Two Novel Angiotensin-Converting Enzyme (ACE) Inhibitory and ACE2 Upregulating Peptides from the Hydrolysate of Pumpkin (Cucurbita moschata) Seed Meal.

Pumpkin (Cucurbita moschata) seed meal (PSM), the major byproduct of pumpkin seed oil industry, was used to prepare angiotensin-converting enzyme (ACE) inhibitory and angiotensin-converting enzyme 2 (ACE2) upregulating peptides. These peptides were isolated and purified from the PSM hydrolysate prepared using Neutrase 5.0 BG by ultrafiltration, Sephadex G-15 column chromatography, and reversed-phase high-performance liquid chromatography. Two peptides with significant ACE inhibition activity were identified as SNHANQLDFHP and PVQVLASAYR with IC50 values of 172.07 and 90.69 µM, respectively. The C-terminal tripeptides of the two peptides contained Pro, Phe, and Tyr, respectively, and PVQVLASAYR also had Val in its N-terminal tripeptide, which was a favorable structure for ACE inhibition. Molecular docking results declared that the two peptides could interact with ACE through hydrogen bonds and hydrophobic interactions. Furthermore, the two peptides performed protective function on EA.hy926 cells by decreasing the secretion of endothelin-1, increasing the release of nitric oxide, and regulating the ACE2 activity. In vitro simulated gastrointestinal digestion showed the two peptides exhibited good stability against gastrointestinal enzyme digestion. In conclusion, PSM is a promising material for preparing antihypertensive peptides.

Effect of Cucurbita ficifolia Bouché on glutathione level and glycosylated hemoglobin percentage in a Mexican rural population with type 2 diabetes.

ETHNOPHARMACOLOGICAL IMPORTANCE: Cucurbita ficifolia Bouché fruit is widely used in Mexican traditional medicine to treat type 2 diabetes (T2D) because it has been attributed with antioxidant and hypoglycemic properties in different experimental models and T2D patients. An imbalance in physiological glutathione (GSH) concentrations increases the susceptibility to developing complications associated with oxidative stress in T2D patients. AIM OF THE STUDY: To investigate the effect of C. ficifolia on the antioxidant properties of GSH, general health measurements, and biochemical parameters in a Mexican rural population, and to evaluate the changes in socio-affective scores of patients due to improvement in T2D. MATERIALS AND METHODS: Twenty-seven women diagnosed with T2D with poor glycemic control volunteered and were divided into two groups: C. ficifolia (0.5 g/kg of fresh pulp weight) with hypoglycemic pharmacotherapy, and another group with only hypoglycemic pharmacotherapy, for 12 weeks. We evaluated the effect of the fresh pulp of C. ficifolia on body mass index, blood pressure, glucose, glycosylated hemoglobin, cholesterol, triglycerides, and GSH. Expanding the study, we evaluated the quality of life, anxiety, and depression scores before and after the intervention. RESULTS: Treatment with the fresh pulp of C. ficifolia for 12 weeks reduced glycosylated hemoglobin, similar to the hypoglycemic pharmacotherapy group, and significantly increased GSH concentrations. The patients' moods did not change despite increased GSH concentrations and improved T2D control. CONCLUSIONS: The increased GSH concentrations due to the consumption of fresh pulp of C. ficifolia could help to protect against oxidative stress and extend therapeutic benefits in addition to the usual hypoglycemic drugs in patients with T2D.

Pumpkin seed oil: a comprehensive review of extraction methods, nutritional constituents, and health benefits.

Pumpkin seed oil (PSO), a rich source of nutrients, is extracted from the seeds of different pumpkin varieties for food and medicines. This article aims to provide an evidence-based review of the literature and to explore the extraction technologies, nutritional properties, and biological activity of PSO. From previous literature, PSO contains a large proportion of unsaturated fatty acids, with linoleic acid as the main component, and an amount of tocopherol, phytosterol, and phenolic acids. Some differences in the yield, composition, and physicochemical properties of PSO can be associated with the pumpkin's cultivars and the extraction methods. Some novel technologies involved in supercritical fluid extraction, enzyme-assisted aqueous extraction, and ultrasound-assisted extraction have been replacing the conventional technologies gradually as promising methods for the safe, non-polluting, and effective recovery of PSO. This healthy vegetable oil was reported by several in vitro and in vivo studies to have potential protective roles in oxidative stress, inflammation, cancer, and cardiovascular diseases. © 2023 Society of Chemical Industry.

