摘要：Many artificial or natural occurring compounds are used as food additives. Although they are very useful in food distribution, the addition of some of them to food is strictly regulated by the law because of their toxicities or mutagenicities. We have investigated the effect of xenobiotics on rabbit platelet functions by means of thromboxane B2 (TXB2) synthesis which was determined by the EIA methods. The present study has been carried out to investigate the effect of five antioxidants ; butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), dl-α-tocopherol (VE), l-ascorbyl palmitate (AP), and propyl gallate (PG) ; used as food additives on rabbit platelet functions both in vitro and ex vivo. Among five antioxidants used, BHT, BHA, AP and PG inhibited A-23187-induced TXB2 synthesis at the concentration of 10-5M when added simultaneously in vitro. On the other hand, all compounds revealed significant inhibitory effects against thrombin-induced TXB2 synthesis at 10-7M and over. Pretreatment of platelet with these compounds also inhibited both agonist-induced TXB2 syntheses, and this inhibitory effect was reduced partly by removal of BHA and PG when platelet was stimulated by A-23187, but no reduction was observed when platelet was stimulated by thrombin. Both agonist-induced activations of platelet from rabbit fed ADI levels of each compound with diet for 5 d were inhibited significantly. These results reveal that the ADI levels of antioxidants used as food additives inhibit the agonist-induced TXB2 synthesis in rabbit platelet.
