title: Alpha-lipoic acid reduction by mammalian cells to the dithiol form, and release into the culture medium.
abstract: Lipoic acid has been reported recently to be an effective antioxidant in biological systems. It may act in vivo through reduction to its dithiol form, dihydrolipoic acid. Using a dual Hg/Au electrode, and HPLC with electrochemical detection, a method was developed which allowed simultaneous measurement of lipoic acid and dihydrolipoic acid, at nanomolar levels. (RS)-alpha-Lipoic acid was added to human cells in tissue culture (Jurkat T-lymphocytes and primary neonatal diploid fibroblasts). Lipoic acid was converted rapidly by the cells to dihydrolipoic acid, which accumulated in the cell pellet. Monitored over a 2-hr interval, dihydrolipoic acid was released, and several-fold more dihydrolipoic acid could be found in the medium than in the pellet.
authors.affiliation: University of California, Berkeley 94720.
authors.forename: G J
authors.initials: GJ
authors.lastname: Handelman
authors.forename: D
authors.initials: D
authors.lastname: Han
authors.forename: H
authors.initials: H
authors.lastname: Tritschler
authors.forename: L
authors.initials: L
authors.lastname: Packer
mesh_terms: D002851:Chromatography, High Pressure Liquid; D003470:Culture Media / Q000737:chemistry; D004566:Electrodes; D006801:Humans; D010084:Oxidation-Reduction; D013438:Sulfhydryl Compounds / Q000378:metabolism*; D008063:Thioctic Acid / Q000031:analogs & derivatives* / Q000378:metabolism*; D014407:Tumor Cells, Cultured
chemical_list: D003470:Culture Media; D013438:Sulfhydryl Compounds; D008063:Thioctic Acid; C015144:dihydrolipoic acid