COMPARISON OF THE EFFECTS OF AN AQUEOUS EXTRACT OF PHYSALIS-ALKEKENGIFRUITS AND OR VARIOUS DOSES OF 17-BETA-ESTRADIOL ON RAT ESTROUS-CYCLEAND UTERINE GLUCOSE-6-PHOSPHATE-DEHYDROGENASE ACTIVITY/

Intraperitoneal injections of an aqueous extract of winter cherry frui ts (Physalis alkekengi) to adult normal cycling female rats produced 1 00% diestrus and diminished uterine glucose 6-P dehydrogenase activity (an estrogen-induced protein) by 52%. Daily doses of 1.88, 3.75 and 7 .5 mu g 17-beta-estradiol administered intraperitoneally to adult fema le rats for a period of 6-8 days prolonged proestrus or estrus and inc reased uterine glucose 6-P dehydrogenase activity by 11.5%, 26.9% and 82.1%, respectively. Combined intraperitoneal injections of a given do se of the aqueous extract together with the above doses of 17-beta-est radiol for 8 consecutive days shortened the time spent in diestrus pro portional to the dose employed and proportionately reduced the uterine glucose 6-P dehydrogenase inhibitory power of the aqueous extract (1. 88 mu g estradiol, 33.9% inhibition; 3.75 mu g estradiol, 27% inhibiti on; and 7.5 mu g estradiol, 6.0% activation). The data obtained clearl y demonstrate the presence of an estrogen antagonist in the aqueous ex tract of Physalis alkekengi fruits.