Effectiveness of acupuncture in migraine rats: A systematic review

OBJECTIVE: To systematically evaluate the effectiveness and potential underlying mechanisms of acupuncture in the treatment of experimental model of migraine in rats. METHODS: Nine electronic databases, including CNKI (China National Knowledge Infrastructure), WanFang, VIP (Chinese Scientific Journals Database), Sinomed, PubMed, Cochrane Library, Web of Science and EBSCO, were searched for randomized experimental studies on migraine in rats involving acupuncture intervention. The search period ranged from inception to June 2022. The methodological quality was assessed using the SYRCLE’s risk of bias tool for animal studies. Data were analyzed using the Revman 5.3 software. RESULTS: A total of 13 studies were included in this analysis. Findings from the available experimental studies documented that acupuncture significantly reduced behavior scores of rats with migraine (MD = -15.01, 95%CI = [-18.01, -12.01], P<0.00001) and downregulated the expression of calcitonin gene-related peptide (CGRP) (MD = -16.14, 95%CI = [-21.45, -10.83], P<0.00001), substance P (SP) (MD = -11.47, 95%CI = [-15.97, -6.98], P<0.00001) and nitric oxide (NO) (MD = -3.02, 95%CI = [-3.79, -2.26], P<0.00001) in serum, and stimulatory G protein (Gsa) (MD = -62.90, 95%CI = [-69.88, -55.92], P<0.00001) in brainstem. Acupuncture also significantly increased the content of inhibitory G protein (Gia) (MD = 24.01, 95%CI = [20.10, 27.92], P<0.00001) in brainstem and 50% paw withdrawal threshold (50%PWT) (MD = 1.96, 95%CI = [1.15, 2.77], P<0.00001). CONCLUSION: Acupuncture can effectively improve the behavioral performance of rates with migraine, and its mechanism of action might involve the inhibition of meningeal vasodilation and inflammatory factors, and the reduction of neurogenic inflammation.