Increase of insulin sensitivity in diabetic rats received die-huang-wan, a herbal mixture used in Chinese traditional medicine.
OBJECTIVE
Effects on insulin sensitivity of die-huang-wan, the herbal mixture widely used to treat diabetic disorder in Chinese traditional medicine, were investigated in vivo.


METHODS
The obese Zucker rats were employed as insulin-resistant animal model. Also, insulin-resistance was induced by the repeated intraperitoneal injections of long-acting human insulin at 0.5 U/kg three times daily into adult male Wistar rats. Insulin resistance was identified using the loss of tolbutamide (10 mg/kg) or electroacupuncture (EA)-induced plasma glucose lowering action. The plasma glucose concentration was examined by glucose oxidase assay.


RESULTS
The plasma glucose-lowering action induced by tolbutamide was significantly enhanced in obese Zucker rats receiving the repeated administration of die-huang-wan at dosage of 26 mg/kg for 3 d. Furthermore, administration of die-huang-wan delayed the formation of insulin resistance in rats that were induced by the daily repeated injection of human long-acting insulin at 0.5 U/kg three times daily and identified by the loss of tolbutamide- or EA-induced hypoglycemia. In streptozotocin-induced diabetic rats, oral administration of metformin at 320 mg/kg once daily made an increase of the response to exogenous short-acting human insulin 15 d later. This is consistent with the view that metformin can increase insulin sensitivity. Similar treatment with die-huang-wan at an effective dose (26.0 mg/kg) also increased the plasma glucose lowering action of exogenous insulin at 10 d later. The effect of die-huang-wan on insulin sensitivity seems to produce more rapidly than that of metformin.


CONCLUSIONS
The present study found that oral administration of die-huang-wan increased insulin sensitivity and delayed the development of insulin resistance in rats.
Wu
Yang-Chang
YC
Graduate Institute of Natural Products, Kaohsiung Medical University, Kaohsiung City, Taiwan, China. jtcheng@mail.ncku.edu.tw
Hsu
Jen-Hao
JH
Liu
I-Min
IM
Liou
Shorong-Shii
SS
Su
Hui-Chen
HC
Cheng
Juei-Tang
JT
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism*; D003921:Diabetes Mellitus, Experimental / Q000097:blood*; D004347:Drug Interactions; D004365:Drugs, Chinese Herbal / Q000008:administration & dosage / Q000494:pharmacology*; D007004:Hypoglycemic Agents / Q000494:pharmacology; D007328:Insulin / Q000494:pharmacology*; D007333:Insulin Resistance; D008297:Male; D008687:Metformin / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D011924:Rats, Zucker
D001786:Blood Glucose; D004365:Drugs, Chinese Herbal; D007004:Hypoglycemic Agents; D007328:Insulin; C042579:Liuwei Dihuang Decoction; D008687:Metformin