Figure 4. Effect of curcumin on liposomes and viruses with different sizes.

(A) Three different diameters of SRB-Liposome i.e. 300 nm, 220 nm, 120 nm were incubated with curcumin (60 µM), DMSO (the solvent control), or 15 mM n-octylglucoside (n-OG), a detergent serving as positive control, at room temperature for one hour. The leakage of SRB fluorescence was detected by SpectraMax M2e Microplate Reader (Molecular Devices, Inc., California, United States) at excitation wavelength of 490 nm. (B) Effects of curcumin on plaque formation of enveloped viruses with different sizes. 2,000 pfu of influenza virus (strain PR8) and two DNA viruses, i.e. pseudorabies virus (PRV) and vaccinia viruses (VAC) were pre-treated with 30 µM of curcumin for one hour. The plaque formation ability was measured by standard plaque assay and plotted as a percentage of the untreated controls. Dash lines indicate reduction of plaque formation by 50% relative to the control group. Data are presented as mean values ± standard deviation (SD) from three independent experiments.