NEUTRALIZING EFFECT OF ZINC-OXIDE ON DEHYDROABIETIC ACID-INDUCED TOXICITY ON HUMAN POLYMORPHONUCLEAR LEUKOCYTES

The cytotoxic effect of dehydroabietic acid (DHAA), a resin acid found in rosin, was studied on human polymorphonuclear leukocytes (PMN) using leakage of Cr-51 from prelabeled cells, supravital staining, and transmission electron microscopy. DHAA caused a strong dose-related release of Cr-51, a high uptake of trypan blue, and total cell necrosis as seen in transmission electron microscopy. Albumin slightly reduced the toxic effects, whereas the addition of zinc in various forms strongly inhibited these toxic effects of DHAA in the concentration range 10-500-mu-g/mL. In the presence of albumin, zinc oxide as a suspension inhibited the damage of the cell membranes more than a filtrate of zinc oxide, indicating a subsequent slow release of zinc from the zinc oxide.