Toxic effects of gentamicin in the third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ)Bg9

Abstract

Gentamicin is an aminoglycoside antibiotic and is used to treat various Gram negative bacteria. Due to its thermal stability it is useful for the preparation of culture media for various cell lines and microorganisms. It has been reported as ototoxic and nephrotoxic in adult humans. In the present study the toxic effects of gentamicin were studied in the third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ)Bg⁹. The third instar larvae were exposed to a wide range of doses, i.e. 60, 70, 80, 90 and 100 μg ml⁻¹ of gentamicin for 6, 12, 24 and 48 hours. The exposure of larvae to the above doses for 6 and 12 hours did not show any toxic effects. The exposure of larvae to 80, 90 and 100 μg ml⁻¹ of gentamicin for 24 hours and 70, 80, 90 and 100 μg ml⁻¹ of gentamicin for 48 hours showed a dose-dependent toxic effect. The dose of 60 μg ml⁻¹ did not show any toxic effects and hence can be suggested as the No Observed Adverse Effect Level (NOAEL). The results suggest that gentamicin is toxic at higher doses and longer duration of exposure.