Inhibiting effect of levamisole on superoxide production from rat mast cells.

The aim of the present study was to test whether levamisole acts as a superoxide scavenger. The drug was incubated at four different concentrations (range 1, 5, 10, 20 micrograms/ml) with purified rat mast cells which were then induced to generate superoxide ions, by challenge with compound 48/80 (1 microgram/ml). Ten minutes preincubation with the drug completely abolished superoxide ions production. Addition of levamisole to the cell suspension simultaneously with the releaser caused full inhibition of O2(-) generation at the lowest dose, while higher doses failed to suppress 48/80 induced O2(-) generation. In a cell-free superoxide-generating system, like xanthine-xanthine oxidase, levamisole did not act as a superoxide scavenger at any of the doses tested.