Rhynchophylline attenuates migraine in trigeminal nucleus caudalis in nitroglycerin-induced rat model by inhibiting MAPK/NF-кB signaling

Migraine causes severe health and social issues worldwide. Rhynchophylline (Rhy) is one of the major active components of Uncaria rhynchophylla that is used for the treatment of headache in Traditional Chinese Medicine. In the current study, the effect of Rhy on nitroglycerin (NTG)-induced migraine was assessed and the associated mechanism was also explored to explain its function. Rats were pre-treated with Rhy of two doses (10 mg/kg and 30 mg/kg) and then subjected to NTG to induce migraine symptoms. Thereafter, the electroencephalogram (EEG) signaling, spontaneous behaviors, levels of indicators related to oxidative stress, and expression of Calcitonin gene-related peptide (CGRP) were measured to assess the anti-migraine function of Rhy. Moreover, the activities of MAPK/NF-κB pathway under the administrations of Rhy were also detected. The results showed that NTG induced EEG and behavior disorders in rats, which was associated with the initiation of oxidative stress and increased expression of CGRP. Nevertheless, the pre-treatments with Rhy attenuated the damages induced by NTG by reversing the levels of all the above indicators. The results of western blotting demonstrated that the anti-migraine effect of Rhy was accompanied by the inhibition of MAPK/NF-кB pathway. The findings outlined in the current study revealed an alternative mechanism of Rhy in protecting brain tissues against migraine: the agent exerted its effect by suppressing MAPK/NF-кB pathway, which would ameliorate impairments associated with migraine.