A549 lung cell line activity of biosynthesized silver nanoparticles using Albizia adianthifolia leaf

Stable AgNPs were formed in vitro by reacting AgNO3 (aq) solution with the aqueous plant leaf extract. UV–vis revealed the surface plasmon resonance λmax at 448 nm and the absorbance steadily increased in intensity as a function of reaction time. Transmission electron microscope (TEM) and XRD studies were used to characterize the AgNPs; the size was 4–35 nm. Dynamic light scattering (DLS) was used as supporting evidence to determine hydrodynamic size and zeta potential recorded as 80.27 nm and −24.7 mV, respectively. FT-IR spectra suggest that AgNPs are capped with protein molecules and other water soluble phytocompounds such as saponins and glycosides which also behave as stabilizing agents; TEM images indicate a visible layer surrounding the AgNPs. Prominent absorption bands at 3380 and 1642 cm−1 are assigned to alcohol and carbonyl groups, respectively. 1H NMR of the neat aqueous plant extract indicates presence of a complex mixture of compounds; however the chemical shift at δ 6.0–8.0 and 1.0–4.0 ppm indicates the presence of few aromatic but abundant aliphatic compounds, respectively.Toxicity of AgNPs on lung cancer cells (A549) and normal healthy peripheral lymphocytes (PLs) at 10 μg/ml and 50 μg/ml was assessed using the MTT, ATP and lactate dehydrogenase assays. Viability data for A549 cells showed a 21% (10 μg/ml) and 73% (50 μg/ml) cell viability after 6 h exposure to AgNPs compared to 117% (10 μg/ml) and 109% (50 μg/ml) cell viability of normal peripheral lymphocytes. Lactate dehydrogenase was only significantly altered at 50 μg/ml AgNPs treated cells from 2.43 ± 0.04 units to 0.77 ± 0.04 units.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► This is a green synthesis of AgNPs from leaf extract of Albizia adianthfolia. ► Characterization of AgNPs is by instrumental and physicochemical methods. ► Possible organic components of the biomass and capping agents are presented. ► AgNPs are cytotoxic to lung cancer cells (A549). ► AgNPs are non-cytotoxic to healthy human peripheral lymphocytes (HPLs).