(LB03-16-24) Protective Hepatic Effects of Extra Virgin Olive Oil and Exercise Training in Diet-Induced Obese Rats

Objectives: A diet rich in saturated fat is associated with obesity and chronic inflammation. Extra-virgin olive oil (EVOO) contains natural phenolics, like oleocanthal (Oleo) and oleacein (Olea). Due to its potent antioxidant and anti-inflammatory properties, research suggests that incorporating EVOO along with exercise can ameliorate high-fat diet (HFD)-induced obesity and inflammation. However, the underlying mechanism is unknown. We hypothesized that (1) consumption of EVOO contains varying amounts of Oleo/Olea dose-dependently ameliorates inflammation and lipid metabolism in liver dose-dependently, and (2) the combination of EVOO and exercise enhances hepatic protection in HFD-induced obese Sprague-Dawley (SD) rats.

Methods: Female SD rats were divided into 5 treatment groups: HFD (43% of calories from milkfat), HFD supplemented with EVOO contains low Oleo/Olea (43% calories from EVOO contained 100 mg/L Oleo/Olea, LO), low EVOO + exercise (LO+E), HFD supplemented with EVOO contains high Oleo/Olea (43% calories from EVOO contained 1000 mg/L Oleo/Olea, HO), and a high EVOO + exercise (HO+E). Body weight was measured, and liver was collected after the intervention for gene expression analysis. Statistical analyses were performed using one-way analysis of variance by Prism GraphPad 10.1.2.

Results: After 12-week intervention, body weight of HO group was significantly lower than that of HFD (P < 0.01) and HO+E group (P < 0.05). In the liver, mRNA expression levels of inflammatory genes, like interleukin-6 (IL-6) were lower in rats in the LO and HO groups compared to those on HFD, in a dose-dependent manner. The addition of exercise further augmented this effect (HFD vs HO+E, p= 0.0152). Moreover, we observed the protective effect of the EVOO and exercise combination, evidenced by a decrease in lipid synthetic genes, like acetyl-CoA carboxylase (ACC, HFD vs HO+E, p= 0.0152), and an increase in lipid metabolic genes, like carnitine palmitoyltransferase 2 (CPT 2. HFD vs HO+E, p= 0.0802).

Conclusions: EVOO with high amount of Oleo/Olea, when combined with exercise, confers protection against diet-induced inflammation and enhances fatty acid oxidation. This indicates the significance of incorporating EVOO, with exercise, as potential therapeutic targets in preventing diet-induced hepatic-related disorders.

Funding Sources: TTU College of Human Sciences Seed Grant