Assessment of Cucurbita spp. Peel Extracts as Potential Sources of Active Substances for Skin Care and Dermatology.

By-products of cultivated plants are one of the major environmental concerns worldwide. Due to the high concentration of bioactive chemicals, such waste may be considered hazardous due to the interference with the plant growth, deterioration of the drinking water quality or toxic effects on sensitive marine organisms. Moreover, plant-derived by-products, with proper handling, may represent a low-cost source of bioactive compounds potentially important for pharmaceutical and cosmetics industries. The aim of the study was to evaluate the phytochemical composition, antioxidant activity, the influence of tyrosinase activity, in vitro sun protecting factor and cytotoxicity of 15 extracts from peels of five cultivars of Cucurbita maxima and C. moschata. The extracts were prepared using "green solvents" (water, 50% propylene glycol, and 20% ethanol) and ultrasound-assisted extraction. The performed analysis showed that the peel extracts from various cultivars differ significantly in respect to the phytochemical content and activity. The type of solvent also had a significant impact on the extract's composition and bioactivity. Aqueous peel extracts contained the highest amounts of flavonoids, showed the greatest antioxidant potential and the most significant in vitro SPF values. In vitro studies showed that the analyzed peel extracts are not cytotoxic for human keratinocytes up to the concentration of 1000 µg/mL and thus might be considered as non-irritant for the skin. The study confirms the potential application of peel extracts from Cucurbita spp. cultivars in cosmetic products.

Levels of residues and dietary risk assessment of the fungicides myclobutanil, penconazole, tebuconazole, and triadimenol in squash.

Triazole fungicides may potentially harm human health. The 'quick, easy, cheap, effective, rugged, and safe' approach has become popular for extraction and cleanup during pesticide residue analysis. We aimed to (a) validate a method for the simultaneous determination of myclobutanil, penconazole, tebuconazole, and triadimenol in squash using LC-MS/MS and (b) determine the pre-harvest intervals (PHIs) and assess the related risk of consuming squash cultivated under open-field conditions in Saudi Arabia. Using acetonitrile as the extraction solvent and fourfold dilution in deionized water led to weak signal suppression (<-6.1%). The limits of quantitation ranged from 10 to 40 µg/kg. Mean recovery and relative standard deviation ranged from 81.7 to 96.3% and from 3.6 to 11.4%. The half-lives ranged from 2.22 to 3.83 days, and the dissipation followed first-order kinetics. The terminal residues of myclobutanil, penconazole, tebuconazole, and triadimenol were <0.771, <0.307, <0.459, and <0.954 mg/kg, respectively, 7 days after two or three applications of recommended dosages. The PHIs of 7.1-11.4, 8.7-13.1, 3.8-5.3, and 11.3-14.3 days are suggested after the application of the recommended dose and double the recommended dose. A consumer risk assessment based on estimated dietary intake indicated that the consumption of squash treated with the recommended doses does not pose a significant health risk.

LC-MS/MS-Based Profiling of Tryptophan-Related Metabolites in Healthy Plant Foods.

Food plants contain hundreds of bioactive phytochemicals arising from different secondary metabolic pathways. Among these, the metabolic route of the amino acid Tryptophan yields a large number of plant natural products with chemically and pharmacologically diverse properties. We propose the identifier "indolome" to collect all metabolites in the Tryptophan pathway. In addition, Tryptophan-rich plant sources can be used as substrates for the fermentation by yeast strains to produce pharmacologically active metabolites, such as Melatonin. To pursue this technological development, we have developed a UHPLC-MS/MS method to monitor 14 Tryptophan, Tryptamine, amino-benzoic, and pyridine metabolites. In addition, different extraction procedures to improve the recovery of Tryptophan and its derivatives from the vegetal matrix were tested. We investigated soybeans, pumpkin seeds, sesame seeds, and spirulina because of their botanical diversity and documented healthy effects. Four different extractions with different solvents and temperatures were tested, and water extraction at room temperature was chosen as the most suitable procedure to extract the whole Tryptophan metabolites pattern (called by us "indolome") in terms of ease, high efficiency, short time, low cost, and sustainability. In all plant matrices, Tryptophan was the most abundant indole compound, while the pattern of its metabolites was different in the diverse plants extracts. Overall, 5-OH Tryptamine and Kynurenine were the most abundant compounds, despite being 100-1000-fold lower than Tryptophan. Melatonin was undetected in all extracts, but sesame showed the presence of a Melatonin isomer. The results of this study highlight the variability in the occurrence of indole compounds among diverse food plants. The knowledge of Tryptophan metabolism in plants represents a relevant issue for human health and nutrition.

