Characterization of Protein Hydrolysates from Fish Discards and By-Products from the North-West Spain Fishing Fleet as Potential Sources of Bioactive Peptides.

Fish discards and by-products can be transformed into high value-added products such as fish protein hydrolysates (FPH) containing bioactive peptides. Protein hydrolysates were prepared from different parts (whole fish, skin and head) of several discarded species of the North-West Spain fishing fleet using Alcalase. All hydrolysates had moisture and ash contents lower than 10% and 15%, respectively. The fat content of FPH varied between 1.5% and 9.4% and had high protein content (69.8-76.6%). The amino acids profiles of FPH are quite similar and the most abundant amino acids were glutamic and aspartic acids. All FPH exhibited antioxidant activity and those obtained from Atlantic horse mackerel heads presented the highest 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, reducing power and Cu2+ chelating activity. On the other hand, hydrolysates from gurnard heads showed the highest ABTS radical scavenging activity and Fe2+ chelating activity. In what concerns the α-amylase inhibitory activity, the IC50 values recorded for FPH ranged between 5.70 and 84.37 mg/mL for blue whiting heads and whole Atlantic horse mackerel, respectively. α-Glucosidase inhibitory activity of FPH was relatively low but all FPH had high Angiotensin Converting Enzyme (ACE) inhibitory activity. Considering the biological activities, these FPH are potential natural additives for functional foods or nutraceuticals.

Antioxidant activity of an ethnobotanically important plant Quisqualis indica Linn.

The antioxidant potential of leaf, stem, root and flower extracts of Quisqualis indica Linn. was assessed to verify its ethnopharmacological importance. Both polar and non-polar solvents like n-hexane, chloroform, ethanol and distilled water were used to obtain crude extracts. The chloroform extract of leaves showed the maximum %age yield, i.e. 27.3% while the n-hexane extract of stem showed the minimum yield, i.e. 0.2%. Five activities including DPPH free radical scavenging activity, ABTS+ assay, Total flavonoid components (TFC), Total phenolic components (TPC) and Metal chelating Assay (MC) were employed to evaluate the antioxidant activity of the plant. The ethanol extract of inflorescence of the plant displayed most elevated DPPH potential, i.e. 452.11%. Aqueous extract of root had highest value of TEAC i.e., 7.4515 mmol. The aqueous extract of flower displayed the highest level of phenolic contents with the value of 35 in terms of GAE mg/mL. On the other hand, the chloroform extract had the highest % bound iron value of 128 and the aqueous extract of flower showed a high concentration of Flavonoids having the value 347.65mg/l of Quercetin. It has been inferred that all parts of Quisqualis indica L. possess good antioxidant potential. Differents parts showed different antioxidant potentials hence they can be used as curative agents against human and animal ailments.

Isolation and characterization of iron chelators from turmeric (Curcuma longa): selective metal binding by curcuminoids.

Iron overload disorders may be treated by chelation therapy. This study describes a novel method for isolating iron chelators from complex mixtures including plant extracts. We demonstrate the one-step isolation of curcuminoids from turmeric, the medicinal food spice derived from Curcuma longa. The method uses iron-nitrilotriacetic acid (NTA)-agarose, to which curcumin binds rapidly, specifically, and reversibly. Curcumin, demethoxycurcumin, and bisdemethoxycurcumin each bound iron-NTA-agarose with comparable affinities and a stoichiometry near 1. Analyses of binding efficiencies and purity demonstrated that curcuminoids comprise the primary iron binding compounds recovered from a crude turmeric extract. Competition of curcuminoid binding to the iron resin was used to characterize the metal binding site on curcumin and to detect iron binding by added chelators. Curcumin-Iron-NTA-agarose binding was inhibited by other metals with relative potency: (>90% inhibition) Cu2+ ~ Al3+ > Zn2+ ≥ Ca2+ ~ Mg2+ ~ Mn2+ (<20% inhibition). Binding was also inhibited by pharmaceutical iron chelators (desferoxamine or EDTA) or by higher concentrations of weak iron chelators (citrate or silibinin). Investigation of the physiological effects of iron binding by curcumin revealed that curcumin uptake by cultured cells was reduced >80% by addition of iron to the media; uptake was completely restored by desferoxamine. Ranking of metals by relative potencies for blocking curcumin uptake agreed with their relative potencies in blocking curcumin binding to iron-NTA-agarose. We conclude that curcumin can selectively bind toxic metals including iron in a physiological setting, and propose inhibition of curcumin binding to iron-NTA-agarose for iron chelator screening.

