Antibacterial and antioxidant activities of the essential oil and methanol extracts of Bidens frondosa Linn

Antibacterial and antioxidant potential of essential oil, extract and its fractions of Bidens frondosa Linn were evaluated. Sixty‐one components representing 95.41% of the total oil were identified. The essential oil (7.5 μL disc^?1), methanol extract and its different organic subfractions (0.5 μg disc^?1) of B. frondosa displayed a great potential of antibacterial activity against Staphylococcus aureus (ATCC 6538 and KCTC 1916), Listeria monocytogenes ATCC 19116, Bacillus subtilis ATCC 6633, Pseudomonas aeruginosa KCTC 2004, Salmonella enteritidis KCTC 12021 and Enterobacter aerogenes KCTC 2190. Antioxidant activity was evaluated by using 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) assay. The free radical scavenging activity of ethyl acetate (EtOAc) fraction was superior to all other fractions (IC₅₀ = 11.96 μg mL^?1), which was higher than synthetic antioxidant butylated hydroxyanisole, (IC₅₀ = 18.27 μg mL^?1). Furthermore, the amount of total phenolic compounds was determined and its content in EtOAc fraction was the highest as compared to methanol extract or other fractions. The results indicate that the oil and extracts of B. frondosa could serve as an important bio‐resource of antimicrobial agents and antioxidants for using in the food industries.     

Antimicrobial activity of food-compatible plant extracts and chitosan against naturally occurring micro-organisms in tomato juice

BACKGROUND: Chitosan (AC) and five hydroalcoholic extracts from Lithospermum erythrorhizon (SE), Rheum palmatum (RE), Thymus vulgaris (AT), Lippia citriodora (PLX) and a mixture of Rosmarinus officinalis, Salvia lavandulifolia and Thymus mastichina (LA) were tested for antimicrobial activity against bacteria, yeasts and filamentous fungi using two broth dilution methods. The effects of adding single extracts on naturally occurring micro‐organisms and sensory qualities of raw tomato juice were also evaluated. RESULTS: SE extract exhibited the strongest activity, with minimum inhibitory concentrations (MICs) of 100–400 µg mL^?1 for Gram‐positive and 1600–3200 µg mL^?1 for Gram‐negative bacteria. Enterobacter aerogenes showed the greatest susceptibility to AC (MIC 1600 µg mL^?1). Lethal effects of extracts and AC were achieved at a minimum bactericidal concentration (MBC)/MIC ratio of 2 in 88% of assays. SE and RE extracts and AC also exhibited antifungal effect against yeasts, but they had no activity on filamentous fungi. Control and 100 mg L^?1 SE‐added tomato juices did not differ in acceptance, but this SE concentration was not effective in the control of microbial load throughout cold storage. CONCLUSION: Results confirm the antimicrobial potential of the plant extracts, but additional research is needed until the agents responsible for the activities have been determined in order to use them as natural constituents of multiple‐barrier food preservation systems. Copyright © 2012 Society of Chemical Industry     

