Search Results (57)

Allium genus (Amaryllidaceae) is widely distributed in the Northern hemisphere. Some species, including garlic and onion, have been used since ancient times as both food ingredients and medicinal plants. Many reviews deal with the chemical constituents, particularly the typical sulfur compounds, as well as with Allium pharmacological properties, such as antimicrobial, anti-inflammatory, antioxidant, and cytotoxic activities. The bibliographic search performed in this review is mainly focused on the potential role of Allium species in inhibiting melanogenesis, which has been mainly assessed through the evaluation of the inhibitory properties on tyrosinase, the key enzyme in melanin biosynthesis. Two well established models for identifying potential skin-whitening agents have been used to assess the anti-melanogenic effects of Allium species, the mushroom tyrosinase and the murine melanoma B16 cell line. Here, a literature search from Scopus, Web of Science, and PubMed databases has been performed using the keywords “Allium”, “tyrosinase”, “anti-melanogenic”, and “melanogenesis”, combined by means of Boolean operators. Based on selected inclusion criteria, 32 eligible papers have been selected. The aim of this systematic review is to offer an overview of the species for which the ability to affect melanogenesis has been demonstrated to date, highlighting a new and emerging perspective on the potential therapeutic use of Allium species. The biological properties of isolated pure compounds and the negative outcomes have been also considered. Full article

Neoplastic disorders, particularly malignant carcinomas, are complex systemic diseases characterized by unregulated cellular proliferation, the invasion of adjacent tissues, and potential metastasis to distant bodily sites. Among the diverse spectrum of cancer subtypes, malignant melanoma is a highly aggressive form of cutaneous cancer originating in melanocytes, the pigment-producing cells resident in the skin. This malignancy is distinguished by its rapid and uncontrolled growth, as well as its propensity for metastasis to vital organs, thereby posing significant challenges to therapeutic intervention and prognostication. Early detection of melanoma is crucial for optimizing patient outcomes, as diagnosis at an advanced stage often yields a poor prognosis and limited treatment options. Diagnostic modalities for melanoma encompass comprehensive clinical evaluations by dermatologists; radiological imaging techniques such as ultrasonography, magnetic resonance imaging (MRI), computed tomography (CT) scans; and excisional biopsies for accurate histopathological assessment. Malignant melanoma is typically treated with surgery to remove the tumor, followed by immunotherapy to enhance the immune response, targeted therapy for tumors with specific genetic mutations, chemotherapy for advanced stages, radiation therapy to manage metastasis, and other adjunct therapies. This review presents the properties and possible adjunct therapeutic effects against malignant melanoma of quercetin found in the literature and explores, based on the observed physicochemical properties and biological activity, its potential development as a topical formulation for cutaneous application. Quercetin is a naturally occurring flavonoid compound abundant in various plant-based food sources, including apples, onions, berries, and citrus fruits, and has exhibited promising antiproliferative, antioxidant, and anticancer properties. Its distinctive biochemical structure enables quercetin to effectively neutralize reactive oxygen species and modulate key carcinogenic pathways, thereby rendering it a potential candidate for therapeutic intervention in managing malignant tumors, including melanoma. Full article

The bioactive components present in onion peel powder are a promising factor in preventing/treating obesity. Overweight/obesity causes metabolic changes, which can lead to leptin resistance in the central nervous system (CNS) and, thus, to structural and functional changes in the brain. Objectives: The presented study focused on evaluating the influence of a diet supplemented with onion peel powder on the immunoexpression of leptin receptors (LepRs) in the hippocampus in obese rats and the potential anti-obesity role of the onion in the brain. Methods: To induce obesity, the animals were given a high-energy chow containing lard and sucrose. Onion skin powder was used to modify the standard and high-energy diets (10.5 g per rat/week) of Wistar rats in a 14-week experiment followed by a brain IHC study. Results: The effect of the onion diet on the expression of neuronal LepRs and astrocytes in the hippocampus was analyzed. Obese animals receiving onion in the diet showed significant growth in the average number of immunoreactive LepR (LepR-IR) neurons (p = 0.00108) and their average size (p = 0.00168) in the CA1 field of the hippocampus. Meanwhile, in obese rats not given onion peel powder, a significant increase in the average density of astrocytes was observed (p < 0.0001). Conclusions: The increased density of astrocytes in the hippocampus of obese animals can probably have a beneficial effect on brain changes in overweight individuals. The inclusion of onion in the diet of overweight/obese individuals may lead to increased hippocampal neuroplasticity, manifested by changes in the immunoexpression of LepRs. It can be speculated that the observed changes have a protective effect on the CNS structures during obesity, but this undoubtedly requires further research. Full article

