Effect on replication level of HRV-4. The RNA replication level of human rhinovirus (HRV-4) was detected by real-time reverse transcription-PCR with SYBR Green dye in HeLa cells 2 days after infection in the presence of 50 μg/mL ellagic acid (EA). HRV RNA expressions were normalized to the constitutive expression of mRNA of the housekeeping gene β2-microglobulin (B2M) and analyzed by the 2–∆∆C T method using StepOne Software v2.1 and DataAssist Software. Each bar represents the mean ± SD of duplicate samples of three independent experiments. ***Significant at P < 0.001, according to a Student’s t-test.