Chemical composition and in vitro antioxidant studies on Syzygium cumini fruit

Syzygium cumini, widely known as Jamun, is a tropical tree that yields purple ovoid fleshy fruit. Its seed has traditionally been used in India for the treatment of diabetes. Based on the available ethno‐pharmacological knowledge, further studies were extended to understand the chemical composition and antioxidant activities of three anatomically distinct parts of fruit: the pulp, kernel and seed coat. Fruit parts, their corresponding ethanol extracts and residues were evaluated for chemical composition. The alcoholic extract was evaluated for its antioxidant potential against DPPH^?, OH^?, O₂^?? and lipid peroxidation. The whole fruit consisted of 666.0 ± 111.0 g kg^?1 pulp, 290.0 ± 40.0 g kg^?1 kernel and 50.0 ± 15.0 g kg^?1 seed coat. Fresh pulp was rich in carbohydrates, protein and minerals. Total fatty matter was not significant in all three parts of fruit. Detailed mineral analysis showed calcium was abundant in all fruit parts and extracts. Total phenolics, anthocyanins and flavonoid contents of pulp were 3.9 ± 0.5, 1.34 ± 0.2 and 0.07 ± 0.04 g kg^?1, respectively. Kernel and seed coat contained 9.0 ± 0.7 and 8.1 ± 0.8 g kg^?1 total phenolics respectively. Jamun pulp ethanol extract (PEE), kernel ethanol extract (KEE) and seed coat ethanol extract (SCEE) showed a high degree of phenolic enrichment. DPPH radical scavenging activity of the samples and standards in descending order was: gallic acid > quercetin > Trolox > KEE > BHT > SCEE > PEE. Superoxide radical scavenging activity (IC₅₀) of KEE was six times higher (85.0 ± 5.0 µg mL^?1) compared to Trolox (540.0 ± 5.0 µg mL^?1) and three times compared to catechin (296.0 ± 11.0 µg mL^?1). Hydroxyl radical scavenging activity (IC₅₀) of KEE was 151.0 ± 5.0 µg mL^?1 which was comparable with catechin (188.0 ± 6.0 µg mL^?1). Inhibition of lipid peroxidation of the extracts was also studied and their activity against peroxide radicals were lower than that of standard compounds (BHT, 79.0 ± 4.0 µg mL^?1; quercetin, 166.0 ± 13.0 µg mL^?1; Trolox, 175.0 ± 4.0 µg mL^?1; PEE, 342.0 ± 17.0 µg mL^?1; KEE, 202.0 ± 13.0 µg mL^?1 and SCEE, 268.0 ± 13.0 µg mL^?1. Copyright © 2007 Society of Chemical Industry     

Antigenotoxicity of extracts from Pleurotus citrinopileatus

While Pleurotus citrinopileatus is a widely used edible mushroom, little is known about its physiological effects. Extracts, including aqueous extract, water‐soluble polysaccharide (WSP), crude protein solution (CPS) and residue from chloroform–ethyl acetate–methanol elution (CEM), were obtained first from fruiting bodies, through a solid‐state culture, and then from the mycelium, through a submerged culture. This study explored the antigenotoxicity effects of these extracts from Pleurotus citrinopileatus via the Ames test and a spore rec‐Assay. The results showed that, regardless of where the extract came from, the fruiting body or the mycelium, the antigenotoxicity effect was highest for CEM, followed by CPS, aqueous extract and WSP. The results of the Ames test indicated that, among several mutagens, CEM had the highest inhibition rate against AFB_l in TA98 and TA100 and the lowest inhibition rate against NQNO. The concentrations of the various extracts were as follows: water extracts were 1 mg ml^?1 and 5 mg ml^?1 WSP, while CPS and CEM were 0.4 mg ml^?1 and 2 mg ml^?1, respectively; the higher the concentration of the extract, the higher the antimutagenicity effect. The results of the rec‐Assay indicated that CEM had the highest anti‐DNA‐damaging activity with or without the S9 mixture; the higher the concentration, the more significant the effect (p < 0.05). The anti‐DNA‐damaging activities were lower in the water extract concentrations, at 30 µg disc^?1 dry weight^?1, while the WSP, CPS and CEM at 12, 150 and 60 µg disc^?1, respectively, were high. Copyright © 2004 Society of Chemical Industry     

Suppression of postharvest blue mould of apple fruit by Cryptococcus laurentii and N6‐benzyladenine

BACKGROUND: Cryptococcus laurentii is a well‐known postharvest yeast antagonist. N⁶‐benzyladenine (6‐BA), a cytokinin plant hormone, has a role in retarding ripening and senescence of harvested produce. This study was conducted to evaluate the efficacy of C. laurentii and 6‐BA in reducing the blue mould disease of apple fruit. RESULTS: The combination of C. laurentii with 6‐BA (20 µg mL^?1) was more effective in suppressing the Penicillium expansum infection in apple fruit wounds than C. laurentii alone, although 6‐BA (20 µg mL^?1) alone neither affected the growth of C. laurentii nor reduced the incidence of the blue mould disease in vivo. Moreover, treatment of apple fruit with C. laurentii and 6‐BA (20 µg mL^?1) resulted in stimulation of superoxide dismutase activity but in inhibition of the increase in peroxidase activity. CONCLUSION: 6‐BA (20 µg mL^?1) could enhance the efficacy of C. laurentii in reducing the postharvest blue mould disease of apple fruit, which offered great potential in minimizing the postharvest decay of apple fruit in an integrated pest management strategy. Copyright © 2008 Society of Chemical Industry     

