Cucurbita

Cucurbita (Pumpkin / Squash): A Comprehensive Reference

1. Identity and Botanical Classification

Cucurbita is a genus of flowering plants in the family Cucurbitaceae, commonly known as pumpkins, squashes, and gourds. Three species are of primary relevance in phytomedicine and dietary supplementation: Cucurbita maxima Duchesne, Cucurbita pepo L., and Cucurbita moschata Duchesne. Cucurbita pepo L. is a herbaceous, monoecious, annual plant of the Cucurbitaceae family. The genus contains multiple additional cultivated species, including C. argyrosperma and C. ficifolia, all native to the Americas.

C. pepo pumpkins are among the oldest known domesticated plants, with evidence of their cultivation dating to between 7000 BCE and 5500 BCE in Mesoamerica. Wild species and the earliest domesticated forms are native to North America, specifically parts of present-day northeastern Mexico and the southern United States, but cultivars are now grown globally.

The part of the plant most frequently used as a dietary supplement is the seed (Cucurbitae semen) and the oil cold-pressed from those seeds. The herbal substance — the whole, dried, ripe seed — is mentioned in several well-known pharmacopeial handbooks, including those of Madaus (1938), Bradley (2006), Martindale (2007), and Wichtl (2004), as well as in the German Commission E Monograph (1991), WHO Monographs (2009), and ESCOP Monographs (2009).

1.1 Common Names and Preparations

Depending on species and region, plants of this genus are called pumpkin, squash, gourd, calabaza, zucchini, marrow, and various vernacular names. In herbal medicine and as dietary supplements, Cucurbita is primarily encountered in the following forms:

• Whole ground seed: dried, ripe seeds ground for direct oral intake or inclusion in foods.
• Cold-pressed seed oil (pumpkin seed oil / PSO): a dark green oil that contains a high amount of free fatty acids.
• Ethanolic or hydroethanolic soft extract (PSE): standardised extracts used in clinical trials and registered traditional herbal medicines.
• Oil-free hydroethanolic extract: a preparation whose therapeutic potential has been highlighted in recent studies, though its composition remains insufficiently characterized considering the species' significant phenotypic and phytochemical variability.
• Capsules and tablets: the most common pharmaceutical form, containing standardised seed oil or dry extract.

Several cultivars display metabolite profiles comparable to the Cucurbita pepo var. styriaca variety (Styrian pumpkin) currently recommended by the European Pharmacopoeia (Ph. Eur.) and the Committee on Herbal Medicinal Products (HMPC). The hull-less Styrian pumpkin is particularly important in commercial extract production because its seeds can be processed without dehulling.

2. Historical and Traditional Use

2.1 Pre-Columbian Americas

Seeds and remnants of Cucurbita have been found in various archaeological sites across the Americas dating back to approximately 10,000 years ago, and these findings suggest that pumpkins were widely cultivated by indigenous peoples long before European contact. Direct radiocarbon dating indicates that humans started using wild Cucurbita starting approximately 10,950 calendar years before present, primarily as watertight vessels and possibly as cooking and drinking containers.

Indigenous peoples of the Americas, including the Maya, Aztec, and various Native American tribes, have long histories of cultivating and utilizing pumpkins. By the time of European contact in 1492, several cultivar groups of pumpkins and squashes had already been developed by indigenous American peoples. One notable historical document is the Florentine Codex, compiled in the 16th century by the Spanish friar Bernardino de Sahagún, which provides detailed descriptions of Aztec agriculture including the cultivation and uses of pumpkins.

For Native Americans, pumpkins were not only a source of nourishment but also used for healing; the Mayans, for example, used the juice in salves for burns. Pumpkin (Cucurbita pepo) seeds were used locally in Eritrea to treat tapeworm, illustrating how anthelmintic use of the seeds has persisted across geographically disparate cultures.

