Objective: To observe the effect of curcumin on the expression levels of nuclear factor κB-p65 (NF-κB-p65) and tumour necrosis factor α (TNF-α) in the nucleus pulposus in rats with lumbar intervertebral disc degeneration. And to investigate of the mechanism underlying the role of curcumin in decelerating the process of lumbar intervertebral disc degeneration.
Materials and methods: The model of lumbar intervertebral disc degeneration was established in Sprague-Dawley (SD) rats followed by a curcumin treatment. The ultra-microstructure histomorphological variations in the lumbar intervertebral disc of SD rats were evaluated. The protein and gene expression levels of NF-κB-p65 and TNF-α in the lumbar intervertebral disc were measured.
Results: Magnetic resonance imaging (MRI) and histomorphology confirmed the establishment of a successful lumbar intervertebral disc degeneration model. The results from the MRI and the ultra-microstructures revealed a significant improvement in lumbar intervertebral disc degeneration in the curcumin-treated groups (low dose and high dose). No significant change was observed in the solvent control group treated with dimethyl sulfoxide (DMSO) alone. Based on the results of Western blot analysis and real-time PCR, the curcumin treatment (low dose and high dose) significantly reduced the expression levels of NF-κB-p65 and TNF-α in the lumbar intervertebral disc tissue compared with the groups without curcumin treatment and with the DMSO treatment alone. No significant difference, however, was observed between the low-dose and high-dose curcumin treatment groups.
Conclusions: Curcumin may inhibit the activation of NF-κB by inhibiting the translocation of NF-κB-p65 and reducing the release of inflammatory factors which, thereby, decelerates the process of lumbar intervertebral disc degeneration.