Figure 3.

Melatonin (MT) increased chondrocyte viability and up-regulated sirtuin 2-related enzyme 1 (SIRT1) expression in interleukin 1-beta (IL-1β)-treated chondrocytes. (A) The effect of MT on the activity of rat chondrocytes for 24 and 48 h. (B) The transcription level of SIRT1 messenger RNA (mRNA) was detected by real-time PCR (qRT-PCR). (C,D) Western blot (WB) to detect the expression level of SIRT1 protein. Gray values were analyzed with ImageJ. All values represent mean ± standard deviation (SD) (n = 3), * p < 0.05, ** p < 0.01 (compared with the model group).