Alpha-lipoic acid as a biological antioxidant

Antioxidants and polyunsaturated fatty acids in multiple sclerosis

“…Both compounds are capable of scavenging superoxide radicals (Suzuki et al, 1991) and are integrated in the antioxidant network (Figure 3). DHLA is capable of reducing GSSG to GSH and can regenerate ascorbate, either by direct reaction with dehydroascorbate or through reduction of GSSG to GSH, which is also a reducing agent for ascorbate (Packer et al, 1995).…”

Exercise and oxidative stress: Sources of free radicals and their impact on antioxidant systems

“…Several biological compounds such as ~-lipoic acid, uric acid, and ubiquinone also demonstrate antioxidant functions, but they are not considered vitamins as most mammals can synthesize these compounds and their functions are not exclusively restricted to antioxidants (4,54).…”

“…Recently, a great deal of attention has been given to the antioxidant potential of its reduced form, dihydrolipoic acid (DHLA). Both (x-lipoic acid and DHLA have exhibited specific scavenging capacities for a variety of free radicals, such as 02, "OH, 102, peroxyl radical, and hypochlorous radical (54). They are chelators of transition metal ions, and therefore prevent damaging free radical chain reaction~;.…”

“…DHLA is capable of regenerating other antioxidants such as vitamin E and vitamin C from their radical forms either directly or indirectly via the GSH-GSSG redox cycle. Thus, DHLA prevents vitamins E and C deficiencies possibly through increasing intracellular GSH levels (54). Perhaps the most intriguing and complex biological function of DHLA is its proposed effect on antioxidant gene expression via the regulation of the nuclear factor, NF-KB.…”

“…DHLA has been shown to influence both the dissociation of the inhibitory subunit IKB from NF-KB complex and the binding of the activated N F-KB (p50 and p65) to DNA (for a brief summary, readers are referred to the next section). The overall effect could be either stimulatory or inhibitory depending on the redox state of the cell and the relative concentrations of o~-Iipoic acid and DHLA (14,54).…”