Comparative Analysis of Traditional Oriental Herbal Fruits as Potential Sources of Polyphenols and Minerals for Nutritional Supplements.

There are a plethora of plant species in India, which have been widely used in vegetable dishes, soups, desserts and herbal medicine. In addition to these traditional uses, today there is the extra possibility of also being able to use these plants in the nutritional supplements industry due to their favorable antioxidant and mineral composition. In this sense, thirteen vegetable species-Chanania lanzan, Ziziphus mauritiana, Nilumbo nucifera, Terminalia catappa, Terminalia arjuna, Terminalia bellirica, Terminalia chebula, Lagenaria siceraria, Luffa aegyptiaca, Praecitrullus fistulosus, Benincasa hispida, Citrullus lanatus var. lanatus and Cucurbita maxima-have been analyzed. In this paper we discuss the distribution of polyphenols and minerals (Na, K, Mg, Ca, Al, P, S, Cr, Mn, Fe, Cu, Zn, Mo, As and Pb) in different seed parts (the rhizome, pericarp, carpel, seed coat and kernel) of the above species and their possible use in the nutritional supplements industry. The concentrations of total polyphenols, flavonoids and minerals ranged from 407 to 3144 mg rutin hydrate/100 g, 24 to 3070 mg quercetin/100 g and 1433 to 7928 mg/100 g, respectively. K, Ca, P and S were abundant in these herbal fruits. In two species of herbal fruits, Terminalia arjuna and Terminalia chebula, only part of the seed structure was suitable for use in nutritional supplements.

Can pumpkin save us of doxorubicin induced cardiotoxicity? / ¿Puede la calabaza salvarnos de la cardiotoxicidad inducida por doxorrubicina?

SUMMARY: Doxorubicin (DOX) is one of the drugs necessary for the treatment of the 10 most common types of cancer. The leading adverse effect limiting clinical use of DOX is cardiotoxicity. Given that literature data indicate a protective role of carotenoids in doxorubicin-induced toxicity, in our study we compared the cardioprotective effect of a mixture of pumpkin carotenoids and a commercially available antioxidant preparation. Animals were distributed in 8 groups (Control - S; NADES - N; Doxorubicin - Dox; Carotenoids - Car; CardiofortIN - CF; NADES-Doxorubicin - N-Dox; Carotenoids-Doxorubicin - Car-Dox; CardiofortIN-Doxorubicin - CF-Dox). Histological sections were stained with the hematoxylin-eosin (HE) and analyzed for the presence of myocardial damage by doxorubicin damage score (DDS). From the heart tissue homogenate were determined the intensity of lipid peroxidation and specific antioxidative enzyme activity (superoxide dismutase; catalase; glutathione S-transferase; glutathione peroxidase). In Car-DOX and CF-DOX groups, lipid peroxidation is significantly reduced compared to DOX group. Pretreatment of animals with carotenoids and in lesser extent with CardiofortIN led to higher antioxidative enzymes activity, compared to DOX group. Pretreated with carotenoids, only 50 % of animals had some degree of myocardial damage, and no animals had extensive damage. CardiofortIN pretreatment showed less protective effect. Pretreatment with carotenoid extract, reduced DDS significantly, so Car-DOX group has changes equivalent to mild myocardial damage. Although CardiofortIN pretreatment lowered DDS score values, animals still had moderate level of myocardium damage. This in vivo study and its findings indicate that carotenoids extracted from pumpkin may be a promising cardioprotective agent against doxorubicin induced cardiotoxicity, at least in part mediated through inhibition of DOX-induced oxidative stress.

