Lignans and flavonoids inhibit aromatase enzyme in human preadipocytes

Wang, Chuanfeng; Mäkelä, Taru; Hase, Tapio; Adlercreutz, Herman; Kurzer, Mindy S.

doi:10.1016/0960-0760(94)90030-2

Cited by 290 publications

(147 citation statements)

References 38 publications

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“…Additionally, we have previously observed a similar pattern of circulating testosterone reduction in animals on the Phyto-600 diet (at approximately 40-50% of Phytofree values) in three independent studies under the same experimental conditions, representing an n of 39 rats per treatment group. Another possible explanation for this finding is that phytoestrogens have the ability to inhibit the aromatase enzyme in peripheral tissues (Kellis & Vickery 1984, Ibrahim & Abul-Hajj 1990, Wang et al 1994) and the apparent protection phytoestrogens have against BPH and PCa may be via the reduction in local estrogen formation since estrogenic agents are known to be mitogenic (vom Saal et al 1997, Griffiths et al 1998, Farnsworth 1999, Shibata et al 2000, Yaono et al 2000.…”

Section: Discussionmentioning

confidence: 99%

Dietary soy-phytoestrogens decrease testosterone levels and prostate weight without altering LH, prostate 5alpha-reductase or testicular steroidogenic acute regulatory peptide levels in adult male Sprague-Dawley rats

Weber

Setchell²,

Stocco³

et al. 2001

Journal of Endocrinology

191

135

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Nutritional factors, especially phytoestrogens, have been extensively studied for their potential beneficial effects against hormone-dependent and age-related diseases. The present study describes the short-term effects of dietary phytoestrogens on regulatory behaviors (food/water intake, locomotor activity and body weight), prostate weight, prostate 5 -reductase enzyme activity, reproductive hormone levels, and testicular steroidogenic acute regulatory peptide (StAR) levels in adult Sprague-Dawley rats.Animals were fed either a phytoestrogen-rich diet containing ]600 µg/g isoflavones (as determined by HPLC) or a phytoestrogen-free diet. After 5 weeks of consuming these diets, plasma phytoestrogen levels were 35 times higher in animals fed the phytoestrogen-rich vs phytoestrogen-free diets. Body and prostate weights were significantly decreased in animals fed the phytoestrogenrich diet vs the phytoestrogen-free fed animals; however, no significant change in prostate 5 -reductase enzyme activity was observed between the treatment groups. Locomotor activity levels were higher in the phytoestrogen-rich vs the phytoestrogen-free animals during the course of the treatment interval. Plasma testosterone and androstenedione levels were significantly lower in the animals fed the phytoestrogen-rich diet compared with animals fed the phytoestrogen-free diet. However, there were no significant differences in plasma LH or estradiol levels between the diet groups. Testicular StAR levels were not significantly different between the phytoestrogen-rich vs the phytoestrogen-free fed animals.These results indicated that consumption of dietary phytoestrogens resulting in very high plasma isoflavone levels over a relatively short period can significantly alter body and prostate weight and plasma androgen hormone levels without affecting gonadotropin or testicular StAR levels.The findings of this study identify the biological actions of phytoestrogens on male reproductive endocrinology and provide insights into the protective effects these estrogen mimics exert in male reproductive disorders such as benign prostatic hyperplasia and prostate cancer.

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Section: Discussionmentioning

confidence: 99%

Dietary soy-phytoestrogens decrease testosterone levels and prostate weight without altering LH, prostate 5alpha-reductase or testicular steroidogenic acute regulatory peptide levels in adult male Sprague-Dawley rats

Weber

Setchell²,

Stocco³

et al. 2001

Journal of Endocrinology

191

135

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“…Binding of type II nuclear oestrogen receptor (Adlercreutz et al, 1992;Adlercreutz, 2007) and altering oestrogen synthesis within the breast cells and extragonadal sites, such as the adipose tissue, are other possible mechanisms (Adlercreutz et al, 1993;Saarinen et al, 2007). Enterolactone has been shown to decrease local oestrogen production by inhibiting 17-hydroxysteroid dehydrogenase type I and aromatase (Wang et al, 1994;Brooks and Thompson, 2005).…”

