Phytochemical and antioxidant properties of some Cassia species

In this study, the antioxidant activity of aqueous and ethanol extracts of four plants from the genus Cassia were evaluated by various antioxidant assays, including ferric reducing antioxidant power (FRAP), DPPH free radical scavenging, metal chelating activity, phosphomolybdenum reducing power, hydrogen peroxide radical scavenging, hydroxyl radical scavenging, deoxyribose degradation and β-carotene bleaching assay. The various antioxidant activities were compared to standard antioxidant such as ascorbic acid. All the extracts showed antioxidant activity in the tested methods. Among the four species, Cassia auriculata has been found to possess highest activity in most of the tested models. In addition to the antioxidant activity, the total phenolics and flavonoids were measured in the extracts. The ethanolic extract exhibited highest phenolics and flavonoid contents and had also shown potent antioxidant activity in comparison to the aqueous extracts. The possible antioxidant mechanism of the ethanol extract can be due to its hydrogen or electron donating and direct free radical scavenging properties. Hence, the ethanol extract represents a source of potential antioxidants that could be used in pharmaceutical industries.     

Free radical scavenging, antimicrobial and immunomodulatory activities of Orthosiphon stamineus

Orthosiphon stamineus is considered an important traditional folk medicine. In this study ethanol and aqueous extracts of O. stamineus were evaluated in vitro for their antioxidant, antimicrobial as well as for their immunomodulatory properties on human peripheral blood mononuclear cells (PBMCs). The DPPH radical scavenging method was used for the determination of antioxidant activity, while the antibacterial efficacy was investigated by both disc diffusion method and Minimum Inhibitory Concentration (MIC) against four bacterial strains (Gram-positive and Gram-negative). Furthermore, the immunomodulatory potential of the extracts was investigated through the MTT assay. Aqueous extract of O. stamineus exhibited significant free radical scavenging activity with IC?? 50 9.6 μg/mL, whereas the IC?? for the ethanol extract was 21.4 μg/mL. The best antimicrobial activity was shown by the aqueous extract of O. stamineus against Staphylococcus aureus, with inhibition zone of 10.5 mm and MIC value 1.56 mg/mL. Moreover, the results observed from the MTT assay showed that both plant extracts stimulated the PBMCs proliferation in vitro in a concentration-dependent manner, but the aqueous extract has remarkable activity against PBMCs. These findings indicate that O. stamineus showed high antioxidant activity and may be considered as an immunomodulatory agent.     

A Study on the In Vitro Antioxidant Activity of Juniper (Juniperus communis L.) Fruit Extracts

Abstract

This study aimed at evaluating the in vitro antioxidant activity of water and ethanol extracts of juniper (Juniperus communis L., Family Cupressaceae) fruit. The antioxidant properties of both Juniper extracts were studied using different antioxidant assays, including reducing power, free radical scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging, and metal chelating activities. Both the water and the ethanol extracts exhibited strong total antioxidant activity. The concentrations of 20, 40, and 60 µg/mL of water and ethanol extracts of juniper fruit showed 75%, 88%, 93%, 73%, 84%, and 92% inhibition on peroxidation of linoleic acid emulsion, respectively. On the other hand, 60 µg/mL of standard antioxidant such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), and α‐tocopherol exhibited 96, 96, and 61 inhibitions on peroxidation of linoleic acid emulsion, respectively. However, both extracts of juniper had effective reducing power, free radical scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging, and metal chelating activities at these same concentrations (20, 40, and 60 µg/mL). Those various antioxidant activities were compared to BHA, BHT, and α‐tocopherol as standard antioxidants. In addition, total phenolic compounds in both aqueous and ethanolic juniper extracts were determined as gallic acid equivalents. Accordingly, these results indicate that juniper has in vitro antioxidant properties and these may be major reasons for the inhibition of lipid peroxidation properties.     