La doxorrubicina (DOX) es uno de los fármacos necesarios para el tratamiento de los 10 tipos más comunes de cáncer. El principal efecto adverso que limita el uso clínico de DOX es la cardiotoxicidad. Debido a que los datos de la literatura indican un papel protector de los carotenoides en la toxicidad inducida por doxorrubicina, en nuestro estudio comparamos el efecto cardioprotector de una mezcla de carotenoides de calabaza y una preparación antioxidante disponible comercialmente. Los animales se distribuyeron en 8 grupos (Control - S; NADES - N; Doxorrubicina - Dox; Carotenoides - Car; CardiofortIN - CF; NADES-Doxorrubicina - N-Dox; Carotenoides-Doxorrubicina - Car-Dox; CardiofortIN- Doxorrubicina - CF-Dox). Las secciones histológicas se tiñeron con hematoxilina-eosina (HE) y se analizaron para detectar la presencia de daño miocárdico mediante la puntuación de daño por doxorrubicina (DDS). A partir del homogeneizado de tejido cardíaco se determinó la intensidad de la peroxidación lipídica y la actividad enzimática antioxidante específica (superóxido dismutasa, catalasa, glutatión S-transferasa, glutatión peroxidasa). En los grupos Car-DOX y CF-DOX, la peroxidación lipídica se redujo significativamente en comparación con el grupo DOX. El pre tratamiento de los animales con carotenoides y, en menor medida, con CardiofortlN condujo a una mayor actividad de las enzimas antioxidantes, en comparación con el grupo DOX. Al ser pre tratados con carotenoides, solo el 50 % de los animales tenían algún grado de daño miocárdico y ningún animal tenía daño extenso. El pre tratamiento con CardiofortIN mostró un efecto protector menor. El pre tratamiento con extracto de carotenoides redujo significativamente el DDS, por lo que el grupo Car-DOX mostró cambios equivalentes a un daño miocárdico leve. Aunque el pre tratamiento con CardiofortIN redujo los valores de la puntuación DDS, los animales aún tenían un nivel moderado de daño al miocardio. Este estudio in vivo y sus hallazgos indican que los carotenoides extraídos de la calabaza pueden ser un agente cardioprotector prometedor contra la cardiotoxicidad inducida por doxorrubicina, al menos en parte mediada por la inhibición del estrés oxidativo inducido por DOX.

Statistical optimization and characterization of fucose-rich polysaccharides extracted from pumpkin (Cucurbita maxima) along with antioxidant and antiviral activities.

Biologically active phytochemicals from pumpkin reveal versatile medical applications, though little is known about their antiviral activity. The fucose-rich polysaccharide extraction conditions were optimized through Box-Behnken design and purified by column chromatography. The purified fucose-rich polysaccharide was characterized through SEM, FT-IR, 1H NMR, XRD, TGA, and GS-MS. The analysis results revealed an irregular and porous surface of the purified polysaccharide with high fucose, rhamnose, galactose, and glucose contents. The tested fucose-rich polysaccharides revealed significant antioxidant and anti-inflammatory activity at very low concentrations. The purified fucose-rich polysaccharides exerted a broad-spectrum antiviral activity against both DNA and RNA viruses, accompanied by high safety toward normal cells, where the maximum safe doses (EC100) were estimated to be about 3-3.9 mg/mL for both Vero and PBMC cell lines. Treatment of HCV, ADV7, HSV1, and HIV viruses with the purified polysaccharides showed a potent dose-dependent inhibitory activity with IC50 values of 95.475, 20.96, 5.213, and 461.75 µg/mL, respectively. This activity was hypothesized to be through inhibiting the viral entry in HCV infection and inhibiting the reverse transcriptase activity in HIV. The current study firstly reported the antioxidant, anti-inflammatory, and antiviral activities of Cucurbita maxima fucose-rich polysaccharide against several viral infections.

Cold pressed pumpkin seed oil fatty acids, carotenoids, volatile compounds profiles and infrared fingerprints as affected by storage time and wax-based oleogelation.

