Antioxidant and free radical-scavenging properties of ethanolic extracts of defatted borage (Borago officinalis L.) seeds

Can Origanum be a hope for cancer treatment? A review on the potential of Origanum species in preventing and treating cancers

In this study, the potential of aromatic Origanum species belonging to Lamiaceae family to prevent and treat cancer was investigated. Since aromatic plants contain phytochemicals such as essential oils, phenolic acids, terpenoids, flavonoids, alkaloids, vitamins, enzymes and minerals with beneficial biological activities, they have become more interesting and important in medicine, pharmacy and industry. Publications/research between 1950 and 2022 were screened to investigate the effects of Origanum species on cancer, and the effects of their extracts and essential oils in cancer prevention and treatment. Essential phytochemicals found in plants provide efficacy in the prevention and treatment of many diseases. Besides, the essential oils found in these plant extracts are another reason that makes them important. Therefore, it is preferred in traditional medicine in the fight against many diseases as well as cancer. Essential oils of Origanum species mainly contain monoterpenes such as p-cymene, carvacrol, thymol and γ-terpinene. Since these compounds exhibit anticancer properties, Origanum species are becoming the plants of choice in the fight against cancer. In this context, Origanum majorana L. Origanum vulgare and Origanum munzurense are promising species, considering the composition of their extracts and essential oil.

Discovery of imeglimin-inspired novel 1,3,5-triazine derivatives as antidiabetic agents in streptozotocin-induced diabetes in Wistar rats via inhibition of DPP-4

Novel 1,3,5-triazine derivatives bearing oxazine have been synthesized and tested for their ability to inhibit a panel of dipeptidyl peptidase (DPP)-4, 8, and 9 enzymes. In a comparative inhibitory assay, the molecules showed potent inhibition of DPP-4 ranging from IC50 of 4.2 ± 0.30-260.5 ± 0.42 nM, with no activity against DPP-8 and DPP-9. Among the tested series, compound 8c demonstrated the strongest DPP-4 inhibitory activity with an IC50 of 4.2 ± 0.30 nM. It also showed the greatest binding affinity during docking studies with DPP-4 with a docking score of -8.956 and a glide energy of -78.546 kcal mol-1 and was found oriented in the S1 and S2 pockets of the DPP-4 active site, which is composed of the catalytic triad Ser 630, Asp 710, and His 740. The in vivo pharmacological assay revealed that compound 8c in a dose-dependent manner improved the insulin level, body weight, antioxidants, and HDL, and reduced the levels of blood glucose, LDL, and VLDL in streptozotocin-induced diabetes in Wistar rats. Our study demonstrated the discovery and development of novel 1,3,5-triazine derivatives bearing oxazine as a novel class of anti-diabetic agents via inhibition of DPP-4.

Discovery of novel 1,3,5-triazine derivatives as an antidiabetic agent in Wistar rats via inhibition of DPP-4

Aim: To develop imeglimin-inspired novel 1,3,5-triazine derivatives as antidiabetic agents. Materials & methods: These derivatives were synthesized and tested against DPP enzymes. Compound 8c was tested for in vivo antidiabetic activity in streptozotocin-induced diabetes in Wistar rats by estimating various biochemical parameters. Docking experiments were also performed. Results: Compound 8c was identified as a selective and potent DPP-4 inhibitor. It was proficiently docked into the catalytic triad of Ser 630, Asp 710 and His740 in S1 and S2 pockets of DPP-4. In experimental animals, it also showed dose-dependent improvement in blood glucose, blood insulin, bodyweight, lipid profile and kidney and liver antioxidant profiles. Conclusion: This study demonstrated the discovery of imeglimin-inspired novel 1,3,5-triazines as a potent antidiabetic agent.

