Gastrodin Alleviates Lumbar Intervertebral Disc Degeneration by Suppressing the NF-κB and MAPK Pathways

Intervertebral disc degeneration (IDD) is the main pathological factor resulting in low back pain (LBP), the leading cause of disability globally. Inflammatory response and extracellular matrix (ECM) degradation are critical pathological features in the development of IDD. Gastrodin (GAS), a phenol compound isolated from Gastrodia elata Blume, plays an anti-inflammatory role in experimental models of multiple human diseases. Our study aimed to elucidate whether GAS alleviates TNF-α-induced inflammation in nucleus pulposus (NP) cells and IDD in vivo. The cytotoxicity of GAS was assessed by CCK-8 assay. Rat primary NP cells were stimulated with TNF-α to induce inflammatory response. The expression of proinflammatory cytokines, catabolic genes, and anabolic genes was detected by RT-qPCR, western blotting, and immunofluorescence staining. NF-κB and MAPK pathway activation was determined through western blotting and immunofluorescence staining. The IDD rat model was established by using percutaneous needle puncture. The therapeutic effects of GAS were confirmed by histology analysis. We found that TNF-α stimulation enhanced proinflammatory cytokine (COX2, iNOS, IL-6, and IL-1β) expression in NP cells, which was reversed by GAS treatment. GAS offset TNF-α-induced upregulation in catabolic gene (MMP3, MMP9, and MMP13) expression and downregulation in anabolic gene (Collagen II, SOX9, and Aggrecan) expression. The loss of ECM in TNF-α-treated NP cells was mitigated by GAS treatment. Mechanically, GAS abolished TNF-α-induced increase in p-IKKα, p-IKKβ, p-IκBα, p-p65, p-ERK, p-p38, and p-JNK protein levels in NP cells. In puncture-induced IDD rat models, GAS administration improved intervertebral disc (IVD) structure, increased Collagen II expression, and reduced the levels of proinflammatory factors in IVDs. Overall, GAS alleviates the inflammation and ECM degradation in NP cells via inhibiting NF-κB and MAPK pathway activation and alleviates IDD in vivo, which may be a novel treatment strategy for IDD.