Antioxidant Activities of Isoflavones and Their Biological Metabolites in a Liposomal System

Arora, Arti; Nair, Muraleedharan G.; Strasburg, Gale M.

doi:10.1006/abbi.1998.0783

Cited by 373 publications

(260 citation statements)

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“…40,41 Interestingly, daidzein supplementation normalized the depression of glutathione S-transferase-a3 and superoxide dismutase 2 by the HF diet, and further downregulated the expression of c-Jun N-terminal kinase and IkB kinase that is augmented by the HF diet (Table 1), which might be associated with the higher antioxidative capacity of daidzein metabolite, equol, rather than other isoflavones. 15 Besides these results, our hepatic transcript profiles showed that daidzein supplementation reduced hepatic lipid levels through the activation of ACAS and ACAD, which are involved in fatty acid b-oxidation, [42][43][44][45][46][47] and this activation was due to the upregulation of PPARa, their upstream gene. 48 Daidzein supplementation also functions as hepatic antisteatotic materials by the regulation of adipocyte metabolism.…”

Section: Discussionmentioning

confidence: 56%

“…10 In recent studies, the phytoestrogen genistein has been shown to attenuate NAFLD by the activation of hepatic fatty acid b-oxidation or the inhibition of adiposity through estrogen receptors -dependent or independent pathway. [11][12][13] However, there is very little information regarding the antisteatotic effects of daidzein, the analogue of genistein, by the regulation of hepatic de novo lipogenesis, adiposity and adipocytokines, although its metabolite, equol, has higher binding affinity to estrogen receptors 14 and anti-oxidative activity 15 than genistein.…”

Section: Introductionmentioning

confidence: 99%

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Daidzein supplementation prevents non-alcoholic fatty liver disease through alternation of hepatic gene expression profiles and adipocyte metabolism

et al. 2010

Int J Obes

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Introduction: Globally, non-alcoholic fatty liver disease (NAFLD) continues to rise and isoflavones exert antisteatotic effects by the regulation of hepatic lipogenesis/insulin resistance or adiposity/a variety of adipocytokines are related to hepatic steatosis. However, there is very little information regarding the potential effects of daidzein, the secondary abundant isoflavone, on NAFLD. Here, we have assessed the hepatic global transcription profiles, adipocytokines and adiposity in mice with high fat-induced NAFLD and their alteration by daidzein supplementation. Methods: C57BL/6J mice were fed with normal fat (16% fat of total energy), high fat (HF; 36% fat of total energy) and HF supplemented with daidzein (0.1, 0.5, 1 and 2 g per kg diet) for 12 weeks. Results: Daidzein supplementation (X0.5 g per kg diet) reduced hepatic lipid concentrations and alleviated hepatic steatosis. The hepatic microarray showed that daidzein supplementation (1 g per kg diet) downregulated carbohydrate responsive element binding protein, a determinant of de novo lipogenesis, its upstream gene liver X receptor b and its target genes encoding for lipogenic enzymes, thereby preventing hepatic steatosis and insulin resistance. These results were confirmed by lower insulin and blood glucose levels as well as homeostasis model assessment insulin resistance scores. In addition, daidzein supplementation inhibited adiposity by the upregulation of genes involved in fatty acid b-oxidation and the antiadipogeneis, and moreover augmented antisteatohepatitic leptin and adiponectin mRNA levels, whereas it reduced the mRNA or concentration of steatotic tumor necrosis factor a and ghrelin. Conclusions: These findings show that daidzein might alleviate NAFLD through the direct regulation of hepatic de novo lipogenesis and insulin signaling, and the indirect control of adiposity and adipocytokines by the alteration of adipocyte metabolism.

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Section: Discussionmentioning

confidence: 56%

Section: Introductionmentioning

confidence: 99%

Daidzein supplementation prevents non-alcoholic fatty liver disease through alternation of hepatic gene expression profiles and adipocyte metabolism

et al. 2010

Int J Obes

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“…Studies have shown that only 30% to 50% of the population is capable of producing equol from daidzein (Lampe et al, 1998;Rowland et al, 2000). Equol is superior to other isoflavones in its antioxidant activity (Arora et al, 1998), has greater affinity to the oestrogen receptors than its precursor daidzein (Setchell et al, 2002) and can bind 5a-dihydrotestosterone, thereby hindering its binding to the androgen receptor, thus altering growth and physiological hormone responses that are regulated by androgens (Lund et al, 2004). Therefore, milk with a high concentration of equol may be interesting as a dietary source of equol if the beneficiary effects of equol are confirmed.…”

