Biological activities of ethyl acetate extract of different parts of Hyssopus angustifolius

Context: Hyssopus angustifolius M. Bieb. (Lamiaceae) is one of the most important medicinal plants in Iranian traditional medicine for the treatment of lung inflammation, laryngitis and cough relief. Much attention has been paid to this medicinal plant because of its traditional uses.

Objective: The present study examined the antioxidant and antihemolytic activities of ethyl acetate extract of stems, leaf and flowers of Hyssopus angustifolius.

Materials and methods: Antioxidant activity of extracts was evaluated by employing six different models, i.e., DPPH, nitric oxide and hydrogen peroxide scavenging, metal chelating and reducing power activities and hemoglobin-induced linoleic acid system. Also, antihemolytic activity was evaluated against hydrogen peroxide-induced hemolysis.

Results: Flowers extract showed the better activity than leaf and stems extracts in DPPH radical scavenging activity (IC₅₀ was 275.4?±?7.6 μg mL^?1). Leaf, stems and flowers extracts showed good nitric oxide scavenging activity (IC₅₀ were 376.6?±?11.4 µg mL^?1 for flowers, 297.6?±?9.6 μg mL^?1 µg mL^?1 for leaves and 837.8?±?19.2 µg mL^?1 for stems). The leaf extract exhibited better hydrogen peroxide scavenging and Fe²⁺ chelating activity than stems and flowers extracts. In hemoglobin-induced linoleic acid system, all of the extracts exhibited very good activity. Also, extracts show weak reducing power activity. The ethyl acetate extract of leaf showed better antihemolytic activity than the flower and stems (IC₅₀ was 94.0?±?2.4 μg mL^?1).

Discussion and conclusion: These findings give a scientific basis to the traditional usage of Hyssopus angustifolius, also showing its potential as rich sources of natural antioxidant compounds.     

Potential of rare actinomycetes in the production of metabolites against multiple oxidant agents

Context: Actinobacteria are a precious source of novel bioactive metabolites with potential pharmaceutical applications.

Objectives: Representatives of 11 genera of rare Actinobacteria were selected for the evaluation of antioxidant activity.

Material and methods: Fermentation broths of the Actinobacteria were extracted and dosage of 10 to 2000?µg/mL were applied for in vitro antioxidant-related bioassays. Cytotoxicity was assessed at the concentration of 2.5–20?µg/mL.

Results: In the DPPH scavenging activity, 15 out of 52 extracts showed 17.0–26.8% activity in quantitative evaluation. Metabolites of five prominent antioxidant producing strains protected the DNA (pUC19) against UV-induced photolyzed H₂O₂-oxidative degradation. The potent antioxidant extracts inhibited two oxidative enzymes of xanthine oxidase in the range of 17.5–45.2% (three extracts had IC₅₀ less than allopurinol) and lipoxygenase in the range of 36–55% (all five extracts had IC₅₀ values less than daidzein). All these extracts could also protect eythrocytes from iron-induced hemolysis with ED₅₀ values in a range of 0.014–1.25?mg/mL. Growth restoration of the yeast cells lacking the sod1 gene was observed by the antioxidant metabolite of Saccharothrix ecbatanensis UTMC 537 at the concentration of 1?mg/mL.

Conclusions: The presence of nonidentical metabolites might be responsible for antioxidant and enzyme inhibitory activities of S. ecbatanensis, newly described actinobacterium in family Pseudonocardiaceae. The scavenging of the free electrons, protection of DNA and model yeast cells against oxidative stress, in addition to the inhibition of the oxidating enzymes are the main mechanisms of the antioxidant effect of the introduced resource in this study.     

Pharmacological evaluation for anti-asthmatic and anti-inflammatory potential of Woodfordia fruticosa flower extracts

Context: Woodfordia fruticosa Kurz. (Lythraceae) flowers are ethnopharmacologically acclaimed in the Indian medicinal system to treat asthma.

Objective: To evaluate W. fruticosa flower extracts for anti-asthmatic effect.

Materials and methods: Ethyl acetate, acetone, methanol, and hydro-alcohol extracts of W. fruticosa flowers were obtained successively and standardized. Ability of extracts to stabilize free radicals and compound-48/80-induced mast cell degranulation was evaluated. In vitro anti-inflammatory potential of extracts at 100 and 200?µg/ml by membrane stabilization and in vivo inhibition of rat paw edema up to 5?h (100 and 200?mg/ml; p.o.) was evaluated. In vitro bronchorelaxant effect was examined against histamine- and acetylcholine (1?µg/ml; independently)-induced guinea pig tracheal contraction. Extracts were evaluated for bronchoprotection (in vivo) ability against 0.1% histamine- and 2% acetylcholine-induced bronchospasm in guinea pigs at 100 and 200?mg/ml; p.o.

