Enhancement of vinblastine-induced cytotoxicity by lysolecithin and phosphatidylinositol.
Vinblastine inhibited the growth of cultured KB cells 3 days after drug treatment by 55% and 67% at 2.7 ng/ml and 3.5 ng/ml of the medium, respectively. Lysolecithin and phosphatidylinositol showed only a marginal inhibitory effect on the growth of KB cells at respective concentrations of 35-125 microgram/ml and 50-150 microgram/ml of the medium. Lysolecithin, however, enhanced the cytotoxicity of vinblastine. Depending upon the concentrations of lysolecithin (35-125 microgram/ml), the growth of KB cells was inhibited by 60-91% and 86-98% at respective vinblastine concentrations of 2.7 ng/ml and 3.5 ng/ml. Enhancement of vinblastine-induced cytotoxicity also occurred similarly for phosphatidylinositol. The mechanism could be explained partly by an elevated amount of intracellular vinblastine. Other possible mechanisms can only be speculated.
D002478:Cells, Cultured; D004357:Drug Synergism; D008244:Lysophosphatidylcholines / Q000494:pharmacology*; D010716:Phosphatidylinositols / Q000494:pharmacology*; D014747:Vinblastine / Q000494:pharmacology*
D008244:Lysophosphatidylcholines; D010716:Phosphatidylinositols; D014747:Vinblastine