Antioxidant activities of hot water extracts from various spices

Recently, the natural spices and herbs such as rosemary, oregano, and caraway have been used for the processing of meat products. This study investigates the antioxidant activity of 13 spices commonly used in meat processing plants. The hot water extracts were then used for evaluation of total phenolic content, total flavonoids content and antioxidant activities. Our results show that the hot water extract of oregano gave the highest extraction yield (41.33%) whereas mace (7.64%) gave the lowest. The DPPH radical scavenging ability of the spice extracts can be ranked against ascorbic acid in the order ascorbic acid > clove > thyme > rosemary > savory > oregano. The values for superoxide anion radical scavenging activities were in the order of marjoram > rosemary > oregano > cumin > savory > basil > thyme > fennel > coriander > ascorbic acid. When compared to ascorbic acid (48.72%), the hydroxyl radical scavenging activities of turmeric and mace were found to be higher (p < 0.001). Clove had the highest total phenolic content (108.28 μg catechin equivalent (CE)/g). The total flavonoid content of the spices varied from 324.08 μg quercetin equivalent (QE)/g for thyme to 3.38 μg QE/g for coriander. Our results indicate that hot water extract of several spices had a high antioxidant activity which is partly due to the phenolic and flavonoid compounds. This provides basic data, having implications for further development of processed food products.     

Evaluation of Antioxidant and Antiproliferative Properties of Three Actinidia (Actinidia kolomikta, Actinidia arguta, Actinidia chinensis) Extracts in Vitro

The total phenolic content, total flavonoid content, vitamin C content, and antioxidant activities of ethanol extracts from different kiwifruit varieties (Actinidia kolomikta, Actinidia arguta, Actinidia chinensis) were determined in this study. Multiple scavenging activity assays including the hydroxyl radical, O(2) (-)·radical, DPPH, and the ABTS(+) radical scavenging activity assays were used to identify the antioxidant activities of Actinidia extracts. The cell viability of HepG2 and HT-29 cells was also examined in this study. The results demonstrated that the Actinidia kolomikta extract had a higher antioxidant activity than the other two Actinidia extracts. There is a positive correlation between antioxidant activity and the polyphenols and vitamin C content in all three extracts (R(2) ≥ 0.712, p < 0.05). The Actinidia arguta extract had the highest inhibitory effect on HepG2 and HT-29 cell growth. These results provide new insight into the health functions of fruit and demonstrate that Actinidia extracts can potentially have health benefits.     

不同萃取技术获得的Artemisia sp的甲醇提取物其抗氧化和抗菌活性的比较

The polyphenol content,antioxidant and antimicrobial activities of the extracts obtained by classical, ultrasonic and Soxhlet extractions from dry aerial parts of two Artemisia species(Artemisia vulgaris and Artemisia campestris)were compared.Ultrasound positively affected the yield of extractive substance and the kinetics of extraction,but the extract obtained by the classical extraction showed the highest antioxidant activities and contained higher total contents of phenolic compounds and flavonoids than the extracts obtained by two other extraction techniques.Both flavonoid aglycones(apigenin,quercetin,quercetin 3,3′-dimethyl ether)and flavonoid glycosides(rutin,hyperoside and kaempferol 3-rhamnoside)were identified by thin layer chromatograph(TLC)analysis in the extracts from both species.A.campestris extracts were richer in quercetin than A.vulgaris and its antimicrobial activity was also better than A.vulgaris.Extracts obtained from both species were found to be more effective on the tested yeasts than bacteria.The kinetics of the total extractive substances,such as phenolic,flavonoids and quercetin extraction,was successfully described by the model of unsteady-state diffusion.     

果蔬抗氧化活性与总酚含量相关性研究

利用β-胡萝卜素-亚油酸乳化液氧化法对杭州市场上常见的41种果蔬进行了抗氧化活性的研究,并测定其总酚的含量。结果表明:大多数果蔬都具有一定的抗氧化活性,其中香椿、芦蒿、莴笋叶、水芹、茼蒿菜、马齿苋、藕的抗氧化活性较强,其总酚含量也较高,说明果蔬抗氧化活性的强弱与果蔬所含的酚类物质有一定的关联性。     

Phenolic Compounds from Halimodendron halodendron (Pall.) Voss and Their Antimicrobial and Antioxidant Activities

