Attenuating free radical damage with fermented Geoje yuzu in Drosophila

Introduction: Yuzu, a yellow citrus fruit from a plant belonging to the Rutaceae family, is a popular ingredient in many types of processed beverages. However, the long-term consequences of yuzu consumption at the organism level have not been thoroughly studied yet. Post-harvesting methods and cultivation methods may influence the reported health-promoting properties of yuzu, including antioxidant, anti-inflammatory, and anti-cancer effects. Therefore, we chose Drosophila as an animal model to evaluate the beneficial effects of yuzu that is cultivated and processed through fermentation in Geoje, South Korea. We examined in vivo effects of fermented yuzu on Drosophila during its lifetime. Methods: Using lifespan assay, flies were fed fermented Geoje yuzu (FGY) and their survival was monitored. In healthspan assays, flies fed with FGY were exposed to environmental stresses, such as starvation, hydrogen peroxide, or carbon dioxide (CO2). Effects of FGY on improving ability of flies to withstand these stresses were assayed. Results: Consumption of yuzu did not increase lifespan of the flies nor their capacity to withstand starvation and CO2 stress. However, it significantly protected the flies from oxidative stress, as evidenced by an increase in the survival rate of flies fed a diet supplemented with FGY when exposed to hydrogen peroxide. Conclusion: This research found that FGY protects flies from oxidative stress. These results may pave the way for future research on long-term health-promoting properties of yuzu, ultimately fostering collective efforts to maximise health benefits of yuzu.