Results: Standardization studies revealed that the methanol extract exhibited highest polyphenolic (62.66 GAE), and flavonoid (6.32 RE) content and HPLC fingerprinting confirmed the presence of gallic acid (R_t 1.383). IC₅₀ values for DPPH scavenging and metal chelation by the methanol extract were 40.42 and 31.50?µg/ml. Methanol and ethyl acetate extracts at 100?µg/ml exhibited 06.52 and 07.12% of histamine release. Methanol, ethyl acetate, and hydro alcohol extracts at 200?mg/kg demonstrated 32.73, 29.83, 26.75% and 32.46, 9.38, 26.75% inhibition of egg albumin and carrageenan-induced inflammation, respectively. Methanol extract exhibited 100% bronchorelaxation and 48.83% bronchoprotection.

Conclusion: Woodfordia fruticosa flower (WFF) extracts exhibited anti-asthmatic effect by demonstrating bronchoprotection, bronchorelaxation, anti-inflammatory, antioxidant, and mast cell stabilization ability.     

Antioxidant activity of different parts of Tetrataenium lasiopetalum

Abstract

Context: In Iranian traditional medicine, different species of the genus Tetrataenium are used as antiseptic, spice and food additives.

Objective: The present study examined the possible antioxidant effects of hydro-alcoholic extracts of different parts of Tetrataenium lasiopetalum (Boiss.) Manden (Apiaceae).

Materials and methods: Laminas, stems, petioles, fruits, peduncles and flowers of T. lasiopetalum were collected, dried and then extracted by ethanol and water (70:30). Antioxidant activities of extracts were examined by employing different in vitro assays, i.e., 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, metal chelating, reducing power activities and hemoglobin-induced linoleic acid system. Also, total phenolic and flavonoid contents of the extracts were evaluated.

Results: Hydro-alcoholic extract of T. lasiopetalum flower showed the highest activity in scavenging of DPPH (IC₅₀?=?170?±?7?μg/mL). In metal chelating assay, lamina extract possesses a better iron ion chelating activity than other extracts (230?±?10?μg/mL). Lamina hydro-alcoholic extract demonstrated better activity in reducing the power and hemoglobin-induced linoleic acid system than other parts of T. lasiopetalum.

Discussion and conclusion: These results showed the antioxidant activity of different parts of T. lasiopetalum based on its usage in traditional medicine.     

Comparison of xanthine oxidase‐inhibiting and free radical‐scavenging activities between plant adaptogens of Eleutherococcus senticosus and Rhodiola rosea

The present study employed 2,2‐diphenyl‐l‐picrylhydrazyl (DPPH) radical‐scavenging and xanthine–xanthine oxidase (XO) assays to compare the antioxidant capacity between two plant adaptogens, Eleutherococcus senticosus (Araliaceae) and Rhodiola rosea (Crassulaceae). The IC₅₀ value for XO activity for Rhodiola was 355.4 µg/ml, while that for Eleutherococcus was >1,000 µg/ml. Eleutherococcus inhibited DPPH generation by 58.3±2.8% at 1,000 µg/ml, whereas Rhodiola inhibited DPPH radical by 91.1±2.6% at the same concentration. The results suggested that Rhodiola inhibited not only XO but also served as a potent radical scavenger. Rhodiola has potential as a natural source of antioxidants. Drug Dev Res 71:249–252, 2010. © 2010 Wiley‐Liss, Inc.     

Evaluation of the antimutagenic,antigenotoxic, and antioxidant activities of Eriobotrya japonica leaves

Abstract

Context: The leaves of Eriobotrya japonica (Thunb.) Lindl. (Rosaceae) are used in traditional medicine to treat inflammatory diseases. However, information about the antigenotoxic and antioxidant properties of its leaves remains to be elucidated.

Objective: The objective of this work was to evaluate the mutagenic/antimutagenic, genotoxic/antigenotoxic, and antioxidant potentials of aqueous and total oligomers flavonoid (TOF) extracts from E. japonica.