BACKGROUND: Pumpkin seed and sunflower oil are rich in bioactive compounds, but are prone to oxidation during storage. Their fatty acids, carotenoid and volatile compounds and their Fourier-transform infrared (FTIR) profiles were studied during 8 months storage in order to assess the overall quality, but also to assess the impact of the oleogelation as conditioning process. RESULTS: The fatty acids methyl esters were analyzed by gas chromatography-mass spectrometry (GC-MS). The linoleic acid was the most abundant in the oils (604.6 g kg-1 in pumpkin and 690 g kg-1 in sunflower), but also in oleogels. Through high-performance liquid chromatography (HPLC), lutein and ß-carotene were determined as specific carotenoid compounds of the pumpkin seed oil and oleogel, in a total amount of 0.0072 g kg-1 . The volatile compounds profile revealed the presence of alpha-pinene for the pumpkin seed oil and oleogels and a tentative identification of limonene for the sunflower oil. Hexanal was also detected in the oleogels, indicating a thermal oxidation, which was further analyzed through infrared spectroscopy. CONCLUSIONS: During 8 months storage, the decrease of polyunsaturated fatty acid total amount was 5.72% for the pumpkin seed oil and 3.55% for the oleogel, while in the sunflower oil samples of 2.93% and 3.28% for the oleogel. It was concluded that oleogelation might protect specific carotenoid compounds, since the oleogels displayed higher content of ß-carotene at each storage time. Hexanal and heptanal were detected during storage, regardless of the oil or oleogel type. FTIR analysis depicts the differences in the constituent fatty acids resulting due to thermal oxidation or due to storage. © 2022 Society of Chemical Industry.

The Physical and Chemical Characteristics of Seeds Oil of Local Sudanese Pumpkin (Cucurbita moschata Duchesne).

This study aimed to evaluate the physical and chemical properties of pumpkin (Cucurbita moschata Duchesne) seed oil obtained from local Sudanese pumpkins. Three different genotypes of the pumpkin fruits as round, elongated and bell shapes were collected from Elgadarif State, Sudan. The oil's seeds' physical and chemical characteristics were determined by viscosity, specific gravity, refractive index, oil content peroxide value, acid value, saponification, unsaponifiable, pH, iodine value, total polyphenols and fatty acid content. The results revealed that there were significant (p < 0.05) differences in the oil content and chemical characteristics (except acid value and pH) of oil among the different pumpkin fruit genotypes. Linoleic and oleic acids were the primary fatty acids among the different pumpkin fruit genotypes. However, there were no significant (p < 0.05) differences in the fatty acid content and physical properties of the seed's oil. The high oil content, phenolic content and essential fatty acids indicated that the obtained oil from different local Sudanese pumpkins might impart health and nutritional benefit when involved in the food industry as a natural resource.

The potential of pumpkin seed oil as a functional food-A comprehensive review of chemical composition, health benefits, and safety.

The growing interest in foods that can be beneficial to human health is bringing into focus some products that have been used locally for centuries but have recently gained worldwide attention. One of these foods is pumpkin seed oil, which has been used in culinary and traditional medicine, but recent data also show its use in the pharmaceutical and cosmetic industries. In addition, some sources refer to it as a potential functional food, mainly because it is obtained from pumpkin seeds, which contain many functional components. However, the production process of the oil may affect the content of these components and consequently the biological activity of the oil. In this review, we have focused on summarizing scientific data that explore the potential of pumpkin seed oil as a functional food ingredient. We provide a comprehensive overview of pumpkin seed oil chemical composition, phytochemical content, biological activity, and safety, as well as the overview of production processes and contemporary use. The main phytochemicals in pumpkin seed oil with health-related properties are polyphenols, phytoestrogens, and fatty acids, but carotenoids, squalene, tocopherols, and minerals may also contribute to health benefits. Most studies have been conducted in vitro and support the claim that pumpkin seed oil has antioxidant and antimicrobial activities. Clinical studies have shown that pumpkin seed oil may be beneficial in the treatment of cardiovascular problems of menopausal women and ailments associated with imbalance of sex hormones.

