The objective of the present work was to improve the biological activity of Padina gymnospora. In the current study, silver chloride nanoparticles have been synthesized using the aqueous extract of Padina gymnospora and further characterized by ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy, x-ray powder diffraction, scanning electron microscopy, energy dispersive spectroscopy, transmission electron microscopy and atomic force microscope. Further, the hemolytic activity and eco-toxicity of silver chloride nanoparticles analyzed. The synthesized silver chloride nanoparticles were found to be mono-dispersed and spherical with an average size of 11.5–32.86 nm. The particles showed an anticancer effect in a dose-dependent manner against breast cancer cell line (MCF-7 cell lines) (IC₅₀=31.37 μg ml⁻¹). In addition, it showed the larvicidal activity against Aedes aegypti at a lower dose (3.92 μg ml⁻¹) than that of the aqueous extract (13.01 μg ml⁻¹). Nanoparticles also exhibited greater antimicrobial activity for both bacterial and fungal pathogens. The synthesized silver chloride nanoparticles showed a maximum zone of inhibition, i.e., 31 mm for Candida albicans followed and 27 mm for vancomycin resistance Enterococcus faecalis.The results suggest the possible use of synthesized silver nanoparticles with P. gymnospora as therapeutic agent for breast cancer, dengue vector control and as antimicrobial agent.

本工作的目的是改善Padina Gymnospora的生物活性。在当前的研究中，已经使用Padina Gymnospora的水提取物合成了氯化银纳米颗粒。并进一步以紫外-可见光谱，傅里叶变换红外光谱，X射线粉末衍射，扫描电子显微镜，能量色散光谱，透射电子显微镜和原子力显微镜为特征。此外，分析了氯化银纳米颗粒的溶血活性和生态毒性。发现合成的氯化银纳米粒子是单分散的球形，平均大小为11.5–32.86 nm。所述颗粒表现出对乳腺癌细胞系（MCF-7细胞系）以剂量依赖的方式（IC抗癌作用₅₀ = 31.37 μ克毫升^-1）。此外，它表现出抗的杀幼虫活性的埃及伊蚊在较低剂量（3.92 μ克毫升^-1）比水提取物（13.01 μ克毫升^-1）。纳米颗粒还对细菌和真菌病原体均表现出更大的抗菌活性。合成的氯化银纳米颗粒显示出最大的抑制区域，即白色念珠菌紧随其后为31 mm，对万古霉素耐药的粪肠球菌为27 mm 。结果表明，合成的银纳米颗粒可与体育裸孢菌一起用作乳腺癌的治疗剂，登革热媒介控制和用作抗菌剂。