A new soy germ fermented ingredient displays estrogenic and protease inhibitor activities able to prevent irritable bowel syndrome-like symptoms in stressed female rats.
OBJECTIVE
Irritable bowel syndrome (IBS) often associated with psychological distress, is characterized by increased gut permeability and visceral sensitivity. In animals, stress increases intestinal paracellular permeability (IPP), visceral sensitivity and colonic proteolytic activity. Estradiol reduces IPP and affects visceral sensitivity in non-stressed ovariectomized rats, but whether estrogens affect stress-induced hyperpermeability and hypersensitivity in cyclic females remains unclear. We aimed to evaluate (i) the effects of a phytoestrogen-rich soy germ fermented ingredient (SG) on visceral hypersensitivity, hyperpermeability and other symptoms in stressed intact female rats, (ii) the mechanisms of action involved on the basis of both estrogenic and protease inhibitor activities of SG.


METHODS
Female rats received orally for 15-d either SG, 17β-estradiol benzoate (EB), or vehicles, with or without the estrogen receptor (ER) antagonist ICI182.780 before stress. Visceral sensitivity, IPP, faecal proteolytic activity, plasma corticosterone, rat mast cell protease II immunostaining, and occludin expression were assessed.


RESULTS
Stress increased IPP (concomitantly to a drop in occludin expression), visceral sensitivity, faecal proteolytic activity and plasma corticosterone. Similarly to EB, SG prevented the stress-induced hyperpermeability, and hypersensitivity, without changes in plasma corticosterone. SG inhibited the increase in faecal proteolytic activity, enhanced occludin expression, and reduced the colonic mast cell density. All SG effects, except decrease on faecal proteolytic activity, were blocked by ICI182.780.


CONCLUSIONS
A 2-wk oral treatment with SG prevented the stress-induced hyperpermeability and visceral hypersensitivity in cyclic rats through ER activation, and blocked the increase in colonic proteolytic activity, suggesting that SG can be promising in IBS management.
Neuro-Gastroenterology & Nutrition Group, Toxalim, UMR 1331 INRA/INPT, 180 chemin de Tournefeuille, BP 93173, 31027 Toulouse Cedex 3, France.
Lara
L
Moussa
Valérie
V
Bézirard
Christel
C
Salvador-Cartier
Valérie
V
Bacquié
Eric
E
Houdeau
Vassilia
V
Théodorou
D000818:Animals; D004195:Disease Models, Animal; D004958:Estradiol / Q000031:analogs & derivatives / Q000494:pharmacology; D020847:Estrogen Receptor Modulators / Q000494:pharmacology; D005243:Feces / Q000737:chemistry; D005260:Female; D005285:Fermentation; D000077267:Fulvestrant; D041981:Gastrointestinal Tract / Q000187:drug effects / Q000276:immunology / Q000378:metabolism / Q000503:physiopathology*; D018525:Germination; D043183:Irritable Bowel Syndrome / Q000209:etiology / Q000276:immunology / Q000503:physiopathology / Q000517:prevention & control*; D010539:Permeability; D048789:Phytoestrogens / Q000627:therapeutic use*; D011480:Protease Inhibitors / Q000627:therapeutic use*; D059748:Proteolysis / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D011960:Receptors, Estrogen / Q000037:antagonists & inhibitors / Q000378:metabolism; D012639:Seeds / Q000737:chemistry / Q000254:growth & development; D045730:Soy Foods; D013025:Glycine max / Q000737:chemistry / Q000254:growth & development; D013312:Stress, Physiological; D013315:Stress, Psychological / Q000503:physiopathology*
D020847:Estrogen Receptor Modulators; D048789:Phytoestrogens; D011480:Protease Inhibitors; D011960:Receptors, Estrogen; D000077267:Fulvestrant; D004958:Estradiol