3.2. BG-lowering effects of PCEs in diabetic mice: The BG concentrations of the diabetic mice decreased to different extents before and 7 hours and 11 hours after intraperitoneal injection of 200 mg/kg BW of PCE-A, PCE-B, PCE-C and PCE-D (Table 2). These results indicated that PCE-A and PCE-B had significant effects on reducing the BG levels of normal mice from 5.77 ± 1.02mM to 3.88 ± 0.48mM ( p < 0.01) and from 5.88 ± 0.72 mM to 3.98 ± 0.78 mM ( p < 0.01), respectively.
However, there was no significant difference in BG levels before and after PCE-A and PCE-B treatment in the alloxan-diabetic mice group. The BG levels in the normal and alloxan-diabetic mice treated with PCE-D showed no significant difference ( p > 0.05), indicating that PCE-D does not have any BG-lowering effect on the tested mice. PCE-C showed a BG-lowering effect on normal mice. The BG level decreased significantly ( p < 0.05) from 5.39 ± 0.75mM before PCE-C treatment to 4.40 ± 0.84 mM 7 hours after PCE-C injection. However, no significant decrease was observed 11
hours after PCE-C treatment. For alloxan-diabetic mice, PCE-C treatment resulted in a significant decrease ( p < 0.001) in BG level from 15.32 ± 4.38 mM before PCE-C injection to 5.77 ± 1.46 mM 7 hours after PCE-C treatment. The hypoglycemic effect of PCE-C may not be due to the stimulation of insulin secretion but by other pathways.