Hydrogen Peroxide Radical Scavenging Assays Research Articles

Antimycobacterial, antimicrobial, antioxidant activities and in silico PASS investigations of root fractions and extract of Cordia dichotoma Forst

Indian cherry (Cordia dichotoma Forst.) is a medicinally important plant widely consumed as an indigenous remedy for several ailments in the India. Although it is widely used plant by the population, there are no studies on root proving these medicinal claims. The present study was designed to investigate antimicrobial, antimycobacterial and antioxidant activities of Cordia dichotoma Forst. roots and in silico biological activities prediction using PASS. Methanolic extract was prepared and further fractions were obtained by liquid–liquid partitioning. Agar well diffusion assay and disc diffusion method were selected for antimicrobial activity. Antimycobacterial activity was estimated against Mycobacterium tuberculosis. For antioxidant activity, DPPH and hydrogen peroxide (H2O2) radical scavenging assay were employed. All the tested samples exhibited diverse pattern of sensitivity for tested strains. The value of MIC, MMC and MIC index showed that P. vulgaris and K. pneumonia were the most sensitive for ME and CF, whereas A. fumigates and V. myditis were sensitive to CF and AF. Microorganism susceptible index was 100 for P. vulgaris and K. pneumonia bacteria, and A. fumigates and V. myditis fungi. CF exhibited best activity against M. tuberculosis with lowest MIC of 30 mg/ml and highest activity index of 0.85. Dose dependent antioxidant activity was observed in both the assay. This data provides evidence that Cordia dichotoma Forst. roots have potent antibacterial, antimycobacterial, antioxidant, and moderate antifungal activity and a potential cure for infectious diseases like tuberculosis.

Antioxidant, anticoagulant and mosquitocidal properties of water soluble polysaccharides (WSPs) from Indian seaweeds

Abstract Water Soluble Polysaccharides (WSP) from three selected Indian seaweeds were extracted and fractionated by Ion Exchange Chromatography (IEC) to yield fractionated polysaccharides (FPs). Structural characterization of the FPs was performed using FT-IR and UV-Visible spectroscopy and the antioxidant properties were evaluated by total antioxidant, 2,2 diphenyl-1-picrylhydrazyl (DPPH) and Hydrogen Peroxide radical scavenging (H2O2) assays. FPs from Gracilaria filiforms demonstrated higher glucose, protein, moisture and essential mineral compositions. FPs from Gracilaria filiforms also exhibited higher scavenging activities in all the antioxidant assays. FPs from all the three seaweeds exhibited commendable anticoagulant activities. FPs from Gracilaria filiforms exhibited the maximum larvicidal activity on Anopheles stephensi (LC50 = 0.255867 mg/L) followed by Turbinaria conoides on Aedes aegypti (LC50 = 0.174348 mg/L) and Enteromorpha compressa on Culex quinquefasciatus (LC50 = 0.11175 mg/L). The results strongly establish the potentials of the FPs from the three selected Indian seaweeds as alternate functional foods and nutraceutical entities as well as mosquitocidal agents in future.

ANTIOXIDANT AND ANTIBACTERIAL ACTIVITY OF ALKALOID EXTRACT OF CUCUMIS TRIGONUS ROXB

Objective: To evaluate the antioxidant and antibacterial efficiency of alkaloids of root, leaf, and fruit of Cucumis trigonus.
 Methods: The antioxidant and antibacterial properties of alkaloid extracts were assessed by ferric thiocynate (FTC), 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay, hydrogen peroxide radical scavenging assay, superoxide radical scavenging activity and ferric reducing power were analyzed separately for its inhibition percentage at different concentration (20µg, 30µg, 40µg and 50µg/ml) and antibacterial activity by agar disc diffusion and minimum inhibitory concentration (MIC) against Staphylococcus aureus (MTCC Code-9886), Pseudomonas aeruginosa (MTCC Code-6458).
 Results: The highest percentage of extraction yield was observed in fruit followed by leaf and root. The maximum content of alkaloid was found in fruit and root compared to leaf. The scavenging efficiencies of the extracts increased with the increasing concentrations. Appreciable levels of total antioxidant activity by FTC (2.112±0.011%), DPPH radical scavenging activity (1.912±0.001%), superoxide radical scavenging activity (0.955±0.021%) and hydrogen peroxide radical scavenging activity (0.914±0.087 %) were observed at 50µg/ml of fruit extract. However, ferric reducing power was more in the root (0.893±0.0870%) compared to fruit (0.791±0.023%) and leaf (0.520±0.00 %) at 50µg/ml. The alkaloid extracts of root and fruit exhibited more antibacterial activity against Staphylococcus aureus (16.51±0.05 and 19.68±0.03 mm) and Pseudomonas aeruginosa (12.2±0.03 and14.2±0.06) at 100µg/ml than leaf. The minimum inhibitory concentration (MIC) of the root, leaf, and fruit was in the range of 3.125µg/ml to 35µg/ml for the pathogenic bacteria.
 Conclusion: Data from the present results revealed that the alkaloid extracts of fruit and root of C. trigonus show good antioxidant and antibacterial potential than leaf. Hence, may be explored for the formation of new antibacterial with antioxidant drugs.

