Table II.
Effects of I3C and silibinin, alone or in combination, on NNK-induced pulmonary lesions in A/J micea
| Group | Compound (μmol/g diet) | No. of mice per group | Hyperplasia per mouse | % reductionb | Adenoma per mouse | % reductionb | Adenoma with cellular pleomorphism per mouseb | % reductionb | Adenocarcinoma per mouseb | % reductionb |
| 1 | None | 12 | 2.6 ± 0.6 | 3.6 ± 1.4 | 2.5 ± 1.0 | 0.6 ± 0.4 | ||||
| 2 | I3C (10) | 10 | 1.8 ± 1.1 | 31 | 3.6 ± 1.2 | – | 0.4 ± 0.5 (P < 0.0001) | 84 | 0.1 ± 0.3 (P = 0.0046) | 83 |
| 3 | Silibinin (7) | 10 | 1.0 ± 0.9 | 62 | 3.5 ± 1.5 | 3 | 0.8 ± 0.9 (P = 0.0005) | 68 | 0.3 ± 0.4 (P = 0.0608) | 50 |
| 4 | I3C (10) + Silibinin (7) | 10 | 1.8 ± 1.1 | 31 | 4.4 ± 1.4 | – | 0.2 ± 0.2 (P < 0.0001) | 92 | 0.03 ± 0.1 (P = 0.0003) | 95 |
| 5 | None | 10 | 0.4 ± 0.5 | 0.03 ± 0.1 | – | – |
a
With the exception of mice in Group 5 (the vehicle control), mice in all other groups received NNK (intraperitoneally, at a dose of 50 mg/Kg, twice a week, for a total of four doses) in 0.1 ml physiological saline solution. I3C, silibinin or I3C plus silibinin were added to the diet beginning from 1 week after the last carcinogen injection until the termination of the study at week 27. Upon killing of the mice, the left lobe of the lung was preserved in 10% buffered formalin and histopathologically analyzed for the presence of lung lesions.
b
Percentage reductions and P values are calculated compared with Group 1.