Search Results (67)

This study presents the results obtained from extracting and quantifying cosmetically valuable metabolites such as phenolic compounds and mycosporine-like amino acids (MAAs) from 12 samples of marine macroalgae collected in the Colombian Caribbean Sea. Natural deep eutectic solvents (NADESs) were prepared, physicochemically tested (viscosity, surface tension, pH, and conductivity), and then compared with water as the reference solvent to quantify phenolic compounds using the Folin–Ciocalteau test. With a simple extraction assay with water and ultrasound followed by ultraviolet spectral scanning the presence of MAAs was easily determined in several of the analysed samples, and then they were identified by HPLC-DAD. Hydrochloric acid solution at 5% extracted a higher content of phenolic compounds than NADES and water. The NADES that showed the highest phenolic compound extraction yield was a mixture of betaine, glucose, and water with 1:1:5 molar ratio. Sargassum cf. ramifolium and Sargassum fluitans showed the highest contents of phenolic compounds extracted with NADES, with 29.2 and 21.9 mg GAE/g DW, respectively. The results show that NADESs are an interesting alternative for the more efficient extraction of cosmetically valuable compounds such as phenolic compounds and mycosporine-type amino acids from marine macroalgae. Full article

Honey has been used for centuries for its antibacterial and healing properties. The aim of this study was to investigate the antibacterial properties, arabinogalactan proteins (AGPs), antioxidant activities, and polyphenolic content of eight different types of New Zealand honey (clover, mānuka, beech honeydew, pōhutukawa, kānuka, rewarewa, kāmahi and thyme honey). The results showed varying antibacterial activities across the honey types, with mānuka, pōhutukawa, and kāmahi honey exhibiting significant inhibitory effects. Interestingly, all honey samples demonstrated inhibitory effects on bacterial growth at 25% concentration. Furthermore, AGPs were found in all eight honey samples, with higher amounts in kānuka, kāmahi, pōhutukawa, mānuka, and rewarewa honey. Thyme had the highest antioxidant values in terms of CUPRAC, FRAP and DPPH, while kāmahi honey had the lowest antioxidant value. Beech honeydew honey had the highest Total Flavonoid Content (TFC) values, while thyme and clover honey had the lowest TFC values. Similarly, thyme honey exhibited the highest Total Phenolic Content (TPC) value, with kāmahi and clover honey having the lowest TPC values. Furthermore, only thyme and beech honeydew New Zealand honeys contained vitamin C. The different honeys contained varying concentrations of polyphenols, with mānuka, kānuka, and pōhutukawa honeys having high amounts of quercetin, luteolin, and gallic acid, respectively. In contrast, clover honey had notable levels of chrysin, pinocembrin, caffeic acid, and pinobanksin. Overall, this study provides valuable insights into the antibacterial properties and bioactivities of native New Zealand honeys, contributing to our understanding of the potential health benefits associated with these honeys and their potential use as natural alternatives to improve human health. Full article

Fungal endophytes of medicinal plants produce diverse secondary metabolites and extracellular enzymes with therapeutic and biotechnological potential. However, the biological and biotechnological potential of fungal endophytes from South African medicinal plants remain relatively underexplored. In this study, the antimicrobial, antioxidant, anti-inflammatory and extracellular enzymatic capabilities of five fungal endophytes previously isolated from the leaves of Kirkia acuminata Oliv. were investigated. Sequencing of the internal transcribed spacer (ITS) regions revealed that the isolates belonged to the genera Setosphaeria, Diaporthe and Corynespora. The broth micro-dilution assay and the Folin–Ciocalteau reagent method were used to assess the antibacterial activity and the total phenolic content (TPC) of the fungal endophytes’ ethyl acetate crude extracts (CEs), respectively. The antioxidant activity was assessed using the ferric reducing antioxidant power (FRAP) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assays. The influence of the CE of the Setosphaeria rostrata KaL-4 on the viability and LPS-induced interleukin-6 (IL-6) production in Raw 264.7 macrophages was assessed using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and an ELISA, respectively. The ability of the isolates to produce extracellular proteases, laccases and peroxidases was also determined. The CEs displayed antimicrobial activity with MICs ranging from 0.63 to 1.25 mg/mL and reducing power and scavenging activity ranging from 40% to 18% and from 60% to 48%, respectively. The S. rostrata KaL-4 CE possessed the highest TPC and demonstrated dose-dependent cytotoxicity. The CE further demonstrated a significant reduction in IL-6 production at a concentration of 0.75 µg/mL. Only one isolate demonstrated the ability to produce proteases with an enzymatic index (EI) of 0.66, while laccases (EI range of 0.14 to 1.15) and peroxidases were produced by all of the isolates. These findings suggest that fungal endophytes from South African medicinal plants are promising sources of bioactive compounds and industry-significant extracellular enzymes. Full article