Antioxidant capacity and phenolic content of Caesalpinia pyramidalis Tul. and Sapium glandulosum (L.) Morong from Northeastern Brazil

The aims of this study were to quantify the phenolic content and evaluate the antioxidant potential of extracts from the bark and leaves of C. pyramidalis and S. glandulosum. The total phenolic content (TPC) and total tannin content (TTC) were determined using the Folin-Ciocalteu method, and the total flavonoids content (TFC) was measured via complexation with aluminum chloride. The antioxidant activity was evaluated with DPPH (2.2-diphenyl-1-picrylhydrazyl) and FIC (ferrous ion chelating) assays. The TPC ranged between 135.55 ± 9.85 and 459.79 ± 11.65 tannic acid equivalents (TAE) in mg/g material (mg TAE/g). The leaves of both species contained high levels of tannins and flavonoids. The crude ethanol extracts (CEE) from the bark of C. pyramidalis showed high antioxidant activity when compared to ascorbic acid and rutin, whereas the CEE from the leaves was more efficient in chelating ferrous ions. C. pyramidalis had very high phenolic content and anti-radical activity, which indicates a need for further studies aimed at the purification and identification of compounds responsible for the antioxidant activity.     

Evaluation of influence of selected metal cations on antioxidant activity of extracts from savory (<Emphasis Type="Italic">Satureja hortensis</Emphasis>)

The analysis of the antioxidant activity of ethanol, methanol, acetone and aqueous extracts from the dried leaves and stems of savory is presented. The culinary herb used to study was procured from ecological agriculture in the Podlasie region of Poland. The antioxidant properties of extracts were calculated using the 1,1-diphenyl-2-picryl-hydrazyl radical (DPPH) and ferric-reducing antioxidant power (FRAP) (expressed as mg Trolox per g of dry mass) methods. In addition, the total phenolics contents of the herbal extracts were determined using the Folin-Ciocalteu reagent. The antioxidative activity of extracts as dependent on the type of solvent used for the extraction and concentration of savory in extracts is discussed. The influence of the concentration of different metal ion solutions on the anti-radicals’ properties of savory extracts was evaluated.     

Chemical composition and antioxidant activity of Borago officinalis L. leaf extract growing in Algeria

The aqueous and hydroalcoholic extracts of borage (Borago officinalis) leaves from Annaba region (Algeria) were preliminary analyzed for their phenolic profile (total phenolics, total flavonoids, total flavonols, total tannins and total anthocyanins). These extracts were evaluated for their antioxidant properties by different methods such as DPPH radical scavenging, test NBT and total antioxidant activity. The two extracts have exhibited a high antiradical capacity. Indeed, the ethanolic extract showed the lower IC50 values and the highest amount of phenolics (94.09 ± 1.72 mg gallic acid/g dry extract). Using LC-MS/MS analysis, it was possible to identify phenolic acids, flavonoids, sterol and for the first time oleuropein was identified in the aqueous extract of the plant. The obtained results have demonstrated that phenolic compounds are the major contributor to the antioxidant activity of plants.     

Phenolic enriched extract of Baccharis trimera presents anti-inflammatory and antioxidant activities

Baccharis trimera is a plant popularly used as a tea and to treat gastrointestinal diseases and inflammatory processes as well. The total phenolic content was determined and the antioxidant and anti-inflammatory activities of six extracts (dichloromethane, ethyl acetate, butanol, aqueous, saponin and phenolic) from B. trimera were evaluated. Using carrageenan-induced pleurisy as a model of acute inflammation, the phenolic extract at 15 mg/kg decreased significantly the analyzed parameters when compared to the carrageenan group ( p < 0.05), thus showing potential anti-inflammatory activity. The total phenolic content and antioxidant activity were evaluated by the Folin-Ciocalteau and DPPH methods, respectively. Phenolic and ethyl acetate extracts presented higher antioxidant activity ( p < 0.05) than ascorbic acid. The phenolic extract also showed the highest antioxidant potential in relation to the other extracts, thus suggesting that the antioxidant and anti-inflammatory activities were due to the presence of phenolic compounds.     

