• DOI:10.1021/JF052651Q
• Corpus ID: 22714529

Astaxanthin protects against oxidative stress and calcium-induced porcine lens protein degradation.

@article{Wu2006AstaxanthinPA,
  title={Astaxanthin protects against oxidative stress and calcium-induced porcine lens protein degradation.},
  author={Tzu-Hua Wu and Jiahn-Haur Liao and Wen-Chi Hou and Fu Yung Huang and Timothy J. Maher and Chao‐Chien Hu},
  journal={Journal of agricultural and food chemistry},
  year={2006},
  volume={54 6},
  pages={
          2418-23
        }
}

• Tzu-Hua Wu, J. Liao, +3 authors Chao‐Chien Hu
• Published 22 March 2006
• Biology
• Journal of agricultural and food chemistry

Astaxanthin (ASTX), a carotenoid with potent antioxidant properties, exists naturally in various plants, algae, and seafoods. In this study, we investigated the in vitro ability of ASTX to protect porcine lens crystallins from oxidative damage by iron-mediated hydroxyl radicals or by calcium ion-activated protease (calpain), in addition to the possible underlying biochemical mechanisms. ASTX (1 mM) was capable of protecting lens crystallins from being oxidized, as measured by changes in tryptophan fluorescence, in the presence of a Fenton reaction solution containing 0.2 mM Fe2+ and 2 mM H2O2. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis demonstrated that beta(high)-crystallin was the most vulnerable protein under these conditions of free radical exposure. The proteolysis of lens crystallins induced by calcium ion-activated calpain was also inhibited by ASTX (0.03-1 mM) as determined by daily measurement of the light-scattering intensity at 405 nm for five consecutive days. ASTX at 1 mM was as potent as a concentration of 0.1 mM calpain inhibitor E64 in protecting the oxidative damage/hydrolysis of porcine crystallins. At a concentration of 1 mM, ASTX provided better protection than the endogenous antioxidant glutathione in terms of suppressing calcium-induced turbidity of lens proteins. Thin-layer chromatography analysis indicated that ASTX interacted with calcium ions to form complexes, which we believe interfere with the hydrolysis of lens crystallins by calcium-activated calpain. This in vitro study shows that ASTX is capable of protecting porcine lens proteins from oxidative insults and degradation by calcium-induced calpain.