Highest Phenolic Content Research Articles

Antioxidant Activity, Inhibition of Intestinal Cancer Cell Growth and Polyphenolic Compounds of the Seagrass Posidonia oceanica's Extracts from Living Plants and Beach Casts.

The aim of the present study was to investigate the use of Posidonia oceanica for making products beneficial for human health. Firstly, we demonstrated that the antioxidant defense (i.e., SOD and APX activity) of P. oceanica's living leaves (LP) has low efficacy, as they partly neutralize the produced H2O2. However, high H2O2 levels led LP to produce, as a response to oxidative stress, high phenolic content, including chicoric acid, p-coumaric acid, caftaric acid, trans-cinnamic and rutin hydrate, as shown by UHPLC-DAD analysis. In addition, LP extracts inhibited intestinal cancer cell proliferation. Moreover, P. oceanica's beach casts consisting of either Wet 'Necromass' (WNP) or Dry 'Necromass' (DNP) were used for preparing extracts. Both DNP and WNP exhibited antioxidant and antiproliferative activities, although lower as compared to those of LP extracts. Although both P. oceanica's meadows and beach casts are considered priority habitats in the Mediterranean Sea due to their high ecological value, legislation framework for beach casts forbidding their removal is still missing. Our results suggested that both LP and DNP could be utilized for the production of high-added value products promoting human health, provided that a sustainability management strategy would be applied for P. oceanica's meadows and beach casts.

ULTRASOUND-ASSISTED DEEP EUTECTIC SOLVENT EXTRACTION OF PHENOLIC COMPOUNDS FROM ROSE MYRTLE

Rose myrtle fruits contain high levels of phenolics and other bioactive compounds. To increase the extraction efficiency of phenolic compounds, ultrasound-assisted- deep eutectic solvents (DESs) was proposed. First of all, six different DESs were used in this research and compared with traditional solvents (ethanol, methanol, and water), and the most suitable solvents for extracting phenolic compounds from rose myrtle fruits was choline chloride: urea (molar ratio of 1:2). Then, the Box–Behnken design was used to find the optimal extraction conditions (ultrasonic power (X1), solid to liquid ratio (X2), and extraction time (X3)) for the achievement of high total phenolic contents (TPC) and antioxidant activity (IC50). The results showed that the optimum ultrasound assisted-DES extraction parameters to achieve the highest TPC and antioxidant activity (IC50) (85.19 mgGAE/g fresh fruit and 2.31 mg/g, respectively) were X1 of 233 W, X2 of 440 mg/ml, and X3 of 55 min. Compared with traditional maceration extraction, ultrasound-assisted-DES has a higher TPC and antioxidant activity (IC50) and shorter extraction time. Scanning electron microscopy images (SEM) revealed that the dissolution of bioactive components was enhanced from the disrupted cells after ultrasound-assisted-DES extraction. Consequently, the combination of ultrasound-assisted-DESs extraction provide an excellent extraction method for efficient extraction of bioactive components of rose myrtle fruit.

Bioassay guided triterpene isolation and its biological evaluation using branches extract of a significant medicinal plant; Monotheca buxifolia

