QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Andlauer, W. Articles by Fürst, P. Search for Related Content PubMed PubMed Citation Articles by Andlauer, W. Articles by Fürst, P.

---

Articles

Isoflavones from Tofu Are Absorbed and Metabolized in the Isolated Rat Small Intestine

Institute for Biological Chemistry and Nutrition, University of Hohenheim, D-70593 Stuttgart, Germany

¹To whom correspondence should be addressed. E-mail: >andlauer@uni-hohenheim.de" locator-type="email">locator-type="email">andlauer@uni-hohenheim.de locator="" locator-type="email">

Studies suggest a variety of biological effects of soybean isoflavones, but there is little information regarding small intestinal absorption and metabolism. The aim of this study was to investigate intestinal handling of luminally administered soybean-based tofu in an isolated preparation of the luminally and vascularly perfused rat small intestine (male Sprague-Dawley, 45 d old). A synthetic emulsion free from blood components was used as vascular medium, with a perfluorocarbon as oxygen carrier. Luminal media consisted of tofu, predigested with pepsin and pancreatin and emulsified with bile acids, containing 39.5 µmol/L genistein compounds and 19.1 µmol/L daidzein compounds. Viability of the organ preparation was maintained during the entire perfusion, confirmed by lack of significant differences between tofu and control perfusion experiments for arterial pressure, glucose consumption, oxygen uptake, lactate-pyruvate ratio and acid-base homeostasis. Daidzein (8.9%) and genistein (8.0%) compounds from tofu exhibited almost the same (P > 0.05) absorption rate during small intestinal passage. The majority of the absorbed genistin appeared vascularly as genistein (4.4%), in addition to minor amounts of unchanged genistin (2.1%) and genistein glucuronide (1.5%). In the luminal effluent, a considerable increase of genistein (338%) as well as daidzein (190%) as cleavage products of the glucosides and malonyl-glucosides was observed. The distribution of daidzein compounds in the small intestine was not different from that of genistein compounds (P > 0.05), except for the blood vessels, which had extremely low total amounts. Sulfate derivatives of genistein and daidzein compounds were not detectable. An effect of tofu ingredients was observed on absorption rate of genistin, on glucuronidation and on distribution of genistein glucuronide in the intestine.

KEY WORDS: • intestinal absorption • intestinal metabolism • tofu • isoflavone • rats

This article has been cited by other articles:

				K. R Walsh, S. J Haak, T. Bohn, Q. Tian, S. J Schwartz, and M. L Failla Isoflavonoid glucosides are deconjugated and absorbed in the small intestine of human subjects with ileostomies Am. J. Clinical Nutrition, April 1, 2007; 85(4): 1050 - 1056. [Abstract] [Full Text] [PDF]

				S. W. J. Wang, J. Chen, X. Jia, V. H. Tam, and M. Hu Disposition of Flavonoids via Enteric Recycling: Structural Effects and Lack of Correlations between in Vitro and in Situ Metabolic Properties Drug Metab. Dispos., November 1, 2006; 34(11): 1837 - 1848. [Abstract] [Full Text] [PDF]

				E. J. Jeong, Y. Liu, H. Lin, and M. Hu SPECIES- AND DISPOSITION MODEL-DEPENDENT METABOLISM OF RALOXIFENE IN GUT AND LIVER: ROLE OF UGT1A10 Drug Metab. Dispos., June 1, 2005; 33(6): 785 - 794. [Abstract] [Full Text] [PDF]

				M. Hu, J. Chen, and H. Lin Metabolism of Flavonoids via Enteric Recycling: Mechanistic Studies of Disposition of Apigenin in the Caco-2 Cell Culture Model J. Pharmacol. Exp. Ther., October 1, 2003; 307(1): 314 - 321. [Abstract] [Full Text] [PDF]

				J. Chen, H. Lin, and M. Hu Metabolism of Flavonoids via Enteric Recycling: Role of Intestinal Disposition J. Pharmacol. Exp. Ther., March 1, 2003; 304(3): 1228 - 1235. [Abstract] [Full Text] [PDF]

				K. D. Setchell, N. M Brown, L. Zimmer-Nechemias, W. T Brashear, B. E Wolfe, A. S Kirschner, and J. E Heubi Evidence for lack of absorption of soy isoflavone glycosides in humans, supporting the crucial role of intestinal metabolism for bioavailability Am. J. Clinical Nutrition, August 1, 2002; 76(2): 447 - 453. [Abstract] [Full Text] [PDF]

				Y. Liu and M. Hu Absorption and Metabolism of Flavonoids in the Caco-2 Cell Culture Model and a Perused Rat Intestinal Model Drug Metab. Dispos., April 1, 2002; 30(4): 370 - 377. [Abstract] [Full Text] [PDF]

				C. D. Allred, Y. H. Ju, K. F. Allred, J. Chang, and W. G. Helferich Dietary genistin stimulates growth of estrogen-dependent breast cancer tumors similar to that observed with genistein Carcinogenesis, October 1, 2001; 22(10): 1667 - 1673. [Abstract] [Full Text] [PDF]