Beneficial effect of galanin on insulin sensitivity in muscle of type 2 diabetic rats

Abstract Objective. We investigated the effects of magnesium supplementation on glucose tolerance, insulin sensitivity, oxidative stress as well as the concentration of insulin receptor and glucose transporter-4 in streptozotocin-nicotinamide induced type-2 diabetic (T2D) rats. Methods. Rats were divided into four groups designated as: 1) control (CTR); 2) diabetic untreated (DU); 3) diabetic treated with 1 mg of Mg/kg diet (Mg1-D); and 4) diabetic treated with 2 mg of Mg/kg diet (Mg2-D). T2D was induced with a single intraperitoneal (i.p.) injection of freshly prepared streptozotocin (55 mg/kg) aft er an initial i.p. injection of nicotinamide (120 mg/kg). Glucose tolerance, insulin sensitivity, lipid profile, malondialdehyde (MAD) and glutathione content, insulin receptors (INSR) and glucose transporter-4 (GLUT4), fasting insulin and glucose levels were measured, and insulin resistance index was calculated using the homeostatic model assessment of insulin resistance (HOMA-IR). Results. Magnesium supplementation improved glucose tolerance and lowered blood glucose levels almost to the normal range. We also recorded a noticeable increase in insulin sensitivity in Mg-D groups when compared with DU rats. Lipid perturbations associated T2D were significantly attenuated by magnesium supplementation. Fasting glucose level was comparable to control values in the Mg-D groups while the HOMA-IR index was significantly lower compared with the DU rats. Magnesium reduced MDA but increased glutathione concentrations compared with DU group. Moreover, INSR and GLUT4 levels were elevated following magnesium supplementation in T2D rats. Conclusion. These findings demonstrate that magnesium may mediate effective metabolic control by stimulating the antioxidant defense, and increased levels of INSR and GLUT4 in diabetic rats.

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Zhenqing Recipe Improves Glucose Metabolism and Insulin Sensitivity by Repressing Hepatic FOXO1 in Type 2 Diabetic Rats

The American Journal of Chinese Medicine ◽

10.1142/s0192415x12500541 ◽

2012 ◽

Vol 40 (04) ◽

pp. 721-733 ◽

Cited By ~ 9

Author(s):

Wenfan Huang ◽

Jie Yu ◽

Xuming Jia ◽

Liang Xiong ◽

Ningxu Li ◽

...

Keyword(s):

Insulin Sensitivity ◽

Glucose Metabolism ◽

Mrna Expression ◽

Diabetic Rats ◽

Control Group ◽

Oral Glucose ◽

Sensitivity Index ◽

Mrna Levels ◽

Type 2 Diabetic

Forkhead box O1 (FOXO1) plays an important role in glucose metabolism at the gene transcription level. Increased FOXO1 activity results in hyperglycemia by promoting the expression of gluconeogenic enzymes such as phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase), and inhibiting glucokinase (GK). This study evaluates the effect of Zhenqing Recipe (ZQR), a Chinese herbal medicine, on hyperglycemia and its molecular mechanisms. Type 2 diabetic rats, developed by high-fat diet combined with low-dose STZ injections, were randomly divided into untreated diabetic, ZQR and metformin group. Normal rats served as control. After an eight-week treatment, fasting blood glucose was significantly decreased and insulin sensitivity index was obviously increased in the ZQR group. ZQR also improved the oral glucose tolerance. Compared with the control group, the mRNA levels of PEPCK and G6Pase were significantly elevated, while GK mRNA expression was decreased in the liver of untreated diabetic rats. ZQR significantly reduced the mRNA levels of PEPCK and G6Pase, and increased GK mRNA expression. The hepatic mRNA and protein expression of FOXO1 in the untreated diabetic group was markedly increased compared to controls. The administration of ZQR significantly decreased the mRNA and protein levels of hepatic FOXO1. The data suggest that ZQR improves glucose metabolism and insulin sensitivity, which is accompanied with regulating mRNA expression of GK and gluconeogenic genes. This anti-diabetic effect of ZQR is due to its ability to repress hepatic FOXO1 at the mRNA and protein level.

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Infusion of Mesenchymal Stem Cells Ameliorates Hyperglycemia in Type 2 Diabetic Rats: Identification of a Novel Role in Improving Insulin Sensitivity

Diabetes ◽

10.2337/db11-1141 ◽

2012 ◽

Vol 61 (6) ◽

pp. 1616-1625 ◽

Cited By ~ 125

Author(s):

Y. Si ◽

Y. Zhao ◽

H. Hao ◽

J. Liu ◽

Y. Guo ◽

...

Keyword(s):

Stem Cells ◽

Mesenchymal Stem Cells ◽

Insulin Sensitivity ◽

Diabetic Rats ◽

Type 2 Diabetic

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Antidiabetic Effect ofMonolluma quadrangulaIs MediatedviaModulation of Glucose Metabolizing Enzymes, Antioxidant Defenses, and Adiponectin in Type 2 Diabetic Rats

Oxidative Medicine and Cellular Longevity ◽

10.1155/2019/6290143 ◽

2019 ◽

Vol 2019 ◽

pp. 1-11 ◽

Cited By ~ 3

Author(s):

May N. Bin-Jumah

Keyword(s):

Insulin Sensitivity ◽

Glucose Tolerance ◽

Liver Lipid ◽

Diabetic Rats ◽

Antioxidant Defenses ◽

Metabolic Disturbances ◽

Metabolizing Enzymes ◽

Antidiabetic Effect ◽

Type 2 Diabetic

Monolluma quadrangulais a succulent bush traditionally used to treat diabetes and peptic ulcer. The present study aimed to investigate the effect ofM. quadrangulahydroethanolic extract on glucose tolerance, insulin sensitivity, glucose metabolizing enzymes, lipid profile, and adiponectin expression in type 2 diabetic rats. In addition, the study evaluated the antioxidant and anti-inflammatory activities of theM. quadrangulaextract. Type 2 diabetes was induced by feeding rats a high-fat diet (HFD) for 8 weeks followed by 30 mg/kg streptozotocin (STZ). Diabetic rats received 300 or 600 mg/kgM. quadrangulaextract for 4 weeks. HFD/STZ diabetic rats showed impaired glucose tolerance, reduced insulin secretion, and insulin resistance. HFD and STZ induced a significant increase in serum cholesterol, triglycerides and proinflammatory cytokines, and liver lipid peroxidation. Treatment withM. quadrangulaextract ameliorated these metabolic disturbances and increased liver glycogen, hexokinase activity, and antioxidants.M. quadranguladeclined the activity of liver glucose-6-phosphatase and fructose-1,6-biphosphatase. In addition,M. quadrangulaextract increased serum adiponectin levels and hepatic adiponectin expression in HFD/STZ diabetic rats. In conclusion,M. quadrangulaexerts antidiabetic effect mediatedviaameliorating glucose tolerance, insulin sensitivity, glucose metabolizing enzymes, and antioxidant defenses. Increased adiponectin levels and expression seems to mediate, at least in part, the antidiabetic effect ofM. quadrangula.

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