Identification of zinc-chelating pumpkin seed (Cucurbita pepo L.) peptides and in vitro transport of peptide-zinc chelates.

In this study, pumpkin seeds peptide was purified, characterized, and evaluated for their zinc-chelating capability, as well as in vitro bioaccessibility and transportation. Raw pumpkin seeds protein hydrolysate (PSPH) was produced by papain hydrolysis. The peptide fractions with the highest zinc-chelating abilities were purified using immobilized metal affinity chromatography (IMAC) followed by gel filtration chromatography (GF). Eight peptides were identified, two of which with the lowest molecular weights were synthesized (RPKHPLK and RPKHPLSHDL) for determining potential bioaccessibility and bioavailability. Our results showed that the gastrointestinal stability of RPKHPLK-Zn and RPKHPLSHDL-Zn was higher than that of inorganic zinc salts in the simulated gastrointestinal tract model. Furthermore, the influence of the peptide zinc chelates on zinc transport was explored in vitro using Caco-2 cell monolayer model. It was also shown that both RPKHPLK-Zn and RPKHPLSHDL-Zn could increase zinc transport rate and may be used to facilitate effective zinc absorption. The result of this study may provide important implications for developing plant protein foods with higher nutritional value. PRACTICAL APPLICATION: As a potential alternative protein source, pumpkin seeds may find promising applications in plant-based foods and drinks to meet the growing market for nonanimal foods. In this study, pumpkin seed protein peptides were prepared and purified, and the zinc-chelating peptides were identified and evaluated for the abilities to promote the uptake of zinc. This type of mineral peptide chelates could be incorporated into plant-based foods to increase mineral contents, which is significantly higher in foods originated from animals. The result of our study may provide important information for food industry to increase the nutritional value of plant-based foods.

Defensive Mechanisms in Cucurbits against Melon Fly (Bactrocera cucurbitae) Infestation through Excessive Production of Defensive Enzymes and Antioxidants.

Melon fly (Bactrocera cucurbitae) is the most common pest of cucurbits, and it directly causes damage to cucurbit fruits in the early developmental stage. The infection of fruit tissues induces oxidative damage through increased generation of cellular reactive oxygen species. The effects of melon fly infestation on the production of defensive enzymes and antioxidant capabilities in five cucurbit species, namely, bottle gourd, chayote, cucumber, snake gourd, and bitter gourd, were investigated in this study. The total phenolic and flavonoid content was considerably higher in melon fly infestation tissues compared to healthy and apparently healthy tissues. The chayote and bottle gourd tissues expressed almost 1.5- to 2-fold higher phenolic and flavonoid contents compared to the tissues of bitter gourd, snake gourd, and cucumber upon infestation. Defensive enzymes, such as peroxidase (POD), superoxide dismutase (SOD), polyphenol oxidase (PPO), and catalase (CAT), were high in healthy and infected tissues of chayote and bottle gourd compared to bitter gourd, snake gourd, and cucumber. The activity of POD (60-80%), SOD (30-35%), PPO (70-75%), and CAT (40-50%) were high in infected chayote and bottle gourd tissue, representing resistance against infestation, while bitter gourd, snake gourd, and cucumber exhibited comparatively lower activity suggesting susceptibility to melon fly infection. The antioxidant properties were also high in the resistant cucurbits compared to the susceptible cucurbits. The current research has enlightened the importance of redox-regulatory pathways involving ROS neutralization through infection-induced antioxidative enzymes in host cucurbit resistance. The melon fly infestation depicts the possible induction of pathways that upregulate the production of defensive enzymes and antioxidants as a defensive strategy against melon fly infestation in resistant cucurbits.

Hydrothermal Processing and In Vitro Simulated Human Digestion Affects the Bioaccessibility and Bioactivity of Phenolic Compounds in African Pumpkin (Momordica balsamina) Leaves.

