IN-VITRO SELECTIVE TOXICITY OF TOXIN T-514 FROM KARWINSKIA-HUMBOLDTIANA (BUCKTHORN) PLANT ON VARIOUS HUMAN TUMOR-CELL LINES

Toxin T-514 is a dimeric anthracenone isolated from the Karwinskia humboldtiana (buckthorn) plant. Its potential anti-neoplastic effect was evaluated in vitro and the results obtained were compared with the effect of other known anti-cancer agents. Normal and malignant continuous cell lines were tested. After a 72-h exposure, neoplastic cells derived from hepatic, pulmonary and colonic tissues were more sensitive to toxin T-514 than normal cells from the corresponding organ. Hepatoma cells and colon adenocarcinoma CT50 values were < 10 mu g/ml. Lung adenocarcinoma, undifferentiated bronchogenic cancer cells and small cell carcinoma CT50 values were < 20 mu g/ml. All benign cell CT50 levels tested were > 113 mu g/ml. This in vitro selective toxicity found with toxin T-514 was also seen with 5-fluorouracil and mitomycin for colon adenocarcinoma and with epidoxorubicin for undifferentiated bronchogenic cancer cells.