DECREASED TUMOR-INCIDENCE AND INCREASED SURVIVAL BY ONE-YEAR ORAL LOW-DOSE ARGININE SUPPLEMENTATION IN THE MOUSE

The effects of arginine on tumor growth, antitumor mechanisms and a po tential therapeutic role have been reviewed recently. In these studies , however controversial they were, high dose protocols for arginine tr eatment have been applied. Based upon own recent findings that low dos e arginine stimulates the immune system and blocks lipid peroxidation, we performed preventive treatment with low dose (50 mg/kg body weight per day, orally administered) L-arginine in 150 mice for a period of one year. We compared survival and total number of tumors at the end o f the feeding period to that found in 150 mice given taurine in the sa me dosage and in 150 mice without treatment. Survival of the arginine treated group was statistically significant as compared to that of the control group without treatment (p<0.05): 116 mice were alive in the control group, 122 in the group administered taurine and 132 in the ar ginine treated group. The total number of tumors was significantly low er in the arginine treated group vs. the control group (p<0.01). The t otal number of malign and benign tumors was significantly lower in the arginine treated group, whereas taurine significantly reduced the num ber of benign tumors only (p<0.05). Arginine and taurine stimulate the immune system at the lymphocyte level. Arginine also acts at the macr ophage level, inducing nitric oxide mediated cytotoxicity against tumo r cells. Both compounds are known to block the formation of lipid pero xidation products. We therefore suggest that these two mechanisms are responsible for the decreased total number of tumors and the concomita nt increase in survival.