En 1680-6433 2008-2177 Effect of Cnidoscolous aconitifolius (Miller) I.M. Johnston leaf extract on reproductive hormones of female rats Background: The increase in the rate of infertility in women has prompted the need to search for plants with antifertility potentials. Objective: The effect of administration of aqueous extract of Cnidoscolous aconitifolius leaves for seven days on reproductive hormones of female Wistar rats was investigated. Materials and Methods: Sixty female albino rats were grouped into four (A, B, C and D) of 15 each. Group A (the control) received orally 6.5 ml kg-1 body weight of distilled water on daily basis for 7 days. Groups B, C and D were treated like the control except that they received 250, 500 and 1000 mg kg-1 body weight of the extract. Results: Phytochemical screening of the extract revealed the presence of alkaloids, saponins, phenolics, tannins, flavonoids, anthraquinones, phlobatannins and triterpenes. Administration of the extract produced significant increase (p<0.05) in the serum prolactin concentration whereas those of estradiol, progesterone, follicle stimulating and luteinizing hormones were significantly reduced. Conclusion: The alterations in the female rat reproductive hormones by the extract are indications of adverse effect on the maturation and ovulation of follicles. Consequently, the extract may impair fertility and conception in female rats. Thus, the Cnidoscolous aconitifolius leaf extract may be explored as a female contraceptive. Background: The increase in the rate of infertility in women has prompted the need to search for plants with antifertility potentials. Objective: The effect of administration of aqueous extract of Cnidoscolous aconitifolius leaves for seven days on reproductive hormones of female Wistar rats was investigated. Materials and Methods: Sixty female albino rats were grouped into four (A, B, C and D) of 15 each. Group A (the control) received orally 6.5 ml kg-1 body weight of distilled water on daily basis for 7 days. Groups B, C and D were treated like the control except that they received 250, 500 and 1000 mg kg-1 body weight of the extract. Results: Phytochemical screening of the extract revealed the presence of alkaloids, saponins, phenolics, tannins, flavonoids, anthraquinones, phlobatannins and triterpenes. Administration of the extract produced significant increase (p<0.05) in the serum prolactin concentration whereas those of estradiol, progesterone, follicle stimulating and luteinizing hormones were significantly reduced. Conclusion: The alterations in the female rat reproductive hormones by the extract are indications of adverse effect on the maturation and ovulation of follicles. Consequently, the extract may impair fertility and conception in female rats. Thus, the Cnidoscolous aconitifolius leaf extract may be explored as a female contraceptive. Cnidoscolous aconitifolius, Prolactin, Follicle stimulating hormone, Luteinizing hormone, Estradiol, Progesterone, Fertility, Conception, Contraceptive. Cnidoscolous aconitifolius, Prolactin, Follicle stimulating hormone, Luteinizing hormone, Estradiol, Progesterone, Fertility, Conception, Contraceptive. 149 155 Musa Toyin Yakubu tomuyak@yahoo.com, tomuyak@gmail.com No