Bioactive compounds and organic acids are applied to a wide range of foods against different types of foodborne pathogens. In the present study, carvacrol and thymol (1000 mg/L) were applied in wine-based marinades, alone or in combination with them and in combination with tartaric acid, malic acid, ascorbic acid, citric acid, and acetic acid (in concentration 0.1% w/v), in chicken and beef fillets and their antimicrobial activity, antioxidant capacity, and pH were estimated during refrigerated storage. Likewise, their antimicrobial activity was recorded against Enterobacteriaceae, total mesophilic bacteria, yeasts/molds, and lactic acid bacteria. The outcome demonstrated that both meats kept under similar storage conditions (4 °C/9 days) exhibited lower microbial growth, particularly with Enterobacteriaceae, when treated with wine-based carvacrol—thymol marinades and may extend their shelf-life. This antimicrobial action was more pronounced in the beef samples. The total phenolic content (TPC) and the antioxidant activity of the applied marinades were determined using the Folin−Ciocalteau method and ABTS and DPPH radical scavenging activity methods, respectively. The results revealed that marinades with thymol and/or carvacrol in combination with acetic or ascorbic acid had greater TPC and antioxidant activity. The pH values of the respective marinades applied to both chicken and beef fillets exhibited an upturn during storage. Consequently, these marinades, even at low concentrations, could be used as natural preservatives in meat products. Full article

There is an increased demand for healthy foods by the consumer nowadays, while at the same time, circular bio-economy and sustainability in food production represent top priority issues for the food industry. In this context, purslane, a highly nutritious annual plant that grows abundant during the hottest months of the year but is considered a by-product of the agricultural process, was utilized for the development of an innovative, ready-to-eat food product suitable for a vegetarian diet in the form of a bread spread. Following an initial small-scale experimentation for the stabilization of apparent quality attributes, the product’s recipe was finalized on an industrial scale, and the hazard analysis and critical control point (HACCP) for the manufacturing process, the physicochemical (pH, water activity) and sensorial analysis of the end product, together with its nutritional value, shelf-life, and antioxidant capacity, were determined. The results suggested that the acidic (pH 4.3) product had a shelf-life of a minimum of six months to one year and, according to EU legislation, it comprised a source of (dietary) fibers and protein, while being high in poly-unsaturated (e.g., omega-3, omega-6), and mono-unsaturated (e.g., oleic acid) fatty acids. Total phenolic content (TPC) with the Folin–Ciocalteau assay and total antioxidant capacity (TAC) using the Ferric-Reducing Antioxidant Power assay of the product, presented concentrations of 0.95 mg of gallic acid equivalent/g and 0.016 mmol of Fe²⁺/g of dry weight of sample, respectively. However, the predicted bioavailability for TPC and TAC was 28% and 31%, respectively. The product was evaluated positively by a panel of potential consumers without significant differences compared to conventional familiar products. The potential of using agro-food chain by-products, such as purslane, for the development of novel foods representing a healthy and tasty food choice at any time of the day is a promising opportunity for the food industry to meet growing consumer demands for more sustainable, nutritious, and healthy food products with a reduced environmental footprint compared to the traditional plant-originated products of intensive agriculture. Full article

Honey is traditionally used for its medicinal properties attributed to its antibacterial and antioxidant effects. It is considered a natural alternative to conventional antibiotics. This effect has been attributed to their physico-chemical properties, as various chemical parameters can synergistically influence this effect. The aim of this study is to assess Spanish honeys of diverse botanical origins for their antibacterial efficacy against Staphylococcus epidermidis, correlating their physico-chemical attributes, (poly)phenol content, and antioxidant activity. The methods included colour determination via two methodologies, acidity, pH, moisture content, and sugar concentration. (Poly)phenol content was quantified using the Folin-Ciocalteau method, while antioxidant activity was evaluated via the FRAP method. Subsequently, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against S. epidermidis were investigated with different concentrations of honeys. The results revealed a direct relationship between honey darkness, (poly)phenol concentration, antioxidant activity, and antibacterial efficacy. Darker honeys exhibited higher (poly)phenol levels, greater antioxidant activity, and consequently, lower MIC and MBC values, showing enhanced antibacterial properties. These findings underscore the potential of honey as a therapeutic agent against S. epidermidis, particularly in wound healing applications to avoid infection. Further research into honey’s multifaceted properties is warranted to unveil novel therapeutic avenues in healthcare. Full article

