The neuroprotective mechanism of puerarin treatment of acute spinal cord injury in rats

Puerarin extracted from radix puraeriae is shown to exert a variety of pharmacological effects including neuroprotective properties. However, its mechanisms of action are needed to further explore. The study was designed to investigate the mechanism of puerarin treatment of acute spinal cord ischemia-reperfusion injury (SCI/RI) in rats. SCI/RI was conducted in male Sprague-Dawley rats, and 50 mg/kg of puerarin was injected intraperitoneally at 1, 2, 4 and 6 h after reperfusion, followed by the same dose of injection every 24 h for 2 days. Glutamate level, metabotropic glutamate receptors (mGluR) mRNA expression, and apoptosis indices were examined. Neurologic function was assessed at 48 h of reperfusion. SCI/RI caused extensive motor deficit associated with an elevation of glutamate level and mGluRs-1 mRNA expression, while puerarin administration improved motor deficit, and decreased glutamate level and inhibited mGluRs-1 mRNA expression. The present study demonstrated that administration of puerarin reduced the spinal ischemia/reperfusion injury, and suggested that the neuroprotective mechanism of puerarin involved a decrease in glutamate release and mGluRs-1 mRNA expression.