Quercitrin, a bioflavonoid improves glucose homeostasis in streptozotocin‐induced diabetic tissues by altering glycolytic and gluconeogenic enzymes

Abstract

The present study is an investigation into the role of quercitrin on carbohydrate metabolism in normal and streptozotocin (STZ)-induced diabetic rats. Administration of STZ leads to a significant increase (P < 0.05) in fasting plasma glucose and a decrease in insulin levels. The content of glycogen is significantly decreased (P < 0.05) in liver and muscle, but increased in the kidney. The activity of hexokinase decreased whereas the activities of glucose 6-phosphatase and fructose 1,6-bisphosphatase significantly increased (P < 0.05) in the tissues. Oral administration of quercitrin (30 mg/kg) to diabetic rats for a period of 30 days resulted in significant (P < 0.05) alterations in the parameters studied but not in normal rats. A decrease of plasma glucose and increase in insulin levels were observed along with the restoration of glycogen content and the activities of carbohydrate metabolic enzymes in quercitrin-treated diabetic rats. The histopathological study of the pancreas revealed the protective role of quercitrin. There was an expansion of the islets and decreased fatty infiltrate of the islets in quercitrin treated diabetic rats. In normal rats treated with quercitrin, we could not observe any significant change in all the parameters studied. Combined, these results show that quercitrin plays a positive role in carbohydrate metabolism and antioxidant status in diabetic rats.

Potent Natural Inhibitors of Alpha-Glucosidase and Alpha-Amylase against Hyperglycemia <em>in Vitro </em>and <em>in Vivo</em>

“…In one study has demonstrated that many polyphenolic compounds display a role alpha-amylase inhibitory activity [65] such as Catechin and Rutin [14] while Quercetin is bioflavonoid that has been used for relieving hyperglycemia activity to lead glucose homeostasis. [66] The alkaloids exhibited inhibitory activity against alpha-glucosidase, aldose reductase, alpha-amylase, and lipase. The flavonoids also showed mild inhibition on alpha-glucosidase, aldose reductase, alpha-amylase, and lipase.…”

Quercetin can reduce insulin resistance without decreasing adipose tissue and skeletal muscle fat accumulation

“…The authors of those studies which found positive effects of quercetin on glycemic control proposed several mechanisms to explain the beneficial effect of this polyphenol: (a) the anti-oxidative protective action on the pancreatic islets (Coskun et al 2005;Babujanarthanam et al 2010;Jeong et al 2012), (b) the increase in adiponectin circulating concentration (Wein et al 2010), (c) the inhibition of small intestine glucosidase activity , (d) the reduction in the intestinal glucose absorption mediated by GLUT2 (Kwon et al 2007), (e) the increase in glucokinase activity (Vessal et al 2003) and (f) the increase in GLUT4 transporters in skeletal muscle (Jung et al 2011;Shen et al 2012;Anhê et al 2012).…”

Quercetin But Not Quercitrin Ameliorates Tumor Necrosis Factor-Alpha-Induced Insulin Resistance in C2C12 Skeletal Muscle Cells

“…19) In addition, the majority of studies focus on the aglycone form (quercetin), and the glycoside form (quercitrin) attracts little attention due to the lack of commercial standards. 20) In this study, we aimed to investigate the effects of the aglycone (quercetin) and rhamnose glucoside (quercitrin) in TNF-α-induced insulin resistance in C2C12 murine skeletal myoblasts. As several studies on quercetin in diabetes have focused on the oxidative injury of tissues like pancreas or liver, 21,22) this study investigated the role of quercetin in insulin sensitivity from a relatively novel perspective.…”