Protective potential of fish oil supplementation against insulin resistance and pancreatic islet damage in STZ-induced Wistar rats

Abstract

Background: Fish oil, which is regarded as the primary source of omega-3 fatty acids, has been long studied for its potential as an antidiabetic therapy. However, its protective ability against insulin resistance and pancreatic islet alteration remains unclear and controversial. Aim: To investigate the beneficial effects of fish oil consumption on the progression of insulin resistance and pancreatic islet dysfunction in a rat model of diabetes. Methods: Diabetic rats model (n=30) were divided into 5 groups and received; 1) NS injection+NS oral (NC); 2) NS injection+3g/kg fish oil (FC); 3) STZ injection+NS oral (DC); 4) STZ injection+1g/kg fish oil (DFO1) and 5) STZ injection+3g/kg fish oil (DFO3). Fasting blood insulin was analyzed by commercial rat insulin ELISA assay; meanwhile, the determination of insulin sensitivity was calculated by HOMA-IR and HOMA-B. A histological study was conducted on pancreas tissue using H & E staining. Results: Fish oil supplementation reduced hyperglycemia and ameliorated HOMA IR in STZ-induced animal models indicating that fish oil supplementation improved insulin sensitivity. Furthermore, animals treated with fish oil at a dose of 3g/kg (DFO3) showed an enhancement in pancreatic islets, which was displayed by less abnormal structures than diabetic control animals (DC). This could imply that the administration of fish oil, especially rich in bioactive omega-3 fatty acids effectively inhibits insulin resistance and restore islet of Langerhans alteration in rats injected with STZ. Conclusion: Thus, the current study suggested that fish oil supplementation could support the treatment of diabetes but should not be considered as an alternative therapy.