Halimodendron halodendron has been used as forage in northwestern China for a long time. Its young leaves and flowers are edible and favored by indigenous people. In this study, eleven phenolic compounds were bioassay-guided and isolated from the aerial parts of H. halodendron for the first time. They were identified by means of physicochemical and spectrometric analysis as quercetin (1), 3,5,7,8,4′-pentahydroxy-3′-methoxy flavone (2), 3-O-methylquercetin (3), 3,3′-di-O-methylquercetin (4), 3,3′-di-O-methylquercetin-7-O-β-d-glucopyranoside (5), isorhamentin-3-O-β-d-rutinoside (6), 8-O-methylretusin (7), 8-O-methylretusin-7-O-β-d-glucopyranoside (8), salicylic acid (9), p-hydroxybenzoic acid (ferulic acid) (10), and 4-hydroxy-3-methoxy cinnamic acid (11). They were sorted as flavonols (1–6), soflavones (7 and 8), and phenolic acids (9–11). Among the compounds, flanools 1–4 revealed a strong antibacterial activity with minimum inhibitory concentration (MIC) values of 50–150 μg/mL, and median inhibitory concentration (IC₅₀) values of 26.8–125.1 μg/mL. The two isoflavones (7 and 8) showed moderate inhibitory activity on the test bacteria. Three phenolic acids (9, 10 and 11) showed strong antibacterial activity with IC₅₀ values of 28.1–149.7 μg/mL. Antifungal activities of the compounds were similar to their antibacterial activities. All these phenolic compounds showed significant antimicrobial activity with a broad spectrum as well as antioxidant activity based on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and β-carotene-linoleic acid bleaching assays. In general, the flavonol aglycones with relatively low polarity exhibited stronger activities than the glycosides. The results suggest the potential of this plant as a source of functional food ingredients and provide support data for its utilization as forage as well.     

Antioxidant Property Enhancement of Sweet Potato Flour under Simulated Gastrointestinal pH

Sweet potato is known to be rich in healthful antioxidants, but the stability of its antioxidant properties under gastrointestinal pH is very much unknown. Hence, this study aimed to evaluate the changes in antioxidant properties (total contents of phenolics and flavonoids as well as antioxidant activity) of sweet potato flour (SPF) under simulated gastrointestinal pH conditions. It was found that the yield of SPF crude phenolic extract increased from 0.29 to 3.22 g/100 g SPF upon subjection to gastrointestinal pH conditions (p < 0.05). Also elevated significantly were the total phenolic content (TPC), total flavonoid content (TFC) and antioxidant activity of SPF (p < 0.05). In summary, the antioxidant properties of SPF were enhanced under gastrointestinal pH conditions, suggesting that SPF might possess a considerable amount of bound phenolic and other antioxidative compounds. The antioxidant properties of SPF are largely influenced by pH and thus might be enhanced during the in vivo digestive process.     

Total Phenolic Contents and Antioxidant Capacities of Selected Chinese Medicinal Plants

Antioxidant capacities of 56 selected Chinese medicinal plants were evaluated using the Trolox equivalent antioxidant capacity (TEAC) and ferric reducing antioxidant power (FRAP) assays, and their total phenolic content was measured by the Folin-Ciocalteu method. The strong correlation between TEAC value and FRAP value suggested that the antioxidants in these plants possess free radical scavenging activity and oxidant reducing power, and the high positive correlation between antioxidant capacities and total phenolic content implied that phenolic compounds are a major contributor to the antioxidant activity of these plants. The results showed that Dioscorea bulbifera, Eriobotrya japonica, Tussilago farfara and Ephedra sinica could be potential rich sources of natural antioxidants.     

用传统和超声提取的松果菊(紫锥菊属)的抗氧化和抗菌活性

Antioxidant and antimicrobial activities of Echinacea purpurea L. (Asteraceae) extracts obtained by classical and ultrasound solvent extraction were compared. The dry aerial part of plant was extracted by 70% ctha-nol at a solid-to-liquid ratio of 1 : 10 (m/v) and 25℃. The extract obtained by classical solvent extraction contained 29% larger amounts of phenolic compounds and 20% higher content of flavonoids. 2,2-diphenyl-l-picril hydrazyl radical (DPPH) scavenging reached 93.6% and the values of EC50 were (34.16±0.65) μg·ml-1and (65.48±1.12) μg·ml-1 for the extracts obtained by the classical and ultrasound extractions, respectively. The extracts, independent of the extraction technique applied, showed a considerable growth inhibition on Candida albicans and Saccharo-myces cerevisiae, while no growth inhibition zones were observed for Aspergillus niger. The diameters of inhibition zone observed for all the microorganisms were larger for extracts obtained by classical extraction than those by ultrasoud extraction.     

