Abstract
The total benzene extract of Hibiscus rosa sinensis (China rose plant) flowers showed potent, orally effective antifertility activity in albino rats when administered from day 1 to 10 of pregnancy. This activity of the extract was found to depend upon the dose and duration of treatment. The extract was not found to affect the tubual transport of the zygote as well as blastocyst per se from implanting. However, as studied by pontamine blue reaction and administration of extract during implantation, it seems that, at least in 70 % of the females, the antifertility activity of the drug was mediated via interruption in implantation. The results obtained by delayed implantation technique further suggest that the extract, in one way or other, alters the delicate estrogen-progesterone balance. The pregnancy maintenance by higher dose of oestrone in extract treated females further lend support to the curtailment of estrogen. However, invoking „anti-implantation factor” alone, is not responsible enough to achieve full contraception and the drug causes obsorption of foetus.