Oxidative enzymes from newly local strain Aspergillus iizukae EAN605 using pumpkin peels as a production substrate: Optimized production, characterization, application and techno-economic analysis.

The present study deals with optimizing, producing, characterizing, application and techno- economic analysis of oxidative enzymes [Laccase (Lac), manganese peroxidase (MnP), and lignin peroxidase (LiP)] from Aspergillus iizukae EAN605 in submerged fermentation process using pumpkin peels as a production substrate. The best operating parameters for producing Lac, MnP and LiP (6.15, 2.58 and 127.99 U mg-1 respectively) were recorded with 20 g 100 mL-1 of substrate, 4.6 mL 100 mL-1 of inoculum size at pH 5.5 after 10 days. The crude enzyme exhibited high stability at pH (3-9) and temperatures (20-60 °C). Km (Michaelis-Menten) of Lac, MnP and LiP crude enzyme was 2.25, 1.79 and 0.72 mM respectively. The decolourization of Remazol Brilliant Blue R by the crude enzyme was 84.84 %. The techno-economic analysis was assessed for a production unit with an annual operating time for enzymatic production and application is 7920 h/year and 100 m3 of the capacity. The process would produce 27,000 cm3 of crude enzyme with a price of USD 0.107 per cm3 compared to USD 1 per cm3 of the current commercial enzyme. The findings indicated that pumpkin peels have potential as a production substrate for oxidative enzymes from A. iizukae EAN605 and is economically feasible.

Development of a new adsorbent from pumpkin husk by KOH-modification to remove copper ions.

Heavy metal pollution in watercourses is a major environmental problem throughout the world due to rapid population growth, industrialization, and economic development. Considering this, the present study aimed to develop a new adsorbent from pumpkin husk (PH) by KOH modification to remove copper (Cu2+) ions and to explore its adsorptive potential. The sorption studies of Cu2+ on KOH-modified PH were carried out as functions of particle size, solution pH, adsorbent dose, temperature, initial metal concentration, and contact time. The sorption capacity of KOH-modified PH was found to be higher than that of raw PH, as 19.4 and 10.2 mg g-1, respectively. Morphology and surface structures of adsorbents were characterized by determination of zero point charge, a Fourier transform infrared spectrometer (FTIR-ATR) spectra, and a scanning electron microscopy (SEM) of PH powders before and after the sorption of Cu2+. The pHzpc of PH was found to be 5.0. FTIR-ATR analyses indicated that amino, amide, hydroxyl, carboxyl, and oxygenated groups of PH play an important role in the sorption process. Sorption isotherm, kinetic, and thermodynamic parameters of Cu2+ on KOH-modified PH were studied. The kinetic process was well represented by the Logistic model. The maximum sorption was found as 73.16 mg g-1 according to the well-fitting of Langmuir isotherm. Results of sorption and thermodynamic studies indicated that the process was exothermic, being feasible, and spontaneous. KOH-modified PH as an eco-friendly adsorbent had great potential to remove Cu2+ ions from aquatic system.

Safety assessment and toxicological profiling of a novel combinational sunprotective dermal formulation containing melatonin and pumpkin seed oil.

Ultraviolet (UV) radiation exposure has been known to cause irreparable damages to human skin. The daunting risk of UV radiation exposure faced by military personnel led to the development of a sunscreen formulation which has superior sun protection factor combined with the ability to counteract reactive oxygen species. The present work deals with the preclinical safety evaluation of the sunscreen formulation comprising of four US FDA approved UV filters; namely avobenzone, octinoxate, oxybenzone, titanium dioxide along with melatonin and pumpkin seed oil, via OECD protocols of assessing acute oral and dermal toxicity; skin sensitizing; skin irritating; ocular irritating and genotoxic potential. Both oral and dermal LD50 values were found to be ˃2000 mg/kg body weight in adult Wistar albino rats using acute dermal and oral toxicity tests. The sunscreen formulation was found to be non-sensitizing to the skin of guinea pigs and non-irritating to both skin and eyes of rabbits. The sunscreen formulation was also found to be non-mutagenic which was affirmed by a battery of genotoxicity and muagenicity assays. The results obtained from this preclinical study indicated that the sunscreen formulation is non toxic and safe in animal models. This study along with additional preclinical evaluations may serve as a basis for considering the formulation as a potential candidate for further trials to establish its efficacy, tolerability and applicability.

Disappearance of six pesticides in fresh and processed zucchini, bioavailability and health risk assessment.

