H2O2 Assay Research Articles

Denatured proteins show new vitality: Green synthesis of germanium oxide hollow microspheres with versatile functions by denaturing proteins around bubbles

AbstractThe hollow structure has long attracted great attention because of its excellent properties. However, this special structure is usually synthesized through some complex approaches. Herein, we discovered that denatured bovine serum albumin (BSA) can trigger unusual biomineralization for the simple, green and shape‐controllable synthesis of germanium oxide (GeOx) hollow microsphere (HMS). At high temperature (60°C), BSA was denatured, and a compact BSA layer was formed around the H2 bubbles. The denatured BSA layer was stable and suitable for anchoring and growing GeOx. By simply changing the BSA concentration and temperature, various morphologies of GeOx could be obtained. Due to the denatured protein skeletons and microenvironment‐regulated collapse, GeOx HMS showed great potential for intelligently responsive pesticide delivery in the insect gut, showing superiority over traditional delivery systems, which early release pesticides in the mouth and stomach. Inspired by its large specific surface area, excellent biocompatibility, modifiable functional groups, and high electrocatalytic activity, GeOx HMS was also applied to versatile sensors for H2O2 assays at physiological pH and rapid coronavirus COVID‐19 detection. This work not only provides some evidence for understanding proteins in depth but also paves a new avenue for the biomineralization‐inspired synthesis of hollow structures with versatile functions.

Bioactivity study and metabolic profiling of Colletotrichum alatae LCS1, an endophyte of club moss Lycopodium clavatum L.

Endophytes are silent microbial partners of green plants that ensure hosts’ survival in odd conditions. They are known as the factories of multipotent metabolites with diverse bioactivities beneficial to modern pharmaceuticals industry. Endophytic fungi have been screened from a variety of plants and it is the first-time endophytes of club moss is being studied for production of antibacterial and antioxidative compounds. The present study reveals that Lycopodium clavatum L. harbors a potent niche of bioactive endophytic fungi and Colletotrichum alatae LCS1 was the prime producer of antibacterial and antioxidative compounds among them. The minimum inhibitory and bactericidal concentrations of ethyl- acetate culture extract ranged from 15.62 to 250 μg/mL against four Gram negative and three Gram positive microorganisms including methicillin resistant Staphylococcus aureus (ATCC-33591). Bio-autogram based screening followed by Gas chromatographic analysis confirmed the occurrence of 17 bioactive compounds and α-bisabolol is known to be the prime one. Alfa bisabolol is a unique and versatile bioactive essential oil and facilitates variety of functions. Killing kinetics data along with leakage of macromolecules into extracellular environment supports the cidal activity of the antibacterial principles at MBC values. Isolate C. alatae LCS1 was optimized by one variable at a time system coupled with response surface methodology for broad spectrum antibacterial production. The organism yielded maximum response (22.66±0.894 mm of zone of inhibition against MRSA) in 250 mL Erlenmeyer flask containing 50 mL potato dextrose broth supplemented with (g/L) glucose, 7.53; yeast extract concentration, 0.47; NaCl, 0.10 with medium pH 6.46; after 134 hours of incubation at 26°C. Optimized fermentation parameters enhanced antibacterial activity up-to more than 50% than the pre-optimized one (10.33±0.57 mm). Endophytic LCS1 was also efficient in free radical scavenging tested by DPPH, ABTS, H2O2 and FRAP assay with an IC50 values of 23.38±5.32 to 82.873±6.479 μg/mL.

Toxicity, Antioxidant Activity, and Phytochemicals of Basil (Ocimum basilicum L.) Leaves Cultivated in Southern Punjab, Pakistan.

