Peroxide Scavenging Activity Research Articles

Phytochemical estimation and evaluation of antioxidant activity of hydro-alcoholic and ethylacetate extracts of Tribulus terrestris linn. (gokhru) and Solanum nigrum linn (makoi)

Tribulus terrestris L. and Solanum nigrum L. has been used traditionally since ages. To explore the phytoconstituents (qualitatively and quantitatively) and estimate antioxidant activity of hydroalcoholic and ethyl acetate extracts of fruits of Tribulus terrestris L. and Solanum nigrum. Different methods were adopted for phytochemical screening. Evaluation of antioxidant potential was achieved by total anti-oxidant capacity assay, hydrogen peroxide scavenging activity, DPPH radical-scavenging activity, Nitric oxide radical scavenging activity and reducing power assay. The qualitative estimation of fruits of Tribulus terrestris L and of Solanum nigrum L. showed the presence of various phytoconstituents likewise tannins, saponins, flavonoids and terpenoids. Quantitative estimation revealed the presence of flavonoids (5.01%w/w), saponins (0.70%w/w), and terpenoids (0.013%w/w) in fruits of Tribulus terrestris L. whereas presence of flavonoids (10.46%w/w), saponins (11.02%w/w) and terpenoids (0.034%w/w) was found in fruits of Solanum nigrum L. It can be concluded that both the extracts of Tribulus terrestris L and Solanum nigrum L possess significant antioxidant activity.

Comparative evaluation of in vitro antioxidant potential of Punica granatum L. leaves extracts

A comparative evaluation of tannins, flavonoid, phenol quantification and antioxidant potential of aqueous, methanol, n-hexane, acetone and chloroform extracts of Punica granatum leaves were determined. Quantification of phenolic was carried out by the technique of Folin-Ciocalteau, using rutin as standard flavonoids were evaluated through the technique of colorimetry, tannin was measured by the difference of total phenolics and free phenolics assay procedure. Antioxidant activities were evaluated by four standards antioxidant techniques including Superoxide dismutase (SOD)-like activity, Hydrogen Peroxide (H2O2) scavenging activity,1, 1’-diphynyl- 2-picrylhydrazyl (DPPH) activity and Nitric oxide (NO) scavenging activity method using ascorbic acid as standard. The antioxidant activities showed that methanol extract at 500μg/mL calculated maximum DPPH inhibition activity was 78±1%, H2O2 scavenging activity was 90±0%, SOD-like activity was 88±0% and NO scavenging activity was 90±0%. The outcomes indicated the major antioxidant actions were carried out by the extract of methanol; the entire potential was increased in the directive of methanol> chloroform> acetone>aqueous>n-hexane extracts. The results indicate that Punica granatum leaves extracts to have potent antioxidant activities that would have beneficial effects on human health and methanol extracts are superior with better antioxidant potential. The leaves extracts of Punica granatum could be of enormousattention in the enhancement of top value-added secondary products and the appliance of functional and green substitutes in thecosmetics, food and pharma industries.

PROXIMATE AND QUALITATIVE PHYTOCHEMICALS STUDIES ON LEAVES AND STEMS OF Adansonia digitata L

The attractive colours and fragrances produced by the plants are due to specific phytochemicals present in them. The objective of this study was to find out some physio-chemical parameters of leaves and stems of plants, and the presence of phytochemicals, carbohydrate, proteins, and antioxidant activity by hydrogen peroxides scavenging assay in the ethanolic and hydroethanolic extract of Adansonia digitata in both leaves and stems by qualitative screening method. In qualitative analysis, the presence of phytochemicals compounds such as alkaloids, saponins, tanins, phenols, anthraquinoes, flavonoids, steroids, terpinoids were determined in the ethanolic and hydroethanolic extract by standard methods. Results concluded that the presence of this active compound may be responsible for the medicinal exploitation of the plant. The hydrogen peroxide scavenging activity significantly increases with concentration. The phenolic and vitamin C content in the baobab leaf fraction played a significant role in the antioxidant activity due to reducing mechanisms.