The present study explores the efficiency of selenomethionine (Semeth), an organic form of Se, as an antioxidant compared with commonly used antioxidants (ascorbic acid, glutathione, and potassium metabisulfite) in preventing oxidative browning in Greek white wines (Malagouzia and Retsina). The experimental procedure involved an accelerated browning test conducted over 12 days at 55 °C, measurement of antioxidant activity values (using the Folin—Ciocalteau and the free radical diphenylpicrylhydrazyl (DPPH) methods), determination of free sulfhydryl groups using the Ellman’s method, and High-Performance Liquid Chromatographic analysis of selected phenolic compounds. Semeth consistently exhibited a preserving effect on total and free SO₂ content and antioxidant activity values of Malagouzia wines. Semeth also showed a protecting effect on free sulfhydryl groups (-SH), even higher than that of SO₂ suggesting that its role in maintaining wine color involves more mechanisms than just the prevention of SO₂ reduction. Moreover, Semeth demonstrated promising effects in preserving individual phenolic content, in particular (+)-catechin and fertaric acid, compared to the other antioxidant additions. Both browning rate constants and percentage color change values of Retsina where higher than the corresponding values of Malagouzia wines indicating greater susceptibility to browning. Browning development was dependent on the particular antioxidant added, with ascorbic acid being the least effective. The results of this study suggest that Semeth could be an important candidate for enhancing the oxidative stability of white wines, offering at the same time valuable information for optimizing antioxidant strategies in winemaking practices. Full article

Phytochemical screening of four commercial products containing Salvia officinalis was carried out. Total phenolic content was estimated spectrophotometrically through the use of the Folin–Ciocalteau method, flavonoid content was measured through the use of aluminum chloride and 2,4-dinitrophenylhydrazine colorimetric assays, and isoflavones and α/β-thujones were analyzed through the use of high-performance liquid chromatograph (HPLC) and the gas chromatographic method. The analyses revealed the absence of thujones and isoflavones (i.e., genistin, genistein, and daidzein) in all four different extracts. The content of polyphenolic compounds varied among the samples, with the extract T being richer in both polyphenols and flavonoids than the other products by 1.8–3.2 and 1.4–4.0 times, respectively (p-value < 0.05). These results highlight the importance of quality control in salvia-based products since a thujone-free extract rich in polyphenols and flavonoids could be a good candidate for further preclinical and clinical studies to identify an effective herbal approach suitable for the long-term therapy of menopausal symptoms. Full article

Yerba mate consumption has been stimulated by scientific discoveries that have identified high concentrations of bioactive compounds and their health benefits. We were interested in quantifying caffeine, theobromine, total phenolic compounds and protein concentrations in yerba mate genotypes and their stability over four years on the same plants. Mature leaves from adult yerba mate genotypes selected on a provenance and progenies trial were collected in August of 2015, 2016, 2017 and 2018. Methylxanthines (caffeine and theobromine) were quantified by High-Performance Liquid Chromatography (HPLC), total phenolic compounds by Folin–Ciocalteau spectrophotometric method and total protein analysis by the micro-Kjeldahl method. Genotype stability was analyzed through the AMMI (Additive Main effects and Multiplicative Interaction) procedure. Our results indicate large variations between genotypes regarding caffeine (0.035 to 2.385 g 100 g⁻¹), theobromine (0.0004 to 1.772 g 100 g⁻¹), total phenolic compounds (7.028 to 9.424 g 100 g⁻¹), proteins (10.39 to 16.58 g 100 g⁻¹) contents and the high stability of those compounds over the four evaluated years, on the same plants. This information, combined with the stability of bioactive compounds, establishes a significant potential for innovation within the Ilex paraguariensis species. Full article

