Preventive effects of Glycyrrhizae radix extract on estrogen-related endometrial carcinogenesis in mice

Short- and long-term experiments were conducted to examine the effects of G lycyrrhizae radix (Gl radix) extract on mouse endometrial carcinogenesis. G l radix treatment (2 weeks) decreased the levels of c-fos/jun mRNA and the corresponding oncoproteins induced by estradiol-17 beta (E-2) in castrated mice uteri, as determined by reverse transcription-polymerase chain reactio n and Southern blot analysis, and immunohistochemical methods, respectively . For the long-term assays, 98 female ICR mice were given N-methyl-N-nitros ourea (MNU) solution (1 mg/100 g body wt,) and normal saline (as controls) into their left and right uterine corpora, respectively. They were divided into four groups as follows: group 1 was given 0.625% Gl radix- and 5 ppm E -2-containing diet; group 2, 5 ppm E-2-containing diet; group 3, 0.625% Gl radix-containing diet; and group 4, the basal diet alone. Gl radix treatmen t significantly decreased uterine weights and the incidences of uterine end ometrial atypical hyperplastic and malignant lesions, It is suggested that Gl radix has inhibitory effects on E-2-related endometrial carcinogenesis i n mice, through suppression of estrogen-induced c-fos/jun-expressions.