Photoperiod‐Dependent Effects of Phenolic‐Enriched Fruit Extracts on Postprandial Triacylglyceride Levels and Acute Inflammatory Responses in F344 Rats

This study investigated the photoperiod-dependent effects of eight phenolic-enriched fruit extracts on postprandial blood triacylglyceride (TAG) levels and serum cytokine and CRP levels in F344 rats after an oral lipid tolerance test (OLTT) and lipopolysaccharide (LPS)-induced inflammatory challenge, respectively. Animals were exposed to short (6-h light, L6) or long (18-h light, L18) photoperiods and orally supplemented with fruit extracts (100 mg/kg) for 2 weeks. Extracts were obtained from seasonal fruits (cherries, plums, apricots, strawberries, persimmon kakis, grapes, oranges, and pomegranates). Temporal homeostasis disruption was induced by an OLTT and LPS challenge. No differences in blood postprandial TAG levels were observed in the L6- and L12-control groups. However, in the experimental groups, the postprandial TAG response depended on the photoperiod and fruit extract consumption, mainly cherry and plum extracts in L6 (p < 0.05). In addition, control rats exposed to L6 exhibited higher blood IL-6 and TNF-α levels after inducing LPS-inflammatory response. Notably, winter-fruit and strawberry extracts were the most efficient at lowering proinflammatory cytokines. These findings show the effectiveness of specific fruit extracts in modulating postprandial TAG levels and acute inflammatory responses, being their effects photoperiod-dependent, opening the door to the design of functional ingredients specific for each season.