Sialic acid is an essential moiety of mucin as a hydroxyl radical scavenger

In this work, we examined the antioxidant role of mucin, a typical sialic acid containing high-molecular weight glycoprotein. The function of mucin as a hydroxyl radical (OH) scavenger was characterized using bovine submaxillary gland mucin (BSM). Non-treated BSM effectively protected DNA from the attack of OH; however, desialylated BSM lost this potential. Moreover, we estimated the scavenging effects of BSM against OH generated by UV irradiation of hydrogen peroxide using ESR analysis. Our results indicate that BSM has OH scavenging ability the and sialic acid in mucin is an essential moiety to scavenge OH.