Hypoglycemic and antidiabetic effect of ethanolic extract of leaves of Annona squamosa L. in experimental animals

The ethanolic extract of Annona squamosa L. (Annonaceae) leaves was administered orally at different doses to normal as well as streptozotocin (STZ)-induced diabetic rats and alloxan-induced diabetic rabbits. The dose of 350 mg/kg body weight (bw) reduced the fasting blood glucose (FBG) level by 6.0% within 1 h, whereas, the peak blood glucose at 1 h during glucose tolerance test (GTT) was reduced by 17.1% in normal rats. The same dose of ethanolic extract reduced FBG by 26.8% and improved glucose tolerance by 38.5 and 40.6% at 1 and 2 h, respectively, during GTT in alloxan-induced diabetic rabbits. In STZ-diabetic rats, a fall of 13.0% in FBG and an improvement in glucose tolerance by 37.2 and 60.6% at 1 and 2 h, respectively, was observed during GTT. The dose of 350 mg/kg bw of ethanolic extract in 10-day treatment of a group of STZ-diabetic rats produced 73.3% fall in FBG level and no sugar was observed in fasting urine. Treatment of severely-diabetic rabbits for 15 days with a dose of 350 mg/kg of extract reduce FBG by 52.7% and urine sugar by 75%. It brought about fall in the level of total cholesterol (TC) by 49.3% with increase of 30.3% in high-density lipoprotein (HDL) and decrease of 71.9 and 28.7% in low-density lipoprotein (LDL) and triglycerides (TG) levels, respectively.