The in vitro antioxidant and antimicrobial activities of the essential oil and various extracts of Origanum syriacum L var bevanii

The present work examines the in vitro antioxidant and antimicrobial properties of the essential oil and various extracts from the herbal parts of Origanum syriacum L var bevanii. Polar subfractions of methanol extracts from both deodorised and non‐deodorised materials showed the highest DPPH (2,2‐diphenyl‐l‐picrylhydrazyl) radical‐scavenging activity, with IC₅₀ values of 21.40 and 26.98 µg ml^?1 respectively, whereas the IC₅₀ of the essential oil was 134.00 µg ml^?1. The antioxidant potential of the extracts appeared to be closely related to the presence of polar phenolics. However, the inhibitive effect on linoleic acid oxidation might be promoted by the presence of non‐polar phenolics, as both hexane and dichloromethane extracts showed high antioxidant activities. The antimicrobial activity of the essential oil was superior to those of the other extracts. Nineteen compounds representing 962 g kg^?1 of the essential oil were identified; carvacrol (669 g kg^?1) was the main component. Overall, the results suggest that the essential oil and extracts from the herbal parts of O syriacum could be used as natural preservative ingredients in the food industry. Copyright © 2004 Society of Chemical Industry     

Antioxidant properties of Korean black raspberry wines and their apoptotic effects on cancer cells

BACKGROUND: The objective of the study was to determine the antioxidant activities of Korean black raspberry concentrate (KBR: Rubus coreanus Miq.) and Korean black raspberry wine concentrates (KBRW‐1 and KBRW‐2) using the DPPH (2,2‐diphenyl‐1‐picrylhydrazyl) radical scavenging assay. The apoptotic effects of the KBRW concentrates on various cancer cells were also investigated. RESULTS: Both the KBR concentrate and KBRW concentrates showed dose‐related antioxidant activities in the DPPH assay. At concentrations of 500 µg mL^?1 and 1000 µg mL^?1, the KBR concentrate antioxidant activities were 59% and 79%, respectively. KBRW‐1 and KBRW‐2 inhibited radical formation at 500 µg mL^?1 by 19% and 48%, respectively. The antioxidant activity of KBRW‐2 was comparable to various red wines (RW‐1, RW‐2, RW‐3, and RW‐4). However, at 1000 µg mL^?1, the antioxidant activities of KBRW‐1 and KBRW‐2 were 53% and 83% that of α‐tocopherol, respectively. Both RW‐1 and KBRW‐2 showed marked antiproliferative effects on all cancer cell types, with decreases in cell viability greater than 50%. This was co‐related with apoptotic characteristics, including chromatin condensation and apoptotic body formation, as determined by cell morphological assessment. Cell cycle analysis showed that treating AGS cells with RW‐1 and KBRW‐2 resulted in 25% and 30% apoptotic cell accumulation, respectively. KBRW‐2 induced the cleavage of poly(ADP‐ribose) polymerase (PARP) and the activation of caspase‐3 within the AGS cells. Levels of PARP cleavage were increased five‐ and three‐fold by RW‐1 and KBRW‐2, respectively, and the level of caspase‐3 was significantly increased by the treatment with KBRW‐2. CONCLUSION: Overall, the results of this study suggest that Korean black raspberry wine displays antioxidant activity comparable to that of imported red wines, and has anticancer effects that may be attributed to induction of the apoptotic pathway. Copyright © 2009 Society of Chemical Industry     

Characteristics of the leaf parts of some traditional Korean salad plants used for food

