Investigating the protective effects of epigallocatechin-gallate against polystyrene microplastics-induced biochemical and hematological alterations in rats

Polystyrene microplastics (PS-MPs) are widely used and found in drinking water and food, concerns have been raised about their potential health effects, especially in causing oxidative stress and inflammation in living organisms. The aim of this study was to investigate the protective effects of epigallocatechin-gallate (EGCG), a natural antioxidant and anti-inflammatory compound, against PS-MPs-induced biochemical and hematological alterations in rats. Male Wistar rats were divided into four groups: control, EGCG-treated (80 mg∙ kg -1 /d), PS-MPs-exposed (0.01 mg∙kg -1 /d), and PS-MPs+EGCG-treated groups. PS-MPs were orally administered for 56 days, while EGCG was given concomitantly by gavage. At the end of the treatment period, blood samples were collected for hematological and biochemical analyses. Oxido-nitrergic stress markers, including malondialdehyde (MDA), nitric oxide (NO), reactive nitrogen species (RONS) and reduced glutathione (GSH), Superoxide dismutase (SOD), catalase (CAT), as well as inflammatory markers, such as tumor necrosis factor alpha (TNF-α), interferon gamma (IFN-γ) and interleukin-10 (IL-10), were also measured in serum. Treatment with PS-MPs caused a significant increase in MDA, RONS, NO levels and a decrease in SOD, CAT and GSH levels, indicating the induction of oxido-nitrergic stress. PS-MPs also caused an increase in the levels of TNF-α, IFN-γ, MPO and decreased IL-10, indicating the induction of inflammation. Additionally, PS-MPs caused alterations in hematological and serum transaminase parameters, including a decrease in red blood cell count, hemoglobin, and hematocrit levels, neutrophil and eaosinophil and an increase in white blood cell count, lymphocyte count, AST, ALT, ALP, LDH and GGT. PS-MPs also caused disturbances in electrolyte balance and renal function markers. However, treatment with EGCG significantly attenuated these alterations induced by PS-MPs, indicating its protective effects. The results of this study demonstrate that EGCG can protect against PS-MPs-induced biochemical and hematological alterations in rats, possibly through its antioxidant and anti-inflammatory properties.