摘要：Coloring is added to many foods and beverages to compensate for the loss of color during processing and to enhance their visual appeal. We have been studying the effect of food additives around the ADI level on cellular functions using washed rabbit platelets. The present study was carried out to investigate the effect of natural red colors on rabbit platelet functions both in vitro and ex vivo. Among the 7 natural red colors used (red cabbage, elderberry, purple corn, lac, cochineal, monascus and beet red colors), red cabbage, elderberry and purple corn had an inhibitory effect on A-23187-induced thromboxane B2 (TXB2) synthesis. On the other hand, all colors affected thrombin-induced TXB2 syntheses at concentrations up to 0.2% : red cabbage stimulated, cochineal stimulated or inhibited depending on its concentration, and others inhibited. In the pretreatment experiment, monascus, beet red and cochineal inhibited A-23187-induced TXB2 synthesis, and the effects of the former two colors were irreversible. Thrombin-induced TXB2 syntheses were inhibited by pretreatment with all colors except red cabbage which had a stimulatory effect. These effects were irreversible except for purple corn. Thrombin-induced TXB2 synthesis in the platelet from rabbits, after administering drinking water to which the recommended highest level of each color was added for 5 d, were affected by 3 colors. Namely, elderberry and beet red inhibited and purple corn stimulated. These results indicate that the amount of these compounds added to foods should be reduced to the minimum necessary to lower the risk of their potential hazard to humans.
关键词：food additives;natural red color;rabbit platelet;activation;inhibition;thrombin
