The effects of resveratrol and selected metabolites on the radiation and antioxidant response.
Excess reactive oxygen species (ROS) generated from ionizing radiation (IR) or endogenous sources like cellular respiration and inflammation produce cytotoxic effects that can lead to carcinogenesis. Resveratrol (RSV), a polyphenol with antioxidant and anticarcinogenic capabilities, has shown promise as a potential radiation modifier. The present study focuses on examining the effects of RSV or RSV metabolites as a radiation modifier in normal tissue. RSV or a RSV metabolite, piceatannol (PIC) did not protect human lung fibroblasts (1522) from the radiation-induced cell killing. Likewise, neither RSV nor PIC afforded protection against lethal total body IR in C3H mice. Additional research has shown protection in cells against hydrogen peroxide when treated with RSV. Therefore, clonogenic survival was measured in 1522 cells with RSV and RSV metabolites. Only the RSV derivative, piceatannol (PIC), showed protection against hydrogen peroxide mediated cytotoxicity; whereas, RSV enhanced hydrogen peroxide sensitivity at a 50 µM concentration; the remaining metabolites evaluated had little to no effect on survival. PIC also showed enhancement to peroxide exposure at a higher concentration (150 µM). A potential mechanism for RSV-induced sensitivity to peroxides could be its ability to block 1522 cells in the S-phase, which is most sensitive to hydrogen peroxide treatment. In addition, both RSV and PIC can be oxidized to phenoxyl radicals and quinones, which may exert cytotoxic effects. These cytotoxic effects were abolished when HBED, a metal chelator, was added. Taken together RSV and many of its metabolic derivatives are not effective as chemical radioprotectors and should not be considered for clinical use.
Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD, USA. fabrek@mail.nih.gov
Kristin M
KM
Fabre
Keita
K
Saito
William
W
DeGraff
Anastasia L
AL
Sowers
Angela
A
Thetford
John A
JA
Cook
Murali C
MC
Krishna
James B
JB
Mitchell
D000818:Animals; D000975:Antioxidants / Q000378:metabolism / Q000494:pharmacology*; D002453:Cell Cycle / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D004305:Dose-Response Relationship, Drug; D004492:Edetic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D005260:Female; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D006801:Humans; D006861:Hydrogen Peroxide / Q000633:toxicity; D051379:Mice; D008809:Mice, Inbred C3H; D018384:Oxidative Stress / Q000187:drug effects; D010636:Phenols / Q000378:metabolism; D011809:Quinones / Q000378:metabolism; D011837:Radiation-Protective Agents / Q000378:metabolism / Q000494:pharmacology*; D000077185:Resveratrol; D013267:Stilbenes / Q000378:metabolism / Q000494:pharmacology*; D014916:Whole-Body Irradiation; D020122:tert-Butylhydroperoxide / Q000633:toxicity
D000975:Antioxidants; D010636:Phenols; D011809:Quinones; D011837:Radiation-Protective Agents; D013267:Stilbenes; C042329:phenoxy radical; C037740:N,N'-bis(2-hydroxybenzyl)ethylenediamine-N,N'-diacetic acid; C041525:3,3',4,5'-tetrahydroxystilbene; D020122:tert-Butylhydroperoxide; D004492:Edetic Acid; D006861:Hydrogen Peroxide; D000077185:Resveratrol