Anti-inflammatory potential of Patrineolignan B isolated from Patrinia scabra in LPS-stimulated macrophages via inhibition of NF-κB, AP-1, and JAK/STAT pathways

Patrineolignan B (PB), a lignan compound isolated from the radix and rhizomes of Patrinia scabra, was previously reported to possess a strong tumor-specific cytotoxic activity and beneficial effects on nitric oxide (NO) levels in macrophages induced by lipopolysaccharide (LPS). In this study, we assessed the effects of PB on LPS-induced inflammation in RAW 264.7 cells and clarified its molecular mechanisms. PB reversed LPS-induced increase in NO levels and prostaglandin E 2 (PGE 2 ) production, as well as inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) protein and mRNA levels in macrophages. Besides, PB prevented the secretion of pro-inflammatory cytokines, such as tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-6 in a concentration-dependent manner. The regulatory effects of PB on LPS-induced inflammatory mediators and overproduction of pro-inflammatory cytokines were shown to depend partly on the suppression of nuclear factor kappa B (NF-κB)-mediated transcription and AP-1 activation regulated by a c-Jun amino-terminal kinase (JNK) and extracellular signal-regulated kinases (ERK). Its anti-inflammatory activity was also mediated by regulating the phosphorylation of Janus kinase (JAK)/signal transducers and activators of transcription 1/3 (STAT1/3) signaling pathway. Taken together, our results suggest that PB exhibits anti-inflammatory potency through interfering with the NF-κB, AP-1, and JAK/STAT signaling pathway in LPS-stimulated macrophages.