Abstract: OBJECTIVE To investigate the protective effect of diacerein on interleukin-1β-induced rat chondrocytes injury. METHODS Chondrocytes were isolated from the knee joints of Sprague-Dawley rats by enzymatic digestion. Rat chondrocytes were co-treated with IL-1β(10 ng·mL^-1) and diacerein(1, 10, 100 μmol·L^-1) for 48 h. The viability of chondrocytes was detected by MTT assay. The level of NO was assayed by Griess method. Inflammation related protein cyclooxygenase-2(COX-2) was assayed by Western blot. Finally, the expression of nuclear factor kappa B(NF-κB) p65 and p65 phosphorylation were detected by Western blot. RESULTS MTT assay demonstrated diacerein(1, 10, 100 μmol·L^-1) could protect IL-1β-induced chondrocytes viability. Diacerein also inhibited the increasing levels of NO in IL-1β-induced chondrocytes. Western blot assays presented diacerein could suppress IL-1β-induced increasing levels of COX-2. What’s more, diacerein inhibited NF-κB p65 phosphorylation induced by IL-1β in rat chondrocytes. CONCLUSION Diacerein exertes anti- inflammation in IL-1β-induced rat chondrocytes, which might be related to NF-κB signal pathway.