A COMPARATIVE SCREENING AND EVALUATION OF THE TOTAL PHENOLICS, FLAVONOIDS, AND ANTIOXIDANT PROPERTIES IN THE SEED EXTRACTS OF PUNICA GRANATUM L., PSIDIUM GUAJAVA L., AND VITIS VINIFERA L.

Objectives: The synthetic antioxidants produce numerous adverse effects to overcome these adverse effects and the use of natural products is the alternative. In this study, the evaluation of total phenolics, flavonoid contents, and antioxidant properties of Punica granatum, Psidium guajava, and Vitis vinifera seed extracts was done.
 Methods: The total phenolic content was estimated with gallic acid equivalent and the total flavonoid contents were estimated on quercetin equivalent. For the antioxidant properties of selected seed extracts, the 2,2-diphenyl-1-picrylhydrazyl radical scavenging, ferrous reducing power, and hydrogen peroxide radical scavenging assays were followed to find the free radical scavenging ability of the selected seed extracts.
 Results: The ethyl acetate extract of P. granatum seed contains higher phenolic content (70.25±1.25 μg/ml) and flavonoid content (58.15±1.85 μg/ml) and possesses a high free radical scavenging ability. Based on the inhibitory effects of fruit seeds against synthetic radicals, they can be ranked as P. granatum>P. guajava>V. vinifera.
 Conclusion: According to overall observations of the study, the pomegranate seed extract contains a higher level of phenolic and flavonoid contents and shows a higher scavenging effect against free radicals among the others seeds. Phytochemical screening showed that the ethyl acetate extract of pomegranate fruit seed possesses more secondary metabolites compared to other seed extracts.

COLLECTION, IDENTIFICATION, MOLECULAR CHARACTERIZATION, AND ANTIOXIDANT ACTIVITY OF NON-GILLED MUSHROOMS COLLECTED FROM NORTH WESTERN HIMALAYAS

Objective: The objective of present research deals with collection, taxonomic, molecular taxonomy characterization, and antioxidant activity of wild non-gilled mushrooms sample collected from North Western Himalayas.Methods: The wild non-gilled mushroom samples were characterized for micro, morphological properties, and molecular identification. 1,1 diphenylpicrylhydrazyl (DPPH), nitric oxide (NO2), hydrogen peroxide (H2O2), and free radical scavenging assay were used to evaluate the antioxidant properties of selected wild non-gilled mushrooms.Results: The obtained results revealed that on the basis of microscopic and morphological identification all the four non-gilled mushrooms samples were tentatively identified as 2/15 (Auricularia sp.1), 6/15 (Auricularia sp.2), 32/15 (Ganoderma sp.), and 132/15 (Trametes sp.). The colony, mycelial, and basidiospore morphology of fungal isolate were evidence of Basidiomycetes family. All these four non-gilled mushrooms were sequenced. Sequences were submitted to National Center for Biotechnology Information (NCBI), and their accession number was MF770159 (2/15), MF774107 (6/15), MF770158 (32/15), and MF770160 (132/15). The phylogenetic analysis of 18S ribosomal deoxyribonucleic acid (18S rDNA) sequence of four non-gilled mushrooms was compared with other species and identified as Auricularia polytricha, Ganoderma lucidum, Auricularia auricula-judae, and Trametes elegans. The four non-gilled mushrooms extract exhibited DPPH, NO2, and H2O2 free radical scavenging activities. G. lucidum methanolic extract has the highest effect on free radicals in comparison to hexane effect.Conclusion: All the isolated four non-gilled mushrooms showed good antioxidant potential, and it can be concluded that these mushrooms are not only consumed but also have a wide range of medicinal properties which must further explode for future use.

