TY - JOUR
T1 - Effects of stevioside on glucose transport activity in insulin-sensitive and insulin-resistant rat skeletal muscle
AU - Lailerd, Narissara
AU - Saengsirisuwan, Vitoon
AU - Sloniger, Julie A.
AU - Toskulkao, Chaivat
AU - Henriksen, Erik J.
N1 - Funding Information:
Supported by a grant from the Ministry of University Affairs of Thailand to N.L., the Faculty of Graduate Studies, Mahidol University, and by a Grant-in-Aid from the Pacific Mountain Affiliate of the American Heart Association to E.J.H.
PY - 2004/1
Y1 - 2004/1
N2 - Stevioside (SVS), a natural sweetener extracted from Stevia rebaudiana, has been used as an antihyperglycemic agent. However, little is known regarding its potential action on skeletal muscle, the major site of glucose disposal. Therefore, the purpose of the present study was to determine the effect of SVS treatment on skeletal muscle glucose transport activity in both insulin-sensitive lean (Fa/-) and insulin-resistant obese (fa/fa) Zucker rats. SVS was administered (500 mg/kg body weight by gavage) 2 hours before an oral glucose tolerance test (OGTT). Whereas the glucose incremental area under the curve (IAUCglucose) was not affected by SVS in lean Zucker rats, the insulin incremental area under the curve (IAUCinsulin) and the glucose-insulin index (product of glucose and insulin lAUCs and inversely related to whole-body insulin sensitivity) were decreased (P<.05) by 42% and 45%, respectively. Interestingly, in the obese Zucker rat, SVS also reduced the IAUCinsulin by 44%, and significantly decreased the IAUCglucose (30%) and the glucose-insulin index (57%). Muscle glucose transport was assessed following in vitro SVS treatment. In lean Zucker rats, basal glucose transport in type I soleus and type IIb epitrochlearis muscles was not altered by 0.01 to 0.1 mmol/L SVS. In contrast, 0.1 mmol/L SVS enhanced insulin-stimulated (2 mU/mL) glucose transport in both epitrochlearis (15%) and soleus (48%). At 0.5 mmol/L or higher, the SVS effect was reversed. Similarly, basal glucose transport in soleus and epitrochlearis muscles in obese Zucker rats was not changed by lower doses of SVS (0.01 to 0.1 mmol/L). However, these lower doses of SVS significantly increased insulin-stimulated glucose transport in both obese epitrochlearis and soleus (15% to 20%). In conclusion, acute oral SVS increased whole-body insulin sensitivity, and low concentrations of SVS (0.01 to 0.1 mmol/L) modestly improved in vitro insulin action on skeletal muscle glucose transport in both lean and obese Zucker rats. These results indicate that one potential site of action of SVS is the skeletal muscle glucose transport system.
AB - Stevioside (SVS), a natural sweetener extracted from Stevia rebaudiana, has been used as an antihyperglycemic agent. However, little is known regarding its potential action on skeletal muscle, the major site of glucose disposal. Therefore, the purpose of the present study was to determine the effect of SVS treatment on skeletal muscle glucose transport activity in both insulin-sensitive lean (Fa/-) and insulin-resistant obese (fa/fa) Zucker rats. SVS was administered (500 mg/kg body weight by gavage) 2 hours before an oral glucose tolerance test (OGTT). Whereas the glucose incremental area under the curve (IAUCglucose) was not affected by SVS in lean Zucker rats, the insulin incremental area under the curve (IAUCinsulin) and the glucose-insulin index (product of glucose and insulin lAUCs and inversely related to whole-body insulin sensitivity) were decreased (P<.05) by 42% and 45%, respectively. Interestingly, in the obese Zucker rat, SVS also reduced the IAUCinsulin by 44%, and significantly decreased the IAUCglucose (30%) and the glucose-insulin index (57%). Muscle glucose transport was assessed following in vitro SVS treatment. In lean Zucker rats, basal glucose transport in type I soleus and type IIb epitrochlearis muscles was not altered by 0.01 to 0.1 mmol/L SVS. In contrast, 0.1 mmol/L SVS enhanced insulin-stimulated (2 mU/mL) glucose transport in both epitrochlearis (15%) and soleus (48%). At 0.5 mmol/L or higher, the SVS effect was reversed. Similarly, basal glucose transport in soleus and epitrochlearis muscles in obese Zucker rats was not changed by lower doses of SVS (0.01 to 0.1 mmol/L). However, these lower doses of SVS significantly increased insulin-stimulated glucose transport in both obese epitrochlearis and soleus (15% to 20%). In conclusion, acute oral SVS increased whole-body insulin sensitivity, and low concentrations of SVS (0.01 to 0.1 mmol/L) modestly improved in vitro insulin action on skeletal muscle glucose transport in both lean and obese Zucker rats. These results indicate that one potential site of action of SVS is the skeletal muscle glucose transport system.
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U2 - 10.1016/j.metabol.2003.07.014
DO - 10.1016/j.metabol.2003.07.014
M3 - Article
C2 - 14681850
AN - SCOPUS:0347316396
SN - 0026-0495
VL - 53
SP - 101
EP - 107
JO - Metabolism: Clinical and Experimental
JF - Metabolism: Clinical and Experimental
IS - 1
ER -