Antinociceptive Activity and Redox Profile of the Monoterpenes (+)-Camphene, p -Cymene, and Geranyl Acetate in Experimental Models

Abstract

Objective . To evaluate antinocicpetive and redox properties of the monoterpenes (+)-camphene, p -cymene, and geranyl acetate in in vivo and in vitro experimental models. Methods . Evaluation of the in vitro antioxidant activity of (+)-camphene, p -cymene, and geranyl acetate using different free radical-generating systems and evaluation of antinociceptive actions by acetic acid-induced writhing and formalin-induced nociception tests in mice. Results . p -Cymene has the strongest antinociceptive effect, but (+)-camphene and geranyl acetate also present significant activity at high doses (200 mg/kg). (+)-Camphene had the strongest antioxidant effect in vitro at TBARS and TRAP/TAR assays and also had the highest scavenging activities against different free radicals, such as hydroxyl and superoxide radicals. Sodium nitroprussiate-derived NO production was enhanced by (+)-camphene. Geranyl acetate and p -cymene also presented some antioxidant effects, but with a varying profile according the free radical-generating system studied. Conclusion . (+)-Camphene, p -cymene, and geranyl acetate may present pharmacological properties related to inflammation and pain-related processes, being potentially useful for development of new therapeutic strategies, with limited possibilities for p -cymene and geranyl acetate.