CAFFEINE POTENTIATES OR PROTECTS AGAINST RADIATION-INDUCED DNA AND CHROMOSOMAL DAMAGE IN HUMAN-LYMPHOCYTES DEPENDING ON TEMPERATURE AND CONCENTRATION

The effect of caffeine on radiation-induced chromosomal aberrations an d DNA strand breaks in unstimulated human lymphocytes was investigated . When present prior to and during the radiation exposure, caffeine tr eatment was found to cause either potentiation or protection against i nduction of chromosomal aberrations depending on the concentration and temperature. When the nucleoid sedimentation technique was applied, e nhancement or reduction of radiation-induced DNA strand breaks by caff eine was also found to be dependent on temperature and caffeine concen tration. It is proposed that caffeine, in addition to its suspected ab ility to influence DNA repair, can also influence the induction of DNA damage, leading to alterations in the yield of chromosomal aberration s.