PHARMACOLOGICAL STUDIES: ANTIBACTERIAL, ANTIOXIDANT, AND ANTI-INFLAMMATORY EFFICACY OF CASUARINA EQUISETIFOLIA ROOT EXTRACTS

Objective: The current study was aimed to investigate the potential phytoconstituents from Casuarina equisetifolia root extract. Qualitative, quantitative and gas chromatography–mass spectrometry (GC-MS) analysis of C. equisetifolia using various solvents of root extract was also carried out to characterize the presence of various bioactive compounds in the root. The research work was also targeted to reveal the antibacterial, antioxidant, and anti-inflammatory potential of the root extract of C. equisetifolia.Methods: Root samples of C. equisetifolia were collected from Nimilenchery village, Pondicherry Union territory. The qualitative screening of the root extracts was carried out to check the presence of various phytoconstituents which was then followed by the quantitative analysis of phenols, flavonoids, and tannins. Further, the phytochemicals in the root extract were evaluated using GC-MS studies. In vitro antibacterial activity was performed by the agar well diffusion method using aqueous and organic solvent-based root extract against four different bacterial pathogens. In vitro antioxidant assay of different solvent extracts was elucidated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, hydrogen peroxide radical scavenging assay, and reducing power assay. Anti-inflammatory potential was also studied using protein denaturation of albumin.Results: The qualitative phytochemical screening revealed the presence of various phytoconstituents which is of greater biological importance. Gallic acid equivalent (GAE) phenolic compound content (68.64±0.25 mg GAE/g of extract), quercetin equivalent flavonoid content (29.09±0.14 mg of QUE/g of extract), tannic acid equivalent (TAE) tannin content (51±0.42 mg TAE/g of extract), and terpenoid content (5.2%) were found to be significant in the methanol root extract of C. equisetifolia when compared with other solvents. GC-MS analysis revealed different peaks indicating the presence of different secondary metabolites. Prominent antibacterial activity was observed in methanol extract of root, with maximum zone of inhibition exhibited against Proteus vulgaris (23.45±0.28 mm). The methanol root extract was most effective with half maximal inhibitory concentration (IC50) 52.74±0.65 μg/ml for DPPH and 64.94±0.24 μg/ml for hydrogen peroxide scavenging activity. Maximum absorbance was observed by 80 μg/ml (IC50 51.79±0.26 μg/ml) of methanol root extract with respect to reducing power assay. In vitro anti-inflammatory activity had maximum inhibition of 84.6±0.26 with IC50 value of 33.6±0.23 μg/ml at 80 μg/ml.Conclusion: From this study, it is revealed that the species of C. equisetifolia is a source of potential phytoconstituents exhibiting significantly various biological activities leading to the development of novel drug.

Metabolic Profiling and Chemical-Based Antioxidant Assays of Green and Red Lettuce (Lactuca sativa)

Lettuce ( Lactuca sativa) is an important leaf vegetable crop worldwide. The total phenolic content was higher in the red skirt methanol extracts with a level of 64.9 ± 0.3 mg GA/g, and phenolic content of green skirt was 49.4 ± 0.3 mg GA/g. The total flavonoid content in the methanol extract of red skirt showed the highest concentration (291.6 ± 9.0 mg rutin/g), followed by green skirt (223 ± 9.8 mg rutin/g). The red skirt showed a higher content of anthocyanin (23.7 ± 0.8 mg/100 g) compared to the green skirt (7.4 ± 0.9 mg/100 g). Seven carotenoids i.e., lutein, β–carotene, 9 Z–β–carotene, 13 Z–β–carotene, violaxanthin, zeaxanthin, and α–carotene were detected in both cultivars. The polar metabolites are strongly associated with the metabolites that participate in the TCA cycle. Correlations between primary and secondary metabolites were easily achieved by gas chromatography-time-of-flight mass spectrometry (GC-TOFMS)-based metabolite profiling method. Red skirt methanol extract showed 77.5 ± 0.4% 2,2-diphenyl-1-picrylhydrazyl (DPPH) activity, 50.8 ± 0.8% hydrogen peroxide radical scavenging assay and absorbance value (0.052) reducing power assay at 250 μL/mL, having significantly higher activity than the green skirt extract. The red lettuce extract also showed higher levels of phenolic compounds, flavonoids, and anthocyanins, and it possesses more antioxidant properties compared to the green skirt extract. In this study we compared two cultivars of lettuce, red skirt and green skirt, for various nutritional parameters and to understand the association of secondary metabolites with their corresponding primary metabolites. From the overall analysis, it is confirmed that GC-TOFMS-based metabolite profiling is an appropriate method for determining biochemical reactions and also acts as a combined resource to understand primary and secondary metabolism.

