Cupric-reducing Capacity Research Articles

Phenolic Content and Antioxidant Activity of Hydroethanolic and Aqueous Extracts of the Inflorescences of Allium sphaerocephalon L.

The objective of this effort is to quantify the amounts of phenolics and the in vitro antioxidant capacities of Allium sphaerocephalon L. flowers’ hydroethanolic (EOH) and aqueous (AQE) extracts. The two extracts' total phenolic (TPC) and flavonoid content (TFC) were determined spectrophotometrically. Results showed the extraction yield obtained by EOH and AQE were 18.30% and 11.80%, respectively. The EOH gave higher amounts of TPC (12.73±0.91µg GAE/mg DW) and TFC (7.67±0.24µg QE/mg DW) than AQE (TPC = 9.71±0.53µg GAE/mg DW and TFC= 5.68±0.90µg QE/ mg DW). Five techniques were used to train antioxidant activity. The EOH extract had high activity in DPPH radical scavenging capacities and β-carotene bleaching assay, while the AQE extract had high activity in metal chelating ions and reducing power assay. However, both extracts had no different significance in cupric-reducing capacity. A moderate quantity of flavonoids and polyphenols, as well as a satisfactory level of antioxidant activity, were observed in both preparations derived from the flowers of A. sphaerocephalon L., where this activity is not all fully related to the amount of phenolic compounds.

Cladonia rangiformis Acetone Extract— New Insight into the Chemical Composition and Biological Activity

Introduction Cladonia rangiformis, also known as reindeer lichen, has been used for various remedies in folk medicine. The rich nutritional value of this lichen is reflected in the fact that it contains atranorin, which has been proven to have numerous biological activities. Objective The chemical composition, antioxidant, anticholinesterase, and antigenotoxic activities of the C. rangiformis acetone extract were investigated. The novelty of this work is that anticholinesterase activity, protective effect on human lymphocytes, and antioxidant activity by the cupric-reducing antioxidant capacity (CUPRAC) method of C. rangiformis extract were determined for the first time, as well as gas chromatography - mass spectrometry (GC-MS) profile. Methods Chemical composition was carried out by high-performance liquid chromatography (HPLC)-diode array detector and GC-MS. Antigenotoxic effect was evaluated in human lymphocytes by cytokinesis-block micronucleus assay. Total phenolic content, DPPH and ABTS radical scavenging capacities, CUPRAC, and total reducing power were determined spectrophotometrically. Determination of acetylcholinesterase activity was performed by Ellman's colorimetry assay. The statistical analysis of variance (One-way ANOVA) was performed using Origin software package version 7.0. Results HPLC method was used to identified 3 compounds with atranorin as predominant constituent (97.2%). Fumarprotocetraric and atraric acid were represented in a much smaller mutually approximate amount, 0.3 and 0.5%, respectively. Rangiformic acid was the most abundant volatile compound. Acetone extract of C. rangiformis (2 μg/mL) decreased the frequency of micronuclei by 15.5% while the radioprotectant amifostine reduced the frequency of occurrence of micronuclei by 11.4%. On the contrary, at a concentration of 1.0 mg/mL the extract exhibited an activating effect on cholinesterase (2.0%), while at a concentration of 10.0 mg/mL it showed a weak inhibitory effect (7.3%). The total phenol content was 132.71 μg gallic acid equivalents per mg of dry extract. The IC50 value for the DPPH experiment was 16.19 mg/mL and for ABTS was 11.80 mg/mL. Cupric reducing capacity and total reducing power were 17.81 μg Trolox equivalents per mg of dry extract and 0.45 μg ascorbic acid equivalents per mg of dry extract, respectively. Conclusion In addition to previously identified compounds in the acetone extract, atraric acid was identified for the first time by using HPLC method, and orcinol, β-orcinol, lauric alcohol, atranol, and rangiformic acid by using GC-MS method. The results of biological activity proved that acetone extract had antioxidant capacity and weak anticholinesterase activity. Reduction of the number of micronuclei in human lymphocytes, classified C. rangiformis as promising substances source with beneficial effects on DNA damage.

