Abstract

Neuroinflammation and cognitive decline are the key pathological features in aging that bring detrimental impacts upon quality of life. However, there is no effective anti-aging pharmacological therapy thus far. Dietary supplements in particular essence of chicken (EC) has been found to be an effective remedy for alleviating mental stress and improving memory. In addition, a novel hydrolyzed chicken extract, ProBeptigen/CMI-168 (PB), showed beneficial effects on cognitive ability. However, the antiaging effect and possible mechanism of PB and EC are still unknown. Here, we investigated the antiaging effects of PB and EC on hippocampus-related cognitive decline and neuroinflammation in aged mice. PB and EC were administered for 16 weeks in 10-month-old mice. Both PB and EC treatments ameliorated age-related deterioration of learning and memory, and attenuated oxidative stress and inflammation in the hippocampus. These results were associated with decreased inflammatory cytokine levels and increased neurotransmitter levels in the hippocampus. The overall effects of improving aging-induced cognitive decline were more robust in PB-treated mice, while EC was effective in decreasing oxidative stress and inflammation. Moreover, alterations in the diversity and composition of the gut microbiota in aged mice were also regulated by both PB and EC, which induced distinguished features in the gut microbiota and their related functions. This study showed that PB exerts neuroprotective effects in aged mice, the mechanism of which might be different from that of EC. Therefore, PB has a potential as dietary supplement for ameliorating cognitive dysfunction and neuroinflammation in elderly individuals.