Molecular mechanism underlying orofacial antinociceptive activity of Vanillosmopsis arborea Baker (Asteraceae) essential oil complexed with β-cyclodextrin.

BACKGROUND: Vanillosmopsis arborea Baker has recognized economic value owing to the high content of (-)-α-bisabolol (BISA) in the essential oil of its stem (EOVA). The antinociceptive effect of EVOA has already been demonstrated, and β-cyclodextrin (βCD) is known to improve the analgesic effect of various substances.

PURPOSE: Thus, we aimed to evaluate the orofacial antinociceptive effect of a complex containing EOVA-βCD in rodents.

METHODS: EOVA was obtained by simple hydrodistillation, and the essential oil was complexed with βCD. The animals (n = 6/group) were treated orally with EOVA-βCD (10 or 50 mg/kg), or vehicle (control), and subjected to cutaneous orofacial nociception (formalin, capsaicin, acidic saline or glutamate), corneal (hypertonic saline) or temporomandibular (formalin) tests. The expression of FOS protein was analyzed in the spinal cord. Molecular docking was performed using the 5-HT3 and M2 receptors and BISA.

RESULTS: The oral administration of EOVA-βCD reduced nociceptive behaviour. Moreover, EOVA-βCD decreased FOS expression. The molecular docking study indicates that BISA interacts with 5-HT3 and M2 receptors, indicating the potential mechanism of action of the tested compound.

CONCLUSIONS: Our results indicate that EOVA-βCD possesses orofacial antinociceptive effect, indicating that this complex can be used in analgesic drug development.