In vitro Comparative Studies of the Leaf Extracts of Four Different Types of Calamus Species

The leaf extracts of Calamus tenius, Calamus viminalis, Calamus guruba and Calamus erectus possessed various phytochemicals including alkaloids, carbohydrates, saponins, phenols, tannins, flavonoids, glycosides, fixed oils and steroids. The point of the present investigation was to compare the antioxidant profile of different leaf extracts of these species. In the present study, methanol, ethanol and chloroform extract of leaf of C. tenius, C. viminalis, C. guruba and C. erectus were explored for in-vitro thrombolytic activity, membrane stabilizing activity by using hypotonic solution-induced & heat-induced hemolysis and antioxidant profile. Ethanol extracts of all plant species demonstrated the highest percentage of clot lysis. During hypotonic solution-induced hemolysis, methanol extract of C. erectus inhibited 59.74% whereas during heat induced condition ethanol extracts of all plant species demonstrated the highest percentage inhibition of hemolysis of RBCs. The screenings of the plants revealed that leaf extracts contain phenolic and flavonoid contents in great amount with the high level of antioxidant capacity. The chloroform extract of C. tenius (2.45 μg/ml) and methanol extract of C. erectus (1.74 μg/ml) leaf showed potent DPPH and H2O2 scavenging activity, respectively. The nitric oxide scavenging activity was not significantly different for methanol, ethanol and chloroform extracts. Methanol, ethanol and chloroform extracts of these four plants showed medium to moderate reducing power and cupric reducing capacity in comparison to standard. A strong relationship was found between the antioxidant activity of the extracts with their total phenolic and flavonoid contents. Dhaka Univ. J. Pharm. Sci. 21(2): 173-181, 2022 (December)

The Crystal Structure, Hirshfeld Surface interactions, optical/Nonlinear Optical properties and evaluation of the antioxidant activity of 8-(3-chloropropanamido)quinolin-1-ium chloride: Experimental and theoretical studies

The title compound, 8-(3-chloropropanamido)quinolin-1-ium chloride, (C12H11ClN2O)+·Cl− (Q1), was synthesized via the reaction of quinolin-8-amine with 3-chloropropanoyl chloride. It was characterized by single-crystal X-ray diffraction analysis, and by infrared, and 1H and 13C NMR spectroscopies. Hirshfeld surface analysis and two-dimensional fingerprint plots were used to quantify the interatomic interactions present in the crystal. The antioxidant activity of the synthesized compound was evaluated by the 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH) radical scavenging, cupric reducing capacity (CUPRAC) and ABTS radical scavenging activity, showed an average inhibition. The molecular structure of Q1 is determined by DFT calculations at wb97xd/6-311g(d) levels. Local and global reactivity descriptors were computed to predict the reactivity of the title compound. Furthermore, TD-DFT calculation is also used to determine the optical properties of the Q1 in the gas and solvents. We found excellent agreement between the calculated results and the experimental data. Moreover, the quantum calculations showed that the title compound is a potential candidate for second- and third-order NLO applications

Dimethoxyindoles based thiosemicarbazones as multi-target agents; synthesis, crystal interactions, biological activity and molecular modeling

Alzheimer’s disease (AD) is known as one of the most devastating neurodegenerative disease diagnosed for the old-aged people and cholinesterase inhibitors (ChEI) can be used as an effective palliative treatment for AD. A range of novel monomeric and dimeric indole based thiosemicarbazone derivatives 17–28 was synthesized in order to target cholinesterases (ChE). Biological importance of the targeted compounds 17–28 was investigated by employing the acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes along with three different antioxidant property determination assays, namely DPPH free radical scavenging, ABTS cationic radical decolarization, and CUPRAC cupric reducing antioxidant capacity. The compounds 18 and 19 displayed the best inhibitor activity against BChE with IC50 values of 7.42 and 1.95 μM, respectively. The antioxidant potentials were found to be moderate for DPPH and ABTS assays and the compounds 28 and 18 were the most potent candidates for both antioxidant assays. Cupric reducing capacity was the most promising assay and the compounds 25, 26 and 28 provided better inhibition values than all the standards. Further binding mode and affinity studies performed by molecular docking and molecular dynamics simulations. Accordingly, the compound 19 is the most plausible candidate that can compete with galantamine (GNT), a common pharmaceutics targeting both cholinesterase enzymes.

