ANTICARCINOGENIC EFFECT OF THEOPHYLLINE ON THE DEVELOPMENT OF INDUCED-TUMORS IN ANIMALS

Anticarcinogenic activity of pharmaceutical drug Theophylline was stud ied in four models of chemical carcinogenesis. Tumors of the mammary g land, nervous system and kidneys, esophagus and forestomach were induc ed correspondingly by intramammary injections of N-methyl-N-nitrosoure a, transplacental administration of N-ethyl-N-nitrosourea, and peroral intubations of N-nitrososarcosine ethyl ether in rats. Tumors of the uterus cervix and vagina were induced by intravaginal applications of 7,12-dimethylbenz(a) anthracene in mice. Theophylline was given prolon gedly with diet at the concentration of 1 g/kg during the period of tu mor promotion and progression. Theophylline effectively inhibited the development of the mammary gland adenocarcinomas, brain and spinal cor d gliomas, peripheral nerves neurinomas, mesenchimal kidney tumors, es ophageal squamous cell papillomas induced by the above mentioned carci nogens in rats. However, this drug did not affect the development of i nduced squamous cell carcinomas of the uterus cervix and vagina in mic e. The possibilities of using theophylline and other methylxanthines f or cancer chemo-prevention are discussed.