Ocimum basilicum leaf essential oil and (-)-linalool reduce orofacial nociception in rodents: a behavioral and electrophysiological approach

Antônio M. Venâncio, Murilo Marchioro, Charles S. Estavam, Mônica S. Melo, Marília T. Santana, Alexandre S.C. Onofre, Adriana G. Guimarães, Makson G. B. Oliveira, Péricles B Alves, Hugo de Carvalho Pimentel, Lucindo J. Quintans-Júnior
2011 Revista Brasileira de Farmacognosia  
The present study investigated the antinociceptive effects of Ocimum basilicum L. (Lamiaceae) leaf essential oil (LEO) and (-)-linalool (LIN) in formalin (2%)-, glutamate (25 μM)-and capsaicin (2.5 µg)-induced orofacial nociception models in mice. The involvement of these substances was further evaluated on the neuronal excitability of the hippocampal dentate gyrus. Male mice (n=8/group) were pretreated separately with LEO and by LIN (50, 100, and 200 mg/kg, i.p.), morphine (5 mg/kg, i.p.) and
more » ... 5 mg/kg, i.p.) and vehicle (saline + Tween 80 0.2%), before injection of nociceptive agent into the right upper lip (perinasal area). The LEO and LIN reduced the nociceptive face-rubbing behaviour in both phases on formalin test. LEO and LIN, at high doses, produced significantly antinociceptive effect in the capsaicin and glutamate tests. In hippocampal slices, LEO inhibited the population spike generated by stimulation of the hylus (antidromic stimulation), with an IC50 of 0.1±0.05 mg/mL. This response was reversibly blocked by lidocaine (0.5 mg/mL), a known voltage-dependent sodium channel antagonist and by LIN (0.5 mg/mL). Our results suggest that LEO and LIN modulate neurogenic and inflammatory pain in the tests of orofacial nociception induced by formalin, capsaicin and glutamate. Part of these effects may be associated with decreased peripheral and central neuronal excitability. Keywords : CNS excitability essential oil linalool Ocimum basilicum orofacial nociception Ocimum basilicum leaf essential oil and (-)-linalool reduce orofacial nociception in rodents -a behavioral and electrophysiological approach Antônio M. Venâncio et al. Rev. Bras. Farmacogn. Braz. J. Pharmacogn. 21(6): Nov./Dec. 2011 1044
doi:10.1590/s0102-695x2011005000147 fatcat:it76tx36lfasnj3sbpli7oc5ge