Zoology Department, Faculty of Science, Tanta University, 31527 Tanta, Egypt.
Zoology Department, Faculty of Science, Tanta University, 31527 Tanta, Egypt; Centre of Integrative Bee Research (CIBER), Entomology Department, University of California at Riverside, Riverside, CA 92507, USA.
Sci Total Environ. 2019 Feb 15;651(Pt 1):1356-1367. doi: 10.1016/j.scitotenv.2018.09.311. Epub 2018 Sep 24.
Beside many beneficial applications in industry, agriculture and medicine, nanoparticles (NPs) released into the environment might cause adverse effects. In the present study, effects of exposure to sublethal concentrations of PbO and CdO NPs, either separately or in combination on honey bee (A. mellifera) workers were assessed. Honey bee workers were fed sugar syrup contained (20% of LC) of CdO (0.01 mg ml) and PbO (0.65 mg ml) NPs either separately or combined for nine days under laboratory conditions. Control bees were fed 1.5 M sucrose syrup without NPs. Effects on histological and cellular structure of mid gut cells were investigated using light and electron microscope. Percentages of incidence of apoptosis or/and necrosis in mid gut cells were also quantified by use of flow cytometry. Rapture of the peritrophic membrane (PM) was among the most observed histopathological alteration in bees fed sugar syrup contained CdO NPs separately or combined with PbO NPs. Common cytological alterations observed in epithelial cells were irregular distribution or/and condensation of nuclear chromatin, mitochondrial swelling and lysis, and rough endoplasmic reticulum (rER) dilation, fragmentation, and vesiculation and were quite similar in all treated groups compared to control. The greatest incidence (%) of necrosis was observed in bees fed the diet that contained CdO NPs alone. The greatest % of both apoptosis and necrosis was observed in bees fed sugar syrup spiked with sublethal concentrations of both metal oxide NPs. Joint action of the binary mixture of Cd and Pb oxide NPs on honey bees was concluded to be antagonistic. Collectively, exposure of honey bees to these metal oxide NPs even at sublethal concentrations will adversely affect viability of the colony and further studies are still required to determine the effects of these metal oxide NPs on behavior and pollination ecology of honeybees.
除了在工业、农业和医学上的许多有益应用外，释放到环境中的纳米颗粒（NPs）可能会产生不良影响。本研究评估了亚致死浓度的 PbO 和 CdO NPs 单独或联合暴露对蜜蜂（A. mellifera）工蜂的影响。在实验室条件下，蜜蜂工蜂连续 9 天喂食含有 20%（LC）CdO（0.01mg/ml）和 PbO（0.65mg/ml）NPs 的糖水，或单独喂食或联合喂食。对照蜂喂食不含 NPs 的 1.5M 蔗糖糖浆。使用光镜和电子显微镜研究了中肠细胞的组织学和细胞结构变化。还通过流式细胞术定量分析了中肠细胞凋亡或/和坏死的百分比。单独喂食或联合喂食 CdO NPs 的蜜蜂中观察到的最明显的组织病理学改变之一是围食膜（PM）的捕获。在上皮细胞中观察到的常见细胞学改变是核染色质不规则分布或/和浓缩、线粒体肿胀和溶解，以及粗面内质网（rER）扩张、碎裂和囊泡化，与对照组相比，所有处理组都非常相似。单独喂食 CdO NPs 的蜜蜂中观察到的坏死发生率最高（%）。喂食含有两种金属氧化物 NPs 的亚致死浓度的糖水的蜜蜂中观察到的凋亡和坏死百分比最大。Cd 和 Pb 氧化物 NPs 二元混合物对蜜蜂的联合作用被判定为拮抗作用。综上所述，即使在亚致死浓度下，蜜蜂暴露于这些金属氧化物 NPs 也会对蜂群的生存能力产生不利影响，仍需要进一步研究来确定这些金属氧化物 NPs 对蜜蜂行为和授粉生态学的影响。