Materials and methods: The mutagenic/antimutagenic and genotoxic/antigenotoxic potentials of extracts (50, 250, and 500?µg/plate) were evaluated, respectively, by the Ames test with 48?h incubation and the SOS chromotest test with 2?h incubation. The antioxidant capacity of these extracts (ranging from 50 to 700?µg/mL) was tested using xanthine/xanthine oxidase and the deoxyribose assays.

Results: Eriobotrya japonica extracts showed neither mutagenic nor genotoxic effect. The highest protective effect against methyl methanesulfonate and 2-aminoanthracene was obtained in the presence of aqueous extract, with IC₅₀ values of 80 and 140?µg/plate, respectively, against S. typhimurium TA104. Moreover, this extract (500?µg/plate) was also able to reduce significantly the genotoxicity induced by nitrofurantoin and aflatoxin B1 with IC₅₀ values of 140 and 240?µg/assay, respectively. Likewise, aqueous and TOF extracts inhibited xanthine oxidase and superoxide anion formation with IC₅₀ values ranging from 45 to 95 and from 70 to 90?µg/mL, respectively. However, TOF extract is more efficient in inhibiting hydroxyl radical and chelating iron ion with IC₅₀ values of 140 and 400?µg/mL, respectively, when compared with the aqueous extract.

Conclusion: Eriobotrya japonica prevents the genotoxicity of some carcinogenic substances probably thanks to its antioxidant capacities.     

Antioxidant and anti-inflammatory activities of Pittocaulon species from México

Context: Stems and leaves of Pittocaulon spp. (Asteraceae) are used in Mexican traditional medicine as an anti-inflammatory substance and for the treatment of skin injuries.

Objective: This study evaluated the antioxidant activity of methanol (MeOH) and dichloromethane (DC) extracts of five Pittocaulon species.

Materials and methods: DC and MeOH extracts from flowers, roots, and stems of Pittocaulon praecox (Cav.) H. Rob. & Brettell, P. bombycophole (Bullock) H. Rob. & Brettell, P. filare (Mc Vaugh) H. Rob. & Brettell, P. velatum (Greenm.) Rob. & Brettell and P. hintonii H. Rob. & Brettell.

Result and Discussion: In the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, the flower extracts obtained with MeOH were the most active with IC₅₀ values ranging from 51.83?±?4.08 to 154.19?±?8.39 ppm. In the thiobarbituric acid reactive substances (TBARS) model, the best activity was shown by DC extracts of roots with IC₅₀ values ranging from 55.54?±?1.28 to 160.82?±?5.37 ppm. The MeOH extract of flowers of P. bombycophole had the highest IC₅₀ value in both DPPH (51.83?±?4.08 ppm) and TBARS (39.78?±?1.97 ppm). The samples with the best values in the antioxidant activity assays were evaluated in the anti-inflammatory tests. The DC root extract of P. velatum at a dose of 1?mg/ear produced the greatest reduction (84.96%) of the 2-O-tetradecanoylphorbol-13-acetate (TPA)-induced mouse ear edema. This extract also reduced the activity of the enzyme myeloperoxidase (MPO) (73.65%) at the same dose. In contrast, DC root extract of this species did not show significant inhibition of the increase in paw edema induced by carrageenan at the doses tested (100?mg/kg).

Conclusion: These results support the traditional use of these plants as anti-inflammatory. DC extracts of P. velatum and MeOH extracts of P. bombycophole may be a potential resource of natural anti-inflammatory and antioxidant compounds, respectively. Additional studies must be done to identify the compounds responsible of the activity on these plants and to establish the mechanism of action.     

Antioxidant,antihyperuricemic and xanthine oxidase inhibitory activities of Hyoscyamus reticulatus

Context:?Xanthine oxidase (XO) is a key enzyme in the pathophysiological homeostasis of hyperuricemia. It catalyzes the oxidation of hypoxanthine to xanthine and then to uric acid, the reaction involves the formation of free radical intermediates and superoxide byproducts.

Objectives:?This study was undertaken to investigate the antioxidant, antihyperuricemic, and xanthine oxidase inhibitory potentials of Hyoscyamus reticulatus L. (Solanaceae) extract.

Materials and methods:?The antioxidant potency was measured using the ABTS^?+ scavenging capacity system, which includes Trolox as a standard. The xanthine oxidase inhibitory activity of the extract was quantitated in vitro by measuring the decline in the catalytic rate of xanthine oxidase following incubations with the plant extracts and using xanthine as a substrate. The hypouricemic potential of the extract was evaluated using an in vivo model for hyperuricemia. We tested three different doses of the extract and allopurinol was used as standard antihyperuricemic positive control.

