Possible Interaction: Estradiol and Melatonin

“A significant decrease of estradiol concentrations was observed after 6 months of the melatonin treatment in comparison to initial levels.”

“Both transdermal and oral estradiol treatment led to an increase as well as decrease of melatonin production in different patients.”

“Progesterone, melatonin, and serotonin enhance hyperactivation through specific membrane receptors, and 17β-estradiol suppresses this enhancement by progesterone and melatonin via a membrane estrogen receptor.”

“We suggest that 17beta-estradiol differentially affects MT1 and MT2 melatonin receptor functions, attenuates melatonin responses through activation of MT1 receptors, and increases the MT2 receptors density.”

“… melatonin , at a physiological concentration (1 nM) and in the presence of serum or estradiol: (a) inhibits, in a … cell cycle, and (c) reduces the metastasic capacity of these cells and counteracts the stimulatory effect of estradiol on cell invasiveness; this effect is … E-cadherin and beta(1)-integrin.”

“ Melatonin also counteracts the stimulatory effects of 17beta-estradiol on cell adhesion (P < 0.001).”

“The simultaneous addition of 17beta-estradiol and melatonin resulted in a significantly lower chemotactic response than that of 17beta-estradiol-treated cells (P < 0.001).”

“However, 17beta-estradiol exposure negated the ability of melatonin to inhibit proliferation.”

“ Melatonin (aMT) appears to be a potentially important oncostatic substance that can block the mitogenic effects of tumour-promoting hormones and growth factors such as oestradiol and epidermal growth factor, in vitro.”

“ Melatonin (0.1 nM-1.0 μM) treatment inhibited estradiol (1.0 nM)-induced endometrial epithelial cell proliferation at 48 hours but not 24 hours of culture.”

“Low baseline estradiol levels in our study population may have hindered the ability to detect any further estradiol-lowering effects of melatonin.”