Basil (Ocimum basilicum L.) is one of the most common aromatic herbs, a rich source of bioactive compounds, and is used extensively to add aroma and flavor to food. The leaves, both in fresh and dried form, are used as a culinary ingredient in different cultures. O. basilicum is also famous for its therapeutic potential and preservation effects. The present study investigated the cytotoxicity of basil at three different growth stages (GS), i.e., GS-1 (58 days of growth), GS-2 (69 days of growth), and GS-3 (93 days of growth) using the brine shrimp lethality assay. The results revealed that cytotoxicity was influenced by GS and the concentration of extracts. Aqueous extracts of basil at a concentration of 10 to 1000 µg/mL did not show notable toxicity. The lowest mortality rate, i.e., 8.9%, was recorded for GS-2 at the highest tested dose of basil extracts. The mortality rate at GS-1, GS-2, and GS-3 was found to be 26.7 ± 3.34%, 8.91 ± 0.10%, and 16.7 ± 0.34%, respectively, at 1000 µg/mL. GS-2 basil powder with the lowest toxicological risk was extracted with different solvents, viz., n-hexane, dichloromethane, ethanol, and water. The highest concentration of plant secondary metabolites including total phenolic acid, flavonoids, and tannin content was observed in ethanol extracts. Ethanol extracts also exhibited the highest antioxidant activity in DPPH, FRAP and H2O2 assays. LC-ESI-MS/MS analysis presented ethanol extracts of basil as a promising source of known health-promoting and therapeutic compounds such as rosmarinic acid, ellagic acid, catechin, liquiritigenin, and umbelliferone. The results suggest basil, a culinary ingredient, as a potential source of bioactive compounds which may offer an array of health promoting and therapeutic properties.

In situ synthesis of Co-doped MoS2 nanosheet for enhanced mimicking peroxidase activity.

To enhance the catalytic activity of two-dimensional layered materials as versatile materials, the modification of transition metal dichalcogenide nanosheets such as MoS2 by doping with heteroatoms has drawn great interests. However, few reports are available on the study of the enzyme-like activity of doped MoS2. In this study, a facile in situ hydrothermal method for the preparation of various ultrathin transition metals (Fe, Cu, Co, Mn, and Ni) doped MoS2 nanosheets has been reported. Through the density functional theory (DFT) and steady-state kinetic analysis, the Co-doped MoS2 nanosheets exhibited the highest peroxidase-like catalytic activity among them. Furthermore, a typical colorimetric assay for H2O2 was presented based on the catalytic oxidation of colorless 3,3′,5,5′-tetramethylbenzidine (TMB) to a blue product (oxTMB) by Co-MoS2. The proposed colorimetric method showed excellent tolerance under extreme conditions and a broad linear range from 0.0005 to 25 mM for H2O2 determination. Concerning the practical application, in situ detection of H2O2 generated from SiHa cells was also fulfilled, fully confirming the great practicability of the proposed method in biosensing fields.Supplementary InformationThe online version contains supplementary material available at 10.1007/s10853-022-07201-z.

Newly Synthesized Thymol Derivative and Its Effect on Colorectal Cancer Cells.

Thymol affects various types of tumor cell lines, including colorectal cancer cells. However, the hydrophobic properties of thymol prevent its wider use. Therefore, new derivatives (acetic acid thymol ester, thymol β-D-glucoside) have been synthesized with respect to hydrophilic properties. The cytotoxic effect of the new derivatives on the colorectal cancer cell lines HT-29 and HCT-116 was assessed via MTT assay. The genotoxic effect was determined by comet assay and micronucleus analysis. ROS production was evaluated using ROS-Glo™ H2O2 Assay. We confirmed that one of the thymol derivatives (acetic acid thymol ester) has the potential to have a cyto/genotoxic effect on colorectal cancer cells, even at much lower (IC50~0.08 μg/mL) concentrations than standard thymol (IC50~60 μg/mL) after 24 h of treatment. On the other side, the genotoxic effect of the second studied derivative—thymol β-D-glucoside was observed at a concentration of about 1000 μg/mL. The antiproliferative effect of studied derivatives of thymol on the colorectal cancer cell lines was found to be both dose- and time-dependent at 100 h. Moreover, thymol derivative-treated cells did not show any significantly increased rate of micronuclei formation. New derivatives of thymol significantly increased ROS production too. The results confirmed that the effect of the derivative on tumor cells depends on its chemical structure, but further detailed research is needed. However, thymol and its derivatives have great potential in the prevention and treatment of colorectal cancer, which remains one of the most common cancers in the world.

