Eighty percent of men over 80 suffer from symptoms of Benign Prostate Hyperplasia (BPH).(1) The use of Complementary and Alternative Medicine has a long history in the case of BPH, especially in European countries.(2)
To study the effect of pumpkin seed oil on prostate hyperplasia induced by subcutaneous injection of testosterone in rat (3mg per 100g body weight for 20 days), concurrently, either pumpkin seed oil (2 and 4mg per 100g body weight) or corn oil (as carrier) was orally administered for 20 days. Each week, the rats were weighed and the effect of testosterone and pumpkin seed oil was studied on weight gain of the rats. On the 21st day the rats were sacrificed and their prostates removed, cleaned and weighed. Then, the ratio of the prostate weight (to body weight of the rat) was calculated. Neither testosterone nor pumpkin seed oil had a significant effect on weight gain in the rats. Testosterone considerably increased prostate size (p<0.05), and this increase was inhibited in rats which had received 2mg per 100g body weight of pumpkin seed oil. The protective effect of pumpkin seed oil was considerable with the higher dose (p<0.02). The researchers concluded that pumpkin seed oil inhibits prostate hyperplasia induced by testosterone, and therefore, might be useful in the management of BPH.
Testosterone is converted to dihydrotestosterone in the prostate by 5-alpha-reductase, which is a stronger hydrogenic hormone and causes growth in the prostate. The inhibition of synthesis or function of dihydrotestosterone can inhibit prostate growth. Research has shown that the effect of pumpkin seed oil might be dependent on the phytosterol compounds which interfere with dihydrotestosterone. Therefore, the efficacy of pumpkin seed oil in BPH might be due to direct effect on the size of the prostate and consequently, urologic function.(1)
In a randomized, placebo-controlled, double blind clinical trial, 74 patients with BPH, with the International Prostate Symptom Score (IPSS) of more than 8, received for 12 months sweet potato starch (group A, placebo, 320mg per day), pumpkin seed oil (group B, 320mg per day), saw palmetto oil (group C, 320mg per day), or pumpkin seed oil together with saw palmetto oil (group D, 320mg each per day). IPSS, quality of life, plasma prostate-specific antigen, prostate size and the maximum urine flow was measured. In groups B, C and D the IPSS decreased after 3 months. In comparison with the base measures, the score for quality of life improved after 6 months in group D, but after 3 months in groups B and C. Serum prostate-specific antigen decreased after 3 months only in group D, but regarding prostate size, no significant difference was observed in the test groups. The maximum urine flow significantly improved in group B after 6 months, and in group C after 12 months. None of the parameters decreased significantly with the combination of pumpkin seed oil and saw palmetto oil. Based on these results, the prescription of pumpkin seed oil and saw palmetto oil is clinically safe and is effective as a CAM drug for BPH.(2)
In western countries, the use of pumpkin seed oil (pepo species) has shown some benefits for the treatment of nocturnal enuresis in patients with urological disorders. Also, a study has shown that seed oil of maxima species of pumpkin also, like pepo species, is effective in treating urological disorders in human, like Overactive Bladder (OAB).(3) In drug management of this condition, in addition to alpha-blockers and 5-alpha-reductase inhibitors, dietary interventions are also used, including the use of pumpkin seed oil.(1,2) Pumpkin seed is a rich source of vitamins A, B and E, linoleic acid, oleic acid, zinc, selenium, carbohydrates and phytosterols.