Results:?H. reticulatus aqueous extract exhibited significant antioxidant scavenging properties (533.26 μmol TE/g dry extract weight) and inhibitory effect on xanthine oxidase activity (IC₅₀ 12.8 μg/mL). Furthermore, oral administration of the aqueous extract significantly reduced serum urate levels in oxonate-induced hyperuricemic mice in a dose-dependent manner.

Discussion and conclusion:?Our results suggest that the aqueous extract of H. reticulatus aerial parts might have great potential as an antioxidant and a hypouricemic agent. Our lab is currently identifying the active compounds in the extract to which the biological activities could be attributed.     

In vitro antioxidant activity of Bombax malabaricum flower extracts

Context: Bombax malabaricum DC. (Bombacaceae) is a traditional Chinese herbal medicine used for the treatment of inflammatory conditions, diarrhea, fever, chronic inflammation, catarrhal affection, and as a diuretic. However, little information is available about its antioxidative activity.

Objective: Water, 50% ethanol, and 80% acetone extracts from flowers of B. malabaricum were investigated for their in vitro antioxidant activity in this article for the first time. Then the relationships between antioxidant activity measured by different methods and total phenolic content (TPC) and total flavonoid content (TFC) were established.

Materials and methods: The antioxidant activities of extracts from B. malabaricum flower were investigated including 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity, oxygen radical absorbance capacity (ORAC), reducing power, and inhibition on phosphatidylcholine liposome peroxidation.

Results: Results showed that all the extracts possessed remarkable antioxidant capacity compared with ascorbic or gallic acids. Total antioxidant activities evaluated by ORAC assay of different extracts ranged from 700.03 to 1482.46 μmol Trolox equivalents/g. The highest TPC of 130.38?mg gallic acid equivalents (GAE)/g was observed in 80% acetone extract, whereas the lowest TPC of 57.09?mg GAE/g was obtained in the water extract. Furthermore, TFC exhibited significant (P?<?0.05) positive correlations with DPPH radical-scavenging activity, ORAC, and reducing power.

Discussion and conclusion: These findings demonstrate that the flowers of B. malabaricum have excellent antioxidant activities and thus might be a potential source of natural antioxidants.     

Geographic origin influences the phenolic composition and antioxidant potential of wild Crataegus monogyna from Spain

Context: Crataegus monogyna Jacq L. (Lind.) (Rosaceae) is used in folk medicine as a sedative, aerial parts being rich in polyphenols with antioxidant ability.

Objectives: To study the variation in polyphenolic composition and antioxidant ability of spontaneous samples of C. monogyna in order to assess the relationship among these variables.

Materials and methods: Aerial parts of C. monogyna were collected from nine different locations in central Spain and extracted with methanol after drying. Total polyphenols were determined by the Folin-Ciocalteu method using gallic acid (GA) as standard. Sixteen polyphenolic compounds (11 flavonoids and 5 phenolic acids) were identified and quantified by reversed-phase HPLC in one single analysis. The antioxidant ability was evaluated by the oxygen radical absorbance capacity (ORAC) and the free radical scavenging activity (DPPH) methods. Linear correlation analysis was used to explore the relationships between the studied variables.

Results: Total polyphenol content ranged between 117.729?±?0.011 and 204.286?±?0.015?mg GAE/g extract, depending on the geographic origin. No relationship was found between total polyphenols and antioxidant ability by the ORAC or DPPH methods. Chromatographic analysis yielded lower amounts of polyphenols (23.3–143.26?mg/kg), as only flavonoids and phenolic acids were quantified. All the samples exhibited antioxidant activity between 1.32?±?0.08 and 2.76?±?0.007?μmol Trolox equivalents/mg and IC₅₀ from 0.82?±?0.10 to 3.76?±?0.67?μg/mL.

Conclusion: A statistically significant relationship between flavonoids and phenolic acids content and the antioxidant potential obtained by the ORAC method for C. monogyna samples was proven.     

Employing photoacoustic spectroscopy in the evaluation of the skin permeation profile of emulsion containing antioxidant phenolic-rich extract of Melochia arenosa

Context: Oxidative stress is an important factor modulating skin alterations. Melochia arenosa Benth. (Malvaceae) is a Brazilian plant with antimicrobial activity and antioxidant potential.

Objective: The objective of this study is to develop a topical formulation containing antioxidant phenolic-rich extract of M. arenosa and to evaluate its skin permeation profile.