Screening of Manilkara zapota (L) P. Royen stem bark ethanolic extract for in vitro \u03b1-glucosidase inhibition, preliminary antidiabetic effects, and improvement of diabetes and its complications in alloxan-induced diabetes in Wistar rats

BackgroundA perusal of the literature suggested that Manilkara zapota (L.) P. Royen stem bark (MZSB) is enriched with several bioactive phytoconstituents but had not been yet screened for its in vitro and in vivo antidiabetic potentials. Thus, the present study aimed to investigate the effects of 70% ethanolic extract of Manilkara zapota (L) P. Royen stem bark (EMZSB) in DPPH- and H2O2-scavenging assay, in vitro α-glucosidase inhibition assay, ameliorating diabetes and its complications in alloxan-induced diabetes in Wistar rats.ResultsWith a maximum extractive yield of 9.16% w/w, EMZSB has shown the presence of various phytochemicals like flavonoids, phenolic compounds, tannins, anthraquinone glycosides, steroids, terpenoids, and alkaloids. EMZSB has elucidated a considerable in vitro free radical scavenging potential by DPPH and H2O2 assays when compared with absolute ethanolic extract of Manilkara zapota (L) P. Royen stem bark (AEMZSB), while ascorbic acid was taken as the standard. Further, EMZSB demonstrated high in vitro α-glucosidase enzyme inhibition potential (IC50 = 119.79 ± 1.52 µg/mL) than AEMZSB (IC50 = 129.92 ± 2.29 µg/mL) with a significant difference (p < 0.01), when acarbose was taken as reference inhibitor (IC50 = 86.43 ± 1.26 µg/mL). During acute toxicity studies EMZSB was safe up to 2000 mg kg−1 doses while, found causing moribund status followed by mortality in mice at 3000 mg kg−1 and above doses. A preliminary antidiabetic study with EMZSB-250 mg kg−1 in normal rats showed no sign of hypoglycemia; however, a dose-dependent antihyperglycemic effects were observed in oral glucose tolerance test in glucose-loaded rats. In vivo assessment with EMZSB-250 mg kg−1 in alloxan-induced rats demonstrated significant blood glucose-lowering effects with perfection in serum lipid profile, body weight enhancement, cardiovascular risk indices, nephroprotective effects, augmentation in liver glycogen content, and histopathological evidence of normal architecture of kidneys with no marks for nephritis.ConclusionsEMZSB-250 showed significant antidiabetic effects and ameliorated diabetic complications by improving glycemic control and accompanying biochemical alteration.

Specifically triggered dissociation based ratiometric electrochemical sensor for H2O2 measurement in food samples

A novel ratiometric strategy based electrochemical sensor was developed to quantitative assay of H2O2 in different food samples. 4-aminophenylboronic acid pinacol ester (ABAPE) dissociation was specifically triggered by H2O2 to generate electro-active 4-aminophenol (4-AP), which not only can be oxidized to indirectly indicate the concentration of H2O2, but also endowed the sensor with high selectivity. Meanwhile, a reference probe of poly(thionine) (TH) was modified with ketjen black (KB) and gold nanoparticles (AuNPs) on electrode surface. KB and AuNPs displayed high electrocatalytic activity to 4-AP. A current ratio between 4-AP and TH (i/iTH) showed a good linear relationship with the concentration of H2O2 in a range of 3.0 × 10−7 – 1.0 × 10−4 mol/L (0.010 ppm − 3.40 ppm) with a limit of detection of 2.6 × 10−7 mol/L (0.009 ppm) (S/N = 3). Moreover, the ratiometric strategy based sensor possessed good accuracy, reliability, and stability, and successfully determined H2O2 in food samples with satisfactory results.

Antioxidant, Antibacterial, and Anti-diabetic Activity of Green Synthesized Copper Nanoparticles of Cocculus hirsutus (Menispermaceae).

The emergence of new technologies has led to the discovery of the biological properties of nanoparticles through green approach. In the present investigation, we report the potential antibacterial, antioxidant, and anti-diabetic properties of copper nanoparticle (CuNPs) synthesized by reducing 3mM copper acetate solution with aqueous leaf extract of Cocculus hirsutus. A colour change from deep brown to dark greenish brown indicated the formation of copper nanoparticles. The so-formed CuNPs were characterized by employing UV spectroscopy, FTIR, SEM, and EDX analyses which described sheet-like structure morphology having typical size of 63.46nm. Later, the synthesized CuNPs efficiency was evaluated against bacterial pathogens, and was found highly toxic to B. subtilis and S. aureus strains. The synthesized CuNPs were examined through H2O2 and PMA assays which demonstrated the highest free radical scavenging activity. Besides, the resulted CuNPs revealed the higher anti-diabetic efficacy in both the [Formula: see text]-amylase and [Formula: see text] -glucosidase inhibition assays (64.5% ± 0.11 and 68.5% ± 0.11, respectively). Finally, our findings report that C. hirsutus can be exploited as a source for green synthesis of CuNPs, having potent in vitro antioxidant, antibacterial, and anti-diabetic properties.