Section: Discussionmentioning

confidence: 99%

“…Lignans have been shown to exhibit anti-carcinogenic properties (Wang et al, 1994;Prasad 2000;Bergman Jungeström et al, 2007), and it is hypothesised that exposure to high levels may be associated with a reduction in breast cancer risk. However, results from a number of studies in Western populations have been variable.…”

mentioning

confidence: 99%

Lignans and breast cancer risk in pre- and post-menopausal women: meta-analyses of observational studies

et al. 2009

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Phyto-oestrogens are plant compounds structurally similar to oestradiol, which have been proposed to have protective effects against breast cancer. The main class of phyto-oestrogens in the Western diet is lignans. Literature reports on the effect of lignans in breast cancer risk have been conflicting. We performed three separate meta-analyses to examine the relationships between (i) plant lignan intake, (ii) enterolignan exposure and (iii) blood enterolactone levels and breast cancer risk. Medline, BIOSIS and EMBASE databases were searched for publications up to 30 September 2008, and 23 studies were included in the random effects meta-analyses. Overall, there was little association between high plant lignan intake and breast cancer risk (11 studies, combined odds ratio (OR): 0.93, 95% confidence interval (95% CI): 0.83 -1.03, P ¼ 0.15), but this association was subjected to marked heterogeneity (I 2 ¼ 44%). Restricting the analysis to post-menopausal women, high levels of plant lignan intake were associated with reduced breast cancer risk (7 studies, combined OR: 0.85, 95% CI: 0.78, 0.93, Po0.001) and heterogeneity was markedly reduced (I 2 ¼ 0%). High enterolignan exposure was also associated with breast cancer (5 studies, combined OR: 0.73, 95% CI: 0.57, 0.92, P ¼ 0.009) but, again, there was marked heterogeneity (I 2 ¼ 63%). No association was found with blood enterolactone levels (combined OR: 0.82, 95% CI: 0.59 -1.14, P ¼ 0.24). In conclusion, plant lignans may be associated with a small reduction in post-menopausal breast cancer risk, but further studies are required to confirm these results. (Beral, 2003) have both been associated with increased breast cancer risk. Isoflavones and lignans are plant compounds structurally similar to 17b-oestrodiol known as phyto-oestrogens, capable of oestrogen receptor binding (Kuiper et al, 1998;Mueller et al, 2004). Isoflavones are mostly found in soybean products, which are a staple of the Asian diet, whereas lignans are the principal group of phyto-oestrogens in Western diets. Lignans are more widespread in foods than isoflavones and are present in grain cereals, vegetables, seeds, tea and coffee (Mazur, 1998a;Mazur et al, 1998b). Microflora in the colon (Setchell et al, 1981) convert plant lignans into enterolignans, which are detectable in blood and urine. Their levels have been correlated with the amount of plant lignans ingested (Nesbitt et al, 1999).In a recent meta-analysis, an inverse dose-response relationship was shown between breast cancer risk and soy-food intake in Asian, but not in Western women (Wu et al, 2008). Lignans have been shown to exhibit anti-carcinogenic properties (Wang et al, 1994;Prasad 2000;Bergman Jungeström et al, 2007), and it is hypothesised that exposure to high levels may be associated with a reduction in breast cancer risk. However, results from a number of studies in Western populations have been variable. The aim of our systematic review was to establish whether an association exists between lignan exposure and breast cancer ris...

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“…These biological parameters represent important elements in the structure/ function relationship of the genesis of the rat CNS perinatally and the morphometric and functional characteristics of hypothalamic brain areas postnatally [28,65,67,70]. It is known that phytoestrogens inhibit aromatase enzyme activity in peripheral endocrine tissue sites during postnatal development (in vitro) [2,3,49,54,56,86,118]. However, the effect of phytoestrogens on brain aromatase has not been previously examined until now.…”

Section: Brain Aromatase and Dietary Phytoestrogensmentioning

confidence: 99%