Evaluation of Unsaponifiable Fraction of Avocado Oil on Liver and Kidney Mitochondrial Function in Rats Fed a High-Fat and High-Carbohydrate Diet

Abstract

High-fat and high-carbohydrate (HF-HC) diets induce metabolic syndrome via mitochondrial dysfunction and oxidative stress. We have previously shown that this may be prevented by avocado oil, a source of bioactive molecules with antioxidant properties. However, it is unknown if these effects are mediated by the unsaponifiable fraction of avocado oil (UFAO). Thus, we tested if this fraction improves glucose metabolism, bioenergetics and oxidative stress in mitochondria from the kidney and liver of rats fed an HF-HC diet. We found that 12 weeks of an HF-HC diet impaired glucose utilization and increased insulin resistance, which was prevented by UFAO administration. The HF-HC diet decreased respiration, membrane potential and electron transport chain (ETC) function in liver and kidney mitochondria. These mitochondrial dysfunctions were prevented by UFAO intake. Unexpectedly, UFAO increased ROS levels in the mitochondria of control animals and did not decrease them in rats with an HF-HC diet; however, UFAO protects liver and kidney mitochondria from iron-induced oxidative stress. These findings suggest that impairments in glucose metabolism and mitochondrial function by an HF-HC diet may be prevented by UFAO, without decreasing ROS generation but protecting mitochondria from oxidative damage.

Keywords

• avocado oil
• unsaponifiable fraction
• high-fat diet
• high-carbohydrate diet
• metabolic syndrome
• mitochondria