Modulation of Radioresponse by an Isoquinoline Alkaloid Berberine in Cultured HeLa Cells Exposed to Different Doses of γ –Radiation

Ionizing radiations are used regulary to treat various tumors since the discovery of X-rays by Wilhelm Conrad Röntgen in the year 1895 and approximately 40% of patients are cured by radiotherapy and 50% of the patients receive radiotherapy during their disease [1,2]. It is used to treat tumors or as an adjuvant or neoadjuvant therapy and in several instances it is the only modality to treat tumors [3]. It is also used as a palliative therapy if the treatment is impossible [4,5]. Despite the success of radiotherapy its full potential remains underutilized due to the presence of hypoxic fraction of cells in the tumor and also due to the fact that with the increase in the radiation dose the normal tissue radiotoxicity increases [6]. The normal tissue toxicity can be alleviated and the tumor response to radiotherapy may be increased by combining certain drugs with radiotherapy.