OBJECTIVETo observe the effect of Cinnabaris on mouse embryos after pregnant mice were treated by Cinnabaris in different periods of pregnancy.

METHODTwo separate experiments were performed: First, Cinnabaris was orally given into pregnant mice at the doses of 0.08, 0.4, 4.0 g x kg(-1) from D6 to D19 after pregnancy; Second, Cinnabaris was orally given into mice at the same doses mentioned above from D14 prior to pregnancy until D19 after pregnancy. All animals were sacrificed on D 20 of pregnancy by caesarean section. The numbers of survival, dead and absorbed fetuses were calculated and the survival fetus weight was measured. The survival fetuses were treated by two methods: One third survival fetuses were fixed and stained by Bouin solution for organ examination and the remaining two thirds fetuses were stained for skeleton examination.

RESULTNo obvious embryo toxicity was observed in the first experiment at Cinnabaris dose levels of 0.08, 0.4, or 4 g x kg(-1) x d(-1). There was no significant effect on embryonic development and the numbers of the survival, dead and absorbed fetus. No obvious malformations on appearance, organ, and skeleton examination of fetuses were found. The second experiment showed that the rates of abortion and absorbed fetus in 0.4, 4 g x kg(-1) x d(-1) Cinnabaris group were higher but without statistical significance compared with control group. Appearance and organ examination of Cinnabaris groups fetus showed no obvious malformation, but skeleton malformation was found in 0.4, 4 g x kg(-1) x d(-1) groups (the rates of skeleton malformation were 46.7% and 77.8%, respectively).

CONCLUSIONNo obvious embryonic development toxicity was observed when Cinnabaris was orally given in intermediate and late pregnant period, but the embryos in the early stage of pregnancy was more sensitive to Cinnabaris. When Cinnabaris was given prior to pregnancy until the whole period of pregnancy, it may be harmful for the fetuses at above the dose level 0.08 g x kg(-1) x d(-1) (equivalent to 5 times clinical intake dose), both in a dose-dependent manner.