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

P. Uma Devi, A. Ganasoundari, B. Vrinda, K. K. Srinivasan, M. K. Unnikrishnan

Research output: Contribution to journalArticlepeer-review

211 Citations (Scopus)


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 μg/kg of orientin or vicenin and exposed whole-body to 3 Gy of γ radiation. Lipid peroxidation was measured in the liver 15 min to 8 h postirradiation. The antioxidant activity of orientin/vicenin (10-500 μM) was studied by measuring inhibition of hydroxyl radicals generated by the Fenton reaction (Fe3+-EDTA-ascorbic acid-H2O2) 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. (C) 2000 by Radiation Research Society.

Original languageEnglish
Pages (from-to)455-460
Number of pages6
JournalRadiation Research
Issue number4
Publication statusPublished - 01-01-2000
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Biophysics
  • Radiation
  • Radiology Nuclear Medicine and imaging


Dive into the research topics of 'Radiation protection by the Ocimum flavonoids orientin and vicenin: Mechanisms of action'. Together they form a unique fingerprint.

Cite this