Differential inhibitory effects of vitamin E and other antioxidants on prostaglandin synthetase,platelet aggregation and lipoxidase

Prostaglandin biosynthesis from eicosa-8,11,14-trienoic acid in microsomes from the bovine vesicular gland is inhibited by the antioxidants α-naphthol, guaiacol, NDGA and propyl gallate. Prostaglandin biosynthesis in this system is not inhibited by the antioxidants BHT, DL-α-tocopherol and Trolox C. Arachidonic acid induced platelet aggregation is inhibited specifically by α-naphthol, guaiacol, NDGA and propyl gallate. Both arachidonic acid induced platelet aggregation and ADP induced platelet aggregation are inhibited non-specifically by the antioxidants BHT, DL-α-tocopherol and Trolox C. All antioxidants tested in this study inhibit soybean lipoxidase. Thus α-naphthol, NDGA and propyl gallate are non-specific inhibitors of both prostaglandin synthetase and soybean lipoxidase while BHT, DL-α-tocopherol and Trolox C are specific inhibitors of soybean lipoxidase alone.