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confidence: 99%

Effect of forage on the content of phyto-oestrogens in bovine milk

Andersen

Weisbjerg

Hansen-Møller

et al. 2009

Animal

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Phyto-oestrogens are believed to have a range of beneficial effects on predominant Western diseases. A few studies on phyto-oestrogens in milk exist and show that the composition can be affected by feeding. Therefore, the aim was to study how feeding of lucerne and grass/clover silages (GCSs) affects the concentration of phyto-oestrogens in bovine milk. Sixteen Danish Holstein cows were assigned to a 4 3 4 latin square design with four cows per treatment per period of 3 weeks. The four treatment diets were lucerne silage (LS), 2/3 lucerne silage and 1/3 maize silage (2/3LS), 1/3 lucerne silage and 2/3 maize silage (1/3LS) and GCS. Milk was collected at the end of each period and feed samples on day 6, 13 and 20 in each experimental period. Milk and pooled feed samples were analysed for the concentration of isoflavones, coumestans and lignans. The content of isoflavones was higher and the content of coumestrol lower in the GCS diet than in LS, 2/3LS and 1/3LS diets. For the LS, 2/3LS and 1/3LS diets, the concentration of coumestrol and secoisolariciresinol increased with the proportion of lucerne while the concentration of isoflavones was similar across the diets. The concentrations of the formononetin, daidzein and equol in the milk were significantly higher for the GCS diet than for the LS, 2/3LS and 1/3LS diets. In particular, the concentration of equol was 62-291 times higher for GCS. The concentration of coumestrol was significantly lower for the GCS diet compared to the LS, 2/3LS and 1/3LS diets. No pattern for the concentration of lignans was observed. In conclusion, a high concentration of isoflavones, particularly equol, and a low concentration of coumestrol were measured in the milk from the GCS diet. In contrast, a low concentration of isoflavones and a high concentration of coumestrol were measured in the milk from the LS, 2/3LS and 1/3LS diets. However, the concentration of phyto-oestrogens in bovine milk is low compared to food sources rich in phyto-oestrogens but the high concentration of equol could possibly be of therapeutic importance.

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“…It is well recognized that oxidative stress contributes to photobiological skin damage by UV radiation, both genetic and immunological, and that it may play a role in the development of UV radiation-induced skin cancers via either impairment (5). Oxidative radical scavenging by equol has been reported in numerous systems (6)(7)(8). Furthermore, both equol and NV-07␣ have the capacity to stimulate the solar-simulated UV radiation (SSUV) induction of metallothionein (MT) in the skin (9).…”

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confidence: 99%

Estrogen receptor signaling protects against immune suppression by UV radiation exposure

Widyarini

Domanski

Painter

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

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The phytoestrogenic isoflavonoid equol is known to protect against solar-simulated UV radiation-induced inflammation, immunosuppression, and skin carcinogenesis. The mechanism may involve antioxidant actions, because equol not only is a radical scavenger but also enhances the induction of a relevant cutaneous antioxidant, metallothionein. However, this study in female hairless mice examined whether the estrogenicity of the isoflavonoid might be responsible. Protection by topically applied equol against photoimmune suppression was found to be strongly and dosedependently inhibited by the estrogen receptor (ER) antagonist ICI 182,780. Furthermore, ICI 182,780 alone was found to significantly exacerbate immunosuppression resulting from solar-simulated UV radiation irradiation, suggesting a natural role for the ER in photoimmune protection. In support of this role, topical application of the physiological ligand 17-␤-estradiol also provided dosedependent photoimmune protection, inhibitable by ICI 182,780, that was attributed largely to the inactivation of the downstream actions of cis-urocanic acid, an important endogenous immunosuppressive photoproduct. Thus, a hitherto unrecognized function of the ER as a normal photoprotective immune regulator in the skin was revealed. The relationship between equol and cutaneous metallothionein suggests an association of the ER with this inducible antioxidant in constraining the photoimmune-suppressed state and therefore in the prevention of the facilitation of photocarcinogenesis by this immunological defect. This role for the ER may underlie important gender-specific differences in UV-responsiveness that would reflect different needs for environmental photoprotection in males and females.cis-urocanic acid ͉ equol ͉ hairless mouse ͉ ICI 182,780 ͉ steroid hormone R ecent studies in mice with topically applied isoflavonoids derived from the red clover, Trifolium pratense, have shown that these phytochemicals may protect effectively against UV radiation-induced skin damage. Particular interest has centered on equol ([S]-4Ј7-dihydroxyisoflavane), an isoflavonoid metabolite produced from the dietary isoflavone daidzein by the gut microflora in mammals. Equol has been found to protect mice not only against UV radiation-induced cutaneous inflammation, observed as the sunburn reaction, but also against photoimmune suppression, which is evident as a defective contact hypersensitivity (CHS) reaction (1). Consistent with this observation, it was found that topical application to humans of an equol-related synthetic isoflavonoid, NV-07␣, also protected against the UV radiation-induced suppression of the elicited Mantoux reaction (2). In mice it was shown that the immunoprotective mechanism of topically applied equol involved inactivation of the downstream actions of cis-urocanic acid, a major UV-induced immunosuppressive photoproduct produced in the skin (1). Because chronic photoimmune suppression is a prerequisite for the promotion of UV radiation-initiated tumors (3), and because topica...

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Antioxidant Activities of Isoflavones and Their Biological Metabolites in a Liposomal System

Cited by 373 publications

References 29 publications

Daidzein supplementation prevents non-alcoholic fatty liver disease through alternation of hepatic gene expression profiles and adipocyte metabolism

Daidzein supplementation prevents non-alcoholic fatty liver disease through alternation of hepatic gene expression profiles and adipocyte metabolism

Effect of forage on the content of phyto-oestrogens in bovine milk

Estrogen receptor signaling protects against immune suppression by UV radiation exposure

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