Daucosterol (DAU) was isolated from the methanol-chloroform crude extract of six Nepeta species (N. aristata, N. baytopii, N. italica, N. nuda albiflora, N. stenantha and N. trachonitica) using ...sephadex and silica-gel columns via bioactivity-guided isolation. Spectroscopic methods and comparisons with similar data in the literature determined its structure. DAU was evaluated for enzyme inhibitions, kinetics, DNA protection, and molecular interactions. The inhibition activities of AChE, tyrosinase, BChE, and urease were found to be 21.32±1.24, 3.17±0.45, 16.73±0.10 and 12.95±0.21 μM, respectively. The Ki values of the inhibition kinetics of the same enzymes were observed as 0.11, 0.05, 0.12, and 0.12 mM, respectively. DAU exhibited effective protection activity against DNA damage induced by H2O2 and ultraviolet radiation in DNA protection tests. DFT analysis showed low hardness and high softness values. The best binding affinity of DAU was achieved by the enzymes AChE and BChE (for both: −9.90 kcal/mol). As a result of the interaction of standards and DAU with enzymes, it was observed that DAU bound with a higher potential than the standards. Molecular dynamics simulations of these enzymes were examined for 100 ns, and the energy results of the simulation were determined by MM/PBSA calculation in the last 10 ns. Additionally, its pharmacokinetic properties were investigated with SwissADMET, and it was noted that it had low toxic effects and gastrointestinal absorption.
Thus, in vitro and in silico analysis determined that the DAU molecule could protect against DNA oxidative damage and an active metabolic enzyme inhibitor.
Display omitted
•Daucosterol was isolated from six different Nepeta species by activity-guided isolation•Daucosterol had potent enzyme inhibition and DNA protection activities•Urease inhibition kinetics and molecular interactions of daucosterol were studied for the first time•Daucosterol exhibited favorable binding constants and affinities with BChE and tyrosinase.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
RAD51 and the breast cancer suppressor BRCA2 have critical functions in DNA double-strand (dsDNA) break repair by homologous recombination and the protection of newly replicated DNA from nucleolytic ...degradation. The recombination function of RAD51 requires its binding to single-stranded DNA (ssDNA), whereas binding to dsDNA is inhibitory. Using reconstituted MRE11-, EXO1-, and DNA2-dependent nuclease reactions, we show that the protective function of RAD51 unexpectedly depends on its binding to dsDNA. The BRC4 repeat of BRCA2 abrogates RAD51 binding to dsDNA and accordingly impairs the function of RAD51 in protection. The BRCA2 C-terminal RAD51-binding segment (TR2) acts in a dominant manner to overcome the effect of BRC4. Mechanistically, TR2 stabilizes RAD51 binding to dsDNA, even in the presence of BRC4, promoting DNA protection. Our data suggest that RAD51’s dsDNA-binding capacity may have evolved together with its function in replication fork protection and provide a mechanistic basis for the DNA-protection function of BRCA2.
Display omitted
•Specific interactions between nucleases and RAD51 are not required for DNA protection•Single-stranded DNA overhangs are dispensable for DNA protection•BRC4 repeat of BRCA2 abrogates the DNA-protection capacity of RAD51•TR2 domain of BRCA2 restores DNA protection in the presence of BRC4
Halder et al. show that RAD51 protects nascent DNA from unscheduled nucleolytic degradation through its binding to double-stranded DNA. The recombination-independent function of BRCA2 is stimulated by the C-terminal fragment of the breast cancer suppressor BRCA2.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Ethnopharmacological relevance; Several plant species of Miconia genus are commonly used in Brazilian folk medicine as anti-inflammatory agents and for the treatment of infectious diseases. Infusions ...and extracts of Miconia species are also reported as analgesic, antimicrobial, antimalarial, antioxidant, anti-inflammatory, antinociceptive, antimutagenic, and antitumoral.
Aim of the study; To determine the phytochemical composition of an aqueous extract of Miconia latecrenata leaves and to evaluate its antioxidant, antibacterial, antimutagenic and antigenotoxic activities.
Materials and Methods; The following methods were used for the different effects: I) antioxidant - β-carotene/linoleic acid, lipid peroxidation, and DPPH• radical scavenging; II) antibacterial - agar well diffusion and MIC methods); III) antimutagenic assays - Ames Test; and IV) antigenotoxic - Plasmid cleavage test. The phytochemical analysis and phenolic quantification were carried out by UPLC-DAD-ESI-MS/MS and colorimetry, respectively. In addition, statistical correlation analysis was performed aiming to evaluate the Pearson correlation between phenolic compounds and biological assays.