PHYTOCHEMICAL AND PHARMACOLOGICAL ACTIVITIES OF MUKIA MADERASPATANA

Objective: The study aimed to evaluate the bioactive compounds of Mukia maderaspatana and its properties. In addition, the preliminary phytochemical analysis and antioxidant potential of Mukia maderaspatana were performed. Methods: Extraction of leaves of Mukia maderaspatana made using Soxhlet apparatus, followed by evaluation of phytochemicals such as alkaloids, flavonoids, coumarin, glycosides, terpenoids, tannin, steroid, saponin, phenol, anthraquinone by the standard methodology of Sofowara, Trease and Evans, Harborne. Quantification of phytochemicals were performed accordingly to standard methodology. Antioxidant activity were performed accordingly to methodology of Shimada, Prieto, Zhang and Benzie. Methodology of Hema et al. is followed for detection of bioactive compounds by GC-MS analysis. Results: The Qualitative analysis revealed the presence of higher concentration of phytocompounds in Hydroalcoholic extract. The yield of alkaloid (215.8±4.78 mg AE), flavonoid (307.10±8.73 mg QE), phenol (374.50±6.41 mg GAE), tannin (129.98±5.32 mg TAE) and terpenoids (119.23±4.17 mg LE) are higher in hydroalcoholic extract than aqueous and methanolic extract. IC50 value for DPPH radical scavenging activity, Total antioxidant activity, Hydrogen peroxide scavenging activity and Ferric reducing antioxidant power activity are (61.43µg/ml), (59.68µg/ml), (55.69µg/ml), (64.60µg/ml). GC-MS analysis revealed the presence of about thirty compounds in hydroalcoholic extract of Mukia maderaspatana. Conclusion: The present study reveals that Mukia maderaspatana is an important medicinal plant. We can conclude that Leaves of Mukia maderaspatana are good source of antioxidants, which might cure the disease related to oxidative stress.

Physicochemical, phytochemical and antioxidant efficacy of the medicinal plant Coccinia Grandis

India contains seven thousand plant species. Plants are important for human health. (Coccinia grandis) is an edible food crop. (Coccinia grandis) (methanolic extract) alkaloids, flavonoids, cardiac glycosides, terpenoids, phenolics, proteins, carbohydrates, steroids and coumarins (phytochemical assay, physiochemical assay). Estimates were made using standard algorithms. The soxhlet extraction was used to extract the different extracts. This study reveals the presence of different types of phytochemicals, physicochemicals and antioxidants. (Coccinia grandis). The leaves of this plant contain excellent antioxidants. Methanolic and Ethanolic extract were used (plant leaf) for the Antioxidant assays (DPTH, Hydrogen peroxide scavenging activity, FRAP assay and Total Antioxidant capacity assay ). Antioxidants are very important, especially when getting rid of disease. (Louis 1989). Plant phytochemicals have protective functions (immunization). (Coccinia grandis). Extracts made from plant materials. It contains phenolics. It destroys the antioxidant breakdown of lipids. This increases the nutritional value of the food and the quality of the food. This study was done to reveal the medicinal properties and value of medicinal plants. Our study is important for foundation research and future pharmaceutical research.

추출 조건에 따른 제주산 레드비트(Beta vulgaris L.) 색소의 항산화 활성 비교

Purpose: This study evaluates the antioxidant activities of natural pigment extracted from Jeju red beet under different extraction conditions. Methods: Betacyanin and total phenolic contents of red beet pigment extracted with varying concentrations of beet powder (2.5, 3.75, 5.0%), extraction temperature (30, 40, 50℃), and extraction time (6, 9, 12 hr) were analyzed. Additionally, in vitro antioxidant activities were measured, including DPPH free radical scavenging activity, ABTS⁺ radical scavenging activity, hydrogen peroxide scavenging activity, and the reducing power of the extracted pigment. Results: After extraction, the red beet pigment contained 0.51-4.12 mg/g betacyanin and 29.87-32.82 mg GAE/g total phenolics. The highest betacyanin content was obtained when extracted with the beet powder concentration of 2.5% to water at 30℃ for 6 hr. The DPPH and ABTS⁺ radical scavenging activities of the extract revealed proportionally higher antioxidant activities with higher total phenolic contents. Conclusion: These results indicate that red beet extract can be used in the food industry as a natural food colorant having antioxidative activity.

