Assessment of the toxic effects of silane quaternary ammonium compounds with various chain lengths and structures on Drosophila melanogaster

The global consumption of disinfectants, including alcohol-based and alcohol-free products, has increased dramatically since the onset of the COVID-19 pandemic. Thus, the toxic potential of such products and their mixtures remains unclear. Furthermore, shortcomings of raw materials, including alcohol, have been reported. In this context, to limit the side effects and potential risks of using disinfectants and to ensure a friendly product without suffering a sudden shortcoming in materials when the world faces a new challenge or pandemic, we attempted to synthesize a new disinfectant, silane quaternary ammonium compounds (Si-QACs). In the present study, we assessed the genotoxic, cytotoxic, apoptotic, and neurotoxic potential of alcohol-free novel synthesized disinfectants in Drosophila melanogaster as a model organism. Novel disinfectants were synthesized based on the reaction of the silane group with quaternary ammonium compounds with different structures and chain lengths (12 C-18 C). The antimicrobial activity of Si-QACs was evaluated using the MIC test. The genotoxic potential was assessed using SMART (mutation and/or recombination) and comet (DNA strand breaks) assays. Furthermore, the cytotoxic potential was evaluated using the trypan blue test, and the apoptotic potential was evaluated by measuring caspases activities and oxidative stress using TAS/TOS assay. To elucidate the mechanism of DNA repair, the expression of 36 genes involved in different DNA repair pathways was measured using RT2-PCR. Several assays, including crawling, pupal position, climbing, and sensitivity, have been conducted in Drosophila to understand the neurotoxic potential of Si-QACs. In the SMART assay, a potential mutation of Si-QAC-1 was recorded at all concentrations, whereas only the highest concentration of Si-QAC-2 (300 %) was associated with a risk of mutation. No significant changes were observed in the remaining Si-QACs. However, according to comet assay results, DNA strand breaks were recorded in Si-QAC-1 (100 %), Si-QAC-3 (25 %, 50 %, 100 %, and 200 %), Si-QAC-4 (50 %, 200 %, and 300 %), and Si-QAC-5 (50 %, 100 %, 200 %, and 300 %), and no significant change was observed in Si-QAC-2. Further, no cytotoxic potential has been recorded for Si-QAC-2, however, significant damage has been reported in the midgut of Drosophila larvae exposed to Si-QAC-1 (200 % and 300 %), Si-QAC-3 (100 %, 200 %, and 300 %), Si-QAC-4 (100 % and 200 %), and Si-QAC-5 (300 %). Caspase activities increased in all Si-QACs at all concentrations, except Si-QAC-1 (50 %). According to RT2-PCR analysis, Si-QAC-2 (25 %) upregulated most of the genes involved in DNA repair, followed by Si-QAC-3 (300 %), whereas Si-QAC-1 (300 %) downregulated the major genes. All Si-QACs caused oxidative stress. In the crawling assay, the distance crossed by larvae exposed to Si-QAC-3 (300 %) increased compared to the control group, and thus, the speed. In the climbing assay, no defects were reported for any Si-QACs. In the pupal position assay, the larvae exposed to Si-QAC-1 were located far from the medium. In the sensitivity assay, Si-QAC-1 (25 %), Si-QAC-2 (200 %), and Si-QAC-3 (50 %, 100 %, 200 %, and 300 %) affected larvae thermoreceptors. In conclusion, Si-QAC-2 seems to be a promising disinfectant, where only the highest concentrations were able to induce some damage; however, further studies are needed to ensure the safety of consumers before the release of the disinfectant to the market.