Tags

Type your tag names separated by a space and hit enter

Effects of antioxidants on the oxidative susceptibility of low-density lipoprotein.
J Nutr Sci Vitaminol (Tokyo) 1997; 43(4):435-44JN

Abstract

An important event in the pathogenesis of atherosclerosis is believed to be the oxidative modification of low-density lipoprotein (LDL) initiated by a free radical-driven lipid peroxidation process. Vitamin E acts as a lipophilic chain-breaking antioxidant, while water-soluble chain-breaking antioxidants such as vitamin C or uric acid suppress the oxidation of LDL initiated by aqueous radicals. In this study, we established a new method of measuring the lag time of inhibited lipid peroxidation using the lipophilic azo radical initiator V-70:2-2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) and investigated in vitro the susceptibility of LDL to oxidation using this method when lipid- and water-soluble antioxidants were added. When the lipid-soluble antioxidant, vitamin E, was added to LDL, the lag time was extended whereas a higher dose of vitamin E led to a shortened lag time of V-70-induced lipid peroxidation in LDL. These results suggest that vitamin E radicals (tocopheroxyl radicals) act as prooxidants during the autoxidation of LDL. It was also shown that the shortened lag time induced by higher doses of vitamin E was restored when lipid- and water-soluble antioxidants were added simultaneously, which suggests that vitamin E radicals derived from vitamin E are subsequently reduced by vitamin C to regenerate vitamin E. Thus, the interaction between lipid- and water-soluble antioxidants provides an important function in maintaining LDL resistance to oxidation.

Authors+Show Affiliations

Division of Clinical Nutrition, National Institute of Health and Nutrition, Tokyo, Japan.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

9328862

Citation

Hirano, R, et al. "Effects of Antioxidants On the Oxidative Susceptibility of Low-density Lipoprotein." Journal of Nutritional Science and Vitaminology, vol. 43, no. 4, 1997, pp. 435-44.
Hirano R, Kondo K, Iwamoto T, et al. Effects of antioxidants on the oxidative susceptibility of low-density lipoprotein. J Nutr Sci Vitaminol. 1997;43(4):435-44.
Hirano, R., Kondo, K., Iwamoto, T., Igarashi, O., & Itakura, H. (1997). Effects of antioxidants on the oxidative susceptibility of low-density lipoprotein. Journal of Nutritional Science and Vitaminology, 43(4), pp. 435-44.
Hirano R, et al. Effects of Antioxidants On the Oxidative Susceptibility of Low-density Lipoprotein. J Nutr Sci Vitaminol. 1997;43(4):435-44. PubMed PMID: 9328862.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Effects of antioxidants on the oxidative susceptibility of low-density lipoprotein. AU - Hirano,R, AU - Kondo,K, AU - Iwamoto,T, AU - Igarashi,O, AU - Itakura,H, PY - 1997/8/1/pubmed PY - 1997/11/5/medline PY - 1997/8/1/entrez SP - 435 EP - 44 JF - Journal of nutritional science and vitaminology JO - J. Nutr. Sci. Vitaminol. VL - 43 IS - 4 N2 - An important event in the pathogenesis of atherosclerosis is believed to be the oxidative modification of low-density lipoprotein (LDL) initiated by a free radical-driven lipid peroxidation process. Vitamin E acts as a lipophilic chain-breaking antioxidant, while water-soluble chain-breaking antioxidants such as vitamin C or uric acid suppress the oxidation of LDL initiated by aqueous radicals. In this study, we established a new method of measuring the lag time of inhibited lipid peroxidation using the lipophilic azo radical initiator V-70:2-2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) and investigated in vitro the susceptibility of LDL to oxidation using this method when lipid- and water-soluble antioxidants were added. When the lipid-soluble antioxidant, vitamin E, was added to LDL, the lag time was extended whereas a higher dose of vitamin E led to a shortened lag time of V-70-induced lipid peroxidation in LDL. These results suggest that vitamin E radicals (tocopheroxyl radicals) act as prooxidants during the autoxidation of LDL. It was also shown that the shortened lag time induced by higher doses of vitamin E was restored when lipid- and water-soluble antioxidants were added simultaneously, which suggests that vitamin E radicals derived from vitamin E are subsequently reduced by vitamin C to regenerate vitamin E. Thus, the interaction between lipid- and water-soluble antioxidants provides an important function in maintaining LDL resistance to oxidation. SN - 0301-4800 UR - https://www.unboundmedicine.com/medline/citation/9328862/Effects_of_antioxidants_on_the_oxidative_susceptibility_of_low_density_lipoprotein_ L2 - https://medlineplus.gov/antioxidants.html DB - PRIME DP - Unbound Medicine ER -