Antioxidant and cytoprotective properties of seeds and seed by-products from lotus (Nelumbo nucifera)

The seed of Nelumbo nucifera Gaertn., commonly known as Chinese lotus, has been used as an indigenous medicine in Taiwan. The present study aims to evaluate the variable antioxidant activity of Nelumbo nucifera ethanolic extracts (NNEE) collected from different parts of the lotus. The seed epicarp had significantly higher extractable total phenolic content (TPC) and flavonoid content (TFC) than the seed and seed pod. Compared to the seed and seed pod, the seed epicarp also exhibited lower IC50 values of 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid (ABTS), EC50 for reducing power, and hydrogen peroxide (H2O2) scavenging activity. Moreover, DPPH and ABTS radicals, reducing power activity, and H2O2 scavenging activity by NNEE were highly and significantly associated with TPC and TFC. Seed epicarp NNEE at a concentration of 25 μg/mL gave significantly higher protection to Raw 264.7 mouse macrophages against H2O2 induced damage compared with blanks. Seed epicarp NNEE was also found to have the most significant protection effect on oxidative DNA damage. Therefore, the NNEE of seed epicarp exhibited higher in vitro and ex vivo antioxidant activity, and can be used as a functional ingredient representing a potential source of natural antioxidants to prevent and treat oxidative stress-related disorders.

Synergistic Effect of Conventional Medicinal Herbs against Different Pharmacological Activity.

Triticum aestivum (Family: Poaceae), Ocimum sanctum (Family: Lamiaceae), and Tinospora cordifolia (Family: Menispermaceae) are commonly known as wheatgrass, tulsi, and giloy, respectively, which are the plants used as medicines for the treatment of various diseases. All three medicinal plants possess phenolic compounds with other important chemical constituents such as polysaccharides, aliphatic compounds, and alkaloids. The extract of these plants has been prepared and investigated for antioxidant, total phenolic content, total flavonoid content, and antimicrobial study in order to discover potential sources for new pharmaceutical formulations. To determine the antioxidant activity, a free radical scavenging assay for 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydrogen peroxide was performed using ascorbic acid as the standard. The R2 value of the prepared extract was found to be 0.9964 and 0.990 in DPPH and hydrogen peroxide scavenging activity, respectively. The phenolic and flavonoid content was found to be 87.50 μl/ml and 58.00 μl/ml, respectively. The diffusion method was used to screen the antimicrobial activity of the prepared extract sample against various microorganisms. This extract showed better results for antioxidant and antimicrobial activity.

In Vitro Antioxidant and Prooxidant Activities of Red Raspberry (Rubus idaeus L.) Stem Extracts.

Leaves and stems of red raspberry (Rubus idaeus) are used in Lithuanian folk medicine. Healing properties of raspberry are related to the content of bioactive compounds, mainly polyphenols. Extracts of raspberry leaves contained higher total phenolic content (TPC) (1290 mg/L, expressed in gallic acid equivalent) compared to that in extracts of stems or peeled bark (up to 420 mg/L and 598 mg/L, respectively). To find out whether the collection time of herbal material was critical for the properties of the extracts, the stems were collected at different times of the year. TPC in the extracts depended more on extraction conditions rather than on the sampling time. Antioxidant activity of raspberry stem and bark extracts tested by spectrophotometric (DPPH● scavenging) and electrochemical (cyclic and differential pulse voltammetry) assays correlated with TPC. DPPH radical scavenging activity values for stem, leaf, and bark extracts were as follows: ≤1.18 ± 0.07, 1.63 ± 0.10, and ≤1.90 ± 0.04 (mmol/L, TROLOX equivalent), respectively. Assessed electrochemically, hydrogen peroxide-scavenging activity of extracts was independent on TPC. The latter activity was related to the presence of some protein in the extract as revealed by gel electrophoresis. Prooxidant activity of raspberry stem extracts was dependent on solution pH and temperature.

Antioxidant interactions among hydrophilic and lipophilic dietary phytochemicals based on inhibition of low-density lipoprotein and DNA damage.

