Tetrahydropalmatine reduces cell death and improves functional recovery after traumatic spinal cord injury in rats

Purpose: To investigate the effectiveness of tetrahydropalmatine (THP) in the treatment of spinal cord injury (SCI) in rats. Methods: Adult Sprague Dawley rats were divided into 3 groups: normal control group, SCI group, and SCI group treated with THP (100 mg kg-1). The effect of THP on spinal cord water content, levels of inflammatory mediators, oxidative stress and apoptosis were determined. Locomotor activity in rats was measured using Basso, Beattie and Bresnahan (BBB) scores. Various oxidative stress markers as well as cytokine levels (NF-kappa B, IL-6, IL-1 beta and TNF-alpha were determined. Apoptotic index was measured using TUNEL assay. Results: After 72 h of treatment with THP, BBB scores in SCI group of rats significantly increased from 4.19 +/- 0.41 to 8.89 +/- 0.47 (p < 0.05). Tunel assay revealed a higher apoptotic index (42.50 +/- 3.19) in the tissues of SCI rats than in SCI rats treated with THP (31.48 +/- 1.19, p < 0.01). Expressions of inflammatory cytokines were significantly upregulated in SCI rats. However, THP administration resulted in significant downregulation of the expressions (p < 0.01). Conclusion: These results indicate that THP attenuates traumatic SCI in rats via modulation of the levels of anti-inflammatory mediators. Thus, THP has a promising potential for the management of SCI.