In vitro antioxidant activity of the water and ethanol extracts of Forsythia koreana flowers

The antioxidant activities of the water and ethanol extracts of F. koreana flowers were evaluated using DPPH, superoxide anion (?O(-2)), and nitric oxide (?NO) radical scavenging activity assays. The SC(50) values of the water extract of F. koreana on DPPH, ?O(-2) and ?NO were 48.39, 24.36 and 100.21 μg mL(-1), respectively. The SC(50) values of the ethanol extract of F. koreana on the aforesaid free radicals were 57.50, 49.00 and 146.08 μg mL(-1), respectively. Further, the total phenolic contents of both extracts were determined and expressed as milligram gallic acid equivalent (GAE) per gram of extract. The water extract exhibited a higher phenolic content (113.78 mg GAE?g(-1)), while the ethanol extract showed 94.53?mg GAE?g(-1). Our findings demonstrate that the water and ethanol extracts of F. koreana flowers might be potential natural sources of antioxidative additives for use in the food and other allied industries.     

Selective Extraction of Sinapic Acid Derivatives from Mustard Seed Meal by Acting on pH: Toward a High Antioxidant Activity Rich Extract

The aim of this paper is to study the effect of the pH on the extraction of sinapic acid and its derivatives from mustard seed meal. Solutions of acidic pH (pH 2), basic pH (pH 12) and distilled water (uncontrolled pH ~ 4.5) were tested at different percentages of ethanol. The maximum extraction yield for sinapic acid (13.22 µmol/g of dry matter (DM)) was obtained with a buffered aqueous solution at pH 12. For ethyl sinapate, the maximum extraction yield reached 9.81 µmol/g _DM with 70% ethanol/buffered aqueous solution at pH 12. The maximum extraction yield of sinapine (15.73 µmol/g _DM) was achieved with 70% ethanol/buffered aqueous solution at pH 2. The antioxidant activity of each extract was assessed by DPPH assay; the results indicated that the extracts obtained at pH 12 and at low ethanol percentages (<50%) exhibit a higher antioxidant activity than extracts obtained at acidic conditions. Maximum antioxidant activity was reached at pH 12 with buffer solution (11.37 mg of Trolox Equivalent/g _DM), which confirms that sinapic acid-rich fractions exhibit a higher antioxidant activity. Thus, to obtain rich antioxidant extracts, it is suggested to promote the presence of sinapic acid in the extracts.     

Phenolic content and antioxidant properties of soybean (Glycine max (L.) Merr.) seeds

The contents and antioxidant ability of various classes of phenolic compounds present in the seeds of twenty soybean hybrids were evaluated. Total phenolics, tannins and proanthocyanidins were determined spectrophotometrically, after extraction of seeds with 70% aqueous acetone. In addition, the flavonoid contents were determined. The antioxidant activity of aqueous acetone extracts was evaluated by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity assay. The highest contents of total phenolics were found in Serbian cultivar 1511 and Chinese cultivar LN92-7369, which also displayed the highest total antioxidant activity. Conversely, genotypes poor in phenolics also showed low levels of DPPH-radical scavenging activity. The results suggested that besides protein and oil contents, the phenolic contents should be also considered as an important characteristic feature of soybean seeds, and as a potential selection criterion for antioxidant activity in soybean.     

Antioxidant activity and total phenolic content of aqueous and methanolic extracts of Jordanian plants: an ICBG project

As part of an International Cooperative Biodiversity Groups (ICBG) program to study Jordan's biodiversity, the relative levels of antioxidant activity and the total phenolic content of aqueous and methanolic extracts of a total of 95 plant species, all of Jordanian origin and those collected at random, have been measured. The total phenolic content of aqueous and methanolic extracts of the investigated plant species ranged from 4.4 to 78.3 mg and from 2.1 to 52.8 mg gallic acid equivalents g(-1) dry weight, respectively, while the total antioxidant capacity ranged from 20.0 to 916.7 and from 15.1 to 915.6 micromol Trolox equivalents g(-1) dry weight, respectively. Based on this collection, approximately 5% of assayed plants showed high levels of antioxidant activity. There was a significant linear correlation between antioxidant activity and total phenolic content for aqueous and methanolic extracts, suggesting that phenolic compounds were the predominant antioxidant components in the investigated plant species. Interestingly, a few of the collected plants had high-antioxidant activity yet "low" phenolic content includes Ceratonia siliqua and Viscum cruciatum. These plants may serve as sources of antioxidants with new chemotypes.     

