The Pressing Issue of Micro- and Nanoplastic Contamination: Profiling the Reproductive Alterations Mediated by Oxidative Stress

Abstract

Micro- and nanoplastics (MPs/NPs) are among the most widely distributed pollutants in the environment. It has been suggested that exposure to MPs/NPs can trigger toxicity pathways among which inflammation and oxidative stress (OS) play a pivotal role. Once absorbed, MPs/NPs may act locally or access the bloodstream and, following the translocation process, reach several organs and tissues, including the gonads. Notably, MPs/NPs can bioaccumulate in human and murine placenta, opening new scenarios for toxicological evaluations. We review recent studies on the effects of MPs/NPs on the reproductive health in aquatic and terrestrial organisms of both sexes, focusing on the role of OS and the antioxidant defence system failure as the main underlying mechanisms. Alterations in gametogenesis, embryonic and offspring development, and survival have been shown in most studies and often related to a broken redox balance. All these detrimental effects are inversely related to particle size, whereas they are closely linked to shape, plastic polymer type, superficial functionalization, concentration, and time of exposure. To date, the studies provide insights into the health impacts, but no conclusions can be drawn for reproduction toxicity. The main implication of the few studies on antioxidant substances reveals their potential role in mitigating MP-induced toxic effects.

Effects of microplastics, pesticides and nano-materials on fish health, oxidative stress and antioxidant defense mechanism

“…After ingestion, microplastics may affect a specific area or enter the blood and reach several organs and tissues. Moreover, microplastics bioaccumulate in the human body and exerts toxicological effects ( Ferrante et al, 2022 ). Microplastics trigger ROS production through mitochondrial damage or by increasing the immune system responses while neutralizing harmful foreign particles ( Yang et al, 2020 ).…”

Impact of Microplastics and Nanoplastics on Livestock Health: An Emerging Risk for Reproductive Efficiency

“…Not to be underestimated are the biodegradable plastics, which presence in the environment is increasing due to incomplete biodegradability and increasing use [ 9 , 10 ]. The ecotoxicological effects of MPs/NPs on marine phytoplanktons and zooplanktons, invertebrates and plants are well documented, while ingestion and accumulation from marine prey, leading to transfer to the predators, also occur [ 11 , 12 ]. The distribution of plastics is ubiquitous in the environment and includes atmosphere, soil and water; this likely represents a potential entry of microplastics into the food chain and, therefore, a concern for human and animal health.…”

Molecular effects of polystyrene nanoplastics on human neural stem cells

“…Previous studies have described that NPs can stimulate reactive oxygen species (ROS) production and cause oxidative stress in human cells [64], Zfe [17,21,[63][64][65], and in Daphnia pulex and Karenia mikimotoi [66]. Increased ROS can generate oxidative stress, mitochondrial damage, amplified inflammatory cytokines and proapoptotic factors that could induce apoptosis in cells and in animals [56,[67][68][69][70].…”