BACKGROUND: Total phenolics content, antioxidant activity and cytotoxicity of the methanol extracts from leaf parts of 13 Korean traditional salad plants were investigated in order to determine their properties. RESULTS: The highest phenolics content (mg ferulic acid equivalents kg^?1 dry weight (d.w.), omit one) was found in methanol extracts from Polygonum aviculare, at 293.7 ± 6.0, followed by Euonymus alatus, at 250.7 ± 3.3, Saxifraga stolonifera, at 125.0 ± 8.1 and Ligularia fischeri, at 122.5 ± 5.9. The methanol plant extracts dose‐dependently increased free radical scavenging activity. Methanol extracts of Polygonum aviculare, Euonymus alatus and Saxifraga stolonifera, at 31 mg kg^?1, exhibited the highest 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical scavenging activity (%) by 90.8 ± 4.2, 85.7 ± 3.9 and 64.1 ± 3.2, respectively. According to 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) assay, the methanol extracts from Portulaca oleracea (IC₅₀ < 25.0 µg mL^?1) showed the highest cytotoxicity against Calu‐6, followed by Plantago asiatica (49.2 µg mL^?1) and Osmunda japonica (89.6 µg mL^?1). CONCLUSION: Total phenolics content of the tested plant extracts was correlated with the DPPH radical scavenging activity, suggesting the phenolics compounds are contributing to the antioxidant properties of Korean salad plants. The leaf parts of the 13 Korean traditional salad plants described here that are currently used as foods may also provide some benefit to human health, and research into their potential benefits as preventative and/or therapeutic agents is warranted. Copyright © 2008 Society of Chemical Industry     

Antioxidant and semicarbazide‐sensitive amine oxidase inhibitory activities of alginic acid hydroxamates

The commercial polysaccharides of alginic acid (medium (3500 cps, 2% solution) and low (250 cps, 2% solution) viscosities) were esterified with acidic methanol (1 mmol L^?1 HCl) at 4 °C with gentle stirring for 5 days to obtain methyl esters of medium‐viscosity alginic acid (ME‐MVA) and low‐viscosity alginic acid (ME‐LVA). These ME‐MVA and ME‐LVA were reacted with alkaline hydroxylamine to obtain medium‐viscosity alginic acid hydroxamates (MVA‐NHOH) and LVA‐NHOH. The percentages of hydroxamic acid content in MVA‐NHOH and LVA‐NHOH were calculated as 25% and 20%, respectively. The hydroxamate derivatives of alginic acid were used to test the antioxidant and semicarbazide‐sensitive amine oxidase (SSAO) inhibitory activities in comparison with original materials (MVA and LVA). The half‐inhibition concentrations, IC₅₀, of scavenging activity against 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) were 24.5 and 29.8 µg mL^?1 for MVA‐NHOH and LVA‐NHOH, respectively. However, few scavenging activities of the MVA and LVA were found at the same concentrations. The IC₅₀ of the positive control of butylated hydroxytoluene was 5 µg mL^?1. The scavenging activity of DPPH radical was pH‐dependent, and the optimal pH for both of MVA‐NHOH and LVA‐NHOH was the Tris‐HCl buffer (pH 7.9). Using electron spin resonance (ESR) to detect the activity of scavenging hydroxyl radicals, both alginic acid hydroxamates showed dose‐dependent scavenging activities, and the IC₅₀ was 90 and 92 µg mL^?1, respectively, for MVA‐NHOH and LVA‐NHOH. Both alginic acid hydroxamates also exhibited protection against hydroxyl radical‐mediated DNA damage. Both MVA‐NHOH and LVA‐NHOH showed dose‐dependent inhibitory activities against bovine SSAO (2.53 units); the IC₅₀ was 0.16 and 0.09 µg mL^?1, respectively, for MVA‐NHOH and LVA‐NHOH, compared with 3.81 µg mL^?1 of semicarbazide (positive controls). Amine oxidase activity staining also revealed that both MVA‐NHOH and LVA‐NHOH exhibited SSAO inhibitory activities. Both MVA‐NHOH and LVA‐NHOH showed mixed non‐competitive inhibition against bovine SSAO. It was found that the V′_max value was reduced and the K′_m value was either increased (added MVA‐NHOH, 0.05 µg mL^?1) or reduced (added LVA‐NHOH, 0.11 µg mL^?1) in the presence of alginic acid hydroxamate. Copyright © 2006 Society of Chemical Industry     

Volatile compounds and antimicrobial and antioxidant activities of the essential oils of the needles of Pinus densiflora and Pinus thunbergii

