Natural β-carotene and whole body irradiation in rats

Abstract

beta-carotene and other carotenoids are reported to be potent free radical quenchers, singlet oxygen scavengers, and lipid antioxidants. Whole-body irradiation is known to cause an immunosuppression effect in mammals through the possible initiation and production of reactive oxygen species. We decided to test the possible antioxidative effect against whole-body irradiation of a natural beta-carotene, composed of equal amounts of the all-trans and 9-cis isomers, obtained from the unicellular alga Dunaliella bardawil. Rats were fed on ground commercial food enriched with natural beta-carotene (50 mg/kg diet). On completion of 1 week with beta-carotene, the rats were exposed to a single dose of 4 Gy whole-body irradiation, after which their livers and blood were removed for beta-carotene and retinol analysis in comparison with control livers of animals irradiated or not, or supplemented with beta-carotene after irradiation. A normal increase in body weight with no ill effects was noted in the groups of rats whose diet was supplemented by beta-carotene before and after irradiation, compared with the reduction in the specific growth rate in the group of rats irradiated without beta-carotene. Liver beta-carotene and retinol decreased significantly after irradiation compared with the rats which were not irradiated. This decrease was not shown in rats fed beta-carotene prior to irradiation, and the effect of irradiation was partially cured by supplementation with beta-carotene after irradiation. High-pressure liquid chromatography (HPLC) analysis of the irradiated animals showed a selective decline in 9-cis beta-carotene and in retinol over all-trans beta-carotene and retinyl-esters. These results suggest that 9-cis beta-carotene and retinol protect in vivo against the cellular damage by free radicals induced after whole-body irradiation.

Antimutagenic and radioprotective activities of beta-carotene against the biological effects of iodine-131 radiopharmaceutical in Wistar rats

“…These results are consistent with those from the study by Ben-Amotz et al (1996), who observed the radioprotective activity of BC for 1 week in rats exposed to gamma rays; this carotenoid protected the liver and blood cells of animals against free radical damage induced by radiation. In addition, El-Habit et al (2000) demonstrated the protective role of BC in rats at a concentration of 5 mg/kg bw against mutations induced by cesium-137 gamma radiation when BC was administered for 7 days before exposure to radiation.…”

“…BC, a pigment naturally found in many fruits and vegetables, has one of the highest antioxidant potentials found among carotenoids (Ben-Amotz et al, 1996). Because of the antioxidant and antigenotoxic properties of BC, it is being studied as a radioprotective agent in vitro (Konopacka and Rzeszowska-Wolny, 2001;Ortmann et al, 2004) and in vivo (Salvadori et al, 1996;Konopacka et al, 1998;El-Habit et al, 2000;Sisodia et al, 2004).…”

Combination of Vitamin E with a Carotenoid:α-Tocopherol and Trolox Linked toβ-Apo-8′-carotenoic Acid

“…[81] These properties are also shown by carotenoids [2,82,83] and vitamin E. [24,84] Etherlipid 10 may therefore represent a compound in which these qualities are combined.…”

Exacerbative role of vitamın A on radiation damage in vivo

“…Also vitamin A is being increasingly recognized as an antioxidant that either diminishes or prevents the injurious effects of ROS and RNS (Levenson et al, 1984;Lipmann, 1987;Shaheen and Hassan, 1994;Ben-Amotz et al, 1996;Mannick et al, 1996). In our Fig.…”