TABLE 2.

Summary of the antiviral activity of Viola tricolor peptide-enriched fractions.

Fraction #	CC50 (µg/ml)*	IC50 (µg/ml)*	SI#
1	464.3 ± 31.9	>500	<0.9 ± 0.1
2	>500	>500	nd
3	485.8 ± 123.9	111.1 ± 114.2	8.3 ± 6.7
4	73.8 ± 32.5	21.0 ± 18.3	11.7 ± 15.5
5	103.2 ± 9.5	20.5 ± 28.2	18.6 ± 16.4

*CC50 and IC50 were determined by nonlinear regression from concentration-response curves (Figure 3). Values represent means ± SD of three independent experiments in triplicates. Since 500 μg/ml was the highest concentrations used, no higher half-maximal concentrations could be calculated.

#SI, was calculated by dividing CC50 by IC50. nd: not determined.