Environmental toxicology examines how chronic, low-dose exposure to synthetic xenobiotics—including endocrine-disrupting chemicals (EDCs), microplastics, heavy metals, and persistent organic pollutants—alters human hormonal signaling, reproductive function, and metabolic pathways.
Phase I and Phase II Hepatic Biotransformation Pathways
Hepatic clearance of lipophilic xenobiotics requires a coordinated two-phase enzymatic system:
- Phase I Functionalization (Cytochrome P450 Enzymes): Introduces reactive polar functional groups (-OH, -COOH, -NH₂). Requires adequate iron, riboflavin (B2), niacin (B3), and zinc.
- Phase II Conjugation: Attaches hydrophilic moieties (glutathione, sulfate, glucuronate, glycine) to neutralize Phase I intermediates. Supported by dietary sulfur donors (sulforaphane from cruciferous vegetables, N-acetylcysteine) and methyl donors (choline, folate, B12).