Effect of SAaB on the release of inflammatory factors induced by lipopolysaccharide in cultured astrocytes in rats

Aim To investigate whether Saponins from Anemarrhena asphdeloids Bge(SAaB) can protect cortical astrocytes from lipopolysaccharide(LPS)-in-duced release of inflammatory factors and to study the mechanisms responsible for this protective effect.Methods Cultured astrocytes were treated with LPS(10 mg·L-1) for 24 h,in the Absence or presence of SAaB(1,10 and 100 μmol·L-1) or the specific inhibitor of JNK SP600125(10 μmol·L-1),and harvested.Tumor necrosis factor-α(TNF-α) and nitric oxide(NO) generation were analysed respectively by ELISA and Griess technology.Western blot was performed to observe the level of phospho-JNK and phospho-c-Jun in cultured astrocytes.Immunofluorescent technology was performed to observe the level of phospho-activating transcription factor-2(ATF-2) protein expression.Results LPS induced a significant increase in phospho-JNK and phospho-c-Jun protein expression without affecting total protein levels,and increased the expression of phospho-ATF-2 and the release of TNF-α and NO in cultured astrocytes in rats.SP600125 significantly inhibited LPS-induced increase in the release of TNF-α and NO.SAaB obviously inhibited LPS-induced increase in the release of TNF-α and NO and the expression of phospho-JNK,phospho-c-Jun and phospho-ATF-2 protein in cultured astrocytes.Conclusion This study indicates that SAaB can inhibit the release of TNF-α and NO induced by LPS in cultured astrocytes through the suppression of JNK signal transduction pathway activity.