Modification of Carcinogen Metabolism by Indolylic Autolysis Products of Brassica Oleraceae

“…In human volunteers the rate of 2-hydroxylation of oestradiol in an in vivo radiometric assay was increased by 50 YO after daily exposure to 6-7 mg indole-3-carbinol/kg for 7 d and the urinary excretion of 2-hydroxyoestrone was increased relative to that of oestriol (Michnovicz & Bradlow, 1990, 199 1). Indole-3-carbinol forms condensation products under acid conditions ; the ability of these products to induce similar effects to indole-3-carbinol and the inactivity of the parent compound when administered intraperitoneally has led to the suggestion that the condensation products formed in the acid milieu of the stomach might be the active moieties in this induction (Bradfield & Bjeldanes, 1991).…”

Section: Oestrogen Metabolismmentioning

confidence: 99%

“…Many of the substances that we have described as potential anticarcinogens have also been shown to possess potentially hazardous properties. For example, indole-3-carbinol has been shown to promote carcinogenesis in certain models (Pence et al 1986;Bailey et al 1987) and its toxicology will need to be thoroughly studied before an increase in its consumption can be recommended (Bradfield & Bjeldanes, 1991). Other examples of mutagenic, clastogenic, carcinogenic and cocarcinogenic effects of dietary constituents previously referred to are given in Table 1.…”

Section: A New Class Of Nutrients?mentioning

confidence: 99%

Anticarcinogenic Factors in Plant Foods: A New Class of Nutrients?

1994

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“…(iso)thiocyanates and indoles (3). A possible mechanism of action of these constituents may be the induction of gastrointestinal detoxi fication enzymes (4)(5)(6)(7)(8)(9). Important drug metabolizing or detoxi fication enzymes are glutathione S-transferases (GST*; EC 2.5.1.18), a family of isozymes divided into three main classes, a, 7T and ]i (10)(11)(12).…”

Section: Introductionmentioning

confidence: 99%

Effects of consumption of Brussels sprouts on intestinal and lymphocytic glutathione S-transferases in humans

et al. 1995

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A high intake of glucosinolate-containing cruciferous vege tables, such as Brussels sprouts (Brassica oleraceae), has been linked to a decreased cancer risk, but the underlying mechanism is still unclear. The aim of this study was to reveal possible modulating effects of consumption of Brussels sprouts on duodenal, rectal and lymphocytic (i) glutathione S-transferase (GST) enzyme activity, (ii) GST isozyme levels and (iii) glutathione (GSH) content. Ten healthy non-smoking volunteers were randomly assigned to two groups in a cross-over design. Five persons started on a glucosinolate-free diet (control period), while the other five consumed 300 g/day cooked Brussels sprouts, at the expense of 300 g glucosinolate-free vegetables (sprouts period). After 7 days the regimen was changed for a further week. At the end of both periods blood samples and duodenal and rectal biopsies were taken. Mean GST activity showed marked differences between duodenal, rectal and lymphocytic cytosols (737 ± 54, 321 ± 29 and 154 ± 14 nmol/min/mg protein respectively), but was uninfluenced by the dietary regimen. Isozyme distribution varied greatly between the tissues. In duodenum GST-a, -7C and -[i iso zymes were expressed in considerable amounts (8441 ± 1365,3002 ± 223 and 536 ± 248 ng/mg protein respectively). Rectal biopsies also contained above three GST classes, but here GST-n was the most pronounced expressed isozyme (2849 ± 246) followed by GST-|n (495 ± 242), while GSTa was only present in minor quantities (149 ± 31). In lymphocytes only GST-71; (755 ± 96) and GST-p, (83 ± 54) could be detected. As a result of the dietary regimen rectal GST-a and -71 levels were slightly increased at the end of the sprouts period, by 30 and 15% respectively. GSH contents were uninfluenced by the dietary regimen. In conclusion, consumption of glucosinolate-containing Brussels sprouts for 1 week results in increased rectal GST-a and -tc isozyme levels. We hypothesize that these enhanced detoxification enzyme levels may partly explain the epidemiological association between a high intake of glucosinolates (cruciferous vegetables) and a decreased risk of colorectal cancer.

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Modification of Carcinogen Metabolism by Indolylic Autolysis Products of Brassica Oleraceae

Cited by 39 publications

References 31 publications

Effect of Dietary Cabbage Fermentation Extract and Young Barley Leaf Powder on Immune Function of Sprague-Dawley Rats.

Effect of Dietary Cabbage Fermentation Extract and Young Barley Leaf Powder on Immune Function of Sprague-Dawley Rats.

Anticarcinogenic Factors in Plant Foods: A New Class of Nutrients?

Effects of consumption of Brussels sprouts on intestinal and lymphocytic glutathione S-transferases in humans

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