Antipoliovirus Activity of the Organic Extract of Eupatorium buniifolium: Isolation of Euparin as an Active Compound

Table 1

Cytotoxicity and antiviral activity of extracts, fractions, and euparin against PV-1, PV-2, and PV-3.

	CC50 (µg/mL)	PV-1			PV-2			PV-3
		EC50; (𝜇g/mL)	EC90; (𝜇g/mL)	SI	EC50; (𝜇g/mL)	EC90; (𝜇g/mL)	SI	EC50; (𝜇g/mL)	EC90; (𝜇g/mL)	SI
E. buniifolium OE	114.8±1.8	23.3±3.3	47.2±2.8	5.5	25.0±1.8	41.5±3.4	4.6	21.1±2.5	38.8±5.7	4.8
E. buniifolium AE	>2000	Inactive	—	—	Inactive	—	—	Inactive	—	—
Fraction F1	n.d.	Inactive	—	—	n.d.	—	—	n.d.	—	—
Fraction F2	254.2±1.2	13.3±2.6	32.6±1.4	19	n.d.	—	—	n.d.	—	—
Fraction F3	140.8±2.7	27.8±1.1	43.3 ± 2.4	5.1	n.d.	—	—	n.d.	—	—
Fraction F4	205.1±3.4	19.4±1.6	27.2±0.2	10.6	n.d.	—	—	n.d.	—	—
Fraction F5	n.d.	Inactive	—	—	n.d.	—	—	n.d.	—	—
Euparin	128.2±2.2	0.47±0.05	1.01±0.01	284.9	0.12±0.01	0.52±0.01	1068	0.15±0.01	0.36±0.07	854.7

The maximal concentration tested for antiviral activity was 100 𝜇g/mL; the extract or fractions were considered inactive if they were unable to inhibit viral replication at this concentration.
n.d.: not determined.
CC₅₀: concentration that reduces cell viability by 50% with respect to cell control; EC₅₀: concentration that reduces the number of viral plaques by 50% with respect to the viral control; EC₉₀: concentration that reduces the number of viral plaques by 90% with respect to the viral control; SI = CC₅₀/EC₅₀.