The African pumpkin (Momordica balsamina) contains bioactive phenolic compounds that may assist in reducing oxidative stress in the human body. The leaves are mainly consumed after boiling in water for a specific time; this hydrothermal process and conditions of the gastrointestinal tract may affect the presence and bioactivity of phenolics either positively or negatively. In this study, the effects of hydrothermal processing (boiling) and in vitro simulated human digestion on the phenolic composition, bioaccessibility and bioactivity in African pumpkin were investigated in comparison with those of spinach (Spinacia oleracea). A high-resolution ultra-performance liquid chromatography, coupled with diode array detection, quadrupole time-of-flight and mass spectrometer (UPLC-DAD-QTOF-MS) was used to profile phenolic metabolites. Metabolites such as 3-caffeoylquinic acid, 5-caffeoylquinic acid, 3,4-dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid and 4,5-dicaffeoylquinic acid were highly concentrated in the boiled vegetable extracts compared to the raw undigested and all digested samples. The majority of African pumpkin and spinach extracts (non-digested and digested) protected Deoxyribonucleic acid (DNA), (mouse fibroblast) L929 and human epithelial colorectal adenocarcinoma (Caco-2) cells from 2,2'-Azobis(2-methylpropionamidine) dihydrochloride (AAPH)-induced oxidative damage. From these results, the consumption of boiled African pumpkin leaves, as well as spinach, could be encouraged, as bioactive metabolites present may reduce oxidative stress in the body.

Study on the emulsification and oxidative stability of ovalbumin-pectin-pumpkin seed oil emulsions using ovalbumin solution prepared by ultrasound.

Pumpkin seed oil (PSO), which is a valuable compound with high nutritional value used for the prevention of various chronic diseases, is prone to oxidation. In this work, small and uniform (su) ovalbumin (OVA) and pectin (PEC) were used to stabilize PSO in the form of an emulsion. The results showed that suOVA-PEC-PSO emulsion with a droplet size of 9.82 ± 0.05 µm was successfully self-assembled from PSO, PEC, and suOVA solution (with a droplet size of 230.13 ± 14.10 nm) treated with 300 W ultrasound, owing to the formation of a more stable interfacial film on the surface of droplets. The interfacial, rheological, emulsifying, and antioxidant properties of the suOVA-PES-PSO emulsions were excellent, owing to the synergistic effects between PEC and suOVA solution. Moreover, the physical stability of the suOVA-PEC-PSO emulsions to salt stress, a freeze-thaw cycle, and heat treatment was also increased and the oxidation of linolenic acid was notably delayed. These results have extended the food-related applications of OVA and PSO, and provide a promising foundation for further exploration of the self-assembly of composite emulsions by small and uniform proteins.

Characterization of a neutral polysaccharide from pumpkin (Cucurbita moschata Duch) with potential immunomodulatory activity.

A neutral polysaccharide designated as CMDP-1a (molecular mass 9.263 kDa) was isolated from Cucurbita moschata Duch through hot water extraction, ethanol precipitation, and column chromatography. On the basis of methylation, fourier-transform infrared, monosaccharide composition, and one- and two-dimensional nuclear magnetic resonance spectroscopy analyses, the structure of CMDP-1a was determined to be a backbone composed of α-1,4 linked glucopyranosyl residues with α-Glcp residue linkage at backbone C-6. Atomic force microscopy and scanning electron microscopy analyses revealed that CMDP-1a had a spherical conformation in solution. In immunostimulation assays, CMDP-1a promoted the proliferation of RAW 264.7 macrophages and significantly enhanced their pinocytic and phagocytic capacity. Furthermore, CMDP-1a induced the M1 polarization of original macrophages and the conversion of macrophages from M2 to M1, thereby modulating the balance of M1/M2 macrophages. These results indicated that CMDP-1a might be a potential immunomodulator for food purposes.

Structural characterization and mechanisms of macrophage immunomodulatory activity of a pectic polysaccharide from Cucurbita moschata Duch.

