STUDIES ON MECHANISMS AND BLOCKADE OF CARCINOGENIC ACTION OF FEMALE SEX-HORMONES

Tumours of mice are induced by administration of Inj. Hydroxyprogester oni Caproatis Co. (EP) in a practical subthreshold dose of carcinogene sis or 2.5-5 times the human contraceptive dose (simply referred to as 2.5- to 5-fold dose) combined with whole-body 0.5 Gy gamma-ray irradi ation. Malignant transformation of Syrian golden hamster embryo (SHE) cells is also induced by 5-fold dose of EP combined with 0.3 Gy gamma- ray irradiation in vitro, thereby indicating that synergistic carcinog enesis can be obtained by combined use of physical and chemical carcin ogens. The mechanisms of synergistic carcinogenesis have been further explained by cytogenetics, damage extent of the target cell DNA and pr oduction of free radicals. The Chinese traditional medicine with antio xidating effect (Sulekang Capsule, SC), food additive-butylated hydrox yanisole (BHA) and green tea can effectively inhibit the carcinogenic effect of EP or EP combined with gamma rays in mice. They all have mar ked ability to scavenge or remove the free radicals and thereby reduce the DNA damage.