Research in Pharmaceutical Biotechnology

  • Abbreviation: Res. Pharm. Biotech.
  • Language: English
  • ISSN: 2141-2324
  • DOI: 10.5897/RPB
  • Start Year: 2009
  • Published Articles: 42

Full Length Research Paper

Assessment of radiation-induced DNA damage by comet assay in cultured HeLa cells treated with guduchi (Tinospora cordifolia Miers) before exposure to different doses of g-radiation

G. C. Jagetia
  • G. C. Jagetia
  • Department of Zoology, Mizoram University, Aizawl-796 004, India.
  • Google Scholar
S. K. Rao
  • S. K. Rao
  • Department of Pharmacognosy, C. U. Shah College of Pharmacy and Research, Wadhwan, India.
  • Google Scholar

  •  Accepted: 13 June 2011
  •  Published: 30 July 2011



The radiomodulatory effect of guduchi extract (TCE) was studied in HeLa cells incubated with 0, 1, 2, 4, 6 or 8 µg/ml of TCE for 2 or 4 h before exposure to 0, 0.5, 1, 2, 3 or 4 Gy of g-radiation. The molecular DNA damage was assessed using alkaline comet assay, where DNA tail fragmentation olive tail moment (OTM) served as a measure of DNA damage. Exposure of HeLa cells to 0, 0.5, 1, 2, 3 or 4 Gy g-rays caused a dose-dependent rise in the OTM indicating an increase in the DNA damage at all post-irradiation times. Treatment of HeLa cells with different concentrations of TCE before irradiation increased the OTM significantly at different assessment times, when compared with the concurrent non-TCE treated irradiated control. The greatest DNA damage was observed in cells pretreated with 8 µg/ml TCE, which was approximately 10 folds higher at 16 h for all irradiation doses. The cellular DNA did not exhibit repair of lesions as the DNA damage increased constantly up to 16 h post-irradiation and remained unaltered thereafter. TCE increased the cell killing effects of radiation by increasing the DNA damage and could be an alterantive strategy during radiotherapy of tumors.


Key words: HeLa cells, guduchi, DNA damage,radiation, cell survival.