Sodium thiosulfate inhibits cisplatin-induced mutagenesis in somatic tissue of Drosophila.

The antitumor agent cisplatin was evaluated for genotoxicity in the somatic tissue of Drosophila melanogaster in combination with the nucleophilic compound sodium thiosulfate (STS). Third instar larvae transheterozygous for mwh and flr3 were grown on media containing (1) water, (2) 200 mM STS, (3) 0.05 mM cisplatin in 200 mM STS, or (4) 0.05 mM cisplatin. Wings of surviving adults were scored for the presence of twin spots and both small and large single spots; 200 mM STS was nongenotoxic in the assay. Whereas 0.05 mM cisplatin significantly induced all three endpoints, 0.05 mM cisplatin in combination with 200 mM STS was found to have no genotoxic activity. Hence, STS possessed antimutagenic activity in the wing-spot assay and completely inhibited cisplatin-induced mutagenesis and mitotic recombination.