It was determined through a new study that exposure to dose dependent levels of Paraquat is responsive for increasing levels of oxidative stress. At lower level, production of oxidative stress was reduced by activation of the Nrf2. At higher dose levels, Nrf2 activation was inhibited which resulted in higher levels of oxidative stress and tissue damage.
This is important because Paraquat is an important agricultural herbicide that is used around the world. There are numerous reports that it crosses the blood brain barrier and accumulates in different brain regions. Because of this, it is believed that it does damage to dopamine neurons. It has also been found to cross the placenta and has been found in higher concentrations in the placenta than in the mother's blood. For this reason, the exposure to Paraquat may put a fetus at risk when the mother is exposed. In addition, Paraquat exposure has been linked to Parkinson's disease and Nrf2 inhibition at higher levels may to be blame for development of the disease. Of course, since oxidative stress is caused by exposure to Paraquat, people that have diseases or conditions where oxidative stress is a factor may be more negatively effected. (1)
Nrf2/ARE Pathway Involved in Oxidative Stress Induced by Paraquat in Human Neural Progenitor Cells. Oxidative medicine and cellular longevity, Vol. 2016 (2016) by Tingting Dou, Mengling Yan, Xinjin Wang, et al. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4663008/
