Advertisement

Studies on the post-coital contraceptive mechanisms of crude extract of Sri Lankan marine red algae, Gelidiella acerosa

      This paper is only available as a PDF. To read, Please Download here.

      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.

      Keywords

      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'

      Subscribe:

      Subscribe to Contraception
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect

      References

        • Ratnasooriya WD
        • Premakumara GAS
        • Tillekeratne LMV
        Post-coital contraceptive activity of crude extracts of Sri Lankan marine red algae.
        Contraception. 1994; 50: 291-299
        • Edgren RA
        • Calhoun DW
        The biology of steroidal contraceptives.
        in: Edgren RA The chemical control of fertility. Marcel Dekker, New York1957: 537
        • Ulmann A
        • Dubois C
        • Philibert P
        Fertility control with RU486.
        Hormone Res. 1987; 28: 274-278
        • Farnsworth NR
        • Bingel SA
        • Soejarto DD
        Potential value of plants as a source of antifertility agents-II.
        J Pharm Sci. 1976; 64: 535-593
        • Gidley-Baird AA
        • O'Neill C
        • Sinosich MJ
        • Porter RN
        • Pike IL
        • Saunders DM
        Failure of implantation in human in vitro fertilization and embryo transfer patients: the effects of altered progesterone estrogen ratios in human and mice.
        Fertil Steril. 1986; 45: 69-74
        • Arkaravichien W
        • Kendle KE
        Fetal viability and fetal growth after prolonged uterine contractions induced by progesterone withdrawal in late pregnancy in rats.
        J Reprod Fert. 1992; 96: 299-308
        • Van Look PFA
        • Hertzen von H
        Emergency contraception.
        Br Med Bull. 1993; 49: 158-170
        • Bonney RC
        • Franks S
        The endocrinology of implantation and early pregnancy.
        Bailliere's Clin Endocrinol Met. 1990; 4: 207-231
        • O'Neill C
        Embryo-derived platelet activating factor.
        Reprod Fertil Dev. 1992; 4: 283-288
        • Phillips CA
        • Poyser NL
        Prostaglandins and implantation in the rat.
        in: Advances in Prostaglandin and Thromboxane Research. vol 8. Raven Press, New York1980: 1391-1393
        • Ray S
        • Sharma L
        Development of progesterone antagonists and fertility regulating agents.
        Pharmazie. 1987; 42: 656-661
        • MacNieven E
        • DeCatanzaro D
        Reversal of stress-induced pregnancy blocks in mice by progesterone and metyrapone.
        Physiol Behav. 1990; 47: 443-448
        • Heap RB
        Paracrine and autocrine functions of the placenta: a key to the success of viviparity.
        Exp Clin Endocrinol. 1994; 102: 262-268
        • Kennedy JF
        • White CA
        Bioactive Carbohydrates Chemistry, Biochemistry and Biology. Ellis (Horwood), 1983
        • Gendron RL
        • Nestel FP
        • Lapp WS
        • Baines MG
        Lipopolysaccharide-induced fetal resorption in mice is associated with the intrauterine production of tumour necrosis factor-alpha.
        J Reprod Fert. 1990; 90: 395-402