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.
