The memory improving effects of round scad (Decapterus maruadsi) hydrolysates on sleep deprivation-induced memory deficits in rats via antioxidant and neurotrophic pathways

Sleep deprivation negatively influences the memory formation and consolidation, which leads to a memory impairment associated with oxidative stress and neurotrophic pathways. In this study, the sleep-deprived rat model was used to evaluate the protective effects of round scad hydrolysates (RSH, 333 and 666 mg/kg bw) on memory impairment and the underlying mechanisms. The result of Morris water maze test revealed that RSH significantly reversed the cognition deficits induced by sleep deprivation. Moreover, RSH supplementation alleviated oxidative stress via increasing the activities of glutathione peroxidase and superoxide dismutase and the ratio of glutathione/oxidized glutathione in brain. Furthermore, RSH significantly up-regulated the expression of antioxidant defense-related protein including nuclear factor E2-related factor 2(Nrf2) and its downstream heme oxygenase-1 (HO-1) as well as the phosphorylation of Akt in rats. Moreover, RSH improved the expression of brain-derived neurotrophic factor (BDNF)，the phosphorylation of cAMP response element-binding (CREB) and tropomyosin-related kinase B (TrkB) in vivo, indicating that RSH could also promote the expression of protein which was related to neurotrophic pathway. Additionally, UPLC-qTOF-MS/MS was further used to identify the peptides. The results indicated that RSH was mainly consisted of low molecular weight peptides with hydrophobic, aromatic and positively charged amino acids in sequence. Taken together, these findings demonstrated that RSH exerted memory-improving actions through regulating the antioxidant and neurotrophic pathways, and RSH can be a potential functional ingredient for prevention and protection of cognitive deficits.