Knowledge of the physicochemical characteristics of organic moringa leaves, such as the color, the moisture control and water activity (aw) for biological control, as its basic composition, provides valuable starting data for its improvement and quality control through the selection of key parameters for the conservation of its multiple nutritional and antioxidant qualities in organic production systems adapted to local conditions. Objective: Describe the physicochemical characteristics and composition of macro- and micronutrients of Moringa oleifera leaves from a vivarium under controlled conditions and evaluate the antioxidant potential of dried moringa leaves from organic production in Paraguay under experimental conditions. A systematic sampling of moringa leaves from a vivarium was carried out. For color analysis, the CIEL*a*b* coordinates were determined. For physicochemical characteristics’ analysis and macro- and micronutrient composition, official methods were used, while Total Phenolics Compounds (TPC) were determined by the Folin Ciocalteau method, and the Total Antioxidant Capacity (TAC) was determined by the antioxidant inhibition test (Radical ABTS+). Under experimental conditions, the dried moringa leaves under experimental conditions presented a light green color and low levels of humidity (8.1 ± 0.4%) and a_w (0.59), with high protein levels (27%), micronutrients such as minerals (Ca, Mg, P, Fe, Zn), vitamins B1, B2, Vit. C, TPC (5051 ± 168 g GAE/100 g) and antioxidants (468 ± 109 mMTEAC/g). Moringa leaves from Paraguay represent a source of micronutrients in the diet, and can be applied as ingredients in different culinary preparations within the framework of a healthy and sustainable diet, in accordance with the Sustainable Development Goals (SDGs). Full article

Nowadays, there is a high demand in many industrial countries for healthy foods and sustainable products and so to explore innovative food technologies, such as fortification with bioactive compounds such as antioxidants and polyphenols, that may be sourced from herbs or by-products. This study’s objective was to explore the fortification of refined olive oils with natural bioactive compounds such as the herbs rosemary (Rosmarinus officinallis, L.), basil (Ocimum basillicum, L.), sage (Salvia officinalis, L.), lemon balm (Melissa oficinallis, L.), St. John’s wort (Hypericum perforatum, L.), pink savory (Satureja thymbra, L.), dittany (Origanum dictamnus, L.), and by-products such as pomace from olives, olive leaves (Olea europaea, L.), orange peel (Citrus aurantium, L.), lemon peel (Citrus limon, L.), pomegranate peel (Punica granatum, L.), and mandarin peel (Citrus reticulata). The fortification of the refined olive oils was performed with the use of different methodologies such as conventional maceration (CM), incubation shaking maceration (ISM), and ultrasound-assisted maceration (UAM). Folin–Ciocalteau (FOLIN) and Ferric-Reducing Antioxidant Power (FRAP) assays were used to measure their total phenolic content and antioxidant capacity. All methods demonstrated that the temperature, sample concentration, and time of maceration are considered of high importance in the fortification of refined olive oil. In vitro digestion process showed the bioavailability of the antioxidant and phenolic compounds in the fortified olive oil that ranged from 4.84% to 53.11%. Furthermore, the refined olive oils fortified with pomace, basil, St. John’s wort, and pomegranate peel presented the highest antioxidant and phenolic predicted bioavailability indices during the in vitro process compared to the control refined olive oil. Finally, fortification with natural herbs or by-products can be considered an innovative method for the enhancement of the nutritional value of refined olive oils. Full article

In the last decades, Primula veris subsp. veris (roots and flowers) has been over harvested through legal and illegal ways in Greece, due to its extremely high commercial demand, as it is used in industry because of its well-known therapeutic properties. As ex situ cultures of the plant have been already developed, in the current comparative study, the herbal teas (infusions) from both flowers of cowslip growing wild in the Prespa Lake Park (NW Greece), and from ex situ propagated and cultivated plant material, have been investigated, with the ultimate goal of assessing them qualitatively. Furthermore, through classic phytochemical studies, the ten most abundant metabolites, belonging to the chemical categories of flavonol-glycosides and methoxy flavones, have been identified and structurally determined. The chemical profile of both infusions has been further analyzed through UHPLC-HRMS, showing that they show only light differences. The total phenolic content (TPC) of both studied samples (wild and ex situ cultivation), was determined by the Folin–Ciocalteau method, followed by an antioxidant activity assay though DPPH where, in both cases, wild plants exerted higher phenolic load and stronger antioxidative properties. According to the reported results, it could be proposed that the ex situ cultivated plant material could facilitate the mass production of plants and the sustainable cultivation of cowslip in the Greek mountains. Full article