Antioxidant activity of brazilian vegetables and its relation with phenolic composition

Vegetables are widely consumed in Brazil and exported to several countries. This study was performed to evaluate the phenolic content and antioxidant activity of vegetables commonly consumed in Brazil using five different methods, namely DPPH and ABTS free radical, β-carotene bleaching, reduction of Fe³⁺ (FRAP), oxidative stability in Rancimat, and the chemical composition using gas chromatography-mass spectrometry (GC-MS). The content of phenolic compounds ranged from 1.2 mg GA/g (carrot) to 16.9 mg GA/g (lettuce). Vegetables presenting the highest antioxidant activity were lettuce (77.2 μmol Trolox/g DPPH^•; 447.1 μmol F²⁺/g FRAP), turmeric (118.6 μmol Trolox/g ABTS^•+; 92.8% β-carotene), watercress and broccoli (protective factor 1.29—Rancimat method). Artichoke, spinach, broccoli, and asparagus also showed considerable antioxidant activity. The most frequent phenolic compounds identified by GC-MS were ferulic, caffeic, p-coumaric, 2-dihydroxybenzoic, 2,5-dihydroxybenzoic acids, and quercetin. We observed antioxidant activity in several vegetables and our results point out their importance in the diet.     

Influence of hot air fluidized bed drying on quality changes of purple rice

The influence of drying using a fluidization technique on the quality of purple rice was investigated in this study. The results demonstrated that the initial moisture of rice was 28.3% dry basis (db). Compared to the sun-dried or reference purple rice samples, the influence of drying at temperatures ranging from 100 to 150°C did not affect the quality of color, anthocyanin content, total phenolic content, or antioxidant activity. At this initial moisture level, samples should be dried at 150°C air because such temperatures yield the highest drying rate. Drying at this temperature also causes an increase in the head purple rice yield because of the gelatinization of starch. In the case of an initial moisture content of 33.3% (db), the drying temperature should not exceed 130°C.     

Synthesis and antioxidant activities in polyolefin of dendritic antioxidants with hindered phenolic groups and tertiary amine

Two novel primary antioxidants with dendritic structure and hindered phenolic groups were synthesized using 3‐(3,5‐diter‐butyl‐4‐hydroxyphenyl) propionic acid as raw material and dendritic poly(amidoamine) (PAMAM) as linker in chloroform. The antioxidant activities of the dendritic antioxidants were evaluated in polyolefin by melt flow index (MFI), yellowness index (Y.I.), and oxidation induction time (OIT). The dendritic antioxidants had excellent processing property and oxidation resistance behavior in polyolefin. At the same weighed amount of antioxidant, the MFI and Y.I. values of mulitiple‐extruded polyethylene (PE) stabilized with the dendritic antioxidants were smaller than those of the commercial antioxidants, as well as the OIT values of polyethylene (PE) stabilized with the dendritic antioxidants were larger. Applying to polypropylene, the antioxidant ability of the second‐generation dendritic antioxidant (G2.0 dendritic antioxidant) with larger molecular weight was superior to the commercial antioxidants and that of the first‐generation dendritic antioxidant (G1.0 dendritic antioxidant) was equal to the commercial antioxidants. The dendritic antioxidants can prevent polyolefin from breaking of macromolecular chain in processing and had stabilizing effect in polyolefin in service life by donating H‐atoms and electron to free radicals. The dendritic antioxidants combined with Irgafos 168 had improvement of antioxidant activities of the dendritic antioxidants in polyolefin. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Surface activities,biodegradability and antimicrobial properties of n-alkyl glucosides,mannosides and galactosides

n-Alkyl α-and β-glucopyranosides, α-D-mannopyranosides and β-D-galactopyranosides with alkyl chains having from 8 to 12 carbon atoms were synthesized and their surface properties-such as static surface tension (γ), critical micelle concentration (CMC), occupation area of molecule, dynamic surface tension and foaming properties, biodegradability and antimicrobial activities—were evaluated. Alkyl glycosides containing C8 to C12 carbon chains showed surface activities and critical micelle concentrations. D-Glucoside, D-mannoside and D-galactoside having the same alkyl chain showed similar surface tension lowering at CMC (γ_CMC) and occupation area of the molecule at the surface. Among the alkyl glucosides, α-anomers were less hydrophilic than β-anomers. All alkyl glycosides tested in this study were readily biodegraded by activated sludge of a municipal sewage plant compared to those of ethoxylated nonionic alcohols. The difference of the hydrophilic glycopyranoside group in biodegradability was not seen clearly. n-Alkyl glycosides containing C8 to C12 alkyl chains showed a broad spectrum of increasing antimicrobial activity. n-Dodecyl α-D-mannopyranoside was the most effective, the order of antimicrobial activity being mannopyranoside > glucopyranoside > galactopyranoside group. Members of this class of compounds exhibit the physicochemical and biological properties needed both for a wide range of applications and for environmental acceptance.     

