The effects of Boehmeria nivea (L.) Gaud. on embryonic development: In vivo and in vitro studies

Boehmeria nivea (L.) Gaud. was commonly used to treat miscarriages clinically. The aim of this study was to examine its safety for embryonic development. Pregnant mice were randomly assigned into 5 groups, i.e. mice were oral-treated with distilled water (G1), with Boehmeria nivea extract of 2, 8 or 32 g/kg/day (G2, G3 or G4), and with 3 doses of vitamin A of 200,000 IU/kg as positive controls (G5). Meanwhile, IC50 values for both embryonic stem cells (ESCs) and 3T3 cells were detected by cytotoxicity assays. (1) The resorptions and malformed fetuses in G5 were significantly higher than G1 (P < 0.001), whereas the maternal body-weight and uterus-weight were lower than G1 (P < 0.05); (2) there was no difference in the fetal body-weight, maternal relative body-weight gain, liver-, kidney- or heart-weight, relative organ-weight, and histological examination among five groups; (3) there was no difference in IC50 values between ESCs and 3T3 cells, but high concentration of Boehmeria nivea extract might significantly lower ESCs’ viability (P < 0.05). Boehmeria nivea extract at 32 g/kg/day did not cause significant embryotoxicity or maternal toxicity in mice, although it might cause cytotoxicity in cultured ESCs at a high dose.