Effect of Long-Term Administration of Narcissus Alkaloid on Rauscher Leukemia and Combinations with Standard Drugs 1

Summary

Long-term treatment with narcissus alkaloid (pseudolycorine or the residual alkaloid) at well tolerated doses was remarkably effective against established Rauscher leukemic mice, in comparison with standard antileukemic drugs. Combination of narcissus alkaloid with cyclophosphamide or 6-MP was more effective than the single administration of either drug, while combination with vincristine or interferon inducers (poly I:C or tilorone HCl) did not increase the effect. Narcissus alkaloid did not impair humoral antibody production in the leukemic mice, while the standard drugs were immunosuppressive during long-term administration. Also, narcissus alkaloid did not suppress interferon induction (by poly I:C) in leukemic mice.

We thank Dr. M. A. Chirigos, NIH, for supplying Rauscher virus, antiviral testing by XC cell assay, and helpful advice; and Dr. P. A. Tavormina, Mead Johnson Res. Center, for supplying cyclophosphamide (Cytoxan).