Effet de l’huile d’argan sur la contractilité de l’aorte : susceptibilité au stress oxydatif

¹ Laboratoire de Nutrition et Alimentation, Faculté des Sciences BP : 133, Université Ibn Tofaïl, 14000 Kénitra, Maroc + 212 (0) 61 89 28 64 + 212 (0) 37 37 27 70
² Laboratoire Stress Cardio-Vasculaires et Pathologies Associées, Université Joseph Fourier, Grenoble, France
³ Equipe vitamines, INRA, Unité des maladies métaboliques et micronutriments, Saint-Genest-Champanelle

^* aguenaou@yahoo.com

Reçu : 1 Juillet 2005
Accepté : 1 Février 2006

Abstract

The aim of the present study was to evaluate the effect of long-term argan oil administration on vascular responsiveness and susceptibility to H₂O₂. 16 Wistar rats were divided into 2 groups; control group and treated group receiving 5 ml/kg/day of argan oil. After 8 weeks of treatment, vascular contractility was measured on isolated aortic rings from both groups by addition to the organ bath of cumulative concentration of vasoactive drugs (phenylephrine, acetylcholine and sodium nitroprussiate). In parallel, these isolated aortic rings were exposed to increasing doses of H₂O₂ (0, 1, 5 and 10 mM) for 20 minutes and the residual vascular response to phenylephrine (PE 10⁻⁶ M) and acetylcholine (Ach 10⁻⁶ M) was evaluated. Our results show that no significant differences between control and argan oil group were observed. Maximal contraction response to 10⁻⁶ MPE was 1.68 ± 0.20 g and 2.14 ± 0.20 g for control and argan oil groups, respectively. In precontracted isolated aortic rings, endothelium dependent relaxation to acetylcholine and endothelium-independent relaxation were not influenced by the diet. Maximal relaxation in response to 10⁻⁶M of Ach was 54 % for control group and 47 % for argan oil group. Addition of hydrogen peroxide (H₂O₂) to the organ bath for 20 minutes led to a dosedependent alteration of vascular reactivity, which was characterized by similar decrease in both the PE-induced contraction and the Ach-induced relaxation in the two experimental groups. These results suggest that argan oil treatment does not influence vascular reactivity nor its sensitivity to the oxidative stress.