Synthesis and Antioxidant Activity of Some New Coumarin Incorporated 4-Thiazolidinone Derivatives

A series of new 4-thiazolidinone derivatives were synthesized by reacting various coumarinyl schiff bases with thioglycollic acid. The intermediate coumarinyl schiff bases were synthesized by reacting 4-hydroxyl coumarin with various substituted anilines in alcohol medium. All the newly synthesized compounds were assigned on the basis of IR, 1H NMR and mass spectral data. All the newly synthesized compounds were evaluated for in-vitro antioxidant activities like DPPH, nitric oxide and hydrogen peroxide radical scavenging assay models. Most of the synthesised compounds showed good antioxidant activity.

Evaluation of antiangiogenic potential of Psidium guajava leaves using In-Ovo chick chorioallantoic membrane assay

Background: Angiogenesis is the process of formation of new blood vessels from the existing one. Pathological angiogenesis is widely implicated in many diseases, including cancer, diabetic neuropathy, retinopathy, obesity, and arthritis. Objective: The present study was aimed to evaluate the in vitro antioxidant and in ovo antiangiogenic activity of aqueous extract of Psidium guajava leaves (AEPG). Materials and Methods: Psidium guajava commonly known as guava reported to contain polyphenols and flavonoids such as gallic acid, epigallocatechin, catechin, rutin, and quercetin in glycosidic forms in its leaves. The antioxidant activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS), nitric oxide, hydrogen peroxide, hydroxyl, and superoxide radical scavenging assays (RSAs) and antiangiogenic activity was evaluated using vascular endothelial growth factor (VEGF)-induced chick chorioallantoic membrane (CAM).The correlation between the antioxidant and antiangiogenic activity was correlated with total phenolic content (TPC) of AEPG. Results: The TPC of AEPG was found to be 493.8 ± 8.9 mg of GAE/g. The total flavonoid content of AEPG was found to be 254.9 ± 13.7 mg of CE/g. In vitro antioxidant activity of AEPG showed IC50 values of 19.4 ± 1.9, 25.5 ± 0.2, 4.9 ± 0.5, 29.9 ± 2.06, 39.5 ± 2.07, and 29.9 ± 0.9 μg/ml, respectively, for DPPH, ABTS, nitric oxide, hydrogen peroxide, hydroxyl, and superoxide RSAs. Significant reduction in angiogenesis in the AEPG treated groups when compared to untreated VEGF groups and the Pearson's correlation coefficient between TPC of AEPG and total length, area, branches of blood vessels and CAM thickness were −0.9261, −0.9807, −0.9637, and −0.9597, respectively. Conclusion: The results revealed potent antiangiogenic activity of AEPG leaves and exhibit significant correlation between the antioxidant and antiangiogenic activity of AEPG and its TPC. Abbreviations used: EGF: Epidermal growth factor; FGF: Fibroblast growth factor; G-CSF: Granulocyte colony stimulating factor; IL: Interleukin; INF: Interferon; MMP: Matrix metalloproteinases; NOS: Nitric oxide synthase; PAF: Platelet-activating factor; PAI: Plasminogen activator inhibitor; PDGF: Platelet-derived growth factor; PG-E: Prostaglandin E; RSA: Radical scavenging assay; TFC: Total flavonoid content; TPC: Total Phenolic content; TIMP: Tissue inhibitors of metalloproteinases; TNF-α: Tumor necrosis factor alpha; VEGF: Vascular endothelial growth factor.

Green Synthesis and Antioxidant Study of Silver Nanoparticles of Root Extract of Sageretia thea and Its Role in Oxidation Protection Technology

Development of environmentally friendly synthesis of nanoparticles is one of the important areas of research in nanotechnology. In present study silver naopartticles (AgNPs) of root extract of Sageretia thea (S. thea) were synthesized at room temperature. The synthesized AgNPs were characterized by UV. Visible spectroscopy (UV), scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive spectroscopy (EDX), transmission electron microscopy (TEM), dynamic light scattering (DLS) and Fourier transform infrared (FT-IR) spectroscopy. Formation of AgNPs was confirmed by visual examination the colour change from yellow to brick red due to surface Plasmon resonance band at 435 nm. SEM and TEM analysis of synthesized AgNPs revealed spherical morphology with average particle size 25 nm. Crystalline nature of the AgNPs in face centered cubic structure is evident from the selected area electron diffraction (SAED) and XRD pattern. The presence of elemental Ag was confirmed by EDX analysis at 3kv. Different functional groups which responsible for reduction and stabilization of reaction medium was confirmed by FTIR spectroscopy. The biosynthesized AgNPs showed strong DPPH and dye protection radical scavenging assay while modest hydrogen peroxide radical scavenging assay as compare to crude extract. The present investigations suggest that biosynthesized nanoparticles have a high potential for use in the preparation of drugs used against various diseases and also a promising candidate for many medical applications.

