Biogenic Silver Nanoparticles from Stereospermum kunthianum Cham Stem Bark Extract: Synthesis, Characterization, In Vitro Antimicrobial Study and Cytotoxicity Effects Against Brine Shrimp Artemia

Metal nanoparticles as a category of nanomaterial are receiving interest due to their wide range of applications including in biomedical fields. Among these nanoparticles, silver nanoparticles are the most extensively studied for medical applications because they have been proven to exhibit excellent activity against a wide range of medically significant pathogenic microorganisms, including bacteria, viruses, fungi, and yeasts. In this work, silver nanoparticles were biogenically synthesized using the stem bark extract of Stereospermum kunthianum Cham as capping agent. Physicochemical properties, antioxidant activity, antimicrobial properties and in vitro cytotoxicity of the synthesized AgNPs were studied following standard procedures. UV-Vis studies show broad absorbance peak of the nanoparticles between 430 and 450 nm, SEM image shows that some of the synthesized nanoparticles are near spherical shape with many of the particles appear to have irregular shapes while the material average crystalline size from the XRD analysis was 27.878 mm. The synthesized AgNPs exhibits moderate antioxidant activity with IC50 value of 124.84 μg/mL. Among the microorganism tested, the AgNPs shows more activity against Staphylococcus aureus than Salmonella typhi and Candida albicans. Brine shrimp lethality test of the synthesized AgNPs indicates some level of cytotoxicity with LC50 of 461.850 μg/mL. using biological materials as reducing agents remains best green approach for the synthesis of silver nanoparticles.