Dendropanax proteus root and its major bio-phytochemicals alleviate rheumatoid arthritis by inhibiting TLR4/CLEC1B/PI3K/Akt/NF-κB pathways: proteomics, metabolomics, collagen-induced arthritis rats, MH7A cells, molecular docking, and molecular dynamic simulation

Ethnopharmacological relevance: Dendropanax proteus (Champ.) Benth. root (DPR) is a traditional anti-rheumatoid arthritis (RA) plant in China. However, its bio-phytochemicals, effect, and mechanism against RA remain unclear.

Aim of the study: To explore the major bio-phytochemicals, therapeutical effect, and underlying mechanism of DPR against RA.

Materials and methods: The therapeutical effect of DPR was measured in both collagen-induced arthritis (CIA) rats and TNF-α-induced MH7A cells. Proteomics, metabolomics, and cell model were carried out to uncover the underlying mechanism of DPR. The major bio-phytochemicals in DPR were identified and isolated, and their anti-RA effects and mechanisms were evaluated using MH7A cells, molecular docking, and molecular dynamic simulation.

Results: DPR significantly alleviated paw swelling, reduced arthritis scores, and decreased serum levels of TNF-α, IL-1β, IL-17, IFN-γ, CRP, and RF in CIA rats. DPR also inhibited inflammation and repaired cartilage damage in the ankle joint, as evidenced by hematoxylin and eosin staining, safranin O-fast green staining, Alcian blue staining, and tartrate-resistant Acid Phosphatase staining. Proteomic and metabolomic analyses indicated that DPR's anti-RA mechanism is associated with the inhibition of TLR4/CLEC1B/PI3K/Akt/NF-κB pathways, as validated by Western blotting experiments. Syringin and chlorogenic acid, identified as two major phytochemicals in DPR, possess strong anti-RA effects in TNF-α-induced MH7A cells and good binding abilities with TLR4, Rap1, CLEC1B, PI3K, Akt, and p65 proteins.

Conclusions: DPR alleviates RA by inhibiting TLR4/CLEC1B/PI3K/Akt/NF-κB pathways, with syringin and chlorogenic acid as its major bio-phytochemicals. This study provides scientific evidence supporting the clinical use of DPR and offers potential lead compounds for the development of anti-RA agents.

Dendropanax proteus root; Rheumatoid arthritis; Syringin and chlorogenic acid; TLR4/CLEC1B/PI3K/Akt/NF-κB pathways.