Efeitos do óleo de pequi (Caryocar brasiliense Camb.) sobre a aterogênese e o estresse oxidativo em camundongos LDL receptor knockout alimentados com dieta aterogênica

Abstract

The Caryocar brasiliense, or pequi, is a popular food in northeastern of Brazil. The oil extracted from pequi has a high concentration of both monounsaturated and saturated fatty acids. The first one is a well established antiatherogenic factor, although the second one is associated with increased risk of atherosclerosis. The high amount of carotenoids and phenolic compounds in pequi oil, gives it antioxidant properties, which is also a beneficial factor in atherogenesis. Thus, our objective was to study the effect of pequi oil on lipid metabolism, atherosclerosis and oxidative stress in experimental model of atherosclerosis. The LDL receptor deficient mice were divided into control and pequi oil groups, receiving soybean or pequi oil supplemented atherogenic diet, respectively. After 6 experimental weeks, animals from pequi oil group showed a worse lipid profile when compared to the control one. The atherosclerotic lesion was also increased in the aortic sinus in the group receiving oil from pequi. Surprisingly, when the early lesions presented in thoracic/abdominal aorta were analyzed, we found a reduction of the atherosclerotic lesion in animals fed on pequi oil. The pequi oil group also showed a lower oxidative stress, indicated by the reduction on lipid peroxidation and decreased serum concentrations of anti-oxidized LDL antibody. In an ex vivo experiment using macrophages extracted from animal peritoneum showed a reduction in the release of reactive oxygen species in pequi oil group. Based on these data, we suggest that the pequi oil, due to its antioxidant activity and content of monounsaturated fat, slows atherogenesis in initial stages (as seen in aortic lesions). However, the increasing of serum cholesterol and atherogenic fractions induced by its high content of palmitic acid, induces a more important LDL migration toward intima of arteries, increasing a larger and more mature atherosclerotic plaque. In conclusion, pequi oil supplemented diet is a risk factor for dislipidemia and atherosclerosis, despite its antioxidant action, and it is not indicated for patients with increased risk of acute myocardial infarction or advantaged atherosclerosis.