-2 mRNA and protein in the model group increased significantly (all P<0. 05) . Compared with the model group, the expression levels of IL-6, TNF-α, COX-2 mRNA and protein decreased significantly in the low-, medium- and high-concentration Duyun Maojian tea extracts groups (all P<0. 05) . Compared with the blank control group, the protein expression levels of p-NF-κB p65 and p-IκBα of NF-κB signal pathway increased significantly in the model group (all P<0. 05) . Compared with the model group, the protein expression levels of p-NF-κB p65 and p-IκBα decreased significantly in the low-, medium- and high-concentration Duyun Maojian tea extracts groups (all P<0. 05) . Conclusion: Duyun Maojian tea extract can inhibit the proliferation of human hepatic stellate cells, and the mechanism may be related to inhibiting the activation of NF-κB signaling pathway and reducing the production of inflammatory factors. [ABSTRACT FROM AUTHOR]

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