Objective:

The aim of this project is to study the effects of cannabidiol on vascular cephalalgia induced by nitroglycerin in rats.

Background:

Migraines are headaches characterized by recurrent pain crises lasting from 4 o 72 hours. One of the processes that involve the pathophysiology of migraines is neurogenic inflammation, in which there is the release of vasodilatorneuropeptides, key mediators in the generation of pain. Cannabinoid receptors in the sensory nerve endings of the CNS have an inhibiting effect on neuronal activity, suggesting that the endocannabinoid system has the potential to moderate neurogenic inflammation and pain. 

Design/Methods:

A total of 35 Wistar rats supplied and housed in the FMABC Animal Facility were used. For this experiment we used the elevated plus maze as a paradigm of conditioned behavior, by exposing the animals receiving intraperitoneal administration of nitroglycerin to induce vascular cephalalgia to naturally aversive stimuli (open arms of the maze), where an open compartment will be associated (paired) with the previous ingestion of the potentially analgesic substances used in this study, thus shifting this environment from neutral to one paired with pain relief, according to the model by Latif et al. (2021). Animals were divided into 5 groups. G0 and 1: Saline solution 1ml/PO; G2: isolated cannabidiol 10mg/kg/PO; G3: Sumatriptan 0.6 mg/kg/SC; G4: Cafiaspirin®10 mg/kg/PO.

Results:

The groups treated with analgesics (CBD, Sumatriptan and Cafiaspirin) showed significant differences in time spent in the open arms in relation to control, but did not present significant differences when compared to each other. The longer the time spent in the open arm, the greater the analgesic effect of the drug.

Conclusions:

The effect of cannabidiol was equivalent to the other treatments used in this study for stopping cephalalgia.