Redox properties and cytoprotective actions of atranorin, a lichen secondary metabolite.
Atranorin (ATR) is a lichenic secondary metabolite with potential uses in pharmacology. Antinociceptive and antiinflammatory actions have been reported, and the use of atranorin-enriched lichen extracts in folk medicine is widespread. Nonetheless, very few data on ATR biological actions are available. Here, we evaluated free radical scavenging activities and antioxidant potential of ATR using various in vitro assays for scavenging activity against hydroxyl radicals, hydrogen peroxide, superoxide radicals, and nitric oxide. The total reactive antioxidant potential (TRAP) and total antioxidant reactivity (TAR) indexes and in vitro lipoperoxidation were also evaluated. Besides, we determined the cytoprotective effect of ATR on H(2)O(2)-challenged SH-SY5Y cells by the MTT assay. ATR exerts differential effects towards reactive species production, enhancing hydrogen peroxide and nitric oxide production and acting as a superoxide scavenger; no activity toward hydroxyl radical production/scavenging was observed. Besides, TRAP/TAR analysis indicated that atranorin acts as a general antioxidant, although it demonstrated to enhance peroxyl radical-induced lipoperoxidation in vitro. ATR was not cytotoxic, and also protected SH-SY5Y cells against H(2)O(2)-induced cell viability impairment. Our results suggest that ATR has a relevant redox-active action, acting as a pro-oxidant or antioxidant agent depending on the radical. Also, it will exert cytoprotective effects on cells under oxidative stress induced by H(2)O(2).
Departamento de Fisiologia, Universidade Federal de Sergipe, São Cristóvão, Sergipe, Brazil.
Marcelia Garcez Dória
MG
Melo
João Paulo Almeida
JP
dos Santos
Mairim Russo
MR
Serafini
Fernanda Freitas
FF
Caregnato
Matheus Augusto de Bittencourt
MA
Pasquali
Thallita Kelly
TK
Rabelo
Ricardo Fagundes
RF
da Rocha
Lucindo
L
Quintans
Adriano Antunes de Souza
AA
Araújo
Francilene Amaral
FA
da Silva
José Cláudio Fonseca
JC
Moreira
Daniel Pens
DP
Gelain
D000975:Antioxidants / Q000494:pharmacology*; D002478:Cells, Cultured; D019610:Cytoprotection; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D062385:Hydroxybenzoates / Q000494:pharmacology*; D010084:Oxidation-Reduction
D000975:Antioxidants; D062385:Hydroxybenzoates; C026304:atranorin; D006861:Hydrogen Peroxide