Phenolic Profile and Comparison of the Antioxidant, Anti-Ageing, Anti-Inflammatory, and Protective Activities of Borago officinalis Extracts on Skin Cells

In this study, methanol and water-methanol extracts of borage (Borago officinalis) herb dried using various methods were analysed for their phenolic profile and biological activity. Twelve compounds, including flavonoids (astragalin, kaempferol 4-glucoside, rutoside, and vitexin) and phenolic acids (caffeic, chlorogenic, 3,4-dihydroxyphenylacetic, ferulic, p-hydroxybenzoic, protocatechuic, rosmarinic, and syringic), were determined qualitatively and quantitatively in B. officinalis extracts by the HPLC-DAD method. The highest total flavonoid content was confirmed for the methanol extract from the hot-air-dried herb, while the methanol extract from the air-dried herb was most abundant in phenolic acids. The results of in vitro tests on human keratinocytes (HaCaT) and fibroblasts (BJ) showed that the extracts were able to reduce the intracellular level of reactive oxygen species in skin cells. Tests performed to assess inhibition of protein denaturation, lipoxygenase activity, and proteinase activity demonstrated that borage extracts have anti-inflammatory properties. In addition, the methanol extract of the herb dried in a convection oven showed the strongest inhibition of both collagenase and elastase activity, which is indicative of anti-ageing properties. The results show that the borage extracts are a source of valuable bioactive compounds with beneficial properties in the context of skin cell protection.

Chemical Composition and Functional Properties of Dietary Fibre Concentrates from Winemaking By-Products: Skins, Stems and Lees

The objective of this study was to evaluate, from a technological and nutritional point of view, the chemical composition and functional properties of the industrial winemaking by-products, namely skins, stems and lees. The chemical and physical characteristics, as well as the functional properties (fat and water retention and swelling capacity, antioxidant capacity, and their prebiotic effect), of the dietary fibre of these by-products were studied. The results showed that the skins, stems, and lees are rich in fibre, with the stem fibre containing the highest amounts of non-extractable polyphenols attached to polysaccharides with high antioxidant activity and prebiotic effect. Lee fibre had the highest water retention capacity and oil retention capacity. The results reveal that winemaking by-products could be used as a source of dietary fibre with functional characteristics for food applications.

Optimization and modeling of microwave-assisted extraction of curcumin and antioxidant compounds from turmeric by using natural deep eutectic solvents

Natural deep eutectic solvents (NADES) have recently come to the fore as new green solvents for foods, cosmetics and pharmaceuticals due to their unique solvation power and low toxicity. Turmeric extracts were prepared using the microwave assisted extraction method (MAE) using five NADES containing binary combinations of choline chloride, lactic acid, fructose, and sucrose. The MAE method was optimized and modeled by using response surface methodology to obtain maximum total antioxidant capacity (TAC) and curcumin contents (CC) in extracts for each NADES. All NADES extracts, except NADES-1 containing fructose and cholin chloride, exhibited higher TAC and CC than those in 80% methanol:water which was the preferred solvent in literature. NADES solvents did not interfere with subsequent antioxidant capacity measurements using the CUPRAC method. The proposed MAE is a potentially efficient and sustainable procedure in pharmaceutical and food industries for the extraction of antioxidants and curcumin from turmeric.

Antioxidant potential and physicochemical properties of protein hydrolysates from body parts of North Atlantic sea cucumber (Cucumaria frondosa)

Abstract

Protein hydrolysates were prepared from North Atlantic sea cucumber (Cucumaria frondosa) body wall (BW), and processing by-product flower (FL) and internal organs (IN). Sea cucumber proteins from these three tissues were hydrolysed with selected endopeptidases and exopeptidases. The enzymes used were Alcalase (A), and Corolase (C) as endopeptidases and Flavourzyme (F) with both endo- and exopeptidase functions. These were employed individually or in combination under controlled conditions. The hydrolysates so prepared were subsequently analysed for their antioxidant potential and functionalities in food systems for the first time. Hydrolysates treated with the combination of A and F exhibited the highest radical scavenging activity against DPPH and ABTS radicals. The highest metal chelation activity was observed for samples hydrolysed with the combination of enzymes (C + F and A + F). All treatments inhibited beta-carotene bleaching in an oil-in-water emulsion and TBARS production in a meat model system. In addition, sea cucumber protein hydrolysates were more than 75% soluble over a pH range of 2–12. Hydrolysed proteins were also effective in enhancing water holding capacity in a meat model system compared to their untreated counterparts. The amino acids of sea cucumber protein hydrolysates had desirable profiles with glutamic acid as the predominant component in samples analysed. These findings demonstrate the desirable functionalities of hydrolysates from North Atlantic sea cucumber and their potential for use as functional food ingredients.

