Estrogens activation theory

It is currently accepted that the theory of pseudocycles was elaborated to account for the estrogenic activity of compounds such as bisdehydrodoisynolic acid, allenestrol and diethylstilbestrol (Figure 16.3). 

A number of foodstuffs and plant-derived products, largely from soy, are available as nonprescription items and often are touted as providing benefits similar to those from compounds with established estrogenic activity. These products may contain flavonoids such as genistein, which display estrogenic activity in laboratory tests, albeit generally much less than that of estradiol. In theory, these preparations could produce appreciable estrogenic effects, but their efficacy at relevant doses has not been established in human trials. 

Ti-awx-resveratrol is an especially important polyphenol derivative in wine from the viewpoint of anticancer effects. The chemical stracture of this compound resembles the hormone estradiol (Fig. 2.18). The substance in fact binds to estrogen receptors, it is sometimes called a phytoestrogen ( 3.24). However, resveratrol is much more important than its minor estrogen activity would make it appear. A very intensely studied— and also hotly debated—recent question is about the enhancement of the activity of an enzyme called sirtuirr Some researchers think that resveratrol increases this activity and helps preserve healthy cell functions. Some in vitro studies support this theory, but human clinical tests are still missing. Trans-... 

BZDs biotransformed by hepatic oxidation have relatively long half-lives and usually have active metabolites ( Table 12-10). Those biotransformed by glucuronide conjugation have relatively short half-lives and no active metabolites. Only a few BZDs (e.g., clonazepam) are biotransformed by nitro reduction. Although oxidized BZDs and their metabolites may be more likely to accumulate due to age, liver disease, or concomitant use of estrogens or cimetidine, clinical data substantiating this theory are incomplete. 

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