BACKGROUND: To investigate the volatile compounds and the antibacterial and antioxidant effects of the essential oils of Pinus densiflora needles (EPDN) and Pinus thunbergii needles (EPTN), the volatile compounds of steam‐distilled essential oils were analysed by gas chromatography–mass spectrometry. Antibacterial activities were analysed by performing disc‐agar diffusion assay and determining the minimum inhibitory concentrations (MICs) of the essential oils. Antioxidant activities were analysed via radical‐ and nitrite‐scavenging activity assays. RESULTS: The yields of EPDN and EPTN were 0.304% (v/w) and 0.296% (v/w), respectively. In the antibacterial activity assay, the MICs of EPDN and EPTN for Klebsiella pneumoniae, Shigella flexneri and Proteus vulgaris were < 0.4 mg mL^?1. In the antioxidant activity assay, the 50% inhibitory concentrations (IC₅₀) of EPDN and EPTN were 120 and 30 µg mL^?1, respectively. At 1680 µg mL^?1, both EPDN and EPTN exhibited > 50% nitrite‐scavenging activity. CONCLUSION: EPDN can be used as a natural antimicrobial substance. Copyright © 2011 Society of Chemical Industry     

Chemical composition,antioxidant and cytotoxicity activities of the essential oils of Myristica fragrans and Morinda citrifolia

BACKGROUND: In this study the chemical composition, antioxidant activities and cytotoxic effect of the essential oils of Myristica fragrans (nutmeg) and Morinda citrifolia (mengkudu) were determined. RESULTS: Thirty‐eight compounds in nutmeg oil and six compounds in mengkudu oil were identified by gas chromatography–mass spectrometry. The free radical scavenging activity of nutmeg oil was superior of that mengkudu oil. The MTT assay of nutmeg oil on human colorectal carcinoma (HCT‐116) and human breast carcinoma (MCF‐7) cell lines showed IC₅₀ values of 78.61 and 66.45 µg mL^?1, respectively. The mengkudu oil exhibited IC₅₀ values of 91.46 and 78.15 µg mL^?1 for HCT‐116 and MCF‐7, respectively. CONCLUSION: The results showed that nutmeg oil can be developed as potent anti‐cancer and antioxidant drugs. Copyright © 2011 Society of Chemical Industry     

Chemical composition,antibacterial and antifungal activities of seed essential oil of Ferulago angulata

The aim of this study was to determine the chemical composition and the in vitro antimicrobial effects of seed essential oil of Ferulago angulata. The oil analyses by GC and GC/MS resulted in the identification of 39 compounds representing 91.07% of the oil. The major constituents were (Z)-β-ocimene (19.93%), α-pinene (15.50%), p-cymene (7.67%), sabinene (7.49%), β-phellandrene (5.5%), and α-phellandrene (4.95%). The oil was also screened for its antimicrobial properties against six bacteria (Erwinia amylovora, Xanthomonas oryzae, Pseudomonas syringae, Pectobacterium carotovorum, Ralstonia solanacearum, Bacillus thuringiensis) and six fungi (Alternaria alternata, Culvularia fallax, Macrophomina phaseolina, Fusarium oxysporum, Cytospora sacchari, Colletotrichum tricbellum). According to the results of antibacterial activity, B. thuringiensis (with 8 µL mL^?1 minimal inhibitory concentration (MIC) and 15 µL mL^?1 minimum bactericidal concentration (MBC)) was the most sensitive bacterium; P. carotovorum and R. solanacearum (with 20 µL mL^?1 MIC and 30< MBC) were the most resistant bacteria. Additionally, a broad differentiation against all of the tested fungi showed that the most susceptible and resistant fungi after 6 days at the highest concentration (800 µL L^?1) were F. oxysporum (100.0 ± 0.00%) and C. tricbellum (52.50 ± 1.67%) of growth inhibition, respectively.     