Rosmarinus officinalis or Rosemary is a highly valued medicinal vegetal, owing to its notable antispasmodic, anti-inflammatory, and antibacterial properties. In the current work, we aimed to identify the chemical components of the essential oil (EO) of R. officinalis and evaluate its biological properties using an in vitro approach. High performance liquid chromatography time-of-flight mass spectrometry (HPLC-TOF-MS) was utilized to analyze of the hydro-methanolic extract (HME), while gas chromatography–mass spectrometry (GC/MS) was considered during the analysis of the EO’s chemical composition. The antioxidant abilities of HME and the EO were assessed using diverse tests (DPPH, ABTS, GOR, CUPRAC, and FRAP). The anti-enzymatic properties were tested by the inhibition of cholinesterases, α-glucosidase, and tyrosinase enzyme. The HPLC-TOF-MS displayed the existence of flavonoids like luteolin glucuronide I and II, and a few known hydroxycinnamic acids. The EO contained three major components, namely, eucalyptol (28.7%), camphor (16.7%), and borneol (13.5%). The HME had a high total polyphenol content, as determined by the Folin–Ciocalteau method (335.37 ± 9.33 µg of gallic acid eq·mg⁻¹). Notably, the analysis of the bioactivities of the HME and EO revealed comparatively that they possessed higher radical scavenging capacity in the DPPH, ABTS, and galvinoxyl assays, while EO exhibited a higher capacity for enzyme inhibition. Overall, our findings suggest that both the EO and HME extract of Algerian’s R. officinalis holds great usefulness in the pharmaceutical and nutraceutical fields due to its elevated polyphenol content and potent bioactivities. Full article

Potentilla nepalensis Hook is a perennial Himalayan medicinal herb of the Rosaceae family. The present study aimed to evaluate biological activities such as the antioxidant, antibacterial, and anticancer activities of roots and shoots of P. nepalensis and its synergistic antibacterial activity with antibacterial drugs. Folin–Ciocalteau and aluminium chloride methods were used for the calculation of total phenolic (TPC) and flavonoid content (TFC). A DPPH radical scavenging assay and broth dilution method were used for the determination of the antioxidant and antibacterial activity of the root and shoot extracts of P. nepalensis. Cytotoxic activity was determined using a colorimetric MTT assay. Further, phytochemical characterization of the root and shoot extracts was performed using the Gas chromatography–mass spectrophotometry (GC-MS) method. The TPC and TFC were found to be higher in the methanolic root extract of P. nepalensis. The methanolic shoot extract of P. nepalensis showed good antioxidant activity, while then-hexane root extract of P. nepalensis showed strong cytotoxic activity against tested SK-MEL-28 cells. Subsequently, in silico molecular docking studies of the identified bioactive compounds predicted potential anticancer properties. This study can lead to the production of new herbal medicines for various diseases employing P. nepalensis, leading to the creation of new medications. Full article

Black poplar buds have high contents of many compounds with therapeutic potential, which are useful in cosmetics and the treatment of various dermatitis, respiratory diseases, etc. The aim of this study was to identify and exploit the local plant resources with biologically active properties from the Dobrogea area, Romania. For this purpose, materials were collected from the mentioned area, and macerates of black poplar were prepared in order to evaluate their qualities as antioxidant and antimicrobial agents. Three different black poplar buds’ hydroalcoholic macerates were analyzed by the Folin–Ciocâlteau method to estimate the total content of phenolic compounds, by the HPLC-DAD method for identification and quantification of the main bioactive compounds and by the DPPH radical scavenging method to evaluate the antioxidant activity. All hydroalcoholic macerates showed high concentrations of phenolic compounds, the main individual compounds being gallic acid, chlorogenic acid, cinnamic acid, and methyl gallic acid. The antioxidant activity of the black poplar buds’ hydroalcoholic macerates, evaluated by the DPPH radical scavenging test, showed high values, between 496 and 1200 mg GAE /100 g d.w. The Cd, Cu, Zn, Ni, and Pb concentrations released in dry poplar buds, determined by AAS, were below the detection limits. Hydroalcoholic macerates of black poplar were tested against two groups of gram-positive bacteria (Enterococcus and Staphylococcus) using an agar well diffusion assay. The in vitro inhibitory activities of the macerates were important and ranged from 8.2–9.4 mm inhibition zones (Staphylococcus) to 8.6 −10 mm inhibition zones (Enterococcus). Full article