Radioprotective effects of manganese-containing superoxide dismutase mimics on ataxia-telangiectasia cells.

Published

Journal Article

We tested several classes of antioxidant manganese compounds for radioprotective effects using human lymphoblastoid cells: six porphyrins, three salens, and two cyclic polyamines. Radioprotection was evaluated by seven assays: XTT, annexin V and propidium iodide flow cytometry analysis, gamma-H2AX immunofluorescence, the neutral comet assay, dichlorofluorescein and dihydroethidium staining, resazurin, and colony survival assay. Two compounds were most effective in protecting wild-type and A-T cells against radiation-induced damage: MnMx-2-PyP-Calbio (a mixture of differently N-methylated MnT-2-PyP+ from Calbiochem) and MnTnHex-2-PyP. MnTnHex-2-PyP protected WT cells against radiation-induced apoptosis by 58% (p = 0.04), using XTT, and A-T cells by 39% (p = 0.01), using annexin V and propidium iodide staining. MnTnHex-2-PyP protected WT cells against DNA damage by 57% (p = 0.005), using gamma-H2AX immunofluorescence, and by 30% (p < 0.01), using neutral comet assay. MnTnHex-2-PyP is more lipophilic than MnMx-2-PyP-Calbio and is also >10-fold more SOD-active; consequently it is >50-fold more potent as a radioprotectant, as supported by six of the tests employed in this study. Thus, lipophilicity and antioxidant potency correlated with the magnitude of the beneficial radioprotectant effects observed. Our results identify a new class of porphyrinic radioprotectants for the general and radiosensitive populations and may also provide a new option for treating A-T patients.

Full Text

Duke Authors

Cited Authors

  • Pollard, JM; Reboucas, JS; Durazo, A; Kos, I; Fike, F; Panni, M; Gralla, EB; Valentine, JS; Batinic-Haberle, I; Gatti, RA

Published Date

  • August 2009

Published In

Volume / Issue

  • 47 / 3

Start / End Page

  • 250 - 260

PubMed ID

  • 19389472

Pubmed Central ID

  • 19389472

Electronic International Standard Serial Number (EISSN)

  • 1873-4596

International Standard Serial Number (ISSN)

  • 0891-5849

Digital Object Identifier (DOI)

  • 10.1016/j.freeradbiomed.2009.04.018

Language

  • eng