GC-MS analysis and Mitochondrial Functionality Potential of the Fruits of<i>Tetrapleura tetraptera</i> By Cupric Reducing Antioxidant Capacity Assay

The use of antioxidants has emerged as a promising therapeutic strategy for the management of mitochondrial dysfunction and other oxidative stress-related degenerative pathologies. Tetrapleura tetraptera is a well-known tree and its fruit is applied traditionally as spice and in the preparation of remedies for different ailments. In this study, the gas chromatography-mass spectrometry (GC-MS) analysis and mitochondrial functionality potential of T. tetraptera fruits were investigated. GC-MS was used to detect compounds in then-hexane and ethanol extracts of T. tetraptera fruits. Cupric reducing antioxidant capacity (CUPRAC) assay was used to evaluate the mitochondrial functionality potential of the ethanol extract. GC-MS analysis revealed the presence of six compounds in then-hexane extract of T. tetraptera fruits. These compounds were detected in trace quantities, the most abundant being 2,3-dimethyl-3-buten-2-ol (0.04%). The compounds: cis-vaccenic acid (35.37%), n-hexadecanoic acid (28.09%), 6-octadecenoic acid (25.21%), and octadecanoic acid (11.33%) were identified in the ethanol extract of the fruits. Consequently, the ethanol extract was subjected to CUPRAC assay. The ethanol extract exhibited a concentration-dependent high cupric reducing capacity, returning CUPRAC values in the range of 0.090 to 0.403 at the concentration of 10 – 80 μg/ml. This activity was comparable to that of the positive control, naringenin, which showed CUPRAC values of 0.059 – 0.378 at the same concentrations. These results indicate that T. tetraptera fruits possess good antioxidant property as evaluated by other related antioxidant assays. This could be attributed to a synergistic effect of the phytochemical constituents. Hence consumption of T. tetraptera fruits could be beneficial for the prevention of mitochondrial dysfunction and other oxidative stress-related degenerative disorders.
 Keywords: Tetrapleura tetraptera, mitochondrial dysfunction, degenerative disorders, CUPRAC, GC-MS, Nigeria

Influence of honey addition on the bioaccessibility of phenolic contents and antioxidant capacities of different coffee types

This study was designed to assess the effect of honey addition to the antioxidant capacity and in vitro bioaccessibility of phenolic content of both brewed and soluble coffee. Floral and pine honey were used in the assay. The antioxidant capacities of the samples were evaluated with three different methods: DPPH radical scavenging activity, cupric reducing capacity and total antioxidant capacity tests. In order to measure the antioxidant metabolites of the samples, total phenolic and flavonoid contents were appraised. In vitro gastrointestinal digestion simulation procedure was conducted to mimic the physiochemical and biochemical factors of the gastrointestinal tract. During the digestion process, components in the food matrix are exposed to significant structural changes and certain amount of them are effectively absorbed and reach the circulation. To that end, the importance of studies concerning the simulated gastrointestinal digestion increases. The results of this study revealed that honey addition to coffee samples induced increases in antioxidant capacities, total phenolic and flavonoid contents.

Ramalina capitata (Ach.) Nyl. acetone extract: HPLC analysis, genotoxicity, cholinesterase, antioxidant and antibacterial activity.

