Cell viability of BEAS-2B cells after exposure to AgNPs. Cell viability of BEAS-2B cells after 24 h exposure to AgNPs (5–50 μg/mL) was assessed using Alamar Blue assay (A) and LDH assay (B). Results are expressed as % mitochondrial activity for the Alamar Blue assay and % membrane integrity for the LDH assay. Results are presented as mean ± standard deviation of 3 independent experiments. Significant results as compared to the control are marked with asterisks (* for P-value < 0.05, ** for P-value < 0.01, *** for P-value < 0.001).