Effect of Canola oil enrichment with microconsituants against metabolic disorders

Abstract

Aim/hypothesis: Insulin resistance (IR) favors the progression of metabolicsyndrome (MetS) and increases the risk of type2 diabetes. IR results from metabolic dysfunctions,oxidative stress and inflammation caused by ectopic fat depots. We studied the effect of canola oil enriched with micronutrients naturally present in canola seed on IR and MetS during a high fat (HF)-challenge]. Research design and Methods: Rats were fed with a HF diet containing 30% of lipids, mainly derived from palm oil (diet P) or from a mixture of palm and canola oils (60:40, diet C). In 2 groups of animals, diet C was further supplemented with alpha tocopherol, CoQ with or without Canolol (diets CMC & CM respectively). Insulin sensitivity and glucose tolerance were assessed after 10 weeks. Tissue sampling was carried at sacrifice for gene expression analysis (RT-qPCR), protein expression level (Western-Blot), fatty acid composition (Gas Chromatography). HF animals were compared to control animals receiving a standard diet. ANOVA was performed for statistical analysis (followed by adjusted Fisher post-hoc test when p<0.05).Results: All groups receiving a HF diet gained significantly more weight and accumulated fat mass compared to control (No difference between all HF groups). Glucose tolerance was altered in P and C groups and resored in CM and CMC. Insulin sensitivity and muscle Akt activition were not different between control and P groups, but were increased in CMC group compared to controls. No marked changes in plasma antioxidant defense were detected. A reduction in PDK4 and Srebp1c mRNA levels was observed in skeletal muscle in CM group.Conclusions: The proportion of AGPI could not prevent metabolic disturbance induced by a HF meal. Enrichment with natural micronutrients could have a small but beneficial effect against insulin resistance. These effects might be linked to a better glucose oxidation in skeletal muscl