Antinociceptive Effect of Volatile Oils from Ocimum basilicum Flowers on Adult Zebrafish

The species Ocimum basilicum L., Lamiaceae, is popular for culinary purposes and medicinal use as a larvicide, repellent, antifungal, and antimicrobial agent. Therefore, the aim of the present study is to evaluate the chemical composition and antinociceptive effect of the volatile oil of O. basilicum flowers using adult zebrafish (Danio rerio) (n = 6/group) treated orally (20 µl) with volatile oil (0.25, 1.25, or 2.5 mg/ml; 20 µl) or vehicle (0.9% NaCl, 20 µl). The volatile oil of the O. basilicum flowers was obtained by hydrodistillation and analyzed by GC–MS, and the antinociceptive action is evaluated by different stimuli using motor parameters. The analysis of the chemical profile identified fourteen components with linalool (1) as a major chemical constituent (56.37%). The oral administration of volatile oil did not show any acute toxicity or behavior effects in all tested doses. The volatile oil has a pharmacological potential for the treatment of acute pain by modulation of opioid system, N-methyl-d-aspartate receptors (glutamatergic receptor), and the transient receptor potential vanilloid subtype 1 and acid-sensing ion channels. Together, these data provide support for analgesic properties of the volatile oil and contribute to suggest that the adult zebrafish model presents the cheapest, cost-effective pharmacological alternative for the discovery of novel analgesics.