Table 1 In vitro growth inhibitory concentrations at 50% (IC ₅₀ ) in human cancer cells after three days of culture in the presence of the drug of interest

Cardenolides

Ouabain*

37 ± 2

78 ± 1

34 ± 3

80 ± 3

100 ± 17

83 ± 13

63 ± 10

84 ± 8

70 ± 8

Ouabagenin*

866 ± 25

5,281 ± 250

1,902 ± 167

3,600 ± 36

4,011 ± 202

2,563 ± 183

2,708 ± 62

3,482 ± 19

3,052 ± 479

Digoxin*

60 ± 7

227 ± 42

51 ± 6

274 ± 17

363 ± 35

220 ± 26

215 ± 71

208 ± 20

202 ± 37

Digoxigenin*

395 ± 34

3,188 ± 129

794 ± 22

1,171 ± 99

5,321 ± 170

4,005 ± 116

3,880 ± 87

4,458 ± 83

2,902 ± 658

Digitoxin**

11

61

15

32

187

59

37

198

75 ± 26

Digitoxigenin**

92

369

79

166

2,134

2,495

298

230

733 ± 349

Gitoxin**

68

351

79

174

828

679

361

352

362 ± 96

Gitoxigenin**

1,715

4,477

653

3,589

5,193

> 10,000

3,964

4,403

> 4,249

Uzarigenin-rhamnoside**

45

247

38

38

469

222

77

41

147 ± 55

Uzarigenin**

3,169

7,918

2,252

5,138

> 10,000

> 10,000

6,281

6,439

> 6,025

Bufadienolides

Gamabufotalin-rhamnoside*

3 ± 1

6 ± 2

4 ± 1

7 ± 1

17 ± 5

18 ± 7

6 ± 1

8 ± 1

9 ± 2

Gamabufotalin*

7 ± 1

34 ± 1

14 ± 3

31 ± 8

40 ± 7

22 ± 1

22 ± 4

37 ± 3

26 ± 4

Hellebrin*

6 ± 1

41 ± 2

7 ± 1

30 ± 1

58 ± 12

40 ± 5

11 ± 1

27 ± 4

28 ± 7

Hellebrigenin*

3 ± 1

9 ± 1

6 ± 1

9 ± 1

42 ± 2

28 ± 9

18 ± 1

9 ± 1

16 ± 5