Abstract
We examined the effects of polyethyleneglycol (PEG)-coated liposome containing adriamycin (PEG-LADR)on the antitumor activity and toxic side effect of adriamycin (ADR), using Ehrlich ascites carcinoma bearing CDF1, male mice. PEG-LADR significantly enhanced the antitumor activity of ADR against the solid tumor. This increment of antitumor activity induced by PEG-coated liposomalization supported by the elevation of ADR concentration in the tumor. Next, we examined two biochemical parameters, lipid peroxide (LPO) level and glutathione peroxidase (GSHpx) activity, as indices of ADR induced side effects. There were the increase of LPO level and the decrease of GSHpx activity in the heart of mice after ADR solution administration. ADR concentration in the heart on the 24th hour after PEG-LADR administration showed higher than that after ADR solution treatment. However, PEG-LADR administration were not changed LPO level and GSHpx activity in the heart, compared to normal level. In the liver and the pancreas, same results were shown. Furthermore, regarding the lethal effect of ADR, the acute toxicity after PEG-LADR treatment significantly reduced, compared to that after ADR solution treatment. Therefore, these results suggested that PEG-LADR can significantly increase the antitumor activity of ADR solution with decreasing its side effects, and the side effects of liposomal ADR should not evaluated by ADR concentration in each tissues.