Analgesic and anti-inflammatory properties of Thespesia populnea leaf extracts

Analgesic and anti-inflammatory activities of the aqueous and ethanol extracts of Thespesia populnea Soland. ex. Correa (Malvaceae) leaves were evaluated in animal models. Orally-administered aqueous and ethanol extracts (100, 200 and 400?mg?kg?1 bw) showed significant analgesic activity in chemical-, mechanical- and thermally-induced pain test models in mice. The extracts also reduced paw oedema induced by carrageenan in rats. The results obtained in this study suggest that Thespesia populnea extracts have analgesic and anti-inflammatory properties.     

Antioxidant activities of extracts and fractions from Eupatorium lindleyanum DC

The antioxidant activities of water extract (WE), ethanol extract (EE), residue water extract (RWE) and petroleum ether (PF), ethyl acetate (EF), n-BuOH (BF) and water (WF) fractions of the ethanol extract from Eupatorium Lindley DC were investigated for the first time. Total phenolics content, DPPH radical scavenging activities, superoxide radical scavenging activities, total reduction capability, and ferrous ions chelating activities were determined for all the extracts and fractions. The results showed that all the extracts and fractions exhibited antioxidant activities with different magnitudes of potency. Among all the samples, WE and RWE exhibited the best antioxidant capacities, the BF also exhibited high antioxidant abilities in all tests except for the metal chelating activity, while the other extracts and fractions were relatively weak antioxidants. The BF had the highest total phenolics contents in all extracts and fractions, and the WE and RWE were found to be rich in tannins. Furthermore, the content of total phenolics showed good correlation with DPPH radical scavenging activity, superoxide anion radical scavenging activity, and the reducing power. Phenolic composition of all the extracts and fractions was identified and quantified by HPLC. The results indicate that the extracts of E. Lindley DC might be a useful potential source of natural antioxidant ingredients.     

Antioxidant, antimicrobial properties and phenolics of different solvent extracts from bark, leaves and seeds of Pongamia pinnata (L.) Pierre

This study appraises the antioxidant and antimicrobial attributes of various solvent extracts (absolute methanol, aqueous methanol, absolute ethanol, aqueous ethanol, absolute acetone, aqueous acetone, and deionized water) from bark, leaves and seeds of Pongamia pinnata (L.) Pierre. Maximum extraction yield of antioxidant components from bark (16.31%), leaves (11.42%) and seeds (21.51%) of P. pinnata was obtained using aqueous methanol (20:80). Of the extracts tested, the bark extract, obtained with aqueous methanol, exhibited greater levels of total phenolics [6.94 g GAE/100 g dry weight (DW)], total flavonoids (3.44 g CE/100 g DW), inhibition of linoleic acid peroxidation (69.23%) and DPPH radical scavenging activity (IC(50) value, 3.21 μg/mL), followed by leaves and seeds extracts. Bark extract tested against a set of bacterial and fungal strains also revealed the strongest antimicrobial activity with the largest inhibition zone and lowest minimum inhibitory concentration (MIC). HPLC analysis of aqueous methanol extracts from bark, leaves and seeds indicated the presence of protocatechuic, ellagic, ferulic, gallic, gentisic, 4-hydroxybenzoic and 4-hydroxycinnamic acids in bark (1.50-6.70 mg/100 g DW); sorbic, ferulic, gallic, salicylic and p-coumaric acids in leaves (1.18-4.71 mg/100 g DW); vanillic, gallic and tannic acids in seeds (0.52-0.65 mg/100 g DW) as the main phenolic acids. The present investigation concludes that the tested parts of P. pinnata, in particular the bark, have strong potential for the isolation of antioxidant and antimicrobial agents for functional food and pharmaceutical uses.     

