The "double-faced" effect of VC-12 on free-radical-induced haemolysis of human erythrocytes: antioxidant and prooxidant.
Vitamin C is a popular antioxidant; however, its water solubility limits its function in the lipid environment. As a result, the antioxidative properties of its lipophilic derivatives have aroused research attention, especially L-ascorbyl-6-laurate (VC-12). We have investigated the effect of a high concentration of VC-12 on 2,2'-azobis(2-amidinopropane hydrochloride) (AAPH)-induced haemolysis of human erythrocytes. The findings indicated that VC-12 was capable of protecting erythrocytes against AAPH-induced haemolysis when its concentration was below 60 microM. With an increase in the concentration of VC-12 and a decrease in the concentration of AAPH, VC-12 promoted haemolysis remarkably, the mechanism of which has been proposed as VC-12-mediated peroxidation. When the concentration of VC-12 was increased to above 150 microM, VC-12 promoted haemolysis by its function as a surfactant, to unbalance the osmotic pressure within and outside erythrocytes. High concentrations of VC-12 may have generated radicals via autooxidation, resulting in eventual haemolysis. Therefore, the double-faced effect of VC-12 on haemolysis of human erythrocytes was due to its concentration. This information may be useful for the safe use of lipophilic vitamin C.
Li
Guo-Xiang
GX
Department of Organic Chemistry, College of Chemistry, Jilin University, Changchun 130021, China.
Tang
You-Zhi
YZ
Liu
Zai-Qun
ZQ
D000578:Amidines; D000975:Antioxidants / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004912:Erythrocytes / Q000187:drug effects; D005609:Free Radicals; D006461:Hemolysis / Q000187:drug effects*; D006801:Humans; D015227:Lipid Peroxidation / Q000187:drug effects*; D009997:Osmotic Pressure / Q000187:drug effects; D016877:Oxidants / Q000494:pharmacology*; D010084:Oxidation-Reduction / Q000187:drug effects
D000578:Amidines; D000975:Antioxidants; D005609:Free Radicals; D016877:Oxidants; C006641:ascorbyl monolaurate; C046728:2,2'-azobis(2-amidinopropane); D001205:Ascorbic Acid