Unraveling the endocrine disruption potential of microplastics in testosterone regulation

Microplastics (MPs) are increasingly recognized as emerging endocrine disrupting chemicals with significant implications for male reproductive health. Despite of well documentation on widespread presence in the environment, their specific effects on testosterone synthesis in humans remain insufficiently characterized. Current in vivo studies demonstrate that MPs impair androgen regulation through several interconnected mechanisms. These include oxidative stress-induced damage to Leydig cells, downregulation of antioxidant enzymes such as GPX1, disruption of the LH/cAMP/PKA/StAR signaling cascade essential for steroidogenesis, activation of NF-κB and inflammatory pathways, and induction of endoplasmic reticulum stress that accelerates testosterone metabolism. Additionally, MPs and their chemical additives interfere with steroidogenic enzymes and hormone receptors. Our review consolidates mechanistic insights linking MPs to testosterone disruption, underscores the dose-dependent nature of these effects. We also highlight critical knowledge gaps particularly the paucity of human data, the physicochemical diversity of MPs, and the long-term reversibility of endocrine disruption.