Acute toxicity evaluation, antibacterial, antioxidant and immunomodulatory effects of Melastoma malabathricum

Melastoma malabathricum (MM) is a well-known plant in Malaysian traditional medicine, locally known as senduduk. Its ethanol and aqueous extracts have been used in the present investigation to study the immunomodulatory role on human peripheral blood mononuclear cell (PBMC), and the DPPH, ABTS and FRAP free radical scavenging activities were also measured. Total flavonoids and total phenolic contents were assayed and the antibacterial effect was tested against four species of bacteria; two Gram-positive (Staphylococcus aureus and Streptococcus agalactiae) and two Gram-negative (Escherichia coli and Klebsilla pneumonia). The tests were carried out using the disc diffusion, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) methods. Moreover, the acute toxicity was evaluated in vivo on the ethanol extract of MM to establish its safety when administered orally. In our results, both extracts of MM showed abilities to scavenge DPPH and ABTS free radicals, IC(50) values: (11.599 ± 0.84, 10.573 ± 0.58 μmol/L) and (62.657 ± 0.78, 63.939 ± 0.48 μmol/L) for ethanol and aqueous extracts respectively. Indeed the ethanol extract evidenced high phenolic content (384.33 ± 0.005 mg/g), flavonoids contents (85.8 ± 0.009 mg/g) and ferric reducing antioxidant power (33,590 ± 0.038 mmol/g), with high activity against S. aureus and S. agalactiae (11 ± 0.3 and 12 ± 0.6 mm inhibition zones). Likewise, the percentage of peripheral blood mononuclear cells (PBMC) viability was increased in response to MM, IC(50) values (1.781 ± 1.2 and 6.545 ± 0.93 μg/mL) for ethanol and aqueous extracts, respectively. In addition, our results showed that the MM extract is safe even at a high dose of 5,000 mg/kg and has no oral toxicity. These findings suggest the excellent medicinal bioactivity of MM and explain the popularity of this plant in the folk medicine as a remedy for different illnesses.     

In vitro biological activities and fatty acid profiles of Pistacia terebinthus fruits and Pistacia khinjuk seeds

This study reports in vitro anticholinesterase, antioxidant and antimicrobial effects of the n-hexane, dichloromethane, ethanol and ethanol–water extracts prepared from Pistacia terebinthus L. fruits and Pistacia khinjuk Stocks seeds as well as their total phenolic and flavonoid contents, and fatty acid compositions. Ethanol and ethanol–water extracts of both species exhibited higher anticholinesterase activity than galanthamine. Among ABTS, DPPH and CUPRAC assays, the highest antioxidant capacity of the extracts was found in the last one. P. terebinthus ethanol extract being rich in flavonoid content showed the best cupric reducing effect. All extracts possessed no antimicrobial activity. The main fatty acid in P. terebinthus fruits (52.52%) and P. khinjuk seeds (59.44%) was found to be oleic acid. Our results indicate that P. terebinthus fruits and P. khinjuk seeds could be a good source of anticholinesterase compounds, and could be phytochemically investigated.     

Determination of phenolic compounds,in vitro antioxidant activity and characterization of secondary metabolites in different parts of Passiflora cincinnata by HPLC-DAD-MS/MS analysis

Abstract

Ethanol extracts of different parts of Passiflora cincinnata were obtained by maceration. The total phenolic and flavonoid contents were evaluated. The antioxidant activities were determined by β-carotene-linoleic acid bleaching test, 2,2-diphenyl-1-picrylhydrazil (DPPH), and 2,2’-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging. The crude ethanol stem extract showed the highest amount of total polyphenols (45.53?mg gallic acid equivalent/g) while the highest total flavonoid contents (1.42?mg of quercetin equivalent/g) were observed in the leaf extract. The lowest IC₅₀ (25.65?μg/ml) by the DPPH method was observed for the stem extract. The ABTS method showed a significant antioxidant activity for all investigated extracts. The secondary metabolite composition of ethanol extracts was assessed by HPLC-DAD-MS/MS analysis, leading to the identification of fourteen secondary metabolites in P. cincinnata extracts. These results showed the potentiality of this species as a source of phenolic compounds and antioxidants.     

