Dietary whey reduces energy intake altering hypothalamic gene expression in obese phytoestrogen deprived rats

ANDREOLI MF; STOKER C; LAZZARINO GP; CANESINI G; LUQUE EH; RAMOS JG

BRITISH JOURNAL OF NUTRITION

CAMBRIDGE UNIV PRESS

Lugar: Cambridge; Año: 2016

0007-1145

Removing dietary phytoestrogens causes obesity and diabetes in adult male rats. As whey proteins were reported to reduce food intake and improve glucose homeostasis we investigated whether they could attenuate susceptibility to obesity and diabetes due to phytoestrogen withdrawal. Thirty male Wistar rats were fed a high-phytoestrogen (HP) or a low-phytoestrogen (LP) diet for 10 weeks. Six rats from each group were sacrificed. The rest of the HP animals (n=6) continued receiving HP diet for six weeks. The remaining LP rats (n=12) were divided in two groups: one group was given LP diet, and the other received a variation of LP diet containing whey protein (LP-W). Body weight, food intake and adipose tissue weights were recorded. Hypothalamic mRNA expression of orexigenic (NPY, AGRP) and anorexigenic (POMC, CART) neuropeptides was quantified by real time PCR. Serum glucose, insulin, total T4, TSH, testosterone and estradiol were assessed. 10 weeks of LP diet increased body weight, adiposity and energy intake with upregulation of AGRP and downregulation of POMC. Continuing this treatment exacerbated these results, elevated total T4, reduced estradiol levels and impaired glucose homeostasis. LP-W reduced energy intake increasing POMC expression; however body weight and adiposity remained unchanged. LP-W could not prevent the hormonal changes or the high circulating glucose induced by phytoestrogen withdrawal, however it reduced fasting insulin.These data demonstrate that although six weeks of whey administration could not prevent obesity in phytoestrogen-deprived rats, the reduction in energy intake and circulating insulin could be beneficial effects in longer treatments.