Naked-Eye Detection of Hydrogen Peroxide on Photoluminescent Paper Discs.

We have developed a turn-on photoluminescence protocol to detect hydrogen peroxide (H2O2) utilizing a supramolecular hydrogel as a sensing platform. Hydrogen peroxide is widely used in formulations, starting from healthcare products to explosives. It is also known to induce deleterious health effects at its irregular physiological concentration and considered as a biomarker in various disease conditions. We designed molecule 2, which releases the Tb3+ sensitizer biphenyl-4-carboxylic acid (1) upon unmasking by hydrogen peroxide. This chemistry led us to develop a sensitive photoluminescence assay for H2O2 through the 1-induced photoluminescence of terbium (Tb3+) in a hydrogel matrix. Paper discs (0.45 cm) were coated with the soft hydrogel to make the sensing process simple and cost-effective. The green luminescence from the paper discs, observed under a UV lamp, allowed naked-eye detection of H2O2 in the micromolar level without any sophisticated instrumentation. Image processing software or a plate reader can be used for the accurate quantification of the analyte in micromolar and nanomolar ranges. Several commercial hand sanitizers containing hydrogen peroxide were tested by this method. The results indicated that this low-cost system could be practically adopted, especially in resource-limited areas, to quantify/detect H2O2 for quality control purposes or other applications.

Protection of bovine mammary epithelial cells by a nanoemulsion of the medicinal herb Achyrocline satureioides (Lam.) DC and its capacity of permeation through mammary epithelium.

The low levels of toxicity and cytoprotective effect attributed to Achyrocline satureioides (Lam.) DC, a medicinal plant native to South America, are of interest for bovine mastitis therapy. This research paper reports the hypothesis that a nanoemulsion of macela extract (Achyrocline satureioides) exerts protective effects on bovine mammary alveolar cells -T (MAC-T) and increases the permeation of flavonoid compounds through mammary epithelium. Extract-loaded nanoemulsions (2.5 mg/ml) (NE-ML) (n = 4) were prepared using high-pressure homogenization with varying concentrations of flaxseed oil and Tween 80. Permeation and retention of free and nanoencapsulated quercetin, 3-O-methylquercetin and luteolin were performed on mammary glandular epithelium using Franz diffusion cells. The cell viability was evaluated on mammary epithelial cells (MAC-T lineage) using the MTT method (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) after exposure to loaded and blank nanoemulsions (NE-ML and NE-BL). Necrotic or apoptotic cell death was evaluated by flow cytometry after exposure to nanoemulsions (NE-ML and NE-BL). Subsequently, the cell death was assessed by previously treating MAC-T cells with NE-ML for 23 h, followed by exposure to H2O2 (2 mM) for 1 h. Higher permeation of quercetin and 3-O-methylquercetin in NE-ML was found compared to that of free extract with a final permeated amount of 50.7 ± 3.2 and 111.2 ± 0.6 μg/cm2 compared to 35.0 ± 0.6 and 48.9 ± 1.2, respectively. For NE-BL, the IC50 was at least 1.3% (v/v), while for the NE-ML, it was at least 2.6% (v/v). After exposure to NE-ML (5 and 1.2%, v/v), the percentage of apoptotic cells was reduced (±30%). For the H2O2 assay, the percentage of cells in necrosis was reduced by 40% after exposure to NE-ML1% (v/v) + H2O2 2 mM. The protective effects and increased permeation of macela nanoemulsion make this a promising new candidate for bovine mastitis therapy.

Biological synthesis and characterization of Passiflora subpeltata Ortega aqueous leaf extract in silver nanoparticles and their evaluation of antibacterial, antioxidant, anti-cancer and larvicidal activities

Passiflora subpeltata contain rich source of secondary metabolites and its plant materials mostly used for cancer and mosquito related problem. Therefore, in this study, green synthesis of silver nanoparticles using Passiflora subpeltata of aqueous extract (Ps-AgNPs) as reducing and stabilizing agent. The UV–Visible spectra of Ps-AgNPs showed absorption peak at 456 nm and formation of AgNPs. XRD pattern showed the crystalline nature and SEM images displayed predominantly spherical shape of NPs. FT-IR analysis exhibition capping of AgNPs by bioactive compounds from Ps-AgNPs. Antibacterial activity in PS-AgNPs shown good activity with best of B. cereus (27 mm) at higher dose of 75 μg/mL. Antioxidant activity was tested against DPPH, ABTS and H2O2 assays and the best scavenging assay were observed in DPPH with IC50 value of 108.92 μg/mL. The anti-proliferative activity in human colon cancer cell-line (HT-29) indicates that the significant result with IC50 value of 33.05 μg/mL. Larvicidal activity of PS-AgNPs showed good activity against Cx. quinquefasicatus larvae (LC50-4.99 units and LC90-22.19units). The green synthesized NPs could be potential activity and it used in different biomedical application.

