Radiation protection by the ocimum flavonoids orientin and vicenin: Mechanisms of action

Uma Devi, P and Ganasoundari, A and Vrinda, B and Srinivasan, KK and Unnikrishnan, MK (2000) Radiation protection by the ocimum flavonoids orientin and vicenin: Mechanisms of action. Radiation Research, 154. pp. 455-460.

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In previous studies, flavonoids, orientin and vicenin, that were isolated from the leaf extract of Ocimum sanctum, were found to protect mice against radiation injury. Several flavonoids are known to be good antioxidants. Therefore, the effect of orientin and vicenin on radiation-induced lipid peroxidation in vivo and their antioxidant activity in vitro were studied. Adult mice were injected intraperitoneally with 50 ,pg/kg of orientin or vicenin and exposed whole-body to 3 Gy of y radiation. Lipid peroxidation was measured in the liver 15 min to 8 h postirradiation. The antioxidant activity of orientin/ vicenin (10-500 pJM) was studied by measuring inhibition of hydroxyl radicals generated by the Fenton reaction (Fe3+-EDTA-ascorbic acid-H202) in vitro. The compounds were also tested for possible pro-oxidant and iron chelation activities at the above concentrations in the in vitro system.Orientin and vicenin provided almost equal protection against radiation-induced lipid peroxidation in mouse liver. Both compounds showed a significantly greater free radical-inhibiting activity in vitro than DMSO. Neither orientin nor vicenin showed any pro-oxidant activity at the concentrations tested. Both compounds inhibited free radical formation in the absence of EDTA. Free radical scavenging appears to be a likely mechanism of radiation protection by these flavonoids

Item Type: Article
Subjects: Pharmacy > MCOPS Manipal > Pharmacology
Depositing User: KMC Manipal
Date Deposited: 13 Jul 2011 04:27
Last Modified: 13 Jul 2011 04:28
URI: http://eprints.manipal.edu/id/eprint/528

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