Erratum to: Phase II metabolism of the soy isoflavones genistein and daidzein in humans, rats and mice: a cross-species and sex comparison

Abstract

Unfortunately, in lines 12 and 16 of the abstract section, the chemical compound names of the major phase II metabolites of daidzein and genistein were incorrectly published as 7-sulfo-4′-glucuronides. The correct names are 4′-sulfo-7-glucuronides.The online version of the original article can be found under

Effects of isoflavones on breast tissue and the thyroid hormone system in humans: a comprehensive safety evaluation

“…Various isoflavones are metabolised in different ways. The biotransformation of daidzein and genistein is well documented (Mortensen et al 2009 ; Rafii 2015 ; Soukup et al 2016a , b ; Yang et al 2012 ). It is noteworthy that substantial differences in the phase II and microbial metabolism were reported for these two soy isoflavones (Soukup et al 2016a , b ).…”

“…A comprehensive comparison of the phase I/II and microbial metabolism of daidzein and genistein in adult humans, rats, and mice revealed considerable differences between the investigated species (Hosoda et al 2011 ; Soukup et al 2014 , 2016a , b ). Considering the phase II metabolism, the 4′-sulfo-7-glucuronides (39–49%) and in case of genistein also the diglucuronide (34% of the measured genistein and genistein phase II metabolites) were reported to be the major metabolites in human plasma (Hosoda et al 2011 ; Soukup et al 2014 , 2016a , b ). In mice, monoglucuronides (30–40%) and monosulfates (33–41%) of daidzein and genistein predominated.…”

“…In mice, monoglucuronides (30–40%) and monosulfates (33–41%) of daidzein and genistein predominated. In addition, sex-specific differences were observed in rats (Soukup et al 2016a , b ). In male rats, the major conjugates were the disulfates (23–62%) and 4′-sulfo-7-glucuronides (19–54%), whereas in females, mainly, 7-glucuronides were observed.…”

“…The aglycones are of particular interest, since they are regarded as the biologically most active form (see “ Mechanistic background ”). The amount of aglycones in plasma was low in humans (0.5–1.3%) and rats (0.5–3.1%), but comparatively high in mice (3.1–26.0%), particularly for daidzein (Soukup et al 2016a , b ). These findings point to the difficulties in transferring the results obtained in animal experiments to the human situation.…”

“…2 ). In contrast, rats and mice were reported to be 100% equol producers (Soukup et al 2016a , b ). The highly variable formation of microbial metabolites in humans might lead to substantial differences with respect to biological effects, in particular estrogenic and anti-thyroidal activities as reported in in vitro studies.…”