201012-1335嗯嗯呃(4)

嗯嗯呃

- 4 - 中国科技论文在线series of ethanol, and embedded in paraffin wax before sectioning. Then the paraffin sections were cut into sections (about 5 μm thickness) then dewaxed and rehydrated. The sections were then stained with H&E dye and studied using light microscope for histopathological changes, i.e., the normal numbers and volume of the islet cells, and deformation of the islet cells [11].

1.8 Statistical analysis

The data are expressed as means ±S.D. Statistical comparisons were compared by one-way analysis of variance (ANOVA).The results were considered statistically significant if the p values were 0.05 or less.

2 Results

2.1 Identification of active compound

Fraction 14.2 of ethyl acetate extract from Potentilla chinesis yielded a yellow powder. The structure of this compound was identified as trans-tiliroside (Fig. 1) based on its IR, 1H, 13C NMR, and HRMS spectra comparison with those of the reported compound in the literature [9].

Figure 1. Structure of kaempferol-3-O-β-D-(6″-E-p-coumaroyl)glucopyranoside (trans-tiliroside)

2.2 Anti-hyperglycemic effect in normal and alloxan -induced diabetic mice Fasting blood glucose level was measured in normal and experimental mice on 0, 7 and 15th days of treatment with trans-tiliroside. Alloxan treated diabetic mice showed significant increase in the levels of serum glucose when compared to normal mice. Table1 showed fasting blood glucose levels of normal healthy mice in normal range. No marked change was observed in FBG of trans-tiliroside treated normal mice. As evident from the data, trans-tiliroside leads to a continuous fall in blood glucose level during administration. The group Ⅵ(1.6 mg/kg) had lowered blood glucose profile at day 7（p <0.05）. Both have the lowering profile at day 15 (p <0.05, p <0.01) compared to the diabetic control group. Daily treatment with 0.4, 0.8 and 1.6 mg/kg of the trans-tiliroside led to fall in blood glucose levels by 22.71, 24.90 and 29.97% respectively at 15 days. The percentage reduction of blood glucose levels in metformin–treated mice was 22.82%. The anti-hyperglycemic effects of trans-tiliroside on the mean fasting serum glucose concentration in each group of treated mice appear dose-dependent manner.

Tab. 1 Effect of oral administration of trans-tiliroside on serum glucose levels in normal and alloxan -induced

diabetic mice for 15 days

Serum glucose levels (mmol/L) Group Treatment (mg/kg/p.o.)

0-Day 7th Day 15th Day I Normal control

5.22±0.51**

6.12±1.14** 5.74±1.25** Ⅱ

Normal+trans-tiliroside (0.4) 6.54±2.53** 4.93±1.09** 5.68±1.08** Ⅲ

Diabetic control 28.69±4.19△△ 27.46±2.73△△ 26.41±4.17△△ Ⅳ

Diabetic+trans-tiliroside (0.4) 29.02±5.45△△ 25.64±5.48△△ 22.43±4.01*△△ Ⅴ

Diabetic+trans-tiliroside (0.8) 28.87±5.01△△ 25.38±3.87△△ 21.68±4.66**△△ Ⅵ

Diabetic+trans-tiliroside (1.6) 29.59±3.49△△ 24.53±2.91*△△ 20.72±3.26**#△△ Ⅶ Metformin control (125) 29.80±2.22△△ 25.23±2.38△△ 23.00±3.59*△△ Values are expressed as mean ±S.E.M.of ten observations.

* p <0.05 compared with diabetic control group. ** p <0.01 compared with diabetic control group. # p <0.05 compared with diabetic+trans-tiliroside (0.4 mg/kg) group. △△p <0.01 compared with normal control group.