Antioxidant interaction among hydrophilic phytochemicals (caffeic acid, p-coumaric acid) and lipophilic phytochemicals (β-carotene, lycopene) in different mole ratios (n/n, 1:9, 3:7, 5:5, 7:3, 9:1) was evaluated. Assays performed were based on the scavenging activity of hydrogen peroxide (H2 O2 ), the inhibition of low-density lipoprotein oxidation (ox-LDL) and DNA damage in vitro, using isobological analysis, synergistic rate (SR), and combination index (CI). Results showed that groups containing higher ratios of hydrophilic phytochemicals exhibited synergism while those containing higher ratios of lipophilic phytochemicals showed antagonism. Meanwhile, groups containing caffeic acid (e.g., caffeic acid:β-carotene, 9:1) with more hydroxyl groups showed higher synergism (SR=0.76 ± 0.02, CI=0.77 ± 0.03) than groups containing p-coumaric acid (e.g., p-coumaric acid:β-carotene, 9:1, SR=0.88 ± 0.04, CI=0.82 ± 0.05) on the scavenging activity of H2 O2 . Groups that contained lycopene (caffeic acid: lycopene, 9:1) with a higher ability of regeneration by phenolic acids showed more significant synergism (SR=0.70 ± 0.02, CI=0.79 ± 0.03) than groups containing β-carotene (e.g., caffeic acid:β-carotene, 9:1, SR=1.00 ± 0.03, CI=0.98 ± 0.04) on the inhibition of DNA damage. This study provided a basis for antioxidant interactions among phytochemicals against ox-LDL and DNA damage in vivo. In addition, the choice of appropriate ratios and structures of hydrophilic and lipophilic phytochemicals should be considered in the diet and formulation of functional foods.

Subcritical Water Enhanced with Deep Eutectic Solvent for Extracting Polysaccharides from Lentinus edodes and Their Antioxidant Activities.

In the present study, subcritical water extraction (SWE) assisted with deep eutectic solvent (DES) is used to extract Lentinus edodes polysaccharides (LEP). In addition, the antioxidant activity of the polysaccharide samples was also investigated. Based on a single factor test and response surface test, the optimal extraction factors were a liquid–solid solvent of 40:1 mL/g, extraction temperature of 147.23 °C, water content of 39.76% and extraction time of 17.58 min. Under these extraction conditions, the yield of LEP was 6.26 ± 0.08%. Compared with the SWE and hot water extraction (HWE), it improved by 19.24% and 17.01%, respectively. In addition, the results of monosaccharide composition, molecular weight, FT-IR, UV and SEM confirmed that the extracts had the features of polysaccharides. Interestingly, the polysaccharides obtained with the SWE assisted with the DES procedure showed a higher DPPH scavenging activity, hydroxyl radical scavenging activity and hydrogen peroxide scavenging activity, which indicated that the polysaccharides with this method had a stronger antioxidant activity. These findings demonstrated that the SWE-assisted DES is a strong method to obtain polysaccharides from Lentinus edodes for food, biopharmaceutical and other industrial production.

Physicochemical Properties, Antioxidant and Antimicrobial Activities of Unripe Green and Ripened Yellow Banana (Musa sp.) Peel and Pulp Oil Extracts

Background: Banana peel (Musa Sp.) is more nutritional and rich in phytochemical compounds than its pulp. All parts of the banana plant have medicinal applications. Damage from free radicals at the cellular level causes cell inflammation, increasing the risk of damage from sunlight, radiation, and related development of skin cancer. Objective: The purpose of this study was to assess the physicochemical properties, antioxidant, and antimicrobial activities of unripe green and yellow ripened banana fruit peels and pulp oil extracts. Methods: The oil extraction was done in Soxhelt apparatus using petroleum ether as a solvent. Then, the oil extracts were assessed based on the determination of oil yield, acid value, percent free fatty acid, peroxide value, and free radical scavenging activity using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and hydrogen peroxide, and ascorbic acid. The antioxidant and antimicrobial activities were determined based on ascorbic acid content, DPPH and hydrogen peroxide scavenging activities. The antimicrobial experiment was arranged in completely randomized factorial design with three replications. Results: The result indicated that significantly the highest oil yield (2.60±0.21%), acid value (2.66±0.20%), and free fatty acids (1.34±0.10%) were recorded for green peel oil extract. Significantly, the highest DPPH radical scavenging activity was recorded for green peel (5.85%) followed by green pulp (4.80) and the least for yellow peel (4.50). Ascorbic acid and hydrogen peroxide scavenging activity were significantly higher for yellow peel and green pulp oil extract extracts than for green peel oil extract. The strongest antibacterial activity with the maximum zone of inhibition (15.5mm), minimum inhibitory concentration (0.125μg/ml), and corresponding minimum bactericidal concentration (0.25 μg/ml) was recorded for ripened peel oil extract against Staphylococcus aureus. The antifungal activity of the oil extract presented the highest zone of inhibition (15.67mm), minimum inhibitory concentration (0.125 μg/ml) and corresponding minimum fungicidal concentration (0.25 μg/ml) were recorded for unripe green banana fruit pulp oil extract against Aspergillus versicolor. Conclusion: The result indicated that the banana fruit peel oil extracts demonstrated differential antioxidant and antimicrobial potentials. Thus, the banana peel waste oil extracts proved to have potential sustainable applications in nutritional and drug development technologies.

