Synergy between sulforaphane and selenium in protection against oxidative damage in colonic CCD841 cells

Wang, Y., Dacosta, C., Wang, W., Zhou, Z., Liu, M. and Bao, Y. (2015) Synergy between sulforaphane and selenium in protection against oxidative damage in colonic CCD841 cells. Nutrition Research, 35(7), pp. 610-617. (doi: 10.1016/j.nutres.2015.05.011) (PMID:26094214)

Abstract

Dietary isothiocyanates are potent inducers of the NF-E2-related factor 2 (Nrf2) pathway. Sulforaphane (SFN), a representative dietary isothiocyanate, has previously been shown to up-regulate antioxidant enzymes such as selenium (Se)-dependent thioredoxin reductase-1 (TrxR-1) in many tumor cell lines. In the present study, we hypothesized that a combination of SFN and Se would have a synergistic effect on the up-regulation of TrxR-1 and the protection against oxidative damage in the normal colonic cell line CCD841. Treatment of cells with SFN and Se significantly induced TrxR-1 expression. Pretreatment of cells with SFN protects against H2O2-induced cell death; this protection was enhanced by cotreatment with Se. The small interfering RNA knockdown of either TrxR-1 or Nrf2 reduced the protection afforded by SFN and Se cotreatment; TrxR-1 and Nrf2 knockdown reduced cell viabilities to 66.5% and 51.1%, respectively, down from 82.4% in transfection-negative controls. This suggests that both TrxR-1 and Nrf2 are important in SFN-mediated protection against free radical-induced cell death. Moreover, flow cytometric analysis showed that TrxR-1 and Nrf2 were involved in SFN-mediated protection against H2O2-induced apoptosis. In summary, SFN activates the Nrf2 signaling pathway and protects against H2O2-mediated oxidative damage in normal colonic cells. Combined SFN and Se treatment resulted in a synergistic up-regulation of TrxR-1 that in part contributed to the enhanced protection against free radical-mediated cell death provided by the cotreatment.

• Item Type: Articles
• Keywords: Cruciferous vegetable, sulforaphane, selenium, thioredoxin reductase, Nrf2, colon cancer.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Dacosta, Dr Christopher
• Authors: Wang, Y., Dacosta, C., Wang, W., Zhou, Z., Liu, M., and Bao, Y.
• College/School: College of Science and Engineering > School of Engineering > Biomedical Engineering
• Journal Name: Nutrition Research
• Journal Abbr.: Nutr Res.
• Publisher: Elsevier
• ISSN: 0271-5317
• ISSN (Online): 1879-0739
• Published Online: 30 May 2015
• Copyright Holders: Copyright © 2015 Elsevier Inc.
• First Published: First published in Nutrition Research 35(7): 610-617
• Publisher Policy: Reproduced in accordance with the publisher copyright policy