Graphical abstract

Potential Use of Hyssopus officinalis and Borago officinalis as Curing Ingredients in Pork Meat Formulations

Simple Summary

Health risks associated with nitrites as curing agents have led consumers to search for products without those additives. Herbs have been used in medicine for many years and are usually positively perceived by consumers. Good-quality products with medicinal plants may be an alternative for those who try to avoid additives other than salt and spices. Hyssopus officinalis and Borago officinalis were tested for their potential to be used as colour forming and antioxidant agents. Both herbs were used in pork meat formulations along with nitrate reducing bacteria. A colour formation similar to a control product containing nitrite was noted in all the samples. Borage had a stronger antioxidant effect. Those additives can be used as an alternative to nitrite cured pork products.

Abstract

The replacement of nitrites in pork meat products has been a studied issue for many years. Due to potential health threats associated with these additives, consumers tend to search for alternative meat curing methods. In this study, Hyssopus officinalis and Borago officinalis were tested for their potential to be used as colour-forming and antioxidant agents. Dry plant samples from various sources were tested for fat, protein, ash, polyphenol and nitrate content. There were significant differences between the herbs depending on source. Two control samples (containing curing salt and sodium chloride with nitrate reducing bacteria) and samples with herbs (hyssop, hyssop with nitrate reducing bacteria, borage, borage with nitrate reducing bacteria)—0.5% of the meat mass—were prepared and stored for 15 days. In the samples with herbs and bacterial cultures, a red colour was developed, the TBARS values were low and DPPH activity was strong. All the samples with herbs had lower residual nitrite levels compared to the samples with curing salt. Borage had a stronger influence on colour and antioxidant stability of the meat samples compared to hyssop. However, both herbs can be used as colour-forming and antioxidant agents along with nitrate-reducing bacteria.

Effectiveness of Echium amoenum on premenstrual syndrome: a randomized, double-blind, controlled trial

Background

The present study aimed to evaluate the effect of Echium amoenum (EA) on the severity of premenstrual syndrome (PMS) in comparison with placebo.

Methods

The present study was a randomized double-blind controlled clinical trial. A checklist questionnaire was completed by 120, 18 to 35-year-old, college students. And then, 84 eligible women (20 to 35 years old) were enrolled in the trial; they were randomly assigned to two groups of intervention (EA) and control (placebo), with 42 participants in each group. Participants in the intervention group received 450 mg capsules of EA per day (three times a day) from the 21st day of their menstrual cycle until the 3rd day of their next cycle for two consecutive cycles. The severity of PMS was measured and ranked using the premenstrual symptoms screening tool (PSST). The generalized estimating equation was used to compare the total score of the severity of PMS between the two groups.

Results

Sixty-nine women with regular menstrual cycles suffering from PMS completed the study. The mean scores of the symptoms in the EA group were 35.3 and 16.1 (P ≤ 0.001) at baseline and after 2 months, respectively, while the mean scores of the symptoms in the placebo group were 31.0 and 28.3 (P = 0.09) at baseline and after 2 months, respectively. The evaluation of the first and the second follow-ups in the intervention group showed that, after being adjusted for age and body mass index (P ≤ 0.001), the mean scores of the premenstrual syndrome, using GEE analysis, have decreased to 6.2 and 11.6, respectively.

Conclusion

Based on the results, in comparison with the placebo group, EA was found to be more effective in improving the symptoms of PMS, and is highly recommended for treatment of this syndrome.

Trial registration

IRCT2015110822779N3; Registration date: 2015–11–27.

Properties and characterization of thyme essential oil incorporated collagen hydrolysate films extracted from hide fleshing wastes for active packaging

In this investigation, collagen hydrolysate (CH) films extracted from hide fleshing wastes were successfully developed using solvent casting method by incorporating different concentrations of thyme essential oil (TO) (2%, 4%, 6%, and 8%) into the CH. Depending on the concentration of TO, thickness, tensile strength (TS), elongation at break (EAB), film solubility (FS), color, opacity, light transmittance, and thermal properties varied. Addition of TO resulted in the increases in the thickness, EAB (%), and light barrier performance of CH-TO films while there was a significant decrease in TS and FS of the CH films (p ≤ 0.05). According to our findings, the increment of TO content induced higher lightness and yellowness but lower redness values compared to CH film. Fourier-transform infrared spectroscopy was conducted to determine the molecular changes and interactions between CH extracted from hide fleshing wastes and TO. In order to analyze the thermal behavior of the films, differential scanning calorimetry analysis was conducted. Moreover, the structure-property relationships of CH and TO were examined by scanning electron microscopy and a reduction in the compact and homogenous structures of the films containing TO was observed. Promising results have been obtained showing that CH-based films can be used for active packaging purposes, thereby contributing to a significant reduction in the environmental impact of both leather solid waste and plastic packaging materials.

