Chelating Activity Research Articles

Effects of Soaking and Germination Treatments on the Nutritional, Anti-Nutritional, and Bioactive Characteristics of Adzuki Beans (Vigna angularis L.) and Lima Beans (Phaseolus lunatus L.).

Lima beans (Phaseolus lunatus) and adzuki beans (Vigna angularis) are some of the most nutritious underutilized pulses that are significant in being used as basic ingredients for the preparation of various food products. The present study aimed to determine the impact of soaking and germination on nutritional and bioactive components, in vitro protein digestibility, reducing power, metal chelating capacity, antioxidant activity, and anti-nutritional components of lima and adzuki beans. The findings showed that during the germination treatment, the in vitro protein digestibility of lima and adzuki beans increased by 14.75 and 10.98%, respectively. There was an increase in the antioxidant activity of lima beans by 33.48% and adzuki beans by 71.14% after 72 h of germination, respectively. The reducing power assay of lima and adzuki beans indicated an increase of 49.52 and 36.42%, respectively, during germination. Similarly, the flavonoid and metal chelating activity increased in lima and adzuki beans after 72 h of germination. In contrast, the anti-nutrients, such as phytic acid, tannin content, and trypsin inhibitor activity, decreased significantly p < 0.05 after 72 h of germination. These results are encouraging and allow for utilizing the flour obtained from the germinated beans in functional bakery products, which can contribute to eradicating protein deficiency among some population groups. At the same time, promoting soaking and germination of the beans as a way to enhance the nutritional quality and reduce anti-nutrients can contribute to the interest in these underutilized pulses. They could be seen as an additional tool to improve food security.

Phlomis crinita Cav. From Algeria: A source of bioactive compounds possessing antioxidant and wound healing activities

Ethnopharmacological relevancePhlomis crinita Cav. (Lamiaceae), locally known as “El Khayata” or “Kayat El Adjarah”, is traditionally used in Algeria for its wound-healing properties. Aim of the studyInvestigate, for the first time, the phytochemical profile, safety, antioxidant and wound-healing activities of the flowering tops methanolic extract of P. crinita (PCME) collected from Bouira Province in the North of Algeria. Materials and methodsPreliminary phytochemical assays were carried out on PCME to quantify the main classes of bioactive compounds, such as total phenols, flavonoids, and tannins. An in-depth LC-DAD-ESI-MS analysis was carried out to elucidate the phytochemical profile of this plant species. Antioxidant activity was investigated by several colorimetric and fluorimetric assays (DPPH, TEAC, FRAP, ORAC, β-carotene bleaching and ferrozine assay). The acute oral toxicity of PCME (2000 mg/kg b.w.) was tested in vivo on Swiss albino mice, whereas the acute dermal toxicity and wound-healing properties of the PCME ointment (1–5% PCMO) were tested in vivo on Wistar albino rats. Biochemical and histological analyses were carried out on biological samples. ResultsThe phytochemical screening highlighted a high content of phenolic compounds (175.49 ± 0.8 mg of gallic acid equivalents/g of dry extract), mainly flavonoids (82.28 ± 0.44 mg of quercetin equivalents/g of dry extract). Fifty-seven compounds were identified by LC-DAD-ESI-MS analysis, belonging mainly to the class of flavones (32.27%), with luteolin 7-(6″-acetylglucoside) as the most abundant compound and phenolic acids (32.54%), with salvianolic acid C as the most abundant compound. A conspicuous presence of phenylethanoids (15.26%) was also found, of which the major constituent is forsythoside B. PCME showed a strong antioxidant activity with half-inhibitory activity (IC50) ranging from 1.88 to 37.88 μg/mL and a moderate iron chelating activity (IC50 327.44 μg/mL). PCME appears to be safe with Lethal Dose 50 (LD50) ≥ 2000 mg/kg b.w. No mortality or toxicity signs, including any statistically significant changes in body weight gain and relative organs’ weight with respect to the control group, were recorded. A significant (p < 0.001) wound contraction was observed in the 5% PCMO-treated group with respect to the untreated and petroleum jelly groups between 8 and 20 days, whereas no statistically significant results were observed at the two lower doses (1 and 2% PCMO). In addition, the 5% PCMO-treated group showed a statistically significant (p < 0.05) wound healing activity with respect to the reference drug-treated group, showing, at the end of the study, the highest wound contraction percentage (88.00 ± 0.16%). ConclusionPCME was safe and showed strong antioxidant and wound-healing properties, suggesting new interesting pharmaceutical applications for P. crinita based on its traditional use.