Antioxidant activity of hydrolysates derived from porcine plasma

BACKGROUND: In China alone, more than 400 million pigs are slaughtered each year to provide meat. Porcine blood is rich in proteins but is usually discarded, which can cause environmental contamination. Recovering porcine blood and converting it to high‐value products is therefore economically and environmentally desirable. However, very little information on antioxidant peptides from porcine blood by‐products is currently available. In this study the antioxidant properties of porcine plasma hydrolysates PPE and PPA prepared with pepsin and papain respectively were investigated. RESULTS: Both PPE and PPA showed excellent antioxidant activity in a linoleic acid system (AL) compared with α‐tocopherol (VE) at the same concentration (P < 0.01). Their activities were respectively 3.33 and 1.83 times stronger than that of VE at a concentration of 10 µg mL^?1 and 5.4 and 5.6 times stronger at 100 µg mL^?1. The 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical‐scavenging activity (DRSA) reached 48.4 and 43.1% for PPE and PPA respectively at 500 µg mL^?1. The ferrous ion‐chelating power (FICP) of PPE at 100 µg mL^?1 was about 1.5 times stronger than that of 10 µmol L^?1 ethylene diamine tetraacetic acid (EDTA) in a 50 µmol L^?1 Fe²⁺ system, whereas the FICP of PPA at 100 µg mL^?1 was 61% that of 10 µmol L^?1 EDTA. Furthermore, PPE was separated on Resource 15RPC and Superdex peptide 10/300GL columns, and the antioxidant activity of the peptides and its relationship to their polarity and molecular weight (MW) were analysed. The hydrolysate was divided into four groups (R1–R4) with hydrophobicities ranging from weak to strong by Resource 15RPC, while it was divided into three groups (S1, MW 7–12 kDa; S2, MW 3–7 kDa; S3, MW 1–3 kDa) by Superdex peptide 10/300GL. CONCLUSION: The results showed that AL was significantly and positively correlated with the relative amounts of R1, S2 and S3 and that DRSA was dependent on R3 and S1. The fractions of PPE were not responsible for FICP. Copyright © 2009 Society of Chemical Industry     

Alginate–calcium coating incorporating nisin and EDTA maintains the quality of fresh northern snakehead (Channa argus) fillets stored at 4 °C

BACKGROUND: Antimicrobial packaging is a novel food packaging technology for controlling the growth of food‐borne pathogens or spoilage bacteria in ready‐to‐eat food products. Fresh fish are highly perishable foodstuffs and are extremely susceptible to microbial activities. An alginate–calcium coating incorporating nisin and ethylenediaminetetraacetic acid (EDTA) was used as an antimicrobial packaging to maintain the quality of northern snakehead (Channa argus) at refrigeration temperature (4 ± 1 °C). Northern snakehead fillets were left untreated (CK), or were treated with 1000 IU mL^?1 nisin and 150 µg mL^?1 EDTA (T1), alginate–calcium coating (T2), or alginate–calcium coating incorporating 1000 IU mL^?1 nisin and 150 µg mL^?1 EDTA (T3). RESULTS: All treatments retarded the decay of the fish fillets. T1 more efficiently inhibited the growth of total viable mesophilic bacteria (P < 0.05) and total psychrophilic bacteria (P > 0.05) than did T2 or T3. Coating treatments predominantly reduced chemical spoilage, reflected in total volatile base nitrogen (P > 0.05), trimethylamine (P > 0.05), pH (P < 0.05), and thiobarbituric acid (P < 0.05), retarded water loss (P < 0.05), and increased the overall sensory scores of fish fillets (P < 0.05) compared with those of T1. There was no significant difference between the coating treatments T2 and T3 (P > 0.05). CONCLUSION: Alginate–calcium coating treatments efficiently enhanced the quality of northern snakehead fillets during storage. Copyright © 2009 Society of Chemical Industry     

Chemical composition and antioxidant and antimicrobial activities of essential oil of Allium sphaerocephalon L. subsp. sphaerocephalon (Liliaceae) inflorescences

