cristina.domenech@urv.cat

Identificador:  TDX:2881

Handle: https://hdl.handle.net/20.500.11797/TDX2881

Autors:  Domenech Coca, Cristina

Resum:
Chrononutrition studies the relationship between biological rhythms and metabolism. Nowadays, it has been embraced within nutritional approaches in order to improve dietary advices and their final result. The Xenohormesis theory proposes that animals recognize bioactive compounds from plants, mainly polyphenols, as non-photic cues for checking environmental conditions, allowing them to respond in advance to environmental alterations and to improve their survival. In this framework, the main aim of the present thesis is to evaluate whether fruit consumption in or out of their natural season produce effects on different key biomarkers of seasonality and neuroendocrine processes in normoweight and cafeteria-fed obese Fischer 344 rats. We found that in healthy Fischer 344 rats, the oral consumption of red-grape, but not cherry, during its natural season characterized by a short day photoperiod produced behavioral changes, such as decreased locomotor activity and food consumption; and energy expenditure, which could be associated with changes observed on central mechanisms subjected to seasonal control, such as dopaminergic and somatostatinergic systems. Furthermore, considering that these results could be beneficial for the treatment of obesity, CAF fed animals were also studied at the same photoperiodic conditions and supplemented with the red-grape treatment. Results revealed that obesity dampens the effects of fruit consumption in behavior and in central and peripheral controllers of seasonality observed in the normoweight cohort. Finally, photoperiod sensitivity in both phenotypes consuming red-grape was assessed. Results revealed that obesity impairs seasonal control of prolactin release and the response to hypothalamic-pituitary-adrenal, hypothalamic-pituitary-gonadal and hypothalamic-pituitary-thyroidal axis to changes in photoperiod, therefore producing an insensitivity to photic and non-photic cues. This thesis work highlights the relevance of seasonality of fruits and its consumption for the modulation of brain function by nutrition, and furthermore, provides new evidences for considering seasonal adaptation as a relevant element for prevention and treatment of diseases.