Effects of Piptoporus betulinus Ethanolic Extract on the Proliferation and Viability of Melanoma Cells and Models of Their Cell Membranes

Piptoporus betulinus is a fungus known for its medicinal properties. It possesses antimicrobial, anti-inflammatory, and anti-cancer activity. In this study, several tests were performed to evaluate the cytotoxic effect of the ethanolic extract of Piptoporus betulinus on two melanoma human cell lines, WM115 primary and A375 metastatic cell lines, as well as Hs27 human skin fibroblasts. The extract proved to affect cancer cells in a dose-dependent manner, and at the same time showed a low cytotoxicity towards the normal cells. The total phenolic content (TPC) was determined spectrophotometrically by the Folin-Ciocalteu method (F-C), and the potential antioxidant activity was measured by ferric-reducing antioxidant power (FRAP) assay. One of the active compounds in the extract is betulin. It was isolated and then its cytotoxic activity was compared to the results obtained from the Piptoporus betulinus extract. To further understand the mechanism of action of the extract’s anticancer activity, tests on model cell membranes were conducted. A model membrane of a melanoma cell was designed and consisted of 1,2-dimyristoyl-sn-glycero-3-phosphocholine, disialoganglioside-GD_1a and cholesterol: DMPC:GD_1a:chol (5:2:3 mole ratio). Changes in a Langmuir monolayer were observed and described based on Π-A_mol isotherm and compressibility modulus changes. LB lipid bilayers were deposited on a hydrophilic gold substrate and analyzed by IR and X-ray photoelectron spectroscopy. Our study provides new data on the effect of Piptoporus betulinus extract on melanoma cells and its impact on the model of melanoma plasma membranes.     

Antioxidant and antitumor effects and immunomodulatory activities of crude and purified polyphenol extract from blueberries

The antioxidant and antitumor effects as well as the immunomodulatory activities of crude and purified polyphenol extract from blueberries were investigated. The antioxidant and antitumor effects of the polyphenol extract were measured both in vitro and in vivo, and their effect on the immune systems of CD-1 tumor-bearing mice were also analyzed. In vitro assays demonstrated that blueberry purified polyphenol extract (BBPP) exhibited higher antioxidant activities than blueberry crude polyphenol extract (BBCP), but the opposite effect was observed in vivo. Both the in vitro and in vivo antitumor activity and the immunity assay showed that BBCP not only inhibited tumor growth, but also significantly improved the immunity of the mice. According to physical and histological studies, the CD-1 tumor-bearing mice treated with the polyphenol extract, especially high doses of BBCP experienced a higher quality of life than the positive control group (treated with cyclophosphamide). These results indicate that BBCP has significant antioxidant and antitumor activities and that it can enhance the immunity of CD-1 tumor-bearing mice.

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Influence of Drying Temperature and Harvesting Season on Phenolic Content and Antioxidant and Antiproliferative Activities of Olive (Olea europaea) Leaf Extracts

Interest in plant compounds has increased, given recent evidence regarding their role in human health due to their pleiotropic effects. For example, plant bioactive compounds present in food products, including polyphenols, are associated with preventive effects in various diseases, such as cancer or inflammation. Breast and colorectal cancers are among the most commonly diagnosed cancers globally. Although appreciable advances have been made in treatments, new therapeutic approaches are still needed. Thus, in this study, up to 28 olive leaf extracts were obtained during different seasons and using different drying temperatures. The influence of these conditions on total polyphenolic content (measured using Folin–Ciocalteu assays), antioxidant activity (using Trolox Equivalent Antioxidant Capacity and Ferric Reducing Ability of Plasma assays) and antiproliferative capacity (using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, MTT assays) was tested in breast and colorectal cancer cells. Increased phenolic composition and antioxidant and antiproliferative capacity are noted in the extracts obtained from leaves harvested in autumn, followed by summer, spring and winter. Regarding drying conditions, although there is not a general trend, conditions using the highest temperatures lead to the optimal phenolic content and antioxidant and antiproliferative activities in most cases. These results confirm previously published studies and provide evidence in support of the influence of both harvesting and drying conditions on the biological activity of olive leaf extracts.     

