Protective Effect of Polygonatum sibiricum Polysaccharides on Apoptosis, Inflammation, and Oxidative Stress in Nucleus Pulposus Cells of Rats with the Degeneration of the Intervertebral Disc

Objective. Polygonatum sibiricum polysaccharide (PSP) has antioxidant activity, immune enhancement, and other biological properties. However, the effect of PSP on intervertebral disc degeneration has not been reported. In this study, we mainly investigated the effect of PSP on the apoptosis, inflammation, and oxidative stress of nucleus pulposus cells (NPCs) during the process of intervertebral disc degeneration. Methods. A rat NPC model induced by H2O2 was constructed. The CCK8 method was used to measure the effects of PSP on the apoptosis of rat NPCs induced by H2O2. The effects on the activity of SOD and content of MDA were also determined. The rat model of intervertebral disc degeneration was treated with PSP for 1 month, and the mRNA expression levels of IL-1 beta, COX2, iNOS, Col2 alpha 1, Col10 alpha 1, and MMP3 were measured by qPCR in the tissue of intervertebral disc. NPCs from the degenerated intervertebral discs were separated, and the cell viability was measured by the CCK8 method. The contents of SOD and MDA in NPCs were determined as well. Results. PSP significantly reduced the apoptosis of NPCs induced by H2O2, significantly increased the SOD content, and decreased the content of MDA in H2O2-induced NPCs. The expression level of IL-1 beta, COX2, and iNOS in the rat model with intervertebral disc degeneration was significantly downregulated after 1 month of PSP treatment. PSP treatment increased the expression of Col2 alpha 1 type and significantly decreased the expression of Col10 alpha 1 type collagen and MMP3 in rats with disc degeneration. PSP treatment significantly reduced NPC apoptosis and increased its SOD content and reduced MDA content, which is consistent with the results from cell-level experiments. Conclusion. PSP can effectively reduce the apoptosis, inflammation, and oxidative stress of H2O2-induced NPCs in rats with intervertebral disc degeneration and mitigate the progression of intervertebral disc degeneration, which has the potential to be developed as new drugs for the treatment of intervertebral disc degeneration.