Xiongshao Zhitong granules alleviate nitroglycerin-induced migraine by regulating the TRPV1-mediated NLRP3 inflammatory pathway in rats

BACKGROUND: Migraine is a prevalent neurological disorder accompanied by a considerable economic burden. Xiongshao Zhitong granules (XSZT) have anti-inflammatory and analgesic functions in the clinic and are used for migraine therapy. However, the mechanisms by which XSZT treats migraine remain unclear. PURPOSE: To discover the underlying mechanism and active ingredients of XSZT in the treatment of migraine. METHODS: The nitroglycerin (NTG)-induced chronic migraine (CM) model was established and used to detect the therapeutic effect of XSZT on migraine. To elucidate the mechanism, we detected transient receptor potential vanilloid 1 (TRPV1) -mediated NOD-like receptor protein 3 (NLRP3) inflammasome activation in the CM rat model and the LPS-induced inflammatory BV-2 cell model using Western blotting, immunofluorescence and ELISA techniques. The potentially active ingredients of XSZT were determined by UHPLC-LTQ-Orbitrap MS, molecular docking, and surface plasmon resonance. RESULTS: Our findings revealed that XSZT reduced the number of head scratching, increased the periorbital pain threshold and shortened the time spent in the dark box, decreased c-Fos expression in the CM rat model, suggesting an analgesic effect of XSZT on migraine. XSZT inhibited neurogenic inflammation, including downregulating CGRP, TNF-α, IL-1β and IL-18 levels and decreasing the degranulation rate of mast cells. Additionally, XSZT suppressed the expression and activation of TRPV1 and the NLRP3 inflammasome in the trigeminal nucleus caudalis. In vitro experiments confirmed that activated TRPV1 increased the level of the NLRP3 inflammasome by increasing intracellular calcium levels. Galloylpaeoniflorin, isogastrin, ellagic acid and salvianolic acid A interacted with TRPV1 and inhibited IL-1β secretion. CONCLUSION: XSZT plays a therapeutic role in migraine through regulating TRPV1-mediated NLRP3 inflammatory activation and galloylpaeoniflorin, isogastrin, ellagic acid and salvianolic acid A might be the active ingredients of XSZT, which provides an experimental basis for the clinical treatment of migraine.