Radical scavenging potency of 2-(benzofuran-2-yl)-2-oxoethyl 3-(methyl/amino)benzoate: synthesis, crystal structure and Hirshfeld surface analysis

Abstract Two novel 2-(benzofuran-2-yl)-2-oxoethyl 3-(methyl/amino)benzoates 2(a–b), were synthesized under mild conditions and characterized by spectroscopic analysis. The three-dimensional (3D) crystal structures of these compounds were further determined using single crystal X-ray diffraction technique and revealed that both compounds tend to twist away with respect to their attached carbonyl groups at the C(=O)–C–O–C(=O) connecting bridge, exhibiting a nearly perpendicular conformation with torsion angle in a range of 75–94°. In both compounds, each of the benzofuran and substituted phenyl rings are individually planar while almost perpendicular to each other. Their molecular conformation are comparable with related structures from the Cambridge Structural Database (CSD). Furthermore, the intermolecular interactions in these crystal structures were quantified and analyzed using Hirshfeld surfaces computational method. The quantitative data on the percentage contributions of overall interactions on the molecules 2a and 2b (A & B) is calculated by the 2-D fingerprint plots from the HS analysis. These structures were evaluated for their antioxidant properties by diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, ferrous ion chelating (FIC) and hydrogen peroxide radical scavenging assays (H2O2). Noteworthy, compound 2b with an amino substituent attached to the phenyl ring exhibited an IC50 value of 45.37 μg/mL in H2O2 scavenging assay, which showed better scavenging effect than the standard drug, ascorbic acid (IC50=81.02 μg/mL).

Antioxidant properties of the carotenoid extracts of three Deinococcus\u2013Thermus phylum bacteria, Meiothermus sp. strains RP and TP and Thermus sp. strain YY from Paniphala hot spring, India

BackgroundThe purpose of the study was to extract carotenoids from thermophilic bacteria which show efficient antioxidant and protein oxidation inhibition properties, characterize and identify those isolates, extract the carotenoids in different solvents, quantify the carotenoids and perform concentration-dependent and solvent-dependent quantitative assays validated and analysed by appropriate statistical tests.MethodsThree pigment-forming thermophilic strains were isolated from water sample of Paniphala hot spring, India, and tentatively identified by 16S ribosomal DNA (rDNA) homology. Different concentrations of the carotenoid extracts (100, 80, 40 and 20 μg) in three solvents, methanol, DMSO and water, were used to determine the antioxidant activity through five methods: the DPPH (1,1-diphenyl-2-picrylhydrazyl) assay, the ABTS (2,2-azino-bis (3-ethylbenz-thiazoline-6-sulfonic acid)) assay, the hydrogen peroxide assay, TOC (total antioxidant capacity) assay and inhibition of protein oxidation assay. Statistical analysis of mean, standard deviation, ANOVA and Pearson correlation coefficient was performed in Microsoft Excel statistical package.ResultsThe isolates were tentatively identified as Meiothermus sp. strain RP, Meiothermus sp. strain TP and Thermus strain YY. Meiothermus sp. formed red coloured pigment, whereas Thermus sp. formed yellow coloured pigment. All of the extracts showed positive results in DPPH assay, ABTS assay and hydrogen peroxide radical scavenging assay with best results obtained when the extracts were dissolved in water. Total antioxidant capacity assay was also high in all the extracts. Protein oxidation inhibition activity was only seen in extracts of strain YY. One-way ANOVA (analysis of variance) clearly showed that choice of solvent influenced the antioxidant capacity of all of the extracts.ConclusionsNewer and efficient antioxidative compounds are constantly being searched for, and the carotenoid extracts of RP, TP and YY have been shown to catalyze various types of antioxidative reactions, including protein oxidation inhibition by YY. Thus, all these extracts have huge potential to be industrially and pharmaceutically useful.

IN VITRO ANTIOXIDANT ACTIVITY OF VARIOUS LEAF EXTRACTS OF CANTHIUM COROMANDELICUM(BURM.F.) ALSTON.

