Amelioration of radiation-induced damages in mice by carotenoid meso-zeaxanthin.
OBJECTIVE
The present study was undertaken to evaluate the radioprotective effect of meso-zeaxanthin, a xanthophyll carotenoid with profound antioxidant activity.


METHODS
Swiss albino mice were treated with different doses of meso-zeaxanthin (50 and 250 mg/kg body weight, orally) five days before irradiation and sacrificed at different time points. The protective effects of meso-zeaxanthin on mortality, haematological parameters, bone marrow cellularity and gastrointestinal system of irradiated mice were studied. The anti-genotoxic action of meso-zeaxanthin was studied by measuring micronuclei formation, chromosomal aberrations and DNA damage (comet assay).


RESULTS
Meso-zeaxanthin administration significantly increased the lifespan of irradiated mice and reduced myelosuppression as evident from increases in white blood cell counts, bone marrow cellularity and the number of maturing monocytes when compared to the myelosuppression in radiation control animals. Meso-zeaxanthin significantly elevated the radiation-induced reduction in the activities of superoxide dismutase, catalase, glutathione peroxidase and glutathione in both liver and intestinal mucosa. The carotenoid-treated animals showed a profound reduction in genotoxic activity which was apparent in decreases in micronuclei formation and chromosomal aberrations. Irradiation also induced damage to cellular DNA as was obvious from increases in comet parameters like tail DNA%, tail moment, tail length and Olive tail moment in the radiation control group. These parameters were decreased by meso-zeaxanthin treatment.


CONCLUSIONS
Results indicated a radioprotective potential of meso-zeaxanthin.
Amala Cancer Research Centre, Amala Nagar, Kerala.
Alikkunjhi P
AP
Firdous
Edakkadath R
ER
Sindhu
Viswanathan
V
Ramnath
Ramadasan
R
Kuttan
D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D002869:Chromosome Aberrations; D053960:DNA Breaks; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays / Q000009:adverse effects; D041981:Gastrointestinal Tract / Q000187:drug effects / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects; D005978:Glutathione / Q000378:metabolism; D006410:Hematopoiesis / Q000187:drug effects / Q000528:radiation effects; D015227:Lipid Peroxidation / Q000187:drug effects / Q000528:radiation effects; D008136:Longevity / Q000187:drug effects / Q000528:radiation effects; D008297:Male; D051379:Mice; D015162:Micronucleus Tests; D011833:Radiation Injuries, Experimental / Q000517:prevention & control*; D011837:Radiation-Protective Agents / Q000494:pharmacology*; D015431:Weight Loss / Q000187:drug effects / Q000528:radiation effects; D024341:Xanthophylls / Q000494:pharmacology*; D065146:Zeaxanthins
D000975:Antioxidants; D011837:Radiation-Protective Agents; D024341:Xanthophylls; D065146:Zeaxanthins; C584722:meso-zeaxanthin; D005978:Glutathione