Effect of piceatannol on circadian Per2 expression in vitro and in vivo

In addition to the development of chrononutrition, food ingredients have been demonstrated to contribute to expression changes in the peripheral clock genes responsible for circadian rhythms. Passion fruit seeds extract (PFSE) contains a high concentration of piceatannol that exhibits many physiological activities; however, whether PFSE and piceatannol affect clock genes is not known with certainty. In this study, we evaluated the effects of PFSE and piceatannol on the rhythm of PER2 using bioluminescence in mPer2 ^Luc knock-in mice and their embryonic fibroblasts. Piceatannol was demonstrated to advance and delay the phase of PER2::LUC oscillation owing to differences in timing of treatment in vitro. In the in vivo imaging system, oral administration of piceatannol significantly advanced the luminescence rhythm of PER2::LUC in peripheral organs. Furthermore, piceatannol recovered the phase change of PER2::LUC disturbed by high-fat diet intake. These findings indicate that piceatannol affects peripheral clock gene expression and may prevent circadian disturbance.