防老剂TMQ的总氮含量测定

介绍防老剂TMQ总氮含量的测试步骤和数据处理方法。结果表明:本总氮含量测试方法有效;普通防老剂TMQ的总氮含量控制在7.2%～7.6%之间比较合适,高有效成分含量防老剂TMQ的最佳总氮含量范围需结合胶料性能确定。     

桑叶乙醇提取物的体外抗氧化与抑菌活性

采用索氏提取法对干桑叶进行提取,得到乙醇提取物,并对提取物的组分以及体外抗氧化活性和抑菌活性进行了测定。研究结果表明：桑叶乙醇提取物中含有多种有机物,主要包括酯类(82.85%)、烷烃类(6.31%)、芳烃类(1.62%)和醇类(0.21%)。桑叶乙醇提取物总还原力与浓度有显著的线性关系;对DPPH自由基和OH自由基都有良好的清除能力,半数抑制浓度(IC₅₀)分别为73.07和104.52 mg/L。桑叶乙醇提取物对枯草芽孢杆菌、金黄色葡萄球菌和大肠杆菌均具有一定的抑制作用,抑制效果为枯草芽孢杆菌＞金黄色葡萄球菌＞大肠杆菌,IC₅₀分别为4.824、6.806和14.382 g/L。桑叶乙醇提取物的抗氧化活性和抑菌活性随样品浓度的增大而增大。     

Total phenolic contents and antioxidant capacities of herbal and tea infusions

In order to supply new information on the antioxidant function of selected beverages for nutritionists and the general public, total phenolic contents of 51 kinds of herbal and tea infusions made in China were measured by the Folin-Ciocalteu method, and their antioxidant capacities were evaluated using ferric reducing antioxidant power (FRAP) and Trolox equivalent antioxidant capacity (TEAC) assays. A significant correlation between FRAP and TEAC values suggested that antioxidant components in these beverages were capable of reducing oxidants and scavenging free radicals. The high correlation between antioxidant capacities and total phenolic contents indicated that phenolic compounds could be one of the main components responsible for antioxidant activities of these beverages. Generally, these beverages had high antioxidant capacities and total phenolic contents, and could be important dietary sources of antioxidant phenolics for prevention of diseases caused by oxidative stress.     

虎杖中抗氧化成分的提取分离及其活性研究

提取了虎杖中具有抗氧化活性的总蒽醌(TA),并从总蒽醌中依次分离出强酸成分(SAP)、中酸成分(MAP)和弱酸成分(WAP)。然后采用二苯代苦味酰自由基(DPPH)法对不同质量浓度的TA、SAP、MAP和WAP进行了抗氧化活性测定。TA、SAP、MAP和WAP质量浓度分别为0.2 g/L、0.5 g/L、0.8 g/L、1.2 g/L时,对自由基的最大清除率依次分别为:29.5%、67.1%、85.7%、87.5%;34.0%、74.2%、86.5%、95.4%;9.8%、24.0%、35.2%、47.3%;6.5%、11.1%、19.6%、19.9%。TA、SAP、MAP和WAP对自由基均有程度不同的清除作用,其中SAP的效果最佳,当其质量浓度为1.2 g/L时,最大清除率可高达95.4%。     

Antioxidant and Antimicrobial Activities of Echinacea (Echinacea purpurea L.) Extracts Obtained by Classical and Ultrasound Extraction

Antioxidant and antimicrobial activities of Echinacea purpurea L. (Asteraceae) extracts obtained by classical and ultrasound solvent extraction were compared. The dry aerial part of plant was extracted by 70% ethanol at a solid-to-liquid ratio of 1:10 (m/v) and 25°C. The extract obtained by classical solvent extraction contained 29% larger amounts of phenolic compounds and 20% higher content of flavonoids. 2,2-diphenyl-1-picril hydrazyl radical (DPPH) scavenging reached 93.6% and the values of EC50 were (34.16±0.65) μg·ml⁻¹ and (65.48±1.12) μg·ml⁻¹ for the extracts obtained by the classical and ultrasound extractions, respectively. The extracts, independent of the extraction technique applied, showed a considerable growth inhibition on Candida albicans and Saccharomyces cerevisiae, while no growth inhibition zones were observed for Aspergillus niger. The diameters of inhibition zone observed for all the microorganisms were larger for extracts obtained by classical extraction than those by ultrasound extraction.