SUPPRESSION BY KAMPO MEDICINES IN PRENEOPLASTIC MAMMARY HYPERPLASTIC ALVEOLAR NODULES OF SHN VIRGIN MICE

Sho-saiko-to (SST), Keishi-bukuryo-gan (KBG), and Shakuyaku-kanzo-to ( SKT) are Japanese modified traditional Chinese herbal medicines (Kampo medicines) consisting of 7, 5, and 2 medical plants, respectively. It is known that the hyperplastic alveolar nodule (HAN) is a representat ive preneoplastic state in the mammary glands of mice. We examined the effects of SST, KBG, and SKT on the formation and growth of HAN in a high-mammary-tumor strain of SHN virgin mice. Oral administration of S ST for 60 days beginning at 90 days of age reduced the number and area of HAN and mammary thymidylate synthetase activity with a reduction o f serum prolactin level. There was little difference between the other experimental groups and the control in the formation and growth of HA N and the enzyme activities. These results indicate that SST may have a preventive effect on malignant mammary transformations.