Biological assessment of Taraxacum officinale hydroethanolic root extract green synthesized gold nanoparticles

The present study reports the multidimensional applicability of green synthesized gold nanoparticles (AuNPs) using Taraxacum officinale hydroethanolic root extract (ToR-EtOH). ToR-EtOH was initially characterized for its phytochemical composition through GC-MS analysis. The green synthesized gold nanoparticles (ToR-AuNPs) from ToR-EtOH were further characterized using UV-Vis spectroscopy, dynamic light scattering (DLS), electron microscopy and FT-IR. Subsequently, both ToR-EtOH and ToR-AuNPs were evaluated for their anti-oxidant and anti-bacterial potential. ToR-EtOH showed presence of various bioactive compounds primarily including flavonoids, polyphenols and phenolic acids, phytosterols and triterpenoids among others. The biosynthesized ToR-AuNPs exhibited a characteristic peak at ~ 555 nm indicating plasmon resonance band of typical AuNPs. The Z_avg and zeta (ζ)-potential of ToR-AuNPs was found to be 90 nm and - 12.24 ± 0.89 mV respectively. Electron microscopy further confirmed 40 ± 2.82 nm size of ToR-AuNPs. Subsequently, FT-IR investigation elucidated broadening of peak at ∼3200 cm^-1 indicating successful reduction of Au⁺ to Au⁰ by ToR-EtOH. Both ToR-EtOH and ToR-AuNPs showed dose-dependent antioxidant efficacy with IC₅₀ values of ~180 ± 2.26 µg/mL in comparison to ascorbic acid ~30.6 ± 1.4 µg/mL. Intrigungly, a significant (p<0.001) elevation in anti-oxidant and anti-bacterial activities was observed between ToR-EtOH and ToR-AuNPs. Summarily, the study for the first time reports the successful green synthesis of AuNPs using ToR-EtOH. It also highlights the biomedical suitability of synthesized ToR-AuNPs with significantly higher anti-oxidant and anti-bacterial efficacy. Nevertheless, further explorative studies are warranted to further establish the efficacy of ToR-AuNPs in suitable in vitro and in vivo models.