The anti-inflammatory effects of jiangrines from Jiangella alba through inhibition of p38 and NF-κB signaling pathways

Three pyrrol-2-aldehyde derivatives, including one new compound, jiangrine G (JG), two known compounds, jiangrine A (JA), and pyrrolezanthine (PZ), were isolated from the fermentation broth of Jiangella alba associated with a traditional Chinese medicinal plant Maytenus austroyunnanensis. The structure of jiangrine G was elucidated by a detailed spectroscopic data analysis including data from CD spectra. The anti-inflammatory activities assay demonstrated that JG and JA suppressed the production of pro-inflammatory cytokines including NO, IL-1 beta, and IL-6 as well as inhibited the expression of iNOS in LPS-induced RAW 264.7 cells in a dose-dependent manner. While high concentration of PZ dramatically suppressed the protein expression of TNF-alpha, but stimulated the release of IL-1 beta and IL-6. Western blot results revealed that JG, JA, and PZ modulated the expression of pro-inflammatory cytokines via MAPK p38 and NF-kappa B signaling pathways. For the unique structure of PZ, difference from JG and JA, the signaling pathway involved in mediating its effects on regulating the synthesis of IL-1 beta and IL-6 are probably more complicated than that of JG and JA.