Protective effect of propionyl-L-carnitine against PAF-induced rat paw oedema

Recent reports from our laboratory gave evidence showing that propionyl-L-carnitine (PLC), unlike L-carnitine (LC) and acetyl-L-carnitine (ALC), has anti-inflammatory activity in some models of vascular inflammation in rodents. The present paper shows that PLC (50 to 200 mg kg-1 i.p.) inhibits rat paw oedema induced by platelet activating factor (PAF), while LC and ALC, as well as indomethacin and phenylbutazone, are ineffective. The extent of the maximal inhibition produced by PLC at 200 mg kg-1 was comparable to that of betamethasone 0.05 mg kg-1 or sodium salicylate 100 mg kg-1. PLC inhibited also the early phase (1-2 h) of carrageenin-induced rat paw oedema, which is partly dependent on PAF release, but it was ineffective in the eicosanoid-dependent late phase (3-4 h) of the carrageenin oedema. We suggest that such anti-inflammatory activity of PLC may be due to various mechanisms converging on a stabilizing action upon biomembranes.