Objective: The current study investigates the potential of alcoholic extract of Wrightia tinctoria leaves and its isolates in repairing the DNA damage induced by gamma radiation. Methodology: The ethanolic extract of Wrightia tinctoria (EEWT) the leaves was subjected to in vitro anti oxidant assay by DPPH radical scavenging and hydrogen peroxide scavenging methods. He EEWT was investigated to the Micronucleus assay, spleen colony assay and comet assay in Sprague Dawley rats wherein DNA damage had already been induced by irradiation. Results: The ethanolic extract of Wrightia tinctoria leaves having good antioxidant activity. In the micronucleus assay, a 2 Gy quantum of whole-body gamma radiation significantly enhanced the levels of micronucleated reticulocytes and this induction was substantially reversed in the extract treatment group. Results of the spleen colony assay pointed to the extract’s ability to enhance the recovery of the hematopoietic system, in a dose-dependent manner, following 6 Gy gamma irradiation. The decrease in cellular repair index due to enhanced DNA repair was evident from the comet assay parameters. Moreover, the isolates from ethanolic extract of Wrightia tinctoria, when imperiled to DNA protection by in vitro gamma radiation method in plasmid pBR322 DNA, abetted DNA repair at higher dose. Conclusion: The DNA protection afforded is likely attributable to free radical scavenging properties along with a potential for regenerating the immune system through repair of post irradiated DNA.
Key words: Comet assay, DNA damage, Micronucleus assay, Radioprotective, Spleen colony assay, Wrightia tinctoria.