Taurine attenuates polystyrene microplastic-associated oxidative stress, inflammation, and apoptotic changes in the...

Microplastic (MP) contamination is an emerging environmental threat with potential adverse effects on oxidative stress, immune function, and inflammatory homeostasis. This study investigated the oxidative stress, pro-inflammatory, and immunotoxic effects of polystyrene microplastics (PMPs) and evaluated the protective role of the nutraceutical taurine (TN) in male Swiss mice following 60 days of oral exposure.

Mice were assigned to four groups: control, PMPs (10 mg/kg b.wt.), TN-treated (200 mg/kg b.wt.), and PMPs + TN. Hematological parameters and serum immune markers, including immunoglobulins G and M (IgG and IgM), complement component 3 (C3), and nitric oxide (NO), were assessed. Splenic tissue was analyzed for oxidative stress markers, including malondialdehyde (MDA), catalase (CAT), and superoxide dismutase (SOD); pro-inflammatory mediators, including tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), and nuclear factor kappa B (NF-κB); apoptotic markers, including caspase-3 and B-cell lymphoma 2 (BCL-2); and immune-regulatory genes, including cluster of differentiation 4 and 8 (CD4 and CD8). Histopathology (hematoxylin and eosin (H&E) and periodic acid-Schiff (PAS) staining) and immunohistochemistry for cyclooxygenase-2 (COX-2) and caspase-3 were performed to evaluate structural alterations and inflammatory/apoptotic signaling in the spleen.

PMPs exposure induced significant hematological disturbances, systemic inflammation, immune alterations, and elevated NO levels. In splenic tissue, PMPs caused oxidative stress and inflammation, evidenced by increased MDA, and TNF-α levels and reduced CAT and SOD activities. Histological and immunohistochemical analyses revealed structural splenic damage with enhanced Caspase-3 and COX-2 expression, indicating elevated apoptosis and inflammatory signaling. Gene expression analysis revealed upregulation of IL-1β, TNF-α, NF-κB, and Caspase-3, and CD8, wheras BCL-2 and CD4 were significantly downregulated. Taurine supplementation effectively mitigated PMPs-induced effects by restoring hematological, alleviating immune alterations, enhancing antioxidant defenses, reducing inflammatory and apoptotic markers, and improving gene expression profiles.

These findings demonstrated that TN exerts protective effects against PMPs-induced oxidative stress, inflammation, apoptosis, and immune-related alterations in splenic tissue. TN partially attenuated PMPs-induced immunotoxic and histopathological changes in this experimental mouse model, although further mechanistic, dose-response, and functional immune studies are required to confirm its potential therapeutic or nutraceutical applications against PMPs -induced toxicity.