Effect of Web 2170 BS, Platelet Activating Factor Receptor Inhibitor, in the Guinea PIG Model of Middle Ear Inflammation

Abstract

Platelet activating factor (PAF), a potent inflammatory mediator, is a biologically active phospholipid. Recent studies have shown that PAF may play an important role in the pathogenesis of otitis media (OM). WEB 2170 BS has been shown to be a PAF antagonist both in vitro and in vivo. In this study, the anti-inflammatory effects of WEB 2170 BS were investigated in a guinea pig model of OM induced by middle ear (ME) inoculation of killed Staphylococcus aureus. The outcome of treatment was determined by measurement of myeloperoxidase activity in the samples of ME mucosa, evaluation of temporal bone histopathology, and the presence of ME fluid. The myeloperoxidase activity in the WEB 2170 BS-treated group was found to be significantly lower than that in the control group. Histopathology of the temporal bones indicated decreased inflammation in the treated group as compared to the controls. In addition, ME fluid was absent in 16 of the 20 ears of the 10 treated animals. These results demonstrate that WEB 2170 BS can produce significant anti-inflammatory effects in this model of OM.