Duchesnea indica (Andr.) Focke extracts exerted anti-inflammatory effect via inhibiting MAPK/ERK pathway in LPS-stimulated RAW264.7 cells.

Duchesnea indica (Andr.) Focke (DIF), a medicinal plant from the Rosaceae family, possesses therapeutic properties such as heat-clearing and detoxification, dispersion of stasis detumescence, blood-cooling, and hemostatic effect. The latest research unveiled a diverse array of pharmacologically active compounds from DIF, showcasing a broad spectrum of pharmacological effects. However, there was limited attention given to the comprehensive investigation of its high molecular weight compounds, particularly polysaccharides. In this study, DIF extracts were prepared by water-extraction and alcohol-precipitation method and the pharmacological effect was detected. The results demonstrated that the total polysaccharide content, reducing sugar content, total flavonoid content, and total polyphenol content in DIF extracts were 32.62 ± 0.91 %, 13.41 ± 0.18 %, 1.07 ± 0.07 %, and 12.16 ± 0.27 %, respectively. Although the total antioxidant activity of DIF extracts were significantly low than that of the vitamin C group, its ability to scavenge ABTS, DPPH, and superoxide anion radicals was similar to that of the vitamin C group. Furthermore, DIF extracts demonstrated significant inhibition on NO and MDA levels while simultaneously enhancing SOD activity in LPS-stimulated RAW264.7 cells. Finally, DIF extracts significantly reduced the mRNA level of pro-inflammation cytokines interleukin (IL)-6, IL-1β, inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and tumor necrosis factor (TNF)-α, and directly inhibited the phosphorylation level of extracellular regulated kinase and mitogen-activated protein kinase (ERK-MAPK) pathway. Taken together, these results indicated that DIF extracts exhibited an anti-inflammatory and antioxidant effect in LPS-induced RAW264.7 mouse macrophages by directly inhibiting ERK-MAPK signaling pathway. Based on these findings, DIF extracts provided new insights into the treatment and prevention of diseases related to oxidative stress and inflammation.