Juvenile heat stress tolerance in Triticum durum-Aegilops tauschii derived synthetics: a way forward for wheat improvement.

Exponentially increasing population and everchanging climatic conditions are two major concerns for global food security. Early sowing in the second fortnight of October is an emerging trend with farmers in Indo Gangetic Plains to avoid yield losses from terminal heat stress. This also benefits the use of residual soil moisture of rice crop, conserving about one irrigation. But most of the available wheat cultivars are not well adapted to early-season sowing. Two in-house developed SHWs, syn14128 and syn14170, were screened for juvenile heat stress. Seedling length, biochemical parameters, and expression of amylase gene immediately after heat shock (HS) of 45°C for 12h and 20h, and 24h indicated significantly lower malondialdehyde, hydrogen peroxide, and higher free radical scavenging activities. Syn14170 reported higher total soluble sugar (TSS) under both HS periods, while syn14128 had a sustainable TSS content and amylase activity under HS as well as the recovery period. Both the SHWs had lower oxidative damage along with high free radical scavenging under heat stress. The higher expression of amy4 along with sustainable TSS after heat stress in syn14128 indicated it as a potential source of juvenile heat stress tolerance. Variable response of SHWs to different biochemical parameters under heat stress opens future perspectives to explore the enzymatic pathways underlying these responses.

Synthesis and Evaluation of Anticancer activity of some new 3(2h)-one pyridazinone derivatives by Molecular Docking Studies

The present research aims to synthesize new series of 3(2h)-one pyridazinone derivatives with a potential anti-oxidant activity. All the compounds were synthesized by the esterification reaction of 2-(4- Fluoro Phenyl)--butyric acid with sulphuric acid and ethanol followed by hydrazine hydrate to give substituted hydrazides and then hydrazone with substituted ketons, which are cyclized with aldehyde substitutes to give the [5-(2,5-Dichloro-phenyl)-2-oxo-3,4-dihydro-2H-pyridin-1-yl]-acetic acid(4-4chloro-benzylidene)-hydrazide derivatives. Structure of all derivatives was confirmed by Fourier transform infrared spectroscopy (FT-IR) and Nuclear magnetic resonance (NMR) spectroscopy. All these compounds were demonstrated for in-vitro anti oxidant activity by using DPPH radical scavenging activity and hydrogen peroxide scavenging activity. Molecular Docking was carried out by cyclin dependent kinase protein and DNA-hexamer ATGCAT. Molecular docking studies of derivatives were carried out by AutoDock Vina molecular docking software. All the results were calculated by PaDEL software. Results of antioxidant activity revealed that all compounds are potent antioxidants at a concentration of 50µg/ml.

Wound Healing and Antioxidant Capabilities of Zizyphus mauritiana Fruits: In-Vitro, In-Vivo, and Molecular Modeling Study.

