Battling Oxidative Stress: The Effects of Nano-Antioxidants on Saccharomyces cerevisiae’s Response to Oxidizing Agent Exposure
Catherine Diyakonov
Lord Byng Secondary
Floor Location : S 064 H

Oxidative stress is a state which is widespread, as neurodegenerative diseases are extremely common, being among the top five causes of death worldwide. With this in mind, I wanted to go into greater depth of oxidative stress, and the measures which can be taken to prevent and reduce the amount of harm oxidative stress can do to one’s body. Nano-antioxidants have been involved in many research experiments, but there haven’t been any experiments regarding mixes of nano-antioxidants and their effects on oxidative stress. I decided to use Saccharomyces cerevisiae as a model organism, inducing oxidative stress with the use of hydrogen peroxide. Because S. cerevisiae is so similar to the molecular makeup of human cells, this organism was the most practical one to experiment with. Furthermore, hydrogen peroxide has been shown to cause oxidative stress, as it is converted from a particular type of free radical which leaks from the mitochondria. With this in mind, I then decided to test three nano-antioxidants: C60 Fullerene, MitoQ, and Silver Nanoparticles. Not only would these nano-antioxidants be tested separately, but they would also be tested in pairs, making a total of six combinations. Each of these six combinations would then be tested in three concentrations (0.05mg/mL. 0.225mg/mL, and 0.5mg/mL). This made a total of 18 solutions which were tested upon. In addition, there were two control groups used to compare my results: yeast and the base solution, and yeast, the base solution, and hydrogen peroxide. I measured the optical density of each solution using a handheld colorimeter just after the samples were made, as well as after 24 hours. After performing five trials on each of the 18 solutions, I gathered my data and analyzed it in a variety of media including tables and graphs. In addition, I statistically analyzed my two best results: C60 Fullerene (a single nano-antioxidant) and C60 Fullerene and MitoQ (a mix of nano-antioxidants). I used a one-way ANOVA test and found that C60 Fullerene had a p-value of < 0.00001, making the result significant at p < 0.01. The f-statistic was greater than the critical value, and therefore we rejected our null hypothesis. The C60 Fullerene and MitoQ solution also had a p-value of < 0.00001, making the result significant at p < 0.01. We rejected our null hypothesis because the f-statistic was greater than the critical value, meaning that there was an extremely low chance of error, and our results are statistically significant. There was a significant difference in our nano-antioxidant mixes, a result we can continue to research upon.