The Possible Mechanisms Involved in the Protection Strategies against Radiation-Induced Cellular Damage by Carnitines

There is constant low level background radiation from the cosmos but in certain situation the body may be subjected to increased acute or chronic exposure from other sources. This occurs in situations such as radiation accidents, medical use and could possibly occur in military/terrorist incident. Dependent on the type, strength of the actual source, degree of exposure and type of radiation different strategies may be employed to reduce damage to the body tissues. A number of pharmacological agents such as peroxisome proliferator-activated receptor (PPAR) gamma agonists, diltiazem, amifostine and palifermin as well as antioxidants and metabolic compounds have been shown to be effective in preventing and also in reducing the long-term damage of the exposure of the living cells to radiation. The major drawback of synthetic (pharmacological) compounds has been that they are highly toxic at the optimum protective dose. Studies have shown that various endogenously found compounds such as L-carnitine, and its derivative acetyl-L-carnitine, are able to protect tissues and organs against various forms of toxic insult including radiation damage. The radiation-induced chronic injury may also be counteracted by other metabolic compounds with amine groups and antioxidant properties similar to the carnitines such as cysteine, 3,3’-diindolylmethane (DIM) and N-acetylcysteine. This review discuses the radioprotective compounds as well as the potential mechanism of cellular protection against radiation by carnitines and other compounds.