Results; A high content of tannins was observed and the ellagitannin isomers of 1,2,3,5-tris-galloyl-4,6-HHDP-glucose were identified as the main constituents of the leaves aqueous extract. High antioxidant effect, in different tests, high antibacterial activity to gram-positive and negative strains, as well as high antimutagenic activity were observed. Statistical analysis showed a high Pearson correlation for the tannin content in relation to the results of the antioxidant and antibacterial tests. In general, the antioxidant action of the aqueous extract showed low correlation with the antimutagenic activity.
Conclusions; The present results confirmed the expectations regarding the pharmacological profile of M. latecrenata supporting its therapeutic potential in relation to ROS/RNS related disorders. Furthermore, the phenolic compounds of M. latecrenata can act, in turn, minimizing or inhibiting the biological macromolecules damage, especially DNA.
Display omitted
•Natural phenolic compounds can reducing damage in biological macromolecules.•Aqueous extract of Miconia latecrenata leaves (EML) show high antioxidant action.•EML show high antibacterial action for gram positive and negative strains.•EML show high antimutagenic activity in the different strains in Ames test.•EML show correlation of phenolic compounds with antioxidant and antibacterial tests.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Glyphosate is a controversial herbicide. Its genotoxicity and presence in various ecosystems have been reported. The use of ascorbic acid and resveratrol could protect different organisms from ...glyphosate-induced genetic damage. In the present study, specific genetic damage induced by glyphosate was evaluated in erythrocytes of Oreochromis niloticus, Ambystoma mexicanum and human lymphocytes. Simultaneously, the antigenotoxic capacity of various concentrations of ascorbic acid and resveratrol was evaluated by means of pretreatment and simultaneous treatment protocols. The 0.03, 0.05 and 0.07 mM concentrations of glyphosate induced significant genotoxic activity (p < 0.05) in human lymphocytes and in erythrocytes of the species studied, and could cause genomic instability in these populations. The reduction in genetic damage observed in human lymphocytes exposed to high concentrations of glyphosate is only apparent: excessive genetic damage was associated with undetectable excessive tail migration length. A significant (p < 0.05) antigenotoxic effect of ascorbic acid and resveratrol was observed in all concentrations, organisms and protocols used. Both ascorbic acid and resveratrol play an important role in maintaining the integrity of DNA. Ascorbic acid in Oreochromis niloticus, Ambystoma mexicanum reduced glyphosate-induced genetic damage to a basal level. Therefore, our data indicate that these antioxidants could help preserve the integrity of the DNA of organisms exposed to glyphosate. The consumption of antioxidants is a useful tool against the genotoxicity of glyphosate.
Display omitted
•Miniferritins are widely spread across Prokarya, with over 3000 current annotations.•Predominantly expressed upon starvation or under acute oxidative stress conditions.•Bimodal DNA ...protection through direct shielding coupled to iron and ROS detoxification.•Ferroxidation is followed by the accumulation of a mineral iron core of up to 500 atoms.•Vast potential for nanotechnology and biomedicine applications.
The subject of this review article was first reported approximately three decades ago upon the discovery of a starvation-inducible protein found tightly bound to chromosomal DNA in 3-day-old starved cultures of Escherichia coli. As a result, they were named “DNA-binding protein from starved cells” or Dps. Recognized by their homology to ferritins, these proteins were classified as a new branch of the Ferritin-like proteins superfamily and designated as miniferritins. These proteins present a cage-like structure built by twelve identical four-helix bundle monomers. They are capable of performing fast oxidation of ferrous ions using hydrogen peroxide, while still retaining the possibility of using molecular oxygen as co-substrate, and subsequently accumulating ferric ions in its cavity in a ferric mineral form. This complex catalytic activity is designed to protect cells from oxidative stress conditions, reducing the risk of harmful oxygen radical species being formed in particular physiological conditions. They are also capable of binding to and compacting DNA, becoming the most abundant nucleoid protein in the stationary phase, adding physical protection to the chemical protection attained by the ferroxidation reaction. Miniferritins are almost ubiquitous to Bacteria and Archaea, with protein characterization reported for over 60 microorganisms and several thousands of homologous genes annotated in current genomic databases, which demonstrates the importance of these proteins in Prokarya. In this manuscript we offer an extensive, yet concise, description of the state of the art on miniferritins, including their regulation, the global structural features, metal center characterization, diverse functional properties and the current stage of multifaceted biotechnological applications.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Display omitted
•Simulated digestion enhances antioxidant activity of cashew nut flour compounds.•Digested soluble fraction of the cashew nut flour showed DNA protection.•Undigested fraction of the ...cashew nut flour showed potential prebiotic effect.•Cashew nut flour positively stimulated B. animalis BB-12 proliferation.