2.2 European and Asian Traditional Use

The seeds and oil from pumpkin seeds have been used for many years for the relief of difficulties associated with an enlarged prostate gland and micturition problems related to overactive bladder. Cucurbita is a globally well-known and old-fashioned herbal medicinal product that has been used over the past several centuries, with its medicinal and therapeutic use described in many textbooks and traditional medicinal manuscripts. In Europe, C. pepo in the form of ethanolic pumpkin seed soft extract has been widely used and has been primarily registered as a remedy for urological conditions, specifically those related to an enlarged prostate gland and micturition problems related to an overactive bladder.

In many countries, pumpkin is used as a medicine for its anti-inflammatory, antioxidant, antiviral, and antidiabetic properties, particularly in Austria, Hungary, Mexico, Slovenia, China, Spain, and various European, Asian, and African countries. Cucurbita spp. have been traditionally employed to address a range of ailments such as cardiovascular disease, atherosclerosis, diabetes, muscle pain, and inflammation, in addition to their use in food and as dyes.

C. maxima is traditionally used in Mexico, China, and India for its hypoglycemic effect helpful in controlling blood glucose. Pumpkin seeds have been known in folk medicine as a remedy for kidney, bladder, and prostate disorders since centuries.

2.3 Regulatory Recognition of Traditional Use

In 2013, the Committee on Herbal Medicinal Products (HMPC) published a monograph recognizing the traditional use of C. pepo seeds for the relief of lower urinary tract symptoms associated with BPH or overactive bladder (OAB), based on long-standing medicinal use.

3. Phytochemistry: Key Constituents and Active Compounds

The fruit of pumpkin including the flesh, seed, and peel are a rich source of primary and secondary metabolites, including proteins, carbohydrates, monounsaturated fatty acids, polyunsaturated fatty acids, carotenoids, tocopherols, tryptophan, delta-7-sterols, and many other phytochemicals.

3.1 Lipids and Fatty Acids

Seeds have been found to be rich in oil (approximately 35%), protein (38%), alpha-tocopherols (3 mg/100 g) and carbohydrate content (approximately 37%). The four dominant fatty acids are palmitic C16:0 (13.3%), stearic C18:0 (8.0%), oleic C18:1 (29.0%), and linoleic C18:2 (47.0%); the oil contains an appreciable amount of unsaturated fatty acids (78.0%) and is a rich source of linoleic acid (47.0%). In the seed oil, unsaturated acids are dominant (oleic and linoleic), and their proportion depends on the pumpkin variety.

3.2 Phytosterols — Especially Δ7-Sterols

Linoleic acid, oleic acid, palmitic acid, ECN-44, ECN-46, tocopherols, β-sitosterol, and delta-7-sterols constitute a large quantity of pumpkin seed oil. The active components of C. pepo L. seeds are D5-, D7-, and D8-sterols; D7-sterols are found in a predominant proportion in C. pepo and are significantly registered as vital active components for the treatment of mild prostatic hyperplasia. These sterols have not been found in any other sterol-containing plant extracts used in the treatment of BPH. Delta-7-spinasterol and Δ7-stigmasterol together represent major fractions of total sterol content, with Δ7-stigmasterol at 12.5–20.3 g/100 g and Δ7,25-stigmastadienol at 5.8–8.0 g/100 g of total sterol content.

3.3 Tocopherols and Carotenoids

Pumpkin seed oil is rich in biologically active substances including tocopherols and carotenoids, especially β-carotene and lutein. Cucurbits display antioxidant effects thanks to their various bioactive compounds with free radical scavenging ability, such as cucurbitacins B and E, ellagitannins, or carotenoids such as α-carotene, β-carotene, lutein, and zeaxanthin. Carotenoids are needed for proper vision and are also metabolized to form vitamin A, which helps to improve bodily function and immunity.

