Function and mechanism of ligustilide on apoptosis induced by interleukin-1β of cartilage cells

Abstract

Objective To investigate the effect of different concentrations of the Z-ligustilide (LIG) on proliferation and apoptosis induced by interleukin (IL)-1β of cartilage cells in vitro. Methods Healthy specific pathogen free (SPF) Sprague Dawley rats aged 2 weeks were selected and chondrocytes from knee joints were isolated, cultured and identified. The final concentrations of 15, 25, 50, 75 μmol/L ligustilide were added to the second-generation chondrocyte culture plate, and cell proliferation was detected by cell counting kit-8 (CCK-8). Ligustilide was added into chondrocytes induced by IL-1β of appropriate concentration and the cells in the control group. The effect of different concentrations of ligustilide on the apoptosis of chondrocytes induced by IL-1β was detected by flow cytometry. The effect of ligustilide on nuclear morphological changes of apoptotic chondrocytes was observed by Hoechst34580 nuclear staining; Western blotting was used to detect the expression of cysteinyl aspartate-specific protease (Caspase)-3, Caspase-9, B cell lymphoma/leukemia-2 (bcl-2), bcl-2 associated X protein (bax) and inducible nitric oxide synthase (iNOS) in chondrocytes. Results The results of CCK-8 showed that ligustilide had no significant effect on the proliferation of chondrocytes in the range of 15-70 μmol/L (P>0.05). Flow cytometry results showed that ligustilide at a final concentration of 25-75 μmol/L could reduce the apoptosis of chondrocytes induced by IL-1β [rate of apoptosis: (20.12±2.07)%, (13.79±3.19)% and (7.86±2.14)%, t=17.260, 13.140, 6.350, respectively, P<0.05]. The results of Hoechst34580 showed that ligustilide can reduce the IL-1β-induced chondrocyte apoptosis. Western blotting analysis showed that ligustilide could decrease the expression of Caspase-3, Caspase-9, bax and iNOS and increase the bcl-2/bax ratio (P<0.05). Conclusion Ligustilide can inhibit the apoptosis of chondrocytes induced by IL-1β in a dose-dependent manner. Key words: Apoptosis; Cartilage cells; Ligustilide; Inhibit apoptosis