ObjectiveThe present study focuses on column chromatography of ethyl acetate fractions and re fractions of M.buxifolia branches for potential compound isolation alongside their biological and phytochemical evaluation and TLC analysis. MethodsThe obtained EtOAc fractions were subjected to phytochemical (TPC, TFC), antioxidant (TRP, TAC, DPPH, MC, ABTS), antibacterial and enzyme inhibition (α-amylase, lipase and urease) assays. Fractions indicating the presence of a compound were selected for running successive columns and their factions also analyzed employing the above mentioned bioassays. ResultsA collective none-to-low antibacterial activity was observed. MbBE11 presented the highest antidiabetic potential (79.92%±3.9) besides moderate phytochemical and antioxidant activity. Highest phenolic content (75.85±3.6 μgGAE/mg), flavonoid content (45.39±2μgQE/mg), antioxidant capacity (99.9±3.7 μgAAE/mg), reducing power (94.82±3.9 μgAAE/mg) and radical scavenging activity (DPPH; 86.28±3%, ABTS; 98.9±2.3%, MC; 59.01±2.7%) was reported by MbBE16 making it a potential source of antioxidant agents. Column chromatography of MbBE11 produced two refractions (MbBE21 and MbBE22) which reported moderate phytochemical and high antioxidant activity. High α-amylase and urease inhibition with low lipase inhibition was observed. MbBE21 depicted the largest ZOI against S.enterica (SE) (12±0.7 mm) and MbBE22 against Methicillin-resistant S.aureus (MRSA) (12±0.5 mm). Column chromatography of MbBE16 produced four refractions (MbBE31 – MbBE34) with moderate phytochemical and antioxidant activity without a single dominant fraction. Antibacterial activity remained low with the average ZOI sized at 7±0.5 mm. MbBE15 reported the highest anti-urease at 95.7%±4.7 and significant lipase inhibition at 85.5%±3. MbBE15, MbBE22 MbBE32 resulted in crystal formation later characterized as Lupeol with moderate phytochemical and antioxidant activity. ConclusionThe study concludes that M.buxifolia is a potential source of bioactive components and can be further explored through modern strategies.

Potential Hepatoprotective Effect of Matricaria Pubescens on High-Fat Diet-Induced Non-Alcoholic Fatty Liver Disease in Rats.

This study aimed to identify the phytochemical compounds of Matricaria pubescens by LC-MS/MS and evaluate the potential protective effect of its supplementation in high-fat diet (HFD)-induced non-alcoholic fatty liver disease (NAFLD) in adult rats through modulation of oxidative stress and histopathological changes. Twenty-four male rats were randomly divided into four groups. The first group served as control and received the standard diet. The second group (HFD) received a high-fat diet only (30 % of sheep fat). The third group's (control+MP) animals received a standard diet supplemented with 5 % M. pubescens (w/w). The fourth group (HFD+MP) received a high-fat diet supplemented with 5 % M. pubescens for 16 weeks. LC-MS/MS analysis showed that M. pubescens contains many phytochemical compounds. It was observed that the ethanolic extract of M. pubescens has a higher phenolic content than the aqueous extract. The supplementation of M. pubescens (5 % w/w) to HFD rats decreased significantly (p<0.01) body weight, liver and epididymal adipose tissue relative weights, glycemia, triglycerides (TG), insulin resistance, liver markers, TNF-α, malondialdehyde (MDA), protein carbonyl (PCO), advanced oxidation protein products (AOPP) level, and increased reduced glutathione (GSH) level, glutathione peroxidase (GPx), glutathione-S-transferase (GST), superoxide dismutase (SOD), and catalase activities as well as ameliorated histological alterations through the reduction hepatic lipid deposition and adipocytes hypertrophy compared to the HFD group. We conclude that M. pubescens powder may be effective for correcting hyperglycemia, hypertriglyceridemia, insulin resistance, and liver markers while decreasing inflammation and oxidative stress in the liver of high-fat diet-fed rats.

Carotenoid content, phytochemical screening, and antioxidant potential of Kantutay (Lantana camara L.), Katuray (Sesbania grandiflora L.), and Blue Ternate (Clitoria ternatea L.) flowers in the Philippines

Natural product chemistry plays a pivotal role in drug discovery and development. This study investigated the phytochemical profiles and antioxidant capacities of three prominent Philippine plants: Blue ternate (Clitoria ternatea), Kantutay (Lantana camara), and Katuray (Sesbania grandiflora). The primary aim is to provide a comprehensive assessment of their bioactive constituents and evaluate their potential for pharmacological applications. Phytochemical screening identified a diverse array of compounds, including flavonoids, tannins, glycosides, terpenoids, and other major chemical constituent classes, highlighting their therapeutic potential. The pigment analysis revealed substantial variations, with Blue ternate exhibiting the highest concentration, suggesting it as a promising source of carotenoids. Thin Layer Chromatography (TLC) and chlorophyll analysis further revealed distinct compound profiles. Total Phenolic Content (TPC) analysis and the DPPH radical scavenging method marked Blue ternate to have the highest phenolic content and the most potent antioxidant activity among the plant samples. These findings collectively emphasize the significant therapeutic potential of these plants, warranting further exploration for pharmaceutical development.

