Ferrous Ion Chelating Activity Research Articles

Chemodiversity, Biological Activities and Molecular Docking Studies of Leptadenia pyrotechnica (Forssk.) Decne: A Comprehensive Approach to Validate Its Medicinal Use.

Leptadenia pyrotechnica (Forssk.) Decne is growing in Cholistan desert, and is known for its laxative, analgesic, anabolic and astringent, antioxidant, anti-inflammatory, antibacterial, antitumor, hypolipidemic and antiatherosclerotic properties. The present study disclosed the metabolic picture of L. pyrotechnica and validates its folk uses. LP-H fraction constitute 25.79±0.11 mgGAE/g extract and 20.64±0.33 mgRE/g extract of phenolic and flavonoid content, respectively, followed by LP-E (23.15±0.33 mgGAE/g extract and 19.40±0.13 mgRE/g extract), however, LP-E exhibited the highest free radical scavenging (DPPH: 21.05±0.45mgTE/g and ABTS: 68.12±0.53 mgTE/g) and metal reducing (FRAP: 44.93±1.66, CUPRAC: 117.42±1.28 mgTE/g, respectively) activities. The total antioxidant capacity in Phosphomolybdenum assay (1.52±0.14 mmolTE/g) and ferrous ion chelating (11.57±0.29 mgEDTAE/g) activities were observed highest for LP-H extract. In cholinesterase's inhibitory assays, the LP-E and LP-W extracts exhibited inhibitory values as 2.43 and 2.40±0.07 mgGALAE/g extract, respectively against AChE, while against BChE the LP-H displayed the highest value as 5.98±0.44 mgGALAE/g extract. The LP-H fraction also showed the highest inhibition potential (7.72±0.14 mmol ACAE/g and 0.55±0.01 mmol ACAE/g, respectively) against α-glucosidase and α-amylase enzymes, while, in tyrosinase inhibitory assay, all the fractions exhibited significant activities in the range of 59.35±0.29 to 55.18±0.49 mgKAE/g extract. RP-UHPLC/MS analysis of LP-M disclosed the presence of 57 metabolites of various classes. A multivariate analysis and molecular docking study was also carried out to establish relationships between the metabolites and the biological activities, which finally validate the use of L. pyrotechnica as herbal medicine or component nutraceutical, food and cosmetic industry.

Phytochemical Screening, Antioxidant, Antiulcer, Anti-Inflammatory and Analgesic Activity of the Aqueous Extract of Angelica archangelica

The objective of this study is to evaluate the antioxidant, antiulcer, anti-inflammatory and analgesic activity of the aqueous extract of Angelica archangelica L., a medicinal plant of the traditional pharmacopoeia of Algeria. The aqueous extract showed a large amount of total polyphenols, tannins, chlorophyll a, b, carotenoids and a small amount of flavonoids with values of 80.16±14.3 mg EAG/g of extract, 3.12±2.01 mg EQ/g of extract, 226.10±4.50 mg EAT/g of extract, 6.10±50.62, 12.00±31.53 and 1.78±0.40 μg/mL respectively. In addition, the aqueous extract of A. archangelica showed a high ability to trap DPPH radical in with IC50 at 16.9±2.03μg/mL. However, the aqueous extract has a great protective effect against β-carotene degradation at 91.98±0.64% after 24 hours and significant ferrous ion chelation activity at46.2 ±1.53µg/mL. Furthermore, the anti-inflammatory activity was studied according to the protein denaturation inhibition method and, according to the results obtained, the extract of A. archangelica at concentrations of 250, 500 μg/mL and 1 mg/mL have ahigh antiinflammatory activity whose inhibition percentages are 78.85±5.31%, 86.65±2.70% and 89.89±0.58% respectively. The analgesic effect of the aqueous extract of A. archangelica, showed that the concentration 400 mg/mL has a greet abdominal cramps inhibitory effect in comparison with the concentration 200 mg/mL with a percentage of 98.28%. The antiulcer effect of the aqueous extract of A. archangelica was evaluated by the 70% ethanol-induced ulcer test. The results obtained reveal that the aqueous extract 200 and 400 mg/mL exerted a considerable effect of protecting the stomach at 86.55±3.51% and 82.82±2.18% respectively.

Two Onosma Species (Onosma microcarpum and O. nana) as an Alternative Source of Multifunctional Agents: Biological and Phytochemical Evaluation

Phytochemicals have significant biological effects. This study aimed to investigate the chemical composition, antioxidant and inhibitory activities of methanol (MeOH) extracts obtained from the aerial parts of Onosma microcarpum DC. and O. nana DC. on enzymes that play a critical role in digestive and cholinergic systems and melanogenesis process. The chemical compositions of the extracts were determined by using spectrophotometric and chromatographic methods. The biological activities of the extracts were determined by using antioxidant and enzyme inhibitory test systems. According to spectrophotometric analysis, both phenolic and flavonoid concentrations of O. nana were found higher than O. microcarpum (44.63 mg GAEs/g and 27.86 mg QEs/g, respectively). Chromatographic analysis shows that O. nana contains a high amount of hesperidin (53412.37 µg/g). In comparison, O. microcarpum has rosmarinic acid (13181.91 µg/g), apigenin 7-glucoside (11693.97 µg/g), luteolin 7 -glucoside (8632.03 µg/g) and pinoresinol (1014.26 µg/g) as the main compounds. In the ferrous ion chelating activity test, extracts exhibited almost similar activities. In contrast, radical scavenging (DPPH and ABTS), reducing power (CUPRAC and FRAP), and phosphomolybdenum tests resulted in the superiority of O. nana (229.98, 243.58, 327.46, 189.69, and 783.14, mg TEs/g, respectively). In the α-amylase inhibitory activity test, O. microcarpum showed higher activity (406.31 mg ACEs/g). In comparison, α-glucosidase (958.23 mg ACEs/g) and acetylcholinesterase (AChE) (2.80 mg GALAEs/g), butyrylcholinesterase (BChE) (2.59 mg GALAEs/g), and tyrosinase (200.43 mg KAEs/g) inhibitory activity of O. nana was found to be stronger than the other sample. (4) Conclusions: The chemical compositions and biological activities of the mentioned Onosma species were brought to the literature for the first time with this study. It is thought that O. nana can be an alternative source of phytochemicals in the food, pharmaceutical, and cosmetic industries due to its biological activity potential.

Antioxidant Properties of Fermented Camel Milk Prepared Using Different Microbial Cultures

This study investigated the effect of using different combinations of commercial starter culture and lactobacilli strains on the antioxidant properties of fermented camel milk for 14 days. The bacterial strains included Lb. casei subsp. casei B-1922, Lb. paracasei subsp. paracasei B-4560, Lb. rhamnosus B-442 and Lb. rhamnosus B-1445. The antioxidant activity of fermented milk was estimated using DPPH radical scavenging activity, ferrous ion chelating activity (FCA) and ferric reducing power assays. The total phenolic content (TPC), titratable acidity, proteolysis degree and sensory acceptability of samples were also evaluated. The results showed that all the studied parameters were affected by both the type of starter culture and storage. Samples containing the commercial starter and Lb. rhamnosus B-1445 had the highest DPPH radical scavenging activity and TPC throughout storage. Fermented milks prepared using the commercial starter and Lb. rhamnosus B-442 or Lb. paracasei retained their high FCA and reducing power throughout storage compared to the other samples. Fermented milk containing the commercial starter and Lb. casei showed the lowest antioxidant activity. The DPPH scavenging activity for all fermented milks decreased sharply during storage, while the change in FCA, reducing power and TPC differed among the samples during storage. The highest acidity was observed in the samples containing the commercial starter and Lb. paracasei, while fermented milk prepared using commercial starter and Lb. rhamnosus B-1445 had the lowest acidity. Samples containing the commercial starter and Lb. casei had the greatest proteolysis during the first week of storage, while samples containing the commercial starter and Lb. rhamnosus B-1445 had the highest proteolysis on day 14. Fermented milks with commercial starter and Lb. rhamnosus B-1445 or Lb. paracasei were the most acceptable products, while samples containing the commercial starter and Lb. casei were less acceptable.

Floral origin, Antioxidant and Antimicrobial Activity of Some Floral Honey

The study was planned to assess botanic origin, antioxidant power, antimicrobial activity and physicochemical properties of four honey samples were collected in Turkey. The melissopalynologic results revealed that sample 1 and 2 are polyfloral, and others are unifloral. Total content of phenolic (116.47-1711.13 mg GAE/100 g) and flavonoids (1.46 - 27.25 mg CAE/100 g) were analysed, and the antioxidant activities measured by ferrous ion chelating activity (FICA) (71.32-93.35%), hydrogen peroxide scavenging activity (HPSA) (SC50: 217.8-1238.39 µg/mL), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging (SC50: 20.15-27.14 µg/mL), 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity (SC50: 22.93-308.17 µg/mL) and ferric reducing antioxidant power (FRAP) (71.03-99.54 %) differed notably. For comparison of the samples, butylated hydroxy anisole (BHA), rutin (RUT) and trolox (TRO) were used as standard antioxidant compounds. According to these results, samples showed more efficient antioxidant activity than TRO except for ABTS assay. Also, Sample 1 and 4 have higher FICA activity and Sample 2 and 3 demonstrated more FRAP activity than standards. The minimal inhibitory concentrations (MICs) and agar diffusion assays of honey samples against Staphylococcus aureus and Escherichia coli showed that these samples was the most effective in inhibition of their growth.

Phenolic profile, antioxidant and enzyme inhibitory activity of the ethyl acetate, methanol and water extracts of Capparis spinosa L.

In this study, it was aimed to determine the phytochemical compositions and biological activities of ethyl acetate (EtOAc), methanol (MeOH) and water extracts obtained from the aerial parts of Capparis spinosa L. As a result of spectrophotometric analyzes, MeOH extract was found to be richer in terms of both phenolics and flavonoids compared to other extracts [81.45 mg GAEs (gallic acid equivalent)/g and 36.57 mg RE (rutin equivalent)s/g, respectively], while chromatographic analyzes showed that the extract in question contains a significant amount of hepseridin (72927.48 µg/g), quercetin (1335.88 µg/g), hyperoside (1227.73 µg/g), and 4-hydroxybenzoic acid (924.08 µg/g). Phosphomolybdenum, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging, Cupric Reducing Antioxidant Power (CUPRAC) and Ferric Reducing Antioxidant Power (FRAP) reducing and ferrous ion chelating activity tests resulted in superiority of MeOH extract [371.0, 44.93, 56.46, 91.77, 52.61 mg TEs (trolox equivalent)/g and 14.85 mg EDTAEs/g, respectively]. On the other hand, EtOAc extract exhibited higher activity than other extracts in acetylcholinesterase (AChE), butyrylcholinesterase (BChE), α-amylase, and α-glucosidase inhibitory activity tests [3.29, 2.12 mg GALAEs (galanthamine equivalent)/g, 541.01 and 1584.20 mg ACEs (acarbose equivalent)/g, respectively]. The tyrosinase inhibitory activity test resulted in the superiority of MeOH extract [41.90 mg KAEs (kojic acid equivalent)/g]. A strong correlation was determined between the phenolic and flavonoid contents of the extracts and their antioxidant activities.

Antibacterial Activity, Antioxidant Potential and Stigmasterol Isolation from Laggera aurita Linn (Asteraceae)

The study was aimed at the in-vitro investigation of the antibacterial activity, antioxidant potential and bioactive compound isolation from ethyl acetate crude fraction of Laggera aurita (L. aurita) Linn. The crude fraction was tested against five gram negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Salmonella typhi, Proteus mirabilis) and three gram positive bacteria (Staphylococcus aureus, Enterococcus faecalis and Bacillus subtilis) using macro dilution technique. The antioxidant potentials were evaluated using two different but complementary methods namely ferrous ion chelating activity (FICA) and ferric reducing antioxidant potential (FRAP). Phytocompound isolation was carried out on low pressure open column chromatography. The crude fraction displayed moderate to significant activity against all tested bacteria exhibiting both bacteriostatic and bactericidal effects. The crude fraction showed Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) in the range of 62.50-250 µg/mL and 125-1000 µg/mL respectively. The crude fraction was bactericidal to all tested pathogens except E. coli. The fifty percent effective concentration (EC50) of EDTA standard and the ethyl acetate fraction were obtained as 10.87 μg/mL and 25.77 μg/mL respectively. Similarly the FRAP determinations for ascorbic acid and ethyl acetate fraction yielded 153.63 and 134.40 Fe2+ Equivalent per g of fraction indicating 80.06% and 70.61% FRAP units respectively. The isolated phytocompound coded LAE was obtained as a white crystalline solid with melting point of 136‐138°C and Rf of 0.56 in hexane: ethylacetate (6:4). The isolated compound was identified by spectroscopic data analysis from FT-IR, GC-MS, 1D and 2D NMR and in comparison with literature. The compound was identified as stigmasterol. The observed significant antibacterial and antioxidant properties demonstrated by L. aurita in this study validate its widespread use in traditional medicine. Therefore the study had shown that L. aurita contains bioactive principles and may serve as a source for potential antibacterial and oxidative stress therapeutic agents.

Novel styrax liquidus loaded chitosan/polyvinyl alcohol cryogels with antioxidant and antimicrobial properties

AbstractIn this study, a novel cryogel scaffold loaded with styrax liquidus gum exuded from trank of Anatolian sweetgum (Liquidambar orientalis Mill.), with antimicrobial and antioxidant properties was developed for potential tissue engineering applications. For this purpose, different ratios of styrax incorporated chitosan/polyvinyl alcohol composite scaffolds were fabricated using cryotropic gelation method. The effect of styrax incorporation onto the cryogel network was evaluated using morphological and physico‐chemical analyzes. The characterized cryogels were also investigated in detail for their antioxidant activity, anti‐biofilm, antimicrobial, and DNA cleavage properties. The styrax incorporated cryogels can be candidate biomaterials for tissue engineering applications, in particular for antimicrobial systems due to their ferrous ion chelating activity and high antioxidant, anti‐biofilm, and antimicrobial properties.

Determination and Characterization of Phenolic Compounds from Australia-Grown Sweet Cherries (Prunus avium L.) and Their Potential Antioxidant Properties

Sweet cherries (Prunus avium L.) are popular fruits around the world with a high nutritional value and abundant phenolic compounds. Phenolic compounds of cherries contribute to positive health benefits. This study aimed at determining the phenolic content and antioxidant activities in four Australian-grown sweet cherry cultivars, including Bing, Ron’s, Merchant, and Lapins, as well as the identification of individual phenolic compounds with liquid chromatography–electrospray ionization–quantum time-of-flight–mass spectrometry (LC–ESI–QTOF–MS2). Lapins exhibits the highest total phenolic content (TPC) value (1.73 ± 0.90 mg gallic acid equivalents (GAE)/g) while Ron’s exhibits the highest total flavonoid content (TFC) value (0.51 ± 0.02 mg QE/g). In 2,2′-azinobis-(3-ethylbenzo-thiazoline-6-sulfonic acid) (ABTS), reducing power assay (RPA), and total antioxidant content (TAC) assays, Merchant exhibited the highest values (0.51 ± 0.07, 1.74 ± 0.04, and 2.79 ± 0.09 mg AAE/g, respectively) and almost showed the highest antioxidant activity. Ron’s presented the highest value (1.21 ± 0.09 mg EDTA/g) in ferrous ion-chelating activity (FICA) assay and exhibits the strongest metal chelating ability. The correlation between phenolic contents and antioxidant assays was observed. In the LC–ESI–QTOF–MS2 analysis, a total of 43 phenolic compounds has been detected in four sweet cherry cultivars, including 11 phenolic acids, 25 flavonoids, 5 other phenolic compounds, 1 lignan, and 1 stilbene. Venn graph showed that Lapins has the greatest number of unique compounds. Our study shows the presence of phenolic acids and provides information to be utilized as an ingredient in food, pharmaceutical, and nutraceutical industries.

A mutant of seawater Arthrospira platensis with high polysaccharides production induced by space environment and its application potential

To improve the yields of specific value-added compounds from Arthrospira platensis, one generally accepted method is to obtain mutant strains with increased target component content and growth rate. In the present study, mutation breeding of seawater A. platensis SCSIO-44012 (the wild type strain, hereafter WT) through space-flight carriage by Shijian-10 satellite was carried out. After returning to earth, 183 single filaments were picked out, 43 of which survived. During the following consecutive subcultures, one out of the 43 mutant strains, named A. platensis SCSIO-44012-H11 (hereafter H11), showed stable advantages in high levels of polysaccharides production. The biomass yield, total sugar content, and total sugar productivity of H11 remained stable at 0.88 g L−1, 24.82% DW, and 21.78 mg L−1 d−1, respectively, from the 10th to 35th generations of subculture, which were 8.6%, 62.26%, and 73.68%, respectively, higher than that of WT. The biochemical compositions of polysaccharide extracts (PSE) from H11 and WT also exhibited significant differences. The total sugar content of H11 PSE reached 55.37%, 2.49 times as much as that of WT PSE. The PSE from H11 was enriched in the component cutting off 100 kDa, accounting for 89.32% of the total polysaccharides, whereas WT PSE was mainly composed of the component with a molecular weight between 10 kDa and 50 kDa. The predominant monosaccharide of H11 PSE was glucose, followed by rhamnose, which accounted for 84.53% and 8.13% of the total monosaccharides, respectively. By comparison, glucose and rhamnose occupied 27.33% and 35.41%, respectively, in PSE from WT. Furthermore, the PSE from H11 showed strong ferrous ion-chelating activity and moisture retention capacity. These results indicated the feasibility of H11 as a polysaccharides feedstock applied in cosmetics, nutraceuticals, and medicines.

Antioxidant, Anti-inflammatory, and Analgesic Activities of Alcoholic Extracts of Ephedra nebrodensis From Eastern Algeria

Ephedra nebrodensis (Ephedraceae) presents a wide range of biological activities. It is used to treat respiratory problems and hepatic pathologies in traditional medicine. The aim of this study is to evaluate the antioxidant, in vitro and in vivo anti-inflammatory and analgesic properties of two hydro-alcoholic extracts of E. nebrodensis in mice. The antioxidant capacity of hydro-methanolic (HM) and hydro-ethanolic (HE) extracts of E. nebrodensis was evaluated via assays of their superoxide radical scavenging capacity and ferrous ion chelating activity. The in vitro anti-inflammatory activity of the extracts (5, 10, and 20 mg/kg) was also determined using the bovine serum albumin denaturation test. Croton oil-induced ear edema was then employed to evaluate the in vivo anti-inflammatory effect of the extracts (200 and 400 mg/kg). Finally, the analgesic activity of the extracts (200 and 400 mg/kg) was determined by the acetic acid-induced torsion test. The hydro-alcoholic extracts of E. nebrodensis present significant antioxidant activity. The HE and HM could inhibit protein denaturation by 82.99%±20.21% and 56.25%±2.12%, respectively. The extracts (HM and HE) also show strong anti-inflammatory effects in vivo and could reduce ear edema by 70.37%±2.00% and 72.22%±1.94%, respectively. The HM extract (72.51%±2.43%) demonstrates greater pain inhibitory effects than HE (70.76%±2.58%). The hydro-alcoholic extracts of E. nebrodensis produce antioxidant, anti-inflammatory, and analgesic effects. These results confirm the traditional use of the herb in the treatment of various diseases.

Development and Evaluation of Thermosensitive Hydrogels with Binary Mixture of Scutellariae baicalensis radix Extract and Chitosan for Periodontal Diseases Treatment.

Scutellaria baicalensis root displays anti-inflammatory and antibacterial properties due to the presence of flavonoids, particularly baicalin, baicalein, and wogonin. Our work aimed at developing thermosensitive hydrogels containing a binary mixture of S. baicalensis radix lyophilized extract and chitosan as a novel approach for periodontal diseases treatment. Two types of chitosan were employed in preliminary studies on binary mixtures with S. baicalensis radix lyophilized extract standardized for baicalin, baicalein, and wogonin. Thermosensitive hydrogels were prepared of poloxamer 407, alginate sodium, and cellulose derivatives and evaluated in terms of rheological and mucoadhesive behavior. The presence of chitosan altered the release profile of active compounds but did not affect their in vitro permeation behavior in PAMPA assay. The synergistic effects of S. baicalensis radix lyophilized extract and chitosan toward ferrous ion-chelating activity, inhibition of hyaluronidase, and pathogen growth were observed. The thermosensitive gelling system showed shear-thinning properties, gelation temperature between 25 and 27 °C, and favorable mucoadhesiveness in contact with porcine buccal mucosa, which was enhanced in the presence of binary mixture of S. baicalensis radix extract and chitosan. The release tests showed that baicalin and baicalein were liberated in a prolonged manner with a fast onset from hydrogel formulations.

Differential effects of biogenic and chemically synthesized silver-nanoparticles application on physiological traits, antioxidative status and californidine content in California poppy (Eschscholzia californica Cham)

Silver nanoparticles (AgNPs) of both biologically and chemically origins trigger various physiological and metabolic processes through interaction with plant cells, exerting positive, negative and inconsequential effects. However, their impacts on plant systems must be critically investigated to guarantee their safe application in food chain. In this study, the effects of chemically synthesized (synthetic) AgNPs (sAgNPs) and biologically synthesized (biogenic) AgNPs (bAgNPs) on physiological and biochemical features of Eschscholzia californica Cham were evaluated at different concentrations (0, 10, 25, 50 and 100 mg L−1). Plants exposed to bAgNPs (at 10 and 25 mg L−1) and sAgNPs (at 10 mg L−1) displayed relatively uniform deposition of AgNPs on leaf surface, however, the higher concentration (100 mg L−1) was accompanied by aggregation of AgNPs, resulting in anatomical and physiological disorders. Foliar application of both AgNPs at lower concentrations resulted in significant (P < 0.01) improve in the content of photosynthetic pigments (chlorophylls a, b, a+b, and carotenoids) and total phenolics over the control in a dose-related manner. Leaf relative water content decreased steadily with increasing both sAgNPs and bAgNPs concentrations-with sAgNPs being more inhibitive. Both types of AgNPs at 100 mg L−1 significantly (P < 0.05) increased electrolyte leakage index, level of lipid peroxidation product (malondialdehyde), and leaf soluble sugar content when compared to controls. No significant difference was found on cell membrane stability index among the plants exposed to bAgNPs and sAgNPs at the lowest concentration over the control. Californidine content was significantly (P < 0.01, by 45.1%) increased upon all the bAgNPs treatments (with a peak at 25 mg L−1) relative to control. The obtained extracts from plants treated with bAgNPs at lower concentrations revealed a significant induction of antioxidant capacity (based on DPPH˙ free radical scavenging and ferrous ions-chelating activities) with lower IC50 values compared to the other treatments. Conclusively, bAgNPs at lower concentrations are potent elicitors of pharmaceutically active compounds biosynthesis, which enhance physiological efficiency of E. californica, but at higher concentrations bAgNPs are equally toxic as sAgNPs.

In vitro antioxidant properties of 2-(4-(2-hydroxybenzylideneamino)benzylideneamino)benzoic acid

In recent years, it has attracted great attention to determine and appraise synthetic antioxidants with high free radical scavenging capacity associated with various disorders. Because synthetic antioxidants are widely used in place of native antioxidants as they are influential and less expensive. In this study, the antioxidant activity of the newly synthesized asymmetric diimine Schiff base was determined by using DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging, ferrous ion chelation (FIC) activity and total antioxidant activity (Phosphomolybdenum assay) methods. The effective concentration (IC50) values were calculated for the Schiff base and standards. According to the results of DPPH radical scavenging, ferrous ion chelation and total antioxidant methods, Schiff base showed a well antioxidant activity. It was determined that Schiff base is reactive towards DPPH radicals (IC50, 180.0 μM) and especially Fe+2 ions (IC50, 76.3 μM). It was also found that it actively reduces the Mo(VI) ion to the Mo(V) form (IC50, 121.5 μM). The our results indicate Schiff base, may be a fine candidate as a source of synthetic antioxidants and possibly strong drug.

Influence of Seasonal and Yearly Variation on Phenolic Profiles, Caffeine, and Antioxidant Activities of Green Tea (Camellia sinensis (L.) Kuntze) from Azores

This study compares the antioxidant properties (RSADPPH–DPPH radical scavenging activity, FRAP–ferric reducing activity power, and FIC–ferrous ion-chelating activity), the total phenolics (TP), total flavonoids (TF), and catechin profiles, as well as the caffeine content of Azorean Camellia sinensis green tea collected in seasons of two different years. The RSADPPH showed some variation between 2019 and 2020, and presented, in general, better results in 2020 as well as during the summer seasons. The FRAP was also noted to be at its highest in July and August of the two investigated years (6.64 and 6.40 µg/mL in 2019 and 5.85 and 5.46 µg/mL in 2020). According to FIC activity, the August 2019 sample exhibited the highest value (76.18%). The TP varied between 291.14 and 326.93 mg gallic acid equivalents (GAE)/g of dried extract (DE) in 2019 and between 300.25 and 320.58 mg GAE/g DE in 2020. Concerning the TF, the values varied between 51.85 and 67.93 mg rutin equivalents (RE)/g DE in 2019 and between 50.27 and 69.57 mg RE/g DE in 2020. Epicatechins derivatives, determined by HPLC, presented higher values in all samples from 2020 compared to 2019, and the same was observed for esterified catechins. The epigallocatechin-3-gallate content was also higher in all samples from 2020 (214.52–240.16 mg/g DE) compared to 2019 (140.91–210.83 mg/g DE). Regarding caffeine content (12.86–20.45 mg/g DE in 2019 and 13.19–29.35 mg/g DE in 2020), the samples from April and June exhibited similar values in both years. In general, green tea samples exhibited better results in 2020 than in 2019, with the exception of FIC activity, while the varied TP and TF contents in certain months reflect the impact of climatic variation on tea quality.

Antioxidant activity and functional properties of grey mullet (Mugil cephalus) protein hydrolysates

Grey mullet protein hydrolysate possessed high antioxidant activity and was prepared using neutrase. The hydrolysis conditions were optimised by the response surface methodology (RSM): enzyme to substrate ratio 5.8:1 (U of enzyme/mg of substrate), pH 7.3, 51°C, and 3.5 h. The hydrolysate obtained under the optimal conditions (HGM) possessed superior radical scavenging activity (IC50 values: 0.786 mg/mL for DPPH; 1.294 mg/mL for superoxide anion radical) to that of unhydrolysed grey mullet protein (GM). HGM also possessed better ferric-reducing power and higher ferrous ion-chelating activity. Electrophoretic analysis indicated that HGM mainly consisted of peptides with molecular weights below 10 kDa. The amino acid composition indicated a high nutritional value for HGM. The solubility, foamability, and emulsion activity index of HGM were improved as compared to those of GM. These results indicated that HGM has potential as a bioactive ingredient in the formulation of functional foods.

Draba cemileae (Karaer): Phytochemical composition, antioxidant and enzyme inhibitory activity

Plant polyphenols have always attracted the attention of researchers with their excellent biological activity potentials. In this study, roots, leaves and seeds of Draba cemileae (Karaer) were evaluated for their chemical compositions and biological activities. Spectrophotometric analysis showed that phenolics and flavonoids were present in high quantities in leaf and seed extracts (22.84 mg GAEs/g and 23.32 mg REs/g, respectively). Chromatographic analysis showed that the p-hydroxybenzoic acid and chlorogenic acid contents of the extracts were significantly high. The seed extract also contained 550 mg/g of rosmarinic acid. While the leaf extract showed high activity in phosphomolybdenum, CUPRAC, FRAP and ferrous ion chelating activity tests (0.88, 2.23, 1.73 and 3.68 mg/ml, respectively), DPPH and ABTS scavenging activity tests resulted in the superiority of the seed extract (3.75 and 2.53 mg/ml, respectively). The leaf extract also showed the highest activity in α-amylase and tyrosinase inhibitory activity tests (1.78 and 4.99 mg/ml, respectively). On the other hand, the seed extract exhibited higher activity than the others in α-glucosidase, AChE and BChE inhibitory activity tests (7.14, 1.13 and 5.11 mg/ml, respectively). Correlation coefficients between the composition and the biological activities were over 0.9. It was concluded that D. cemileae could be a new and effective source of antioxidant and enzyme inhibitory phytochemicals in medicine, food and cosmetics industries.

Phytochemical Composition, Antioxidant, and Enzyme Inhibition Activities of Methanolic Extracts of Two Endemic Onosma Species.

Onosma species have been used as a dye for hundreds of years due to their dark red pigments. These species have also been used by mankind in the treatment of various diseases since ancient times. This work analyzed the phytochemical composition in methanol extract of two endemic Onosma species (O. lycaonica and O. papillosa). Methanolic extract of these species varied in the content of flavonoids and phenolics. The flavonoids were found higher in O. papillosa [32.9 ± 0.3 mg QEs (quercetin equivalent)/g extracts] while the phenolics were higher in O. lycaonica [43.5 ± 1.5 mg GAEs (gallic acid equivalent)/g extracts]. ESI-MS/MS (electrospray ionization-mass spectrometry) revealed the presence of 25 compounds in O. lycaonica and 24 compounds in O. papillosa. The former was richer than the latter for apigenin, luteolin, eriodictyol, pinoresinol, apigenin 7-glucoside, rosmarinic acid, luteolin 7-glucoside, ferulic acid, vanillin, caffeic acid, 4-hydroxybenzoic acid, (+)-catechin3,4-dihydroxyphenylacetic acid. The O. papillosa exhibited low EC50 (1.90 ± 0.07 mg/mL) which indicated its strong phosphomolybdenum scavenging activity as compared to O. lycaonica. However, the O. lycaonica showed low IC50 or EC50 for 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+), cupric reducing antioxidant power (CUPRAC), ferric reducing antioxidant power (FRAP) and ferrous ion chelating activity, as compared to O. papillosa. The results proved the presence of potent antioxidant compounds in O. lycaonica. Further, the plant extracts significantly varied for enzyme inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), but the plant extracts did not significantly differ for inhibition of α-glucosidase, α-amylase, and tyrosinase. Onosma species deserve further research towards developing novel drugs to treat oxidative diseases.

Micronization and coating of bioflavonoids extracted from Citrus sinensis L. peels to preparation of sustained release pellets using supercritical technique

Bioflavonoids such as hesperidin and hesperetin as anticancer and antioxidant agents are widely used in the formulation of many herbal drugs. Recently, promising evidence for the prevention and treatment of COVID 19 using these compounds has been reported. Unfortunately, these compounds are often insoluble in aqueous media and have low stability in gastric acid environment. These factors reduced the bioavailability of related oral dosage forms in digestive system. Reduction of particle size and controlled release delivery system can decline the mentioned problems. In the presented research, extraction of bioflavonoids from Citrus sinensis L. (sweet orange) peels was performed using supercritical carbon dioxide. Experimental central composite design was employed for determination of optimal conditions. Qualification analysis was performed using LC–MS, and hesperidin and hesperetin were identified in herbal extract. Micronization and coating of the flavonoids nanoparticles on sugar spheres have been performed using an inhouse developed supercritical technique. Characterization of coated nanoparticles was done using FESEM and ImageJ software. The in vitro antioxidant activity of coated samples was investigated by ferrous ion chelating activity. According to the extraction results, concentration of ethanol as organic co-solvent has the greatest effect on the extraction yield. Analysis of FESEM images illustrated that nanoparticles of extract components with particle size distribution of 5–100 nm were coated successfully. The solubility and antioxidant activity of nanoparticles in aqueous media have increased significantly compared to original form. This process led to increasing dissolution rate and improving the oral bioavailability of flavonoids.Graphical abstract

Investigation of the antifouling properties of polyethersulfone ultrafiltration membranes by blending of boron nitride quantum dots

This study aims to investigate the modification of polyethersulfone (PES) membrane with boron nitride quantum dots (BNQD) for improving the antifouling performance. The composite membranes were synthesized by blending different amounts of BNQD (0.50, 1.00, and 2.00 wt.%) into PES with the non-solvent induced phase separation (NIPS) method. UV–vis absorption, X-ray diffraction (XRD), and transmission electron microscopy (TEM) were used to characterize BNQD. Moreover, porosity, pore size, contact angle, permeability, bovine serum albumin (BSA) rejection, and antifouling properties were determined for composite membranes. The enhanced biological activity of BNQD was investigated based on antioxidant, antimicrobial, anti-biofilm, bacterial viability inhibition, and DNA cleavage studies. The BNQD showed 19.35 % DPPH radical scavenging activity and 76.45 % ferrous ion chelating activity at 500 mg/L. They also exhibited good chemical nuclease activity at all concentrations. BNQD had moderate antibacterial activity against all tested microorganisms. Biofilm inhibition percentage of BNQD was determined as 82.31 % at 500 mg/L. Cell viability assay demonstrated that the BNQD showed strong cell viability inhibition 99.9 % at the concentration of 1000 mg/L. The porosity increased from 56.83 ± 1.17%–61.83 ± 1.17 % while BNQD concentration increased from 0 to 2.00 wt%. Moreover, the hydrophilicity of BNQD nanocomposite membranes also increased from 75.42 ± 0.56° to 65.34 ± 0.25°. The mean pore radius is far slightly changed from 16.47 ± 0.35 nm to 19.16 ± 0.22 nm. The water flux increased from 133.5 ± 9.5 L/m2/h (for pristine membrane) to 388.6 ± 18.8 L/m2/h (for PES/BNQD 2.00 wt% membrane). BSA flux increased from 38.8 ± 0.9 L/m2/h to 63.2 ± 2.7 L/m2/h up to 1.00 wt% amount of BNQD nanoparticles.