The effect of Kappaphycus alvarezii active fraction on oxidative stress and inflammation in streptozotocin and nicotinamide-induced diabetic rats

BackgroundHigh glucose concentration increases the glycation process which leads to oxidative stress and inflammation, that can cause complications in diabetes. Several medicinal plants have been used in the treatment of diabetes and its complications. One of them is Kappaphycus alvarezii, an algae that has known antidiabetic abilities. This study aimed to examine the effect of K. alvarezii active fraction on plasma hydrogen peroxide (H2O2) and Tumor Necrosis Factor α (TNFα) levels, renal NADPH oxidase 4 (NOX4) and Nuclear Factor κ B (NFκB) gene expressions.MethodsActive fraction was obtained from bioassay-guided fractionation with antiglycation ability. In vivo study was performed on twenty Wistar male rats. The level of H2O2 was measured using H2O2 Assay Kit, the Optical Density value measured using spectrophotometer at a wavelength of 405 nm. Plasma TNFα level was measured using ELISA. Renal NOX4 and NFκB gene expression was analyzed using qPCR.ResultsActive fraction significantly reduced plasma H2O2 but not TNFα levels. Furthermore, renal NOX4 gene expression was lower in the diabetic rat group treated with active fraction compared to the untreated group but not NFκB gene expression.ConclusionsK. alvarezii active fraction has an activity to reduce plasma H2O2 as well as renal NOX4 gene expression. Therefore, this fraction could be developed as a potential candidate for diabetes treatment through oxidative stress mechanisms.

Antioxidant property of beta-cryptoxanthin produced by Kocuria marina DAGII

Beta-cryptoxanthin (β-CRX), a pro vitamin A carotenoid was extracted from Kocuria marina DAGII, a gram positive bacteria isolated from soil. To determine the antioxidant activity of β-CRX against free radicals, DPPH, ABTS, H2O2 and TAC assay were performed. The scavenging results showed antioxidant activity of beta-cryptoxanthin. The scavenging activity increased with increased pigment concentration. The IC50 value of beta-cryptoxanthin for DPPH, ABTS and H2O2 were found to be 32.51 ± 1.15 µg/ml, 41.91 ± 0.33 µg/ml and 38.30 ± 1.13 µg/ml respectively. The TAC assay value of beta cryptoxanthin was 872.0101 ± 1.84 µg BHT/mg of sample. This showed that beta-cryptoxanthin extracted from K.marina DAGII cells can serve as economical pigment with antioxidant property.

Molecular Docking, ADME Studies, Synthesis, and Anti-oxidant Activity of Novel Quinazoline-4(3H)-one Derivatives

Background Free radicals are linked to numerous human diseases. Free radicals can be neutralised by antioxidants thereby reducing their negative effects. We sought to learn more about the antioxidant and free radical scavenging abilities of quinazoline derivatives in this study.Aim of the study Drug discovery and development is a time-consuming interdisciplinary and expensive process. Advances in computational procedures have empowered in silico routines and specifically structure-based drug design technique to accelerate new target choice for the improvement of lead compounds. Hence the present work aimed to identify the potent quinazolinone compounds for synthesis.Methodology The synthesis was carried out from the reaction of anthranilic acid and primary aromatic amines with Vilsmeier reagent DMFPOCl3 . Five derivatives which obeyed rule of five having desired physio-chemical properties were synthesized PDB code 6DE4. The reaction occurred in few minutes under microwave irradiation providing good yields. The synthesized compounds were isolated recrystallised by using suitable solvents purified by Thin Layer Chromatography TLC and characterized by Fourier-transform infrared spectroscopy FT-IR Proton-Nuclear Magnetic Resonance 1 H NMR and mass spectroscopy.Results All the synthesized compounds 3a 4a 8b 9b 10b were evaluated for their anti-oxidant activities by 22-diphenyl-1-picrylhydrazyl DPPH Hydrogen peroxide H2 O2 assays. All of them showed significant anti-antioxidant activity with 8b exhibiting the maximum activity compared to others.Conclusion On comparison with standard ascorbic acid quinazolinone derivatives were found to possess effective in vitro antioxidant activity. These quinazoline analogues could be considered as useful templates for further development to obtain more potent antioxidant activity.nbsp

Cationic AIEgen micelle-improved chemiluminescent H2O2 assay by integrating reactant approach and CRET.

