Quality, Labeling Accuracy, and Cost Comparison of Purified Soy Isoflavonoid Products

Chua, Richard; Anderson, Kitty; Hu, Ming

doi:10.1089/acm.2004.10.1053

Cited by 25 publications

(22 citation statements)

References 12 publications

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“…Quantitative analysis of three main isofl avones (genistein, daidzein and glycitein), their glycosides as well as malonyl and acetyl derivatives was performed by using high performance liquid chromatography (HPLC) according to Chua et al (2004). At least three tablets of each product were tested separately, and standard deviation (SD) values were always lower than 1%.…”

Section: Methodsmentioning

confidence: 99%

Different amounts of isoflavones in various commercially available soy extracts in the light of gene expression‐targeted isoflavone therapy

Piotrowska

Jakóbkiewicz‐Banecka

Węgrzyn

2010

Phytotherapy Research

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Isoflavones are plant-derived, biologically active compounds that are commonly used as natural drugs or diet supplements in the treatment of menopausal symptoms and as antioxidants. Recently, it was proposed that genistein (4',5,7-trihydroxyisoflavone) may be used in the treatment of patients suffering from Sanfilippo disease (mucopolysaccharidosis type III), a severe genetic disorder for which no therapy is available. A pilot clinical study with this novel therapy, called 'gene expression-targeted isoflavone therapy' (GET IT), indicated that a standardized, genistin-rich soy isoflavone extract is effective in the treatment of such patients. Since various isoflavone-containing products are commercially available, the content of the main isoflavones were measured in such products. Extremely different amounts of isoflavones were determined in various products, from 0.13 to 39 mg per tablet. Only some of these products were found to be effective in inhibition of the synthesis of glycosaminoglycans (compounds whose degradation is severely impaired in mucopolysaccharidoses, including Sanfilippo disease) in cultured fibroblasts. Since in GET IT the dose of genistein is calculated per patient's body weight, the amount of this isoflavone in a tablet is crucial for this therapy. Therefore, the results presented in this report indicate that a careful choice of a proper isoflavone extract is necessary for GET IT.

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Section: Methodsmentioning

confidence: 99%

Different amounts of isoflavones in various commercially available soy extracts in the light of gene expression‐targeted isoflavone therapy

Piotrowska

Jakóbkiewicz‐Banecka

Węgrzyn

2010

Phytotherapy Research

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“…Therefore, concentrations of formononetin and biochanin A should be the main determinants used to compare the isoflavone content differences between products. In our previous study of soy isoflavone supplement products, we noticed a lot of peaks other than soy isoflavone's peaks in 13 products that were analyzed and classified them as impurities 13 . In our analysis of 5 red clover products and the USP red clover standard extract, peaks resulting from these impurities (i.e., peaks other than biochanin A, formononetin, genistein and daidzein) are more prevalent in the chromatograph profiles of red clover products than from the standard USP red clover extract ( Fig.…”

Section: Hplc and Uplc Profiles Of Various Red Clover Productsmentioning

confidence: 99%

“…In a previous study from our laboratory, a comparison among thirteen different retailed soy isoflavone products showed that the exact compositions of these products varied drastically from product to product 13 . Only four out of 13 products contained 90% or more of the isoflavone contents claimed on the label.…”

Section: Introductionmentioning

confidence: 99%

Variable Isoflavone Content of Red Clover Products Affects Intestinal Disposition of Biochanin A, Formononetin, Genistein, and Daidzein

Wang

Chen

Joseph

et al. 2008

The Journal of Alternative and Complementary Medicine

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Marketed red clover products use a wide variety of labels and the isoflavone contents from the lable is ambiguous. In the present study, we analyzed the content of various isoflavone products, and determined a) the content and b) how sample matrix of red clover products affects intestinal disposition of main isoflavones within it using the human intestinal Caco-2 cell model. Analysis using high and ultra-performance liquid chromatography indicates that the isoflavone content varied significantly (p<0.05) between the chosen products. Consequently, rates of isoflavone absorption across the Caco-2 cell monolayers varied (p<0.05) greatly. Unexpectedly, permeabilities of biochanin A and formononetin (two key biomarkers) were found to be significantly affected (p<0.05) by the product matrix. As expected, biochanin A was the only isoflavone with noticeable metabolite peaks in both apical and basolateral sides. Interestingly, rates of metabolism and the polarity of the glucuronidated biochanin A excretion were also significantly altered (p<0.05) by product matrix. Studies using breast cancer resistance protein inhibitor dipyridamole showed that both the apical and basolateral excretion of biochanin A glucuronides were significantly (P<0.05) reduced (7.5 and 9.4-fold, respectively) when dipyridamole is present. This provides evidence that BCRP is the main transporter responsible for the apical efflux of isoflavone glucuronides. In conclusion, the isoflavone contents of the marketed red clover products are highly variable, and product matrix significantly affected intestinal disposition of red clover isoflavones by altering their absorption rates, permeabilities, biochanin A glucuronide excretion rates, and the polarity of biochanin A glucuronide excretion. This research provides scientific evidence to support the standardization effort so that consumers can make intelligent product choices.

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“…The level of impurities was high in most of the products. Chua et al [15] found that among 13 commercially available extracts (purchased in the Washington State, USA), only 4 contained at least 90% of the isoflavone content claimed on the label. Moreover, in 2 products, impurities exceeded 40% of the total mass of the extract.…”

Section: P<005 (Values Marked With Asterisks)mentioning

confidence: 99%

Differential Effects of Various Soy Isoflavone Extracts on Bacterial Growth and Human Fibroblast Viability

A¹,

Blendowska²,

Węgrzyn³

et al. 2017

Preprint

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Abstract:Flavonoids, compounds present in many dietary supplements, affect growth of different bacterial species when tested as purified or synthetic substances. Here, we asked if soy isoflavone extracts, commonly used in many products sold as anti-menopausal dietary supplements, influence bacterial growth similarly to synthetic isoflavone, genistein. Four commercially available products were tested in amounts corresponding to genistein concentrations causing inhibition of growth of Vibrio harveyi (a model bacterium sensitive to this isoflavone) and Escherichia coli (a model bacterium resistant to genistein). Differential effects of various extracts on V. harveyi and E. coli growth, from stimulation, through no changes, to inhibition, were observed. Moreover, contrary to genistein, tested extracts caused a decrease (to different extends) in viability of human dermal fibroblasts. These results indicate that effects of various soy isoflavone extracts on bacterial growth and viability of human cells are different, despite similar declared composition of the commercially available products.

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Quality, Labeling Accuracy, and Cost Comparison of Purified Soy Isoflavonoid Products

Cited by 25 publications

References 12 publications

Different amounts of isoflavones in various commercially available soy extracts in the light of gene expression‐targeted isoflavone therapy

Different amounts of isoflavones in various commercially available soy extracts in the light of gene expression‐targeted isoflavone therapy

Variable Isoflavone Content of Red Clover Products Affects Intestinal Disposition of Biochanin A, Formononetin, Genistein, and Daidzein

Differential Effects of Various Soy Isoflavone Extracts on Bacterial Growth and Human Fibroblast Viability

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