Anti-abortive effect of Radix scutellariae and Rhizoma atractylodis in mice.

The objective of this study is to investigate the significance of natural killer (NK) cells and interleukin-2 in uterus in the early embryo loss (or resorption), and to elucidate the immunological modulation of maternal-fetal interface with Chinese herbal medicine Radix scutellariae (huang qin) and Rhizoma atractylodis (bai zhu). Lipopolysaccharide (LPS) was given via the tail vein to induce abortion in mice at day 7 of gestation. Uterine NK cells and IL-2 contents were analyzed by immunohistochemistry and enzyme linked immunosorbent assay (ELISA), respectively. The number of NK cells was found to be much higher (mean = 180 +/- 39) in the decidua of LPS-treated abortion mice. But when the Chinese herbal medicine was used to prevent LPS-induced abortion, less NK cells (mean = 11 +/- 4) were counted (p < 0.01). The mean value of IL-2 in LPS-treated mice was 5.25 +/- 2.5938 pg/mg protein, higher than (p < 0.05) that of the herb prevention group, which was only 1.86 +/- 0.9789 pg/mg protein. The results therefore indicate that the increase of NK cells in the decidua and IL-2 contents in the uterus in LPS-treated mice is closely related to the embryo loss, and that the Chinese herbal medicine prescription composed of Radix scutellariae and Rhizoma atractylodis has an anti-abortive effect through inhibition of maternal-fetal interface immunity.