Table 2.

Cytotoxicity and antiviral activity of ellagic acid and antiviral agent ribavirin toward human rhinovirus-4 in HeLa cells using sulforhodamine B bioassay

Compound		HRV-2		HRV-3		HRV-4
	CC 50 (μg/mL)	IC 50 (μg/mL) (±SD)	TI a	IC 50 (μg/mL) (±SD)	TI a	IC 50 (μg/mL) (±SD)	TI a
Natural EAb	>100	38 ± 3.2b	>2.6	31 ± 5.2b	>3.2	29 ± 2.5b	>3.4
Pure EA	>100	41 ± 1.1b	>2.4	30 ± 2.4b	>3.3	29 ± 1.7b	>3.4
Ribavirin	>100	70 ± 4.9a	>1.4	71 ± 0.5a	>1.4	63 ± 5.6a	>1.6

Means within a column followed by the same letter are not significantly different (P = 0.05, Bonferroni method).

^aTherapeutic index = CC₅₀/IC₅₀.

^bEllagic acid.