LC-HRMS-assisted chemical profiling of Zizyphus mauritiana fruit extract (ZFE) led to the dereplication of 28 metabolites. Furthermore, wound healing activity of ZFE in 24 adult male New Zealand Dutch strain albino rabbits was investigated in-vivo supported by histopathological investigation. Additionally, the molecular mechanism was studied through different in-vitro investigations as well as, studying both relative gene expression and relative protein expression patterns. Moreover, the antioxidant activity of ZFE extract was examined using two in-vitro assays including hydrogen peroxide and superoxide radical scavenging activities that showed promising antioxidant potential. Topical application of the extract on excision wounds showed a significant increase in the wound healing rate (p < 0.001) in comparison to the untreated and MEBO®-treated groups, enhancing TGF-β1, VEGF, Type I collagen expression, and suppressing inflammatory markers (TNF-α and IL-1β). Moreover, an in silico molecular docking against TNFα, TGFBR1, and IL-1β showed that some of the molecules identified in ZFE can bind to the three wound-healing related protein actives sites. Additionally, PASS computational calculation of antioxidant activity revealed potential activity of three phenolic compounds (Pa score > 0.5). Consequently, ZFE may be a potential alternative medication helping wound healing owing to its antioxidant and anti-inflammatory activities.

Effects of Methanol Extract on Bioactive Property and in Vitro Antioxidant Activity of Palma Christi (Anthocleista nobilis G. Don.) Root

Background: Plants have diverse phytochemicals with different solubility levels and medicinal efficacy. This study aimed to determine the presence of phytochemical constituents and in vitro antioxidant activity of methanol root extract of Anthocleista nobilis.&#x0D; Objectives: Determining the bioactive principles and free radical scavenging properties of A. nobilis root&#x0D; Methods: The preliminary phytochemical investigations were performed using standard analytical procedures. The in vitro antioxidant properties were assessed by 2,2-diphenyl-1- picrylhydrazyl (DPPH) free radical scavenging assay, nitric oxide (NO) scavenging activity, ferric reducing antioxidant power (FRAP) assay, total antioxidant capacity (TAC), and hydrogen peroxide (H2 O2 ) scavenging activity.&#x0D; Results: The phytochemical analyses revealed the presence of several compounds: saponins, reducing sugar, alkaloids, tannins, flavonoids, cardiac glycosides, and mucilages. The concentrations of these compounds were different. A considerable quantity of phytochemicals was found in the methanol extract. The impact of the extract on DPPH, NO, FRAP, TAC, H2 O2 radicals were dependently and ascendingly concentrated. Solvent extract demonstrated better antioxidant activity, with DPPH and NO showing maximum antioxidant capability in conjunction with IC50 values of 5.45 µg/mL.&#x0D; Conclusion: The study results prove that A. nobilis is a possible source of natural antioxidants, justifying its use in indigenous medicine.

Antioxidant Activity of TEMON (Clitoria ternatea and Citrus sp.) as an Infused Herbal Tea

Many people around the world believed that herbal tea had a lot of antioxidants contained in it, thus it was widely drunk all over the world. However, the antioxidant capacities of herbal tea may be various because it is affected by the usage of different plants as its primary ingredient. As a result, this study examines the antioxidant activity of herbal tea made from dried Citrus sp. and Clitoria ternatea flower petals. The antioxidant potential was assessed by performing a DPPH and H2O2 scavenging activity assay on 2,2-diphenyl-1picrylhydrazyl (DPPH) and hydrogen peroxide (H2O2) scavenging activity assay, total phenolic, and flavonoid content assay, ABTS reduction, and FRAP assay. This study showed that pure telang (Clitoria ternatea) herbal tea has antioxidant properties. Dried Telang (Clitoria ternatea) tea had the highest activity of antioxidants as we refer to the results of it had the highest activity value in DPPH, ABTS, and FRAP assay and also had the lowest IC-50 value. Followed by TEMON infusion which showed the second-highest antioxidant activity after pure telang infusion. The decrease in antioxidant activity in the mixture of telang and lemon was due to the mixture of lemons which tended to have the lowest antioxidant activity among the three types of infusions tested. The addition of dried lemon has the aim of enhancing the flavor of the tea infusion.

A study on the free radical scavenging and anti oxidant activity of &lt;em&gt;Cassia fistula&lt;/em&gt; from Karimnagar region, Telangana

In the present study, phytochemicals and anti oxidant activity of Cassia fistula from Karimnagar region of Telangana was studied. DPPH, Nitric oxide, Super oxide, Hydrogen peroxide scavenging activity of methanol bark extracts at different concentrations were studied (ascorbic acid used as standard). The present study revealed the presence of some phyto chemicals viz, tannins, poly phenols, flavonoids, quinines, terpenoids and saponins. The anti oxidant activity assay revealed significant anti oxidant activity.

