Extract of Curcuma longa in the treatment of radiation lesions

Reactive oxygen species (ROS) have been indicated in the development of diseases such as cancer, cardiovascular diseases, degenerative diseases and ageing. An increasing body of evidence indicates an association between increased and persistent oxidative stress and the development of radiation damage in tissues such as skin, central nervous system and kidney. On the basis of the new hypothesis i.e. the involvement of oxidative stress in the development of radiation-induced normal tissue lesions, an antioxidant drug has been developed. This consists of Curcumin and vitamin E. Curcumin is a phenolic antioxidant and anti-inflammatory initially isolated from the rhizome of the plant Curcuma longa Linn. It inhibits lipid peroxidation including radiation-induced lipid peroxidation. The efficacy of this combination drug has been tested in a number of biological models of radiation damage. This drug significantly reduced the incidence of radiation-induced myelopathy in a rat model. Radiation myelopathy is a rare but severe normal tissue damage that develops as a result of demyelination of individual nerve fibres. The lesions progresses with demyelination and eventual white matter necrosis that results in paralysis. In addition, the drug significantly reduces the incidence of radiation-induced mucositis. With single doses of radiation, a significant dose modification factor (DMF) of 1.24±0.06 was obtained. Radiation-induced mucositis of upper aerodigestive tract is a major dose-limiting factor in the treatment of head and neck tumours that develops as a consequence of the depletion of the stem cells of the epithelial lining of the mucosa. With a more clinically relevant fractionated irradiation schedule, the DMF increases to a remarkably high level of 1.44±0.08. It is concluded that the antioxidant compound consisting of the extract of Curcuma longa and ? ?-tocopherol has great potentials in the treatment of radiation-induced normal tissue lesions.