Circannual Rhythms Affect the Bioavailability of Phenolic Compounds from Grape Seed Proanthocyanidins Extract Differently in Healthy and Obese Fischer 344 Rats

(Poly)phenols are plant-derived bioactive molecules that are associated with several health benefits. Therefore, it is essential to study the factors that affect the bioavailability of these phenolic compounds. Recently, circannual rhythms have been identified as one of the factors that may affect the bioavailability of these compounds. Hence, this study evaluates the impact of circannual rhythms on grape seed proanthocyanidins extract (GSPE) bioavailability in healthy and obesogenic contexts. Male Fischer 344 rats, fed standard (ST) or cafeteria (CAF) diets, were housed under different photoperiod conditions (6, 12, or 18 h of light per day) during 9 weeks and an oral dose of GSPE (25 mg/kg) was daily administered for the last 4 weeks. Serum GSPE-derived metabolites were then quantified by HPLC-ESI-MS/MS. A higher bioavailability was observed in rats exposed to a 12 h photoperiod and fed ST diet. However, this pattern was altered in CAF-fed rats, suggesting an attenuated influence of photoperiod under obesogenic conditions. These findings contribute to a better understanding of the complex relationships between diet, photoperiod, and serum metabolites.