Effect of Tangeretin against Ethyl Methanesulfonate Induced Toxicity in the third Instar Larvae of Transgenic Drosophila melanogaster (hsp70-lacZ Bg9)

Background: Tangeretin is a polymethoxylated flavone naturally found in the peels of Citrus reticulata. Ethyl methanesulfonate (EMS) is a well-known alkylating agent recognized for its mutagenic, genotoxic, and potential carcinogenic properties. The expression of Heat Shock Protein 70 (Hsp70) in third-instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ) Bg9 has been widely used to investigate the effects of various environmental and chemical stressors. The present study aimed to evaluate the protective effect of Tangeretin against EMS-induced toxicity in third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ) Bg9. Methods: Third-instar larvae were exposed to a diet containing 25 µM EMS alone and in combination with 20, 40, 60, and 80 µM of Tangeretin for 24 hours. Following the exposure, the larvae were subjected to a series of biochemical and cytological analyses, including the ONPG assay, Xgal staining, trypan blue exclusion test, assessments of oxidative stress markers, caspase-3 and caspase-9 activity assays, and the comet assay. Results: Co-exposure of larvae to EMS and Tangeretin resulted in a dose-dependent and significant reduction in β-galactosidase activity, tissue damage, thiobarbituric acid reactive substances (TBARS), protein carbonyl content, Glutathione-S-Transferase (GST) activity, catalase and superoxide dismutase (SOD) activities, monoamine oxidase (MAO) activity, caspase-3 and caspase- 9 activities, and DNA damage. Conversely, there was a significant increase in glutathione (GSH) levels, delta-aminolevulinic acid dehydratase (ALAD) activity, and acetylcholinesterase (AChE) activity, indicating a protective response. Conclusion: Tangeretin, a natural plant-derived compound, exhibits multiple biological activities and demonstrates substantial protective effects against EMS-induced toxicity. These findings suggest that Tangeretin effectively preserves striatonigral integrity and function, supporting its potential as a neuroprotective agent.