Materials and methods: Response surface methodology was used to maximize the total phenolic (TP) content of the extract and its antioxidant activity was evaluated by 2,2-diphenyl-1-picryl-hydrazyl (DPPH), 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and respiratory burst methods. An emulsion containing 1% optimized extract (OE) was developed and employed photoacoustic spectroscopy (PAS) for the determination of its skin permeation profile. The morphology of the skin was studied in histological sections stained with hematoxylin–eosin.

Results and discussion: The optimum conditions predicted for the major extractive efficiency of the phenolics with 100% ethanol led extraction time 101?h and plant:solvent proportion 1:13.5 (w/v). OE presented TP?=?724.6?±?8.2?mg GAE/g extract and scavenging capacity of DPPH (IC₅₀ value?=?11.43?±?0.14?µg/mL) and ABTS radicals (IC₅₀ value?=?35.42?±?0.48?µg/mL). The production of ROS by neutrophils after stimulation with phorbol miristate acetate was lower when the OE was present in the reaction medium, endorsing its high antioxidant capacity. The data obtained by PAS indicated that the OE present in the emulsion has permeated and was distributed in the whole skin. No histopathological alterations were observed in the histological analysis.

Conclusion: The formulation developed is a promising tool for skin care and could prevent the damage caused by oxidative stress.     

Protection of DNA and erythrocytes from free radical induced oxidative damage by black gram (Vigna mungo L.) husk extract

Antioxidants present in various plant tissues exhibit health benefits by scavenging reactive oxygen species generated under various pathophysiological conditions. In the present study, bioactive compounds from black gram husk were extracted with water and the protection of black gram husk (BGH) extract against oxidative damage in DNA and erythrocytes were studied. BGH extract had total polyphenol content of 59 mg of gallic acid equivalents (GAE). The phenolic acids identified in the extract using RP-HPLC were gallic, protocatechuic, gentisic and ferulic acids. The extract showed good antioxidant properties. The IC₅₀ value for DPPH radical scavenging activity was found to be 3.92 μg of GAE. The BGH extract also showed α-glucosidase inhibition and the IC₅₀ value was found to be 2.78 μg of GAE. The oxidative hemolysis caused by hydrogen peroxide in rat erythrocytes was inhibited by BGH extract in a dose dependent manner. The IC₅₀ values for BGH extract and BHA for hemolysis were 11.5 and 14 μg of GAE, respectively. Morphological changes in erythrocyte membrane caused by hydrogen peroxide were protected by BGH extract. As BGH extract exhibited various antioxidant properties in different systems, it could be used as a functional food or nutraceutical product for health benefits.     

In vitro antioxidant and cytotoxic properties of ethanol extract of Alpinia oxyphylla fruits

Abstract

Context. Alpinia oxyphylla Miquel (Zingiberaceae) is a traditional Chinese herbal medicine widely used for the treatment of intestinal disorders, urosis and diuresis. However, information about antioxidant and cytotoxic properties of its fruits remains to be elucidated.

Objective: The ethanol crude extract (CE) and its fractions [petroleum ether fraction (PF), ethyl acetate fraction (EF), n-butanol fraction (BF) and water fraction (WF) extracted by petroleum ether, ethyl acetate, n-butanol and water, respectively] of A. oxyphylla fruits were investigated for their antioxidant activity and cytotoxicity.

Materials and methods: The total phenolic content (TPC) and antioxidant activity of the extracts were determined by Folin–Ciocalteu reagent, 1,1-diphenyl-2-picrylhydrazyl (DPPH^?), Trolox equivalent antioxidant capacity and reducing power assay. Cytotoxicity of the extracts (0–200?μg/mL) was tested on six human cancer cell lines (breast cancer cell line, cervix carcinoma cell line, lung adenocarcinoma cell line, liver carcinoma cell line, gastric cancer cell line and colon cancer cell line) using the sulforhodamine B assay.

Results: The TPC of extracts varied from 8.2 to 20.3?mg gallic acid equivalents/g dry weight. DPPH radical scavenging effect of extracts decreased in the order of EF?>?BF?>?CE?>?PF?>?WF, with IC₅₀ values ranging from 74.7 to 680.8?μg/mL. 2,2-azo-bis(3-Ethylbenzothiazoline-6-sulfoic acid) diammonium salt scavenging activity ranged from 0.118 to 0.236?mmol Trolox equivalence/mg extract. The extracts exhibited concentration-dependent reducing power, and EF showed the highest reducing ability. A satisfactory correlation (R²?>?0.826) between TPC and antioxidant activity was observed. In addition, EF, PF and CE exhibited potent anticancer effects on six cancer cell lines with IC₅₀ values ranging from 40.1 to 166.3?μg/mL.