3.4 Cucurbitacins

Cucurbitacins are found in many cucurbitaceous plants and are most common in species of the genera Bryonia, Cucumis, Cucurbita, Luffa, Echinocystis, Lagenaria, and Citrullus. The level of cucurbitacins varies between tissues; they may be concentrated in fruits and roots of mature plants, with highest concentration achieved on maturity in fruits where they are produced. Seeds generally contain very low concentrations of cucurbitacins. Apart from their toxic nature, cucurbitacins have been shown to possess pharmacological effectiveness against inflammation, cancer, atherosclerosis, and diabetes.

3.5 Proteins, Amino Acids, and Tryptophan

Pumpkin seeds provide high-quality proteins, unsaturated fatty acids, and minerals such as magnesium, zinc, iron, and potassium, supporting cardiovascular health, immune function, and gastrointestinal well-being. They also contain phytosterols, antioxidants (vitamin E, carotenoids), cucurbitacins, lignans, and tryptophan, which have been associated with cholesterol reduction, oxidative stress mitigation, anti-inflammatory effects, hormonal regulation, and neurochemical benefits in preclinical studies.

3.6 Polyphenols and Flavonoids

Despite the ubiquitous presence of phenolic acids in plant-based foods and their role as dietary antioxidants, the literature about phenolic compounds in C. pepo was limited until recently. They represent approximately 30% of polyphenols taken by diet and have antioxidant capacity related to their health-promoting features; a certain profile of phenolic acids is also present in pumpkin seed and may contribute to prevention or treatment of different disorders in humans. The flavonoid content in fresh pumpkin is 45 mg QE/100 g in the peel, 77.1 mg QE/100 g in the flesh, and 139 mg QE/100 g in the seeds.

3.7 Polysaccharides

The fruits of C. moschata are also rich in polysaccharides that show strong hypoglycemic and antidiabetic effects in preclinical studies. Protein-bound polysaccharides have been reported to lower blood glucose level, increase plasma insulin level, and increase glucose tolerance in alloxan-induced diabetic rats; this blood glucose-lowering effect of pumpkin polysaccharides may be due to the antioxidant nature of polysaccharides, which protects β-cells of the pancreas.

3.8 Squalene and Triterpenes

In seeds, the greatest concentrations of squalene were found, with a range of 583.2 to 747 mg/100 g. Several triterpenes, such as cucurbita-5,24-dienol, α- and β-amyrin, and sterols, are present in the seeds and flowers of Cucurbita maxima.

4. Mechanisms of Action

4.1 Inhibition of 5α-Reductase

A lipid-steroidal extract of pumpkin seed has been confirmed to have an inhibitory effect on 5α-reductase in cultured human prostate fibroblasts. The pharmacological mechanism of action of pumpkin seed oil is well-documented through inhibition of 5α-reductase, which is primarily responsible for the conversion of testosterone into dihydrotestosterone (DHT). Animal studies have demonstrated that after treatment with Cucurbita pepo seed extract, there is a significant reduction in pathological progression of hyperplastic prostates, including histological alterations and decreases in the levels of androgen receptor, 5α-reductase, and dihydrotestosterone.

4.2 MAPK Pathway and Apoptosis Regulation

Studies have isolated total phytosterols (TPSs) from hull-less pumpkin seed oil to investigate their therapeutic potential against BPH, observing histopathological changes of prostate in rat models and evaluating the molecular mechanisms behind these effects, including the mRNA and/or protein expression of 5α-reductase, androgen receptor, and the coactivator SRC-1 (steroid receptor coactivator 1).

4.3 Antioxidant and Anti-inflammatory Mechanisms

Pumpkin seed extract contributed to reductions in the levels of reactive oxygen species, oxidative stress, and inflammation in animal models. The extract also promoted enhancement of the transcription of nuclear factor erythroid 2-related factor (Nrf2), heme oxygenase-1 (Ho-1), and catalase (Cat), involved in antioxidant activity; endothelial nitric oxide synthase (eNos), involved in vasculoprotective activity; and Prdm16 and Pgc1α, involved in brown adipogenesis and thermogenesis.

