[Sophoridine suppresses inflammatory cytokine secretion by lipopolysaccharide-induced RAW264.7 cells and its mechanism].

OBJECTIVE

To observe the effects of sophoridine on lipopolysaccharide (LPS)-induced secretion of tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β) as well as the expressions of Toll-like receptor 4 (TLR4) and c-Jun in RAW264.7 cells and explore the molecular mechanism of anti-LPS of sophoridine.

METHODS

RAW264.7 cells were cultured and divided into four groups: macrophage control group (using serum-free DMEM to incubate cells), sophoridine control group (using 31.25 mg/L sophoridine-added DMEM to incubate cells), LPS group and sophoridine intervention group (using 100 μg/L LPS DMEM to incubate cells for 60 minutes, then throwing away LPS and adding serum-free DMEM or 31.25 mg/L sophoridine DMEM to incubate cells). Cells and culture medium were collected respectively at 5, 30, 60 and 120 minutes after the above treatment. The expression levels of TLR4 and c-Jun mRNA were determined by reverse transcription PCR (RT-PCR), and the expression of c-Jun protein in RAW264.7 cells was measured by immunocytochemistry and Western blotting; The levels of TNF-α and IL-1β in cell culture medium were analyzed by ELISA.

RESULTS

Compared with macrophage control group, sophoridine control group had no statistical difference in each index. Compared with macrophage control group, the expressions of TLR4 mRNA, c-Jun mRNA and protein as well as the secretion of TNF-α and IL-1β significantly increased at each time point in LPS group, and maintained the level to 120 minutes. Sophoridine suppressed the expressions of TLR4 mRNA, c-Jun mRNA and protein, and reduced the secretion of TNF-α and IL-1β in LPS-stimulated RAW264.7 cells in sophoridine intervention group.

CONCLUSION

Sophoridine down-regulated the secretion of TNF-α and IL-1β in LPS-induced RAW264.7 cells via inhibiting the expressions of TLR4 and c-Jun.