Short term supplementation with cranberry extract modulates gut microbiota in human and displays a bifidogenic effect

Cranberry is associated with multiple health benefits, which are mostly attributed to its high content of (poly)phenols, particularly flavan-3-ols. However, clinical trials attempting to demonstrate these positive effects have yielded heterogeneous results, partly due to the high inter-individual variability associated with gut microbiota interaction with these molecules. In fact, several studies have demonstrated the ability of these molecules to modulate the gut microbiota in animal and in vitro models, but there is a scarcity of information in human subjects. In addition, it has been recently reported that cranberry also contains high concentrations of oligosaccharides, which could contribute to its bioactivity. Hence, the aim of this study was to fully characterize the (poly)phenolic and oligosaccharidic contents of a commercially available cranberry extract and evaluate its capacity to positively modulate the gut microbiota of 28 human subjects. After only four days, the (poly)phenols and oligosaccharides-rich cranberry extract, induced a strong bifidogenic effect, along with an increase in the abundance of several butyrate-producing bacteria, such as Clostridium and Anaerobutyricum. Plasmatic and fecal short-chain fatty acids profiles were also altered by the cranberry extract with a decrease in acetate ratio and an increase in butyrate ratio. Finally, to characterize the inter-individual variability, we stratified the participants according to the alterations observed in the fecal microbiota following supplementation. Interestingly, individuals having a microbiota characterized by the presence of Prevotella benefited from an increase in Faecalibacterium with the cranberry extract supplementation.

Comparative Antioxidant Potentials and Quantitative Phenolic Compounds Profiles among the Flowers and Leaves from Various Chrysanthemum morifolium Cultivars.

Chrysanthemum morifolium is a valuable plant that contains a wide range of phytochemical compounds and exhibits various biological activities. Ethanol extracts from both the leaves and flowers of 17 different cultivars of C. morifolium were tested for antioxidant activities using the 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) assays and were quantitatively analyzed for 12 phenolic compounds using high-performance liquid chromatography with diode-array detection. We found that the 'Ford' and 'Raina' cultivars demonstrated strong antioxidant abilities and high phenolic compound contents compared to other cultivars, while the flowers of 'Cielo' and the leaves of 'White Cap' exhibited low antioxidant capacity in both assays. The 'Cielo' cultivar also displayed the lowest compound contents. Additionally, in most samples, 3,5-dicaffeoylquinic acid and 4,5-dicaffeoylquinic acid stood out as high-content compounds in the extracts. This study provides foundational knowledge that can be used for selecting appropriate C. morifolium cultivars for further research. Moreover, the 'Ford' and 'Raina' cultivars, containing high amounts of bioactive compounds and showing superior antioxidant ability, could be applied to produce health-beneficial products.

Biosynthesis of TiO2 nanostructures using Camellia sinensis extract (polyphenols) and investigation of their execution as photoanodes in photovoltaic device

Titanium dioxide (TiO2) nanoparticles (NPs) are indeed widely recognized and utilized as one of the most prominent photoanode materials in dye-sensitized solar cells (DSSCs). Therefore continuous efforts have been made to improve the performance of TiO2 photoanodes in terms of light absorption, charge carrier mobility, and overall energy conversion efficiency. Green synthesis methods for the production of TiO2 NPs, including the use of plant-based reducing agents, have gained significant attention in recent years. These methods are considered environmental friendly alternatives to traditional physical and chemical synthesis methods, which often involve the use of hazardous chemicals and complex processes. Therefore, in this work, a variety of tea types, including green, white, black, oolong, pu-erh have been used to synthesize TiO2 NPs. The differences in the amount of phenolic compounds and caffeine in various tea varieties can influence the topology, structure, and composition of the as synthesized nanoparticles (NPs). The prepared TiO2 NPs were comprehensively characterized for particle size, morphology, purity, composition, crystalline nature, structural, electrochemical and photovoltaic capabilities. The as synthesized titanium oxide (TiO2) NPs were spherical in shape and particle sizes ranged from 10 to 20 nm with little agglomerations. For DSSC application, thin films of synthesized TiO2 NPs were prepared by making paste of TiO2 NPs with Triton-X and spread onto conducting substrate (FTO) with the help of glass rod and finally sintering for 1 h at 450 °C. The prepared TiO2 electrodes were dipped in the standard N719 dye solution (0.1 × 10−3 M) in acetonitrile medium overnight for complete adsorption. Overall efficiency = 3.0 %, JSC = 9.72 mA/cm2, VOC = 660 mV and FF = 0.46 was achieved with the DSSC made up with green tea mediated TiO2 NPs based photo anode. Due to high phenolic content and good reductive properties, TiO2 NPs prepared using green tea extract were highly crystalline in nature, have high surface area, high roughness factor, good stability which results in maximum dye loading and hence increase in the overall conversion efficiency.