4.4 Nitric Oxide Generation and Cardiovascular Effects

Authors demonstrated that both pumpkin seed oil and amlodipine treatments protected rats from L-NAME-induced defects in the heart and aorta through a mechanism that could involve the generation of nitric oxide, suggesting that pumpkin seed oil exhibits antihypertensive and cardioprotective effects.

4.5 Hypoglycemic Mechanisms

Pumpkin contains hypoglycemic agents, and it has active components like flavonoids, alkaloids, polysaccharides, and polyphenols that are beneficial in diabetes mellitus by protecting from oxidative stress damage or increasing sensitivity to insulin.

5. Scientific Evidence by Health Area

5.1 Benign Prostatic Hyperplasia (BPH) and Lower Urinary Tract Symptoms (LUTS)

This is the area with the most substantial body of clinical investigation for Cucurbita. The effect of pumpkin seed oil from C. pepo has been investigated in clinical trials involving over 2000 men suffering from benign prostate hypertrophy (BPH), and the oil significantly improved their urinary dysfunction.

GRANU Study (Vahlensieck et al., 2015)

The German Research Activities on Natural Urologicals (GRANU) study was a randomized, partially blinded, placebo-controlled, parallel-group trial that investigated the efficacy of pumpkin seed in men with lower urinary tract symptoms suggestive of BPH. A total of 1,431 men aged 50–80 years with BPH/LUTS were randomly assigned to pumpkin seed (5 g b.i.d.), capsules with pumpkin seed extract (500 mg b.i.d.), or matching placebo. The primary response criterion was a decrease in IPSS of ≥5 points from baseline after 12 months; secondary outcomes included IPSS-related quality of life, IPSS single items, and diary-recorded nocturia. After 12 months, the response rate (intention-to-treat/last-observation-carried-forward approach) did not differ between pumpkin seed extract and placebo. This is a major limitation of the clinical evidence base for pumpkin seed in BPH: the largest randomized controlled trial failed to demonstrate a statistically significant superiority over placebo on its primary endpoint.

24-Month Noninterventional Study (Theil et al., 2022)

In this study, the symptoms, quality of life, and sexual well-being of 130 patients with LUTS/BPH treated with pumpkin seed soft extract (PSE) were followed up for a maximum period of 2 years in a real-life setting. The cohort analyzed for the primary criterion consisted of 83 patients treated for at least 12 months. At 12 and 24 months, the IPSS was reduced by 4.7 and 5.1 points compared to baseline in 83 and 55 of the patients available for analysis, respectively. In men with moderate LUTS suggestive of BPH, a low progression risk, and an active sex life, treatment with pumpkin seed soft extract provided symptomatic relief, improved IPSS-QoL, and maintained sexual well-being. This study is observational and lacks a concurrent control arm, limiting the interpretation of its results.

Randomized Trial vs. Tamsulosin (Zerafatjou et al., 2021)

This single-blind randomized clinical trial included patients with BPH aged ≥50 years; patients were randomized into two groups: one received 0.4 mg tamsulosin every night at bedtime, and the other received 360 mg pumpkin seed oil twice a day. Pumpkin (Cucurbita pepo) seed oil relieved BPH symptoms with no side effects, but was not as effective as tamsulosin. Further studies are required to confirm the role of pumpkin seed oil as an option for the treatment of BPH symptoms.

Long-Term Korean Study (Hong et al., 2009)

Hong et al. (2009) carried out a long-term study of 12 months to evaluate the effectiveness and potential side effects of pumpkin seed oil and/or saw palmetto oil in Korean men with symptomatic BPH; treatment with 320 mg per day of pumpkin seed oil significantly reduced the IPSS when compared to the placebo group.

Meta-Analysis Context

The safety and efficacy of a well-tolerated proprietary pumpkin seed soft extract were investigated in two randomized placebo-controlled 12-month studies (the Bach and GRANU studies), both studying LUTS/BPH patients with an IPSS ≥13 points at baseline. The Bach study demonstrated positive effects of PSE compared to placebo, but no difference between treatments was observed in the GRANU study; a meta-analysis was conducted using patient-level data from these two studies. Overall, the evidence for Cucurbita in BPH is mixed. Individual positive findings exist, but the largest RCT did not meet its primary endpoint and the overall evidence is characterized as insufficient by systematic reviews. The oil extracted from pumpkin seed is used to treat the symptoms associated with BPH; however, human studies are few and available evidence is insufficient.