Acid-hydrolyzed phenolic extract of parsley (Petroselinum crispum L.) leaves inhibits lipid oxidation in soybean oil-in-water emulsions

The antioxidant activity of the natural phenolic extracts is limited in particular food systems due to the existence of phenolic compounds in glycoside form. Acid hydrolysis post-treatment could be a tool to convert the glycosidic polyphenols in the extracts to aglycones. Therefore, this research investigated the effects of an acid hydrolysis post-treatment on the composition and antioxidant activity of parsley extracts obtained by an ultrasound-assisted extraction method to delay lipid oxidation in a real food system (i.e., soybean oil-in-water emulsion). Acid hydrolysis conditions were varied to maximize total phenolic content (TPC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. When extracts were exposed to 0.6 M HCl for 2 h at 80 ℃, TPC was 716.92 ± 24.43 µmol gallic acid equivalent (GAE)/L, and DPPH radical scavenging activity was 66.89 ± 1.63 %. Not only did acid hydrolysis increase the concentrations of individual polyphenols, but it also resulted in the release of new phenolics such as myricetin and gallic acid. The extract's metal chelating and ferric-reducing activity increased significantly after acid hydrolysis. In soybean oil-in-water emulsion containing a TPC of 400 µmol GAE/L, the acid-hydrolyzed extract had an 11-day lag phase for headspace hexanal compared to the 6-day lag phase of unhydrolyzed extract. The findings indicated that the conversion of glycosidic polyphenols to aglycones in phenolic extracts can help extend the shelf-life of emulsion-based foods.

Bioactive Compounds of Rosa canina L. and Their Effect on Tumor Necrosis Factor-α and Interleukin-1β Activity in Diabetes-Induced Rats

The ethnopharmacological significance of Rosa canina, or dog rose, transcends diverse cultures, with traditional applications in treating various diseases. This study investigates the potential pharmacological application of Rosa canina for diabetes treatment, aiming to assess its antidiabetic properties through in vitro, in vivo, and in silico analyses targeting pro-cytokines. Biochemical profiling utilizing HPLC, and phenolic content analyses were conducted to reveal the antioxidant properties of Rosa canina. In diabetic rats, root extracts influenced the expression of TNF-α and IL-1β, with an exploration of DNA-binding and protective activities. DPPH scavenging and iron chelating activities were measured, identifying significant IC50 values. The chromatographic analysis identified various compounds, with Kaempferol 3-O-glucoside and Rutin exhibiting high inhibitory activity against TNF-alpha. In silico analyses highlighted inhibitory activities by molecular docking against TNF-α and IL-1β (PDB IDs 2AZ5 and 9ILB, respectively) and their drug potential based on ADMET properties. The obtained results have demonstrated a significant decrease in blood glucose levels in mice through the reduction of TNF-α and IL-1β mediated diabetic processes, facilitated by the Rosa canina extract. In conclusion, this study exploring the effects of Rosa canina extracts on diabetic rats have provided valuable insights into its potential therapeutic benefits. The observed reductions in blood glucose levels, improvements in lipid profiles, and modulation of antioxidant activity highlight its promising role in managing diabetes-related complications. Further research is warranted to elucidate the underlying mechanisms and optimize the dosage regimens for harnessing the full therapeutic potential of Rosa canina extracts in diabetes management.

Emulsifying property, antioxidant activity, and bitterness of soybean protein isolate hydrolysate obtained by Corolase PP under high hydrostatic pressure

Enzymatic hydrolysis of proteins can enhance their emulsifying properties and antioxidant activities. However, the problem related to the hydrolysis of proteins was the generation of the bitter taste. Recently, high hydrostatic pressure (HHP) treatment has attracted much interest and has been used in several studies on protein modification. Hence, the study aimed to investigate the effects of enzymatic hydrolysis by Corolase PP under different pressure treatments (0.1, 100, 200, and 300 MPa for 1–5 h at 50 °C) on the emulsifying property, antioxidant activity, and bitterness of soybean protein isolate hydrolysate (SPIH). As observed, the hydrolysate obtained at 200 MPa for 4 h had the highest emulsifying activity index (47.49 m2/g) and emulsifying stability index (92.98 %), and it had higher antioxidant activities (44.77 % DPPH free radical scavenging activity, 31.12 % superoxide anion radical scavenging activity, and 61.50 % copper ion chelating activity). At the same time, the enhancement of emulsion stability was related to the increase of zeta potential and the decrease of mean particle size. In addition, the hydrolysate obtained at 200 MPa for 4 h had a lower bitterness value and showed better palatability. This study has a broad application prospect in developing food ingredients and healthy foods.