The enhancement of chemiluminescence (CL) intensity is significant in the development of chemiluminescent detection systems with improved sensitivity. In this study, a cationic surfactant with an intrinsic aggregation-induced emission emitter (AIEgen) has been applied to boost the CL signal of the horseradish peroxidase-luminol-H2O2 system. The formed cationic AIEgen micelles enhance the CL signal in two ways: the electrostatic attraction-mediated enrichment and approach of reactants and the high CRET efficiency between excited luminol radicals and AIEgen in the surfactant backbone. As a result, strong CL intensity is produced. Rapid and sensitive H2O2 detection is realized through the proposed cationic AIEgen micelle-containing chemiluminescent system with a limit of detection of 100 nM. The favourable selectivity over other possible interferents including metal ions and anions is due to the specific chemical reaction. Practical H2O2 analysis of thawing water samples with high accuracy using the proposed chemiluminescent platform is realized and is consistent with standard methods.

Comparative Study of Antioxidant Activities of Selected Medicinal Plants of Shujabad Area in Multan, Pakistan

Background: In humans, especially in elderly patients, free radicals and oxidative stress are one of the main reasons behind a number of diseases/disorders, such as cardiovascular, pulmonary and neuronal in nature. Therefore, it is imperative to investigate substances/compounds that possess potent free radical scavenging activity, especially, from the indigenous flora. Methods: The present study was aimed to screen the free radical scavenging activity of ethanolic and methanolic leaf extracts of three medicinal plants: Syzygium cumini, Psidium guajava and Callicarpa dichotoma. The antioxidant activity was determined using 1,1-Diphenyl-2-picryl hydroxyl (DPPH) and Hydrogen peroxide (H2O2) scavenging assays. Various concentrations (250, 500, 750 and 1000μg/ml) of plant extract were used to carry out the assays and Ascorbic acid was used as the standard. The free radical quenching potential was expressed in inhibition percentage (%) and concentrations were expressed in μg/ml. Optical density of DPPH and H2O2 was measured using spectrophotometer at 517 and 230 nm, respectively. Results: Results from the DPPH and H2O2 assays showed that antioxidant activities were observed to be highest in P. guajava (89 and 81% respectively) followed by S. cumini (84 and 72% respectively) and C. dichotoma (83 and 70% respectively) in the ethanolic extracts. Conclusion: It is concluded that the selected plant materials used for the study have a powerful antioxidant potential and could be used in various therapeutic and medicinal applications.

In vitro studies on anti-inflammatory, antioxidant and antihyperglycemic activities of potential probiotic Pediococcus acidilactici NCDC 252

Probiotics are live microbes which positively influence the health when consumed in adequate amount. Lactic acid bacteria (LAB) are commonly used probiotics and are generally found in yogurt and fermented foods. They provide barrier for pathogens by secreting peptides and other metabolites. Pediococcus acidilactici NCDC 252 is a LAB of dairy origin with probiotic attributes. NCDC 252 was studied for in vitro anti-inflammatory, antioxidant and antihyperglycemic activities. Anti-inflammatory activity was studied by human red blood cell (HRBC) membrane stabilization method, protein (albumin) denaturation inhibitory activity and heat induced haemolysis. Antioxidant activity was evaluated by α, α-diphenyl-β- picrylhydrazyl (DPPH) radical and hydrogen peroxide (H2O2) scavenging assays. Alpha amylase inhibition assay was performed to examine antihyperglycemic effect. NCDC 252 exhibited potent anti-inflammatory but moderate antioxidant and antihyperglycemic activities as compared to control. NCDC 252 exhibited 65%, 70% and 49% membrane stabilization, protein denaturation and heat induced activity respectively. Scavenging effect was 45 % and 60% in H2O2 and DPPH assays respectively. Alpha amylase inhibition was 48 %. These results suggest therapeutic potential of NCDC 252 and open new avenues to treat disorders related to free radical generation such as inflammation and diabetes mellitus after in vivo evaluation of NCDC 252 to confirm its efficacy in animals.