5.2 Overactive Bladder (OAB)

C. maxima Oil Study (45 subjects)

Forty-five subjects were enrolled in a study in which an extract of pumpkin seed oil from C. maxima (10 g of oil/day) was orally administered for 12 weeks. After 6 and 12 weeks, urinary function was evaluated using the Overactive Bladder Symptom Score (OABSS), and pumpkin seed oil from C. maxima significantly reduced the OABSS score in subjects. Notably, the trial reported no significant changes in lipid profiles or PSA levels during the intervention, underscoring its safety and efficacy; while not randomized or placebo-controlled, these findings suggest that PSO may have potential for managing OAB in both men and women.

Randomized Double-Blind Trial with Soy Germ Extract (Cucuflavone)

A randomized, double-blind, placebo-controlled study evaluated the efficacy and safety of Cucuflavone (containing extracts of pumpkin seed and soy germ) in 120 subjects suffering from OAB. After 12 weeks, subjects taking Cucuflavone experienced a significant reduction versus baseline in urination frequency, urgency, incontinence frequency, maximum urgency score, nocturnal urination frequency, and OAB-symptom scale, while the placebo group reached significant differences only for some of these endpoints. No adverse events or abnormal changes in safety parameters occurred. This trial cannot isolate the effect of pumpkin seed from that of the soy germ component.

A randomized, double-blind, placebo-controlled trial demonstrated that a formulation combining oil-free pumpkin seed extract with soy germ extract significantly reduced urinary frequency, urgency, and incontinence in women with OAB over 12 weeks. Another study showed that a similar product effectively improved symptoms of stress urinary incontinence in women over a six-week period. Additionally, a three-month pilot study found that oil-free pumpkin seed extract, used as a monotherapy, improved lower urinary tract symptoms in men with BPH without notable side effects.

5.3 Diabetes and Blood Glucose Regulation

Evidence for antidiabetic effects of Cucurbita species in humans is sparse; most data derive from preclinical models. In animal studies, diabetic rats fed diets supplemented with pumpkin flour had significantly lower blood sugar levels than those fed regular chow; the most pronounced effect was observed in rats fed soaked and fermented pumpkin flour, showing a 23.26% reduction in blood sugar. Researchers suggested that fiber, phenolic compounds, and carotenoids may be responsible for this effect. A previous investigation showed that pumpkin is reported to reduce blood glucose in type 2 diabetic patients, though large, well-controlled RCTs in humans are lacking. Pectin present in pumpkin, when consumed, controls glycemic levels and reduces the need for insulin in patients with diabetes, according to reported preclinical findings.

5.4 Cardiovascular and Antihypertensive Effects

One study demonstrated that oral administration of 500–1000 mg/day of C. pepo oil for 12 weeks decreased IPSS by 41.4%, and more than 96% of the patients had no undesired side effects, suggesting the extract is well-tolerated at these doses. The antihypertensive evidence in humans is limited; animal studies have demonstrated that pumpkin seed oil and amlodipine treatments protected rats from L-NAME-induced defects in the heart and aorta through a mechanism potentially involving nitric oxide generation, but this has not been replicated in adequately powered human RCTs.

5.5 Anthelmintic (Antiparasitic) Use

Pumpkin (Cucurbita pepo) seeds have been used locally in Eritrea to treat tapeworm. This traditional antiparasitic use is ethnographically documented but lacks modern randomized controlled clinical trial evidence.

5.6 Anticancer Activity

Medicinal derivatives of Cucurbita spp., such as hydroethanolic extracts, have demonstrated a wide spectrum of biological activities including anticancer, antimicrobial, and antiparasitic effects. However, while cucurbitacins have been extensively studied in vitro and in animal models, the transition to human studies adds another layer of complexity, and no definitive human clinical trials establish anticancer efficacy for Cucurbita preparations. This evidence remains in vitro and preclinical only.

