Gigantol Alleviates IL-1β-Induced Inflammation and Catabolism in Mouse Osteoarthritis via PI3K/Akt/NF-κB Pathways In Vivo and In Vitro

Abstract

Osteoarthritis (OA), a prevalent disabling disease, is characterized by irreversible cartilage degradation and persistent inflammation. The etiology as well as pathogenesis of OA are not completely unclear and need further investigation. Gigantol, is a bibenzyl derivative extracted from Dendrobium plants and has been found exhibit multiple effects such as anti-inflammatory effects. Nevertheless, the biological function of gigantol on osteoarthritis (OA) is still uncertain. This study aimed at examining the anti-inflammatory effects and latent mechanisms of gigantol in IL-1β-mediated OA progression. In vitro, we identified that gigantol treatment suppressed tumor necrosis factor-alpha (TNF-α), nitric oxide (NO), cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2), inducible nitric oxide synthase (iNOS) and interleukin-6 (IL-6) in interleukin-1 beta (IL-1β) mediated mouse OA chondrocytes. Gigantol was also shown to dose dependently downregulate the metalloproteinase 13 (MMP13) as well as thrombospondin motifs 5 (ADAMTS5) levels. Moreover, IL-1β-mediated AKT and PI3K phosphorylation as well as NF-κB activation were inhibited by gigantol. Meanwhile, in vivo, we detected that gigantol treatment inhibited degradation of the cartilage degradation and lowered the Osteoarthritis Research Society International scores (OARSI) in OA mouse. Therefore, gigantol is a promising therapeutic option for OA.