Comprehensive analysis of Mentha longifolia subsp. himalaiensis essential oil: GC MS profiling and biological properties

Mentha longifolia is a well-known species of medicinal plant for its ethnopharmacological, pharmacological importance, industrial uses etc. This research paper presents a comprehensive study on a new species Mentha longifolia subsp. himalaiensis essential oil, focusing on its GC-MS analysis, nematicidal and antioxidant activities, as well as in-silico PASS prediction. The essential oil was extracted from Mentha longifolia subsp. himalaiensis leaves using steam distillation and subjected to gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) analysis to identify its chemical composition. The in vitro nematicidal activities were accessed via nematode mortality assay and nematode egg hatching assay against Meloidogyne incognita. The essential oil was also tested for its antioxidant activities via DPPH (2,2-diphenyl-2-picrylhydrazyl) radical scavenging activity, H2O2 (Hydrogen peroxide) scavenging activity and Metal chelating activity. The essential oil was also tested for antimicrobial potential against 5 strains of bacteria and two strains of fungus. Furthermore, the major chemical constituents of the essential oils were subjected to in-silico PASS prediction for their biological activities. The GC and GC-MS analysis revealed that piperitenone oxide (31.13 %) and cis-piperitone oxide (51.61 %) were the major components of the essential oil. The essential oil exhibited significant nematicidal activity against M. incognita and notable antioxidant activity. The essential oils also showed significant antibacterial and antifungal activity against targeted microbial strains. In-silico PASS prediction further supported the essential oil's bioactive properties and its potential for diverse applications. These results highlight the potential of Mentha longifolia subsp. himalaiensis essential oil as a natural nematicide, antimicrobial and antioxidant agent.

Deciphering the chemical constituents of Phlomis monocephala extracts using UHPLC-HRMS and their antioxidant, neuroprotective, antidiabetic and toxic potentials

In the current study, five different extracts (n-hexane, ethyl acetate, dichloromethane, ethanol, and water) of Phlomis monocephala were analyzed for the first time by ultra-high-performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS) to identify their phenolic compounds. The extracts were also evaluated for their non-enzyme antioxidant activities using a variety of methods, including DPPH and, ABTS•+ scavenging activities, reduction of ferric (Fe3+), and cupric ions (Cu2+), metal chelating (MCA) activities, and phosphomolybdenum (PBD). Additionally, the extracts were assessed for their in vitro enzyme inhibition potential (acetylcholinesterase (AChE)/butyrylcholinesterase (BChE), α-amylase, α-glucosidase, and tyrosinase). Furthermore, cell viability was evaluated on HepG2 (human hepatocellular carcinoma), S17 cells (murine bone marrow stromal) and RAW (murine macrophages). UHPLC-HRMS allowed for the identification of 115 compounds from different chemical groups including flavonoids, iridoid glycosides, phenylethanoid glycosides and others. Most of the extracts had strong antioxidant potential and were rich in phenolic compounds. Ethanol and water extracts appear as the most promising antioxidant extracts providing the highest values followed by ethyl acetate by all the methodologies employed in this study. Furthermore, all the extracts, except the aqueous extract, inhibited all the enzymes significantly. Surprisingly, the aqueous extract did not show a prominent inhibition (low or no inhibition) against these enzymes. Hexane, ethyl acetate, and dichloromethane exhibited extremely significant cytotoxic effects against all cell lines at a higher concentration. The HepG2 cells demonstrated lower sensitivity to the extracts than RAW and S17 cells. In conclusion, P. monocephala can be considered as a valuable ingredient for the production of functional applications including nutraceuticals.