Gold nanoparticles (Au NPs) are a promising target for research due to their small size and the resulting plasmonic properties, which depend, among other things, on the chosen reducer. This is important because removing excess substrate from the reaction mixture is problematic. However, Au NPs are an excellent component of various materials, enriching them with their unique features. One example is hydrogels, which provide a good, easily modifiable base for multiple applications such as cosmetics. For this purpose, various compounds, including hyaluronic acid (HA) and its derivatives, are distinguished by their high water-binding capacity and many characteristics resulting from their natural origin in organisms, including biocompatibility, biodegradability, and tissue regeneration. In this work Au NPs were synthesized using a green chemistry method, either by using onion extract as a reductant or chemically reducing them with sodium citrate. A complete characterization of the nanoparticles was carried out using the following methods: Fourier-Transform Infrared Spectroscopy (FT-IR), Electrophoretic (ELS), and Dynamic Light Scattering (DLS) as well as Transmission Electron Microscope (TEM) and Scanning Electron Microscope (SEM). Their antioxidant activity was also tested using the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH). The results showed that the synthesized nanoparticles enrich the hydrogels with antioxidant properties and new surface properties (depending on the reducing agent, they can be more hydrophilic or hydrophobic). Preliminary observations indicated low cytotoxicity of the nanomaterials in both liquid form and as a hydrogel component, as well as their lack of penetration through pig skin. The cosmetic properties of hydrogel masks were also confirmed, such as increasing skin hydration. Full article

Background/Objectives: Skin injuries are common in the equine clinical practice, requiring effective treatment to support natural healing. Bacuri butter is gaining attention for its potential in wound healing and its anti-inflammatory, antimicrobial, and antioxidant properties. Natural polymers such as onion (Allium cepa) bioplastics have been investigated for their potential as occlusive dressings and for tissue regeneration. Methods: This study evaluated the healing process of experimentally induced skin wounds on horses treated with bacuri butter, washed onion film, and unwashed onion film. Clinical and histopathological analyses of the wounds were conducted in six clinically healthy horses over 28 days, with a control group receiving Ringer’s lactate solution. The onion films were produced and characterized for their chemical structure and properties, while the bacuri butter was sourced and prepared for application. Results: All treatments, including the control group, promoted wound healing without relevant differences in wound contraction rates, gross aspect, or histopathological parameters. Conclusions: Therefore, despite minor variations observed in the clinical evaluations between the treatment groups, the bacuri butter or onion biopolymer showed no significant healing effect on skin wounds in horses. Additionally, this study showed the potential of equine models in testing novel therapeutic approaches for wound healing, benefiting both veterinary and human medicine. Full article

Crop residue after harvesting onion (Allium cepa) and garlic (Allium sativum) has great potential in the development of value-added products due to the presence of a range of bioactive compounds. The potential of compounds identified in crop residue extracts to be used in cosmetics was evaluated in silico, including prediction of their interactions with selected skin target proteins (SIRT1, TGF-β, and elastase). Molecular docking results obtained using AutoDock Vina revealed that stronger binding affinity was observed between TGF-β protein and small molecules such as rutin and procyanidin A2 compared to elastase. On the other side, SIRT1 protein showed the best interaction with quercetin and kaempferol. Potential side effects on the skin of individual molecules in extracts of garlic and onion were predicted using regulated databases for skin sensitization tests (Ambit, SkinSensDB, Danish QSAR Database, and Skin Doctor CP). These in silico predictions have shown that the most active molecules are not irritating or corrosive to the skin. The obtained results indicate significant potential for the use of crop residue extracts in the development of skincare products from sustainable resources while addressing the issues of waste. Full article

