School of Food Science and Technology Polytechnic University, Qinggongyuan1, Ganjingzi District, Dalian 116034, Liaoning, People's Republic of China.
Food Funct. 2019 Feb 20;10(2):1123-1131. doi: 10.1039/c8fo02602e.
The effect of endogenous carbon nanoparticles from food sources is one of the hot topics in the current food research field. The relationship between the foodborne nanoparticle properties and the cytotoxic mechanism has been insufficiently studied. In this work, carbon dots (CDs) with strong fluorescence were found and purified from canned yellow croaker, and their cytotoxicity was investigated for the first time. The canned yellow croaker CDs are nearly spherical with a particle size distribution in the range of 1.8-5.8 nm. The fluorescence quantum yield of the isolated CDs is 9.7% and the maximum excitation wavelength is 340 nm, with a significant redshift phenomenon in fluorescence spectra. The surface elemental analysis showed that the composition of the canned yellow croaker CDs was C (76.42%), N (6.49%), and O (16.7%), and various functional groups are on the surface. The CDs have good stability in sodium chloride solution and the fluorescence intensity was stable within the pH value of 4 to 10. A strong fluorescence quenching effect was found upon the addition of Cu2+ and Fe3+ to the CD aqueous solution. The CDs can easily enter the interior of the live cells. Moreover, a concentration-dependent behavior of HepG2 cell viability was found when the cells were incubated with the canned yellow croaker CDs. Glycolysis and mitochondrial function analysis of HepG2 cells revealed that both the extracellular acidification rate and oxygen consumption rate significantly decreased in contrast to the normal level prior to the addition of CDs. In addition, the CDs significantly inhibited the glycolytic pathway by reducing the activity of key enzymes hexokinase and pyruvate kinase in the glycolytic pathway.
食物源内源性碳纳米粒子的影响是当前食品研究领域的热点之一。食物源纳米颗粒的性质与细胞毒性机制之间的关系还研究得不够充分。在这项工作中，从罐头黄花鱼中发现并纯化了具有强荧光的碳点（CDs），并首次研究了它们的细胞毒性。罐头黄花鱼 CDs 呈近球形，粒径分布在 1.8-5.8nm 范围内。分离出的 CDs 的荧光量子产率为 9.7%，最大激发波长为 340nm，荧光光谱有明显的红移现象。表面元素分析表明，罐头黄花鱼 CDs 的组成是 C（76.42%）、N（6.49%）和 O（16.7%），表面存在各种官能团。CDs 在氯化钠溶液中具有良好的稳定性，荧光强度在 pH 值为 4 到 10 范围内稳定。在 CD 水溶液中加入 Cu2+和 Fe3+时，发现其具有很强的荧光猝灭效应。CDs 很容易进入活细胞内部。此外，当用罐头黄花鱼 CDs 孵育 HepG2 细胞时，发现 HepG2 细胞活力呈现出浓度依赖性。HepG2 细胞糖酵解和线粒体功能分析表明，与添加 CDs 之前的正常水平相比，细胞外酸化率和耗氧量均显著降低。此外，CDs 通过降低糖酵解途径中的关键酶己糖激酶和丙酮酸激酶的活性，显著抑制了糖酵解途径。
