Department of Bioscience, COMSATS University, Islamabad, Pakistan.
Microbial Biotechnology Laboratory, Department of Zoology, The University of Azad Jammu and Kashmir, King Abdullah Campus, Muzaffarabad, Pakistan.
PLoS One. 2023 Aug 7;18(8):e0282485. doi: 10.1371/journal.pone.0282485. eCollection 2023.
The current study is designed to synthesize gold nanoparticles using Ajuga bracteosa extract, which is a highly known medicinal herb found in the northern Himalayas. The synthesized gold nanoparticles were initially characterized by UV-Vis spectrophotometer, SEM, FTIR, pXRD, and, GC-MS. Antibacterial efficacy of A. bracteosa extract, AuNps, and AuNps-free supernatant activity was checked against highly pathogenic clinical isolates of Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa via agar well diffusion method, assuming that supernatant might have active compounds. The Nps-free supernatant showed the maximum antibacterial activity against E. coli (20.8±0.3 mm), Staphylococcus aureus (16.5±0.5), and Pseudomonas aeruginosa (13±0.6). While green synthesized AuNps showed effective antibacterial activity (Escherichia coli (16.4±0.3mm), Staphylococcus aureus (15.05±0.5mm), and Pseudomonas aeruginosa (11.07±0.6mm)) which was high compared to A. bracteosa extract. Anticancer activity was assessed by MTT assay on U87 and HEK293 cell lines. Aj-AuNps have an antigrowth effect on both the cell lines however Aj-AuNps-free supernatant which was also evaluated along with the Aj-AuNps, showed high toxicity toward HEK293 cell line compared to U87. Further, the GC-MS analysis of supernatant showed the presence of resultant toxic compounds after the reduction of gold salt, which include Trichloromethane, Propanoic acid, 2-methyl-, methyl ester, Methyl isovalerate, Pentanoic acid, 2-hydroxy-4-methyl-, Benzene-propanoic acid, and alpha-hydroxy. Based on the observation small molecular weight ligands of Ajuga bracteosa were analyzed in-silico for their binding efficacy towards selected membrane proteins of our target pathogens. RMSD is also calculated for the best docked protein ligand pose. The results revealed that among all listed ligands, Ergosterol and Decacetylajugrin IV have high virtuous binding affinities towards the membrane proteins of targeted pathogens. The current findings revealed that the Aj-AuNps are good antibacterial as well as anticancerous agents while the Nps-free supernatant is also exceedingly effective against resistant pathogens and cancer cell lines.
本研究旨在利用 Ajuga bracteosa 提取物合成金纳米粒子，Ajuga bracteosa 是一种在喜马拉雅山北部广泛应用的药用植物。合成的金纳米粒子最初通过紫外-可见分光光度计、SEM、FTIR、pXRD 和 GC-MS 进行表征。通过琼脂孔扩散法检测 Ajuga bracteosa 提取物、AuNps 和 AuNps 无上清液对高度致病性临床分离株大肠杆菌、金黄色葡萄球菌和铜绿假单胞菌的抑菌效果，假设上清液可能含有活性化合物。无 Nps 的上清液对大肠杆菌（20.8±0.3mm）、金黄色葡萄球菌（16.5±0.5）和铜绿假单胞菌（13±0.6）表现出最大的抗菌活性。而绿色合成的 AuNps 表现出有效的抗菌活性（大肠杆菌（16.4±0.3mm）、金黄色葡萄球菌（15.05±0.5mm）和铜绿假单胞菌（11.07±0.6mm）），与 Ajuga bracteosa 提取物相比，这一效果更高。通过 MTT 法在 U87 和 HEK293 细胞系上评估抗癌活性。Aj-AuNps 对两种细胞系均有生长抑制作用，而 Aj-AuNps 无上清液也与 Aj-AuNps 一起进行了评估，与 U87 相比，对 HEK293 细胞系表现出更高的毒性。此外，上清液的 GC-MS 分析表明，金盐还原后存在有毒化合物，包括三氯甲烷、2-甲基丙酸甲酯、2-羟基-4-甲基戊酸、苯丙酸和 alpha-羟基。基于观察，分析了 Ajuga bracteosa 的小分子配体，以研究其对选定靶病原体膜蛋白的结合效力。还计算了 RMSD 以获得最佳对接蛋白配体构象。结果表明，在所列出的配体中，麦角甾醇和去乙酰阿角亭 IV 对靶病原体的膜蛋白具有较高的结合亲和力。目前的研究结果表明，Aj-AuNps 既是良好的抗菌剂，也是抗癌剂，而无 Nps 的上清液对耐药病原体和癌细胞系也具有极高的疗效。