This study optimized the extraction conditions to maximize the recovery yields of quercetin and total flavonoids from red onion skin waste using sequential microwave/ultrasound-assisted extraction. Five effective factors of quercetin extraction yield were investigated using response surface methodology. The method was successfully performed under optimal 60 s microwave irradiation conditions followed by 15 min sonication at 70 °C with 70% (v/v, water) ethanol with a solvent-to-solid ratio of 30 mL/g. The variance analysis of the model for both quercetin (Y₁) and total flavonoid (Y₂) recovery from DOS demonstrated that ultrasound temperature (X₂) was the most highly significant and influential factor, with a p-value of <0.0001 for both responses. Additionally, three key interaction terms—X₁X₂, X₂X₄, and X₂X₅—were identified as highly significant, further underscoring the critical role of ultrasound temperature in optimizing the extraction process for both quercetin and total flavonoids. The maximum recovery yields of quercetin and total flavonoids from red onion skin were 10.32% and 12.52%, respectively. The predicted values for quercetin (10.05%) and total flavonoids (12.72%) were very close to the experimental results. The recovery yields obtained from different extraction methods under the identical experimental conditions mentioned earlier were ultrasound/microwave-assisted extraction (7.66% quercetin and 10.18% total flavonoids), ultrasound-assisted extraction (5.36% quercetin and 8.34% total flavonoids), and microwave-assisted extraction (5.03% quercetin and 7.91% total flavonoids). The ANOVA confirmed highly significant regression models (p-values < 0.0001), with an insignificant lack of fit (p = 0.0515 for quercetin, p = 0.1276 for total flavonoids), demonstrating the robustness and reliability of the optimization. This study provides valuable insights for improving the extraction of bioactive compounds, which is critical for developing effective cancer treatments and advancing medical research. Additionally, the model shows potential for scaling up food processing applications to recover valuable products from red onion skin waste. Full article

Staphylococcus aureus is one of the leading causes of skin and soft tissue infections, and it is even life-threatening if it enters the bloodstream, lung or heart. In the present work, we proposed a novel colorimetric biosensor for the detection of S. aureus through hydrogen peroxide consumption. An onion-like carbon nanozyme with high peroxidase-like activity was prepared, which competed with the endogenous catalase of S. aureus in consuming hydrogen peroxide. This reaction was further characterized by the colorimetric reaction of 3,3′,5,5′-tetramethylbenzidine. The results showed that our approach allowed for the simple and rapid determination of S. aureus, with a linear range of 2 × 10⁴ to 2 × 10⁷ CFU/mL. Moreover, our method displayed good selectivity, with Bacillus subtilis and Escherichia coli showing negligible responses at the concentration of 2 × 10⁵ CFU/mL. The application of the as-prepared biosensor to analyze S. aureus in real water samples yielded recovery rates ranging from 95% to 112%, with relative standard deviations less than 7%. The method demonstrated good accuracy and specificity, which offers a novel approach for the simple and selective detection of S. aureus. Full article

Quercetin, a bioactive plant flavonoid, is an antioxidant, and as such it exhibits numerous beneficial properties including anti-inflammatory, antiallergic, antibacterial and antiviral activity. It occurs naturally in fruit and vegetables such as apples, blueberries, cranberries, lettuce, and is present in plant waste such as onion peel or grape pomace which constitute good sources of quercetin for technological or pharmaceutical purposes. The presented study focuses on the role of quercetin in prevention and treatment of dermatological diseases analyzing its effect at a molecular level, its signal transduction and metabolism. Presented aspects of quercetin potential for skin treatment include protection against aging and UV radiation, stimulation of wound healing, reduction in melanogenesis, and prevention of skin oxidation. The article discusses quercetin sources (plant waste products included), methods of its medical administration, and perspectives for its further use in dermatology and diet therapy. Full article

