Scientific Studies of Pumpkin Seeds and Pumpkin Seed Oil


Journal of Medicinal Food

Inhibition of Testosterone-Induced Hyperplasia of the Prostate of Sprague-Dawley Rats by Pumpkin Seed Oil

Jun 2006, Vol. 9, No. 2 : 284 -286 M.€Gossell-Williams Pharmacology Section, Department of Basic Medical Sciences, University of the West Indies, Jamaica. A.€Davis Pharmacology Section, Department of Basic Medical Sciences, University of the West Indies, Jamaica. N.€O'Connor Pharmacology Section, Department of Basic Medical Sciences, University of the West Indies, Jamaica.

The oil from the pumpkin (Cucurbita pepo) seed is claimed to be useful in the management of benign prostatic hyperplasia. This investigation seeks to examine the effect of pumpkin seed oil on testosterone-induced hyperplasia of the prostate of rats.

Hyperplasia was induced by subcutaneous administration of testosterone (0.3 mg/100 g of body weight) for 20 days. Simultaneous oral administration of either pumpkin seed oil (2.0 and 4.0 mg/100 g of body weight) or corn oil (vehicle) was also given for 20 days. The weights of the rats were recorded weekly, and the influence of testosterone and pumpkin seed oil on the weight gain of the rats was examined. On day 21, rats were sacrificed, and the prostate was removed, cleaned, and weighed. The prostate size ratio (prostate weight/rat body weight) was then calculated.

Neither testosterone nor pumpkin seed oil had any significant influence on the weight gain of the rats. Testosterone significantly increased prostate size ratio (P < .05), and this induced increase was inhibited in rats fed with pumpkin seed oil at 2.0 mg/100 g of body weight. The protective effect of pumpkin seed oil was significant at the higher pumpkin seed oil dose (P < .02).

We conclude pumpkin seed oil can inhibit testosterone-induced hyperplasia of the prostate and therefore may be beneficial in the management of benign prostatic hyperplasia.

Antioxidative effects of pumpkin seed (Cucurbita pepo) protein isolate in CCl4-Induced liver injury in low-protein fed rats

C. Z. Nkosi 1, A. R. Opoku 1, S. E. Terblanche 2 *

1 Department of Biochemistry and Microbiology, University of Zululand, Private Bag X1001, KwaDlangezwa, 3886, South Africa
2 Department of Biochemistry and Microbiology, University of Zululand, P. O. Box 25542, Langenhovenpark, 9330, South Africa
email: S. E. Terblanche (

Correspondence to S. E. Terblanche, Department of Biochemistry and Microbiology, University of Zululand, P. O. Box 25542, Langenhovenpark 9330, South Africa.
Funded by:

  • Research Committee of the University of Zululand
  • Medical Research Council of South Africa
  • South African Sugar Association
  • pumpkin seed protein isolate, Cucurbita pepo, carbon tetrachloride-induced liver injury, low-protein fed rats, plasma enzymes, total antioxidant capacity, lipid peroxidation


The effects of pumpkin seed (Cucurbita pepo) protein isolate on the plasma activity levels of catalase (CA), superoxide dismutase (SOD), glutathione peroxidase (GSHpx) and total antioxidant capacity (TAC) as well as glucose-6-phosphatase (G6Pase) in liver homogenates and lipid peroxidation (LPO-malondialdehyde-MDA) levels in liver homogenates and liver microsomal fractions against carbon tetrachloride (CCl4)-induced acute liver injury in low-protein fed Sprague-Dawley rats (Rattus norvegicus) were investigated.

A group of male Sprague-Dawley rats maintained on a low-protein diet for 5 days were divided into three subgroups. Two subgroups were injected with carbon tetrachloride and the other group with an equivalent amount of olive oil. Two hours after CCl4 intoxication one of the two subgroups was administered with pumpkin seed protein isolate and thereafter switched onto a 20% pumpkin seed protein isolate diet. The other two groups of rats were maintained on the low-protein diet for the duration of the investigation. Groups of rats from the different subgroups were killed at 24, 48 and 72 h after their respective treatments. After 5 days on the low-protein diet the activity levels of all the enzymes as well as antioxidant levels were significantly lower than their counterparts on a normal balanced diet. However, a low-protein diet resulted in significantly increased levels of lipid peroxidation. The CCl4 intoxicated rats responded in a similar way, regarding all the variables investigated, to their counterparts on a low-protein diet.

The administration of pumpkin seed protein isolate after CCl4 intoxication resulted in significantly increased levels of all the variables investigated, with the exception of the lipid peroxidation levels which were significantly decreased. From the results of the present study it is concluded that pumpkin seed protein isolate administration was effective in alleviating the detrimental effects associated with protein malnutrition and CCl4 intoxication.

It is therefore apparent that pumpkin seed protein isolate has components that have antiperoxidative properties.

