Antioxidant Inhibition of Skin Inflammation Induced by Reactive Oxidants: Evaluation of the Redox Couple Dihydrolipoate/Lipoate

Abstract

Reactive oxygen species play an important role in mediating skin inflammation, and antioxidants may provide protection. We investigated the anti-inflammatory activity of natural antioxidants, such as superoxide dismutase, catalase, trolox (a water-soluble tocopherol analog) and the redox couple dihy-drolipoate/lipoate in skin. Furthermore we compared the anti-inflammatory potency of natural R and racemic dihydroli-poate, as well as R and S lipoate. Skin inflammation in hairless mice was induced by intradermal injection of the hydrogen peroxide producing enzyme glucose oxidase (GOD) or by topical application of the prooxidant drug anthralin. Intradermal injection of the antioxidants inhibited skin inflammation caused by GOD (catalase, dihydrolipoate) and anthralin (trolox, superoxide dismutase, dihydrolipoate). There was no statistically significant difference between the anti-inflammatory activity of the natural R and racemic dihydrolipoate. R or S lipoate did not inhibit skin inflammation when injected intradermally. In feeding experiments, however, R lipoate significantly inhibited GOD-mediated skin inflammation, while S lipoate was only marginally protective. We conclude that (1) several natural antioxidants such as catalase, superoxide dismutase and dihydrolipoate have anti-inflammatory properties in dermatitis induced by reactive oxidants, (2) lipoate (oxidized dihydrolipoate) has skin anti-inflammatory activity when administered orally and (3) naturally occurring R lipoate is a more potent anti-inflammatory agent than the non-physiological S lipoate.

Influence of blood serum selenium on udder health in dairy cows

“…Superoxide dismutase, glutathione peroxidase and catalase in the mammary cells remove superoxide and peroxides before they react with the metal catalyst and create compounds that are destructive and toxic to cells. This intracellular defense mechanism leads to damage of the mammary gland during the acute phase of inflammation (Ndiveni et al, 1991;Fuchs and Milbradt, 1994).…”

Antioxidants attenuate anthralin-induced skin inflammation in BALB/c mice: role of specific proinflammatory cytokines

“…To prevent oxygen radical-derived tissue injury, the hydrophilic antioxidant PEG-SOD (500 U/kg; 0.2 mL vol) and the GSH precursor NAC (200,1000 mg/kg) were dissolved in sterile water and injected intravenously 1 h before anthralin challenge. PEG-SOD equilibrates with extravascular spaces and is gradually removed over 72 h [16], whereas unmodified enzyme is completely removed from circulation within 4 h [17]. Groups of mice were administered 100 or 200 U/kg of vitamin E by gavage in a 0.2-mL vol of olive oil for 10 consecutive days before anthralin challenge on the next day.…”

“…Groups of mice were administered 100 or 200 U/kg of vitamin E by gavage in a 0.2-mL vol of olive oil for 10 consecutive days before anthralin challenge on the next day. The concentrations of antioxidants tested were within the range of previously reported murine models of oxidant-mediated toxicity [18][19][20]. Ear thickness measurements were made using an Oditest precision caliper, model D1000 (Dyer Co., Lancaster, PA) at Ϫ1, 6, 24, 48, 72, and 96 h after anthralin challenge.…”

Physicochemical Characteristics, Cytotoxicity, and Antioxidant Activity of Three Lipid Nanoparticulate Formulations of Alpha-lipoic Acid

“…However, systemic delivery of antioxidants to the target site is still inefficient; topical application could be beneficial if sufficient quantities of the substance penetrate the skin. According to Fuchs and Milbradt, both intracutaneously injected DHLA and orally administered LA are effective in skin protection against inflammation (12). Therefore, topical application of exogenous LA could be one of the possible approaches to enhance antioxidation defense in human (13,14).…”