Objectives: The objective of this study was to estimate the total phenolic and flavonoid contents and to explore the antioxidant potential of various leaf extracts (chloroform, ethyl acetate, and ethanol) of Canthium coromandelicum, which is considered traditionally as an important medicinal plant.Methods: Antioxidant properties of the extracts were assessed using 1, 1- diphenyl -2- picrylhydrazyl and hydrogen peroxide radical scavenging assays for ascorbic acid equivalents. The total phenolic and flavonoid contents were also investigated to determine their correlation with the antioxidant activity of the leaf extracts and expressed in Gallic acid and quercetin equivalents, respectively.Results: The results showed that the content of total phenols and flavonoids was found to be high in ethyl acetate extract which was recorded as 61.02±1.30 mg Gallic acid equivalent (GAE/g) and 81.72±0.61 QE/g, respectively. Compared to other extracts, ethyl acetate leaf extract was found to possess high antioxidant activity at p<0.05 level, with high percentage of inhibition at 100 μg/ml concentration (82.70%) toward hydrogen peroxide radical scavenging with IC50 value 62.94 μg/ml. Statistically, two-tailed Pearson’s correlation showed strong positive correlations between hydrogenperoxide radical scavenging activity and total phenolic contents (TPC) (r=1.000) at p<0.05 level.Conclusion: The results obtained in this study clearly signifies that the ethyl acetate leaf extract of C. coromandelicum has high content of total phenols which are correlated to its antioxidant activity and thus has the potential to use as a source of natural antioxidants and can be explored as a therapeutic agent in free radical induced diseases.Keywords: Canthium coromandelicum, In-vitro antioxidant activity, Ethyl acetate extract, Pearson’s correlation, 1, 1- diphenyl -2- picrylhydrazyl, Hydrogen peroxide, Nitric oxide, Superoxide.

Design, synthesis and evaluation of some N-methylenebenzenamine derivatives as selective acetylcholinesterase (AChE) inhibitor and antioxidant to enhance learning and memory

Series of some 3,5-dimethoxy-N-methylenebenzenamine and 4-(methyleneamino)benzoic acid derivatives comprising of N-methylenebenzenamine nucleus were designed, synthesized, characterized, and assessed for their acetylcholinesterase (AChE), butyrylcholinesterase (BChE) inhibitory, and antioxidant activity thereby improving learning and memory in rats. The IC50 values of all the compound along with standard were determined on AChE and BChE enzyme. The free radical scavenging activity was also assessed by in vitro DPPH (2,2-diphenyl-1-picryl-hydrazyl) and hydrogen peroxide radical scavenging assay. The selective inhibitions of all compounds were observed against AChE in comparison with standard donepezil. The enzyme kinetic study of the most active compound 4 indicated uncompetitive AChE inhibition. The docking studies of compound 4 exhibited the worthy interaction on active-site gorge residues Phe330 and Trp279 responsible for its high affinity towards AChE, whereas lacking of the BChE inhibition was observed due to a wider gorge binding site and absence of important aromatic amino acids interactions. The ex vivo study confirmed AChE inhibition abilities of compound 4 at brain site. Further, a considerable decrease in escape latency period of the compound was observed in comparison with standard donepezil through in vivo Spatial Reference Memory (SRM) and Spatial Working Memory (SWM) models which showed the cognition-enhancing potential of compound 4. The in vivo reduced glutathione (GSH) estimation on rat brain tissue homogenate was also performed to evaluate free radical scavenging activity substantiated the antioxidant activity in learning and memory.

Preliminary assessment of free radical scavenging, thrombolytic and membrane stabilizing capabilities of organic fractions of Callistemon citrinus (Curtis.) skeels leaves.

BackgroundCallistemon citrinus (Curtis.) (Family- Myrtaceae) is a popular evergreen shrub in Bangladesh. In the present study, the leaves of this plant have been assessed comprehensively for free radical scavenging, thrombolytic and membrane stabilizing activities.MethodsThe leaves were collected, powdered and extracted with methanol. The extract was then concentrated and successively fractionated into petroleum ether, carbon tetrachloride, chloroform and aqueous soluble fractions. The extractives were investigated for free radical scavenging, thrombolytic and membrane stabilizing activities.ResultsIn case of 1,1 diphenyl-2-picrylhydrazyl (DPPH) and hydrogen peroxide radical scavenging assays, the crude methanol extract of the leaves showed the highest free radical scavenging activity among the tested materials including standard ascorbic acid (p = 0.0000). Besides, this extract was also found significantly rich (p = 0.0000) in phenolics and flavonoids compared to other organic fractions. In thrombolytic study, the petroleum ether fraction exhibited significantly stronger thrombolysis (p = 0.024) than other leaf extractives but was weaker than the standard streptokinase. In membrane stabilizing assay, the activity of chloroform fraction was similar to that of standard acetylsalicylic acid (p = 1.000) in hypotonic solution induced hemolysis. However, membrane stabilization activity of this chloroform fraction was found significantly stronger than that of the standard (p = 0.0000) in heat induced hemolysis.ConclusionThis study has revealed the medicinal capabilities of different organic fractions of C. citrinus displaying free radical scavenging, thrombolysis and membrane stabilizing antiinflammatory potentials. Further bioactivity guided isolation is required to obtain pharmacologically secondary metabolites.