A pectic polysaccharide (named CMDP-4b) with a molecular weight of 31.97 kDa was extracted from Cucurbita moschata Duch and purified by column chromatography. On the basis of methylation, Fourier-transform infrared, monosaccharide composition, and one- and two-dimensional nuclear magnetic resonance spectroscopy analyses, the structure of CMDP-4b was determined to be composed of an α-1,4-linked homogalacturonan backbone, which was slightly acetylated and highly methyl-esterified, and branched at the O-3 position of the →4)-α-D-GalpA-6-OMe-(1→. Immunomodulatory assays showed that CMDP-4b not only induced the secretion of nitrous oxide and cytokines (i.e. IL-1ß, TNF-α, and IL-6) but also promoted pinocytic and phagocytic activities of macrophages, suggesting that CMDP-4b possessed immunomodulatory activity. Moreover, toll-like receptor 4 and complement receptor 3 may play a critical role in CMDP-4b-induced macrophage activation through the NF-κB and the MAPKs signaling pathways. Our study provides the molecular basis for the potential use of CMDP-4b as a natural immunostimulant.

The Influence of Ripeness on the Phenolic Content, Antioxidant and Antimicrobial Activities of Pumpkins (Cucurbita moschata Duchesne).

Cucurbita moschata Duchesne (Cucurbitaceae) is a plant food highly appreciated for the content of nutrients and bioactive compounds, including polyphenols and carotenoids, which contribute to its antioxidant and antimicrobial capacities. The purpose of this study was to identify phenolic acids and flavonoids of Cucurbita moschata Duchesne using high-performance liquid chromatography-diode array detection-electrospray ionization tandem mass spectrometry (HPLC-DAD-ESI-MS) at different ripening stages (young, mature, ripened) and determine its antioxidant and antimicrobial activities. According to the results, phenolic acids and flavonoids were dependent on the maturity stage. The mature fruits contain the highest total phenolic and flavonoids contents (97.4 mg GAE. 100 g-1 and 28.6 mg QE. 100 g-1).A total of 33 compounds were identified. Syringic acid was the most abundant compound (37%), followed by cinnamic acid (12%) and protocatechuic acid (11%). Polyphenol extract of the mature fruits showed the highest antioxidant activity when measured by DPPH (0.065 µmol TE/g) and ABTS (0.074 µmol TE/g) assays. In the antimicrobial assay, the second stage of ripening had the highest antibacterial activity. Staphylococcus aureus was the most sensitive strain with an inhibition zone of 12 mm and a MIC of 0.75 mg L-1. The lowest inhibition zone was obtained with Salmonella typhimurium (5 mm), and the MIC value was 10 mg L-1.

Fermentation as a tool for increasing food security and nutritional quality of indigenous African leafy vegetables: the case of Cucurbita sp.

Sub-Saharan region is often characterized by food and nutrition insecurity especially "hidden hunger" which results from inadequate micronutrients in diets. African indigenous leafy vegetables (AILVs) can represent a valid food source of micronutrients, but they often go to waste resulting in post-harvest losses. In an attempt to prolong AILVs shelf-life while enhancing their nutritional quality, fermentation was studied from a microbiological and nutritional point of view. Pumpkin leaves (Cucurbita sp.) were spontaneously fermented using the submerged method with 3% NaCl and 3% sucrose. Controls were set up, consisting of leaves with no additions. During fermentation, samples of both treatments were taken at 0, 24, 48, 72 and 168 h to monitor pH and characterize the microbial population through culture-based and molecular-based analyses. Variations between fresh and treated leaves in B-group vitamins, carotenoids, polyphenols, and phytic acid were evaluated. Data revealed that the treatment with addition of NaCl and sucrose hindered the growth of undesired microorganisms; in controls, unwanted microorganisms dominated the bacterial community until 168 h, while in treated samples Lactobacillaceae predominated. Furthermore, the content in folate, ß-carotene and lutein increased in treated leaves compared to the fresh ones, while phytic acid diminished indicating an amelioration in the nutritional value of the final product. Thus, fermentation could help in preserving Cucurbita sp. leaves, avoiding contamination of spoilage microorganisms and enhancing the nutritional values.

Pumpkin Seed Extracts Inhibit Proliferation and Induce Autophagy in PC-3 Androgen Insensitive Prostate Cancer Cells.