FeS nanoparticles embedded in 2D carbon nanosheets as novel nanozymes with peroxidase-like activity for colorimetric and fluorescence assay of H2O2 and antioxidant capacity

Nanozymes with high catalytic performance play a vital role in the construction of advanced biosensors for the signal detection and analysis of complicated biological samples. Herein, FeS nanoparticles (NPs) embedded in 2D carbon nanosheets (denoted as FeS@CNs) are demonstrated to serve as excellent nanozymes with high catalytic activity. Notably, the introduction of mesoporous carbon substrate could effectively improve the enzymatic peroxidase-like catalytic ability of embedded FeS nanozymes, especially in the fluorescence catalytic system. Based on the high peroxidase-like activity of proposed FeS@CNs nanozymes, a facile method was then designed for H2O2 assay with detection limit as low as 0.78 μM and 0.86 μM for the colorimetric and fluorescence method, respectively. The oxidation of the colorimetric and fluorescence substrates could be ascribed to the hydroxyl radical (·OH) produced by catalytic reaction of H2O2 with FeS@CNs nanozymes. Thus, the FeS@CNs nanozymes-based H2O2 sensing platform was further constructed to evaluate the antioxidant capacity of glutathione (GSH), cysteine (Cys), and gallic acid (GA). Notably, FeS@CNs nanozymes can keep the functionality in a broad pH range (2.0 ~ 9.0) for catalytic reaction, delivering a great potential in the fabrication of advanced biosensors.

Recent Reports of Plants as DNA Protection Agents

Background:DNA damage induced by reactive oxygen species (ROS) leads to cell death, tissue damage and may contribute towards the onset of several chronic diseases.Objective:Plants carry a cocktail of compounds like flavonoids, polyphenolics, tannins, saponins, terpenoids, and alkaloids that have shown promising pharmacological potential in treating various illnesses responsible for high mortality. Some of the plant-derived compounds carry the potential to shield the DNA from damage induced by reactive oxygen species (ROS). The objective of this article is to present recent reports of plant extracts and natural products as DNA protecting agents in one place.Methods:This review summarizes the plant-based extracts and isolated compounds with promising DNA protection activities against ROS induced damage. The antioxidant potential of plants is assessed using various antioxidant assays like DPPH assay, FRAP assay, and H2O2assay. Further, the DNA protection of the extract is validated by using a plasmid protection assay. The mechanism of protection generally involves the scavenging of ROS by the antioxidants present in plant extracts.Results and Conclusion:This review summarizes the work done on plant-based compounds for their antioxidant and DNA protection abilities invitro. However, in vivo evaluation of promising plants is the need of time.

6-Gingerol and Semisynthetic 6-Gingerdione Counteract Oxidative Stress Induced by ROS in Zebrafish.

6-Gingerol (1) is one of the major components in ginger and developing new synthetic methodologies could bring semisynthetic analogs with improved therapeutic properties. Towards this, multigram scale isolation of 6-gingerol with excellent purity was optimized using a simple and robust extraction, followed by column purification. Synthesis of 6-gingerdione, 7 from 6-gingerol was then achieved through selective -OTBDMS protection, DMP oxidation and deprotection reaction sequence for the first time. Compounds 1, 7 and 8 (dehydrozingerone) exhibited excellent cell-free antioxidant properties in DPPH, ABTS, superoxide radical scavenging assay and H2 O2 assay at 10-50 μM concentrations. The hemolytic study suggests that up to 50 μM, all three compounds did not exhibit toxicity to human erythrocytes. When H2 O2 treated zebrafish larvae groups (96hpf) were exposed to compounds 1, 7 and 8, it increases the SOD (19, 19.1 and 18.7 U/mg protein), CAT (18.1, 16.5, and 15.8 μmol/mg levels and decreases the lipid peroxidation level (13, 15 and 18 nmol/mg protein), respectively. In vivo ROS levels and degree of cell death were studied using DCFDA and Acridine orange assays. Compounds 1, 7 and 8 decreases the ROS and cell death level significantly. Taken together, compounds 1, 7 and 8 exhibit excellent antioxidant properties, counteract H2 O2 induced oxidative stress, reduces cell death in zebrafish larvae.