Bioengineered gold nanoparticles using Cynodon dactylon extract and its cytotoxicity and antibacterial activities

In this study, simple and green route approach was applied for the synthesis gold nanoparticles (AuNPs) containing an aqueous extract of Cynodon dactylon L. Pers., (C. dactylon). The synthesized AuNPs were characterized using spectral and microscopic analysis. The changes in the color pattern were observed upon synthesis by UV-vis spectrophotometer with a peak of 530 nm. The FT-IR, XRD, SEM, and TEM were used to analyze the crystal nature and morphology of the green synthesized AuNPs. The C. dactylon-loaded AuNPs in different concentrations (0.625-100 μg/ml) were used to assess cytotoxicity activity against MCF-7 cell line and where the IC₅₀ was found to be 31.34 μg/ml by MTT assay. The C. dactylon-AuNPs were significantly increased reactive oxygen species (ROS) generation, DNA fragmentation, and mitochondrial membrane changes observed by dichlorodihydroflurescenin diacetate (DCFH-DA), 4',6-diamidino-2-phenylindole (DAPI), Rhodamine-123, and acridine orange (AO)/ethidium bromide (EtBr) staining assay. Besides the microbial study revealed that C. dactylon-AuNPs exhibited significant antibacterial activity against clinically isolated pathogenic bacteria such as Enterobacter cloacae, Staphylococus Haemolytics, Staphylococcus petrasii subsp. Pragensis and Bacillus cereus with a zone of inhibition 13, 12, 13 and 12 mm, respectively. It could be concluded that C. dactylon has the ability to be involved in the biosynthesis of AuNPs, and the pharmacological studies proved the promising cytotoxic effect on MCF-7 cell line and pathogenic bacterial species.