Radiotherapy, a therapeutic modality of cancer treatment, non-selectively damages normal tissues over tumor tissue as well. A continuous search is going on for the development of therapeutic agents, which selectively reduce radiation induced normal tissue injury without reducing tumoricidal effect, thereby increasing therapeutic ratio of radiation therapy. Our laboratory established 5-(4-methylpiperazin-1-yl)-2-[2'-(3,4-dimethoxyphenyl)-5'benzimidazolyl] benzimi-dazole (DMA) as non-cytotoxic radioprotector in mammalian cells. DMA showed an excellent radioprotection in mice at single nontoxic oral dose by a dose reduction factor (DRF) of 1.28. ORAC assay confirmed its free radical quenching ability. Single bolus dose and 28-days repeated administration of DMA in mice for toxicity studies determined LD50 of >2000 mg/kg bw and 225 mg/kg bw respectively, suggesting DMA is safe.

 

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