Detoxification enzymes function through a series of biochemical reactions classified into three phases:
Phase I involves the introduction or exposure of functional groups on the xenobiotic. This is primarily carried out by the cytochrome P450 enzyme family, which oxidizes, reduces, or hydrolyzes the toxins. Phase II entails conjugation reactions where the modified toxins from Phase I are linked to endogenous molecules like glutathione, sulfate, or glucuronic acid. Enzymes like glutathione S-transferases (GSTs) and UDP-glucuronosyltransferases (UGTs) are pivotal in this phase. Phase III involves the transport of these conjugated toxins out of the cells, facilitated by ATP-binding cassette (ABC) transporters, thereby preparing them for excretion via urine or bile.
