Biological properties of Vincaleukoblastine, an alkaloid in Vinca rosea Linn, with reference to its antitumor action.

Abstract

Summary Some biological effects of a new alkaloid, Vincaleukoblastine (VLB), are described. In mice bearing the transplantable leukemias L1210, P1534, and AKr or Ehrlich ascites tumor, treatment with VLB effectively prolonged survival. The effectiveness of treatment depended on the amount and spacing of dosage and the time of the institution of treatment after transplantation. A single injection of VLB was highly active, but hourly doses were probably the most effective. VLB was also active when incubated with tumor cells. Transplanted or spontaneous mammary tumors in C3H mice also showed a reduced growth during treatment with VLB. Mice “cured” of AKr or P1534 transplanted leukemia by treatment with VLB were subsequently resistant to repeated challenges by the tumor. AK mice, so treated, have to date not developed spontaneous leukemia. Fischer rats bearing transplanted IRC 741 leukemia also responded to VLB treatment. Circulating tumor cells were particularly affected. VLB did not inhibit regeneration of the liver of the partially hepatectomized rat. Bone marrow depression was striking, although megakaryocytes were little affected. Intestinal lesions were absent. The mouse tolerated greater doses of VLB than did the rat or the guinea pig.