Discussion and conclusion: The ethanol extract of A. oxyphylla fruit, especially the EF, was found to possess potent antioxidant and anticancer activities, and thus a great potential for the application in food and drug products.     

Human cancer cell antiproliferative and antioxidant activities of Juglans regia L.

Several studies suggest that regular consumption of nuts, mostly walnuts, may have beneficial effects against oxidative stress mediated diseases such as cardiovascular disease and cancer. Walnuts contain several phenolic compounds which are thought to contribute to their biological properties. The present study reports the total phenolic contents and antioxidant properties of methanolic and petroleum ether extracts obtained from walnut (Juglans regia L.) seed, green husk and leaf. The total phenolic contents were determined by the Folin–Ciocalteu method and the antioxidant activities assessed by the ability to quench the stable free radical 2,2′-diphenyl-1-picrylhydrazyl (DPPH) and to inhibit the 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced oxidative hemolysis of human erythrocytes. Methanolic seed extract presented the highest total phenolic content (116 mg GAE/g of extract) and DPPH scavenging activity (EC₅₀ of 0.143 mg/mL), followed by leaf and green husk. In petroleum ether extracts, antioxidant action was much lower or absent. Under the oxidative action of AAPH, all methanolic extracts significantly protected the erythrocyte membrane from hemolysis in a time- and concentration-dependent manner, although leaf extract inhibitory efficiency was much stronger (IC₅₀ of 0.060 mg/mL) than that observed for green husks and seeds (IC₅₀ of 0.127 and 0.121 mg/mL, respectively). Walnut methanolic extracts were also assayed for their antiproliferative effectiveness using human renal cancer cell lines A-498 and 769-P and the colon cancer cell line Caco-2. All extracts showed concentration-dependent growth inhibition toward human kidney and colon cancer cells. Concerning A-498 renal cancer cells, all extracts exhibited similar growth inhibition activity (IC₅₀ values between 0.226 and 0.291 mg/mL), while for both 769-P renal and Caco-2 colon cancer cells, walnut leaf extract showed a higher antiproliferative efficiency (IC₅₀ values of 0.352 and 0.229 mg/mL, respectively) than green husk or seed extracts. The results obtained herein strongly indicate that walnut tree constitute an excellent source of effective natural antioxidants and chemopreventive agents.     

Antioxidant and antimicrobial activities of ethanol and aqueous extracts from Urtica urens

Context: Urtica urens L. (Urticaceae) is an important and commonly used plant for its medicinal and pharmacological properties.

Objective: We analyzed the antioxidant and antimicrobial activities of the leaves of Urtica urens in ethanol (EtOH) and water (WA) solvents, employing standard analytical methods.

Materials and methods: Polyphenol, flavonoid and tannin content of Urtica urens leaves were determined, after their extraction, using EtOH (70%) and WA extracts as well as the antioxidant (DPPH, ABTS, β-carotene and FRAP) and the antibacterial (via the method of dilution tests) activities of EtOH and WA extracts.

Results: The 70% EtOH of Urtica urens showed the highest values of total phenolic (31.41?mg GAE/g DW), flavonoids (6.81?mg quercetin/g DW), tannin (8.29?mg GAE/g DW) and TEAC (560?mmol Trolox/g DW), compared to the WA. The results of DPPH for EtOH (95.56%) were higher than that of WA (64.56%) at a concentration of 40?mg/L. The extracts displayed a FRAP 106.23 for EtOH and 30.55?μmol Fe(II)/g DW for WA. The results clearly indicated that EtOH was the strongest radical scavenger (IC_50?=_?245.65?±?10.2?μg/mL). Ethanol was the most effective with minimum inhibitory concentration (MIC)?Discussion and conclusion: The results indicate that leaves of Urtica urens could be used as natural antioxidant and antimicrobial agents.     

