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Astragalus polysaccharides alleviates glucose toxicity and restores glucose homeostasis in diabetic states via activation of AMPK.

Zou F, Mao XQ, Wang N, Liu J, Ou-Yang JP - Acta Pharmacol. Sin. (2009)

Bottom Line: The hyperglycemia status, insulin sensitivity, glucose uptake, and activation level of AMPK in diabetic rats were improved in response to APS administration.APS could also alleviate glucose toxicity in cultured mouse cells by the activation of AMPK.APS can alleviate glucose toxicity by increasing liver glycogen synthesis and skeletal muscle glucose translocation in the T2DM rat model, via activation of AMPK.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathophysiology, Medical College of Wuhan University, Wuhan, China.

ABSTRACT

Aim: To establish the mechanism underlying the improvement of glucose toxicity by Astragalus polysaccharide (APS), which occurred via an AMP activated protein kinase (AMPK)-dependent pathway.

Methods: In vivo and in vitro effects of APS on glucose homeostasis were examined in a type 2 diabetes mellitus (T2DM) rat model. The T2DM rat model was duplicated by a high-fat diet (58% fat, 25.6% carbohydrate, and 16.4% protein) and a small dose of streptozotocin (STZ, 25 mg/kg, ip). After APS therapy (700 mg.kg(-1).d(-1), ig) for 8 weeks, blood glucose, glycosylated hemoglobin, and serum insulin were measured. Insulin sensitivity was evaluated by the comprehensive analysis of oral glucose tolerance tests (OGTT) and HOMA IR index. Hepatic glycogen was observed by the PAS staining method. The expression and activity of skeletal muscle AMPKalpha and acetyl-CoA carboxylase (ACC), and the phosphorylation of hepatic glycogen synthase (GS), the glycogen synthase (GS),were measured by Western blotting. Glucose uptake was measured with the 2-deoxy-[(3)H]-D-glucose method in C2C12 cells.

Results: The hyperglycemia status, insulin sensitivity, glucose uptake, and activation level of AMPK in diabetic rats were improved in response to APS administration. APS could also alleviate glucose toxicity in cultured mouse cells by the activation of AMPK.

Conclusion: APS can alleviate glucose toxicity by increasing liver glycogen synthesis and skeletal muscle glucose translocation in the T2DM rat model, via activation of AMPK.

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Related in: MedlinePlus

Effect of APS on the high glucose (HG)-treated C2C12 cell model. Analysis of the expression of protein of P-AMPKα by Western immunoblotting and glucose uptake by 2-deoxy-[3H]-D-glucose method. (A) Effect of APS on the expression of P-AMPKα of high glucose-treated C2C12 cell model (n=3). (B) Effect of APS on the glucose uptake of high glucose-treated C2C12 cell model (n=4). All data are expressed by mean±SEM. bP<0.05 vs DMSO group; eP<0.05 vs HG group, hP<0.05 vs HG+APS group.
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fig7: Effect of APS on the high glucose (HG)-treated C2C12 cell model. Analysis of the expression of protein of P-AMPKα by Western immunoblotting and glucose uptake by 2-deoxy-[3H]-D-glucose method. (A) Effect of APS on the expression of P-AMPKα of high glucose-treated C2C12 cell model (n=3). (B) Effect of APS on the glucose uptake of high glucose-treated C2C12 cell model (n=4). All data are expressed by mean±SEM. bP<0.05 vs DMSO group; eP<0.05 vs HG group, hP<0.05 vs HG+APS group.

Mentions: High glucose treatment (HG, 30 mmol/L) of C2C12 cells induced a reduction in AMPK activity. Treatment with APS increased AMPK activity in the HG cell group (Figure 7A). APS also increased glucose uptake into the HG cell group. However, this effect could be suppressed by the AMPK inhibitor, Compound C (Figure 7B).


Astragalus polysaccharides alleviates glucose toxicity and restores glucose homeostasis in diabetic states via activation of AMPK.

Zou F, Mao XQ, Wang N, Liu J, Ou-Yang JP - Acta Pharmacol. Sin. (2009)

Effect of APS on the high glucose (HG)-treated C2C12 cell model. Analysis of the expression of protein of P-AMPKα by Western immunoblotting and glucose uptake by 2-deoxy-[3H]-D-glucose method. (A) Effect of APS on the expression of P-AMPKα of high glucose-treated C2C12 cell model (n=3). (B) Effect of APS on the glucose uptake of high glucose-treated C2C12 cell model (n=4). All data are expressed by mean±SEM. bP<0.05 vs DMSO group; eP<0.05 vs HG group, hP<0.05 vs HG+APS group.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4007496&req=5

fig7: Effect of APS on the high glucose (HG)-treated C2C12 cell model. Analysis of the expression of protein of P-AMPKα by Western immunoblotting and glucose uptake by 2-deoxy-[3H]-D-glucose method. (A) Effect of APS on the expression of P-AMPKα of high glucose-treated C2C12 cell model (n=3). (B) Effect of APS on the glucose uptake of high glucose-treated C2C12 cell model (n=4). All data are expressed by mean±SEM. bP<0.05 vs DMSO group; eP<0.05 vs HG group, hP<0.05 vs HG+APS group.
Mentions: High glucose treatment (HG, 30 mmol/L) of C2C12 cells induced a reduction in AMPK activity. Treatment with APS increased AMPK activity in the HG cell group (Figure 7A). APS also increased glucose uptake into the HG cell group. However, this effect could be suppressed by the AMPK inhibitor, Compound C (Figure 7B).

Bottom Line: The hyperglycemia status, insulin sensitivity, glucose uptake, and activation level of AMPK in diabetic rats were improved in response to APS administration.APS could also alleviate glucose toxicity in cultured mouse cells by the activation of AMPK.APS can alleviate glucose toxicity by increasing liver glycogen synthesis and skeletal muscle glucose translocation in the T2DM rat model, via activation of AMPK.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathophysiology, Medical College of Wuhan University, Wuhan, China.

ABSTRACT

Aim: To establish the mechanism underlying the improvement of glucose toxicity by Astragalus polysaccharide (APS), which occurred via an AMP activated protein kinase (AMPK)-dependent pathway.

Methods: In vivo and in vitro effects of APS on glucose homeostasis were examined in a type 2 diabetes mellitus (T2DM) rat model. The T2DM rat model was duplicated by a high-fat diet (58% fat, 25.6% carbohydrate, and 16.4% protein) and a small dose of streptozotocin (STZ, 25 mg/kg, ip). After APS therapy (700 mg.kg(-1).d(-1), ig) for 8 weeks, blood glucose, glycosylated hemoglobin, and serum insulin were measured. Insulin sensitivity was evaluated by the comprehensive analysis of oral glucose tolerance tests (OGTT) and HOMA IR index. Hepatic glycogen was observed by the PAS staining method. The expression and activity of skeletal muscle AMPKalpha and acetyl-CoA carboxylase (ACC), and the phosphorylation of hepatic glycogen synthase (GS), the glycogen synthase (GS),were measured by Western blotting. Glucose uptake was measured with the 2-deoxy-[(3)H]-D-glucose method in C2C12 cells.

Results: The hyperglycemia status, insulin sensitivity, glucose uptake, and activation level of AMPK in diabetic rats were improved in response to APS administration. APS could also alleviate glucose toxicity in cultured mouse cells by the activation of AMPK.

Conclusion: APS can alleviate glucose toxicity by increasing liver glycogen synthesis and skeletal muscle glucose translocation in the T2DM rat model, via activation of AMPK.

Show MeSH
Related in: MedlinePlus