Exploration of reducing and stabilizing phytoconstituents in Arisaema dracontium extract for the effective synthesis of Silver nanoparticles and evaluation of their antibacterial and toxicological proprties

Medicinal plants have been widely used for their antimicrobial properties against various microorganisms. Arisaema dracontium a familiar medicinal plant, was analyzed and silver nanoparticles (AgNPs) were synthesized using extracts of different parts of its shoot including leaves and stem. Further, the antimicrobial activity of different solvent extracts such as ethyl acetate, n -hexane, ethanol, methanol, and chloroform extracts were analyzed. AgNPs were prepared using aqueous silver nitrate solution and assessed their antibacterial activity against multidrug-resistant (MDR) and Non-multidrug-resistant bacteria. The characterization of AgNPs was done by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), UV -visible spectroscopy, Fourier Transform Infrared (FTI), and X-ray Diffraction approaches. The leaf extract contained Tannins, Flavonoids, Terpenoids, and Steroids while Alkaloids, Saponins, and Glycosides were undetected. The stem extract contained Alkaloids, Tannins, Flavonoids, Saponins, Steroids, and Glycosides while Terpenoids were not observed. The AgNPs synthesized from stem and leaf extracts in the current study had spherical shapes and ranged in size from 1 to 50 nm and 20 -500 nm respectively as were visible in TEM. The leaf extract -prepared AgNPs showed significantly higher activities i.e., 27.75 mm +/- 0.86 against the MDR strains as compared to the stem -derived nanoparticles i.e., 24.33 +/- 0.33 by comparing the zones of inhibitions which can be attributed to the differences in their phytochemical constituents. The acute toxicity assay confirmed that no mortality was noticed when the dosage was 100 mg per kg which confirms that the confirms that the AgNPs are not toxic when used in low quantities. It is concluded that leaf extract from A. dracontium could be used against pathogenic bacteria offering economic and health benefits compared to the chemical substances.