Antioxidant activity is considered to be one of the major mechanisms by which many plants and phytochemicals are reported to offer radioprotection . The potent antioxidant compounds present in the decoction may therefore be mainly responsible for the protective effect demonstrated by this herbal drug against bleomycin induced DNA damage in normal peripheral lymphocytes. The antioxidant potency of this polyherbal preparation is probably due to the collective contribution of antioxidant compounds present in the individual plant components used in its preparation. Thus, previous in vivo studies demonstrate that N. sativa seed oil can significantly reduce blood oxidative stress markers of rats exposed to a single dose of 6 Gy radiation . Similarly, extracts of H. indicus that can protect against radiation induced strand breaks in plasmid DNA have also been shown to protect against oxidative stress induced lipid peroxidation . Although these studies demonstrate the ability of the individual plants in the decoction to reduce oxidative stress, none of them have evaluated the ability of these plants to protect against cytogenetic damage induced by chemotherapy alone or in combination with radiotherapy.