Stevioside extends the healthspan and improves Alzheimer's disease and increases oxidative stress resistance via the mitochondrial unfolded protein response

Abstract

Increased evidence suggests that moderate activation of the mitochondrial unfolded protein response (UPR^mt) can delay aging and ameliorate neurodegenerative pathologies. Stevioside (Ste), a natural zero-calorie sweetener extracted from Stevia rebaudiana, has gained global acceptance as a sugar substitute in the food industry. Accumulated studies indicate that stevioside exhibits a wide spectrum of biological effects, including anti-hyperglycemic, anti-hypertensive, anti-inflammatory, and antimicrobial activities. However, its potential roles in aging and neurodegenerative diseases remain poorly understood. In this study, the lifespan of Caenorhabditis elegans was found to be prolonged upon exposure to (1, 10, and 100 μM) stevioside in a dose-dependent manner. Furthermore, we found that stevioside extended the lifespan and healthspan in C. elegans via activation of the ATFS-1-mediated UPR^mt pathway. Intriguingly, the amelioration of Alzheimer's disease-related phenotypes by stevioside was also mediated through the ATFS-1 pathway. Additionally, we found that stevioside increased the resistance of oxidative stress and reduced ROS levels and upregulated superoxide dismutase (SOD) activity in C. elegans via the ATFS-1 pathway. These results demonstrated that both the anti-aging and neuroprotective effects of stevioside in C. elegans required a functional ATFS-1-dependent mitochondrial unfolded protein response. Collectively, our work highlighted that stevioside might be a viable candidate for the prevention and treatment of aging and age-related diseases.