phase I detoxification

phase I detoxification,

n the first step in the two-step process for neutralizing toxic chemicals in the liver, during which enzymes neutralize a few chemicals but convert the majority of them into forms that can be neutralized in phase II. See also phase II detoxification.
References in periodicals archive ?
while much is known about the role of Phase I enzymes in the metabolism of pharmaceuticals as well as their activation by environmental toxins, the role of Phase I detoxification in clinical practice has received less consideration than the Phase II enzyme systems.
Toxins are broken down in the liver during phase I detoxification involving the cytochrome P450 enzymes.
He noted that phase I detoxification can actually render toxins more noxious and generate reactive oxygen species and hydroxyl radicals.
Various nutrients are required in order for the Phase I detoxification system to be carried out efficiently.