Figure 3.

Anti-noroviral activity of Lindera obtusiloba leaf extract (LOLE) single compounds against murine norovirus (MNV-1). MNV-1 virus particles were preincubated with 15, 30 and, 60 mM LOLE solutions for 1 h at 25 °C before infection of RAW 264.7 cells. (A) The effect on plaque formation (%) of LOLE compounds was evaluated by plaque reduction assays. MNV-1 infectivity was calculated as a percentage of plaque formation using a dimethyl sulfoxide (DMSO)-treated control as a reference. (B) Quantification of viral mRNA of MNV-1 in infected RAW 264.7 cells. Gene expression is shown as fold-change relative to the expression in control (glyceraldehyde 3-phosphate dehydrogenase; GAPDH). The white bars represent the control groups, whereas the gray bars represent the intervention groups. Results are expressed as the percentage of neutralized virus compared to control (mean ± SEM; n = 3). * p < 0.05, ** p < 0.01 vs. DMSO.