Insights into the toxic effects of moxifloxacin in Allium cepa through multiparametric experimental and in silico analyses
摘要
In this study, the cytogenetic and biochemical effects of moxifloxacin (MOX), a fourth-generation fluoroquinolone antibiotic, on Allium cepa L., a non-target plant model, were investigated using a combination of experimental and in silico approaches. Onion roots were exposed to MOX at concentrations of 15, 29, and 57 µg/L. Genotoxicity was assessed using the mitotic index (MI), micronucleus (MN), chromosomal aberrations (CAs), and the Comet assay. The findings showed that MOX reduced mitotic activity in a dose-dependent manner (by 21% in the highest dose group) and significantly increased the frequency of MNs and CAs. In addition, marked increases were observed in CAs such as loose fragment, bridges, and multipolar anaphase. Comet assay results revealed a significant increase in DNA damage, the tail DNA percentage rose from 2.60% to 60.9%, while the tail moment increased from 0.05 to 15.82. Biochemical analyses showed that MOX exposure triggered oxidative stress responses. While malondialdehyde (MDA) levels increased by up to 2.06-fold, superoxide dismutase (SOD) and catalase (CAT) activities increased by 1.84-fold and 3.23-fold, respectively. In contrast, a dose-dependent decrease in photosynthetic pigment levels was observed in the highest dose group, chlorophyll a and b contents decreased by 47.3% and 61.8%, respectively, compared to the control. Molecular docking analyses indicated that MOX can interact specifically with β-tubulin and B-DNA. When the findings were evaluated collectively, it was concluded that MOX could negatively affect DNA integrity, chromosomal stability, and oxidative balance, and that it provides significant contributions to the assessment of the ecotoxicological risks of pharmaceutical contaminants in plants.