Extraction and quantification of polyphenols from kinnow (Citrus reticulate L.) peel using ultrasound and maceration techniques

An investigation was carried out to extract polyphenols from the peel of kinnow (Citrus reticulate L.) by maceration and ultrasound-assisted extraction (UAE) techniques. The antioxidant potential of these polyphenols was evaluated using ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and superoxide radical scavenging assays; and their antimicrobial activity was assessed against bacterial strains Staphyloccoccus aureus, Bacillus cereus, and Salmonella typhimurium. The highest extraction yield was obtained through the solvent ethanol at 80% concentration level, whereas UAE was a more efficient technique and yielded comparatively higher polyphenol contents than maceration. Maximum polyphenols were extracted with 80% methanol [32.48 mg gallic acid equivalent (GAE)/g extract] using UAE, whereas minimum phenolics (8.64 mg GAE/g extract) were obtained with 80% ethyl acetate through the maceration technique. Elevated antioxidant activity of kinnow peel extracts was exhibited in three antioxidant assays, where 80% methanolic extracts showed the highest antioxidant activity (27.67 ± 1.11mM/100 g for FRAP) and the highest scavenging activity, 72.83 ± 0.65% and 64.80 ± 0.91% for DPPH and superoxide anion radical assays, respectively. Strong correlations between total polyphenols and antioxidant activity were recorded. Eleven phenolic compounds—including five phenolic acids and six flavonoids—were identified and quantified by high performance liquid chromatography. Ferulic acid and hesperidin were the most abundant compounds whereas caffeic acid was the least abundant phenolic compound in kinnow peel extracts. Maximum inhibition zone was recorded against S. aureus (16.00 ± 0.58 mm) whereas minimum inhibition zone was noted against S. typhimurium (9.00 ± 1.16 mm). It was concluded that kinnow mandarin peels, being a potential source of phenolic compounds with antioxidant and antimicrobial properties, may be used as an ingredient for the preparation of functional foods.     

Evaluation of antiurolithiatic and antioxidant potential of Lepidagathis prostrata: A Pashanbhed plant

Context: Oxidative stress acts as an essential mediator in the pathophysiology of urolithiasis. Lepidagathis prostrata Dalz. (Acanthaceae) is a Pashanbhed plant that is recommended for the management of urolithiasis; however, no scientific validation has been reported.

Objectives: To evaluate the antiurolithiatic and antioxidant potential of L. prostrata.

Materials and methods: Methanol extract (LPM) and fractions; petroleum ether (LPPE), ethyl acetate (LPEA), n-butanol (LPBU) and aqueous (LPAQ) were prepared. In vitro antiurolithiatic activity was evaluated by the capacity to inhibit calcium oxalate (CaOx) nucleation and aggregation at different concentrations of extract/fractions (0.04–3?mg/mL) for 30?min. Total phenol and flavonoid content and antioxidant potential were determined. A validated HPTLC method was performed to quantify lupeol and β-sitosterol.

Results: LPEA exhibited the highest dose-dependent inhibition of CaOx nucleation (IC₅₀: 336.23?±?30.79?µg/mL) and aggregation (IC₅₀: 149.63?±?10.31?µg/mL), which was significantly (p?<?0.05) better than standard Cystone®. The polar LPBU fraction was enriched with phenols (47.34?±?0.19?mg GAE/g) and flavonoids (20.38?±?0.05?mg QE/g), which correlates with its highest antioxidant potential in DPPH, ABTS, nitric oxide scavenging and iron chelating activities (IC₅₀: 1.18–87.34?µg/mL). To our knowledge, this is the first study reporting the presence of lupeol and β-sitosterol in L. prostrata.

Conclusion: The antiurolithiatic activity of L. prostrata is probably mediated through the inhibition of CaOx crystallization. In addition to its free radical scavenging and antioxidant activities, it would act as an excellent agent for the prevention of urolithiasis.     

Effect of gamma irradiation on phenol content,antioxidant activity and biological activity of black maca and red maca extracts (Lepidium meyenii walp)

This study was performed to determine the effects of gamma irradiation on UV spectrum on maca, total content of polyphenols, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activities and in vivo biological activities of red and black maca extracts (Lepidium meyenii).

Adult mice of the strain Swiss aged 3 months and weighing 30–35?g in average were used to determine biological activities. Daily sperm production, effect on testosterone-induced prostate hyperplasia and forced swimming test were used to determine the effect of irradiation on biological activities of maca extracts.

Irradiation did not show differences in UV spectrum but improves the amount of total polyphenols in red maca as well as in black maca extracts. In both cases, black maca extract has more content of polyphenols than red maca extract (p?<?0.01). Gamma irradiation significantly increased the antioxidant capacity (p?<?0.05).

