Effect of Turmeric on Oxidatively Stressed Tetrahymena thermophila Cells

Abstract

Reactive oxygen species (ROSs) are chemically reactive forms of oxygen that, within a cellular environment, form free radicals that interfere with cellular processes and damage DNA. ROSs are routinely produced during oxidative metabolic processes that occur within the mitochondria and their presence in the cell must be tightly regulated. The OXR1 gene encodes a protein that is essential to the degradation of ROSs primarily in the nucleus and in the mitochondria. In this study, we wanted to determine whether turmeric had a protective effect on ROS-induced oxidative stress through regulation of the OXR1 gene in the model organism Tetrahymena thermophila. Turmeric is a spice produced from a species of ginger root that has been used for centuries as an antioxidant and anti-inflammatory agent. We hypothesized that turmeric would have a negligible effect on OXR1 gene expression and cell growth in Tetrahymena that were experiencing high levels of ROS-induced oxidative stress. To test our hypothesis, experimental groups of Tetrahymena cells were exposed to the oxidative stress inducer oligomycin for one week in the presence of turmeric extract while control groups of cells were treated solely with oligomycin. During the week-long exposure, Tetrahymena cells were counted every 24 hours to determine growth grate. At the end of the exposure, RNA was extracted from the control and experimental groups and Reverse Transcription quantitative Polymerase Chain Reaction (RT-qPCR) was performed to measure the expression of OXR1. We predicted that turmeric would have no effect on OXR1 expression and cell growth in Tetrahymena thermophila.