Oral administration of KF41399 improved the reduction of CFC activity caused by ACNU.

In the ACNU-treated group, mice were administered 45 mg/kg ACNU IV for 2 consecutive days on day 3 and day 4 (protocol I, Table 1). In the KF41399 pretreated group, mice were treated with 25 mg/kg KF41399 orally twice daily for 10 days from day 0 to day 9. This was followed by the IV administration of 45 mg/kg ACNU for 2 consecutive days on day 3 and day 4 (protocol H, Table 1). Control animals were administered distilled water (protocol A, Table 1). On day 7, MNC was prepared and 10⁴ MNC were seeded in 0.3% of soft agar medium, as described in “Materials and methods.” n = 5 in each group.