5.7 Menopause-Related and Antioxidant Effects

In animal (ovariectomized rat) models, oral administration of pumpkin seed extract for 12 weeks decreased body weight, fat weight, and cardiac risk indices, and also contributed to reductions in the levels of reactive oxygen species, oxidative stress, and inflammation. These preclinical findings have not yet been confirmed by adequately powered human clinical trials in postmenopausal women.

6. Body Systems and Health Areas Associated with Cucurbita

• Urological system: BPH-related LUTS, overactive bladder, urinary frequency, urgency, nocturia, and incontinence — the best-documented area of clinical interest.
• Endocrine / metabolic: Blood glucose regulation, insulin sensitivity, and antidiabetic properties (primarily preclinical evidence).
• Cardiovascular: Antihypertensive, cardioprotective, and lipid-modulating effects (primarily preclinical and limited human data).
• Antioxidant / anti-inflammatory: Research has demonstrated anti-inflammatory, antibacterial, anticarcinogenic, antidiabetic, and antihypertensive properties associated with this plant.
• Gastrointestinal / antiparasitic: Traditional anthelmintic use; pectin-mediated effects on gut function.
• Oncology: Preclinical and in vitro anticancer activity through cucurbitacin-mediated mechanisms; no confirmed human evidence.
• Reproductive / hormonal: Benefits including improving spermatogenesis have also been reported by researchers.
• Dermatological / wound healing: Extracted oil from pumpkin seeds is an interesting target as it is composed with prominent pharmacological properties for possible wound healing treatments, based on animal models.

7. Dosage Forms and Dosages Reported in Studies

The following dosages are reported directly from clinical and institutional sources; they represent ranges used in studies or recognized by monographs, not prescriptive guidance.

• Whole ground seed (oral): Daily dose of 10–30 g of pumpkin seed, as ground seed or an equivalent amount of ethanolic extract, is referenced in the EMA assessment report.
• Seed oil capsules — BPH (GRANU study): 500 mg b.i.d. (twice daily) of pumpkin seed extract capsules, alongside 5 g b.i.d. whole seed arm.
• Seed oil capsules — BPH (Zerafatjou et al., 2021): 360 mg pumpkin seed oil twice a day (720 mg total daily) for 3 months.
• Seed oil capsules — BPH (Hong et al., 2009): 320 mg per day of pumpkin seed oil for 12 months.
• Seed oil — BPH (Friedrich/Vahlensieck referenced dosage): Vahlensieck et al. and Friedrich et al. used 1000 mg of pumpkin seed extract in their studies.
• Seed oil — IPSS reduction study: 500–1000 mg/day of C. pepo oil for 12 weeks.
• Seed oil — OAB (C. maxima): 10 g of oil/day orally administered for 12 weeks.
• Long-term use: According to the EMA assessment report, long-term use is possible (longer than 4 weeks).

8. Safety Considerations and Interactions

8.1 General Tolerability

Clinical trials report few adverse reactions. Methemoglobinemia caused by high nitrate content has been reported in infants given zucchini soup for constipation. IgE-related allergy to zucchini has been reported, as well as oral allergy syndrome, nausea, diarrhea, and pruritus. Cross-reactivity to watermelon, cucumber, and other Cucurbitaceae fruits has been demonstrated. There have been no reports of severe toxicity with the use of Cucurbita extracts.

8.2 Antinutrients

Antinutrients including oxalates, tannins, and cyanide have been described in the seeds and leaves. These are present at low levels in seeds used for supplementation and are not considered a significant concern at typical dietary and supplemental doses, but have been analytically identified.