In the present investigation, effects of Ramalina capitata acetone extract on micronucleus distribution on human lymphocytes, on cholinesterase activity and antioxidant activity (by the CUPRAC method) were examined, for the first time as well as its HPLC profile. Additionally, total phenolic compounds (TPC), antioxidant properties (estimated via DPPH, ABTS and TRP assays) and antibacterial activity were determined. The predominant phenolic compounds in this extract were evernic, everninic and obtusatic acids. Acetone extract of R. capitata at concentration of 2 μg mL-1 decreased a frequency of micronuclei (MN) for 14.8 %. The extract reduces the concentration of DPPH and ABTS radicals for 21.2 and 36.1 % (respectively). Values for total reducing power (TRP) and cupric reducing capacity (CUPRAC) were 0.4624 ± 0.1064 μg ascorbic acid equivalents (AAE) per mg of dry extract, and 6.1176 ± 0.2964 μg Trolox equivalents (TE) per mg of dry extract, respectively. The total phenol content was 670.6376 ± 66.554 μg galic acid equivalents (GAE) per mg of dry extract. Tested extract at concentration of 2 mg mL-1 exhibited inhibition effect (5.2 %) on pooled human serum cholinesterase. The antimicrobial assay showed that acetone extract had inhibition effect towards Gram-positive strains. The results of manifested antioxidant activity, reducing the number of micronuclei in human lymphocytes, and antibacterial activity recommends R. capitata extract for further in vivo studies.

Determination of the phenolic content, profile, and antioxidant activity of seeds from nine tree peony (Paeonia section Moutan DC.) species native to China

As an important resource of functional food, the seeds of tree peony are rich in phenolic compounds, which are associated with antioxidant activity. However, so far there has not been systematic study on phenolic compositions and antioxidant activity of the seeds from wild tree peony species. The aim of this study was to determine the phenolic content, antioxidant compounds and antioxidant activity of seeds from nine tree peony species native to China. Among the seed samples, Paeonia rockii had the highest total flavonoid content, strongest DPPH and ABTS radical scavenging activities, and strongest cupric reducing capacity; P. decomposita subsp. rotundiloba had the highest total phenolic and flavanol contents, as well as the strongest hydroxyl radical scavenging activity. Sixteen individual phenolic compounds were quantitatively measured, with (+)-catechin being the most abundant component. The content of the phenolic compounds luteolin, paeonol, and the total flavonoid content were significantly correlated with four antioxidant activities. Hierarchical cluster analysis showed that P. rockii and P. decomposita subsp. rotundiloba could be clustered in a group having a high phenolic content and strong antioxidant activity. These results suggest P. rockii and P. decomposita subsp. rotundiloba are the most promising candidates as useful sources of natural antioxidants.

Biological activities of Umbilicaria crustulosa (Ach.) frey acetone extract

This paper reports for the first time the effect of an acetone extract of Umbilicaria crustulosa on the micronucleus distribution of human lymphocytes, and on the cholinesterase activity and antioxidant activity by the cupric ion reducing antioxidant capacity (CUPRAC) method. Additionally, the total phenolic compounds (TPC) and the antioxidant properties were estimated via DPPH, ABTS and TRP assays. Moreover, the antibacterial activity against two Gram-positive and three Gram-negative bacteria were determined. Acetone extract of U. crustulosa at concentration of 1 and 2 ?g mL-1 decreased a frequency of micronuclei (MN) by 10.8 and 16.8 %, respectively, acting more or slightly less than the synthetic protector amifostine (AMF, WR-2721, 11.4 %, at concentration of 1 ?g mL-1). The tested extract did not inhibit cholinesterase activity nor did it exhibit activity toward the examined bacteria. The extract reduced the concentration of DPPH and ABTS radicals by 88.7 and 96.2 %, respectively. Values for total reducing power (TRP) and cupric reducing capacity (CUPRAC) were 0.6197?0.0166 ?g ascorbic acid equivalents (AAE) per mg of dry extract, and 19.7641?1.6546 ?g trolox equivalents (TE) per mg of dry extract, respectively. The total phenol content was 350.4188 ?14.587 ?g gallic acid equivalents (GAE) per mg of dry extract. The results of the present study showed that U. crustulosa acetone extract is a promising candidate for in vivo experiments considering its antioxidant activity and protective effect on human lymphocytes.