Development of an antidiabetic polyherbal formulation (ADPHF6) and assessment of its antioxidant activity against ROS-induced damage in pUC19 and human lymphocytes - an in vitro study.

Polyherbalism, an alternative natural-based therapy for various disorders, has been quoted about 1,300 years before in Sharangdhar Samhita. Herbal-based combination therapy stages a vital role for the treatment of type 2 diabetes mellitus (T2DM) and associated complications. The present study aims at developing an Ayurvedic-based polyherbal formulation (ADPHF6) and the assessing its antidiabetic and antioxidant property. ADPHF6 polyherbal formulation was measured for phytochemical components by qualitative methods. The polyherbal formulation was quantitatively estimated for its phytochemical constituents, i. e. total phenol and flavonoid content. Further, the antioxidant property of ADPHF6 formulation was evaluated by 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) radical scavenging assay, hydrogen peroxide radical scavenging assay and metal chelating assay. α-Amylase and α-glucosidase inhibitory activities of polyherbal formulation were also assessed. ADPHF6 was further analysed for its protective antioxidant property against reactive oxygen species (ROS‾)-induced damage in human lymphocyte DNA and pUC19 plasmid. ADPHF6 polyherbal formulation revealed the presence of phytochemical constituents such as alkaloids, flavonoids, phenols, tannins, terpenoids, saponins and cardiac glycosides in significant levels. Further, it also measured the higher levels of total phenols (473.3±3.05 mg/g) and flavonoid (664±5.29 mg/g) content. Polyherbal formulation also exhibited IC50 values of 49.9±0.15, 65.1±0.10 and 60.1±0.05 mg/mL for 2,2- diphenyl-1-picryl-hydrazyl-hydrate (DPPH), hydrogen peroxide (H2O2) and Fe2+ radical scavenging activities, respectively. ADPHF6 revealed an inhibitory activity (IC50) of 0.67±0.01 and 0.81±0.01 mg/mL for α-amylase and glucosidase, respectively. Pre-treated human peripheral blood lymphocytes with ADPHF6 aqueous extract illustrated enhanced protection against ROS-mediated damage as compared with post-treated groups. DNA nicking assay rendered protective activity against the OH¯ radical-induced DNA damage in supercoiled pUC19 plasmid. Our present study demonstrates that ADPHF6 offers potent inhibitory activity against free radicals as well as digestive enzymes. However, studies should be conducted using in vivo model to further elucidate the effect against free radicals and its anti-hyperglycaemic activity in the management of non-insulin-dependent diabetes.

In vitro Antioxidant and Antibacterial Activities of Methanol Extract of Kyllinga nemoralis.

The present study was designed to evaluate the antioxidant and antibacterial activity of methanol extract of Kyllinga nemoralis. Six different in vitro antioxidant assays including 2,2-diphenyl-1-picrylhydrazyl, hydroxyl radical, superoxide anion radical, hydrogen peroxide radical, ferric reducing antioxidant power assay and reducing power were carried out to ensure the scavenging effect of the plant on free radicals. In addition, total antioxidant capacity assay, total phenolic contents, tannins, flavonoids and flavonol contents of the plant were also analysed by the standard protocols. Kyllinga nemoralis exhibited high antioxidant activity on 2,2-diphenyl-1-picrylhydrazyl assay (IC50= 90 μg/ml), superoxide radical scavenging assay (IC50= 180 μg/ml) and hydrogen peroxide radical scavenging assay (IC50= 200 μg/ml), compared with standards. These observations provide comprehensible supporting evidence for the antioxidant potential of the plant extract. Reducing power (IC50= 213.16 μg/ml) and hydroxyl radical scavenging activity (IC50= 223 μg/ml) of the plant extract was remarkable. The methanol extract of K. nemoralis exhibited significant antimicrobial activity against Gram-positive human pathogenic bacteria. Standard in vitro antioxidant assays assessed the electron donating ability of the plant extract in scavenging free radicals. The inhibitory effect of the plant extract against bacterial pathogens may be due to the presence of phytochemicals. Thus, the results suggest that Kyllinga nemoralis is a potential source of antioxidants and could serve as the base for drug development.

