Inhibitory effect of madecassoside on LPS-stimulated microglia / 中国病理生理杂志

ABSTRACT

[ ABSTRACT] AIM:To observe the inhibitory effect of madecassoside on the LPS-stimulated microglia and to inves-tigate its possible mechanism.METHODS:Microglia cells of neonatal Sprague-Dawley ( SD) rats were cultured, isolated and purified.Microglia cells were activated with lipopolysaccharide ( LPS) .The inhibitory effect of madecassoside on micro-glia was measured by MTT assay.Tumor necrosis factor alpha (TNF-α), interleukin 1β(IL-1β) were detected by ELISA. Cell cycle and apoptotic rate were evaluated by flow cytometry.The expression of TLR4 was detected by Western blotting. The expression of NF-κB was detected by RT-PCR.RESULTS: LPS induced the proliferation of microglia and release in-flammatory cytokines significantly.Compared with LPS group, madecassoside inhibited the proliferation of microglia induced by LPS in a dose dependent manner.The IC50 value of madecassoside was 10.97 nmol/L to microglia after incubation for 48 h.Madecassoside also decreased the levels of TNF-αand IL-6, increased the ratios of microglia at the G2 phase and the ap-optotic rate, decreased the expression of TLR4 and NF-κB significantly (P<0.05).CONCLUSION:Madecassoside has in-hibitory effects on the proliferation of LPS-stimulated microglia, by which the mechanism may be related to inhibition of the expression of TLR4 and NF-κB, change of cell cycle distribution and induction of microglia apoptosis.