Siderophore-producing bacteria from Spitsbergen soils—novel agents assisted in bioremediation of the metal-polluted soils

Siderophores are molecules that exhibit a high specificity for iron (Fe), and their synthesis is induced by a deficiency of bioavailable Fe. Complexes of Fe-siderophore are formed extracellularly and diffuse through porins across membranes into bacterial cells. Siderophores can bind heavy metals facilitating their influx into cells via the same mechanism. The aim of the studies was to determine the ability of siderophore-producing bacteria isolated from soils in the north-west part of Wedel Jarlsberg Land (Spitsbergen) to chelate non-Fe metals (Al, Cd, Co, Cu, Hg, Mn, Sn, and Zn). Specially modified blue agar plates were used, where Fe was substituted by Al, Cd, Co, Cu, Hg, Mn, Sn, or Zn in metal-chrome azurol S (CAS) complex, which retained the blue color. It has been proven that 31 out of 33 strains were capable of producing siderophores that bind to Fe, as well as other metals. Siderophores from Pantoea sp. 24 bound only Fe and Zn, and O. anthropi 55 did not produce any siderophores in pure culture. The average efficiency of Cd, Co, Cu, Mn, Sn, and Zn chelation was either comparable or higher than that of Fe, while Al and Hg showed significantly lower efficiency. Siderophores produced by S. maltophilia 54, P. luteola 27, P. luteola 46, and P. putida 49 exhibited the highest non-Fe metal chelation activity. It can be concluded that the siderophores of these bacteria may constitute an integral part of the metal bioleaching preparation, and this fact will be the subject of further research.Graphical

Photoluminescent Carbon Quantum Dots from Dichrostachys glomerata Pods with Antioxidant and Cu2+ Chelating Properties

AbstractThis work presents the facile and single‐step hydrothermal synthesis of carbon quantum dots (CQDs) using the Dichrostachys glomerata extract as raw material. CQDs with the highest photoluminescence (PL) were obtained after heating the extract in 4 M NaOH at 200 °C for 7 h. The obtained CQDs exhibit an average size of ca. 4.7 nm, a green‐yellow PL emission independent on the excitation wavelength with contributions located at 478 and 562 nm, a monoexponential decay of their PL lifetime and a PL quantum yield of 18 %. These results indicate that the surface functionalization of sp2 clusters in CQDs is uniform. The antioxidant properties of CQDs were also investigated. CQDs can effectively reduce free radicals like superoxide or oxidants like KMnO4. Moreover, CQDs show a high Cu2+ chelating activity, which is attributed to the abundant carboxylate functions on their surface and may therefore be of high interest in therapeutic applications related to Cu2+ ions overload.

Secondary metabolic profiling, antioxidant potential, enzyme inhibitory activities and in silico and ADME studies: a multifunctional approach to reveal medicinal and industrial potential of Tanacetum falconeri

Tanacetum falconeri is a significant flowering plant that possesses cytotoxic, insecticidal, antibacterial, and phytotoxic properties. Its chemodiversity and bioactivities, however, have not been thoroughly investigated. In this work, several extracts from various parts of T. falconeri were assessed for their chemical profile, antioxidant activity, and potential for enzyme inhibition. The total phenolic contents of T. falconeri varied from 40.28 ± 0.47 mg GAE/g to 11.92 ± 0.22 mg GAE/g in various extracts, while flavonoid contents were found highest in TFFM (36.79 ± 0.36 mg QE/g extract) and lowest (11.08 ± 0.22 mg QE/g extract) in TFSC (chloroform extract of stem) in similar pattern as found in total phenolic contents. Highest DPPH inhibition was observed for TFFC (49.58 ± 0.11 mg TE/g extract) and TFSM (46.33 ± 0.10 mg TE/g extract), whereas, TFSM was also potentially active against (98.95 ± 0.57 mg TE/g) ABTS radical. In addition, TFSM was also most active in metal reducing assays: CUPRAC (151.76 ± 1.59 mg TE/g extract) and FRAP (101.30 ± 0.32 mg TE/g extract). In phosphomolybdenum assay, the highest activity was found for TFFE (1.71 ± 0.03 mg TE/g extract), TFSM (1.64 ± 0.035 mg TE/g extract), TFSH (1.60 ± 0.033 mg TE/g extract) and TFFH (1.58 ± 0.08 mg TE/g extract), while highest metal chelating activity was recorded for TFSH (25.93 ± 0.79 mg EDTAE/g extract), TFSE (22.90 ± 1.12 mg EDTAE/g extract) and TFSC (19.31 ± 0.50 mg EDTAE/g extract). In biological screening, all extracts had stronger inhibitory capacity against AChE while in case of BChE the chloroform extract of flower (TFFC) and stem (TFSC) showed the highest activities with inhibitory values of 2.57 ± 0.24 and 2.10 ± 0.18 respectively. Similarly, TFFC and TFSC had stronger inhibitory capacity (1.09 ± 0.015 and 1.08 ± 0.002 mmol ACAE/g extract) against α-Amylase and (0.50 ± 0.02 and 0.55 ± 0.02 mmol ACAE/g extract) α-Glucosidase. UHPLC-MS study of methanolic extract revealed the presence of 133 components including sterols, triterpenes, flavonoids, alkaloids, and coumarins. The total phenolic contents were substantially linked with all antioxidant assays in multivariate analysis. These findings were validated by docking investigations, which revealed that the selected compounds exhibited high binding free energy with the enzymes tested. Finally, it was found that T. falconeri is a viable industrial crop with potential use in the production of functional goods and nutraceuticals.

