Abstract:The hypoglycemic effects of white tea were investigated, using a newly developed non-insulin-dependent diabetes mellitus (NIDDM) zebrafish model.. Treatment of the NIDDM zebra fish with 50 and 100 μg/mL of aged white peony tea (AWP), decreased the level of glucose (GLU) by 29.68% and 20.51%, respectively, after 24 h. After 48 h, the GLU values decreased by 42.16% and 51.54%, respectively, and the differences were significant (P<0.05). Moreover, the GLU values in the 25, 50, and 75 μg/mL white peony tea (WP) groups decreased by 40.18%, 52.57%, and 62.11%, respectively, after 24 h of treatment, and the differences were significant (P<0.05). The effect of white tea treatment on GLU levels of insulin-dependent diabetes mellitus (IDDM) zebrafish was also investigated. In this model, the GLU values of the 20 and 30 μg/mL AWP treatment groups (24 h) decreased by 24.92% and 23.66%, respectively, and AWP treatment for 48 h decreased GLU by 54.35% and 38.38%, respectively (P<0.05). The GLU value of the 40 μg/mL WP-treated group decreased by 22.58% (P<0.05) after 24 h, and the corresponding values in the 20 μg/mL WP-treated group, after 48 h of treatment, decreased by 26.51% (P<0.05). After incubation with 30 μg/mL tea polyphenols (TP) for 48 h, the GLU value decreased by 24.53% (P<0.05). Importantly, the hypoglycemic effects of 20 μg/mL of either WP and AWP on NIDDM zebrafish were significantly better than that of 30 μg/mL of tea phenols (TP). The hypoglycemic effect of 30 μg/mL AWP on IDDM zebrafish was slightly better than that of TP, and significantly better than that of WP. Taken together, these results suggest that both white tea and TP have a significant hypoglycemic effect; however, the hypoglycemic effect of white tea was not limited to TP dependence. The identity of the specific active components in white tea warrant further research.
