Reducing aromatase

[Generic MALE]

G.Male comment : ending a cycle cycle with compounds that bind least strongly to the androgen receptor will stimulate the least aromatase activity. You want a lower aromatase activity when you come off a cycle because it will help lower your estrogen, reducing its effect on the pituitary allowing testosterone to rise more quickly.
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Source: Brain Res. 1998 May 11;792(2):271-6

Title of article: The effect of anabolic-androgenic steroids on aromatase activity and androgen receptor binding in the rat preoptic area.

Author: Roselli CE.

Research department: Department of Physiology and Pharmacology, Oregon Health Sciences University, Portland, OR 97201-3098, USA. [email protected]

The level of aromatase in the preoptic area of rats is transcriptionally regulated through a specific androgen-receptor mediated mechanism and can be used as a measure of central androgenic effect. Therefore, several commonly abused anabolic-androgenic steroids (AAS) were tested for their ability to induce aromatase activity in the preoptic area of castrated rats. In addition, we determined the relative binding affinities of these compounds for the androgen receptor, as well as their ability to bind androgen receptor in vivo following subcutaneous injections. All of the AAS compounds tested significantly stimulated POA aromatase activity above castrate levels. The compounds that produced the greatest stimulation of aromatase activity were those that bound most avidly to the androgen receptor in vitro (i.e., testosterone, dihydrotestosterone and nandrolone). In contrast, the 17alpha-alkylated compounds that were tested (stanozolol, danazol, methandrostenolone) modestly stimulated aromatase and were weak competitors for the androgen receptor. The subcutaneous injection of AAS compounds increased the concentrations of occupied nuclear androgen receptors in the brain, but the magnitude of effect was not related to their potency for inducing aromatase or their relative binding affinity for the androgen receptor suggesting that androgen receptor occupancy in POA is not correlated with the action of androgen on aromatase. The present results help explain the behavioral effects of AAS compounds in rats.

 

[Generic MALE]

G.Male note : white button mushrooms, like you cook with, are shown to lower aromatase (or in other words act like arimidex). Red grapes have also shown to have anti-aromatase activity.
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Source : J Nutr. 2001 Dec;131(12):3288-93.

Title of article : White button mushroom phytochemicals inhibit aromatase activity and breast cancer cell proliferation.

Authors: Grube BJ, Eng ET, Kao YC, Kwon A, Chen S.

Division of Immunology, Beckman Research Institute of the City of Hope, Duarte, CA 91010, USA.

Estrogen is a major factor in the development of breast cancer. In situ estrogen production by aromatase/estrogen synthetase in breast cancer plays a dominant role in tumor proliferation. Because natural compounds such as flavones and isoflavones have been shown to be inhibitors of aromatase, it is thought that vegetables that contain these phytochemicals can inhibit aromatase activity and suppress breast cancer cell proliferation. Heat-stable extracts were prepared from vegetables and screened for their ability to inhibit aromatase activity in a human placental microsome assay. The white button mushroom (species Agaricus bisporus) suppressed aromatase activity dose dependently. Enzyme kinetics demonstrated mixed inhibition, suggesting the presence of multiple inhibitors or more than one inhibitory mechanism. "In cell" aromatase activity and cell proliferation were measured using MCF-7aro, an aromatase-transfected breast cancer cell line. Phytochemicals in the mushroom aqueous extract inhibited aromatase activity and proliferation of MCF-7aro cells. These results suggest that diets high in mushrooms may modulate the aromatase activity and function in chemoprevention in postmenopausal women by reducing the in situ production of estrogen.