BACKGROUND: Allium sphaerocephalon is a wild‐growing plant commonly used as an onion substitute. In this study the essential oil obtained from A. sphaerocephalon subsp. sphaerocephalon inflorescences was analysed by gas chromatography and gas chromatography/mass spectrometry and also evaluated for in vitro antioxidant and antimicrobial activities. The obtained results are reported for the first time and discussed with respect to the sulfur compounds detected in the essential oil. RESULTS: Ninty‐one compounds were identified, representing 91.6% (w/w) of the total oil. Major constituents of the analysed sample were shyobunol (15.3%), β‐caryophyllene (8.1%), α‐cadinol (7.8%), 3,5‐diethyl‐1,2,4‐trithiolane (isomer II, 5.9%) and δ‐cadinene (5.2%). The diluted oil had an antioxidant capacity of 160 000 ± 111 µmol α‐tocopherol acetate equivalents g^?1. Its antimicrobial activity was evaluated against five bacterial and two fungal strains using the broth microdilution assay. Among the micro‐organisms tested, the most susceptible strains were Pseudomonas aeruginosa (minimal inhibitory/bactericidal concentration = 0.08/2.5 mg mL^?1) and Aspergillus niger (minimal inhibitory/fungicidal concentration = 0.31/0.63 mg mL^?1). CONCLUSION: The results showed that the examined species had strong antioxidant and antimicrobial properties and are in accordance with the popular use of plants belonging to the genus Allium in traditional medicine, emphasising the necessity of further detailed study of the active principles in Allium species. Copyright © 2010 Society of Chemical Industry     

Antioxidant activities of different Teucrium montanum L. Extracts

The sequential extraction of Teucrium montanum L. was realised with five solvents of different polarities (70% methanol, petroleum ether, chloroform, ethyl acetate, and n‐butanol) and HPLC method was used for identification of phenolic compounds. The total phenolic content of the extracts was determined spectrophotometrically according to the Folin–Ciocalteau procedure and range from 0 to 296 mg g^?1. The antioxidant activity of extracts was tested by measuring their ability to scavenge reactive hydroxyl radical during the Fenton reaction, using electron spin resonance (ESR) spectroscopy. Moreover, the influence of these extracts on lipid peroxyl radicals obtained during lipid peroxidation of: (1) sunflower oil (37 °C, 3 h) induced by 4,4′‐azobis(4‐cyanovaleric acid) (ACVA) and (2) liposomes induced by 2,2′‐azobis(2‐amidino‐propane)dihydrochloride (AAPH) was studied. n‐Butanol extract, because of the highest content of total phenolic compounds (296 mg g^?1) had the best antioxidant activity (100% at 0.16 mg mL^?1 in Fenton reaction system; 90.57% at 5 mg mL^?1 in system I; 100% at 5 mg mL^?1 in system II).     

Antioxidant/anti-inflammatory activities and total phenolic content of extracts obtained from plants grown in Vietnam

BACKGROUND: Medicinal plants have been used to treat various diseases since ancient times. Their specific activities, such as antioxidant, anti‐inflammatory and anti‐cancer, have been studied intensively. In particular, plants grown in Vietnam have attracted considerable attention among food chemists as ideal sources of natural medicinal chemicals. RESULTS: The methanol extracts from three edible Vietnamese‐grown plants, Tram, Voi and Gac, tested with the DPPH assay showed antioxidant activities of 91.7 ± 0.4, 63.4 ± 0.7 and 3.7 ± 0.1% respectively. The malonaldehyde/gas chromatography assay also revealed strong antioxidant activity in Tram and Voi at a level of 25 µg mL^?1 (95.5 ± 0.3 and 78.5 ± 1.4% respectively). These results were confirmed by the thiobarbituric acid assay. The antioxidant activities correlated positively with the level of total phenolics in all plants. Tram exhibited dose response‐related lipoxygenase‐inhibitory activity, with values of 74.2 ± 3.1% at 5 µg mL^?1, 62.0 ± 0% at 0.5 µg mL^?1 and 3.0 ± 1.5% at 0.05 µg mL^?1. Conversely, Voi and Gac showed negative anti‐lipoxygenase activity. CONCLUSION: The antioxidant/anti‐inflammatory activities and total phenolic contents of the three edible plants grown in Vietnam revealed that they are good sources of supplements for human health. Copyright © 2011 Society of Chemical Industry     

