Coumarin-Based Noncytotoxicity Fluorescent Dye for Tracking Actin Protein in In-Vivo Imaging

Drosophila shares maximum homology with the human disease-causing genes and thus has been employed to evaluate the toxicity of numerous compounds. Further, its distinguishable developmental stages, easy rearing, and short lifespan make it a perfect model organism to study toxicological properties of any new compound. The current study evaluates the toxic effect of a coumarin-based organic fluorescent dye, 7-hydroxy-4-methyl-8-((4-(2-oxo-2H-chromen-3-yl)­thiazol-2-ylimino)­methyl)-2H-chromen-2-one (CTC), using Drosophila melanogaster as a model organism by studying different behavioral, screening, and staining techniques using Oregon-R flies. For toxicity assessment, one control fly group was compared with various flies that had been subjected to fed CTC dye orally of different concentrations (0.5, 1, 2.5, and 5 μg/mL). The 3rd instar larvae were checked for the larvae crawling assay. The crawling assay demonstrates that the speed and path of the treated larvae are almost equal to the control ones, which signifies the non-neurotoxic property of CTC. Trypan blue assay further suggested that the dye does not cause any major damage to the gut. Phalloidin staining revealed that the actin composition remains unaltered even after the CTC treatment, while the DAPI staining experiment indicates that CTC does not cause any nuclear damage to fly gut cells. However, at a concentration of 5 μg/mL, CTC causes developmental delay. The flies hatched after larval treatment of CTC do not show any structural defects, suggesting clearly that CTC is also nongenotoxic to Drosophila. The current studies propose CTC as a noncytotoxic and nongenotoxic dye to track actin protein in the model organism D. melanogaster.