Hypoglycemic Pharmacodynamic Study Of Malus Toringoides(Rehd.)Hughes Leaves

Objective This study aimed to evaluate the hypoglycemic effect of Malus toringoides (Rehd.) Hughes and explore the potential mechanism.Methods Streptozocin (STZ) or Alloxan (ALX) induced diabetic mice were used for the study hypoglycemic effect of three different extracts (extractum, kangzhuganlu, flavonoids) from Malus toringoides (Rehd.) Hughes. After establishment of diabetic model, STZ or ALX induced diabetic mice were daily treated with extractum900mg/kg, kangzhuganlu360mg/kg, flavonoids180mg/kg, respectively. The diabetic mice were treated for4consecutive days and the blood glucose levels were tested1h after treatment. Body weight was determined by every other day. This experiment was conducted3times. In the third experiment, the masses of liver, spleen, thymus, and the serum insulin and c-peptide were assessed on the fourth day after blood glucose detection.STZ or ALX induced diabetic mice and STZ induced diabetic rats were used for the study hypoglycemic effect of flavonoids. The methods of model establishment, administration, weighing were the same like above.72h after establishment of diabetic model, STZ or ALX induced diabetic mice and STZ-induced diabetic rats were daily treated with flavonoids at doses of45,90,180mg/kg and37.5,75,150mg/kg, respectively. The experiment about diabetic mice was conducted3times. For STZ-induced rats, hemoglobin (Hb), glycosylated hemoglobin (Ghb), serum insulin and c-peptide, hepatic glycogen, superoxide dismutase (SOD) activity and malondialdehyde (MDA) level in liver were assessed on the fourth day after blood glucose detection.Results Compared with the model group, the blood glucose levels of diabetic mice treated with three different extracts were reduced. The treatment of extracts can not improve the reduction of body weight. The masses of liver were decreased in extractum, kangzhuganlu treated mice. Significant increase in serum insulin and c-peptide were detected in diabetic mice treated with extractum; the increase in serum insulin and c-peptide were detected in ALX induced diabetic mice treated with kangzhuganlu; the increase in serum insulin was detected in STZ induced diabetic mice treated with flavonoids.Compared with the model group, the blood glucose levels of diabetic mice and rats treated with flavonoids were reduced. Significant decrease in Ghb level was observed in treated rats compared with diabetic rats. Significant increase in Hb, serum insulin, c-peptide were detected in flavonoids-treated rats. The treatment also significantly elevated SOD activity and reduced MDA level in the liver of diabetic rats. Besides, the treatment of flavonoids can neither attenuate the reduction of body weight nor improve the masses of liver, spleen, thymus.Conclusions The findings of this study suggest that extracts from the Malus toringoides (Rehd.) Hughes leaves may possess an antidiabetic activity in animals with established diabetes. The potential antidiabetic mechanism of flavonoids may be related to antioxidant effects and protect the pancreas.