Betacyanins from Hylocereus polyrhizus: pectinase-assisted extraction and application as a natural food colourant in ice cream

The effect of solvent, substrate-to-solvent ratio and concentration of pectinase on the extraction of betacyanins from the pulp of red pitahaya (Hylocereus polyrhizus) was evaluated with respect to yield, betacyanin content (BC) and total sugar content. The application of betacyanins from red pitahaya in ice cream was then evaluated by comparison to a commercial colourant, E-162. Without the use of pectinase, the highest yields (9.11 ± 0.35%) of betacyanins were obtained using 95% ethanol at a substrate-to-solvent ratio of 1:1. With the use of pectinase at a concentration of 1.5%, the highest yield (17.11-17.45%) of betacyanins were obtained using water as a solvent at a substrate-to-solvent ratio of 1:1 and 1:2. Pectinase treatment (1.5-2.5%) using water as a solvent yielded betacyanins with the highest BC (126.47-130.83 g kg^-1) and lowest total sugar content (57.85-59.74 g kg^-1). The BC and total colour changes were similar in ice cream containing betacyanins from red pitahaya and E-162 throughout the 21-days of frozen storage at -18 °C. Betacyanins from red pitahaya or E-162 enhanced the antioxidant properties of ice cream. The sensory evaluation of ice cream containing betacyanins from red pitahaya showed a better colour acceptability than E-162.

Development of Nanoemulsion Preconcentrate of Capsanthin with Improved Chemical Stability

Capsanthin, like other carotenoids, exhibits poor aqueous solubility, poor stability, and low/variable oral bioavailability that limit its utility as a nutraceutical. In this study, we describe the development of anhydrous nanoemulsion preconcentrate of capsanthin, which upon dilution with water, spontaneously forms nanoemulsion resulting in improved solubility of capsanthin without compromising its chemical stability and antioxidant activity. We chose Food and Drug Administration-approved ingredients to develop capsanthin nanoemulsion preconcentrates. The optimized capsanthin nanoemulsion preconcentrate, upon dilution with water or buffers, yielded the nanoemulsion with size <50 nm and showed ∼8-fold higher capsanthin release in 1 h in 0.1 N HCl in vitro compared with pristine capsanthin. The 3-month stability studies at 25°C on the capsanthin nanoemulsion preconcentrate showed that capsanthin retained the physical and chemical stability with no alteration in antioxidant activity indicating that nanoemulsion preconcentrate can be used to effectively deliver capsanthin for health benefits.

Display stability of fresh and thawed lamb supplemented with vitamin E or sprayed with an antioxidant borage seed extract

BACKGROUND

The commercialization of thawed lamb packaged in modified atmosphere and maintained on display could serve as an alternative capable of satisfying the requirements of both customers and distributors. However, previous studies have suggested that lipid oxidation may accelerate post-thawing because peroxidation occurs during frozen storage, thereby leading to rapid and severe secondary lipid oxidation. The addition of an antioxidant compound either in the lamb diet or in the packaged meat could resolve this problem. Therefore, the present study aimed to compare the effect of dietary vitamin E (1000 mg of dl-α-tocopheryl acetate per kg of basal diet) and the spraying of borage seed aqueous extract (10% p/v) on the quality of fresh and thawed lamb leg chops.

RESULTS

Both borage extract and vitamin E improved colour (as measured via instrumental and visual assessment of colour) and lipid stability (thiobarbituric acid reactive substances) of fresh and thawed lamb throughout display, although neither of them had any antimicrobial effect. Freezing/thawing accelerated bone marrow darkening and reduced redness but delayed microbial growth.

CONCLUSION

Both of these antioxidant strategies would be very profitable for the preservation of lamb meat, allowing thawed meat packaged in a modified atmosphere to be commercialized. However, additional studies should be carried out to determine how bone darkening in thawed chops can be avoided. © 2017 Society of Chemical Industry.

