Achyranthoside D attenuates chondrocyte loss and inflammation in osteoarthritis via targeted regulation of Wnt3a

•Achyranthoside D is effective in relieving ACLT-MMx-induced osteoarthritis in rats.•Achyranthoside D inhibits NLRP3 inflammasome-triggered inflammation in rats.•Achyranthoside D attenuates IL-1β-induced chondrocyte loss in vitro.•Achyranthoside D inhibits NLRP3 inflammasome-triggered inflammation in vitro.•Achyranthoside D exerts anti-osteoarthritis effects via targeting Wnt3a. Achyranthes bidentata Blume (A. bidentata) is a common Chinese herb used to treat osteoarthritis (OA). Achyranthoside D (Ach-D) is a glucuronide saponin isolated from A. bidentata. To assess the mechanisms of action of Ach-D and its effects on OA. The effects of Ach-D were evaluated in rats underwent anterior cruciate ligament transection (ACLT) with medial meniscectomy (MMx) and in interleukin (IL)-1β-induced chondrocytes. Histological changes in rat cartilage tissues were detected using Safranin O-Fast green and haematoxylin-eosin staining. Immunohistochemical staining, qRT-PCR, ELISA, immunoblotting, and immunofluorescence were conducted to examine cartilage degeneration-related and inflammation-related factor expression. CCK-8, LDH assay, and EdU staining were performed to detect chondrocyte death. Ach-D dose-dependently reduced the Osteoarthritis Research Society International (OARSI) scores, alleviated cartilage injury, and decreased the serum concentrations of CTX-II and COMP in ACLT-MMx models. Ach-D increased the expression levels of collagen II and aggrecan and decreased the levels of cartilage degeneration-related proteins, ADAMTS-5, MMP13, and MMP3, in rat cartilage tissues. Additionally, nod-like receptor protein 3 (NLRP3)-related inflammation was reduced by Ach-D, as shown by the significantly inhibited expression levels of NLRP3, ASC, GSDMD, IL-6, TNF-α, IL-1β, and IL-18 in rat cartilage tissues. In primary rat chondrocytes, Ach-D protected against IL-1β-induced viability loss and LDH release. Wnt3a is the target protein of Ach-D. Mechanistically, Ach-D alleviated OA by inhibiting Wnt signalling. ACH-D may reduce inflammation and cartilage degeneration by inhibiting the Wnt signalling pathway, thereby reducing OA. [Display omitted]