Cashew nuts are mainly consumed as a roasted and salted snack. Lately, the industry has gained interest in broken kernels because of their added value. In this study, defatted cashew nut flour (DCF) underwent simulated gastrointestinal digestion to obtain a soluble (CDs) and an insoluble (CDi) digested fraction. These fractions, which resulted from the digestion of a complex matrix, were evaluated for antioxidant capacity of bioaccessible compounds (present on the soluble digested fraction, CDs) and their potential prebiotic effect, considering that the insoluble digested fraction (CDi) could be fermented by the microbiota in the gut. The DCF had a high protein content (40.74%), being nutritionally characterized as a balanced source of amino acids, with a predominance of aromatic amino acids (phenylalanine and tyrosine), threonine and histidine. The digested DCF presented 76.90% of the soluble components of low molecular weight (0.1–2 kDa), which is typical of antioxidant peptides. The soluble digested fraction (CDs) significantly increased the antioxidant capacity in relation to flour in the ORAC and ABTS assays and the aqueous extract presented the highest values (526.0 and 76.64 as µmol Trolox Eq./g sample, respectively). The CDs protected 29.03% of the supercoiled DNA band and ratified the potential antioxidant capacity after GID in a physiological assay. In addition, the insoluble digested fraction showed a potential prebiotic effect for Bifdobacterium lactis BB-12. Finally, simulated gastrointestinal digestion improves the bioaccessibility of CDF antioxidant compounds as a complex matrix, containing low molecular weight peptides and phenolic compounds, which become more available to react with reactive oxygen species (ROS). In addition, the potential prebiotic effect of defatted cashew nut flour has yielded a promising solution for the total reuse of broken cashew nut kernel as a functional food ingredient.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Bidens tripartita L. is a traditional phyto-remedy used in several countries, yet there is still a paucity of data on its biological potential. We aimed to provide new insights on the pharmacological ...potential of extracts prepared from B. tripartita via highlighting its antioxidant, key enzymes inhibitory potency, and DNA protecting effects. Phytochemical profile was established using High-Performance Liquid Chromatography with Diode-Array Detection (HPLC-DAD) and bioactive compound(s) docked against target enzymes using in silico methods. Cytotoxicity against three cancer cell lines was assessed using the methylthiazolyldiphenyl-tetrazolium bromide (MTT) cell viability test. The main compounds were luteolin-7-glucoside (cynaroside), chlorogenic acid, and epicatechin in the extracts. The methanol extract exhibited the highest radical scavenging activity. Ethyl acetate extract showed strongest α-amylase inhibitory activity, while the best α-glucosidase inhibitory effect recorded for the methanol extract. Molecular docking showed that cynaroside strongly interact to α-glucosidase cavity by establishing six hydrogen bonds. B. tripartita extracts were found to protect supercoiled form of pUC19 plasmid (>70%) and also showed anti-proliferative properties. Results amassed in the present study add on to a growing body of literature on the multi-pharmacological potency of B. tripartita which can be applied to bio-products development geared towards management of common diseases.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Natural antioxidants, like phenolic acids, possess a unique chemical space that can protect cellular components from oxidative stress. However, their polar carboxylic acid chemotype reduces full ...intracellular antioxidant potential due to limited diffusion through biological membranes. Here, we have designed and developed a new generation of hydrophobic turn-on fluorescent antioxidant precursors that upon penetration of the cell membrane, reveal a more polar and more potent antioxidant core and simultaneously become fluorescent allowing their intracellular tracking. Their activation is stimulated by polarity alteration by sensing intracellular signals and specifically biothiols. In our design, the carboxylic group of phenolic acids that originally restricts cell entrance is derivatized and conjugated through Copper (I)-catalyzed azide-alkyne cycloaddition (CuAAC) to a coumarin derivative that its fluorescence properties are quenched with a biothiol activatable element. This more hydrophobic precursor readily penetrates cell membrane and once inside the cell the antioxidant core is revealed upon sensing glutathione, its fluorescence is restored in a turn-on manner and the generation of a more polar character traps the molecule inside the cell. This turn-on fluorescent antioxidant precursor that can be applied to phenolic acids, was developed for rosmarinic acid and the conjugate was named as RCG. The selectivity and responsiveness of RCG towards the most abundant biothiols was monitored through a variety of biophysical techniques including UV–Vis, fluorescence and NMR spectroscopy. The electrochemical behavior and free radical scavenging capacity of the precursor RCG and the active compound (RC) was evaluated and compared with the parent compound (rosmarinic acid) through cyclic voltammetry and EPR spectroscopy, respectively. The stability of the newly synthesized bioactive conjugate RC was found significantly higher than the parent rosmarinic acid when exposed to oxygen. Cell uptake experiments were conducted and revealed the internalization of RCG. The degree of intracellular DNA protection offered by RCG and its active drug (RC) on exposure to H2O2 was also evaluated in Jurkat cells.