Quercetin (QR-3,3′,4′,5,7-pentahydroxylflavone) is very well known as a strong antioxidant with anti-inflammatory, antiviral, antineoplastic, and antithrombotic properties that can act as a free radical scavenger in human beings. It can be found in vegetables such as capers, lovage, broccoli, lettuce, spinach, onions, tea, seeds, and fruit skins. QR is recognized as one of the most important nutrients in a person’s daily diet. Lipoic acid (LA), also known as 1,2-dithiolane-3-pentanoic acid, is synthesized by animal, plant, and human cells from fatty acids and cysteine. LA is often used in the treatment of oxidative stress, diabetes, cardiovascular and hepatitis diseases, and heavy metal poisoning. In the literature, several chromatographic and optical methods have been developed in order to determine the presence of lipoic acid and quercetin with a low detection limit, but these methods have drawbacks such as sample pretreatments, the use of hazardous and expansive chemicals, and sophisticated extraction procedures. In view of this, an alternate electrochemical method for the sensitive determination of LA and QR is required. In the present work, we have developed novel electrochemical platforms for LA and QR sensing based on PEDOT-PB (poly(3,4-ethylenedioxythiophene-Prussian Blue) and PEDOT-AgNPs. Both nanocomposite materials were synthesized using a sinusoidal currents (SCs) method. The amplitude and frequency of the SCs method have been optimized. The developed electrochemical sensing platforms that use PEDOT-PB and PEDOT-AgNPs were assessed and validated for their LA and QR determination in synthetic and real samples in terms of their limit of detection, limit of quantification, and linear response range. The proposed sensing platforms ensured a comparable, fast, simple, and reliable detection of the target analytes QR and LA without sample pretreatment, as is usually required by other analytical methodologies such as chromatographic and optical methods. Full article

Onion skin waste (OSW), the primary non-edible byproduct from onion processing, offers a renewable source of bioactive compounds. This study aims to valorize OSW through subcritical water extraction (SWE), aligning with a circular economy and biorefinery principles. SWE was carried out at 145 °C and 50 bar for 50 min in a discontinuous reactor, producing a phenolic-rich extract (32.3 ± 2.6 mg/g) dominated by protocatechuic acid (20.3 ± 2.5 mg/g), quercetin-4′-O-glucoside (7.5 ± 0.2 mg/g), and quercetin (3.2 ± 0.6 mg/g). Additionally, the extract contains sugars (207.1 ± 20.3 mg sucrose-Eq/g), proteins (22.8 ± 1.6 mg BSA-Eq/g), and free amino acids (20.4 ± 1.2 mg arginine-Eq/g). Its phenolic richness determines its scavenging activity against ^●NO and O₂^●− radicals and its α-glucosidase and aldose-reductase inhibition without affecting α-amylase. Notably, the extract demonstrates significant α-glucosidase inhibition (IC₅₀ = 75.6 ± 43.5 µg/mL), surpassing acarbose (IC₅₀ = 129.5 ± 1.0 µg/mL) in both pure enzyme and cell culture tests without showing cytotoxicity to AGS, HepG2, and Caco-2 human cell lines. The extract’s bioactivity and nutritional content make it suitable for developing antioxidant and antidiabetic nutraceutical/food components, highlighting SWE’s potential for OSW valorization without using organic solvents. Full article

