Combined effects of cannabidiol and Δ9-tetrahydrocannabinol alleviate migraine-like symptoms in mice

Background The therapeutic use of cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC) to treat migraine has been understudied. Using three mouse models, we examined the impact of CBD and THC on migraine-relevant behaviors triggered by: 1) calcitonin gene-related peptide (CGRP), 2) sodium nitroprusside (SNP), and 3) cortical spreading depolarization (CSD). Methods Both male and female CD1 mice were treated with CBD (100 mg/kg) or THC (1 mg/kg) alone or in combinations of CBD (1, 30 or 100 mg/kg) and THC (1 mg/kg) prior to injection of CGRP or SNP. The mice were assessed for light aversion (photophobia), squint (non-evoked pain), and periorbital tactile hypersensitivity, as well as possible adverse effects. In a separate set of experiments, CSD events were optogenetically induced in familial hemiplegic migraine 1 (FHM1) mutant and wildtype littermates (WT) mice (C57BL/6 background), followed by grimace and motor assessments with and without combinations of CBD (30 or 100 mg/kg) and THC (1 mg/kg). Results In CD1 mice, a 100:1 CBD:THC combination mitigated light aversion induced by CGRP and SNP in males and females. Rescue of CGRP- and SNP-induced squint was observed only in male mice with 100:1 CBD:THC. None of the treatments rescued periorbital tactile hypersensitivity in either sex. In FHM1 mutant and WT mice, the 100:1 CBD:THC ratio did not affect CSD characteristics but did reduce CSD-induced grimace features (i.e., head pain mimic). No adverse effects of any of the cannabinoid treatments were observed using cognitive, emotional, or motor tests. Conclusions A 100:1 ratio of CBD:THC has a beneficial effect on some of the most bothersome migraine-related symptoms in three mouse models. Our findings support a potential therapeutic efficacy of combined CBD and THC treatments.