Potent Induction of Total Cellular and Mitochondrial Antioxidants and Phase 2 Enzymes by Cruciferous Sulforaphane in Rat Aortic Smooth Muscle Cells: Cytoprotection Against Oxidative and Electrophilic Stress

Abstract

Sulforaphane, a cruciferous isothiocyanate compound, upregulates cytoprotective genes in liver, but its effects on antioxidants and phase 2 defenses in vascular cells are unknown. Here we report that incubation of rat aortic smooth muscle A10 cells with sulforaphane (0.25-5 microM) resulted in concentration-dependent induction of a spectrum of important cellular antioxidants and phase 2 enzymes, including superoxide dismutase (SOD), catalase, the reduced form of glutathione (GSH), glutathione peroxidase, glutathione reductase (GR), glutathione S-transferase (GST), and NAD(P)H:quinone oxidoreductase 1 (NQO1). Sulforaphane also increased levels/activities of SOD, catalase, GSH and GST in isolated mitochondria of aortic smooth muscle cells. Time-dependent sulforaphane-induced increases in the mRNA levels for MnSOD, catalase, the catalytic subunit of gamma-glutamylcysteine ligase, GR, GST-A1, GST-P1, and NQO1 were observed. Pretreatment with sulforaphane (0.5, 1, and 5 microM) protected aortic smooth muscle cells from oxidative and electrophilic cytotoxicity induced by xanthine oxidase (XO)/xanthine, H2O2, SIN-1-derived peroxynitrite, 4-hydroxy-2-nonenal, and acrolein. Furthermore, sulforaphane pretreatment prevented intracellular accumulation of reactive oxygen species (ROS) after exposure of the cells to XO/xanthine, H2O2, or SIN-1. Taken together, this study demonstrates that in the aortic smooth muscle cells sulforaphane at physiologically relevant concentrations potently induces a series of total cellular as well as mitochondrial antioxidants and phase 2 enzymes, which is accompanied by dramatically increased resistance of these vascular cells to oxidative and electrophilic stress.

Sulforaphane treatment protects skeletal muscle against damage induced by exhaustive exercise in rats

“…NQO1 also catalyzes the regeneration of oxidized vitamin E, contributing to the maintenance of these important antioxidants (41). It has been demonstrated that NQO1 is strongly induced by SF in different tissues, such as the rat bladder, animal and human mammalian tissues (9,61), and cell lines, such as bronchial epithelial cells, rat aortic smooth muscle cells, and cardiac fibroblasts (48,62,63). To our knowledge, no studies have evaluated whether physical exercise affects NQO1 activity.…”

The Augmenting Activity of 6-(Methylsulfinyl)hexyl Isothiocyanate on Cellular Glutathione Levels Is Less Sensitive to Thiol Compounds Than Its Cytotoxic Activity

“…and those reported by others 3,4) might be due to the cells, but not to the kinds of isothiocyanate compounds used in the experiments. In addition, preferential augmentation of Gclm mRNA expression by 6-MITC was also observed in adherent peritoneal exudate cells.…”

“…1) Further, sulforaphane augments the expression of an antioxidant gene, gamma-glutamate cysteine ligase [1][2][3] and results in a transient decrease in cellular reduced glutathione levels, followed by increases in its levels. 3,4) 6-(Methylsulfinyl)hexyl isothiocyanate (6-MITC) is found in a Japanese pungent spice, wasabi (Wasabia japonica), 5) and has been found to augment the induction of phase2 enzymes, such as quinone reductase (QR) and glutathione S-transferase (GST), by stimulating expression of their genes. 6,7) Little work, however, has been done on the effects of 6-MITC on cellular glutathione levels.…”

Neuroprotection through Stimulation of Mitochondrial Antioxidant Protein Expression

“…However, growing evidence suggests that protection against ROS accumulation can occur through increased expression of mitochondrial antioxidant enzymes, e.g., SOD2, or proteins responsible for the biosynthesis of glutathione and for the reduction of NADP + . Levels of SOD2 and mitochondrial glutathione peroxidase and reductase and glutathione are elevated by treatment of aortic smooth muscle cells and cardiac myocytes with sulforaphane [103] or dithiolethione, another organosulfur compound [104]. While these effects have not yet been reported for mitochondria present within neurons or the CNS, preliminary results from our lab support this hypothesis and demonstrate that mitochondria from the brains of rats treated with sulforaphane are resistant to t-butyl hydroperoxide-induced opening of the PTP [71].…”