Plastrum Testudinis Extract Ameliorates Intervertebral Disc Degeneration by Suppressing NF-κB Mediated Senescence and Inflammation.

Abstract

Intervertebral disc degeneration (IVDD) is a major cause of chronic low-back pain (LBP). The inflammatory environment and senescence of nucleus pulposus cells (NPCs) within the intervertebral disc (IVD) are critical processes in IVDD. Plastrum testudinis extract (PTE) has been proven to have anti-inflammatory qualities; however it is unknown whether it can impact the progression of IVDD and NPC senescence. We investigated the effects of PTE on NPC senescence induced by tert-butyl hydrogen peroxide (TBHP) in vitro. Cell viability, senescence-associated secretory phenotype (SASP), inflammatory factors, and extracellular matrix (ECM) were assessed. The NF-κB pathway was activated using lipopolysaccharide (LPS) to explore underlying mechanisms. In vivo studies used a senile mouse with IVDD, evaluating disc structure and inflammatory factors after PTE treatment. TBHP stimulation rapidly induced NPC senescence, increased inflammatory factors, and disrupted ECM anabolic balance; these effects were partially alleviated by PTE treatment. PTE inhibited NF-κB pathway activation and prevented p65 nuclear translocation. In senile mice, PTE treatment partially preserved IVD structural integrity. Immunohistochemistry showed PTE inhibited IL-1β expression, while immunofluorescence demonstrated increased aggrecan expression following PTE treatment. PTE delays IVDD progression through anti-inflammatory effects, specifically by inhibiting NF-κB pathway activation and reducing inflammatory factor expression. These findings suggest PTE could be a promising therapeutic agent for IVDD treatment.