Radiation is an important modality in cancer treatment and estimates are that between one third and one half of all patients will require ionizing irradiation therapy during some point in their clinical management. However, the radiation-induced damage to the normal tissues restricts the therapeutic doses of radiation that can be delivered to tumors and thereby limits the effectiveness of the treatment. The use of chemical compounds (radioprotectors) represents an obvious strategy to improve the therapeutic index in radiotherapy. However, most of the synthetic radioprotective compounds studied have shown inadequate clinical application owing to their inherent toxicity and high cost. These observations necessitated a search for alternative agents that are less toxic and highly effective.
Studies in the recent past have shown that some medicinal plants possess radioprotective effects. Two species of the commonly used aromatic herb mint, Mentha piperita and M. arvensis protected mice against the γ-radiation-induced sickness and mortality. Detail investigations have also shown that the aqueous extract of M. piperita protected the vital radiosensitive organs: the testis, gastrointestinal and hemopoetic systems in mice. The radioprotective effects are possibly due to free radical scavenging, antioxidant, metal chelating, anti-inflammatory, antimutagenic, and enhancement of the DNA repair processes. This review for the first time summarizes the observations and elucidates the possible mechanisms responsible for the beneficial effects. The lacunae in the existing knowledge and directions for future research are also addressed.