Evaluation of in vitro antioxidant activities of selected commercial tea brands

The generation of reactive oxygen species requires the availability of antioxidants to ensure a balance between oxidants and prooxidants. Teas are commonly consumed due to their beneficial antioxidant effects. This study evaluated the in vitro antioxidant effects of aqueous and ethanol extracts of five selected commercial tea brands using ascorbic acid as the reference standard. The results showed that total antioxidant capacity (TAC) of aqueous extract of brand 1 was significantly lower (p&lt;0.05) compared to brand 2 with half maximal inhibitory concentration (IC50) values of 96.82 and 25.60 mg/mL respectively while the ethanol extract of all tea brands (IC50 values between 53.94 to 120.40 mg/mL) were significantly lower (p&lt;0.05) to vitamin C with IC50 of 22.72 mg/mL. In the ferric ion reducing antioxidant property (FRAP), four of the tea brands expressed none significant FRAP activities with IC50 values between 12.84 and 14.97 mg/mL compared with vitamin C with IC50 values of 17.16 mg/mL, while the ethanol extract of the brand expressed none significant FRAP activities at higher concentrations. Hydrogen peroxide scavenging activities of aqueous and ethanol extracts of all tea brands were significantly lower (p&lt;0.05) with IC50 values between 20.23 - 44.56 mg/mL and 30.53 - 36.01 mg/mL compared with vitamin C with IC50 values of 13.72 and 15.69 mg/mL respectively. Similarly, 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging property of aqueous extracts of all brands were significantly lower (p&lt;0.05) compared with vitamin C with IC50 values of 12.92 mg/mL. Furthermore, the nitric oxide scavenging property of aqueous extracts of three brands (IC50 = 18.65, 24.69 and 24.80 mg/mL) were significantly higher (p&lt;0.05) than vitamin C (IC50 = 37.75 mg/mL), while ethanol extract of three brands (IC50 = 12.81, 12.84 and 13.89 mg/mL) were significantly higher (p&lt;0.05) than vitamin C (IC50 = 32.80 mg/mL). The results of the study indicated that the selected commercial tea brands possess in vitro antioxidant properties with potential benefits of the removal of free radicals and thus the prevention of oxidative stress.

Molecular characterization and functional analysis of Schistosoma mekongi neuroglobin homolog

Schistosomes are blood-dwelling parasites that are constantly exposed to high-level oxidative stress arising from parasite-intrinsic and host defense mechanisms. To survive in their hosts, schistosomes require an antioxidant system to minimize with oxidative stress. Several schistosome antioxidant enzymes have been identified and have been suggested to play indispensable antioxidant roles for the parasite. In addition to antioxidant enzymes, non-enzymatic antioxidants including small molecules, peptides, and proteins have been identified and characterized. Neuroglobin (Ngb), a nervous system-specific heme-binding protein, has been classified as a non-enzymatic antioxidant and is capable of scavenging a variety of free radical species. The antioxidant activity of Ngb has been well-studied in humans. Ngb is involved in cellular oxygen homeostasis and reactive oxygen/nitrogen scavenging in the central and peripheral nervous systems, but its functions in schistosome parasites have not yet been characterized. In this study, we aimed to characterize the molecular properties and functions of Schistosoma mekongi Ngb (SmeNgb) using bioinformatic, biochemical, and molecular biology approaches. The amino acid sequence of Ngb was highly conserved among schistosomes as well as closely related trematodes. SmeNgb was abundantly localized in the gastrodermis, vitelline, and ovary of adult female S. mekongi worms as well as in the tegument of adult male worms. Assessment of antioxidant activity demonstrated that recombinant SmeNgb had Fe2+ chelating and hydrogen peroxide scavenging activities. Intriguingly, siRNA silencing of SmeNgb gene expression resulted in tegument pathology. Understanding the properties and functions of SmNgb will help in future development of effective treatments and vaccines against S. mekongi, other schistosome parasites, and other platyhelminths.