Abstract
Cytotoxicity in freshwater fishes induced by industrial effluents and dyes is a global issue. Trypan blue dye has many applications in different sectors, including laboratories and industries. This study determines to detect the cytotoxic effects of trypan blue dye in vivo. The objective of this study was to estimate the sub-lethal effects of azodye in fish. Cirrhinus mrigala, a freshwater fish, was exposed to three different grading concentrations of dye 5 mg/L, 10 mg/L, and 20 mg/L in a glass aquarium. Significant (p < 0.05) decrease in the weight of fish was observed as 0.728 ± 0.14 g and 2.232 ± 0.24 g, respectively, in the trial groups exposed to 10 and 20 mg/L of dye in a week. After exposure to trypan blue dye, fishes were dissected to remove liver and kidney tissues. Histopathological assessments determined hepatotoxicity and nephrotoxicity induced by trypan blue through the paraffin wax method. This dye induces mild alterations in the liver such as congestion, hemolysis, dilated sinusoids, ruptured hepatocytes, vacuolization, edema of hepatocytes, necrosis, degeneration, aggregation, and inflammation. This dye not only alters liver tissue, also induces an acute level of tissue alterations in the kidneys, such as degeneration of epithelial cells of renal tubules, shrinkage of the glomerulus, congestion, reduced lumen, degeneration of glomerulus, absence of space of bowmen, glomerulonephritis, necrosis in hematopoietic interstitial tissues and glomerulus, reduced lumen, vacuolar degeneration of renal tubules, increased per tubular space. The current study concludes that trypan blue dye released even in small amounts is found to be associated with a high incidence of cytotoxicity. Such tissue alterations in this species could be used as biomarkers for azo dyes.