Gardenoside ameliorates inflammation and inhibits ECM degradation in IL-1β-treated rat chondrocytes via suppressing NF-κB signaling pathways

Osteoarthritis (OA) places a significant burden on society and finance, and there is presently no effective treatment beside late replacement surgery and symptomatic relief. The therapy of OA requires additional research. Gardenoside is a naturally compound extracted from Gardenia jasminoides Ellis, which has a variety of anti-inflammatory effects. However, few studies have been conducted to determine the role of gardenoside in OA. This study aimed to explore whether gardenoside has effect in OA treatment. Rat primary chondrocytes were treated with IL-1β to simulate inflammatory environmental conditions and OA in vitro. We examined the effects of gardenoside at concentrations ranging from 0 to 200 μM on the viability of rat chondrocytes and selected 10 μM for further study. Via in vitro experiments, our study found that gardenoside lowers the gene expression of COX-2, iNOS, IL-6, and reduced the ROS production of chondrocytes induced by IL-1β. Moreover, it effectively alleviates ECM degradation caused by IL-1β and promotes the ECM synthesis in chondrocytes by upregulating collagen-II and the ACAN expression, downregulating the expression of MMP-3, MMP-13, and ADAMTS-5 expression. Further, our study showed that gardenoside inhibits NF-κB signaling pathway activated by IL-1β in chondrocytes. We established an OA rat model by anterior cruciate ligament transection (ACLT). The animals were then periodically injected with gardenoside into the knee articular cavity. In vivo study suggested that gardenoside attenuates OA progression in rats. As a whole, in vitro and in vivo results highlight gardenoside is a promising OA treatment agent.