Preventive and Protective Effects of Nicotinamide Adenine Dinucleotide Boosters in Aging and Retinal Diseases

Nicotinamide adenine dinucleotide (NAD⁺) boosting can sustain energy metabolism and neurovascular stability in the retinal tissue. Depletion of NAD⁺ is linked to the development of pathological retinal conditions, such as age-related macular degeneration (AMD) and diabetic retinopathy (DR). Mitochondrial dysfunction, oxidative stress, and inflammation occur in these diseases. This review summarizes substantial evidence of therapeutic NAD⁺ boosters, including nicotinamide, nicotinamide mononucleotide, or nicotinamide riboside. They help improve mitochondrial function and lessen neurovascular injury. We also emphasize the importance of natural products and sirtuins in facilitating cytoprotective effects through the regulation of mitochondrial balance and inflammation. Developments in drug delivery methods, such as nanoparticle encapsulation and targeted eye treatments, are promising for enhancing the bioavailability and effectiveness of NAD⁺ boosters. The novelty of this work is its combination of mechanistic insights regarding NAD⁺ metabolism with efficacy data from preclinical studies. Furthermore, natural products may work together to boost their therapeutic effects against retinal damage. Together, our review article highlights NAD⁺ metabolism as a potential therapeutic target for addressing retinal degeneration and maintaining vision in aging, neurologic disorders, and various metabolic diseases, including diabetes.