Novel synthesis of nanosilver particles using plant active principle aloin and evaluation of their cytotoxic effect against Staphylococcus aureus

Objective: To develop a reliable, eco-friendly and easy process for the synthesis of silver\udnanoparticles using aloin, the active principle of medicinal plant ‘Aloe vera ’ and to evaluate\udantimicrobial activity against Staphylococcus aureus (S. aureus), a causative organism of most of\udthe diseases in livestock and to standardize the level of safety of synthesized silver nanoparticles.\udMethods: Characterization using UV-vis spectrophotometry, DLS technique, FT-IR and SEM.\udTube dilution method was carried out to evaluate the MIC of the compound against S. aureus. MTT\udassay was performed to evaluate the level of safety of nanoparticles.\udResults: UV-vis absorption spectrum showed a maximum absorption around 200 nm for aloin\udmediated silver nanoparticles (ANS). The size of the particles as measured by DLS technique was\ud67.8 nm. The results of FT-IR analysis indicated the involvement of hydroxyl, carboxyl, amine\udand nitrile groups in the synthesis and stabilization of aloin mediated silver nanoparticles. SEM\udimages showed that ANS with cubical, rectangular, triangular and spherical morphology and\udmeasured sizes of the agglomerated nanoparticles are in a range of 287.5 to 293.2 nm, however the\udaverage size of an individual particle is estimated to be approximately 70 nm. The compound (ANS)\udshowed a MIC of 21.8 ng/mL against S. aureus and showed an in vitro spleenocyte viability of more\udthan 80% at the highest concentration of 87.5 mg/L per well.\udConclusions: Aloin consists of functional groups which reduced Ag+ ions to Ago ions and helped\udin synthesis of silver nanoparticles. The synthesis process has further enhanced the antimicrobial\udactivity of nanosilver. The compound is also proved to be safe at the level many times higher than\udthe MIC