A field study was carried out on the dissipation of three insecticides and three fungicides during the freezing of zucchini. A simultaneous residue analysis method is validated using QuEChERS extraction with acetonitrile and CG-MS and LC-MS analysis. The residues detected after field application never exceeded the established maximum residue limits. The processing factors calculated (fresh product/frozen product) are lower than 1, indicating a clear influence of the stages of the freezing process, especially the washing and blanching. The in vitro study of bioavailability establishes a low percentage of stomach absorption capacity. The level of residues detected in fresh zucchini and the Estimated Daily Intake calculated for Spain suggest that there is no risk of acute toxicity due to dietary exposure.

Radioprotective potential of Lagenaria siceraria extract against radiation-induced gastrointestinal injury.

The cucurbits (prebiotics) were investigated as novel agents for radio-modification against gastrointestinal injury. The cell-cycle fractions and DNA damage were monitored in HCT-15 cells. A cucurbit extract was added to culture medium 2 h before irradiation (6 Gy) and was substituted by fresh medium at 4 h post-irradiation. The whole extract of the fruits of Lagenaria siceraria, Luffa cylindrica, or Cucurbita pepo extract enhanced G2 fractions (42%, 34%, and 37%, respectively) as compared with control (20%) and irradiated control (31%). With cucurbits, the comet tail length remained shorter (L. siceraria, 28 µm; L. cylindrica, 34.2 µm; C. pepo, 36.75 µm) than irradiated control (41.75 µm). For in vivo studies, L. siceraria extract (2 mg/kg body weight) was administered orally to mice at 2 h before and 4 and 24 h after whole-body irradiation (10 Gy). L. siceraria treatment restored the glutathione contents to 48.8 µmol/gm as compared with control (27.6 µmol/gm) and irradiated control (19.6 µmol/gm). Irradiation reduced the villi height from 379 to 350 µm and width from 54 to 27 µm. L. siceraria administration countered the radiation effects (length, 366 µm; width, 30 µm, respectively) and improved the villi morphology and tight junction integrity. This study reveals the therapeutic potential of cucurbits against radiation-induced gastrointestinal injury.

Bioactive compounds in lipid fractions of pumpkin (Cucurbita sp) seeds for use in food.

UNLABELLED: Seeds are considered to be agro-industrial residues, which can be used as source of macronutrients and/or raw material for extraction of vegetable oils, since they present great quantities of bioactive compounds. This study aimed to characterize the lipid fractions and the seeds of pumpkin (Cucurbita sp) varieties Nova Caravela, Mini Paulista, Menina Brasileira, and Moranga de Mesa aiming at using them in food. The chemical composition of the seeds was performed according to the official methods of American Oil Chemists' Society and Association of Official Analytical Chemists. Total carotenoids and phenolic compounds were determined by spectrophotometry, while the levels of tocopherols were analyzed by high efficiency liquid chromatography. It was noted that the seeds contain high amounts of macronutrients that are essential for the functioning of the human organism. As to total carotenoids, Mini Paulista and Menina Brasileira pumpkin varieties presented significant amounts, 26.80 and 26.03 µg/g, respectively. Mini Paulista and Nova Caravela pumpkin varieties showed high amounts of total phenolic compounds in the lipid fractions and in the seeds. It was also found that γ-tocopherol is the isomer that stood out in the lipid fractions and in the seeds, mainly in Menina Brasileira. Finally, the consumption of these seeds and use of lipid fractions provide the supply of large quantities of compounds that are beneficial for health and that may be potentially used in food, besides representing an alternative to better use of agro-industrial residues. PRACTICAL APPLICATION: Bioactive compounds, besides presenting basic nutritional functions, provide metabolic and physiological health benefits when consumed as part of the usual diet. Therefore, there is a growing interest in vegetable oils of special composition, such as the ones extracted from fruit seeds. The seeds of Cucurbita sp are shown to be promising sources of oils, and especially the Cucurbita moschata and maxima species have not yet been fully elucidated. For this reason, it becomes important to investigate the chemical composition and lipid fractions of these seeds, aiming to use them in food.

Comparison of waste pumpkin material and its potential use in extruded snack foods.

Material was produced from Crown pumpkin (Cucurbita maxima) processed from fractions of the fruit which are regarded as waste stream products (peel, flesh and seed). The flour from the three different fractions (peel, flesh and seed) of Crown pumpkin flour was incorporated into an extruded snack product formulation at levels 10%, 30% and 50% (w/w with corn grit) and processed in a twin-screw extruder to make 10 expanded snack products. Proximate analysis was carried out to determine the nutritional value of the raw pumpkin and pumpkin flour. A physical analysis of the product was used to determine its color, the expansion ratio, bulk density and texture. Inclusion of waste stream material (peel and seed) at 10%, yielded extruded products with similar expansion and density characteristics to the control sample; however, an inclusion of greater than 10% yielded significant challenges to product quality (hardness of the product).