No difference was observed in daily sperm production when irradiated and nonirradiated maca extract were administered to mice (p?>?0.05). Black maca extract but not red maca extract has more swimming endurance capacity in the forced swimming test. Irradiation of black maca extract increased the swimming time to exhaustion (p?<?0.05). This is not observed with red maca extract (p?>?0.05). Testosterone enanthate (TE) increased significantly the ventral prostate weight. Administration of red maca extract in animals treated with TE prevented the increase in prostate weight. Irradiation did not modify effect of red maca extract on prostate weight (p?>?0.05).

In conclusion, irradiation does not alter the biological activities of both black maca and red maca extracts. It prevents the presence of microorganisms in the extracts of black or red maca, but the biological activities were maintained.     

The potential medicinal value of plants from Asteraceae family with antioxidant defense enzymes as biological targets

Abstract

Context: Plants and most of the plant-derived compounds have long been known for their potential pharmaceutical effects. They are well known to play an important role in the treatment of several diseases from diabetes to various types of cancers. Today most of the clinically effective pharmaceuticals are developed from plant-derived ancestors in the history of medicine.

Objective: The aim of this study was to evaluate the free radical scavenging activity and total phenolic and flavonoid contents of methanol, ethanol, and acetone extracts from flowers and leaves of Onopordum acanthium L., Carduus acanthoides L., Cirsium arvense (L.) Scop., and Centaurea solstitialis L., all from the Asteraceae family, for investigating their potential medicinal values of biological targets that are participating in the antioxidant defense system such as catalase (CAT), glutathione S-transferase (GST), and glutathione peroxidase (GPx).

Materials and methods: In this study, free radical scavenging activity and total phenolic and flavonoid contents of the plant samples were assayed by DPPH, Folin–Ciocalteu, and aluminum chloride colorimetric methods. Also, the effects of extracts on CAT, GST, and GPx enzyme activities were investigated.

Results and discussion: The highest phenolic and flavonoid contents were detected in the acetone extract of C. acanthoides flowers, with 90.305?mg GAE/L and 185.43?mg Q/L values, respectively. The highest DPPH radical scavenging was observed with the methanol leaf extracts of C. arvense with an IC₅₀ value of 366?ng/mL. The maximum GPx and GST enzyme inhibition activities were observed with acetone extracts from the flower of C. solstitialis with IC₅₀ values of 79 and 232?ng/mL, respectively.     

Antioxidant activities and molecular mechanisms of the ethanol extracts of Baccharis propolis and Eucalyptus propolis in RAW64.7 cells

Context Numerous studies have reported that propolis possesses strong antioxidant activities. However, their antioxidant molecular mechanisms are unclear.

Objective We utilize ethanol extracts of Chinese propolis (EECP) as a reference to compare ethanol extracts of Eucalyptus propolis (EEEP) with ethanol extracts of Baccharis propolis (EEBGP) based on their antioxidant capacities and underlying molecular mechanisms.

Materials and methods HPLC and chemical analysis are utilized to evaluate compositions and antioxidant activities. ROS-eliminating effects of EEBGP (20–75?μg/mL), EEEP (1.25–3.75?μg/mL) and EECP (1.25–5?μg/mL) are also determined by flow cytometry analysis. Moreover, we compared antioxidant capacities by determining their effects on expressions of antioxidant genes in RAW264.7 cells with qRT-PCR, western blot and confocal microscopy analysis.

Results EEBGP mainly contains chlorogenic acid (8.98?±?0.86?mg/g), kaempferide (11.18?±?8.31?mg/g) and artepillin C (107.70?±?10.86?mg/g), but EEEP contains 10 compositions, whereas EECP contains 17 compositions. Meantime, although EEEP shows DPPH (IC₅₀ 19.55?±?1.28), ABTS (IC₅₀ 20.0?±?0.31) and reducing power (2.70?±?0.08?mmol TE/g) better than EEBGP’s DPPH (IC₅₀ 43.85?±?0.54), ABTS (IC₅₀ 38.2?±?0.33) and reducing power (1.53?±?0.05?mmol TE/g), EEBGP exerts much higher ROS inhibition rate (40%) than EEEP (under 20%). Moreover, EEBGP strengthen antioxidant system by activating p38/p-p38 and Erk/p-Erk kinase via accelerating nucleus translocation of Nrf2. EEEP and EECP improve antioxidant gene expression only via Erk/p-Erk kinase-Nrf2 signalling pathway.

Discussion and conclusion EEBGP and EEEP exert antioxidant activities via different molecular mechanisms, which may depend on chemical compositions.