Dietary whey reduces energy intake and alters hypothalamic gene expression in obese phytoestrogen-deprived male rats

ANDREOLI M. F.; STOKER, CORA; LAZZARINO, GISELA; CANESINI, GUILLERMINA; LUQUE, ENRIQUE H; RAMOS, J. GUILLERMO

BRITISH JOURNAL OF NUTRITION

CAMBRIDGE UNIV PRESS

Lugar: Cambridge; Año: 2016 vol. 29 p. 1 - 9

0007-1145

Removing dietary phytoestrogens in adult male rats causes obesity and diabetes. As whey proteins have been reported to reduce food intake and improve glucose homeostasis we investigated whether they could attenuate susceptibility to obesity and diabetes due to phytoestrogen deprivation. To this end, 30 male Wistar rats were fed a high-phytoestrogen (HP) or a phytoestrogen-free (PF) diet for 10 weeks. Six rats from each group were sacrificed. The remaining HP animals (n=6) continued receiving the HP diet for six weeks. The remaining PF rats (n=12) were divided in two groups: one was given the PF diet and the other a variation of the PF diet plus whey protein (PF-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 oestradiol were assessed. Ten weeks of PF diet increased body weight, adiposity and energy intake, with upregulation of AGRP and downregulation of POMC. Longer treatment exacerbated these results, increased total T4 levels, reduced oestradiol levels and impaired glucose homeostasis. PF-W reduced energy intake and increased POMC expression; however, body weight and adiposity remained unchanged. PF-W could not prevent the hormonal changes or the high circulating glucose induced by phytoestrogen deprivation, but 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 in longer treatments.