Behavioral Changes and Survival in <i>Drosophila melanogaster</i>: Effects of Ascorbic Acid, Taurine, and Caffeine

In this study, we used Drosophila as a model species to examine the effects of vitamin or energy-drink and theses ingredients on behavioral activity, life-span, and survivorship. Behavioral assays were performed to analyze total activity during the subjective daytime and nighttime and the lifespan assay was performed to investigate the influence of the drink ingredients. Quantitative RT-PCR and enzyme activity analyses were applied to analyze the mutual relationship of neural pathways and anti-oxidant activities. Caffeine and taurine treatments resulted in significant differences between the control and ascorbic acid groups with respect to subjective daytime and nighttime activity (p<0.05). Additionally, the lifespan and survival on individual flies significantly decreased with 1.6% taurine, and 0.025 and 0.05% caffeine treatment compared to the normal group (p<0.05). These results are related to the transcript levels of neuromodulator (p<0.05). In addition, ascorbic acid treatments significantly increased the activity of antioxidant-related enzymes (p<0.05). We successfully demonstrated that 0.5 and 1.0% ascorbic acid increases the lifespan of fruit flies to a greater extent than 1.6% taurine, and 0.025 and 0.05% caffeine, and that this effect is driven by changes in gene expression and the activity of oxidative stress-related enzyme. In summary, these findings support the use of ascorbic acid as a drink ingredient to enhance body function. Use of the fruit fly in combination with behavior activities and biological processes is recommended for validating the effects of functional substances used by the drink and food industry.