Attenuative effects of tamarixetin against polystyrene microplastics-induced hepatotoxicity in rats by regulation of Nrf-2/Keap-1 pathway.

Polystyrene microplastics (PS-MPs) are environmental contaminants due to their potential to induce damages in multiple organs specifically liver. Tamarixetin (TMT) is a naturally occurring flavonoid present in Tamarix ramosissima plant that exhibits multiple pharmacological properties. Therefore, the present research was designed to evaluate the palliative role of TMT against PS-MPs instigated liver dysfunction in rats. The exposure to PS-MPs reduced the expressions of nuclear factor erythroid 2-related factor 2 and antioxidant genes, while increasing the expression of Kelch-like ECH-associated protein 1. PS-MPs exposed rats exhibited considerably (p < .05) higher alkaline phosphatase (ALP), aspartate aminotransferase (AST) as well as alanine aminotransferase (ALT) contents. Additionally, PS-MPs treatment resulted in a notable decrease in anti-oxidants activity, that is, glutathione S-transferase (GST), superoxide dismutase (SOD), heme oxygenase-1 (HO-1), glutathione reductase (GSR), glutathione peroxidase (GPx), catalase (CAT) and glutathione (GSH) content, whereas upregulating reactive oxygen species (ROS) and malondialdehyde (MDA) contents. Moreover, PS-MPs intoxication noticeably increased (p < .05) the inflammatory indices (interleukin-1ß [IL-1ß], nuclear factor kappa B [NF-κB], interleukin-6 [IL-6], tumor necrosis factor-α [TNF-α] levels, and cyclooxygenase-2 [COX-2] activity). Besides, Caspase-3 and Bax expressions were upregulated and Bcl-2 expression was decreased after PS-MPs exposure. Additionally, the histomorphological examination revealed notable hepatic damage in PS-MPs treated group. However, TMT treatment substantially (p < .05) recovered all the PS-MPs-induced damages and histopathological changes. Taken together, it can be deduced that TMT might be used as a pharmacological agent to ameliorate hepatic damage.