Insulin Resistance and Adipocytokine Levels in High Fat High Fructose-Fed Growing Rats: Effects of Cinnamon

Abstract

The main objective of this study was to investigate the effects of high fat high fructose (HF/HFr) diet on the onset of the characteristics of the metabolic syndrome and the levels of some adipocytokines in growing male and female rats. Also we aimed to study the possible protective effects of cinnamon (CN) against HF/HFr diet induced-metabolic disturbances. Forty eight growing Sprague-Dawley rats were randomly assigned into 4 groups (12 rats/group; 6 males + 6 females) and were fed for a period of 6 weeks the following diets (i) basal diet, control (C) (ii) basal diet containing 20 g CN/kg diet (C+CN). (iii) high fat diet (15% beef tallow + 5% corn oil) combined with fructose (13% W/V) in drinking water (HF/HFr), (iv) HF/HFr diet containing 20 g CN/kg diet (HF/HFr+CN). HF/HFr diet resulted in elevated levels of fasting blood glucose, serum insulin, and homeostasis model assessment (HOMA) index along with impaired glucose tolerance, as well as elevated serum triacylglycerols (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), resistin, leptin, tumor necrosis factor-α (TNF-α) and total oxidant capacity (TOC) with a decrease in high-density lipoprotein cholesterol (HDL-C) and total antioxidant capacity (TAC) compared to control. These deleterious effects were more pronounced in male than female rats. Cinnamon reinstated most of the altered measured parameters. So, HF/HFr diet developed characteristics of metabolic syndrome in growing male and female rats. Females were protected against some metabolic disturbances of HF/HFr diet. The inclusion of cinnamon in the diet was effective in modulating some aspects of metabolic parameters associated with metabolic syndrome.

Keywords: Metabolic syndrome; fructose; fats; adipocytokines; rats