Hypoglycaemic and hypolipidaemic effects of emodin and its effect on L-type calcium channels in dyslipidaemic-diabetic rats.

1. The aim of the present study was to evaluate the hypoglycaemic and hypolipidaemic effects of 20, 40 and 80 mg/kg per day emodin and its potential effects on L-type calcium channels in dyslipidaemic-diabetic rats. 2. Dyslipidaemic-diabetic rats were induced by a single intraperitoneal injection of streptozotocin (55 mg/kg) after intragastric administration of a high-fat diet for 2 weeks. 3. Daily administration of emodin for 2 weeks resulted in a significant dose-dependent reductions in blood glucose, serum total cholesterol, triglycerides, free fatty acids and malonaldehyde (P < 0.05) in dyslipidaemic-diabetic rats compared with vehicle-treated dyslipidaemic-diabetic rats. In addition, emodin caused dose-dependent increases in plasma superoxide dismutase activity in dyslipidaemic-diabetic rats (P < 0.05). Immunofluorescent staining and reverse transcription-polymerase chain reaction showed that the expression of L-type calcium channels in the pancreas and heart was restored, to different extents, by the three doses of emodin treatment. 4. The results of the present study suggest that emodin has antidiabetic and lipid-modulating effects that involve, in part, upregulation of L-type calcium channel expression in the pancreas and heart in dyslipidaemic-diabetic rats.