Document Type

Honors Thesis

Major

Biochemistry, Microbiology

Advisor(s)

Jennifer Newell-Caito

Committee Members

Suzanne Angeli, Zhao Xuan

Graduation Year

May, 2025

Publication Date

2025

Abstract

Antioxidants are vital to maintaining human health, as they can help prevent damage caused by oxidative stress. Oxidative stress is caused by an imbalance of free radicals to antioxidants within the body and it has been linked to conditions such as cancer, Alzheimer’s disease, and cardiovascular disease. Cedar bark has been used in medicinal teas by Indigenous communities in North America and may have antioxidant properties based on its high polyphenolic content. Unfortunately, the science behind traditional Indigenous practices is a severely under researched field of study. This study aims to examine the potential antioxidant effects of cedar bark extract (CBE) using the nematode worm Caenorhabditis elegans (C. elegans) as a model organism. The total phenolic content of CBE was determined to be 1720 +/- 450 gallic acid equivalents. Using the known oxidant, manganese chloride (MnCl2) to assess the antioxidant properties of CBE, C. elegans were pretreated with CBE at concentrations less than the median lethal dose (LD50) value for 30 minutes, followed by 30 minutes of exposure to various concentrations of MnCl2. The LD50 of CBE was determined to be 16% of the total volume of solution. Using this methodology, this project examined several biochemical pathways affected by MnCl2 induced oxidative damage. Specifically, we examined levels of reactive oxygen species, ATP, and advanced glycation end products as well as the activation of the SKN-1 transcription factor and the impact on C. elegans lifespan. To assess neurodegeneration, aversion of worms to chemical stimuli was examined. From the data collected we can conclude that pretreatment of CBE at low concentrations reduced oxidative stress caused by MnCl2.

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