Lifelong exposure to dietary isoflavones reduces risk of obesity in ovariectomized Wistar rats.
METHODS
Traditional Asian diet rich in soy isoflavones (ISOs) is discussed to be linked to a lower obesity prevalence. In lifelong and short-term exposure scenarios we investigated effects of an ISO-rich diet on the body composition and development of obesity in female rats.


RESULTS
Female Wistar rats grew up on ISO-free or ISO-rich control diet (CON ISO: 467 mg/kg diet). Starting postnatal day 83, ovariectomized and intact animals received high calorie Western diet (WD) in the absence or presence of ISO (WD ISO: 431 mg/kg diet) for 12 weeks to induce obesity or maintained on respective control diet (CON). One group starting ISO exposure after ovariectomy mimics short-term ISO exposure in postmenopausal Western women. Lifelong but not short-term ISO exposure resulted in reduced body weight, visceral fat mass, serum leptin, and smaller adipocytes. ISO decreased hepatic SREBP-1c, ACC, FAS, and PPARγ mRNA expression in nonobese animals. Moreover, ovariectomy reduced skeletal muscle weight, which was antagonized by both short-term and lifelong ISO exposure.


CONCLUSIONS
Our results indicate that in female rats lifelong but not short-term ISO intake reduces the risk to develop obesity. Furthermore, lifelong and short-term ISO exposure may antagonize loss of skeletal muscle mass induced by ovariectomy.
Department of Molecular and Cellular Sports Medicine, Institute of Cardiovascular Research and Sports Medicine, German Sports University, Cologne, Germany.
Anne
A
Kurrat
Department of Molecular and Cellular Sports Medicine, Institute of Cardiovascular Research and Sports Medicine, German Sports University, Cologne, Germany.
Tina
T
Blei
Department of Molecular and Cellular Sports Medicine, Institute of Cardiovascular Research and Sports Medicine, German Sports University, Cologne, Germany.
Felix M
FM
Kluxen
Department of Molecular and Cellular Sports Medicine, Institute of Cardiovascular Research and Sports Medicine, German Sports University, Cologne, Germany.
Dennis R
DR
Mueller
Clinic for Cattle, Endocrinology, University of Veterinary Medicine, Hannover, Germany.
Marion
M
Piechotta
Department of Safety and Quality of Fruit and Vegetables, Max Rubner-Institut, Karlsruhe, Germany.
Sebastian T
ST
Soukup
Department of Safety and Quality of Fruit and Vegetables, Max Rubner-Institut, Karlsruhe, Germany.
Sabine E
SE
Kulling
Department of Molecular and Cellular Sports Medicine, Institute of Cardiovascular Research and Sports Medicine, German Sports University, Cologne, Germany.
Patrick
P
Diel
D017667:Adipocytes / Q000166:cytology / Q000187:drug effects; D000818:Animals; D001823:Body Composition / Q000187:drug effects; D019587:Dietary Supplements; D002149:Energy Intake / Q000187:drug effects; D005260:Female; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D007529:Isoflavones / Q000097:blood / Q000494:pharmacology*; D020738:Leptin / Q000097:blood; D009765:Obesity / Q000235:genetics / Q000378:metabolism* / Q000517:prevention & control*; D010052:Ovariectomy; D047493:PPAR alpha / Q000235:genetics; D047495:PPAR gamma / Q000235:genetics; D017208:Rats, Wistar; D013025:Glycine max / Q000737:chemistry; D051780:Sterol Regulatory Element Binding Protein 1 / Q000235:genetics; D015430:Weight Gain / Q000187:drug effects; D019014:fas Receptor / Q000235:genetics
C491898:Fas protein, rat; D007529:Isoflavones; D020738:Leptin; D047493:PPAR alpha; D047495:PPAR gamma; C497389:Srebf1 protein, rat; D051780:Sterol Regulatory Element Binding Protein 1; D019014:fas Receptor; D007334:Insulin-Like Growth Factor I
Isoflavones; Obesity; Ovariectomy; Phytoestrogens; Soy