Dopamine Enhances Healthspan and Locomotor Performance via Antioxidant Defense in Silkworms, Bombyx mori

The impact of dopamine on aging is complex and context-dependent. This study systematically investigated the effects of dopamine levels on the lifespan and behavior of the silkworm moth by employing genetic mutants of the dopamine synthesis/metabolic pathway combined with pharmacological interventions. The results demonstrated a significant positive correlation between endogenous dopamine levels and adult lifespan. Reducing dopamine levels shortened lifespan, whereas a moderate peripheral administration significantly extended healthspan, improved locomotor activity, and restored motor vigor in aged moths, though an excessive dose was toxic. The lifespan-extending effect of dopamine was closely correlated with enhanced total antioxidant capacity, observed in both long-lived strains and dopamine-treated individuals. Dopamine's effects also exhibited sexual dimorphism and age dependency. This research reveals that a moderate increase in systemic endogenous dopamine or peripheral dopamine administration exerts positive effects on lifespan and aging-related behaviors, an effect likely mediated by enhanced antioxidant defense. These findings not only advance our understanding of the role of dopamine in the aging process but also provide a novel theoretical framework for developing anti-aging therapies and breeding superior silkworm strains.