Pyridoxal-5-phosphate mitigates age-related metabolic imbalances in the rat heart through the H2S/AKT/GSK3β signaling axis.

Pyridoxal-5-phosphate (PLP) enhances the synthesis of endogenous hydrogen sulfide, a potent regulator of cell metabolism. We used 24-month-old rats to investigate the PLP mitoprotective function in the aging heart. We demonstrated improvement of mitochondrial bioenergetic functions, inhibition of mPTP opening after PLP administration. Moreover, PLP treatment increased glucose consumption and utilization, decreased lipid transport into the cells, but increased fatty acid β-oxidation, providing sufficient energy. An ECG study showed a significant improvement in cardiac function in PLP-treated old rats. Our data suggest that PLP may exert its effect through the H2S/AKT/GSK3β axis with further targeting of the Sirt1/PGC-1α signaling pathway.