Ultrasound-Assisted Extraction, Optimization, Phytochemical Screening and Analysis of Phenolics from Cycas Zeylanica and Antioxidant Activity Evaluation.

The present study focuses on investigating the phytochemical screening of indigenous species, C. zeylanica, for the first time. The leaf extracts have been prepared using ultrasound-assisted methods to obtain the best extraction results using different time and temperature conditions such as 30, 60, and 90 min. and 30, 40, and 60 °C, respectively. The results have been optimized using response surface methodology. Under the optimal extraction conditions of 60 °C for 43.57 minutes, an extract was produced with a yield of 0.238 g and a high total phenolic content of 181.1965 mg GAE/g. The total phenolic content has been evaluated and the presence of gallic acid has been confirmed through the HPLC technique. The optimal extract (OE) showed excellent antioxidant activity for the DPPH assay, with an IC50 of 3.1 μg/ml. Finally, GC-MS profiling has been done to screen the volatile component of the plant extract.

Unlocking the potential of oil by-products: Investigating the influence of co-culture fermentation on phenolic acid degradation in side stream blends from oil and dairy industry

According to the newest trends in food waste management, the priority for valorisation of oil and dairy industry by-products was recognised. New approach of blending side streams of plant and animal origin has been proposed for obtaining future foods with improved nutritional value. Major obstacle in valorising sunflower seed cake (SSC) and whey (W) is their perishability and a relatively high content of phenolics contributing to, among others, protein indigestibility. In the study, a new approach of microwave pre-treatment applied for SSC and W blends was used. Its influence on phenolic acids and antioxidant properties after fermentation with co-culture of lactic acid bacteria and yeast was examined. Microwave drying of blends was longer than that of SSC affecting phenolic acids content. Fermentation by L. lactis and K. lactis caused pH decrease and increase in total acidity in 48 h effectively limiting the growth of bacterial contaminants. Fermentation decreased the content of phenolic acids, especially in blend composed of SSC and W (8.75:1; w/w) with the highest content of these constituents (from 1611.3 down to 838.8 mg/100 g dry matter). The study showed the synergistic effect of pre-treatment method and fermentation in terms of reduction in phenolic acids in new food matrices.

Effects of static magnetic field-prolonged supercooling preservation on blueberry quality

Although refrigeration and freezing are commonly used methods for preserving blueberries, refrigeration is only suitable for short-term preservation (storage at 4 °C for approx. 1 month), whereas ice crystals that form during freezing can lead to a degradation of blueberry quality. However, supercooling, which combines the advantages of freeze-free low-temperature storage, offers a novel alternative preservation method. In this study, we demonstrate that 10 mT static magnetic field treatment reduces the nucleation temperature of blueberries to below −6 °C and enhances their supercooling. The combination of static magnetic and temperature fields was found to prolong the effective storage of supercooled blueberries for up to 35 days, during which time, we detected no ice nucleation. Compared with refrigeration and freezing, the firmness of the supercooled-preserved blueberries increased by 24.1% and 31.2%, respectively, with corresponding reductions of 3.8% and 4.69% in weight loss. These changes were associated with a retardation of the decline in organic acid and soluble solid contents, along with the maintenance of high total phenolic and anthocyanin contents, antioxidant capacity, and the activities of polyphenol peroxidases and peroxidases. Collectively, our findings in this study indicate that supercooling would be an effective new approach for the preservation of blueberries.

