[Inhibition of pulmonary metastases in mice by beta-cyclodextrin-benzaldehyde]

The effect of beta-cyclodextrin-benzaldehyde (CDBA) on the pulmonary metastasis in C3H/He mice was examined. When mice were treated daily with CDBA, 3 weeks later the number of lung nodules developed after i.v. inoculation of 1 X 10(6) RCT (+) cells was significantly decreased. The mean numbers of the lung nodules were 69.9 and 73.4 in the water-and cyclodextrin (CD)-treated mice, respectively. However, these were 17.8, 9.8 and 2.9 in 0.5, 5 and 25 mg/mouse per day CDBA-treated mice, respectively. And also, daily treatment of CDBA prolonged the survival time of the tumor bearing mice in both experimental and spontaneous metastasis studies. Two or three weeks after subcutaneous inoculation of RCT (+) cells (1 X 10(6) cells) to the foot pad, left hindlimbs were amputated and then mice were daily treated or untreated with CDBA. Five weeks after tumor inoculation, the number of lung nodules was counted. Twenty eight point six and 100% of untreated mice had lung metastases when amputation was carried out 2 (earlier operation group) and 3 (latero peration group) weeks after tumor inoculation. However, in CDBA-treated mice, these values were noticeably decreased, that is, 6.7% and 60% in earlier and later operation groups, respectively. Furthermore, in the later operation group, mean number of the lung nodules in CDBA-treated mice was only 2.7 while this was 12.9 in untreated mice. These data suggest that CDBA improve the survival time of tumor bearing mice through the inhibition of the lung metastasis.