Onion waste, particularly onion skin, is a widely generated waste material, and harnessing its potential for energy storage aligns with sustainable development goals. Despite the high specific surface area exhibited by biocarbon derived from onion skin, its Li-ion storage performance is not desirable. In this study, biocarbon derived from purple onion skin serves as the substrate for accommodating cobalt oxide (Co₃O₄) through a hydrothermal method, employing Co(NO₃)₂·6H₂O at various concentrations, and with and without prior activation using KOH treatment. The resulting samples undergo comprehensive analyses, including phase, morphological, surface, and electrochemical characterizations. The Co₃O₄ decoration on activated carbon derived from onion skin, synthesized using Co(NO₃)₂·6H₂O at a concentration of 1 M, reveals a porous structure with a surface area of 702 m²/g, featuring predominant pore sizes of less than 5 nm. Significantly, the Li-ion storage performance of this sample surpasses that of alternative samples, demonstrating a remarkable reversible capacity of 451 mAh/g even after 500 cycles at an elevated current density of 2000 mAh/g. The charge transfer resistance of the sample (110.3 Ω) is found to be substantially lower than that of the sample prepared using carbonized onion skin biomass without activation. This research introduces an innovative approach leveraging onion skin waste as a template for Co₃O₄ decoration, thereby fabricating high-performance anodes for lithium-ion batteries. Full article

From a sustainability and circular economy point of view, this study evaluated the possibility of recovering antioxidant compounds from Rossa di Tropea onion waste for application in the food industry as natural ingredients. In particular, the aim was to investigate the effect of adding natural antioxidants recovered from ‘Rossa di Tropea’ onion waste to maintain/improve the functional and qualitative characteristics of white bread. Total phenolic content, antioxidant activity, and sensorial aspects were studied on the different enriched samples during the storage period. The ‘Rossa di Tropea’ onion skins proved to be a good source of natural polyphenols, and their use in white bread production has resulted in a significant increase in bioactive compound content and antioxidant activity (ABTS and DPPH assays). Moreover, the enriched bread showed acceptable quality attributes in terms of odor, colour, and taste, despite the increase in firmness during the storage time compared to the control sample. The obtained results suggest the possibility of applying the antioxidants recovered by ‘Rossa di Tropea’ onion waste as ingredients in the formulation of bakery products to obtain new food with functional characteristics. Full article

This paper describes experimental studies of cutting the outer layer of onions in a machine processing process. For this purpose, an original, globally innovative machine design with a modular structure was used, which was constructed in a real scale. For the purposes of carrying out the experimental studies, a test stand was constructed, a plan and programme for the studies were adopted, and a research methodology was developed. The results gained and the data obtained from the equations of the regression function for the developed machine design were used to construct systems of independent variables for which the dependent variable reaches extreme values. The unit energy consumption of the onion peeling process increases together with an increase in the number of air nozzles and the air pressure supplying the unit for removing the skins, while an increase in the material feeding speed and in the distance of the air nozzles results in a decrease in the energy consumption of the process. Full article

The growing concern regarding the adverse effects of synthetic UV filters found in sunscreens has spurred significant attention due to their potential harm to aquatic ecosystems and human health. To address this, the present study aimed to extract and microencapsulate sensitive bioactive compounds derived from by-product onion peel (OP) by molecular inclusion using β-cyclodextrin as the wall material. Identification and quantification of bioactive compounds within the extract were conducted through high-performance liquid chromatography (HPLC-DAD) analysis, revealing quercetin and resveratrol as the primary constituents. The photoprotection capacity, evaluated by the sun protection factor (SPF), revealed a protection factor comparable to the value for a synthetic UV filter. The produced microparticles presented high antioxidant capacity, significant photoprotection capacity, encapsulation efficiency of 91.8%, mean diameter of 31 μm, and polydispersity of 2.09. Furthermore, to comprehensively evaluate the performance of OP extract and its potential as a natural UV filter, five O/W emulsions were produced. Results demonstrated that microparticles displayed superior ability in maintaining SPF values over a five-week period. Photoprotection evaluation–skin reactivity tests revealed that both extract and microparticles absorb UV radiation in other regions of UV radiation, revealing their potential to be used as a natural UV filter to produce a sustainable and eco-friendly value-added sunscreen. Full article