Antioxidant Activity of Single Black Garlic (Allium sativum L.) Ethanol Extract and Its Potential for Oral and Dental Health

Allium sativum L., or fermented single garlic, is an garlic that is heated for 14 days at 70°C with a humidity of 70–80% to turn it black. In this study, the total phenolic content and antioxidant activity of an ethanol extract from a single black garlic (Allium sativum L) are to be determined. Maceration is used to extract a single black garlic (Allium sativum L), and the folin-ciocalteau method is used to measure total phenolics. Using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) technique, antioxidants were evaluated. The results of the study demonstrate that the ethanol extract of a single black garlic (Allium sativum L) has a total phenolic content of 62,45% ± 0,2886 and that the extract's antioxidant activity has an IC50 value of 10.4156 μg/mL (very strong antioxidant). The high phenolic content and antioxidant activity which is classified as very strong indicate that single black garlic ethanol extract has potential for oral and dental health.

An Eco-Friendly Extraction and Purification Approach for Obtaining Active Ingredients for Cosmetics from Two Marine Brown Seaweeds.

Brown seaweeds are attracting attention due to their richness in bioactive compounds, in particular, their phlorotannins. We present here a case study of two Fucales, Ascophyllum nodosum and Halidrys siliquosa, sustainably collected, to produce active polyphenols for the cosmetics sector. Phenolic contents of crude extracts, obtained by Accelerated Solvent Extraction (ASE), were more elevated in H. siliquosa at 100.05 mg/g dry weight (DW) than in A. nodosum (29.51 mg/g DW), considering 3 cycles with cell inversion. The temperature of extraction for a high phenolic content and high associated antioxidant activities close to positive controls was 150 °C for both algae and the use of only one cycle was enough. A semi-purification process using Solid-phase Extraction (SPE) was carried out on both ASE crude extracts (one per species). The majority of phlorotannins were found in the ethanolic SPE fraction for A. nodosum and the hydroethanolic one for H. siliquosa. The SPE process allowed us to obtain more concentrated fractions of active phenolic compounds (×1.8 and 2 in A. nodosum and H. siliquosa, respectively). Results are discussed in regard to the exploitation of seaweeds in Brittany and to the research of sustainable processes to produce active natural ingredients for cosmetics.

A Review of the Pharmacological effects of Alpinia galanga Linn. and it’s Phytoconstituents

Middle class people who live in rural or urban areas often find it difficult to get modern health services, so they more often use traditional medicines obtained from herbal plants that grow around them. From the ancient Vedic era, green plants are being used for their medicinal properties to treat several diseases. Green plants represent a big source of bioactive compounds. Alpinia galanga (Linn.) of Zingiberaceae family is one amongst those medicinally important plants. Alpinia galanga plant is used in medicine and in food preparation. Rhizome extract of Alpinia galanga have high phenolic and flavonoid contents when compared to leaf extract. Because of elevated phenolic and flavonoid content in rhizome extract of Alpinia galanga there is noticeable antimicrobial as well as radical scavenging potential. It is a well-known official drug thought out the country as integrated contribution of nature. It is commonly used for the management of eczema, coryza, bronchitis, otitis interna, gastritis, ulcers, morbilli and cholera, pityriasis versicolor, to clear the mouth, emaciation. The different parts of the plant have various effects like antifungal, antiprotozoal, antiplatelet, antiviral, antidiabetic, immunomodulatory, antibacterial, anti-oxidant effects, hypolipidemic and many others. The current review add significant information about its, pharmacological activities, medicinal properties and phytochemical investigations as a traditional drug to cure for a number of diseases. Every fraction of the plant has valuable properties that can deliver humanity. The complete plant will be broadly investigated for further future prospective.

