Increase of insulin sensitivity in diabetic rats received die-huang-wan, a herbal mixture used in Chinese traditional medicine.
Abstract
AIM: 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.
CONCLUSION: The present study found that oral administration of die-huang-wan
increased insulin sensitivity and delayed the development of insulin resistance
in rats.
Keywords:
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.
CONCLUSION: The present study found that oral administration of die-huang-wan
increased insulin sensitivity and delayed the development of insulin resistance
in rats.