Research Institute of Biotechnology & Medical Converged Science, Dongguk University, Seoul, Gyeonggi-do 10326, Republic of Korea.
Department of Biotechnology, Yeungnam University, Gyeongsan, Republic of Korea.
Int J Nanomedicine. 2019 Jul 2;14:4741-4754. doi: 10.2147/IJN.S210517. eCollection 2019.
(L.) Lam.(Ib) has high content of various beneficial nutrients which helps in improving and maintaining human health. It is well known as a functional food and also a valuable source of unique natural products. It contains various phenolic and flavonoid bioactive compounds.
In this study, using the outer peel of two varieties of Ib : Korean red skin sweet potato and Korean pumpkin sweet potato, silver nanoparticles (AgNPs) were synthesized (termed Ib1-AgNps and Ib2-AgNps), respectively. Characterization of Ib1-AgNPs and Ib2-AgNPs was carried out through scanning electron microscopy, Fourier-transform infrared (FT-IR) spectroscopy, energy-dispersive X-ray analysis, X-ray powder diffraction and UV-Vis spectroscopy. Further, the bio-potential of the synthesized AgNPs was investigated by antidiabetic (α-glucosidase assay), antioxidant (free radical scavenging assays), antibacterial (disc diffusion method) and cytotoxicity assays (cell viability against HepG2 cells).
FT-IR spectroscopy revealed the contribution of bioactive compounds existing in Ib1 and Ib2 extracts, in the biosynthesis and equilibrium of the AgNPs. Although the Ib2-AgNPs had a higher atomic percentage of Ag in comparison with Ib1-AgNPs, in the antidiabetic assay, the inhibition percentage of α-glucosidase was higher for AgNPs of Ib1 than Ib2, at all three concentrations examined. From the cytotoxicity results, HepG2 cancer cells were more sensitive to the Ib1-AgNPs in comparison to the Ib2-AgNPs-treated HepG2 cells. The antioxidant prospective was higher in Ib2-AgNPs than Ib1-AgNPs. Moreover, the Ib2-AgNPs showed inhibitory action against all five tested pathogenic bacteria, producing an inhibition zone of 8.74-11.52 mm while Ib1-AgNPs had an inhibitory effect on four of them, with an 8.67-11.23 (mm) inhibition zone.
Overall, the results concluded that the Ib2-AgNPs exhibited relatively higher functional activity than Ib1-AgNPs, which might be credited to the greater abundance of bioactive compounds existing in Ib2 extract that acted as reducing as well as capping agents in the synthesis of Ib2-AgNPs. Overall, the current study highlights a novel cost-effective and eco-friendly AgNPs synthesis using food waste peels with biocompatibility and could be potentially utilized in biomedical and pharmaceutical industries.
（L.）Lam.（Ib）含有丰富的各种有益营养物质，有助于改善和维持人类健康。它是一种众所周知的功能性食品，也是独特天然产品的宝贵来源。它含有各种酚类和类黄酮生物活性化合物。
在这项研究中，使用两种 Ib 的外果皮：韩国红皮甘薯和韩国南瓜甘薯，分别合成了银纳米粒子（AgNPs）（分别称为 Ib1-AgNps 和 Ib2-AgNps）。通过扫描电子显微镜、傅里叶变换红外（FT-IR）光谱、能量色散 X 射线分析、X 射线粉末衍射和紫外可见光谱对 Ib1-AgNPs 和 Ib2-AgNPs 进行了表征。此外，通过抗糖尿病（α-葡萄糖苷酶测定）、抗氧化（自由基清除测定）、抗菌（圆盘扩散法）和细胞毒性测定（对 HepG2 细胞的细胞活力）研究了合成 AgNPs 的生物潜力。
FT-IR 光谱表明，Ib1 和 Ib2 提取物中的生物活性化合物在 AgNPs 的生物合成和平衡中发挥了作用。尽管 Ib2-AgNPs 中的 Ag 原子百分比高于 Ib1-AgNPs，但在抗糖尿病测定中，所有三种浓度下，Ib1-AgNPs 对α-葡萄糖苷酶的抑制率均高于 Ib2-AgNPs。从细胞毒性结果来看，与 Ib2-AgNPs 处理的 HepG2 细胞相比，HepG2 癌细胞对 Ib1-AgNPs 更为敏感。Ib2-AgNPs 的抗氧化前景高于 Ib1-AgNPs。此外，Ib2-AgNPs 对所有五种测试的致病菌均表现出抑制作用，产生 8.74-11.52mm 的抑制区，而 Ib1-AgNPs 对其中四种致病菌具有抑制作用，抑制区为 8.67-11.23（mm）。
总体而言，结果表明 Ib2-AgNPs 表现出相对较高的功能活性，这可能归因于 Ib2 提取物中存在的更多生物活性化合物，这些化合物在 Ib2-AgNPs 的合成中既充当还原剂又充当封端剂。总的来说，本研究强调了一种使用食品废料皮进行新型、经济高效且环保的 AgNPs 合成的方法，具有生物相容性，可潜在用于生物医学和制药行业。
