Anti-Apoptosis and Anti-Inflammatory Effect of Tetramethylpyrazine on Improving Motor Function of Rats with Spinal Cord Injury

The main objective of this study is to explore the effects of tetramethylpyrazine on functional recovery, inflammation and apoptosis after spinal cord injury in rats. Four experimental groups of rats were used (n=15), which included sham+vehicle group where only laminectomy was performed, sham+tetramethylpyrazine group where only laminectomy was performed, spinal cord injury+vehicle group where spinal cord injury was induced through clip compression technique and spinal cord injury+tetramethylpyrazine group where spinal cord injury was induced. The control group was given the same dose of normal saline and the four groups were intervened under the same conditions, tetramethylpyrazine was used intraperitoneally to observe the possible therapeutic effects compared to controls. Locomotor function in experimental rats improved after 20 d of treatment with tetramethylpyrazine evident by Basso Mouse scaled score performed by blind observers and terminal deoxynucleotidyl transferase-deoxyuridine triphosphate nick end labeling assay also showed antiapoptotic effect. It was observed that nuclear factor kappa B subunit p65 levels and phosphorylated nuclear factor kappa B subunit p65 levels were significantly reduced after treatment with tetramethylpyrazine. Proinflammatory cytokines, tumor necrosis factor alpha and interleukin-1 beta levels were also reduced along with myeloperoxidase activity in treated rats. It was observed that tetramethylpyrazine (20 mg/kg, body weight dose) restored locomotor function along with antiapoptotic effects and it is beneficial to improve the lower limb activity of rats, reduces infiltration of neutrophils and attenuation of other inflammatory markers that helps in the reduction of inflammation which is an important part of secondary phase of spinal cord injury pathology.