Antioxidant activity of resveratrol ester derivatives in food and biological model systems

Resveratrol (R) was lipophilized by esterification in order to facilitate its application in a wide range of products and to possibly enhance its bioactivity. Twelve resveratrol derivatives were prepared using acyl chlorides of different chain length (C3:0-C22:6) and their antioxidant activities assessed. While resveratrol showed the highest antioxidant activity in oil-in-water emulsion, its derivatives (RC6:0, RC8:0, RC10:0, RC12:0, RC16:0) showed better antioxidant activity in a bulk oil system. Resveratrol esters RC20:5n-3 (REPA) and RC22:6n-3 (RDHA) showed the highest antioxidant activity when added to ground meat. Meanwhile, resveratrol derivatives (RC3:0-RC14:0) had better hydrogen peroxide scavenging activity than resveratrol. All test compounds except resveratrol and REPA inhibited copper-induced LDL oxidation. Moreover, test compounds effectively inhibited hydroxyl radical induced DNA scission. These results suggest that resveratrol derivatives could potentially serve as functional food ingredients and supplements for health promotion and disease risk reduction.

Characterization of Barnyard Millet Starch Films Containing Borage Seed Oil

In this study, barnyard millet starch (BMS) was used to prepare edible films. Antioxidant activity was conferred to the BMS film by incorporating borage seed oil (BO). The physical, optical, and thermal properties as well as antioxidant activities of the films were evaluated. The incorporation of BO into the BMS films decreased the tensile strength from 9.46 to 4.69 MPa and increased the elongation at break of the films from 82.49% to 103.87%. Water vapor permeability, water solubility, and moisture content of the BMS films decreased with increasing BO concentration, whereas Hunter b value and opacity increased, L and a values of the films decreased. The BMS films containing BO exhibited antioxidant activity that increased proportionally with increased BO concentration. In particular, the BMS film with 1.0% BO exhibited the highest antioxidant activity and light barrier properties among the BMS films. Therefore, the BMS films with added BO can be used as an antioxidant packaging material.

The Endophytic Symbiont-Pseudomonas aeruginosa Stimulates the Antioxidant Activity and Growth of Achyranthes aspera L

A plant growth promoting bacterial endophyte designated as AL2-14B isolated from the leaves of Achyranthes aspera L. was identified as Pseudomonas aeruginosa based on its phenotypic and physiological features, and 16S rRNA gene sequence analysis. AL2-14B had plant growth stimulating attributes including siderophore and indole acetic acid release, inorganic phosphate solubilization, along with nitrogenase, ammonification, and protease activities. It also exhibited antifungal property against Rhizoctonia solani. The plantlets grown in germ-free condition were inoculated with AL2-14B and studied for the colonization of endophyte. Significant increase in population of AL2-14B between 3rd and 5th days after inoculation was recorded. The treatment of plants with endophytic P. aeruginosa AL2-14B increased nitrogen, phosphorus, potassium (NPK) contents in plant by 3.8, 12.59, and 19.15%, respectively. Significant enhancement of shoot and root length, dry leaf, dry shoot and dry root weight, and leaf surface area as compared to control (P < 0.05) was recorded in AL2-14B inoculated plants. The antioxidant activities increased in plants grown in germ-free conditions and inoculated with AL2-14B. The present study emphasizes on the role of diazotrophic endophyte P. aeruginosa AL2-14B in stimulating growth of A. aspera L. and improvement of its medicinal properties. Significant increase in growth and antioxidant content of P. aeruginosa AL2-14B treated plants suggests the possibility of an economical and eco-friendly mean of achieving antioxidants rich, healthier A. aspera plants.

