Hypoglycemic pathways of terpenes from Cornus officinalis / 中国药理学通报

ABSTRACT

Aim To investigate the hypoglycemic pathway of terpenes from Cornus officinalis(TCF) from three aspects of insulin dependence, α-glucosidase inhibition, insulin sensitizing.Methods Insulin-deficient diabetes mellitus(DM) model was induced by tail vein injection of streptozotocin(STZ) into SD rats at the dose of 50mg·kg-1 body weight.Rats were randomly divided into seven groups: control group(CON), model group(Model), metformin group(Met) 0.1g·kg-1, shenqi jiangtang granules(Shenqi) group 1.0 g·kg-1, three dose groups of TCF: 0.10, 0.05, 0.025 g·kg-1.Body weight and blood glucose were measured every week.After four weeks, glycosylated hemoglobin (HbA1c), glycosylated serum protein (GSP) were determined.Normal ICR mice were divided into seven groups: CON, Model, Met group 0.2g·kg-1, acarbose group(Acar) 0.1 g·kg-1, Shenqi group 1.5g·kg-1, three dose groups of TCF: 0.20g·kg-1;0.10g·kg-1;0.05 g·kg-1.After 10 days of administration, intraperitoneal injections of glucose and gavage starch tolerance tests were employed.Normal SD rats were divided into six groups: CON, rosiglitazone group 0.02 g·kg-1, glipizide group 0.02 g·kg-1, three dose groups of TCF: 0.10, 0.05, 0.025 g·kg-1.After seven days of administration, intraperitoneal glucose tolerance test(IPGTT) was employed and levels of insulin was determined.Results (1)High dose of TCF significantly reduced the level of HbA1c(P<0.05), GSP(P<0.05) on STZ model rats;(2)TCF significantly improved the glucose tolerance and gavage starch tolerance in ICR mice(P<0.05);(3) High dose of TCF significantly reduced the blood glucose and serum insulin level.Conclusions TCF has obvious effects on inhibiting glucose absorb and promoting the use of glucose.It is able to exert hypoglycemic effect through non-insulin dependent pathway, whereas, whether it has the effects of α-glucosidase inhibition and insulin sensitization should be further validated.