Contribution of Phenolic Compounds to the Antioxidant Activity of Leaf and Flower Extracts of Sinapis pubescens L. subsp. pubescens (Brassicaceae).

Within a study focused on Sinapis pubescens subsp. pubescens wild from Sicily (Italy), an edible species still unexplored, our earlier published work has demonstrated good in vitro antioxidant properties for the flower and leaf hydroalcoholic extracts, exhibiting quite different qualitative-quantitative phenolic profiles. Herein, further research was designed to elucidate the role played by phenolic compounds in the different antioxidant mechanisms highlighted for the extracts. To achieve this goal, the crude extracts were subjected to liquid-liquid partitioning with solvents of increasing polarity; then, the fractions were investigated for their antioxidant properties using different in vitro assays. For both flowers and leaves, the ethyl acetate fractions exhibited the best activity in DPPH and reducing power assays, followed by n-butanol. The total phenolic content determination indicated these fractions as the phenolic-rich ones, which were characterized by HPLC-PDA/ESI-MS analysis. Conversely, the phenolic-rich fractions did not show any chelating activity, which was highlighted for the more hydrophobic ones.

Effects of Extraction Methods on the Physicochemical Properties and Biological Activities of heteroglycans from Hibiscus sabdariffa calyx

The hot-water extraction method has been employed to enhance the diffusion rate of heteroglycans, thereby augmenting the extraction efficiency. This study investigates the antioxidant activities and immunological properties of water-soluble polysaccharides derived from the Hibiscus sabdariffa calyx (HWPF and LWPF). These polysaccharides were isolated through two distinct extraction methods involving hot water followed by ethanol precipitation. The physicochemical characterization was conducted through a series of experiments encompassing monosaccharide composition, ultraviolet-visible spectrum analysis, and Fourier-transform infrared (FT-IR) spectroscopy. The evaluation of antioxidative properties employed various techniques, including DPPH and ABTS radical scavenging activities, Ferric Reducing Antioxidant Power, ferrous chelating power, total reducing power, and protection against DNA damage. The assessment of anti-inflammatory potential involved the inhibition of hemolytic activity induced by a hypotonic solution and heat. Furthermore, the impact of the polysaccharides on the production of pro-inflammatory cytokines was analyzed through Luminex assay and RTPCR assay in PBMCs and LPS-stimulated RAW 264.7 cells, respectively. The findings revealed that heteroglycans (LWPF and HWPF) exhibit a content of Ara-Man-Rha-GluA-GalA (41.2:17.2:15.7:9.2:8.8) and Ara-Glu-Rha-Xyl-GluA-Man (31.5:23.8:12.16:10.4:7:6) with molecular weights of approximately 4.5 KDa and 41.3 KDa, respectively. HWPF demonstrated robust metal chelating and scavenging activities. Additionally, each fraction exhibited substantial protection of DNA against damage induced by H2O2. LWPF was observed to significantly down-regulate the expression of pro-inflammatory cytokines IL-6 and COX-2 at both transcriptional and translational levels, along with inhibiting NO production. In summary, these results indicate that the choice of extraction methods influences both the structure and biological activities of heteroglycans, providing valuable insights into the structure-activity relationship.&#x0D; Keywords: Hibiscus sabdariffa, heteroglycans, hot water extraction, physicochemical properties, Antioxidant activity, Pro-inflammatory cytokines.

