Catalase Activity in the Presence of Pure Flavonoids

Catalase is an enzyme which catalyzes hydrogen peroxide into water and molecular oxygen. Flavonoids inhibit catalase, which allows for a buildup of hydrogen peroxide in our bodies that is important when we are sick. Pure flavonoids, like those found in colorful fruits and vegetables, will inhibit catalase by reducing the enzymes’ ability to break down hydrogen peroxide. The pure flavonoids that we looked at are hesperidin and naringenin, found in citrus fruits, and quercetin, found in vegetables like onions and hot peppers. Plant flavonoids are seen to inhibit catalase but are found bounded to compounds like sugars while pure flavonoids are the isolated version without being bounded to anything else. Previous work demonstrated the plant extracts did inhibit catalase activity. This experiment uses a colorimetric assay to test if catalase found in the presence of pure flavonoids would also be inhibited or not. If the solution turned pink, it meant that catalase was not being inhibited, however if it turned green it was clear that the flavonoid was inhibiting catalase. The different flavonoids were tested using a spectrometer that measured the absorption of the different flavonoids at a wavelength of 629nm. All flavonoids were found to inhibit catalase at varying levels depending on concentration which is important because it protects our cells from oxidative damage.