Antioxidant Properties of Biologically Synthesized Silver Nanoparticles from Water Extracts of Cordyline fruticosa sp. Leaves.

Abstract

Background: The biological synthesis of nanoparticles using plants has gained attention recently, mainly due to its eco-friendly nature. Most phytochemicals and nanoparticles possess antioxidant activity, which can help neutralize harmful free radicals, paving the pathway to develop new and enhanced biomedical applications. Objective: To compare the antioxidant activity of plant extracts and silver nanoparticles (AgNPs) synthesized using leaves of five varieties of Cordyline fruticosa: candy cane (1CC), waihee rainbow (2WR), exotica (3EX), pink cascade (4PC), and pink diamond (5PD) Methods: AgNPs were synthesized from water extracts using a green approach. Morphology of synthesized 4PC-AgNPs was analyzed using scanning electron microscopy (SEM). The antioxidant activity of water extracts and AgNPs were assessed using 0.16 mM DPPH solution and assays to determine total flavonoid content (TFC), total phenolic content (TPC) and total antioxidant capacity (TAC) were carried out. One-way ANOVA analysis was conducted using MS Excel for the results obtained from each assay and Pearson correlations were calculated using SPSS to establish the relationship between TFC, TPC and TAC. Results: AgNPs were observed in 1CC, 2WR and 4PC samples. SEM analysis of 4PC-AgNPs revealed spherical nanoparticles with a diameter of about 40-50 nm. TFC, TPC, TAC and percentage DPPH activity of all synthesized nanoparticles at 100% concentration were found to be significantly higher (p<0.05) than those of 100% water extracts. All correlation values were close to 1, indicating that all results strongly correlate with each other. The highest correlation of 0.998 was observed between TPC and TAC. Conclusions: Results confirm that Cordyline fruticosa sp. leaves are a potential biomaterial for synthesis of AgNPs with enhanced antioxidant activity. The total antioxidant activity of the AgNPs might have been greatly influenced by the phenolic compounds present in the water extracts.