Antioxidant properties of the red alga Asparagopsis taxiformis collected on the North West Algerian coast

The aim of the present study was to evaluate the total phenolic and lipid content, fatty acids profiles and in vitro antioxidant activities of aqueous and solvent extracts of the red seaweed Asparagopsis taxiformis, through six different investigations. The present study demonstrated that phenol contents (mg gallic acid/g dry weight) were highest in the aqueous and methanolic extracts, followed by the ethanolic, hydroethanolic and hydromethanolic extracts. The lowest phenol contents were identified in the three remaining extracts: Butanolic, petroleum ether and acetone extracts. Furthermore, the total lipid content of the algae powder amounted to 2.85% of dry weight. The fatty acid methyl ester profiles analysed by gas-liquid chromatography represented indicated that fatty acids comprised 91.0±0.3% of total algae lipids. The saturated to unsaturated fatty acid contents amounted to 23.2±0.1 and 67.9±0.4% respectively. C13:0 (tridecanoate), C15:0 (pentadecanoate) and C17:0 (heptadecanoate) represented 47.4% of the total saturated fatty acids. Notably, the two most abundant unsaturated fatty acids, C15:1 (pentadecenoate) and C18:2 (octadecadienoate) represented 13.4 and 11.4% respectively, of the total unsaturated fatty acid content. Furthermore, the results of the antioxidant screening performed at 1.0 mg/ml, revealed that aqueous and methanolic extracts exhibited higher inhibition against superoxide and nitric oxide radicals and excellent radical scavenging activity [with half maximal inhibitory concentration (IC₅₀) values 5.1 and 15.0 µg/ml, respectively], demonstrating improved antioxidant behavior when compared with standard ascorbic acid (which has an IC₅₀ value of 3.7 µg/ml). Scavenging activity of the aqueous and methanolic extracts exhibited a strong peroxidation inhibition against linoleic acid emulsion system at a concentration of 300 µg/ml in comparison to the butylated hydroxyltoluene. Although all the studied extracts exhibited ferric reducing power, the aqueous and methanolic extracts had greater hydrogen donating ability. By contrast, hydromethanolic, ethanolic, hydroethanolic, butanolic, acetone and petroleum ether extracts exhibited weak antioxidant behavior. The antioxidant activity of potent seaweed species identified in the current study means that as well as being used as a functional food, they may be developed as novel pharmaceutical compounds and may be used as anti-ageing agents.

Medicinal Plants from Northeastern Brazil against Alzheimer's Disease

Alzheimer's disease (AD) has been linked with oxidative stress, acetylcholine deficiency in the brain, and inflammatory processes. In the northeast region of Brazil, various plants are used to treat several diseases associated with these processes; then an antioxidant test was performed with those plants in a previous work and twelve species with higher antioxidant activity were selected for AChE inhibition evaluation. The phenolic compounds content was determined by Folin-Ciocalteu test and flavonoid content with AlCl3 reagent using UV-visible spectrophotometry. The antioxidant activity was assessed analyzing the inhibitory activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azinobis-3-ethylbenzothiazoline-6-sulfonate (ABTS) and by the β-carotene/linoleic acid system and acetylcholinesterase inhibition using qualitative and quantitative tests. The combination of better acetylcholinesterase inhibitory and antioxidant activities pointed out six species, in descending order, as the best potential sources of therapeutic agents against AD: Hancornia speciosa > Myracrodruon urundeuva > Copaifera langsdorffii > Stryphnodendron coriaceum > Psidium guajava > Mangifera indica. Besides, the phenolic compounds in the species probably contribute to these activities. However, further pharmacological studies to assess the specific applications of these plants against AD are required to confirm these results.

A simple and convenient method for the preparation of antioxidant peptides from walnut (Juglans regia L.) protein hydrolysates

Background

Walnut (Juglans regia L.), that belongs to the Juglandaceae family, is one of the nuts commonly found in Chinese diets. Researchers had obtained peptides from walnut protein hydrolysates, and these peptides exhibited the high antioxidant activities. The objective of this study was to develop a simple and convenient method for a facile and reproducible preparation of antioxidant peptides from walnut protein hydrolysates.

Results

Walnut proteins were extracted from walnut kernels using continuous countercurrent extraction process, and were separately hydrolyzed with six types of proteases (neutrase, papain, bromelain, alcalase, pepsin, and pancreatin). Then, hydrolysates were purified by ultrafiltration. The yields and purity of the peptides prepared using neutrase and papain were 16 and 81 % at least, respectively, higher than others, and had low molecular weight, 99 % of which were less than 1500 Da. Furthermore, the bioassay indicated that the two peptides exhibited the high antioxidant activities in the DPPH (IC₅₀ values: 59.40 and 31.02 µg/mL, respectively), ABTS (IC₅₀ values: 80.36 and 62.22 µg/mL, respectively), and superoxide radical scavenging assay (IC₅₀ values: 107.47 and 80.00 µg/mL, respectively).

