Total flavonoids of Epimedium attenuate aging-related inflammation in rat brain by inhibiting MAPK/NF-κB signaling pathway / 中国药理学通报

ABSTRACT

Aim To investigate the effect of the total flavonoids of Epimedium (TFE)on MAPK/NF-κB sig-naling pathway and the inflammatory reaction in the hippocampus of natural aging male rats.Methods The morphological changes of the hippocampus com-posed of three areas (CA1 ,CA3 and DG)were ob-served using haematoxylin-eoin (HE ) staining.The protein expression levels of senescence-associated pro-tein p21,apoptosis-related proteins Bax and Bcl-2, nuclear transcription factor-κB p65 (NF-κB p65 )and its downstream inflammatory factors TNF-α,IL-1βand COX-2,and MAPK signaling pathway-related proteins (ERK1/2,p-ERK1/2,JNK,p-JNK,p38MAPK,p-p38MAPK)in hippocampal were detected by Western blot.Results Compared with natural aging group, TFE obviously improved the morphology and structure of hippocampal neurons,and the nerve cells arranged neatly and closely. Furthermore, TFE significantly downregulated the protein expression levels of p2 1 and Bax,upregulated the protein expression levels of Bcl-2 and the ratio of Bcl-2/Bax,and reduced the expression of NF-κB p65 and of its downstream inflammatory fac-tors TNF-α, IL-1β, COX-2, and MAPK signaling pathway-related proteins (p-ERK1/2,p-JNK and p-p38 MAPK ) in hippocampus of natural aging rats. Conclusions TFE effectively protects against inflam-matory reaction in brain aging of SD male rats.The mechanism is related with inhibition of NF-κB nuclear translocation and reduction of its downstream inflamma-tory cytokines expression by inhibiting MAPK signaling pathway activation.