Germinated Waxy Black Rice Ameliorates Hyperglycemia and Dyslipidemia in Streptozotocin-Induced Diabetic Rats

Abstract

This study aimed to examine the anti-diabetic effect of germinated waxy black rice (GWBR) using streptozotocin (STZ)-induced diabetic rats. In the diabetic rats, GWBR supplementation for 8 weeks reduced plasma blood glucose concentrations, improved glucose clearance and prevented diabetes-induced weight loss. Rats with STZ-induced diabetes who received GWBR supplementation exhibited decreased expression of sodium-dependent glucose transporter 1 (SGLT1) and glucose transporter (GLUT) 2 genes and proteins in the small intestine via decreases in hepatocyte nuclear factor (HNF)-1α, HNF-1β, and HNF-4α, transcriptional factors that are involved in the regulation of SGLT1 and GLUT2, compared with the rats with STZ-induced diabetes that did not receive GWBR supplements. GWBR supplementation also enhanced the expression of GLUT4 and the genes and proteins involved in GLUT4 translocation, such as insulin receptor (IR) and insulin receptor substrate 1 (IRS1), and increased the phosphorylation of phosphoinositide 3-kinase (PI3K) and protein kinase B (PKB, Akt) proteins in skeletal muscle. GWBR further increased glycogen synthase (GS) 1 by decreasing glycogen synthase kinase (GSK)-3β in skeletal muscle. Interestingly, GWBR recovered STZ-impaired pancreatic β-cells, resulting in increased insulin synthesis and secretion. In addition, GWBR reduced serum triglyceride, total cholesterol, low-density lipoprotein cholesterol, aspartate transferase and alanine transferase concentrations and increased high-density lipoprotein cholesterol concentrations. Taken together, these findings suggest that GWBR could be a candidate for improving the diabetic condition by regulating glucose uptake in the intestine and muscle and regulating the secretion of insulin from the pancreas.

Effect of Peroxisome Proliferator-Activated Receptor-Alpha-Agonists on Diabetes-Induced Acute Kidney Injury: Role of Oxidative Stress and Hyperlipidemia

“…In the present study, the increase in serum concentration of total cholesterol and triglycerides and a decrease in HDL and increase in serum concentration were noted in both diabetic rats when compared with normal rats, which indicates both diabetes induced-hyperlipidemia. Similar kind of lipid abnormality has been noted by previous reports on the same model [23,24].…”

“…The diabetes-induced alteration in lipid profile such as hypercholesterolemia and hypertriglyceridemia affect the function of the glomerulus and produce glomerulosclerosis, which results in diabetic nephropathy [24]. Further, insulin has an inhibitory action on 3-hydroxy-3-methyl-glutaryl-Co-A (HMG-COA) reductase, a key rate-limiting enzyme involved in the synthesis of cholesterol.…”

miR-140-5p Aggravates Insulin Resistance via Directly Targeting GYS1 and PPP1CC in Insulin-Resistant HepG2 Cells

“…By activating glycogen synthase phosphatase, insulin activates GYS, increases the ability of liver and muscle to synthesize glycogen, inhibits the production of endogenous glucose and stimulates the uptake of glucose in peripheral tissues. [44][45][46] Protein phosphatase 1 (PP1) is the main phosphatase in the insulin-activated glycogen synthase pathway, consisting of 37KDa catalytic subunit (PPlC) and 126KDa regulatory subunit (PPlG). 47 For personal use only.…”

Glucose transporters in the small intestine in health and disease

“…Antidiabetic properties have been associated with foods containing flavonoids and other phenolic compounds such as strawberries and blueberries, yerba maté, and germinated waxy black rice [68,141,186,285,328,419]. Evidence has been presented that such foods or extracts thereof inhibit and/ or downregulate small intestinal glucose transporters.…”

“…When normal rats or rats with alloxan-induced T1DM were gavaged during 4 weeks with extract of Yerba maté (Ilex paraguariensis), the expression of Sglt1 mRNA in the small intestine related to mRNA of β-actin was decreased [285]. Furthermore, the expression of Sglt1 and Glut2 in rats with STZ-induced T1DM was decreased on mRNA and protein levels when the food was supplemented for 8 weeks with germinated waxy black rice [186]. Although specific foods or food extracts may have beneficial effects, usage of the effective food components is preferred for practical and security reasons.…”