ABSTRACTS: Poster Session Abstracts
P0564 BLACK TEA INHIBITS ETEC K88+ AND ENTEROTOXIN-INDUCED FLUID LOSS IN SMALL INTESTINAL SEGMENTS OF ANAESTHETISED PIGLETS
Bruins, M. J.1; Van der Meulen, J.2; Van Amelsvoort, J. M. M.1; Van Klinken, B.1
1Unilever Health Institute, Unilever Research and Development Vlaardingen, Vlaardingen,2Institute for Animal Science and Health, ID-Lelystad, Lelystad, Netherlands
Submitted by: [email protected]
Introduction: Evidence for the anti-diarrhoeal property of tea is mainly anecdotal. Tea has the capacity to inhibit pathogen growth and toxicity of enterotoxins (1). We, therefore, studied the effect of black tea on ETEC K88+ growth, Forskolin-induced intestinal Cl- secretion and ETEC K88+ and heat-labile enterotoxin (LT)-induced intestinal fluid loss.
Methods: To test the anti-bacterial capacity of black tea, ETEC K88+ overnight cultures were harvested at the exponential phase and diluted in AOAC broth to ~103 cells/mL and incubated with black tea extract during 24 h at 37°C. Samples were taken hourly and optical density measured as an indication of bacterial growth. The capacity of black tea to inhibit Forskolin-induced Cl−secretion was tested on rat intestinal mucosa mounted in Ussing chambers by measuring the change in short-circuit current (DeltaISC) over 3 h. To test the anti-diarrhoeal capacity of tea, isotonic and equiosmolar solutions of black tea-leaf extract were perfused (8 mL/h) into ETEC K88+ or LT-infected small intestinal segments of ETEC K88+ receptor-positive anaesthetized piglets. After 8-h perfusion, changes in net fluid and electrolyte absorption were determined per cm2 gut surface area. Significances were tested by ANOVA and set at P<0.05.
Results: Black tea significantly extended the lag phase of ETEC K88+ in vitro. When rat intestinal tissue was pre-incubated with black tea the Forskolin-induced increase in DeltaISC or Cl− flux was significantly inhibited (from 4.97±0.56 to 2.01±0.19 muEq h−1 cm−2). In piglet intestinal segments, ETEC significantly reduced the net fluid absorption from 494±112 muL/cm2 (control segments) to 171±112 muL/cm2. Black tea perfusion significantly counteracted (56%) this reduction in net fluid absorption to 352±112 muL/cm2 and also improved the reduced net Na+ and Cl− absorption (data not shown). Infection of intestinal segments with LT resulted in a small but significant reduced net fluid absorption (from 494 to 322 muL/cm2) as well as reduced Na+ and Cl− absorption (data not shown) which were all significantly compensated by black tea perfusion.
Conclusion: Consuming black tea may be beneficial in treating ETEC K88+ diarrhoea. Black tea probably not only acts against pathogen growth or adhesion, but also against labile enterotoxin induced fluid secretion.
© 2004 Lippincott Williams & Wilkins, Inc.
CJ Dufresne: J Nutr Biochem 2001 Jul;12(7):404–421