The Hypoglycemic Mechanism Of Tea Polysaccharides In Diabetic Mice

Objective To investigate the hypoglycemic mechanism of tea polysaccharides in diabeticmice.Methods 1 Effect of tea polysaccharides on alloxan-induced hyperglycemia Male 1CR mice were randomly divided into 2 groups: the control group and the experimental group (10 mice per group) according to their weight and fasting blood glucose. The experimental group was administrated with tea polysaccharides at the dosage of 400mg/Kg bw. According to the dosage, the concentration of tea polysaccharides of 0.5ml per day for one mouse was prepared, while the control group administrated with the same volume of distilled water. 4 weeks later, the fasting blood glucose was detected. Then the mice were injected with alloxan (200mg/Kg bw) . After model-prepared with alloxan, the mice weren't administrated. The fasting blood glucose was detected after model-prepared for 3 days.2 Effect of tea polysaccharides on islet oxidative lesion induced by alloxan The waywas the same as method 1 described before. The activity of SOD and GSH-Px and the content of MDA in liver were observed.3 Effect of tea polysaccharides on blood glucose in diabetic mice After a fast of 12 hours, male ICR mice were prepared for diabetic model by ip 200mg/Kg bw alloxan. 7 days later, the mice with fasting blood glucose above 1 1.1mmol/L were chosen as diabetic mice. The diabetic mice were randomly divided into 3 groups: the negative control group, the low dosage group and the high dosage group (10 mice per group ) . The 4th group was the normal control group (8 mice) . The two groups of the low and high dosage were administrated with tea polysaccharides at the dosages of 200mg/Kg bw and 400mg/Kg bw, respectively. According to the two dosages, the two concentrations of tea polysaccharides of 0.5ml per day for one mouse were prepared, while the negative control group and the normal control group with the same volume of distilled water. The experiment lasted 6 weeks. The effect of tea polysaccharides on fasting blood glucose were determined at 0 weeks, 2 weeks, 4 weeks and 6 weeks.4 Effect of tea polysaccharides on glycometaholism in diabetic mice The way was the same as method 3 described before. The content of liver glycogen and the activity of liver glucokinase were studied.5 Effect of tea polysaccharides on repaired the lesion islets in alloxan induced diabetic mice The way was the same as method 3 described before. The islets were observed.Results 1 Effect of tea polysaccharides on alloxan-induced hyperglycemia There were no differences in fasting blood glucose between the experimental group and the control group both before and after administration (P>0.05) . After model-prepared for 3 days, the fasting blood glucose level of the experimental group was not increased compared with the control group (P<0.01) .2 Effect of tea polysaccharides on islet oxidative lesion induced by alloxan The activity of SOD and GSH-Px of the experimental group was significantly increased (P<0.01 ) and the content of MDA was significant reduced (P<0.05) compared to those of the control group.3 Effect of tea polysaccharides on blood glucose in diabetic mice Before administration there were no differences in fasting blood glucose among the negative control group, the low dosage group and the high dosage group (P>0.05) . The fasting blood glucose level of both the low dosage group and the high dosage group were reduced compared with the negative control group at 2 weeks , 4 weeks and 6 weeks (P<0.01) . At 6 weeks, there were no differences in fasting blood glucose between the high dosage group and the normal control group (P>0.05), but the fasting blood glucose level of the low dosage group was higher compared with the normal control group (P<0.05) .4 Effect of tea polysaccharides on glycometabolism in diabetic mice The contents of liver glycogen of both the low dosage group and the high dosage group were significantly increased compared to those of the negative control group (P<0.01) . The activity...