Ochratoxin A in wines,musts and grape juices from Spain

A survey on the occurrence of ochratoxin A (OTA) in 240 grape‐based beverages was carried out. Red and white wines from four different Spanish Designations of Origin (n = 160), musts (n = 20), grape juices (n = 10), ordinary wines (n = 20), special wines (Malaga, muscatel, sherry, vermouth, etc) (n = 20) and sparkling wines (n = 10) were assayed for OTA content using immunoaffinity column clean‐up and high‐performance liquid chromatography with fluorimetric detection (detection limit 0.05 µg l^?1). Forty‐three (17.9%) of the samples tested contained detectable levels of OTA. The overall mean OTA concentration in red and white wines of Designations of Origin was 0.30 and 0.18 µg l^?1 respectively (ranges 0.05–3.19 and 0.05–1.13 µg l^?1 respectively). The percentage of wine samples with detectable amounts of OTA was higher for red (18.3%) than for white (10%) wines. OTA was also found in two of 10 red ordinary wines (0.68 and 4.24 µg l^?1), whereas none of 10 white ordinary wines contained OTA. The mean OTA amount detected in sparkling wines was 0.44 µg l^?1 (range 0.14–0.71 µg l^?1). Two of 20 must samples contained OTA at low levels (0.08 and 0.18 µg l^?1), while none of 10 grape juice samples contained OTA. Highest amounts of OTA were found in special wines (45%), with a maximum of 15.25 µg l^?1 in a muscatel sample. Copyright © 2004 Society of Chemical Industry     

Anti-complementary activity of enzyme-treated traditional Korean rice wine (Makgeolli) hydrolysates

BACKGROUND: Makgeolli brewed from rice contains about 150 g kg^?1 alcohol and has a fragrance as well as an acidic and sweet taste. During the brewing process, by‐products such as rice bran and brewery cake are produced. At the end of fermentation the matured mash is transferred to a filter cloth and the Makgeolli is squeezed out from the cake, leaving the lees of the mash. These by‐products have continued to increase every year, resulting in an ecological problem. It is therefore important to develop new uses for them. The objective of this study was to use the by‐products from the brewing of Makgeolli as a valuable functional food or nutraceutical. RESULTS: The anti‐complementary activities of crude polysaccharides isolated from Cytolase hydrolysates of Makgeolli lees at concentrations of 1000 and 500 µg mL^?1 were 84.15 and 78.70% respectively. The activity of polysaccharide krestin (PSK) was 60.00% at 1000 µg mL^?1. The active polysaccharide obtained with Cytolase comprised mainly glucose and mannose (molar ratio 1.00:0.62). CONCLUSION: Glucose‐ and mannose‐rich crude polysaccharides were isolated from the Cytolase hydrolysate of Makgeolli lees. The polysaccharides retain anti‐complementary activity to enhance the immune system as a functional food or nutraceutical. Copyright © 2011 Society of Chemical Industry     

Antioxidant and Antihemolytic Activities of Ethanolic Extract of Flowers,Leaves, and Stems of Hyssopus officinalis L. Var. angustifolius

In this study, antioxidant and antihemolytic activities of ethanolic extract of flowers, leaves, and stems of Hyssopus officinalis L. Var. angustifolius were investigated employing different in vitro assay systems. Extracts showed good antioxidant activity. IC₅₀ for 1,1-diphenyl-2-picryl hydrazyl radical-scavenging activity were 148.8 ± 4.31 μg mL^?1 for flowers, 79.9 ± 2.63 μg mL^?1 for stems, and 208.2 ± 6.45 μg mL^?1 for leaves. All extracts showed moderate iron (II) chelating ability. Extracts exhibited good antioxidant activity in the hemoglobin-induced linoleic acid model and also they were capable of scavenging hydrogen peroxide in a concentration dependent manner. Extracts showed good antihemolytic activity againts hydrogen peroxide-induced hemolysis (IC₅₀ were 48.51 ± 2.27 μg mL^?1 for flowers, 19.47 ± 0.73 μg mL^?1 for leaves, and 63.1 ± 2.65 μg mL^?1 for stems). The total amount of phenolic compounds in the extracts was determined as gallic acid equivalents and total flavonoid content was calculated as quercetin equivalents from a calibration curve.