Antinociceptive and Gastro Protective Effects of Inhaled and Orally Administered Thevetia Peruviana Pers. K. Schum. Essential Oil

In Present study the antinociceptive and the gastroprotective effects of orally administered or inhaled Thevetia peruviana Pers. K. (Schum) (Oleander) volatile oil, and its principal constituents linalool and 1,8-cineole were evaluated in mice. Either when orally administered (100μl/kg) or inhaled for 60 min Thevetia peruviana volatile oil significantly reduced the acetic acid-writhing response in a naloxone-sensitive manner. In the hot plate test, analgesic activity observed after oil inhalation was inhibited by naloxone and atropine sulphate pretreatment suggesting the involvement of opioidergic as well as cholinergic pathways. Regardless of the administration route and the experimental model used both linalool and 1,8-cineole did not produce significant analgesic response. Oral or inhalatory treatment with analgesic doses of volatile oil did not affect mice spontaneous locomotors activity. Concerning the gastric effects, Oleander oil, linalool and 1,8-cineole oral administration protected against acute ethanol-induced gastric ulcers but did not prevent indomethacin-induced lesions indicating no interference with arachidonic acid metabolic cascade. In conclusion, besides this gastroprotection, Oleander oil reveals an interesting analgesic activity mainly relevant after inhalation, at doses devoid of sedative side effect, suggesting the interest for potential application of this oil in aromatherapy. INTRODUCTION: Volatile oils obtained from different species of Thevetia (T. peruviana, T. nerifolia, Nerium oleander) are frequently used in aromatherapy and massage to obtain many clinical benefits traditionally ascribed to their antibacterial, antifungal, carminative, sedative and antidepressant actions. Several studies have been conducted in order to validate these applications. In clinical trials oleander volatile oil demonstrated to improve sleep 1 and to reduce anxiety 2 . QUICK RESPONSE CODE DOI: 10.13040/IJPSR.0975-8232.6(10).4496-02 Article can be accessed online on: www.ijpsr.com DOI link: http://dx.doi.org/10.13040/IJPSR.0975-8232.6(10).4496-02 Furthermore, in animal models, it has been proved to possess anticancer 3 and HIV-1 Reverse Transcriptase and HIV-1 Integrase Inhibitory activity 4 . Volatile oil showed Anti-inflamatory 5 effect on smooth muscle in vitro supporting its use as Antibacterial, antitermite and analgesic agent. In the recent years, the study of natural products, as Oleander volatile oils, continues to attract researcher‟s attention in order to detect possible clinical uses and in particular, the list of oleander biological activities is increasing. Indeed, we have recently highlighted for oleander volatile oil an interesting antiplatelet activity associated with a promising protective effect in an animal model of acute pulmonary thromboembolism 6 . These whole oil activities are shared by its major components, linalool and 1,8-cineole. Experimental studies conducted with the terpenic alcohol linalool and