Mangalampalli Bhanuramya, Dumala Naresh, Grover Paramjit
Toxicology Unit, Pharmacology and Toxicology Division, CSIR - Indian Institute of Chemical Technology, Hyderabad, Telangana 500007, India; Academy of Scientific and Innovative Research, CSIR - Indian Institute of Chemical Technology, Hyderabad, Telangana 500007, India.
Toxicology Unit, Pharmacology and Toxicology Division, CSIR - Indian Institute of Chemical Technology, Hyderabad, Telangana 500007, India; Academy of Scientific and Innovative Research, CSIR - Indian Institute of Chemical Technology, Hyderabad, Telangana 500007, India.
J Environ Sci (China). 2018 Apr;66:125-137. doi: 10.1016/j.jes.2017.05.012. Epub 2017 May 12.
Allium cepa bioassay had been used from decades for the assessment of toxicants and their harmful effects on environment as well as human health. Magnesium oxide (MgO) particles are being utilized in different fields. However, reports on the adverse effects of MgO nanoparticles on the environment and mankind are scarce. Hence, the toxicity of MgO particles is of concern because of their increased utilization. In the current study, A. cepa was used as an indicator to assess the toxicological efficiency of MgO nano- and microparticles (NPs and MPs) at a range of exposure concentrations (12.5, 25, 50, and 100μg/mL). The toxicity was evaluated by using various bioassays on A. cepa root tip cells such as comet assay, oxidative stress and their uptake/internalization profile. Results indicated a dose dependent increase in chromosomal aberrations and decrease in mitotic index (MI) when compared to control cells and the effect was more significant for NPs than MPs (at p<0.05). Comet analysis revealed that the Deoxyribonucleic acid (DNA) damage in terms of percent tail DNA ranged from 6.8-30.1 over 12.5-100μg/mL concentrations of MgO NPs and was found to be significant at the exposed concentrations. A significant increase in generation of hydrogen peroxide and superoxide radicals was observed in accordance with the lipid peroxidation profile in both MgO NPs and MPs treated plants when compared with control. In conclusion, this investigation revealed that MgO NPs exposure exhibited greater toxicity on A. cepa than MPs.
几十年来，洋葱生物测定法一直被用于评估有毒物质及其对环境和人类健康的有害影响。氧化镁（MgO）颗粒正被应用于不同领域。然而，关于MgO纳米颗粒对环境和人类不利影响的报道却很少。因此，由于MgO颗粒的使用增加，其毒性受到关注。在本研究中，洋葱被用作指标，以评估一系列暴露浓度（12.5、25、50和100μg/mL）下MgO纳米颗粒和微米颗粒（NP和MP）的毒理学效应。通过对洋葱根尖细胞进行多种生物测定，如彗星试验、氧化应激及其摄取/内化情况，来评估毒性。结果表明，与对照细胞相比，染色体畸变呈剂量依赖性增加，有丝分裂指数（MI）降低，且NP的影响比MP更显著（p<0.05）。彗星分析显示，在12.5-100μg/mL的MgO NP浓度范围内，尾DNA百分比表示的脱氧核糖核酸（DNA）损伤范围为6.8-30.1，且在暴露浓度下具有显著性。与对照相比，在MgO NP和MP处理的植物中，根据脂质过氧化情况观察到过氧化氢和超氧自由基的生成显著增加。总之，本研究表明，暴露于MgO NP对洋葱的毒性比MP更大。
