Ag nanoparticles synthesized using Lavandula angustifolia and their cytotoxic evaluation in yeast

Abstract

Since silver nanoparticles (AgNPs) are currently found in many commercial products, knowledge of their toxicity in yeast cells is essential. Saccharomyces cerevisiae and Kluyveromyces marxianus are very similar to those of higher organisms such as mammals. Therefore, the cytotoxicity information obtained from these organisms can be related in a first approximation to human beings. In the present study, the Lavandula angustifolia plant extract was used as a reducing-stabilizing agent in the synthesis of silver nanoparticles. AgNPs cytotoxicity was evaluated in the yeast strains Kluyveromyces marxianus OFF1 and SLP1, and Saccharomyces cerevisiae MC4 and W303 by growth assay and colorimetric assay (MTT). The AgNPs were characterized by different techniques such as ultraviolet-visible spectroscopy (UV-Vis), infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The DPPH test showed an 80% antioxidant potential in the extract of the Lavandula angustifolia plant and showed a decrease in free radicals attributed to the reduction reaction of Ag+ to AgNPs. SEM and TEM showed AgNPs obtained with an average size of 18 nm and two types of morphologies, spherical and triangular. XRD patterns showed Ag solids with the fcc crystal structure. FTIR spectroscopies in conjunction with NMR confirmed that glycosylated flavonoids were responsible for the stabilization and reduction of NPs. A significant result from this study is that AgNPs did not show cytotoxicity on cell viability and growth inhibition on Kluyveromyces marxianus OFF1 and SLP1 strains, and Saccharomyces cerevisiae MC4 and W303. However, it was verified that those of the genus Kluyveromyces marxianus presented greater resistance to growth and cell viability.