Effect of in vitro gastrointestinal digestion on the bioavailability of phenolic components and the antioxidant potentials of some Turkish fruit wines

This study was designed to evaluate the effects of in vitro gastrointestinal simulation method on the antioxidant potentials and phenolic profile of some Turkish fruit wines and to compare the results with a Turkish red wine prepared from native grape varieties (Papazkarası). For this purpose, blueberry, black mulberry and cherry wines were studied since they are widely consumed in Turkey. Papazkarası wine was chosen due to the lack of studies regarding this type of wine. Antioxidant potentials of samples were measured with four different methods: DPPH radical-scavenging activity, H2O2-scavenging activity, cupric reducing capacity and total antioxidant capacity assays. The phenolic profiles of samples were evaluated by the determination of total phenolic content and HPLC-DAD analysis of seven different molecules. The results of this study provided information not only the effect of gastrointestinal digestion on parameters mentioned above, but also the bioaccessibility about the phenolic compounds found in these four different wine samples.

Antioxidant, Brine Shrimp Lethality and Antimicrobial Activities of Methanol and Ethyl-Acetate Extracts of Citrus macroptera Montr. Fruit Using In vitro Assay Models

Aims: To study and evaluate In vitro antioxidant, brine shrimp lethality and antimicrobial activities of both methanol and ethyl-acetate extracts of Citrus macroptera Montr. Fruit (Family-Rutaceae).Study Design: In vitro antioxidant, brine shrimp lethality and antimicrobial activities.Place and Duration of Study: Department of Pharmacy, Jahangirnagar University, Savar, Dhaka-1342. The study was carried out from November 2013 to January 2014.Methodology: In vitro antioxidant activities of the extracts were studied using DPPH radical scavenging assay, NO scavenging assay, total phenol, total flavonoid content, total antioxidant capacity, total tannin content, lipid peroxidation by TBA, lipid peroxidation in human erythrocyte cell, reducing power capacity and cupric reducing capacity assays. Lethality bioassay was performed on Artemia salina Leach nauplii. Antimicrobial activity was investigated by disc diffusion technique.Results: Methanol extract showed better activity than ethyl acetate extract in DPPH, NO, lipid peroxidation by TBA, reducing power capacity assay, total phenol, total flavonoid and total antioxidant capacity assays while ethyl –acetate extract showed more potency than methanol extract in total tannin content, cupric reducing capacity and lipid peroxidation in human erythrocyte assays. In brine shrimp bioassay both extracts showed promising lethal activity but methanol extract was found to be more potent than ethyl acetate extract (χ2=39.874, P<0.0001). In disc diffusion technique among six bacterial species, ethyl acetate extract showed broad spectrum antimicrobial activity against two gram positive Bacillus sublitis and Staphylococcus aureus and one gram negative Escherichia coli. Conclusion: The results demonstrate that methanol and ethyl-acetate extracts of C. macroptera fruit can be used as potential antioxidant, cytotoxic and antimicrobial agents. That is why extensive researches are necessary to search for active principles responsible for these activities.

English

To uncover the antioxidant and free radical scavenging activity, five different extracts ofTerminalia arjuna&nbsp;bark were examined. In the present study, the free radical scavenging potential of five extracts of the bark of&nbsp;Terminalia arjuna&nbsp;was assessed by measuring its capability for scavenging 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical, hydrogen peroxide radical, nitric oxide radicals (NO), as well as its ability in reducing power capacity assessment, cupric reducing antioxidant capacity, using appropriate assay systems compared to natural and synthetic antioxidants. Total antioxidant capacity, phenolic and flavonoid contents were determined spectrophotometrically. In DPPH free radical scavenging activity,&nbsp;the highest IC50&nbsp;value was showed by methanol extract with a value of6.34 &micro;g/ml&nbsp;followed by ethanol and petroleum ether having value of&nbsp;7.76 and 25.63,respectively,&nbsp;as opposed to that of the scavenging effects of ascorbic acid and butylated hydroxytoluene (BHT) of&nbsp;5.698 and 8.816,&nbsp;respectively. Methanol extract showed highest activity having&nbsp;IC50&nbsp;value of 14.436 and 25.184 &mu;g/ml in hydrogen peroxide&nbsp;and nitric oxide scavenging assay, respectively. All the five fractions showed good reducing power and cupric reducing capacity with increasing concentration again taking methanol extract to the top position. The methanol extract yielded 817.488 &plusmn; 8.108 mg/g gallic acid equivalent phenolic content and 199.122 &plusmn; 8.282 mg/g Quercetin equivalent flavonoid content that was highest among five extracts. Methanol extract of&nbsp;T. arjuna&nbsp;was found to possess the highest total antioxidant capacity (415.925 &plusmn; 2.291) followed by ethanol (377.675 &plusmn; 1.889) mg/g Ascorbic Acid Equivalent, respectively. A linear correlation appeared between the total antioxidant capacity and the total phenolic contents of the extracts with good correlation coefficient (R2&nbsp;= 0.891). n-Hexane and chloroform extract showed least activity in all the measures. The results obtained beacon that&nbsp;T. arjuna&nbsp;is a potential source of antioxidants and thus could prevent many radical related diseases. &nbsp; Key words:&nbsp;Terminalia arjuna,&nbsp;n-hexane extract, petroleum ether extract, chloroform extract, ethanol extract, methanol extract,&nbsp;in vitro&nbsp;antioxidant activity.

