Wutou decoction ameliorates experimental rheumatoid arthritis via regulating NF-kB and Nrf2: Integrating efficacy-oriented compatibility of traditional Chinese medicine

Thousands of years of clinical application of Wutou decoction (WTD) support its reliable efficacy and safety in treating rheumatoid arthritis (RA). However, the underlying molecular mechanism remains unclear, and the synergistic involvement of assistant herbs in WTD in enhancing the sovereign herb in treating RA is unknown. This study aimed to investigate the efficacy-oriented compatibility of five herbs in WTD and the underlying mechanisms. The anti-arthritic effects of WTD and the compatibilities of the five herbs in WTD were studied in vivo with adjuvant-induced arthritis (AIA) rat model and in vitro with LPS-induced RAW264.7 macrophage. Network pharmacology analysis was conducted to identify the dominant pathways involved in the anti-arthritis mechanisms of WTD and how the five herbs work synergistically. The results were further verified by in vivo and in vitro experiments. Our data revealed that the five herbs in WTD exert synergistic anti-arthritic effects on RA. Moreover, Radix Aconite (AC) is the principal anti-inflammatory component in WTD according to the extent of therapeutic effects exerted on the AIA rats. In vivo and in vitro experiments demonstrated that WTD inhibited NF-κB phosphorylation and simultaneously increased the expression of Nrf2, which were the major pathways identified by the network pharmacology analysis. The major assistant component, Herba Ephedrae (EP), evidently inhibited NF-κB mediated inflammatory response. The other assistant component, Radix Astragali (AS), considerably enhanced the expression of Nrf2 when used alone or in combination with AC. These combinations improved the anti-arthritis effects on the AIA rats better than that of AC alone. Nevertheless, WTD always achieved the best effects than any combinations both in vivo and in vitro. The ministerial herbs EP and AS intensify the anti-arthritic effects of AC by regulating the NF-κB-mediated inflammatory pathway and the Nrf2-mediated anti-oxidation pathway which are the major pathways of WTD for alleviating the symptoms of RA.