Effect of curcumin on tumor necrosis factor-alpha-induced expression and release of monocyte chemoattractant protein-1 in rat astrocytes

Abstract

Objective To investigate the effect of curcumin on tumor necrosis factor-alpha (TNF-α)-in-duced expression and release of monocyte chemoattractant protein-1 (MCP-1) in rat astrocytes.Methods The primary astrocytes were prepared from the cerebral cortex of 5 neonatal Sprague-Dawley rats and cultured.The cultured cells were identified by immunofluorescence staining with glial fibrillary acid protein.The cells were then divided into 6 groups (n =15 each):control group (group C),TNF-α group (group T),TNF-α+ different concentrations of curcumin groups (Cur5,Cur10 and Cur20 groups),and TNF-α+ solvent control group (D group).TNF-α with the final concentration of 20 ng/ml was added and the cells were incubated for 2h in T group.In Cur5,Cur10 and Cur20 groups,curcumin with the final concentrations of 5,10 and 20μmol/L was added,respectively,the cells were incubated for 24h and then the culture medium was abandoned,TNF-α with the final concentration of 20 ng/ml was added and the cells were then incubated for another 2h.In group D,dimethyl sulfoxide with the final concentration of 1 μl/ml was added,the cells were then incubated for 24h,then TNF-α with the final concentration of 20 ng/ml was added and the cells were incubated for another 2h.After treatment in each group,the expression of MCP-1 was determined by immunohistochemistry and the release of MCP-1 was determined by ELISA.Results Compared with group C,the expression and release of MCP-1 was significantly increased in the other five groups (P ＜ 0.05).Compared with group T,the expression and release of MCP-1 was significantly decreased in group Cur20 (P ＜ 0.05),and no significant changes in the expression and release of MCP-1 were found in Cur5,Cur10 and D groups (P ＞ 0.05).Compared with group Cur5,the expression and release of MCP1 was significantly decreased in group Cur20 (P ＜ 0.05),and no significant change in the expression and release of MCP-1 was found in group Cur10 (P ＞ 0.05).Conclusion Curcumin can inhibit TNF-α-induced expression and release of MCP-1 in rat astrocytes and the effect is dose-related and may be one of the mechanisms of curcumin-induced reduction of neurophathic pain. Key words: Curcumin; Astrocytes; Chemokine CCL2 ; Tumor necrosis factor-alpha