To evaluate the hypoglycemic effect of propolis, streptozotocin(STZ) induced diabetic rats were divided into 4 groups such as, diabetic control group, low dose of propolis(0.1 ㎖) group, medium dose of propolis(0.3 ㎖) group and high dose of propoli...
To evaluate the hypoglycemic effect of propolis, streptozotocin(STZ) induced diabetic rats were divided into 4 groups such as, diabetic control group, low dose of propolis(0.1 ㎖) group, medium dose of propolis(0.3 ㎖) group and high dose of propolis(0.9 ㎖) group and feeding propolis extracts for 30 days. After experiment, oral glucose tolerance test(oral GTT) was carried, and 16 hours fasting blood sugar levels, body weights, blood lipid levels were measured.
Finally, pancreatic histopathological study was performed. All study results were analyzed the differences between propolis extracts feeding groups and the diabetic control group.
Followings were the results therefrom:
1. The glucose tolerance test results showed that the fasting blood sugar levels were minimum values (p<0.05) in all groups and the blood sugar levels after glucose solution administration increased at 30 minutes and were the maximum value at 1 hour and decreased at 2 hours. The blood sugar level was lower as the rate of propolis feeding was higher.
2. The fasting blood sugar level drops significantly in the all propolis feeding groups(p<0.001) and the blood sugar level drop effect was in order of the feeding amount of the propolis.
3. The increasement of body weight of low dose of propolis group was similar with that of diabetic control group. The increasement of body weight was maximum in medium dose of propolis group (p<0.05) and was the second in high dose of propolis group.
4. The total cholesterol values of medium and high dose of propolis groups were higher than those of low dose of propolis group and diabetic control group. But there was negligible difference between total cholesterol values of low dose of propolis group and that of diabetic control group
The triglyceride values were lower in order of low dose of propolis group, medium dose of propolis group, high dose of propolis group as compared 106.0±24.9 ㎎/㎗ of diabetic control group
5. The pancreatic histopathological results showed that the shrunken Langerhans islets by STZ administration recovered as normal size and the damaged β-cells regenerated in propolis groups.
In conclusion, the propolis is effective to the treatment diabetes due to the reduction of the blood sugar level and the regeneration of the damaged β-cells shown in streptozotocin-induced diabetic rats. The effect for the treatment of diabetes was maximum in medium dose of propolis group (3.3 ㎎ total flavonoids).