Investigation of cytotoxicity and in-vitro antioxidant activity of Asparagus racemosus root extract

This attempt is made to address the phytoconstituents, free radical scavenging activity and brine shrimp lethality bioassay of five different extracts of Asparagus racemosus roots. Preliminary phytochemical examination of the crude extracts of Asparagus racemosus root disclosed the existence of different sort of chemical groups such as flavonoids, tannin, saponin, alkaloids, carbohydrate. The root displayed significant DPPH free radical scavenging activity with highest IC50 value showed by ethanol extract with a value of 78.15 µg/ml followed by methanol and petroleum ether having value of 106.44 µg/ml and 273.31 µg/ml respectively as opposed to that of the scavenging effects of ascorbic acid and BHT of 5.698 µg/ml and 8.816 µg/ml respectively. The highest reducing power was showed by ethanol extract followed by methanol and petroleum ether as opposed to that of the reducing potential of ascorbic acid and BHT. The fractions represented good cupric reducing capacity with increasing concentration taking ethanol extract in the top position. The ethanol extract yielded 108.78±2.77 mg/gm gallic acid equivalent phenolic content and methanol sub-fraction yielded 164.77±1.73 mg/gm quercetin equivalent flavonoid content that was highest among five extracts. Ethanol extract of Asparagus racemosus was found to possess the highest total antioxidant capacity (639.925±64.78) mg/gm followed by methanol (616.92±53.88) mg/gm and petroleum ether (469.17±52.95) mg/gm ascorbic acid equivalent respectively. In brine shrimp lethality bioassay, LC50 values for ethanol, methanol, petroleum ether, n-hexane and chloroform were found to be 0.674 µg/ml, 0.719 µg/ml, 0.984 µg/ml, 2.157µg/ml and 1.514 µg/ml respectively. N-hexane and chloroform extract showed least activity in all the measures. The results suggest that Asparagus racemosus is a valuable source of antioxidant and has significant cytotoxic activity hence could eliminate many diseases related to free radical.DOI: http://dx.doi.org/10.3329/icpj.v1i9.11615 International Current Pharmaceutical Journal 2012, 1(9): 250-257

Varietal differences among the phenolic profiles and antioxidant properties of four cultivars of spine grape (Vitis davidii Foex) in Chongyi County (China)

Spine grape (Vitis davidii Foex) is an important wild plant species in South China. To provide sufficient experimental evidence for the strong antioxidant activity of spine grapes, four cultivars from Chongyi County, China, including three red varieties (Junzi #1, Junzi #2, and Liantang) and one white variety (Baiyu) were evaluated. The Junzi #1 had the highest phenolic content (total phenolic, flavonoids, flavanols, and anthocyanins) and the strongest antioxidant capacity (DPPH radical-scavenging capacity, cupric-reducing capacity and hydroxyl radical-scavenging activity) among the four varieties. HPLC analysis of spine grapes revealed that the (+)-catechin was the most abundant phenolics and the hydroxycinnamic acids were the major phenolic acids in the four varieties. Hierarchical cluster analysis showed that the Junzi #1 belongs to the group with high phenolic content and strong antioxidant power. The results suggest the Junzi #1 has the best health promoting properties, and the higher utilization value and potential for development.