title: Studies on the post-coital contraceptive mechanisms of crude extract of Sri Lankan marine red algae, Gelidiella acerosa.
abstract: This study investigates the potential post-coital contraceptive mechanisms of the crude extract of Sri Lankan marine red algae, Gelidiella acerosa, using rats. The dose used was 1000 mg/kg/day and the route of administration was oral. The results showed that the crude extract possessed potent post-coital contraceptive activity when administered on days 7-8 of pregnancy indicating the presence of a narrow window in its action. The post-coital contraceptive activity was due to an elevated post-implantation loss (by 89%) resulting from fetal death between days 9-14 of pregnancy. The extract was neither estrogenic nor anti-estrogenic nor stressor but appeared to be anti-progestational (reduced ovarian progesterone output). It is suggested that the crude extract may reduce the ovarian progesterone release possibly via anti-platelet and PGE2-depressing activity.
authors.affiliation: Department of Zoology, University of Colombo, Sri Lanka.
authors.forename: G A
authors.initials: GA
authors.lastname: Premakumara
authors.forename: W D
authors.initials: WD
authors.lastname: Ratnasooriya
authors.forename: L M
authors.initials: LM
authors.lastname: Tillekeratne
mesh_terms: D000818:Animals; D003281:Contraceptives, Postcoital / Q000008:administration & dosage; D047108:Embryonic Development; D004965:Estrogen Antagonists; D005260:Female; D005327:Fetal Resorption / Q000139:chemically induced; D006727:Hormone Antagonists; D008297:Male; D011247:Pregnancy; D011374:Progesterone / Q000037:antagonists & inhibitors; D051381:Rats; D000461:Rhodophyta / Q000737:chemistry*; D013997:Time Factors
chemical_list: D003281:Contraceptives, Postcoital; D004965:Estrogen Antagonists; D006727:Hormone Antagonists; D011374:Progesterone