Phytochemical Profile and Biological Activities of Helianthemum canum l. baumg. from Turkey.

In the current study, antioxidant, antibacterial activities, and the phenolic compositions of extracts from Helianthemum canum L. Baumg. (Apiaceae) aerial parts were investigated for the first time. The H. canum was extracted with 70% methanol (HCMeOH) and water (HCW). Both extracts were determined by total phenolic contents (3 mg/ml), flavonoids (1.5 mg/ml), flavonols (1.5 mg/ml), qualitative-quantitative compositions, iron (II) chelation activities (0.1 - 5 mg/ml), free radical scavenging activities (DPPH• : 0.01 - 0.6 mg/ml and ABTS+• : 0.125 - 0.5 mg/ml) and the effect upon inhibition of ß-carotene/linoleic acid co-oxidation (1 mg/ml). The peroxidation level was also determined using the thiobarbituric acid method (0.01 - 1.5 mg/ml). The results of the activity tests given as IC50 values were estimated from non-linear algorithm and compared with standards. Antibacterial activities of extracts and standards were evaluated against Gram-negative and -positive ten standard strains using disc diffusion and broth microdilution methods. The MIC results (312.5 - 2500 µg/ml) against tested microorganisms varied from 625 to 2500 µg/ml. In HPLC analysis, 3,5-dihydroxybenzoic acid was found as the main substance in both extracts. These results showed that HCMeOH was richer in phenolic compounds (284.13 ± 0.30 mg GAE/g extract) from HCW (244.55 ± 0.35 mg GAE/g extract). In conclusion, H. canum extracts showed in vitro antibacterial and antioxidant activities.

Isolation, Characterization and Bioactivities of an Extracellular Polysaccharide Produced from Streptomyces sp. MOE6.

A Streptomyces strain was isolated from soil and the sequence of 1471 nucleotides of its 16S rDNA showed 99% identity to Streptomyces sp. HV10. This newly isolated Streptomyces strain produced an extracellular polysaccharide (EPS) composed mainly of glucose and mannose in a ratio of 1:4.1, as was characterized by Fourier transform infrared spectroscopy (FTIR), HPLC and ¹H-NMR. The antioxidant activities of the partially purified MOE6-EPS were determined by measuring the hydroxyl free radical scavenging activity and the scavenging of 2,2-diphenyl-2-picryl-hydrazyl (DPPH) radicals. In addition, the partially purified MOE6-EPS showed high ferrous ion (Fe2+) chelation activity which is another antioxidant activity. Interestingly, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays that were colorimetric assays for NAD(P)H-dependent cellular oxidoreductases and a proxy of the number of viable cells, showed that the partially purified MOE6-EPS inhibited the proliferation of the human breast cancer cells (MDA-MB-231). The scratch wound assay showed that MOE6-EPS reduced the migration of mouse breast cancer cells (4T1). This study reports the production of EPS from Streptomyces species with promising antioxidant, metal chelating and mammalian cell inhibitory activities.

Aqueous extract of Securidaca longipendunculata Oliv. and Olax subscropioidea inhibits key enzymes (acetylcholinesterase and butyrylcholinesterase) linked with Alzheimer's disease in vitro.

CONTEXT: Plants have historically been used to treat neurodegerative diseases which include Alzheimer's disease. OBJECTIVE: This study investigated the antioxidant properties and inhibitory effect of aqueous extracts of Securidaca longipendunculata root and Olax subscropioidea leaf on the cholinergic system in rat brain in vitro. MATERIALS AND METHODS: Aqueous extracts (1:20 w/v) of S. longipendunculata root and O. subscropioidea leaf was prepared and the ability of the extract to inhibit the activities of acetylcholinesterase and butyrylcholinesterase was evaluated as well as antioxidants as typified by 2,2-azino-bis-(3-ethylbenthiazoline-6-sulphonic acid (ABTS•) radical scavenging ability and Fe chelation spectophotometrically. RESULTS: ABTS• radical scavenging ability showed that S. longipendunculata (0.075 Mmol TEAC/100 g) had a higher scavenging ability than O. subscropioidea (0.07 Mmol TEAC/100 g). Also, the Fe2+ chelating ability of both extracts revealed that S. longipendunculata (IC50 = 105.57 g/mL) had a significantly (p < 0.05) higher Fe2+ chelating ability than O. subscropioidea (IC50 = 255.84 g/mL). Extracts of S. longipendunculata and O. subscropioidea inhibited acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities. However, S. longipendunculata (IC50 = 108.02 g/mL) has the higher AChE inhibitory activity than O. subscropioidea (IC50 = 110.35 g/mL). Also, both extracts inhibit BChE activity in vitro but S. longipendunculata (IC50 = 82.55 g/mL) had a higher BChE inhibitory activity than O. subscropioidea (IC50 = 108.44 g/mL). DISCUSSION AND CONCLUSIONS: The mechanism by which S. longipendunculata root and O. subscropioidea leaf perform their anti-Alzheimer's disease activity may be by their inhibition on the key enzymes linked to this disease.

