Search Results (23)

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

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

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

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

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

When the total phenolic content (TPC) and antioxidant activity of sea buckthorn juice were assayed by spectrophotometry, the reaction solutions were not clarified, so centrifugation or membrane treatment was needed before determination. In order to find a suitable method for determining TPC and antioxidant activity, the effects of centrifugation and nylon membrane treatment on the determination of TPC and antioxidant activity in sea buckthorn juice were studied. TPC was determined by the Folin-Ciocalteau method, and antioxidant activity was determined by DPPH, ABTS, and FRAP assays. For Treatment Method (C): the sample was centrifuged for 10 min at 10,000 rpm and the supernatant was taken for analysis. Method (CF): The sample was centrifuged for 10 min at 4000 rpm, filtered by Nylon 66 filtration membranes with pore size of 0.22 μm, and taken for analysis. Method (F): the sample was filtered by Nylon 66 filtration membranes with pore size of 0.22 μm and taken for analysis. Method (N): after the sample of ultrasonic extract solution reacted completely with the assay system, the reaction solution was filtered by Nylon 66 filtration membranes with pore size of 0.22 μm and colorimetric determination was performed. The results showed that centrifugation or transmembrane treatment could affect the determination of TPC and antioxidant activity of sea buckthorn juice. There was no significant difference (p > 0.05) between methods (CF) and (F), while there was a significant difference (p < 0.05) between methods (C) (F) (N) or (C) (CF) (N). The TPC and antioxidant activity of sea buckthorn juice determined by the four treatment methods showed the same trend with fermentation time, and the TPC and antioxidant activity showed a significant positive correlation (p < 0.05). The highest TPC or antioxidant activity measured by method (N) indicates that method (N) has the least loss of TPC or antioxidant activity, and it is recommended for sample assays. Full article

Oxidative damages are responsible for many adverse health effects and food deterioration. The use of antioxidant substances is well renowned, and as such, much emphasis is placed on their use. Since synthetic antioxidants exhibit potential adverse effects, plant-derived antioxidants are a preferable solution. Despite the myriads of plants that exist and the fact that numerous studies have been carried out so far, there are many species that have not been examined so far. Many plants under research exist in Greece. Trying to fill this research gap, the total phenolics content and antioxidant activity of seventy methanolic extracts from parts of Greek plants were evaluated. The total phenolics content was measured by the Folin–Ciocalteau assay. Their antioxidant capacity was calculated by the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) scavenging test, the Rancimat method based on conductometric measurements, and the thermoanalytical method DSC (Differential Scanning Calorimetry). The tested samples were obtained from several parts of fifty-seven Greek plant species belonging to twenty-three different families. Both a remarkably high phenolic content (with gallic acid equivalents varying between 311.6 and 735.5 mg/g of extract) and radical scavenging activity (IC₅₀ values ranged from 7.2 to 39.0 μg/mL) were found in the extract of the aerial parts of Cistus species (C. creticus subsp. creticus, C. creticus subsp. eriocephalus, C. monspeliensis, C. parviflorus and C. salviifolius), Cytinus taxa (C. hypocistis subsp. hypocistis, C. hypocistis subsp. orientalis and C. ruber), and Sarcopoterium spinosum. Furthermore, the sample of Cytinus ruber showed the highest protection factor (PF = 1.276) regarding the Rancimat method, which was similar to that of butylated hydroxytoluene (BHT) (PF = 1.320). The results indicated that these plants are rich in antioxidant compounds, potentiating their use either as food additives to enhance the antioxidant properties of food products, or protect them from oxidation, or as sources for the preparation of food supplements with antioxidant properties. Full article

Exhausted olive pomace (EOP) is a waste generated in large quantities each year in the olive oil industry. This biomass contains phenolic compounds with antioxidant, antiatherogenic, anti-inflammatory, and antimicrobial properties. For the extraction of these compounds, the use of a novel and environmentally friendly technique, microwave-assisted extraction using water as extraction solvent, was proposed. A Box–Behnken design of experiments based on the response surface methodology was used to optimise the effect of the factors temperature (40–100 °C), extraction time (4–40 min), and solid loading (2–15%). The response variables were the total phenolic content analysed by Folin–Ciocalteau assay, hydroxytyrosol content by HPLC, and antioxidant activity through FRAP and ABTS assays. The optimal conditions for each response variable were determined. Overall, microwave-assisted extraction is considered a suitable technique for the extraction of bioactive compounds from EOP at short extraction times. In particular, the maximum content of hydroxytyrosol (6 mg/g of EOP) could be obtained at 99.7 °C, 3.9% (w/v) solids, and 34.3 min. Therefore, this extract has the potential to be used as a functional and antioxidant additive. Full article

