Isorhamnetin inhibits IL‑1β‑induced expression of inflammatory mediators in human chondrocytes.

Isorhamnetin (ISH) is a flavonoid primarily obtained from the fruit of Hippophae rhamnoides L., which possesses anti‑inflammatory properties. However, the effect of ISH on the expression of inflammatory mediators in response to interleukin (IL)‑1β stimulation has not been elucidated. The present study investigated the effects of ISH on the expression of inflammatory mediators in human chondrocytes, induced by IL‑1β. The results of the present study demonstrated that pretreatment with ISH inhibited the expression of stromelysin‑1 and collagenase 3 in chondrocytes, induced by IL‑1β. Pretreatment with ISH inhibited the IL‑1β‑stimulated synthesis of NO and prostaglandin E2 induced by IL‑1β, in addition to the expression of inducible nitric oxide synthase and prostaglandin G/H synthase 2 in chondrocytes. Additionally, ISH inhibited the expression of nuclear factor (NF)‑κB and transcription factor p65, and the degradation of NF‑κB inhibitor α induced by IL‑1β in chondrocytes. In conclusion, the results of the present study indicated that ISH exhibited anti‑inflammatory and chondroprotective effects in IL‑1β‑stimulated chondrocytes. The results of the present study suggest that ISH may be a potential agent in the future treatment of osteoarthritis.