A platelet-activating factor (PAF) receptor antagonist which influences the primary physiological responses of rodents to PAF

Abstract

The effect of borage oil supplementation on collagen-induced platelet aggregation and pro-aggregatory thromboxane A2 (TxA2), prostaglandin E2 (PGE2) and anti-aggregatory prostaglandin E1 (PGE1) formation was evaluated. Male volunteers consumed, on average, 5.23 g of gamma-linolenic acid (GLA, 18:3n-6) (as borage oil) daily for 42 days followed by a 42 day wash-out period. The increased platelet aggregation at day 22 and 43 was not accompanied by a statistically significant rise in TxA2, PGE1, and PGE2 formation or in their ratios despite the significantly increased dihomo-gamma-linolenic acid (DGLA, 20:3n-6) arachidonic acid (AA, 20:4n-6) ratio in the platelet phospholipids. These observations suggest that the enhanced platelet aggregation may be mediated by GLA, some other component of borage oil or by a non-eicosanoid mechanism. Another experiment suggested high density lipoprotein (HDL) and low density lipoprotein (LDL) from borage oil consumers did not affect collagen-stimulated autologous platelet aggregation and TxA2 formation.