Chinese herb pair Paeoniae Radix Alba and Atractylodis Macrocephalae Rhizoma suppresses LPS-induced inflammatory response through inhibiting MAPK and NF-κB pathway

Abstract

Abstract Background The combination of Radix Paeoniae Alba (RPA) and Rhizoma Atractylodis Macrocephalae (RAM) has long been used as a classic herb pair for the treatment of gynecologic and gastrointestinal diseases, but the underlying mechanisms of the herb pair remain unknown. This study aims to explore the anti-inflammatory potentials of RPA–RAM herb pair and to elucidate the underlying mechanisms. Methods The bioactive parts of RPA–RAM were extracted and screened through the inhibitory effects against nitric oxide (NO) production. The effects of optimized RPA–RAM extracts (OPAE) on inflammation-associated mediators were investigated by Western blotting, real-time quantitative PCR (RT-qPCR), Enzyme-linked immunosorbent (ELISA) and immunofluorescence staining. Results OPAE potently suppressed the productions of NO, TNF-α, IL-6 and MCP-1 in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages, concentration-dependently inhibited protein level of inducible nitric oxide synthase (iNOS), dramatically downregulated mRNA expression of iNOS, TNF-α, IL-6 and MCP-1. In addition, OPAE significantly prevented phosphorylation and degradation of inhibitory kappa Bα (IκBα) and subsequently restrained the nuclear translocation of NF-κB p65. Pretreatment with OPAE also attenuated the LPS-induced phosphorylation of ERK, JNK and p38. Conclusions Our findings demonstrated that OPAE suppressed inflammatory responses in LPS-stimulated RAW 264.7 macrophages by decreasing critical molecules involved in MAPK and NF-κB pathway, suggesting that the herb pair could be a promising therapeutic candidate for inflammation-related diseases.

Keywords

• Radix Paeoniae Alba
• Rhizoma Atractylodis Macrocephalae
• Herb pair
• Inflammatory