Silver nanoparticles (AgNPs) previously synthesised using leaf (AgNP-L) and stem (AgNP-S) extracts of Clinacanthus nutans (C. nutans) were tested to evaluate antimicrobial, antioxidant, and cytotoxicity activities. The AgNPs showed good inhibition against bacteria, but not fungi. The inhibition results showed the highest activity against Staphylococcus aureus (S. aureus) with 11.35 mm (AgNP-L) and 11.52 mm (AgNP-S), while the lowest inhibition was against Escherichia coli (E. coli) with 9.22 mm (AgNP-L) and 9.25 mm (AgNP-S) in the disc diffusion method. The same trend of results was noted in the well diffusion method. The IC₅₀ of AgNP-L and AgNP-S in 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays was 417.05 μg/mL and 434.60 μg/mL, as well as 304.31 μg/mL and 326.83 μg/mL, respectively. Ferric reducing power (FRAP) assay showed that AgNP-L [872.389 μmol/L Fe(II)] and AgNP-S [612.770 μmol/L Fe(II)] exhibited significantly ( < 0.05) greater antioxidant activities than leaf extract (CNL) [152.260 μmol/L Fe(II)] and stem extract (CNS) [110.445 μmol/L Fe(II)] of C. nutans. The AgNPs were also proven to possess cytotoxic effects on the breast (MCF-7), cervical (HeLa), and colon (HT-29) cancer cells in a dose-dependent manner. AgNP-S and AgNP-L showed significantly ( < 0.05) higher cytotoxicity against MCF-7 (117.43 μg/mL) and HT-29 (78.47 μg/mL), respectively. In conclusion, the biosynthesised AgNPs from aqueous extract leaves and stem of C. nutans have demonstrated promising potential towards antioxidant, antimicrobial, and cytotoxicity activities.

中文翻译：

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Clinacanthus nutans 的生物银纳米颗粒作为具有抗菌和细胞毒性作用的抗氧化剂


之前使用Clinacanthus nutans ( C. nutans ) 的叶 (AgNP-L) 和茎 (AgNP-S) 提取物合成的银纳米粒子 (AgNP) 进行了测试，以评估抗菌、抗氧化和细胞毒性活性。 AgNPs 对细菌表现出良好的抑制作用，但对真菌没有抑制作用。抑制结果显示，11.35 mm (AgNP-L) 和 11.52 mm (AgNP-S) 对金黄色葡萄球菌( S. aureus ) 的活性最高，对大肠杆菌( E. coli ) 的抑制活性最低，9.22 mm (AgNP) -L) 和 9.25 mm (AgNP-S)，采用圆盘扩散法。在井扩散法中也发现了相同的结果趋势。 AgNP-L 和 AgNP-S 在 2,2-二苯基-1-三硝基苯肼 (DPPH) 和 2,2'-连氮基-双 (3-乙基苯并噻唑啉-6-磺酸) (ABTS) 测定中的 IC ₅₀为 417.05 μ g/mL和434.60μg /mL，以及304.31μg /mL和326.83μg /mL分别。三价铁还原力 (FRAP) 测定表明，AgNP-L [872.389 μ mol/L Fe(II)] 和 AgNP-S [612.770 μ mol/L Fe(II)] 的抗氧化活性显着高于叶片 (< 0.05) C. nutans的提取物 (CNL) [152.260 μ mol/L Fe(II)] 和茎提取物 (CNS) [110.445 μ mol/L Fe(II)]。 AgNP 还被证明对乳腺癌 (MCF-7)、宫颈癌 (HeLa) 和结肠癌 (HT-29) 癌细胞具有剂量依赖性的细胞毒性作用。 AgNP-S 和 AgNP-L 对 MCF-7 (117.43 μ g/mL) 和 HT-29 (78.47 μ g/mL) 分别表现出显着更高的细胞毒性 (< 0.05)。总之，从水提物叶和茎中生物合成的 AgNPs 。 Nutans 已表现出抗氧化、抗菌和细胞毒性活性的巨大潜力。