Oolong tea

black tea and dark tea were prepared from

Camellia sinensis

var.

baiye dangcong

according to their corresponding manufacturing processes

respectively. The

in vitro

inhibitory activities of the water extracts from the three tea products towards αglucosidase were investigated by Colormetry using maltose as the substrate. Black tea and dark tea showed higher inhibitory activities than oolong tea. On the other hand

the mouse Raw264.7 cells were induced into foam cells by incubation with oxidized low density lipoprotein to examine the protective effects of the three tea products. The cellular contents of total cholesterols was detected by enzymatic colorimetry．The results showed that dark tea processed the highest inhibitory activity on transformation of macrophage-to-foam cells. The inhibitory rates of dark tea

black tea and oolong tea were observed to be 73.29%

62.31% and 51.93%

respectively．