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.
ABSTRACT
[ ABSTRACT] AIM: To investigate the role of TNF-αand NF-κB in the mechanism of neuropathic pain due to chronically compressed dorsal root ganglion ( CCD) .METHODS:Based on the CCD model, von Frey filaments were used to quantify behavior test.The expression changes of TNF-αand NF-κB were determined by Western blotting, and the cor-relation between the expression of TNF-αand the 50%paw withdrawal threshold was also analyzed.Moreover, the location of TNF-αin dorsal root ganglion ( DRG) was observed with immunofluorescence double staining.RESULTS: We found 50%paw withdrawal threshold of CCD decreased at the first day after operation.The mechanical allodynia was the most ob-vious at postoperative 7~14 d and lasted longer than 35 d.The expression of TNF-αand NF-κB increased significantly in DRG after operation (P<0.01), especially at 7~14 d, and then restored gradually.Moreover, there was a correlation between the protein expression of TNF-αand the changes of neuropathic behavior ( P<0.05 ) .CONCLUSION: TNF-αand NF-κB are involved in the mechanism of mechanical allodynia after chronically compressed DRG.
