Hepatotoxic Effect of Combined Exposure of Arsenic and Microplastics on Labeo Rohita: An In-Vivo Experimental Study

Background: Arsenic (As) is one of major environmental toxicants that adversely affect living organisms. Microplastics (MPs) are small plastic particles that are hazardous because they may be toxic or conjugate with some toxic elements. Objective: The present research was conducted to assess whether the treatment of As with polystyrene microplastics (PS-MPs) enhance their toxic effects on the hepatic tissues of Labeo rohita. Methods: The experiment was conducted at Government College University, Faisalabad, using 85 healthy Labeo rohita (average 8.91 cm, 7.3 g). Fish were acclimatized and randomly divided into four groups i.e., control group, As treatment group (4.05mgL−1), PS-MPs treatment group (1mgL−1), and As (4.05mgL−1) plus PSMPs (1mgL−1) combined treatment group for 21 days. Blood and liver samples were collected post-treatment for hematological, antioxidant, hepatic, and inflammatory analyses. Enzymatic activities and biomarkers were measured using standard biochemical methods. Results: Exposure to As and PS-MPs, especially their combination, significantly reduced RBCs and hemoglobin, increased WBCs, and suppressed antioxidant enzyme activities (SOD, CAT, GST). Reactive oxygen species (ROS) and Thiobarbituric acid reactive substances (TBARS) levels were elevated, indicating oxidative stress. Liver enzymes (ALT, AST) and inflammatory cytokines (IL-1β, IL-6) were significantly higher in the As+PS-MPs group compared to individual treatments or control. Conclusion: Co-exposure to As and PS-MPs caused severe hematological, oxidative, hepatic, and inflammatory disturbances in L. rohita. Their combined toxicity was greater than individual exposures, indicating a synergistic effect that may lead to pronounced liver damage and physiological dysfunction.