SYNTHESIS AND ANTIOXIDANT EVALUATION OF NOVEL PHENOTHIAZINE LINKED SUBSTITUTEDBENZYLIDENEAMINO-1,2,4-TRIAZOLE DERIVATIVES

ABSTRACT A series of novel 5-((10 H -phenothiazin-10yl)methyl)-4-(substitutedbenzylideneamino)-4 H -1,2,4-triazole-3-thiol derivatives (6a-i) have been synthesized from compound (1) through a multi-step reaction. The key intermediate (5) afforded a series of title compounds (6a–i) on condensation with various suitable aldehydes in the presence of H 2 SO 4 . The structures of novel compounds were characterized based on their elemental analysis, IR, 1 H-NMR, 13 C-NMR and MS spectral data. All these novel compounds were screened for their in vitro antioxidant activity by employing nitric oxide, hydrogen peroxide, and DPPH radical scavenging assays. The compounds 6d, 6e and 6i demonstrated potent antioxidant activity as these contain the electron-releasing groups. Keywords: Synthesis, Anti-oxidant activity, 1,2,4-Triazole, Phenothiazines. INTRODUCTION The heterocyclic compounds chemistry continues to be an emerging field in the organic and pharmaceutical chemistry 1 . Heterocyclic compounds are present in various drugs, several natural products, some vitamins, biomolecules, and biologically active compounds such as anti-inflammatory, antitumour, antimalarial, antidepressant, anti-HIV, antibiotic and antimicrobial agents etc

In-vitro Screening for Acetylcholinesterase enzyme Inhibition potential and Antioxidant Activity of Extracts of Ipomoea Aquatica Forsk: Therapeutic lead for Alzheimer's disease

Alzheimer’s disease (AD) is a primary degenerative disease of the central nervous system. The progression of Alzheimer’s disease will ultimately lead to dementia, behavioral and cognitive impairments. Increased level of the enzyme acetylcholinesterase AChE plays a key role in hydrolysis of the neurotransmitter Acetylcholine (ACh) which worsen the condition of cognitive dysfunction. Several drug of natural origin are known to possess AChE inhibition and antioxidant activity .The main objective of the present study is to evaluate AChE inhibition and antioxidant activity of the plant Ipomoea Aquatica Forsk .Leaves of Ipomoea Aquatica Forsk was extracted with Chloroform, n-Hexane, Ethanol and mixture of Ethanol: water (6:4) (hydro-alcoholic extract) using soxhlet extraction. All the four extracts were examined for In-Vitro anti-cholinesterase by Ellman’s method and antioxidant activity by DPPH and Hydrogen peroxide radical scavenging assay. Results obtained from the study clearly demonstrates that all four extract has shown promising acetylcholinesterase inhibition activity in hydro alcoholic extract reveals the best inhibition potential with IC50 49.03 μg /ml .Similarly all the extracts projects significant antioxidant activity in DPPH assay with IC50 value ranging from 19.64 to 88.63 μg /ml and in Hydrogen peroxide assay with IC50 value ranging from 56.79 to 137.3 μg /ml.

Nutritive Values and Antioxidant Activity of <i>Citrullus lanatus</i> Fruit Extract

Citrullus lanatus (Watermelon) is a fruit cultivated and consumed in Africa for its essential nutrients which are very beneficial to the human body. The present study was designed to evaluate the nutritive contents, free radical scavenging activities and phytochemical components of C. lanatus fruit. The extract of the fruit was subjected to in vitro antioxidant assessment using 1,1-di-phenylpicryl-hydrazyl radical (DPPH) and hydrogen peroxide radical scavenging assays. The proximate and phytochemical analyses were conducted using standard procedures. The results of this study showed that C. lanatus fruit had very high moisture content and its crude protein, crude fat, crude fibre and ash content were all in traceable amounts. The sugar content was considerably high in comparison with other nutritive contents. Lycopene and β-carotene contents of C. lanatus fruit were estimated to be 4537.83 and 308.71 μg/100g respectively. The gross energy evaluation showed a value of 0.335 Kcal/g. The fruit extract exhibited significant (p < 0.05) DPPH (IC50 of 0.10 mg/ml) and hydrogen peroxide radicals scavenging activity (IC50 of 0.62 mg/ml) in comparison with the positive control butylated hydroxytoluene (BTH). This study therefore recommends that C. lanatus fruit could be an excellent source of antioxidants which may prevent diseases whose pathogenesis involves oxidative stress.