Extraction, biosynthesis, and characterization of silver nanoparticles for its enhanced applications of antibacterial activity using the Silybum marianum Linn. plant

Silybum marianum commonly known as milk thistle is an important medicinal plant used for dyslipidemia, hyperlipidemia, cAMP phosphodiesterase inhibition, leukotriene synthesis inhibition, diabetes, chronic hepatitis, antipsoriatic activity, etc., based on current medicinal properties plant focused for the bioactive compound identification through GC-MS analysis, silver nanoparticle (AgNP) synthesis, characterization of milk thistle ethanol leaf extract, biological application of nanoparticles for antibacterial activity, it is an eco-friendly approach. In methodology, the GC-MS secondary metabolites are analyzed; the AgNPs were characterized by various analytical techniques such as UV-visible spectrophotometer (UV-spectrum), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), energy-dispersive X-rays (EDX), and atomic force microscopy (AFM). In results, the 10 major bioactive compounds were identified through GC-MS; UV-visible spectrum analysis showed AgNPs observed at 414 nm; FT-IR revealed the O-H stretching functional group presence, with high peak intensity 3422 cm(-1) (graphene oxide) noticed. The AgNP particle size 10-20 nm was observed in SEM; TEM showed the synthesized AgNP spherical shape with an average diameter of 20-50 nm. The SAED confirmed that the AgNPs have highly crystalline nature; the XRD exhibited four Bragg reflections at 38.45 (111), 46.35 (200), 64.75 (220), and 78.05 (301); EDX revealed that the elemental synthesis of AgNPs was 8.79 nm on energy metabolism. At AFM, AgNPs showed irregular shapes and sizes that ranged 42-52 nm. The synthesized AgNPs exhibited significant antibacterial activity against Escherichia coli, Salmonella typhi, Vibrio cholera, and Proteus vulgaris. The recent study concluded that S. marianum with synthesized nanoparticles is a potential plant for pharmacological and antibacterial applications, including anti-infection and anticancer drugs.