Pharmacological Research

Fahim AT Abd-el Fattah AA Agha AM Gad MZ
Effect of pumpkin-seed oil on the level of free radical scavengers induced during adjuvant-arthritis in rats.
In: Pharmacol Res (1995 Jan) 31(1):73-9 ISSN: 1043-6618

Pumpkin-seed oil (PSO), a natural supplement rich with antioxidant ingredients, was given to rats in which arthritis was induced using Freund's complete adjuvant. Its effect was compared with that of indomethacin, as a classical anti-inflammatory agent. Two experimental patterns were studied, an acute phase that was applied only with pumpkin seed oil and a chronic phase applied for both pumpkin seed oil and indomethacin.

Compared to normal untreated rats, it was shown that the induction of arthritis caused a decrease in serum sulphhydryl groups, with an increase in serum ceruloplasmin in both phases. Blood glutathione was first elevated in the acute phase, then its level was reduced in the chronic phase. Serum N-acetyl-beta-D-glucosaminidase activity was elevated only at the acute phase, while plasma total proteins and albumin were reduced at the chronic phase. Liver glucose- 6-phosphate dehydrogenase activity was markedly increased, while no changes were observed in the levels of liver lipid peroxides and glutathione. These changes in the studied parameters were attributed to the superoxides and free radicals during arthritic inflammation.

Administration of pumpkin seed oil succeeded in modulating most of the altered parameters affected during arthritis, especially at the chronic phase. Also, a remarkable inhibition of paw oedema was observed. A similar pattern was obtained upon treatment with indomethacin except that indomethacin markedly elevated liver lipid peroxides levels. Concurrent administration of pumpkin seed oilwith indomethacin caused no changes in the parameters studied compared to that induced by treatment with indomethacin alone. Registry Numbers: 53-86-1 (Indomethacin) 70-18-8 (Glutathione

American Journal of Clinical Nutrition

Suphakarn VS Yarnnon C Ngunboonsri P

The effect of pumpkin seeds on oxalcrystalluria and urinary compositions of children in hyperendemic area.

In: Am J Clin Nutr (1987 Jan) 45(1):115-21 ISSN: 0002-9165

We investigated the effect of pumpkin-seed supplementation on oxalcrystalluria and urinary composition in 20 boys age 2-7 yr from a hyperendemic area of Ubol province in Thailand. The experiment had four periods: control (before treatment), oxalate supplementation 5mg X kg-1 body wt X day-1, pumpkin-seed or orthophosphate supplementation 60 mg X kg body wt-1 X day-1, and posttreatment. Causal morning and 24-h urines were collected analyzed for crystalluria, pH, calcium, phosphorous, oxalate, creatinine, sodium, potassium, citrate glycosaminoglycans, and pyrophosphate.

The results demonstrated that the longer the supplementation period of pumpkin seeds, the better were the results. Pumpkin seeds lowered calcium- oxalate crystal occurrence and calcium level but increased phosphorus, pyrophosphate, glycosaminoglycans, and potassium values in urine as compared with orthophosphate supplementation. Pumpkin seeds provide high phosphorus levels and can be used as a potential agent in lowering the risk of bladder-stone disease.

ACTA Pharmaceutica Hungarica

Matus Z Molnar P Szabo LG [Main carotenoids in pressed seeds (Cucurbitae semen) of oil pumpkin (Cucurbita pepo convar. pepo var. styriaca)]

Olajtok (Cucurbita pepo convar. pepo var. styriaca) magjabol nyert presmaradek ossz-karotinoid-tartalmanak es karotinoid-osszetetelenek meghatarozasa. In: Acta Pharm Hung (1993 Sep) 63(5):247-56 ISSN: 0001-6659 (Published in Hungarian)

Various use of the oil-pumpkin offers reason for the phytochemical analysis of seed-meal's carotene pigments. Column chromatography was performed on the adsorbents MgO, Celite and CaCO3 with hexane and benzene as eluents. HPLC separation of different pigments was carried out on a 6 microns reverse phase packing with a ternary gradient elution method using a diode-array detector.

The main components of the press-residue were lutein [3,3'-dihydroxy-alpha-carotene = (3R,3'R,6'R)-beta,epsilon-carotene-3,3'-diol; 52.5%] and beta- carotene (beta,epsilon-carotene; 10.1%). In addition to the above- mentioned pigments it was successful to reveal the presence of violaxanthin, luteoxanthin, auroxanthin epimers, lutein epoxide, flavoxanthin, chrysanthemaxanthin, 9(9')-cis-lutein, 13(13')-cis- lutein, 15-cis-lutein (central-cis)-lutein, alpha-cryptoxanthin, beta- cryptoxanthin and alpha-carotene (beta,epsilon-carotene) in small quantities

The Source: