Azinobis (3-ethylbenzothiazoline-6-sulphonic Acid) Diammonium Salt Research Articles

Phytochemical Screening, Polyphenol and Flavonoid Contents, and Antioxidant and Antimicrobial Activities of Opilia amentacea Roxb. (Opiliaceae) Extracts

Dermatoses are essentially caused by infection or free radical aggression, immunoallergic disorders, or can be secondary to general diseases. Management of dermatoses by modern medicine is complex and costly, and the development of alternative treatments is urgent. Opilia amentacea Roxb. is a woody climber plant traditionally used in Burkina Faso for treatment of bad skin diseases. This study was carried out to evaluate the antimicrobial and antioxidant activities of extracts of O. amentacea and to characterize potent fractions. The antimicrobial activity was determined using the disc diffusion and microdilution methods, while antioxidant activity was assessed using the 2,2′-diphenyl-1-picrylhydrazyl radical (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) and ferric reducing antioxidant power (FRAP) assays. The content of the plant extracts in polyphenols and flavonoids was also studied. The results revealed several secondary metabolites in the leaves, stems and root bark extracts of the plant, including sterols, triterpenes, and flavonoids and tannins, and a generally high total polyphenol and total flavonoid content. Dichloromethane fractions of leaves (FDFe) and stem barks (FDET) exhibited the best antioxidant activity and were the most active on Gram-positive bacilli. Hexane leaves (FHFe) and hexane root bark (FHER) fractions exhibited the best antifungal activity against Candida tropicalis. High correlation (R2 = 0.932) was found between the total flavonoid content of extracts and ferric-reducing antioxidant power. In view of these results, the present study describes O. amentacea as a potential source of antibacterial, antifungal and antioxidant agents and justifies the traditional uses of the plant as an anti-dermatosis plant.

Improving grindability and bioaccessibility of chicken bone by in situ steam explosion

SummaryThe impacts of in situ steam explosion (ISE) on the particle size, protein solubility and digestibility, calcium release and structural characteristics of chicken bone powder were analysed. ISE significantly reduced the average particle size from 142.62 to 84.47–105.10 μm, while maintained the proximate compositions. The Fourier transforms infrared spectra and X‐ray diffraction further illustrated that there were no marked differences in the functional groups between native and ISE bone powders. Moreover, soluble protein content in chicken bone powder was remarkably enhanced by the ISE from 3.28 to 3.73 mg g−1. ISE powder (at 121 °C for 90 min) had higher protein digestibility (48.63%) than that of native (30.82%). Finally, ISE powder showed a higher calcium release and 2,2′‐azino‐bis (3‐ethylbenzothiazoline‐6‐sulphonic acid) diammonium salt (ABTS) radical scavenging activity of digestive juice. The results proposed the feasibility of using ISE as an effective strategy to improve the nutritional quality of chicken bone.

Functional Coating from Amyloid Superwetting Films.

Tailoring the hydrophilicity of solid surfaces with a strong affinity to water has been extensively explored in the last 20 years, but studies have been limited to the single function of wettability. Here, the multifunctional properties of tailored surface films are extended from exhibiting superwettability to facilitating biological activities. It is shown that amyloid fibrils can be universally coated onto various substrates, such as fabrics (non-woven organic masks), metal meshes, polyethersulfone (PES), glass, and more, endowing the resulting surfaces with excellent performance in oil/water mixture and emulsion separation, antifouling, and antifogging. Moreover, the biocompatible crosslinked amyloid fibril coatings can serve as a platform for biocatalytic activities by immobilizing enzymes, as shown in the 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) oxidation and Reactive Black 5 (RB5)degradation by laccase from Trametes versicolor. The study provides a universal approach to modifying surface morphology and chemical properties via fibrous protein templates, opening the way to unexplored bio-based applications and functionalities.

Antimicrobial and Antioxidant Secondary Metabolites from Trifolium baccarinii Chiov. (Fabaceae) and Their Mechanisms of Antibacterial Action.

The treatment of infectious diseases with antimicrobial agents continues to present problems in modern-day medicine with many studies showing significant increase in the incidence of bacterial resistance to several antibiotics. The screening of antimicrobial activity of plant extracts and natural products has shown that medicinal plants are made up of a potential source of new anti-infective agents. The aim of this study was to evaluate the antimicrobial and antioxidant activities of extracts and compounds from the whole plant Trifolium baccarinii Chiov. and to determine their modes of antibacterial action. The plant extracts were prepared by maceration in organic solvents. The antimicrobial activities were evaluated using the broth microdilution method. The antioxidant activity was evaluated using the 2,2′-diphenyl-1-picrylhydrazyl radical (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) assays. The mechanisms of antibacterial action were determined by lysis, salt tolerance assays, and antioxidant enzyme activities. The cytotoxic effect on the erythrocytes was determined by a spectrophotometric method. Biochanin A, formononetin, luteolin, luteolin-4′-O-β-D-glucopyranoside, 4,7,2′-trihydroxy-4′-methoxyisoflavanol, sissotrin, 1-methyl-β-D-glucopyranoside, ononin, D-mannitol, and 3-O-β-D-glucuronopyranosylsoyasapogenol B were isolated from Trifolium baccarinii. The MeOH, EtOAc, and n-BuOH extracts as well as biochanin A, formononetin, luteolin, luteolin-4′-O-β-D-glucopyranoside, 4,7,2′-trihydroxy-4′-methoxyisoflavanol, and sissotrin from Trifolium baccarinii displayed the highest antimicrobial and antioxidant activities. The MeOH extract and 4,7,2′-trihydroxy-4′-methoxyisoflavanol exhibited antibacterial activity through the bacteriolytic effect and reduction of the antioxidant defenses in the bacterial cells. The present study portrays Trifolium baccarinii as a potential natural source of antibacterial, antifungal, and antioxidant agents.

Multifunctional Tyrosinase Inhibitor Peptides with Copper Chelating, UV-Absorption and Antioxidant Activities: Kinetic and Docking Studies.

Nature-derived tyrosinase inhibitors are of great industrial interest. Three monophenolase inhibitor peptides (MIPs) and three diphenolase inhibitor peptides (DIPs) from a previous study were investigated for their in vitro tyrosinase inhibitory effects, mode of inhibition, copper-chelating activity, sun protection factor (SPF) and antioxidant activities. DIP1 was found to be the most potent tyrosinase inhibitor (IC50 = 3.04 ± 0.39 mM), which could be due to the binding interactions between its aromatic amino acid residues (Y2 and D7) with tyrosinase hotspots (H85, V248, H258, H263, F264, R268, V283 and E322) and its ability to chelate copper ion within the substrate-binding pocket. The conjugated planar rings of tyrosine and tryptophan may interact with histidine within the active site to provide stability upon enzyme-peptide binding. This postulation was later confirmed as the Lineweaver–Burk analysis had identified DIP1 as a competitive inhibitor and DIP1 also showed 36.27 ± 1.17% of copper chelating activity. In addition, DIP1 provided the highest SPF value (11.9 ± 0.04) as well as ferric reducing antioxidant power (FRAP) (5.09 ± 0.13 mM FeSO4), 2,2′–azinobis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) (11.34 ± 0.90%) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) (29.14 ± 1.36%) free radical scavenging activities compared to other peptides. These results demonstrated that DIP1 could be a multifunctional anti-tyrosinase agent with pharmaceutical and cosmeceutical applications.

Poly-γ-Glutamic Acid/Chitosan Hydrogel Nanoparticles Entrapping Glucose Oxidase and Magnetic Nanoparticles for Glucose Biosensing.

We have developed hydrogel nanoparticles made of poly-γ-glutamic acid (PGA) and chitosan, which entraps both glucose oxidase (GOx) and magnetic nanoparticles (MNPs) within the hydrogel matrix. The preparation of poly-γ-glutamic acid/chitosan hydrogel nanoparticles (PGA/CS NPs) entrapping GOx and MNPs begins with the mixing of GOx and MNPs with PGA solution followed by their dropwise addition into chitosan solution to induce rapid ionic gelation. The glucose sensing relies on the generation of H2O2 through the entrapped GOx-mediated catalysis in the presence of glucose, which consequently activates the peroxidase-like activity of MNPs to convert an employed chromogenic substrate, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS), into a green colored product. Using this strategy, the target glucose was successfully detected over a wide linear range, from 5 to 100 μM with a lower detection limit of 3 μM, which is sufficient to diagnose high level of glucose (hyperglycemia) in human blood. The hydrogel nanoparticle-based glucose biosensor also showed high stability with magnetic reusability. Since any oxidative enzymes could be incorporated within the PGA/CS NPs, we expect that the hydrogelbased biosensor would be highly beneficial for the detection of various other clinically important target molecules.

Multiple Tolerance and Dye Decolorization Ability of a Novel Laccase Identified from Staphylococcus Haemolyticus.

Laccases are multicopper oxidases with important industrial value. In the study, a novel laccase gene (mco) in a Staphylococcus haemolyticus isolate is identified and heterologously expressed in Escherichia coli. Mco shares less than 40% of amino acid sequence identities with the other characterized laccases, exhibiting the maximal activity at pH 4.0 and 60°C with 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) as a substrate. Additionally, the Mco is tolerant to a wide range of pH, heavy metal ions and many organic solvents, and it has a high decolorization capability toward textile dyes in the absence of redox mediators. The characteristics of the Mco make this laccase potentially useful for industrial applications such as textile finishing. Based on BLASTN results, mco is found to be widely distributed in both the bacterial genome and bacterial plasmids. Its potential role in oxidative defense ability of staphylococci may contribute to the bacterial colonization and survival.

Effects of Bromelain and Trypsin Hydrolysis on the Phytochemical Content, Antioxidant Activity, and Antibacterial Activity of Roasted Butterfly Pea Seeds

Butterfly pea (Clitoria ternatea L.) is a traditional medicinal and edible herb, whose health-promoting benefits have been attributed to its phenolic constituents. In this study, the effects of enzymatic hydrolysis on total phenolic content (TPC) and total flavonoid content (TFC), antioxidant (2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP)) and antibacterial activities of raw and roasted (200 °C, 10–20 min) butterfly pea seeds were investigated. Roasting reduced the yield of seed aqueous extracts, but it increased the TPC and FRAP values, hence the reducing ability, of the extracts. Bromelain hydrolysis enhanced the TPC and TFC of the roasted seeds up to 2- and 18-fold higher, respectively. Trypsin hydrolysis drastically increased the TPC, but not TFC, of roasted seeds; trypsin-hydrolyzed, 20 min roasted sample had the highest TPC (54.07 μg gallic acid equivalent (GAE)/mg) among all samples. Bromelain hydrolysis significantly improved the antioxidant activity of the roasted seed samples, where the antioxidant activity of bromelain-hydrolyzed, 20 min roasted sample was about 50% greater than the non-hydrolyzed 20 min roasted sample. Trypsin hydrolysis raised the FRAP values of the 20 min roasted sample to 70.28 mg Fe(II) equivalent/g, the highest among all samples. Nevertheless, trypsin only weakly elevated the ABTS scavenging activity of the roasted samples, showing no enhancement of the DPPH scavenging activity. On the other hand, only bromelain hydrolysates of raw and 10 min roasted seeds were active against Staphylococcus aureus. Taken together, bromelain hydrolysis can be used to enhance the extractable phytochemical contents and antioxidant activity of roasted butterfly pea seeds.

Anti-Wrinkling and Anti-Melanogenic Effect of Pradosia mutisii Methanol Extract.

Ultraviolet (UV) exposure causes skin photoaging leading to skin wrinkling and sagging via production of reactive oxygen species (ROS). For this reason, protection from photoaging is an important feature in cosmeceutical and dermatological products. Natural product-derived biomaterials are highly desired as future possible ingredients, because these biomaterials are often safe and effective. In this study, we aimed to characterize the skin protective activity of Pradosia mutisii, traditionally used to treat sunburn and erythema. We determined the free radical scavenging, anti-melanogenic, and moisturizing effects of a methanol extract of Pradosia mutisii (Pm-ME) in keratinocytes (HaCaT cells), melanocytes (B16F10 cells), and fibroblasts (human dermal fibroblasts (HDFs)) at non-cytotoxic concentrations. Pradosia mutisii methanol extract contains coumaric acid as a major component, and the extract exhibited protective activity against UVB- and H2O2-induced cytotoxicity. This extract also suppressed the expression of metalloproteinases (MMPs) and cyclooxygenase (COX)-2 in HaCaT cells. A reduction of Sirt-1 expression under UVB- and H2O2-treated conditions was recovered in HaCaT cells by Pm-ME. This extract displayed significant free radical scavenging activity according to the 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) assay. The Pm-ME also upregulated the expression levels of hyaluronic acid synthase (HAS) and transglutaminase-1 (TGM-1) in HaCaT cells, indicating a putative moisturizing activity. Interestingly, the expression of collagen type 1 (Col1A1) gene and its promoter activity, as assessed by a reporter gene assay, were found to be increased in HDF and HEK293 cells. Similarly, Pm-ME helped recover collagen levels after UVB and H2O2 treatment in HDFs as well as decreased the synthesis and secretion of melanin from B16F10 melanoma cells, which may indicate a beneficial whitening cosmetic value. The p38 inhibitor SB203580 and the JNK inhibitor SP600125 suppressed MMP-9 and COX-2 expression in H2O2-treated HaCaT cells. Similarly, the ERK inhibitor U0126 inhibited HAS-2 in Pm-ME/H2O2-treated HaCaT cells. These findings suggested that inhibition of JNK and p38 and activation of ERK could be targeted by Pm-ME. Therefore, Pm-ME may exert anti-photoaging and anti-melanogenic properties via the regulation of mitogen-activated protein kinase, which could be beneficial in the cosmeceutical industry.

Spectrum-Effect Relationships between High-Performance Liquid Chromatography (HPLC) Fingerprints and the Antioxidant and Anti-Inflammatory Activities of Collagen Peptides.

A total of 13 batches of collagen peptide samples were extracted, isolated, and purified from chicken sternal cartilage under various process parameters. The fingerprint profiles of 13 batches of collagen peptides were established by high-performance liquid chromatography (HPLC). In addition, the amino acid profiles and molecular weight distributions of collagen peptides were investigated. The in vitro antioxidant activities of the peptide samples were measured using the 2,2′-Azinobis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) assay, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, the ferric-reducing antioxidant power (FRAP) assay and an assay of the oxidative damage induced by hydrogen peroxide (H2O2) in the degenerative cartilage cells from the knee joint of rat C518 (C518 cell line). The anti-inflammatory activities of the peptide samples were assessed by measuring the inflammatory responses induced by lipopolysaccharides (LPS) in C518 cells. Subsequently, the spectrum-effect relationships between HPLC fingerprints and the antioxidant and anti-inflammatory activities of collagen peptides were investigated using grey relational analysis (GRA). Fifteen common peaks were obtained from the HPLC fingerprints of collagen peptides. Each collagen peptide sample had a characteristic set of amino acid types and contents. All of the hydrolysates of the collagen peptides were primarily composed of fractions II (500–1000 Da) and III (1000–3000 Da). Collagen peptides exhibited good scavenging activity on ABTS radical, DPPH radical, and ferric-reducing antioxidant power. Collagen peptides were also effective against H2O2-induced cellular oxidative damage in C518 cells. The antioxidant activity of collagen peptides was due to the low molecular weight and the presence of antioxidant and hydrophobic amino acid residues within its sequence. Collagen peptides significantly inhibited the secretion of inflammatory cytokines IL-1β, TNF-α, and PGE2 in C518 cells. The anti-inflammatory activity of collagen peptides may include increased synthesis of the key components of extracellular matrix (ECM) and inhibited apoptosis of chondrocytes. The GRA results showed that peaks 2, 3, and 8 were the main components contributing to the antioxidant activity of the collagen peptides, whereas peaks 11 and 14 were the main components contributing to the anti-inflammatory activity of the collagen peptides. The components of peaks 8 and 14 were identified as GPRGPPGPVGP and VAIQAVLSLYASGR by UPLC-MS/MS. Those identified collagen peptides offer a potential therapeutic strategy for the treatment of osteoarthritis (OA) due to their antioxidative stress and due to them disturbing the catabolism and anabolism processes in arthrodial cartilage.

Fractionation and identification of novel antioxidant peptides from fermented fish (pekasam)

The goals of this study were to determine antioxidant activities of water soluble fractions of a Loma fermented fish extract and identify the novel antioxidant peptides by HPLC connected to the tandem mass spectrometry (LC/MS/MS). The antioxidant activities of Loma fermented fish (LFF) were measured by evaluating 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activities. Antioxidant peptides from LFF were separated using ultrafiltration, size exclusion chromatography and HPLC. Purified fraction (FIII 3), which exhibited the strongest ABTS radical scavenging activity, with the IC50 value of 0.636 mg/ml, had higher antioxidant activity than the LFF sample without fractionation (with IC50 of 2.24 mg/ml). Two novel peptides were identified as Ala-Ile-Pro-Pro-His-Pro-Tyr-Pro (AIPPHPYP) and Ile-Ala-Glu-Val-Phe-Leu-Ile-Tre-Asp-Pro-Lys (IAEVFLITDPK). The IAEVFLITDPK peptide demonstrated higher antioxidant activity than the AIPPHPYP. The presence of hydrophobic amino acids (Ile, Ala and Pro), and basic amino acids, (Lys) in the peptide sequences is believed to contribute to the high antioxidant activity of the LFF. Therefore, these peptides may have the potential as a natural functional ingredient in food and pharmaceutical industries.

Composition and biological activities of Libyan Salvia fruticosa Mill. and S. lanigera Poir. extracts

This study was aimed to analyze the chemical composition and biological activities of extracts of Salvia fruticosa and S. lanigera originated from Libya. Dichloromethane, ethyl acetate, methanol, ethanol and water extracts obtained from wild growing plants were analyzed for the composition using HPLC-DAD, which revealed presence of phenolic acids and flavonoids, mainly in alcoholic and water extracts. Total phenolic and flavonoid contents, as well as anti-oxidant activity using 2.2-diphenyl-1-picrylhydrazyl (DPPH), 2.2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid diammonium salt (ABTS), ferric reducing anti-oxidant potential (FRAP) and β-carotene bleaching (β-CB) assays were determined spectrophotometrically. Extracts of S. fruticosa exhibited stronger activity in all applied assays, especially ethanol extract in DPPH assay (IC50, 29.55 μg/mL) and in β-CB assay (85.11%). The ethanol and water extracts were selected for further investigation, because of their wide usage in phytotherapy. The extracts were screened for the antimicrobial activity against 11 bacteria (six Gram-negative and five Gram-positive) and seven fungi using microdillution method. Ethanol extracts showed stronger activity than water extracts, particularly against Gram-positive bacteria. Trichophyton mentagrophytes was the most sensitive to the water extract of S. lanigera (MIC, minimal inhibitory concentration and MFC, minimal fungicidal concentration, 8 mg/mL). Cytotoxic activity on human carcinoma cell line HCT-116 was determined by 3-(4.5-dimethylthiazol-2-yl)-2.5-diphenyl tetrazolium bromide (MTT) cell viability assay, where only ethanol extract of S. fruticosa demonstrated certain activity (IC50, 375.96 μg/mL). The testing of anti-neurodegenerative activities of extracts showed better tyrosinase inhibiting effect (55.26–74.66%) than standard kojic acid (33.93–51.81%), while the extracts were less effective against acetylcholinesterase compared with standard galanthamine. According to the obtained results, S. fruticosa and S. lanigera originated from Libya have proved to be the promising source of natural compounds possessing a range of biological activities.

IN VITRO FREE RADICAL SCAVENGING ACTIVITY AND IN VIVO ANTICATARACT POTENTIAL OF HEMIDESMUS INDICUS ROOTS IN STREPTOZOTOCIN INDUCED DIABETIC RATS

Objective: Hemidesmus indicus R. Br. (HI) (Indian sarsaparilla) is traditionally used in Indian medicine for human therapy. The present study was aimed to evaluate the antioxidant activity of HI root extracts, and its effects on delaying (or) management of cataract progression in streptozoticin (STZ) induced diabetic rats.Methods: The plant roots were extracted in different solvents, estimated total phenolic content, total flavonoid content and conducted free radical scavenging potential through 1,1-Diphenyl-2-picrylhydrazyl (DPPH), 2,2 azinobis (3-ethyl benzothiazoline-6-sulphonic acid diammonium salt (ABTS) NO, OH and reducing power assays. Further, the protective effect was evaluated in STZ induced diabetic rats through administered of ethyl acetate extract of HI (200 and 400 mg/kg body weight) orally for 8 weeks to study its effect on oxidative stress and diabetic cataract progression.Results: In primary results demonstrated that the ethyl acetate extract has been showed considerable free radical scavenging activity and significantly gain body weight, gradual decreasing blood glucose levels and delay cataract progression has been observed in HI treated rats. Furthermore, we observed significantly decreased oxidative stress markers, and restoration of the antioxidant system in HI treated rats. Lens sections from experimental animal again evidenced to conform the ameliorative effect of HI on diabetic cataract.Conclusion: This obtained result’s confirmed that the protective effect of HI is attributed to the antioxidant activities of plant roots and its active principles.

HPLC-DAD-ESI-MS/MS analysis of fruits from Firmiana simplex (L.) and evaluation of their antioxidant and antigenotoxic properties.

The secondary metabolites of the fruits of Firmiana simplex (L.) were analysed by LC-DAD-ESI-MS/MS; furthermore, we evaluated their antioxidant and antigenotoxic properties. The antioxidant activity was investigated using the 2,2'-diphenyl-1-picrylhydrazyl radical (DPPH), the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) and the ferric reducing antioxidant power (FRAP) assays. The antigenotoxic potential was determined via the comet assay. The ethyl acetate fraction (EtOAc) was analysed by LC-DAD-ESI-MS/MS: phenolic acids and flavonoids were the main polyphenols of the fruits. The EtOAc fraction yielded the highest content of polyphenols with 314.61mg GAE/g extract, followed by 297.51, 153.75, 101.47, 97.19 for dichloromethane, butanol, methanol and water extracts, respectively. As expected, a strong correlation exists between the antioxidant activity of the investigated extracts and their total phenolic content. In the DPPH assay, the IC50 value of the most active EtOAc fraction was 6.79μg/ml, relative to 2.92μg/ml of the standard ascorbic acid. ABTS and FRAP assays supported the results of DPPH assay. Moreover, using the comet assay, we could show that the phenol-rich EtOAc extract exhibits an antigenotoxic potential in human liver cancer cells (Hep-G2) treated with hydrogen peroxide (H2 O2 ) as a genotoxic agent. The fruits of Firmiana simplex may be a good natural source of antioxidant and antigenotoxic agents.

Effects of simulated gastrointestinal digestion on the physicochemical properties, erythrocyte haemolysis inhibitory ability and chemical antioxidant activity of mulberry leaf protein and its hydrolysates

SummaryProteins and peptides must be degraded and modified in the gastrointestinal (GI) tract prior to absorption; this process changes their physicochemical and biological properties. Mulberry leaf protein (MP) and its hydrolysates (HMP) have favourable antioxidant activities. To investigate, in vitro and separately, the effects of GI digestion and intestinal digestion on the stability of MP and HMP, we monitored the changes in secondary structures, amino acids, molecular weights and antioxidant activities. We found that MP was more hydrolysed by pepsin than by pancreatin, unlike HMP. The final digests of MP and HMP were mainly composed of polypeptides (0.5–6.5 kDa) and oligopeptides (<0.5 kDa), respectively. The GI digestion influenced MP and HMP differently; GI digestion increased the antioxidant efficiency of MP and decreased that of HMP. For the intestinal digests, the antioxidant activities of MP and HMP also differed. The 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) and 2,2′‐azinobis (3‐ethylbenzothiazoline‐6‐sulphonic acid) diammonium salt (ABTS) radical quenching abilities of MP and HMP at 1 mg mL−1 were comparable to or exceeded that of L‐glutathione (GSH) and 6‐hydroxy‐2,5,7,8‐tetramethychroman‐2‐carboxylic acid (trolox). Meanwhile, the erythrocyte haemolysis rates of MP, HMP and their GI products at 0.05–1.0 mg mL−1 were significantly lower than that of the 2,2′‐azobis (isobutyramidine) dihydrochloride (AAPH) control. Both MP and HMP can be used as natural antioxidants and may promote digestive health.

Effects of gamma irradiation and comparison of different extraction methods on sesquiterpene lactone yields from the medicinal plant Thapsia garganica L. (Apiaceae)

Ethnopharmacological relevanceThapsia garganica L. roots are used in Algerian traditional medicine for a number of ailments. It is used in a poultice as an antitussive treatment of acute bronchitis and pneumonia, in preparations with milk or oil taken orally to treat common lung diseases, and with the direct application of root sections for the soothing of dental pains. Aim of the studyThe objective of this study was to evaluate the combined effect of microwave assisted extraction and gamma irradiation on sesquiterpene lactones in T. garganica extracts Materials and methodsTo evaluate the combined effect of microwave assisted extraction and gamma irradiation on the highly bioactive compounds found in extracts of Algerian T. garganica, samples from different locations in Algeria were prepared by extraction from dried leaf and root samples of dried plant material, using different extraction methods Quantification of the compounds of interest was done using an HPLC. The antioxidant activity extracts was determined using the two free radical scavenging assays: the 2,2-diphenyl-picryl-hydrazyl (DPPH) and the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS). ResultsIt was found that location and extraction method had significant impact on the phytochemical composition of extracts. Gamma irradiation was found to have no effect on the phytochemical composition of the plant extracts or on their antioxidant properties. ConclusionThe study has shown that microwave assisted extraction is an effective method for investigating chemical compounds in T. garganica and the results support the notion that gamma irradiation for sterilisation do not alter the chemical composition.The authors wish to clarify that we cannot recommend the usage of any parts of T. garganica, in any form, for any remedy due to its very high toxicity.

Influence of ripening stage on bioactive compounds and antioxidant activity in nine fig (Ficus carica L.) varieties grown in Extremadura, Spain

The aim of this study was to characterise nine commercial fig (Ficus carica L.) varieties differing in colour (dark-purple, brown, green, and yellow-green) at three different ripening stages in regards to the health-promoting compounds of their fruits and to identify and quantify the bioactive compounds as well as total antioxidant activity (TAA) in the skin and flesh of each variety. Significant differences (p<0.05) were found between varieties and ripening stages. Dark-coloured varieties showed the highest levels of total phenolic compounds (from 26.7 to 169.5mg gallic acid equivalents/100g), quercetin-3-O-rutinoside (between 4.6 and 11.9mg/100g), and anthocyanins, specially cyanidin-3-O-rutinoside (from 3.03 to 97.4mg/100g), while brown-, green-, and yellow-green-coloured varieties contained the highest levels of chlorogenic acid (between 0.7 and 2.1mg/100g), total Vitamin C (from 0.8 to 9.0mg/100g), and (+)-catechin as proanthocyanin cleavage products (from 3.1 to 17.3mg/100g). Levels of TAA were measured by 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) total radical scavenging capacity both in hydrophilic (H-TAA) and lipophilic (L-TAA) fractions. The darker varieties exhibited higher H-TAA values, ranging from 16.3 to 177.4mmol Trolox equivalents/100g, than the lighter ones. In the case of L-TAA, its concentration also depended directly on the genotype and less on the ripening stage. We found higher concentrations of bioactive compounds and a higher antioxidant capacity in the skin compared to the flesh; moreover, their content increased during the ripening process, reaching the maximum level of phenolic compounds at stage three, although these changes were deeper in the dark-coloured varieties and in the brown-coloured variety ‘San Antonio’ Based on our results, it is advisable to consume unpeeled, fully ripe, dark figs in order to optimally benefit from the health-promoting properties.

Antioxidant Synergetic Effect Between the Peptides Derived from the Egg White Pentapeptide Trp-Asn-Trp-Ala-Asp

When foods are intaken together, the antioxidant activity of mixtures may present synergistic, additive, or antagonistic interactions. The aim of this study was to investigate the oxygen radical absorbance capacity (ORAC) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonicacid) diammonium salt (ABTS) radical scavenging activity of (Trp-Asn-Trp-Ala-Asp) WNWAD, a pentapeptide derived from egg white ovomucin pepsin hydrolysates, and its fragments as well as the effect of WNWAD on cellular antioxidant enzymes activities. The ORAC assays demonstrated that combined group (WN + WAD) significantly improved the antioxidant activities, while combined group (WNW + AD) decreased the antioxidant activities. The ABTS assays showed peptide fragments (WNW, WN, WAD) and its mixture (WNW + AD, WN + WAD) have lower EC50 than antioxidant peptide WNWAD in ABTS assay. Various combinations of peptide were found to have synergistic interaction, and synergistic interaction exhibited certain dose-dependently interactions. At cellular level, the activities of SOD, GSH-Px, CAT were higher while the level of MDA, LDH release were lower in the peroxide + peptide-treated group when compared to the peroxide exposed group. Results in this study imply the importance of exploiting synergism interactions in the development of new functional food.

Phytochemical profiles and antioxidant activities of Chinese dark teas obtained by different processing technologies

Dark teas are rich in secondary metabolites, such as phenolics and flavonoids, which have been suggested to be associated with their health benefits. In this study, the concentrations of tea polyphenols, tea pigments, catechins, flavonoids, alkaloid, and volatile components in 44 dark tea samples, including Pu-erh, Fuzhuan and Liubao teas, were systematically examined. Among the samples tested, Pu-erh tea contained the highest total flavonoid content (5.24±0.05%), followed by Liubao (4.45±0.61%) and Fuzhuan teas (3.33±0.23%). The tea polyphenols levels in the dark teas were approximately 10%, and no statistically significant differences (p>0.05) were found among the different types. Hexadecanoic acid was the most abundant aroma component in the dark teas, accounting for 15–20% of the total volatile oils. Moreover, the antioxidant activities of these dark teas were analyzed using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) assay, ferric reducing antioxidant power (FRAP) assay, and cellular antioxidant activity (CAA) assay (HepG2 cells). The fat metabolism modulation activities (FMMA) of the dark teas were tested using a high-throughput screening method (SMMC-7221 cells). The results indicated that the different dark teas had diverse antioxidant activities, and the variation in the activities was significant. Correlation analysis showed that there was a significant positive correlation between the levels of EGCG and antioxidant activities measured using the ABTS (r=0.916) and FRAP (r=0.853) assays, and the levels of total flavonoids and theabrownins correlated well with the values determined using the CAA (r=0.845 and 0.865, respectively) assay.

Antioxidant and Angiotensin I Converting Enzyme (ACE) Inhibitory Properties of GL-9 Peptide

The aim of this study was to examine antioxidant and inhibitory activity of Gly-Ala-Ser-Arg-His-Trp-Tyr-Phe-Leu peptide named GL-9 peptide. The synthetic GL-9 peptide was purified by C8 reveres phase HPLC (RP-HPLC). The antioxidant activity of the GL-9 peptide was investigated based on its scavenging capacity1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, 2,2′-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS), superoxide ( ), hydroxyl (OH•−) and lipid peroxidation inhibition. The ACE inhibitory activity and kinetic parameters of the peptide were determined using FAPPG as substrate. GL-9 peptide/ACE complex interaction, position, type and energy was also investigated by using molecular docking. GL-9 peptide displays DPPH (IC50 = 6.5 µg/mL), ABTS•+ (IC50 = 7.2 µg/mL), superoxide (IC50 = 122 µg/mL) and hydroxyl (IC50 = 60.0 µg/mL) radical scavengers. GL-9 peptide showed an IC50 value of 47.8 µg/mL which inhibited ACE activity. The results indicated that the GL-9 peptide has antioxidant and ACE inhibitory capacity. Practical Applications Synthetic GL-9 peptide antioxidant and anti-hypertensive activity were investigated using in vitro assays. Results indicated that this peptide possesses a high potent antioxidant activity as well as ACE-inhibitory activity, demonstrate its potential application as an ingredient in wholesome foodstuffs.