Hypoglycemic Effects of Tea Extracts and Sterols from Momordica charantia

Mice administered with different doses of infusion obtained from commercial tea preparations of Momordica charantia fruit and leaf displayed variable hypoglycemic activity. M. charantia fruit tea extract at 100 mg/kg BW had demonstrated significant (P=0.001) blood glucose lowering during 0.5h to 1.0h observation period, while M. charantia leaf tea extract was most effective at 100 mg/kg BW with sustained blood glucose reduction pattern starting at 1.5h to 2.5h. The dichloromethane extract of the freeze-dried fruit of M. charantia afforded a mixture of clerosterol (1a) and 5α-stigmasta-7-en-3β-ol (1b) in a 2:1 ratio by silica gel chromatography. A single intraperitonial injection of 10 mg/kg BW of a mixture of 1a and 1b in normoglycemic mice significantly (P<0.05) reduced the blood glucose level with distinct percent blood glucose reduction from 1.5h to 2.0h compared with the negative control.