Activity of alkaloid extract of caricapryl–99 seeds (
Carica papaya
Linn seeds) on the serum levels of steroid hormones was studied in adult male albino rats. Three tolerated doses obtained from the graph of percectage toxicity (10, 50 and 150 mg/kg) were separately administered orally, daily for three days to three groups of male rats (n=5) while group four of 5 rats received the vehicle (corn oil) as control. The results showed that 10mg/kg/d caused increase serum levels of FSH and estrogen but decrease in the serum levels of LH and testosterone compared to control; 50mg/kg/d elevated the serum levels of FSH, estrogen but inhibited testosterone; while 150mg/kg/d pretreatments caused a significant decrease (p<0.01) in the serum levels of FSH, LH and testosterone. The results permitted the conclusion that caricapryl-99 treatment inhibited the serum level of the androgen, testosterone which might result in a male infertility.