Heteroglycan of Annona muricata leaves: Extraction, characterization, modulation of the inflammatory response in raw 264.7 macrophages and peripheral Blood mononuclear cells

The natural products contained in Annona muricata leaves are characterized by their ability to effectively enhance the immune response without exhibiting toxicity. The immunomodulatory effect of natural polysaccharides is considered one of the most important bioactive functions. In this study, we investigated the antioxidant activities and immunological properties of heteroglycans extracted from A. muricata leaves using hot water followed by ethanol precipitation. The polysaccharide was characterized for its physicochemical properties (UV spectroscopy, FTIR, gas chromatography), antioxidant potential (scavenging properties, chelating ability, reducing capability, and protection against DNA damage), immunomodulatory activities, and production of pro-inflammatory cytokines using peripheral blood mononuclear cells (PBMCs) and RAW 264.7 cells. The results indicated that the heteroglycans consisted of Glu-Man-GalA-GluA-Xyl and GluA-Man-Glu, respectively, for low and high molecular weight water-soluble polysaccharides coded as LWPC and HWPC. They exhibited strong metal chelating and scavenging activities. Additionally, each sample provided protection against DNA damage induction, with LWPC exhibiting up to 73.1 % protection. LWPC and HWPC significantly down-regulated the expression of pro-inflammatory cytokines TNF-α, IL-1β, IL-6, and COX-2, as well as NO production. At 200 µg/mL, only LWPC increased the production of IL-1β and IL-6 in PBMCs. Therefore, LWPC and HWPC hold promise for inhibiting radical-induced and inflammatory disorders.

Iron regulatory protein from the hard tick Haemaphysalis longicornis: characterization, function and assessment as a protective antigen.

Ticks are blood-feeding ectoparasites with different host specificities and are capable of pathogen transmission. Iron regulatory proteins (IRPs) play crucial roles in iron homeostasis in vertebrates. However, their functions in ticks remain poorly understood. The aim of the present study was to investigate the characteristics, functions, molecular mechanisms, and the vaccine efficacy of IRP in the hard tick Haemaphysalis longicornis. The full-length complementary DNA of IRP from Haemaphysalis longicornis (HlIRP) was 2973 bp, including a 2772 bp open reading frame. It is expressed throughout three developmental stages (larvae, nymphs, and adult females) and in various tissues (salivary glands, ovaries, midgut, and Malpighian tubules). Recombinant Haemaphysalis longicornis IRP (rHlIRP) was obtained via a prokaryotic expression system and exhibited aconitase, iron chelation, radical-scavenging, and hemolytic activities in vitro. RNA interference-mediated IRP knockdown reduced tick engorgement weight, ovary weight, egg mass weight, egg hatching rate, and ovary vitellin content, as well as prolonging the egg incubation period. Proteomics revealed that IRP may affect tick reproduction and development through proteasome pathway-associated, ribosomal, reproduction-related, and iron metabolism-related proteins. A trial on rabbits against adult Haemaphysalis longicornis infestation demonstrated that rHlIRP vaccine could significantly decrease engorged weight (by 10%), egg mass weight (by 16%) and eggs hatching rate (by 22%) of ticks. The overall immunization efficacy using rHlIRP against adult females was 41%. IRP could limit reproduction and development in Haemaphysalis longicornis, and HlIRP was confirmed as a candidate vaccine antigen to impair tick iron metabolism and protect the host against tick infestation. © 2024 Society of Chemical Industry.

Effects of three polyphenols with different numbers of phenolic hydroxyls on the structural and interfacial properties and lipid-protein co-oxidation of oil body emulsions

Oil bodies (OBs) are organelles for storing lipids, and they are composed of lipid cores and monolayer phospholipid protein membranes. During storage, membrane proteins anchored in the lipid core are often damaged by lipid oxidation products, leading to oxidative damage and a decreased quality of emulsified foods. Here, three natural antioxidants (gallic acid (GA), epigallocatechin gallate (EGCG), and tannic acid (TA)) were added to OB emulsions to study the effects of polyphenols on protein interfacial properties during oxidation and the lipid-protein co-oxidation behavior. Compared to GA, EGCG and TA with higher molecular weights and hydroxyl substitution showed better antioxidant activity, metal chelating activity, iron reduction ability, and affinity for OB. The polyphenols significantly reduced the contents of free amino and sulfhydryl groups in OB. Infrared spectroscopy analysis indicate that hydrogen bonding and hydrophobic interactions may exist between the polyphenols and OB. During storage, polyphenols inhibited >23% of the primary and secondary lipid oxidation products in the emulsions, whereas the formation of carbonyl groups and disappearance of sulfhydryl groups were only inhibited by 10.7% and 7.4%, respectively, indicating that polyphenols preferentially inhibited lipid oxidation over protein oxidation. Electrophoresis results showed that moderate oxidation (3 days of storage) disrupted the disulfide bonds of proteins. Note that moderate oxidation enhanced the interfacial properties of OB proteins, whereas excessive oxidation led to protein aggregation. This study offers new perspectives on using polyphenols to regulate the lipid-protein co-oxidation in OB, as well as the different properties of OB proteins after oxidation.

