Table 3.

In vitro cytotoxicity of isolated compounds from the combined fractions CSPE4/CSPE5.

	WI38 IC50 (µg/ml)	J774 IC50 (µg/ml)	IS (IC50  WI38/IC50 J774)
Compound 1	19.24 ± 0.55 (4.51 µM)	12.60 ± 0.23 (2.96 µM)	1.5∗∗∗
Mixture of compounds 3a/3b	16.50 ± 0.24 (3.6 µM)	1.79 ± 0.03 (0.39 µM)	9.2∗∗∗
Camptothecin	0.175 ± 0.08 (0.05 µM)	0.011 ± 0.004 (0.0031 µM)	15∗∗∗

Compound 1: lupeol; mixture of compounds 3a/3b: 25-hydroperoxycycloart-23-en-3β-ol and 24-hydroperoxycycloart-25-en-3β-ol; camptothecin: positive control; results are expressed as mean ± standard error of the mean (SEM) of six determinations and activity differences between cell lines are statistically defined for each compound with the Mann–Whitney or Wilcoxon signed-rank tests for comparison to the highest tested concentration (p < 0.005^∗∗∗).