Modulation of Aromatase by Phytoestrogens

Abstract

The aromatase enzyme catalyzes the conversion of androgens to estrogens in many human tissues. Estrogens are known to stimulate cellular proliferation associated with certain cancers and protect against adverse symptoms during the peri- and postmenopausal intervals. Phytoestrogens are a group of plant derived naturally occurring compounds that have chemical structures similar to estrogen. Since phytoestrogens are known to be constituents of animal/human food sources, these compounds have received increased research attention. Phytoestrogens may contribute to decreased cancer risk by the inhibition of aromatase enzyme activity and CYP19 gene expression in human tissues. This review covers (a) the aromatase enzyme (historical descriptions on function, activity, and gene characteristics), (b) phytoestrogens in their classifications and applications to human health, and (c) a chronological coverage of aromatase activity modulated by phytoestrogens from the early 1980s to 2015. In general, phytoestrogens act as aromatase inhibitors by (a) decreasing aromatase gene expression, (b) inhibiting the aromatase enzyme itself, or (c) in some cases acting at both levels of regulation. The findings presented herein are consistent with estrogen's impact on health and phytoestrogen's potential as anticancer treatments, but well-controlled, large-scale studies are warranted to determine the effectiveness of phytoestrogens on breast cancer and age-related diseases.

Effect of Passiflora incarnata (L) extract on gonadal maturation in young tilapia (Oreochromis sp.)

“…Bioactive effects have been reported among them, such as antioxidant, anti-inflammatory, anticancer and anti-aromatase (Olthof et al, 2001;Gülçin, 2006;Kim et al, 2011;Marrassini et al, 2011;Choo et al, 2012;Lu et al, 2012;Lee et al, 2013;Shu-Yao et al, 2013). However, in vivo effects (especially anticancer and anti-aromatase), of both flavonoid rich extracts and purified extracts are still debated (Saarinen et al, 2001;Moon et al, 2006;Genoux et al, 2011;Lephart, 2015). The works by Dhawan & Sharma (2002, 2003; Dhawan (2003) and review by Dhawan et al (2004), suggest that the compound known as BZF, which is described as a trisubstituted α-naphthoflavone isolated from the methanolic extract of P. incarnata, has a strong antiaromatase activity by restoring libido decline, sperm count and fertility in male rats exposed to substances such as cannabinoids, alcohol or nicotine.…”

Polymorphism of Cytochrome P450, Superfamily19, Polypeptide 1 Gene and Related to Aromatase Enzyme Activity in Acromegaly Iraqi Patients

“…The protein result of aromatase gene has so far been found the same despite of the tissuespecific expression patterns of aromatase. The control aromatase gene expression at all levels: mRNA, protein, functional, and enzymatic activity has been considered as important not only for the treatment of breast cancer but also the critical role of aromatase enzyme [9], but as well in males, for example, in the cases of prostate cancers or gynecomastia [10]. In every pituitary tissue, there was an expression of aromatase enzyme inclusive autopsy samples and were most increased in patients with acromegaly than in another adenoma groups.…”

Ethnobotanical uses of wild taxa as galactagogues in Sicily (Italy)

“…In particular, phytoestrogens are a group of plant-derived compounds whose chemical structure is similar to animal and human estrogens [2][3][4][5][6][7][8][9][10]. They include a wide variety of secondary metabolites, i.e., hydroxybenzoic acid, hydroxycinnamic acids, anthocyanins, proanthocyanidins, flavonols, flavones, flavonones, isoflavones, stilbenes, and lignins, which are involved in protecting plants against ultraviolet radiation, aggression by pathogens, or stressrelated responses.…”

“…They include a wide variety of secondary metabolites, i.e., hydroxybenzoic acid, hydroxycinnamic acids, anthocyanins, proanthocyanidins, flavonols, flavones, flavonones, isoflavones, stilbenes, and lignins, which are involved in protecting plants against ultraviolet radiation, aggression by pathogens, or stressrelated responses. It has been reported that some terpenoids and saponins possess similar phytoestrogen effects [3][4][5]7,[11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27]. Several hundreds of these molecules are that improve poor milk secretion, e.g., cooked lettuce, watercress and wild fennel, boiled nettle tops, pasta with endive, and sesame in bread [58].…”