Protective activity of Hertia cheirifolia extracts against DNA damage, lipid peroxidation and protein oxidation.

CONTEXT: Hertia cheirifolia L. (Asteraceae), a perennial shrub widely distributed in Northern Africa, is traditionally used to treat inflammatory disorders. OBJECTIVE: The protective effect of methanol (Met E) and aqueous (Aq E) extracts of Hertia cheirifolia against DNA, lipid and protein oxidation was investigated. MATERIALS AND METHODS: Different concentrations (50-1000 µg/mL) of Hertia cheirifolia aerial part extracts were examined against DNA, lipid and protein oxidation induced by H2O2 + UV, FeSO4, and Fe3+/H2O2-ascorbic acid, respectively. The DPPH•, metal ion chelating, reducing power and ß-carotene bleaching tests were conducted. RESULTS: Both extracts were rich in polyphenols, flavonoids and tannins, and were able to scavenge DPPH• with IC50 values of 138 and 197 µg/mL, respectively. At 300 µg/mL, Aq E exerted stronger chelating effect (99%) than Met E (69%). However, Met E reducing power (IC50 = 61 µg/mL) was more than that of Aq E (IC50 = 193 µg/mL). Both extracts protected from ß-carotene bleaching by 74% and 94%, respectively, and inhibited linoleic acid peroxidation. The inhibitory activity of Aq E extract (64%) was twice more than that of Met E (32%). Interestingly, both extracts protected DNA against the cleavage by about 96-98%. At 1 mg/mL, Met E and Aq E restored protein band intensity by 94-99%. CONCLUSIONS: Hertia cheirifolia exhibits potent antioxidant activity and protects biomolecules against oxidative damage; hence, it may serve as potential source of natural antioxidant for pharmaceutical applications and food preservation. This is the first report on the protective activity of this plant against biomolecule oxidation.

Antioxidant activity of different extracts from the aerial part of Moringa peregrina (Forssk.) Fiori, from Jordan.

The antioxidant activities of methanol (M), ethyl acetate (E) and hexane (H) extracts from leaves (L) and seeds (S) of Moringa (Moringa peregrina) were evaluated using different model systems in vitro. Free radical scavenging activities were assessed by measuring the scavenging activities of leaves and seeds different polar extracts separately using ABTS, Hydroxyl (OH) and DPPH radicals. Effect of extracts on ferrous ions chelating ability and total antioxidant capacity were also investigated for each extract. In addition, total phenolics, flavonoids and flavonols content of Moringa leaves and seeds extracts were determined. The leaves methanol (LM) extract showed significantly the highest DPPH radical scavenging activity (IC50value of 5.3±0.2µ/ml), followed by leaves ethylacetate extract (LE) and seeds methanolic extract (SM) with IC50 values of 7.1±0.2 and 7.2±0.4µ/ml, respectively. LE extract showed the highest ABTS radical scavenging activity with IC50value of 49.1±2.7µ/ml, followed by LM extract with IC50value of 61.2±1.2 µ/ml, whereas the highest hydroxyl radical (OH.) inhibition activity was found for LM and SM extracts with IC50 values of 76.9±0.8 and 77.5±1.2µ/ml, respectively. The total antioxidant activity was the highest in LM, LE and SM extracts (294.3, 244.5 and 231.6µ ascorbic acid equivalent for 1mg extract, respectively). LM, LE and SM extracts at concentration of 100µ/ml showed the highest chelating activity against ferrous ions (98.4, 91.1 and 90.7%, respectively). All Moringa leaves and seeds extracts showed pronounced antioxidant activities in a dose dependent manner and the effects depend strongly on the solvent used for extraction. The results showed that extracts of both leaves and seeds of Moringa exhibit antioxidant potential suggesting that M. peregrina is a promising plant.

