Therapeutic Benefits of Nano-Echinacea Extract on Reproductive Injury Induced by Polystyrene Plastic Materials in Rat Model via Regulating Gut–Brain Axis

Plastics pollution is a critical global environmental issue, with growing concern over the increasing presence of nanoplastic particles. Plastics are major environmental pollutants that adversely affect human health, particularly when plastics from food sources enter the body and pose potential risks to reproductive health. <i>Echinacea purpurea</i> is an immunologically active medicinal plant containing phenolic acids and alkylamides. Nanoparticles present a promising approach to enhance the effectiveness, stability, and bioavailability of <i>Echinacea purpurea</i> ethanol extract (EE) active components. This study aimed to determine the protective effects of chitosan-silica-<i>Echinacea purpurea</i> nanoparticles (CSE) against reproductive injury induced by polystyrene nanoplastics (PS-NPs) in male rats. The results showed that CSE dose-dependently reduced oxidative damage and protected intestinal and reproductive health. Furthermore, CSE improved gut microbiota dysbiosis, preserved barrier integrity, and attenuated PS-NPs-induced inflammation in the colon, brain, and gonads. Inflammatory factors released from the gut can enter the bloodstream, cross the blood-brain barrier, and potentially modulate the hypothalamic-pituitary-gonadal (HPG) axis. CSE has also been shown to elevate neurotransmitter levels in the colon and brain, thereby repairing HPG axis dysregulation caused by PS-NPs through gut-brain communication and improving reproductive dysfunction. This study enhances our understanding of CSE in modulating the gut-brain and HPG axes under PS-NPs-induced damage. CSE demonstrates the capacity to provide protection and facilitate recovery by mitigating oxidative stress and inflammation, restoring gut microbiota balance, and preserving hormone levels in the context of PS-NPs-induced injury.