Antioxidant and anti-inflammatory properties of gamma- oryzanol attenuates insulin resistance by increasing GLUT- 4 expression in skeletal muscle of obese animals

Abstract

Background: Skeletal muscle is the most important organ for whole-body glucose homeostasis. However, it has been suggested that obesity-related inflammation could be involved in insulin resistance and diabetes mellitus type 2 (DM2) development due several mechanisms, among them, the reduced expression of the glucose transporter type 4 (GLUT-4). Gamma-oryzanol (γOz) is a compound present in the whole grain of rice that presents anti-inflammatory and antioxidant activities. The aim of this study was to verify if the effect antioxidant and anti-inflammatory of yOz attenuate insulin resistance in skeletal muscle of obese rats by increasing GLUT- 4 expression. Methods: Male Wistar rats (±187 g) were initially randomly distributed into 2 experimental groups (control, n = 6, and high sugar-fat diet (HSF), n = 12) for 20 weeks. At week 20th of this study, once obesity and insulin resistance were detected in the HSF group, animals were divided to begin the treatment with γOz or continue receiving HSF for 10 more weeks. At the end it was analyzed nutritional, metabolic, inflammatory and oxidative stress parameters and GLUT-4 protein expression. Results: The treatment improved insulin resistance, reduced inflammation, increased antioxidant response and GLUT-4 expression. Conclusion: It is possible to conclude that the antioxidant and anti-inflammatory activity of yOz attenuates insulin resistance by increasing GLUT-4 expression in skeletal muscle of obese animals.