Display omitted
•Development of a turn-on fluorescent antioxidant precursor of phenolic acids (RCG).•The electrochemical oxidation profile was revealed with cyclic voltametry.•Free radical scavenging activity was evaluated with EPR spectroscopy.•GSH triggers the release of the active compound.•RCG offers DNA protection against oxidative stress.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•Comparative study with various substituted OCs for structure-function relationship.•Synthesis and Characterization of novel oxacalix4arene (OC) materials.•Biological potency screening of OC by MTT ...assay, UV–Vis and gel electrophoresis.•Antioxidant activity of OC by DPPH assay.•OC as DNA protector as well as DNA cleavage agent.
Calixarene, a third generation supramolecule, have made their signature in biomedical applications through their unique physicochemical characteristics. Oxacalixarene, a class of heteracalixarene, is less explored in this respect though it has manifested its potentiality in earlier very few reports. Here we are reporting for the first time a systematic and comparative study of biological activities of different oxacalix4arene(OC) systems. For this purpose, very common functional groups that are available in biomacromolecules like phenolic OH (DHOC), amine (DNOC), ester (DEOC) and amide (DAOC) have been considered for functionalization to basic OC platform and the newly synthesized compounds are characterized with state-of-the-art spectroscopic techniques. Analysis of DNA cleavage, DNA binding, cell cytotoxicity and antioxidant activity studies nicely define the diversity of OC in DNA protection or DNA damage phenomena. DHOC is able to protect oxidative cleavage of DNA up to 47 % against Fenton reagents. The order of binding constant (∼105) is observed in the following order: DHOC (phenolic OH) > DNOC (amine) > DAOC (amide). The article also reports the antioxidant activity of oxacalix4arene compounds for the first time, observed by DPPH inhibition assay. All the compounds possess antioxidant activities. Among those, DHOC shows maximum antioxidant activity, comparable to standard antioxidant ascorbic acid at 100 µM (DPPH: 60 µM). Indeed, the observed structure-function relationship of OC systems can be tailored in the future to design molecules that are specifically targeted for biomedical applications.
Display omitted
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Display omitted
•In vitro digestion causes phenolic-peptide complex formation in processed cowpeas.•In vitro digestion increases radical scavenging activity of processed cowpea beans.•Digests from ...processed cowpeas inhibit endotoxin-induced cellular NO production.•Digests from processed cowpeas protect DNA and fibroblasts from oxidative damage.
The effect of simulated in vitro upper gut digestion on the phenolic composition and antioxidant properties of processed cowpea beans was studied. The samples comprised four cowpea cultivars: a cream, brownish-cream and two reddish-brown cultivars. Dry cowpea seeds were soaked in water, blended into paste and deep-fried in vegetable oil. The fried samples were taken through in vitro upper gut digestion followed by freeze-drying of the supernatant. Phenolic composition of extracts from the supernatants were determined using HPLC-MS. Radical scavenging activities were documented using the TEAC, ORAC and nitric oxide (NO) assays. In vitro digestion of the processed cowpeas resulted in phenolic-peptide complexes that were identified for the first time, and decreased extractable phenolic compounds. However, the radical scavenging activities increased. The processed cowpeas and their digests inhibited cellular NO production, and oxidative DNA and cellular damage. In conclusion, deep-fried cowpeas when consumed, could potentially help alleviate oxidative stress-related conditions.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
PDF