Extraction of macroalgae phenolic compounds for cosmetic application using eutectic solvents

Cosmetic industry remains a major focus of economic development in the 21st century, while consumer's demand for sustainability drives the search for new active natural ingredients and the development of green extractions techniques. The aim of this work is to obtain antioxidant-enriched extracts from two seaweeds found on the Portuguese shore, Sargassum muticum and Gelidium corneum using natural deep eutectic solvents (NADES) to be used in cosmetic formulations. Extracts were obtained by maceration of powdered seaweeds with aqueous solutions (25 % (v/v) in water) of different NADES, L-lactic acid: fructose (5:1), L-lactic acid: glucose (5:1) and L-lactic acid: sodium acetate (7:1). The resulting extracts were evaluated regarding their total phenolic content (TPC) using the Folin-Ciocalteu method and antioxidant capacity by the DPPH and FRAP assays. L-lactic acid: fructose (5:1) NADES yielded Sargassum muticum extracts with the highest phenolic content (2099 mg GAE/L) and the highest antioxidant activities (DPPH reduction of 27 %, FRAP 30 μM FeSO4). Antimicrobial activity of the extracts over three microorganisms of the skin microbiota, the bacteria Staphylococcus epidermidis and Cutibacterium acnes and the fungus Malassezia furfur, revealed no relevant antimicrobial effect, meaning that extracts did not affect the skin microbiota homeostasis. The extract with the highest cosmeceutical interest, S. muticum extract prepared using L-lactic acid: fructose (7:1), was incorporated into a topical O/W emulsion. Physical and rheology data of the cosmetic formulation ensure its quality and safety. Finally, compatibility, acceptability and antioxidant efficacy were evaluated in vivo, in human volunteers. The results show that NADES are a promising replacement of conventional solvents in the extraction of antioxidants from biomass and their use in topical formulations is safe.

Liquid chromatography-tandem mass spectrometry profile and antioxidant, antimicrobial, antiproliferative, and enzyme activities of Thymus pectinatus and Thymus convolutus: in vitro and in silico approach.

The objective of this study is to investigate the antiproliferative, antioxidant, antimicrobial, and enzyme activity capacities and phytochemical compositions of Thymus pectinatus (TP), Thymus convolutus (TC), which are endemic to Türkiye. Quantitative analysis of phenolic compounds in the extracts was conducted using liquid chromatography-tandem mass spectrometry, targeting 53 phenolic compounds. Rosmarinic acid, quinic acid, and cynaroside were identified as the major compounds, exhibiting quantitative variation in both extracts. The extracts had a high total phenolic content, with 113.57 ± 0.58 mg gallic acid equivalents (GAE)/g extract for TP and 130.52 ± 1.05 mg GAE/g extract for TC. Furthermore, although both extracts exhibited high total flavonoid content; the TP extract (75.12 ± 1.65 mg quercitin equivalents (QE)/g extract) displayed a higher flavonoid content than the TC extract (30.24 ± 0.74 mg QE/g extract) did. The extracts had a promising antiproliferative effect on C6, HeLa, and HT29 cancer cell lines with a less cytotoxic effect (10.5-14.2%) against normal cells. Both extracts exhibited very potent inhibitory activity against the xanthine oxidase enzyme, with half-maximal inhibitory concentration values of respectively 2.07 ± 0.03 μg mL-1 and 2.76 ± 0.06 μg mL-1 and moderate activity against tyrosinase and α-glucosidase. Docking simulations proved that rosmarinic acid and cynaroside, the major components of the extracts, were the most potent inhibitors of xanthine oxidase. According to antimicrobial activity results, the TC extract exhibited moderate activity against Staphylococcus aureus, and the TP extract had strong activity against both Enterococcus faecium and S. aureus. These findings emphasize the beneficial effects of the two endemic Thymus species on human health and suggest their potential use as plant-derived bioactive agents. © 2024 Society of Chemical Industry.

Chymotrypsin and Trypsin Inhibitory Activity of Some Medicinal Plants Collected from Rize (Türkiye).