Phytochemical screening, GC-MS analysis and in vitro antioxidant activity of pollen of Centella asiatica (Linn) urban a traditional medicinal plant.

In the present study the crude extracts of pollen of Centella asiatica (Linn.) Urban were explored for their antioxidant potential using Ferric Reducing Power, Metal Chelating Activity and Trolox Equivalent Antioxidant Capacity assays. In crude extracts of pollen antioxidant components were initially extracted in methanol and further fractionated in solvents of different polarity, such as n-Hexane, Chloroform, Ethyl Acetate and Water exhibited reasonable antioxidant activity. The extract was found to contain large amounts of phenolic and flavonoid contents ranged from 143-1155 mg/l of gallic acid equivalent (GAE) and 911-2488 mg/l of quercetin (QE) respectively. Moreover, Super oxide Anion Radical Scavenging Activity and GS-MS analysis were also carried out.

Production of the natural iron chelator deferriferrichrysin from Aspergillus oryzae and evaluation as a novel food-grade antioxidant.

BACKGROUND: Deferriferrichrysin (Dfcy) is a siderophore found in foods fermented by Aspergillus oryzae and is a promising candidate for an antioxidant food additive because of its high binding constant toward iron. However, the Dfcy concentration is typically low in foods and cultures. RESULTS: We optimised culture conditions to improve Dfcy production to 2800 mg L(-1) from 22.5 mg L(-1) under typical conditions. Then, we evaluated the potential of Dfcy as a food additive by measuring its safety, stability, and antioxidant activity. Dfcy was sufficiently stable that over 90% remained after pasteurisation at 63 °C for 30 min at pH 3-11, or after sterilisation at 120 °C for 4 min at pH 4-6. Dfcy showed high antioxidant activity in an oil-in-water model, where inhibition of lipid oxidation was measured by peroxide value (PV) and thiobarbituric acid reactive substances (TBARS) assays. Dfcy decreased PV and TBARS by 83% and 75%, respectively. Antioxidant activity of Dfcy was equal to or higher than that of the synthetic chelator EDTA. CONCLUSION: Our study provides the first practical method for production of Dfcy. Dfcy can be a novel food-grade antioxidant and the first natural alternative to the synthesised iron chelator EDTA. © 2015 Society of Chemical Industry.

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 ß-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 ß-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.

Compounds from Sedum caeruleum with antioxidant, anticholinesterase, and antibacterial activities.

CONTEXT: This is the first study on the phytochemistry, antioxidant, anticholinesterase, and antibacterial activities of Sedum caeruleum L. (Crassulaceae). OBJECTIVE: The objective of this study is to isolate the secondary metabolites and determine the antioxidant, anticholinesterase, and antibacterial activities of S. caeruleum. MATERIALS AND METHODS: Six compounds (1-6) were isolated from the extracts of S. caeruleum and elucidated using UV, 1D-, 2D-NMR, and MS techniques. Antioxidant activity was investigated using DPPH(•), CUPRAC, and ferrous-ions chelating assays. Anticholinesterase activity was determined against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes using the Ellman method. Antibacterial activity was performed according to disc diffusion and minimum inhibitory concentration (MIC) methods. RESULTS: Isolated compounds were elucidated as ursolic acid (1), daucosterol (2), ß-sitosterol-3-O-ß-D-galactopyranoside (3), apigenin (4), apigetrin (5), and apiin (6). The butanol extract exhibited highest antioxidant activity in all tests (IC50 value: 28.35 ± 1.22 µg/mL in DPPH assay, IC50 value: 40.83 ± 2.24 µg/L in metal chelating activity, and IC50 value: 23.52 ± 0.44 µg/L in CUPRAC), and the highest BChE inhibitory activity (IC50 value: 36.89 ± 0.15 µg/L). Moreover, the chloroform extract mildly inhibited (MIC value: 80 µg/mL) the growth of all the tested bacterial strains. DISCUSSION AND CONCLUSION: Ursolic acid (1), daucosterol (2), ß-sitosterol-3-O-ß-D-galactopyranoside (3), apigenin (4), apigetrin (5), and apiin (6) were isolated from Sedum caeruleum for the first time. In addition, a correlation was observed between antioxidant and anticholinesterase activities of bioactive ingredients of this plant.

TLC profiling, nutritional and pharmacological properties of Siberian ginseng (Eleutherococcus senticosus) cultivated in Poland.