The purpose of this work was to evaluate the total phenol content and antioxidant activity of different types of handcrafted beers (Ego, Alter, Fiat Lux, Triplo Malto, Ubi, and Maior), as well as the starting materials (malts, hops, and yeast), the intermediate products, and the waste products (spent malts, hops, and yeast), in view of their use in innovative cosmetic formulations. Extractions from starting and spent samples were taken from water or 70° alcohol. The total phenol content (Folin Ciocalteau Essay) of all the brewing products depended on the specific product under investigation. The highest values were found in starting hops (ranging from approximately 93 to 155 mg GAE/g, according to the extraction solvent), intermediate ones in starting malt and starting yeast, and the lowest values in wort. The total phenol content in the final beers originates from the phenols that were extracted from the different ingredients, namely the starting malts, hops and yeast, but non-negligible values were still observed in spent products. The method used for the evaluation of the antioxidant activity, trolox equivalent antioxidant capacity (DPPH), ferric-ion reducing antioxidant parameter (FRAP), and radical cation scavenging activity and reducing power (ABTS) strongly influenced the results. In general, the results reflected the trend observed for the total phenol content: that beers are progressively enriched by phenols originating from all the starting ingredients, and that spent products still possess non-negligible antioxidant activity. It is interesting to note that waste yeast frequently showed higher values than those of the starting material; it can be inferred that yeast is able to absorb phenols from the beer during brewing. By considering the interest in exploiting waste derived from processing foods, the biological activity of waste Alter brewery products has been evaluated on a cell culture of keratinocytes (spent products of malt, hop, and yeast). Preliminary in vitro assays in keratinocyte HaCaT cells were carried out to assess the potential bioactivity of spent extracts. Among the spent extracts, the spent hop and yeast extracts showed the ability to improve the mitochondrial activity and prevent oxidative stress in HaCaT cells, two features in skin ageing. In conclusion, this study offers evidence that waste from handcrafted beers can be an interesting source of phenols for the preparation of skin anti-aging cosmetics. Full article

The antioxidant activity (AA), total phenolic content (TPC), and total flavonoid content (TFC) of selected Indonesian Zingiberaceae herbs were determined. An optimization extraction procedure was conducted by using Taguchi L₁₆ orthogonal array. Four chemical assays were applied, including 2,2-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity assay, H₂O₂ scavenging activity assay, Folin–Ciocalteau (F–C) assay, and NaNO₂-AlCl₃-NaOH assay, which revealed remarkable differences in AA, TPC, and TFC. The result indicated the diversity of AA composition among the herbs, and C. longa exhibited the highest AA. HPLC-PAD analysis revealed that curcumin was present in five high antioxidant herbs, and the highest amount was in C. longa. Pearson correlation analysis indicated that the identified TPC and TFC were significant contributors to AA, and curcumin was likely the main contributing antioxidant compound. Our approach concluded that C. longa is the greatest source of natural antioxidants among 12 Indonesian indigenous Zingiberaceae herbs. The use of a mixed-method approach to augment the findings of solitary methods might facilitate future researchers to uncover deeper and hidden meanings. Full article

This study aims to evaluate the effects of different drying methods on the physical properties, total phenolic content, total flavonoid content, and antioxidant activity of extracts from Moringa oliefera L. (MO) leaf waste. The effects of two drying techniques, namely, sun drying (A1) and tray drying (A2), on the physical and antioxidant properties of the extracts obtained using three extracting solvents, i.e., water (b1), ethanol (b2), and ethyl acetate (b3), were investigated. These extracts were analyzed for their physicochemical and antioxidant properties. The antioxidant properties were determined with the Folin Ciocalteau, aluminum chloride, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays. Fourier transform infrared spectrophotometry (FTIR) was used to identify functional groups in the active compounds. It was found that the physical properties of the MO extract, including yield, pH, total solids, and color, showed significant differences for the two drying methods (p < 0.05). The b3 extract had the highest value for total phenolic contents, total flavonoid contents, and antioxidant activities, followed by b2 and b1, respectively, for both the sun drying and tray drying methods. There was a significant correlation between the total phenolic and flavonoid contents and antioxidant activity (IC₅₀). This study reveals that waste material from MO leaves could be utilized as an antioxidant agent, which is expected to reduce environmental pollution from the MO processing industry. Full article

The health advantages of extra-virgin olive oil (EVOO) are ascribed mainly to the antioxidant ability of the phenolic compounds. Secoiridoids, hydroxytyrosol, tyrosol, phenolic acid, and flavones, are the main nutraceutical substances of EVOO. Applications of beneficial microbes and/or their metabolites impact the plant metabolome. In this study the effects of application of selected Trichoderma strains or their effectors (secondary metabolites) on the phenolic compounds content and antioxidant potential of the EVOOs have been evaluated. For this purpose, Trichoderma virens (strain GV41) and Trichoderma harzianum (strain T22), well-known biocontrol agents, and two their metabolites harzianic acid (HA) and 6-pentyl-α-pyrone (6PP) were been used to treat plants of Olea europaea var. Leccino and var. Carolea. Then the nutraceutical potential of EVOO was evaluated. Total phenolic content was estimated by Folin–Ciocalteau’s assay, metabolic profile by High-Resolution Mass spectroscopy (HRMS-Orbitrap), and antioxidant activity by DPPH and ABTS assays. Our results showed that in the cultivation of the olive tree, T22 and its metabolites improve the nutraceutical value of the EVOOs modulating the phenolic profile and improving antioxidants activity. Full article