Antioxidant Carbon Dots Nanozymes Alleviate Stress-induced Depression by Modulating Gut Microbiota

Depression is a debilitating mental illness that severely threatens millions of individuals and public health. Because of the multifactorial etiologies, there is currently no cure for depression; thus, it is urgently imperative to find alternative antidepressants and strategies. Growing evidence underscores the prominent role of oxidative stress as key pathological hallmarks of depression, making oxidative stress a potential therapeutic target. In this study, we report a N-doped carbon dot nanozyme (CDzyme) with excellent antioxidant capacity for treating depression by remodeling redox homeostasis and gut microbiota. The CDzymes prepared via microwave-assisted fast polymerization of histidine and glucose exhibit superior biocompatibility. Benefiting from the unique structure, CDzymes can provide abundant electrons, hydrogen atoms, and protons for reducing reactions, as well as catalytic sites to mimic redox enzymes. These mechanisms collaborating endow CDzymes with broad-spectrum antioxidant capacity to scavenge reactive oxygen and nitrogen species (