The chemical composition and pharmacological activity of E. senticosus cultivated in Poland were investigated. Studies included the assay of TPC and TFC, 2D-TLC identification of phenolic acids, HPTLC-detection of antioxidants, and antioxidative, antileukemic, anti-MMPs properties of E. senticosus. The ethanolic extracts from the roots, spring leaves, fruits, and the chloroform extract from the roots were tested. The richest in polyphenols are the fresh fruits (57.5 mg/g), while in flavonoids the spring leaves (27.4 mg/g). The antioxidant ability both in extracts and single phenolic constituents were checked out by the measurement of the DPPH radical scavenging activity, iron (II) chelating and lipid peroxidation inhibitory activity. Using HPTLC-DB test eleutherosides B and E1 have been found as the phenolic antioxidants. Thirty six percent of apoptotic cells have been observed in Jurkatt 45 line by the treatment with the chloroform extract from the roots. Only the chloroform extract from the roots and the ethanolic one from the dried fruits have shown the inhibitory activities against MMPs. It is noteworthy, that our studies have been done for the first time, and the plant material has come from another geographical zone (Poland) than native (Asia).

In vitro antioxidant capacity and free radical scavenging evaluation of active metabolite constituents of Newbouldia laevis ethanolic leaf extract.

BACKGROUND: The aim of the present study was to evaluate the in vitro antioxidant and free radical scavenging capacity of bioactive metabolites present in Newbouldia laevis leaf extract. RESULTS: Chromatographic and spectrophotometric methods were used in the study and modified where necessary in the study. Bioactivity of the extract was determined at 10 µg/ml, 50 µg/ml, 100 µg/ml, 200 µg/ml and 400 µg/ml concentrations expressed in % inhibition. The yield of the ethanolic leaf extract of N.laevis was 30.3 g (9.93%). Evaluation of bioactive metabolic constituents gave high levels of ascorbic acid (515.53 ± 12 IU/100 g [25.7 mg/100 g]), vitamin E (26.46 ± 1.08 IU/100 g), saponins (6.2 ± 0.10), alkaloids (2.20 ± 0.03), cardiac glycosides(1.48 ± 0.22), amino acids and steroids (8.01 ± 0.04) measured in mg/100 g dry weight; moderate levels of vitamin A (188.28 ± 6.19 IU/100 g), tannins (0.09 ± 0.30), terpenoids (3.42 ± 0.67); low level of flavonoids (1.01 ± 0.34 mg/100 g) and absence of cyanogenic glycosides, carboxylic acids and aldehydes/ketones. The extracts percentage inhibition of DPPH, hydroxyl radical (OH.), superoxide anion (O2 .-), iron chelating, nitric oxide radical (NO), peroxynitrite (ONOO-), singlet oxygen (1O2), hypochlorous acid (HOCl), lipid peroxidation (LPO) and FRAP showed a concentration-dependent antioxidant activity with no significant difference with the controls. Though, IC50 of the extract showed significant difference only in singlet oxygen (1O2) and iron chelating activity when compared with the controls. CONCLUSIONS: The extract is a potential source of antioxidants/free radical scavengers having important metabolites which maybe linked to its ethno-medicinal use.

Structure and biosynthesis of scabichelin, a novel tris-hydroxamate siderophore produced by the plant pathogen Streptomyces scabies 87.22.

Scabichelin and turgichelin, novel tris-hydroxamate siderophores, were isolated from Streptomyces antibioticus NBRC 13838/Streptomyces scabies JCM 7914 and Streptomyces turgidiscabies JCM 10429, respectively. The planar structures of scabichelin and turgichelin were elucidated by mass spectrometry, and 1- and 2-D NMR spectroscopic analyses of their gallium(III) complexes. The relative and absolute stereochemistry of the metabolites was determined by the modified Marfey's method in conjunction with computational modelling and NOESY NMR analysis of Ga-scabichelin and Ga-turgichelin. Genome sequence analysis of the plant pathogen Streptomyces scabies 87.22 identified a gene cluster containing a gene encoding a nonribosomal peptide synthetase (NRPS) that was predicted to direct the production of a pentapeptide with structural similarities to scabichelin and turgichelin. Comparative LC-MS/MS analyses of iron-deficient culture supernatants from wild type S. scabies 87.22 and a mutant in which the NRPS gene had been disrupted, and scabichelin purified from S. antibioticus, showed that scabichelin is the metabolic product of the cryptic gene cluster, strongly suggesting that it functions as a siderophore.