Chemical characterization and antioxidant activities of essential oil of Ficus elastica Roxb. ex Hornem. leaves

The present study investigates the chemical constituents and antioxidant potential of essential oils extracted from Ficus elastica. The essential oils were obtained through steam distillation and were subjected to gas chromatography-mass spectrometry (GC-MS) analysis to determine their constituents representing 100% of the total peak areas. The analysis revealed the presence of 34 compounds. Among these compounds, Caryophyllene was found to be the major constituent, accounting for 50.57% of the total percentage area. Among other identified major compounds include γ-Muurolene (8.19%), camphene (5.69%), Heptacosane (2.61%), and Heneicosane (2.60%). Furthermore, the antioxidant potential of Ficus elastica essential oil was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydrogen peroxide radical scavenging methods. The results indicated that F. elastica’s essential oil exhibited significant radical scavenging activity when compared to the standard antioxidant, Ascorbic acid. For the highest concentration tested (10 μL/mL), the DPPH scavenging inhibition percentage was 45.26% for F. elastica and 90.40% for Ascorbic acid. Similarly, the hydrogen peroxide scavenging activity at 10 μL/mL was found to be 74.90% for F. elastica and 90.12% for Ascorbic acid. Additionally, the essential oils demonstrated high radical scavenging and chelating activity. The quantitative DPPH and hydrogen peroxide assays indicate the potent antioxidant activity of F. elastica essential oil, making it a promising candidate for further biological and chemical analysis. The isolation of therapeutically active compounds from these essential oils can be pursued, considering their potential role in the management and treatment of various diseases.

Genome-based approach to evaluate the metabolic potentials and exopolysaccharides production of Bacillus paralicheniformis CamBx3 isolated from a Chilean hot spring.

In the present study, a thermophilic strain designated CamBx3 was isolated from the Campanario hot spring, Chile. Based on 16S rRNA gene sequence, phylogenomic, and average nucleotide identity analysis the strain CamBx3 was identified as Bacillus paralicheniformis. Genome analysis of B. paralicheniformis CamBx3 revealed the presence of genes related to heat tolerance, exopolysaccharides (EPS), dissimilatory nitrate reduction, and assimilatory sulfate reduction. The pangenome analysis of strain CamBx3 with eight Bacillus spp. resulted in 26,562 gene clusters, 7,002 shell genes, and 19,484 cloud genes. The EPS produced by B. paralicheniformis CamBx3 was extracted, partially purified, and evaluated for its functional activities. B. paralicheniformis CamBx3 EPS with concentration 5 mg mL-1 showed an optimum 92 mM ferrous equivalent FRAP activity, while the same concentration showed a maximum 91% of Fe2+ chelating activity. B. paralicheniformis CamBx3 EPS (0.2 mg mL-1) demonstrated β-glucosidase inhibition. The EPS formed a viscoelastic gel at 45°C with a maximum instantaneous viscosity of 315 Pa.s at acidic pH 5. The present study suggests that B. paralicheniformis CamBx3 could be a valuable resource for biopolymers and bioactive molecules for industrial applications.

Metal‐chelating antioxidant peptides: Biosensor screening methods as alternatives to the ferrozine assay

AbstractPreventing metal‐catalyzed lipid oxidation in food products, which decreases nutritional value and sensory quality, is crucial in the food industry. This is typically achieved through the use of metal‐chelating molecules. While the ferrozine assay is widely used to screen protein hydrolysates for metal chelating activity, it has proven difficult to use with pure peptides. This study evaluates the potential of surface plasmon resonance (SPR) and electrically switchable nanolever technology (switchSENSE®) as alternative screening methods. Unfortunately, solubility issues and large standard deviations precluded a direct correlation between the ferrozine assay and these biosensor techniques. Both techniques, however, were able to quantitatively distinguish between two peptides with very similar sequences despite the absence of a correlation between dissociation constants determined by SPR and switchSENSE®. This study highlights the potential of SPR and switchSENSE® for screening the metal chelating activity of pure peptides, advancing the understanding of peptide‐metal ion interactions.

