Background & Objectives : Considering the widespread use of walnut in the cooking of foods and medical applications, the present study evaluate possible effects of alcoholic extract of Walnut on FSH, LH and testosterone concentration in adult male rats.

  Methods: In this experimental study 40 adult male Wistar rats weighing 250-300g were used and divided into five groups, eight rats per each group. Control group do not receive any treatment . Organic solvent was administered as placebo to sham group , three experimental group, that receive different doses of alcoholic extract of walnut , 10 - 20 and 50 (mg/ kg/Intraperitoneally) respectively, were fed daily and serum levels of FSH, LH and testosterone were measured. All data were analyzed by SPSS 16 and one way ANOVA test.
Results: In comparison with control group, only in group treated by 50 mg/kg of walnut extract, FSH and LH concentration increased significantly (P<0.05). Concentration of testosterone in experimental groups (20 mg/kg and 50mg/kg dose of extract) showed significant statistical difference compared with other groups (P<0.05) .

  Conclusion: According to results of this study, alcoholic extract of Walnut affect pituitary- testis axis and increase GnRH and LH secretion rate therefore enhance reproductive activity in male rats.