The termination of early pregnancy in the mouse by beta-momorcharin.

beta- Momorcharin is a basic glycoprotein found in the seeds of Momordica charantia L. It differed immunologically from alpha- momorcharin also of the same source but possessed similar mid-term abortifacient activity. Intraperitoneal administration of beta- momocharin into mice on Days 4 and 6 of pregnancy led to an inhibition of pregnancy. In vitro study showed that the protein disturbed peri-implantation development by: (a) blocking the hatching of embryos from the zona pellucida; (b) decreasing the incidence of successful attachment of the blastocyst; (c) reducing the trophoblast outgrowth; and (d) disrupting the development of inner cell mass. It is likely that beta- momorcharin inhibited embryonic implantation by a similar biological action previously described for alpha- momorcharin .