Effect Of Garcinia Kola Seed Alkaloid Extract On Levels Of Gonadal Hormones And Pitutary Gonadotrophins In Rat Serum

Abstract

The effects of three tolerated oral doses (350 mg/kg, 1500 mg/kg, 2000 mg/kg) of methanolic alkaloid extract of Garcinia kola seed (GKA) on serum levels of estradiol, progesterone, prolactin, FSH and LH were observed in female rats (125-170 g). The control animals received 2ml oral doses of methanolic saline (0.9% NaCl) daily and the treatment period of dosing for all animals lasted 3, 7 or 30 days, at the end of which they were exsanguinated to collect serum for hormonal assays. In another study, the effects of daily oral doses of GKA (350 mg/kg or 2000 mg/kg for days; 300 mg/kg, 1300 mg/kg or 2000 mg/kg for days; 1500 mg/kg for 14 days) on serum levels of testosterone, LH and FSH were observed in male rats (150 – 175). The experiments showed that serum LH, FSH and prolactin levels were lower, while estradiol and progesterone levels were higher, than control values in females. There was marked reduction in serum testosterone and a concomitant elevation of serum FSH and LH in males. The findings suggest a possible antifertility consequence of treatment with GKA.

Key words: Garcinia kola seeds; alkaloids; gonadotrophins; sex hormones.

Nigerian Journal of Physiological Sciences Vol.18(1-2) 2003: 59-64