8.3 Cucurbitacin Toxicity

Extensive evaluations of cucurbitacins C, D, E, and I have clearly classified them as lethal compounds. Consumption of plants containing these specific cucurbitacins, such as species of the genera Cucumis and Cucurbita, should be avoided at high levels to prevent illness or death. The manifestation of toxic symptoms varies depending on the animal species, route of administration, and dose. The determination of a safe dose of cucurbitacins remains elusive; their toxicity is highly dose-dependent, and even small amounts can have adverse effects, presenting a narrow therapeutic window. Crucially, as noted above, seeds generally contain very low concentrations of cucurbitacins, so this toxicity concern is more relevant to fruit-tissue or root extracts than to commercial seed preparations.

8.4 Drug Interactions

Warfarin (anticoagulants): Two cases of increased INR have been reported in patients taking a combination of pumpkin seed, saw palmetto, and vitamin E (Curbicin®). One of the patients had been stable on warfarin prior to starting the combination product. It is unclear whether the increased INR was due to the vitamin E content alone, pumpkin seed or saw palmetto alone, or a combination of all three ingredients. Caution is warranted when combining pumpkin seed preparations with anticoagulant therapy.

Antihypertensive and antidiabetic medications: Given the documented preclinical antihypertensive and hypoglycemic properties of pumpkin seed constituents, theoretical pharmacodynamic interactions with medications used for these conditions are plausible, though formal clinical interaction studies are not available in the published literature.

8.5 Allergy

Side effects from pumpkin products are rare, but might include stomach discomfort, diarrhea, and nausea. Pumpkin preparations might also cause itching, rash, and allergic reactions in some people. IgE-mediated hypersensitivity and cross-reactions within the broader Cucurbitaceae family have been documented clinically.

9. Regulatory and Monograph Status

In 2013, the EMA's Committee on Herbal Medicinal Products (HMPC) published a monograph recognizing the traditional use of C. pepo seeds for the relief of lower urinary tract symptoms associated with BPH or OAB based on long-standing medicinal use. ESCOP indicates the use of pumpkin seeds for urinary incontinence or overactive bladder in men and women. The European Pharmacopoeia (Ph. Eur.) specifies the Cucurbita pepo var. styriaca variety as the pharmacopeial reference material for Cucurbitae semen.

10. Evidence Strength Summary

• BPH / LUTS: Moderate but mixed. Multiple human clinical trials exist, including randomized controlled designs, but the largest RCT (GRANU) did not meet its primary endpoint. The EMA/HMPC grants only "traditional use" status, not "well-established use," reflecting this evidentiary limitation.
• Overactive bladder: Preliminary to moderate. Small clinical studies show benefit; one randomized double-blind trial shows benefit for a combination product, but single-ingredient pumpkin seed oil studies lack adequate placebo controls.
• Antidiabetic: Preliminary; predominantly animal/preclinical data. Human clinical data are sparse and not from large, rigorous RCTs.
• Cardiovascular / antihypertensive: Preliminary; animal data only for direct antihypertensive mechanisms.
• Anticancer: Preclinical (in vitro and animal) only; no human RCT data.
• Anthelmintic: Historically documented traditional use; modern clinical evidence absent.
• Wound healing: Animal model data only.

References

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• Profiling Hydrophilic Cucurbita pepo Seed Extracts: A Study of European Cultivar Variability — PMC (2025)
• Pumpkin Seed Oil Extracted From Cucurbita maxima Improves Urinary Disorder in Human Overactive Bladder — PMC (2014)
• Effects of Pumpkin Seed in Men with Lower Urinary Tract Symptoms due to BPH in the One-Year, Randomized, Placebo-Controlled GRANU Study — Urologia Internationalis / Karger (2015)
• Extract from Cucurbita pepo Improves BPH Symptoms without Affecting Sexual Function: A 24-Month Noninterventional Study — PMC / World Journal of Urology (2022)
• Pumpkin Seed Oil (Cucurbita pepo) versus Tamsulosin for Benign Prostatic Hyperplasia Symptom Relief: A Single-Blind Randomized Clinical Trial — PMC / BMC Urology (2021)
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