Chemical profiling and in-vitro anti-oxidant, anti-diabetic, anti-inflammatory, anti-bacterial and anti-fungal activities of essential oil from Rosmarinus officinalis L.

Rosmarinus officinalis L. commonly known as Rosemary is a well-known genus belongs to Lamiaceae family, which is one of the major plant families with a high concentration of essential oils. Rosemary is well known to produce herbal essential oils owing to the presence of therapeutic and medicinal elements in the plant’s by-products. In the present study, rosemary essential oil (REO) was extracted from Rosmarinus officinalis and it was evaluated for its phytochemicals, antioxidant, antibacterial, antifungal, anti-diabetic and anti-inflammatory activities. GC-FID analysis and fingerprint analysis was performed. Different antioxidant assays were performed like DPPH (1,1-diphenyl-2-picrylhydrazyl), ABTS (2,2-azinobis-3-ethylbenzothiazoline-6-sulphonic acid), nitric oxide radical, hydroxyl radical, iron reducing potential, iron chelating activity. Anti-bacterial activity was observed by the disk diffusion method against Gram-positive (G+), Gram-negative (G−) bacteria. Anti-diabetic and anti-inflammatory activities were also performed. Antifungal activity against Aspergillosis and Mucormycosis causing fungal strains was also evaluated. GC-FID revealed the presence of vertocitral, α-pinene andhumulene oxidemajor component of REO along with other bioactive components. The IC50 value (µl/ml) for various assays was observed in the following order: OH- (16.6118), iron chelating (32.0115), iron reducing (92.534), DPPH (101.929), and ABTS (172.2765). The best antimicrobial activity was against Bacillus subtilis (MTCC 121), with an inhibition zone of 2.5 cm. REO showed strong anti-inflammatory and anti-diabetic potential and can be employed as an anti-diabetic agent due to its inhibitory effect on α-amylase activity. Based on these findings it was concluded that REO can be widely employed across a variety of sectors, including food, aromatherapy, herbal and allopathic medicine, cosmetics, and as a natural biocide, fungicide, and preservative.

Characterization of the antioxidant activity, identified free radical-relieving components by LC/QTOF/MS and acute oral toxicity studies of Tri-Tharn-Thip tea

This study assessed the antioxidant activities and bioactive maker of Tri-Than-Thip tea (Tri-TTa) to provide database support for the use of Tri-Than Thip remedy according to the Thai Pharmaceutical Textbook and aims to develop herbal medicine or food from natural products. Tri-TTa and herbal components were tested for antioxidant scavenging activity (DPPH assay, ABTS assay), chain-breaking/iron ion chelating activity (Metal Chelating Activity; MAC, the ferric-reducing antioxidant power activity; FRAP), superoxide anion radical scavenging activity (NBT assay), oxygen radical antioxidant capacity (ORAC assay), total content of Phenolic (TCP) and flavonoid (TCP) substance. The chemical components were separated and investigated by LC/QTOF/MS for safe dosages due to acute oral toxicity in rats. The Tri-TTa showed the strongest inhibition of antioxidant activity with the DPPH, ABTS, and MCA assay, with IC50 values of 0.087 ± 0.003, 0.025 ± 0.000, and 0.012 ± 0.000 mg/mL, respectively. In addition, Tri-TTa can also inhibit superoxide anion radicals, with IC50 values of 158 ± 0.009 mg/mL, and the oxygen radical was 3.47 ± 0.03 μM of TE/g extract. TCP, TCF, and FRAP values of Tri-TTa were 154.123 ± 1.326, 80.233 ± 14.268 mg equivalent/g of extract, and 1092.457 ± 106.024 mM FeSO4/mg, respectively. Additionally, Tri-TTa contains important substances in the phenolic and flavonoid groups that have good antioxidant abilities and were confirmed to be safe through acute oral toxicity testing in rats, which revealed no toxicity-related effects at high doses. Tri-TTa is a strong candidate for use as a natural product with antioxidant activity, suggesting that plant polyphenol content may promote antioxidant activity. These results support further research on Thai folk remedy infusions as promising antioxidant agents that can be developed for food, tea, or tonic drugs from natural.