Platelet-activating factor (PAF) is a potent
phospholipid-derived messenger molecule involved in a number of pathological conditions, including mediation of inflammatory cascades associated with wound healing. We investigated prophylactic and
therapeutic effects of a specific PAF antagonist,
BN52020, on the course of experimentally induced oral mucosal
ulcer healing. The prophylactic
BN52020 administration produced an accelerated
ulcer healing that was characterized by a marked induction in COX-2
enzyme protein expression and the substantial decline in apoptosis,
TNF-alpha, and NOS-2 activity. A delay in
ulcer healing, however, occurred with the therapeutic
BN52020 administration, and this effect of the agent was reflected in a decreased expression of COX-2
protein, higher rate of apoptosis, and the elevated level of
TNF-alpha and NOS-2. Our findings implicate PAF requirement in orderly progression of the events involved in oral tissue repair, and suggest that the interference with its actions during healing process results in the suppression of COX-2-derived anti-inflammatory
prostaglandins that delay the mucosal repair.