Cerebrolysin attenuates hyperalgesia, photophobia, and neuroinflammation in a nitroglycerin-induced migraine model in rats

•Systemic cerebrolysin (CBL) attenuates nitroglycerin (NTG)-induced mechanical and thermal hyperalgesia.•CBL reverses migraine-associated photophobic behaviors.•CBL down-regulates migraine-related neuropeptides including CGRP and PACAP levels.•CBL reduces pro-inflammatory cytokines such TNF-α and IL-1β levels in the serum. Chronic migraine dramatically affects the quality of life in the migraineurs. This study examined the effect of chronic cerebrolysin (CBL) treatment on the migraine-associated symptoms in a rat model of migraine. Experiments were carried out on 8 weeks, male Wistar rats. Chronic migraine was modeled by injection (10 mg/kg, i.p) of nitroglycerin (NTG) on days 3, 5, 7, and 9. CBL (2.5 and 5 ml/kg, i.p.) was injected every day for 10 days. Mechanical and thermal withdrawal thresholds of the hind paw were examined by von Frey hairs and hot plate, respectively. Head grooming behavior was evaluated one hour following injection of NTG. Light-aversive behaviors were determined in the modified elevated plus-maze (EPM) on even days and in the light/dark box on odd days. After behavioral experiments, blood concentrations of calcitonin gene-related peptide (CGRP), pituitary adenylate cyclase-activating polypeptide (PACAP), tumor necrosis factor-a (TNF-α), and interleukin-1β (IL-1β) were assessed by rat specific enzyme-linked immunosorbent assay (ELISA) kits. Our results indicated that NTG significantly increased migraine-related behavioral and molecular symptoms in the animals, whereas CBL treatment markedly reduced mechanical and thermal hyperalgesia, head grooming, and light-aversive behaviors induced by NTG. Also, blood levels of CGRP, PACAP, and pro-inflammatory cytokines (TNF-α and IL-1β) significantly decreased by CBL administration. Chronic CBL treatment showed antinociceptive and light-aversive reducing effects in the NTG-induced animal model of chronic migraine and may represent a valuable therapy for those suffering from migraine.