Chronotherapeutic role of grape seed proanthocyanidins on circadian rhythm and oxidative stress in an obesity context

Identifier:  TDX:4277

Handle: https://hdl.handle.net/20.500.11797/TDX4277

Authors:  Cortés Espinar, Antonio Jesús

Abstract:
Biological rhythms allow the organisms to adapt to predictable environmental changes promoted by the rotation and translation movements of Earth. Those movements determine the oscillations through the days (circadian) and the years (circannual rhythms), being synchronized by external cues or zeitgebers. However, misaligned external cues such as the promoted by modern lifestyles can contribute to desynchronize biological rhythms, leading to the promotion of metabolic diseases (obesity and metabolic syndrome) and oxidative stress. Grape seed proanthocyanidin extract (GSPE) has shown potential to ameliorate metabolic diseases, oxidative stress, and circadian disruptions. Therefore, the aim of this thesis was to study the chronotherapeutic effects of GSPE on hepatic antioxidant metabolism after a circadian disruption induced by misaligning cues, including an hypercaloric diet or a sudden change in the light/dark cycles. To this end, the diurnal oscillations of the liver antioxidant system, the impact of an abrupt change of photoperiod on this system and the effects promoted by GSPE were studied in healthy and cafeteria diet (CAF)-induced obese Fischer 344 rats. The CAF triggered a disruption of the diurnal oscillations of the antioxidant enzyme activity and gene expression in the liver.