Pumpkin seed is a rich source of polyphenols and other bioactive compounds that may act as chemopreventive agents against cancer. In this study, five different extracts of pumpkin seeds were evaluated for their ability to affect proliferation and autophagy on PC-3 prostate cancer cells. All extracts (water [W], methanolic, acetone, ethylacetate, and polar lipid [PL]) inhibited cell proliferation in a dose-dependent manner. Treatment of cells with the PL extract increased cell distribution in the S phase, whereas PL and W extracts induced autophagy significantly. Moreover, PL extract induced a remarkable increase of glutathione and oxidized glutathione levels, whereas nitrite and hydrogen peroxide levels were not altered. In conclusion, pumpkin seed extracts affect PC-3 cell viability, oxidative parameters, and autophagic mechanism, thus demonstrating their potential pharmacological use.

Antioxidant potential of family Cucurbitaceae with special emphasis on Cucurbita genus: A key to alleviate oxidative stress-mediated disorders.

Oxidative stress is the imbalance between reactive oxygen species (ROS) production, and accumulation and the ability of a biological system to clear these reactive products. This imbalance leads to cell and tissue damage causing several disorders in human body, such as neurodegeneration, metabolic problems, cardiovascular diseases, and cancer. Cucurbitaceae family consists of about 100 genera and 1,000 species of plants including mostly tropical, annual or perennial, monoecious, and dioecious herbs. The plants from Cucurbita species are rich sources of phytochemicals and act as a rich source of antioxidants. The most important phytochemicals present in the cucurbits are cucurbitacins, saponins, carotenoids, phytosterols, and polyphenols. These bioactive phyto-constituents are responsible for the pharmacological effects including antioxidant, antitumor, antidiabetic, hepatoprotective, antimicrobial, anti-obesity, diuretic, anti-ulcer activity, and antigenotoxic. A wide number of in vitro and in vivo studies have ascribed these health-promoting effects of Cucurbita genus. Results of clinical trials suggest that Cucurbita provides health benefits for diabetic patients, patients with benign prostate hyperplasia, infertile women, postmenopausal women, and stress urinary incontinence in women. The intend of the present review is to focus on the protective role of Cucurbita spp. phytochemicals on oxidative stress-related disorders on the basis of preclinical and human studies. The review will also give insights on the in vitro and in vivo antioxidant potential of the Cucurbitaceae family as a whole.

Comparison of physical, microstructural and antioxidative properties of pumpkin cubes cooked by conventional, vacuum cooking and sous vide methods.

BACKGROUND: Current dietary guidelines recommend five or more fruit, vegetable, and legume servings per day. Often, these products are eaten cooked, resulting in organoleptic and nutritional changes. Vacuum cooking is gaining attention as an alternative cooking technique, due to its ability to preserve or even enhance sensory and healthy properties of food. Its household application is, however, poorly explored. In this work, the effect of vacuum cooking, performed with a new patented system, was studied for the first time on pumpkin cubes and compared to sous vide and traditional steam cooking, through a multidisciplinary approach. RESULTS: All the cooking treatments damaged pumpkin microstructure, leading to cell separation and plasmolysis; vacuum cooking was the most aggressive method, as confirmed by texture softening. Vacuum cooking was also the method with less impact on pumpkin color, in relation to the largest extraction of some classes of carotenoids from the broken cells. Significant polyphenol extraction, especially of gallic acid and naringenin, was instead observed for sous vide and steamed pumpkins. The total antioxidant activity, ascribable to the effect of both carotenoids and polyphenols, resulted enhanced after cooking compared to raw one mainly for cook vide samples, followed by steamed and sous vide ones. CONCLUSIONS: Vacuum cooking, followed by sous vide, has often shown better performance than traditional steam cooking for pumpkin cubes. The implementation of sous vide and vacuum cooking at domestic level or in professional kitchens, and in the food industry, would allow the consumption of vegetables with improved nutritional and sensorial characteristics. © 2020 Society of Chemical Industry.