Effects of different extraction methods and conditions on the phenolic composition of mate tea extracts

A simple and rapid HPLC method for determination of chlorogenic acid (5-O-caffeoylquinic acid) in mate tea extracts was developed and validated. The chromatography used isocratic elution with a mobile phase of aqueous 1.5% acetic acid-methanol (85:15, v/v). The flow rate was 0.8 mL/min and detection by UV at 325 nm. The method showed good selectivity, accuracy, repeatability and robustness, with detection limit of 0.26 mg/L and recovery of 97.76%. The developed method was applied for the determination of chlorogenic acid in mate tea extracts obtained by ethanol extraction and liquid carbon dioxide extraction with ethanol as co-solvent. Different ethanol concentrations were used (40, 50 and 60%, v/v) and liquid CO? extraction was performed at different pressures (50 and 100 bar) and constant temperature (27 ± 1 °C). Significant influence of extraction methods, conditions and solvent polarity on chlorogenic acid content, antioxidant activity and total phenolic and flavonoid content of mate tea extracts was established. The most efficient extraction solvent was liquid CO? with aqueous ethanol (40%) as co-solvent using an extraction pressure of 100 bar.     

Antioxidant and antiproliferative activities of Helleborus odorus Waldst. & Kit, H. multifidus Vis. and H. hercegovinus Martinis

This study was undertaken in order to evaluate possible antioxidative and antiproliferative activities of three Helleborus taxa. The dry leaves and roots of three Helleborus taxa were extracted with ethanol and water. A phytochemical evaluation of the selected extracts was performed using spectrophotometric methods and a 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity assay was used for measuring the antioxidative activity of extracts. The antiproliferative activity of the three Helleborus taxa was studied using Burkitt's lymphoma B cells (BJAB) cell lines. The phytochemical evaluation showed that the leaves contain high levels of total phenolic and flavonoid content. Results from the DPPH assay indicated that the activity of the ethanol and water extracts of the leaves was higher than that of positive control (thymol). Extracts from the roots of H. odorus also displayed higher antioxidant activity than the positive probe, while H. mulifidus and H. hercegovinus root extracts were less effective. A statistically significant correlation between total phenolic content and antioxidative properties indicates that these compounds contribute to the antioxidant activity. The highest percentage of cell growth inhibition was observed when testing the water root extracts of H. multifidus (50.14%) and H. hercegovinus (49.04%). In contrast, the water leaf extract of H. hercegovinus exhibited the lowest inhibition of cell growth (8.59%), although it showed strong antioxidant activity.     

Chemical Composition,Antioxidant and Cytoprotective Potentials of Carica papaya Leaf Extracts: A Comparison of Supercritical Fluid and Conventional Extraction Methods

The leaves of Carica papaya (CP) are rich in natural antioxidants. Carica papaya has traditionally been used to treat various ailments, including skin diseases. This study aims to decipher the antioxidant effects and phytochemical content of different CP leaf extracts (CPEs) obtained using supercritical carbon dioxide (scCO₂) and conventional extraction methods. The antioxidant activities of CPEs were evaluated by cell-free (1,1-diphenyl-2-picryl-hydrazyl (DPPH) and ferric-reduced antioxidative power (FRAP)) and cell-based (H₂O₂) assay. Both C. papaya leaf scCO₂ extract with 5% ethanol (CPSCE) and C. papaya leaf scCO₂ extract (CPSC) exhibited stronger DPPH radical scavenging activity than conventional extracts. In the FRAP assay, two hydrophilic extracts (C. papaya leaf ethanol extract (CPEE) and C. papaya freeze-dried leaf juice (CPFD)) showed relatively stronger reducing power compared to lipophilic extracts. Cell-based assays showed that CPFD significantly protected skin fibroblasts from H₂O₂-induced oxidative stress in both pre-and post-treatment. CPEE protected skin fibroblasts from oxidative stress in a dose-dependent manner while CPSCE significantly triggered the fibroblast recovery after treatment with H₂O₂. GC-MS analysis indicated that CPSCE had the highest α-tocopherol and squalene contents. By contrast, both CP hydrophilic extracts (CPEE and CPFD) had a higher total phenolic content (TPC) and rutin content than the lipophilic extracts. Overall, CPEs extracted using green and conventional extraction methods showed antioxidative potential in both cell-based and cell-free assays due to their lipophilic and hydrophilic antioxidants, respectively.