Antioxidant activity of different parts of Tetrataenium lasiopetalum.

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.

Biological activities of the polysaccharides produced in submerged culture of two edible Pleurotus ostreatus mushrooms.

Exopolysaccharides (EPS) and internal (intracellular) polysaccharides (IPS) obtained from the Pleurotus ostreatus M2191 and PBS281009 cultivated using the batch system revealed an average of between 0.1-2 (EPS) and 0.07-1.5 g/L/day (IPS). The carbohydrate analysis revealed that the polysaccharides comprised 87-89% EPS and 68-74% IPS. The investigation of antioxidant activity in vitro revealed a good antioxidant potential, particularly for the IPS and EPS isolated from PBS281009, as proved by the EC(50) value for DPPH, ABTS scavenging activity, reducing power, and iron chelating activity.

Spectaflavoside A, a new potent iron chelating dimeric flavonol glycoside from the rhizomes of Zingiber spectabile Griff.

The rhizomes of Zingiber spectabile yielded a new dimeric flavonol glycoside for which the name kaempferol-3-O-(4″-O-acetyl)-α-L-rhamnopyranoside-(I-6,II-8)-kaempferol-3-O-(4″-O-acetyl)-α-L-rhamnopyranoside; spectaflavoside A (1) was proposed, along with kaempferol and its four acetylrhamnosides (2-6), demethoxycurcumin (7) and curcumin (8). The structure of spectaflavoside A was elucidated by spectroscopic methods including, 1D and 2D NMR techniques. This is the first report on the occurrence of a dimeric flavonol glycoside in the Zingiberaceae and the second in nature. Spectaflavoside A was found to be a potent iron chelating agent.

An in vitro perspective to cholinesterase inhibitory and antioxidant activity of five Gentiana species and Gentianella caucasea.

The dichloromethane (DCM), ethyl acetate (EtOAc), and methanol extracts from the leaves, roots, and flowers of the five species of Gentiana (Gentiana asclepiadea, Gentiana cruciata, Gentiana olivieri, Gentiana septemfida, and Gentiana verna) and Gentianella caucasea were investigated for their inhibitory activity against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) and antioxidant effect using 2,2-diphenyl-1-picrylhydrazyl radical scavenging, metal-chelation capacity, and ferric-reducing antioxidant power assays. Total phenol and flavonoid contents of the extracts were determined spectrophotometrically. The presence of some characteristic compounds found in Gentiana species (gentiopicroside, swertiamarin, isoorientin, isovitexin and vitexin) was analyzed in the extracts by thin layer chromatography. The flower DCM extract of G. verna exerted the highest inhibition against AChE (53.65 ± 1.03%), whereas the root EtOAc extract of G. cruciata was the most effective in BChE inhibition assay (50.72 ± 0.75%) at 100 µg ml⁻¹. The extracts of G. verna were also found to be more active in the antioxidant tests.

Antioxidant effect of Stryphnodendron rotundifolium Martius extracts from Cariri-Ceará State (Brazil): potential involvement in its therapeutic use.

Stryphnodendron rotundifolium is a phytotherapic used in the northeast of Brazil for the treatment of inflammatory processes which normally are associated with oxidative stress. Consequently, we have tested the antioxidant properties of hydroalcoholic (HAB) and aqueous extracts (AB) from the bark and aqueous extract (AL) from the leaves of Stryphnodendron rotundifolium to determine a possible association between antioxidant activity and the popular use of this plant. Free radical scavenger properties were assessed by the quenching of 1',1'-diphenil-2-picrylhydrazyl (DPPH) and the calculated IC(50) were: HAB = 5.4 ± 0.7, AB = 12.0 ± 2.6, and AL = 46.3 ± 12.3 µg/mL. Total phenolic contents were: HAB = 102.7 ± 2.8, AB = 114.4 ± 14.6, and AL = 93.8 ± 9.1 µg/mg plant). HPLC/DAD analyses indicated that gallic acid, catechin, rutin and caffeic acid were the major components of the crude extracts of S. rotundifolium. Plant extracts inhibited Fe(II)-induced lipid peroxidation in brain homogenates. Iron chelation was also investigated and only HBA exhibited a weak activity. Taken together, the results suggest that S. rotundifolium could be considered an effective agent in the prevention of diseases associated with oxidative stress.