Effects of Zhengtian Pills on Migraine Headache in Rats via Transient Receptor Potential Vanilloid 1

Abstract Objective To investigate the effects and molecular mechanism of Zhengtian Pills (ZTP) on migraine headache. Methods All rats were randomly divided into control, positive control, migraine model, low- and high-dose ZTP groups, and glyceryl trinitrate was injected to induce migraine headache. The time of ears turning red, frequency of scratching head, climbing the cage, and head-twitching were used to evaluate rat behaviors. After 10 d administration of ZTP, the expression levels of transient receptor potential vanilloid 1 (TRPV1) both in cortex and hippocampus were determined by Western blotting. Results After 2 min of glyceryl trinitrate injection, rats showed headache phenomena that parallels the clinical symptoms of migraine, which peaked in 30 min, and lasted for 60 min. Frequency of head-twitching and numbers of scratching head in glyceryl trinitrate (GTN) group were significantly increased. In contrast, after ZTP (1.08 g/kg, ig) treatment, the numbers of scratching head with fore-limb, hind-limb and the frequency of head-twitching were significantly decreased. Flunarizine (FLU) and low-dose ZTP (0.54 g/kg) also showed a trend to decrease the numbers of scratching head and head-twitching frequency, but no significant difference. Besides, ZTP significantly decreased the up-regulated TRPV1 protein expression level both in cortex and hippocampus. Conclusion The present study shows that ZTP could significantly improve the migraine symptoms of headache in rats and TRPV1 might be one of the important molecular mechanisms. This is the first report about the effect of ZTP on TRPV1 protein expression level both in cortex and hippocampus of rats.