In vitro antioxidant and anticataractogenic potential of silver nanoparticles biosynthesized using an ethanolic extract of Tabernaemontana divaricata leaves
In vitro antioxidant and anticataractogenic potential of silver nanoparticles biosynthesized using an ethanolic extract of Tabernaemontana divaricata leaves
复制标题
DOI：
10.1016/j.biopha.2017.04.079
复制
发表时间：
2017-07-01
影响因子：
7.5
通讯作者：
Geraldine, Pitchairaj
中科院分区：
文献类型：
--
作者：
Anbukkarasi, Muniyandi;Thomas, Philip A.;Geraldine, Pitchairaj
银纳米颗粒(AgNPs)具有很大的比表面积和体积比，这赋予了它们一些独特的性质，因此在生物系统和医学中都有很大的应用价值。在这项研究中，我们评估了用竹叶乙醇提取物生物合成的AgNPs在防止实验性体外亚硒酸盐诱导的人工晶状体混浊(白内障形成)方面的潜在抗氧化作用和有效性。通过检测AgNPs对1，1-二苯基-2-苦基肼(DPPH)和过氧化氢(H_2O_2)自由基的清除能力，以及测定还原能力来评价AgNPs的体外抗氧化能力。用体外培养的Wistar大鼠晶状体在Dulbecco改良Eagle‘s培养液(DMEM)中培养24小时，观察AgNPs的抗白内障作用：第一组(阴性对照)仅在DMEM中培养；第二组(100 mU/M)单独接触亚硒酸钠；第三组(III)同时给予亚硒酸钠和白花蛇舌草提取物(250 mU/ml)；IV组同时给予亚硒酸钠和生物合成的AgNPs(125 mU/ml)；V组仅暴露于AgNPs。测定晶状体大体形态、过氧化氢酶(CAT)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GPx)、谷胱甘肽-S转移酶(GST)活性及还原型谷胱甘肽(GSH)、丙二醛(MDA)含量。在体外，银纳米粒子(平均直径为15~50 nm)呈球形，对DPPH和H_2O_2自由基具有较强的清除能力和还原能力，且具有浓度依赖性。培养的大鼠晶状体的大体形态变化为：8个对照组(I组)晶状体全部保持透明；8个亚硒酸钠未处理组(II组)全部出现致密混浊；在亚硒酸盐激发的同时给予白花蛇舌草提取物(III组)的8个晶状体中，7个(87.5%)晶状体未见混浊，仅1个(12.5%)晶状体轻度混浊；所有8个亚硒酸盐激发组(同时用AgNPs处理)的8个晶状体均未显示任何混浊；而所有8个V组晶状体(单独暴露于NPAgs)仍与对照组晶状体一样透明。与I、III、IV、V组比较，II组晶状体中CAT、SOD、GPX、GST活性及GSH含量均显著降低(p<；0.05)，而丙二醛含量则显著升高(p<；0.05)，提示II组晶状体可能存在氧化损伤，而III、IV组晶状体氧化损伤明显减轻。这些观察结果表明，白花蛇舌草叶乙醇提取物，以及利用白花蛇舌草提取物生物合成的AgNPs，在体外具有有效的抗氧化活性，并有可能防止实验性的亚硒酸盐诱导的Wistar大鼠晶状体混浊。(C)2017年爱思唯尔·马森公司。版权所有。
Silver nanoparticles (AgNPs) have been found useful in biological systems and in medicine since they possess a large surface area to volume ratio, which confers on them several unique properties. In the present study, AgNPs that had been biosynthesized using an ethanolic extract of Tabernaemontana divaricata leaf were evaluated for putative antioxidant potential and efficacy in preventing experimental in-vitro selenite-induced opacification of the ocular lens (cataractogenesis). The antioxidant potential of the AgNPs was evaluated in-vitro by looking for radical-scavenging activity on 1,1-diphenyl-2picrylhydrazyl (DPPH) and hydrogen peroxide (H2O2) free radicals as well as by determining reducing power. The anticataractogenic potential of the AgNPs was evaluated in an in-vitro model of selenite-induced cataractogenesis in five groups of Wistar rat lenses cultured in Dulbecco's modified Eagle's medium (DMEM) for 24h: Group I lenses (negative control) were cultured in DMEM alone; Group II lenses were exposed to sodium selenite alone (100 mu M); Group III lenses were exposed simultaneously to sodium selenite and the T. divaricata extract (250 mu g/ml); Group IV lenses were exposed simultaneously to sodium selenite and the biosynthesized AgNPs (125 mu g/ml); and Group V lenses were exposed to the AgNPs alone. In these lenses, gross morphological changes, as well as activities of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione-S-transferase (GST), and levels of reduced glutathione (GSH) and malondialdehyde (MDA), were determined. In-vitro, the AgNPs (which were spherical in shape with an average diameter ranging from 15 to 50 nm) showed potent and concentration-dependent radical-scavenging activity on DPPH and H2O2 free radicals as well as reducing power. The gross morphological changes seen in the cultured rat lenses were: all eight control (Group I) lenses remained transparent; dense opacification was noted in all eight selenite-challenged untreated (Group II) lenses; in selenite-challenged, simultaneously T. divaricata extract-treated (Group III) lenses, no opacification occurred in seven of eight (87.5%) lenses and only minimal opacification in one (12.5%) lens; all the eight Group IV (selenite-challenged, simultaneously AgNPs-treated) lenses did not show any opacification; and all the eight Group V lenses (exposed to AgNPs alone) remained as transparent as control lenses. The mean activities of CAT, SOD, GPx and GST, and the mean levels of GSH, were significantly (p < 0.05) lower in Group II lenses than those in Groups I, III, IV and V lenses, while the mean MDA level was significantly (p < 0.05) higher in Group II lenses than those in Groups I, III, IV and V lenses; oxidative damage possibly occurred in Group II lenses, whereas this appears to have been prevented in Groups III and IV lenses. These observations suggest that the T. divaricata leaf ethanolic extract, and also the AgNPs biosynthesized using the T. divaricata extract, possess effective in-vitro antioxidant activity and the potential to prevent experimental selenite-induced opacification in cultured Wistar rat lenses. (C) 2017 Elsevier Masson SAS. All rights reserved.