Dietary Natural Melanin Nanozymes Delay Aging and Ameliorate Neurodegeneration via Improving Gut Microbiota and Redox Homeostasis

Aging is an inevitable multifactor process that causes a decline in organ function and increases the risk of age-related diseases and death. Thus, the development of highly effective and safe therapeutic strategies to delay aging and age-related diseases is urgently required. In this study, we isolated natural melanin nanozymes (NMNs) from the ink sacs of live octopuses. The NMNs exhibited excellent superoxide-dismutase-mimicking and radical scavenging activities. In SAMP8 mice, treatment with NMNs improved their cognition and memory functions while restoring their aging-impaired liver function and lipid metabolism, thereby prolonging their lifespan. Moreover, the NMNs reversed metabolic changes in their aged brains and reconstructed their gut microbiota composition by enhancing microbial community diversity. Our findings indicate that NMNs treatment could be a promising approach for delaying aging and preventing age-associated physiological decline in humans.