In this research, the evaluation of in vitro chymotrypsin and trypsin inhibitory activities of ten plant species collected from Rize were aimed, and fractions that showed strong activity were analyzed through HPLC. Daphne pontica L. and Mentha longifolia (L.) L. were found to have the highest chymotrypsin inhibitory activities (87.75 and 84.24 % inhibition). Similarly, the highest trypsin inhibitory activity was observed in D. pontica (%99.93 inhibition), followed by Sambucus ebulus L. flowers (87.47 % inhibition). Extracts showing strong enzyme inhibition were fractioned and subjected to activity tests. The highest chymotrypsin inhibitory activity was observed in the n-hexane fraction of D. pontica (%80.70 inhibition), while the highest trypsin inhibitory activity was found in the n-butanol fraction of S. ebulus (%86.81 inhibition). HPLC studies determined that the 80 % ethanol extract of D. pontica and its dichloromethane and ethyl acetate fractions contained umbelliferone. It was found that chlorogenic acid was present in the 80 % ethanol extracts of S. ebulus flowers. M. longifolia was found to contain chlorogenic acid, caffeic acid, luteolin-7-glucoside, and rosmarinic acid. M. longifolia has been identified as the plant exhibiting the highest antioxidant activity in ABTS and CUPRAC tests, consistent with its high phenolic and flavonoid content.

Identification and characterization of lettuce cultivars with high inhibitory activity against the human pathogen Escherichia coli O157:H7: Toward a plant-intrinsic hurdle approach to microbial safety

Foodborne illness linked to fruit and vegetables poses a major challenge to public health and horticulture production. Processed lettuce has been implicated in recurrent outbreaks of pathogenic Shiga toxin-producing Escherichia coli (STEC) infection. We hypothesized that plant defenses elicited by mechanical injury may effect STEC inhibition in cut leaves. Intact and cut leaves of 31 lettuce cultivars (Lactuca spp.) selected from >500 accessions based on their resistance to common insect pests and the necrotrophic lettuce drop pathogen were assessed for STEC serovar O157:H7 (EcO157) survival under cold storage conditions. The cultivars were previously ranked also for phenotypes such as resistance to other phytopathogens and physiological traits. Total leaf phenolic compounds, anthocyanins, and reactive oxygen species (ROS); and phenylalanine lyase (PAL), peroxidase (POD), and polyphenol oxidase (PPO) activity were quantified in each cultivar. Principal Component Analysis (PCA) and K-means cluster analysis were applied to group phenotypes and EcO157 population decline on lettuce. In five cultivars, high resistance to herbivorous insects (aphids, leaf miners and thrips), diseases (lettuce drop, downy mildew, and Impatiens Necrotic Spot Virus), and the disorder tipburn was associated with up to 42-fold EcO157 population decline on cold-stored cut (shredded) leaves, and with up to 11-fold difference in decline on cold-stored intact vs cut leaves (ΔD). The decline on these cold-stored cut cultivars also was up to 24-fold greater than on the cultivar with the lowest decline, and up to 8-fold greater than the mean decline for all 31 cultivars (P < 0.01). Resistance to the hemibiotrophic pathogen causing lettuce bacterial leaf spot, Xanthomonas hortorum pv. vitians, was not indicative of high EcO157 inhibition in this system. High PAL activity, and phenolic and anthocyanin content (PPA); and high PAL and POD activity, were associated with high EcO157 population decline (P < 0.05). One cultivar with high susceptibility to herbivorous insects and phytopathogens, and low levels of defense metabolism nevertheless showed high EcO157 inhibition, suggesting other plant inhibitory characteristics at play. Basal plant immunity and pathways associated with a strong wound response may inform about enteric pathogen survival on minimally processed postharvest lettuce. The related traits identified in this study may serve to breed new genotypes with intrinsically enhanced microbial safety.

