Modulatory effect of inulin with soya isoflavones on plasma lipid profile and liver SCD-18 index in rats with induced type-2 diabetes mellitus

Abstract

Obesity and type-2 diabetes are often associated with nonalcoholic fatty liver disease (NAFLD). Soya isoflavones act as antidiabetic agents and protect against NAFLD. There are data suggesting that inulin may increase the plasma concentration and effect of soya isoflavones. The aim of the present study was to compare the effect of soya isoflavones, as opposed to the effect of soya isoflavones with inulin, on plasma lipid profile, liver morphology, and liver fatty acids in rats with induced type-2 diabetes mellitus. Data were collected on thirty-six male Sprague- Dawley rats divided into control and diabetic groups. Animals in the diabetic (DM) group were on a high-fat diet and were injected with low doses of streptozotocin. Animals in the control groups were fed a regular diet and were injected with a buffer. After the injections, the animals were divided into three groups of nondiabetic rats (nDM)-controls (c-nDM), rats treated with isoflavones (IS-nDM), and rats treated with isoflavones plus inulin (IS+IN-nDM)-and three parallel diabetic (DM) subgroups: controls (c-DM), rats treated with isoflavone (IS-DM), and rats treated with isoflavones plus inulin (IS+IN-DM). Hepatic steatosis and fibrosis were examined using hematoxylin-eosin staining and Mallory’s trichrome methods respectively. Liver fatty acids were extracted and analyzed by gas chromatography. A lipid blood test was performed. The study showed significant changes in liver fatty acids, liver morphology, and plasma lipid profile. The estimated SCD-18 index significantly decreased in both the control and DM groups after isoflavone supplementation. The level of liver steatosis and fibrosis also decreased after isoflavone supplementation in the DM groups. The plasma lipid profile showed increased levels of HDL-C after isoflavone supplementation in the DM groups. These results support the protective use of isoflavones in liver steatosis and as beneficial to plasma lipid profile in individuals with diabetes. A novelty of this work is its comparison of supplementation using soya isoflavones with supplementation using both soya isoflavones and inulin. Surprisingly, additional supplementation with inulin modulates the positive effect of isoflavones