Anti-inflammatory effect of corynoline isolated from Corydalis bungeana Turcz.

To isolate corynoline from Corydalis bungeana Turcz. and study its anti-inflammatory mechanism via TLRs/NF-κB signal pathway. Corynoline was extracted by 80% ethanol and purified by silicagel column chromatography. The structure and purity of corynoline was determined by UPLC, MS, ¹H NMR and ¹³C NMR. In the course of experiment, the cytotoxicity of corynoline was evaluated by MTT assay. And the inflammation model was established by RAW264. 7 macrophages induced by lipopolysaccharide(LPS), which was intervened by corynoline. The expression levels of TLR4, TLR2 and nuclear transcription factor-κB(NF-κB)signaling pathways related proteinsin RAW264. 7 macrophages were detected by Western blot. Furthermore, the expressionof NF-κB p65 mRNA and nuclear p65 were determined by the real-time fluorescence quantitative PCR(RT-qPCR)and Western blot. Results showed that 5-40 μmol/L corynoline reduced the expression level of TLR4 and TLR2, and inhibited the phosphorylation level of IκBα and the phosphorylation and nuclear translocation of p65 at gene and protein levelin a dose-dependent manner in LPS-induced RAW264. 7 cells. This study indicated the protective effect of corynoline on LPS-induced RAW264. 7 macrophages may be related with the inhibition of TLRs/NF-κB inflammatory signaling pathway.