Strain-specific features of Pleurotus ostreatus growth in vitro and some of its biological activities

BackgroundThe production of Pleurotus ostreatus mycelium as a promising object for use in food and other industries is hampered by a lack of information about the strain-specificity of this fungus mycelium growth and its acquisition of various biological activities. Therefore, this research aimed to investigate mycelial growth of different P. ostreatus strains on varies solid and liquid media as well as to evaluate strains antagonistic, antibacterial, antiradical scavenging activities, and total phenolic content.ResultsPotato Dextrose Agar medium was suitable for all strains except P. ostreatus strain 2460. The best growth rate of P. ostreatus 2462 strain on solid culture media was 15.0 ± 0.8 mm/day, and mycelia best growth on liquid culture media—36.5 ± 0.2 g/l. P. ostreatus strains 551 and 1685 were more susceptible to positive effect of plant growth regulators Ivin, Methyur and Kamethur. Using of nutrient media based on combination of natural waste (amaranth flour cake and wheat germ, wheat bran, broken vermicelli and crumbs) has been increased the yield of P. ostreatus strains mycelium by 2.2–2.9 times compared to the control. All used P. ostreatus strains displayed strong antagonistic activity in co-cultivation with Aspergillus niger, Candida albicans, Issatchenkia orientalis, Fusarium poae, Microdochium nivale in dual-culture assay. P. ostreatus 2462 EtOAc mycelial extract good inhibited growth of Escherichia coli (17.0 ± 0.9 mm) while P. ostreatus 2460 suppressed Staphylococcus aureus growth (21.5 ± 0.5 mm) by agar well diffusion method. The highest radical scavenging effect displayed both mycelial extracts (EtOH and EtOAc) of P. ostreatus 1685 (61 and 56%) by DPPH assay as well as high phenolic content (7.17 and 6.73 mg GAE/g) by the Folin-Ciocalteu’s method. The maximal total phenol content (7.52 mg GAE/g) demonstrated of P. ostreatus 2461 EtOH extract.ConclusionsIt is found that the growth, antibacterial, antiradical scavenging activity as well as total phenolic content were dependent on studied P. ostreatus strains in contrast to antagonistic activity. The proposed culture mediums of natural waste could be an alternative to commercial mediums for the production mycelial biomass of P. ostreatus strains.

Natural- and in vitro-grown Filipendula ulmaria (L.) Maxim: evaluation of pharmaceutical potential (antibacterial, antioxidant and toxicity) and phenolic profiles

Meadowsweet (Filipendula ulmaria (L.) Maxim) is Rosaceae family perennial herb. Traditional uses of F. ulmaria include inflammatory problems like rheumatism, arthrosis, and arthritis), gastrointestinal disorders, liver malfunction, and gout. The pharmaceutical industry has been very interested in this plant because of its health benefits. The presence of phenolic secondary metabolites is thought to be the primary cause of meadowsweet's biological activity and therapeutic efficacy. This study was intended to compare and evaluate the biological activities (antibacterial, antioxidant, antitumor and toxicity) and phenolic profiles (total phenol-flavonoid content and individual phenolic constituents) of F. ulmaria aerial parts obtained from two different sources (naturally- and in vitro-grown). Antibacterial activity was evaluated using 17 different bacteria (10 human and 7 fish pathogens) with disc diffusion method. Methanolic extracts of in vitro-grown parts showed higher antibacterial effect than naturally-grown parts with all tested bacterial pathogens (human and fish). On the other hand, other extracts (aqueous, ethanol, hexane, and ethyl acetate) demonstrated higher antibacterial potential with field-grown parts. The highest sensitivity was observed with Staphylococcus epidermidis, S. aureus and Enterobacter cloacae to aqueous extract of field-grown plants. The potent antibacterial activity of F. ulmaria extracts rendered the Agrobacterium tumefaciens-induced potato disc tumor assay inapplicable. Toxicity assay (brine shrimp) showed that aqueous extract of both sources had the lowest toxicity. Methanolic extract of both parts had a strong antioxidant potential (DPPH radical scavenging activty) having IC50 values as 205.65 µg/mL and 206.74 µg/mL, respectively, and similar level of overall total phenol-flavonoid contents. Individual phenolic analysis with HPLC-DAD showed that the most prevalent phenol was rutin in both sources. While the quantities of chlorogenic acid in both aerial parts were similar, the parts that were grown naturally had higher levels of salicylic acid and rutin. These findings demonstrated the effective antibacterial and antioxidant properties, high phenolic content, and low toxicity of both F. ulmaria sources, indicating that they can be utilized in nutraceutical industry due to their high health promoting potential.