Amelioration of oxidative and inflammatory status in hearts of cholesterol-fed rats supplemented with oils or oil-products with extra virgin olive oil components

The contribution of extra virgin olive oil (EVOO) macro- and micro-constituents in heart oxidative and inflammatory status in a hypercholesterolemic rat model was evaluated. Fatty acid profile as well as alpha-tocopherol, sterol, and squalene content was identified directly in rat hearts to distinguish the effect of individual components or to enlighten the potential synergisms. Oils and oil-products with discernible lipid and polar phenolic content were used. Wistar rats were fed a high-cholesterol diet solely, or supplemented with one of the following oils, i.e., EVOO, sunflower oil (SO), and high-oleic sunflower oil (HOSO) or oil-products, i.e., phenolics-deprived EVOO [EVOO(-)], SO enriched with the EVOO phenolics [SO(+)], and HOSO enriched with the EVOO phenolics [HOSO(+)]. Dietary treatment lasted 9 weeks; at the end of the intervention blood and heart samples were collected. High-cholesterol-diet-induced dyslipidemia was shown by increase in serum total cholesterol, low-density lipoprotein cholesterol, and triacylglycerols. Dyslipidemia resulted in increased malondialdehyde (MDA) and tumor necrosis factor-alpha (TNF-alpha) levels, while glutathione and interleukin 6 levels remained unaffected in all intervention groups. Augmentation observed in MDA and TNF-alpha was attenuated in EVOO, SO(+), and HOSO(+) groups. Heart squalene and cholesterol content remained unaffected among all groups studied. Heart alpha-tocopherol was determined by oil alpha-tocopherol content. Variations were observed for heart beta-sitosterol, while heterogeneity was reported with respect to heart fatty acid profile in all intervention groups. Overall, we suggest that the EVOO-polar phenolic compounds decreased MDA and TNF-alpha in hearts of cholesterol-fed rats.