Antiviral and Anti-Inflammatory Activities of Pochonin D, a Heat Shock Protein 90 Inhibitor, against Rhinovirus Infection

Song, Jae-Hyoung; Shim, Aeri; Kim, Yeon-Jeong; Ahn, Jae-Hee; Kwon, Bo-Eun; Pham, Thuy Trang; Lee, Jongkook; Chang, Sun-Young; Ko, Hyun-Jeong

Antiviral activity was assessed by the SRB method using cytopathic effect (CPE) reduction as reported previously (Song et al., 2014) . Briefly, one day prior to infection, Hela cells (2×10 4 cells/well) were seeded onto a 96-well culture plate (BD biosciences, San Jose, CA, USA). On the next day, medium was replaced with medium containing 30 mM of MgCl2, 1% FBS, diluted virus suspension containing a 50% cell culture infective dose (CCID50) of the virus, and an appropriate concentration of the test compounds. The culture plates were incubated at 32°C in 5% CO2 for 2 days until the appropriate CPE was achieved. After incubation in ice-cold 70% acetone for 30 min, cells were stained with 0.4% (w/v) SRB in 1% acetic acid solution. Cell morphology was observed using an Axiovert microscope (Axiovert 10; Carl Zeiss, Oberkochen, Germany) to examine the effect of the compounds on HRV-induced CPE. Bound SRB was then solubilized with 10 mM unbuffered Tris-based solution, and absorbance was read at 562 nm using a VERSAmax microplate reader (Molecular Devices, Palo Alto, CA, USA) with reference absorbance measured at 620 nm. The percentage of cell viability was calculated for comparison based on the measured absorbance. In addition, the cell morphology was observed under a microscope at 32×10 magnification (St Ernst-Leitz, Wetzlar, Germany), and images were recorded.