Conclusions

The method combines the advantages of generality, rapidity, simplicity, and is useful for the mass production of walnut peptides.Graphical Abstract

Bioactivity, stability and phenolic characterization of Filipendula ulmaria (L.) Maxim

The purpose of the present study was to evaluate the antioxidant and antimicrobial potential of Filipendula ulmaria (L.) Maxim. methanolic extracts, their stabilities under different pH and thermal conditions and in vitro digestibility. The results showed a considerable content of phenolic compounds in the extracts, especially total phenolic acids (47.47 mg CAE g(-1)) and flavonoids (45.47 mg RUE g(-1)) in aerial parts. HPLC analysis indicated the presence of spiraeoside in the aerial part extract. The extracts revealed an interesting antimicrobial effect against the tested microorganisms, especially bacteria E. coli and E. faecalis (MIC 0.156-0.625 mg mL(-1)), and fungi P. cyclopium and F. oxysporum (MIC 2.5-5 mg mL(-1)). The extracts exerted high antioxidant activities, particularly the root extract, paralleled by their considerable activities against the lipid oxidation process. The results of this study suggest that both extracts potentially could be functional food ingredients considering their good antioxidant and antimicrobial activities, and stability under different conditions.

A hexameric peptide purified from Styela plicata protects against free radical-induced oxidative stress in cells and zebrafish model

To prepare antioxidative peptide from Styela plicata, nine proteases were employed for enzymatic hydrolysis, and the antioxidative activities of the hydrolysates were investigated using an electron spin resonance (ESR) spectrometer.

Optimized enzymatic colorimetric assay for determination of hydrogen peroxide (H2O2) scavenging activity of plant extracts

The classical method to determine hydrogen peroxide (H₂O₂) scavenging activity of plant extracts is evaluated by measuring the disappearance of H₂O₂ at a wavelength of 230 nm. Since this method suffers from the interference of phenolics having strong absorption in the UV region, a simple and rapid colorimetric assay was developed where plant extracts are introduced to H₂O₂, phenol and 4-aminoantipyrine reaction system in the presence of horseradish peroxidase (HRP). This reaction yields a quinoneimine chromogen which can be measured at 504 nm. Decrease in the colour intensity reflects the H₂O₂ scavenged by the plant material.

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Optimum conditions determined for this assay were 30 min reaction time, 37 °C, pH 7, enzyme concentration of 1 U/ml and H₂O₂ concentration of 0.7 mM. The limit of detection (LOD) and limit of quantitation (LOQ) were 136 μM and 411 μM, respectively.

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Half maximal effective concentration required to scavenge 50% of H₂O₂ in the system (EC₅₀ value) calculated for several plant extracts and standard antioxidants resulted in coefficient of variance (CV%) of the EC₅₀ values less than 3.0% and correlation coefficient values (R²) > 0.95 for all dose response curves obtained.

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This method is convenient and very precise which is suitable for the rapid quantification of H₂O₂ scavenging ability of standard antioxidants and natural antioxidants present in plant extracts.

Antioxidant potential of date (Phoenix dactylifera L.) seed protein hydrolysates and carnosine in food and biological systems

Date seed protein hydrolysates were evaluated for antioxidant activity as well as solubility and water-holding capacity in food and biological model systems. Date seed protein hydrolysates as well as carnosine exhibited >80% of solubility over a pH range of 2-12. The hydrolysates and carnosine at 0.5% (w/w) were also found to be effective in enhancing water-holding capacity and cooking yield in a fish model system, which was nearly similar to sodium tripolyphosphate (STPP; 0.3%, w/w). Incorporation of hydrolysates (200 ppm) in fish model systems resulted in the highest inhibition (30%) of oxidation in comparison to butylated hydroxytoluene (BHT; 9%). In addition, hydrolysates and carnosine inhibited β-carotene oxidation by 75%. The hydrolysates (0.1 mg/mL) inhibited LDL cholesterol oxidation by 60%, whereas carnosine inhibited oxidation by 80% after 12 h of incubation. Additionally, hydrolysates and carnosine effectively inhibited hydroxyl (6 mg/mL) and peroxyl (0.1 mg/mL) radical-induced DNA scission. Therefore, date seed protein hydrolysates could be used as a potential functional food ingredient for health promotion.