Isolation and antioxidant activity evaluation of two new phthalate derivatives from seahorse, Hippocampus Kuda Bleeler

Seahorse (Hippocampus Kuda Bleeler) has been used as traditional medicine for thousands of years, in Eastern Asia. In this study of the methanol extract of fresh Hippocampus Kuda, the new compounds 2-ethyldecyl 2-ethylundecyl phthalate (1), 2, 12-diethyl-11-methylhexadecyl 2-ethyl-11-methylhexadecylphthalate (2), along with a known Bis(2-ethylheptyl) phthalate (3) were isolated. They were tested for their antioxidant activities, including lipid peroxidation inhibitory activity, DPPH radical scavenging, hydroxyl radical scavenging, superoxide anion radical scavenging, alkyl radical scavenging, and cellular radicals; these can be detected using a fluorescence probe, 2??,7??-dichlorofluorescin diacetate (DCFH-DA), which could be converted to highly fluorescent dichlorofluorescein (DCF) with the presence of intracellular ROS on mouse macrophages, RAW264.7 cell. Compound (2) exhibited the highest antioxidant activity and inhibitory intracellular ROS than another compounds (1, 3). Furthermore, MTT assay showed no cytotoxicity on mouse macrophages cell (RAW264.7) and human fetal lung fibroblast cell line (MRC-5). This antioxidant property depends on concentration and increasing with increased amount of the compound.     

IN VITRO ANTIOXIDANT ACTIVITIES OF THE FERMENTED MARINE MICROALGA PAVLOVA LUTHERI (HAPTOPHYTA) WITH THE YEAST HANSENULA POLYMORPHA1

Microalgae are major primary producers of organic matter in aquatic environments through their photosynthetic activities. Fermented microalga (Pavlova lutheri Butcher) preparation (FMP) is the product of yeast fermentation by Hansenula polymorpha. It was tested for the antioxidant activities including lipid peroxidation inhibitory activity, free‐radical‐scavenging activity, inhibition of reactive oxygen species (ROS) on mouse macrophages (RAW264.7 cell), and inhibited myeloperoxidase (MPO) activity in human myeloid cells (HL60). FMP exhibited the highest antioxidant activity on free‐radical scavenging, inhibitory intracellular ROS, and inhibited MPO activity. MTT [3‐(4,5‐dimethyl‐2‐yl)‐2,5‐diphenyltetrazolium bromide] assay showed no cytotoxicity in mouse macrophages (RAW264.7 cell), human myeloid cells (HL60), and human fetal lung fibroblast cell line (MRC‐5). Furthermore, the antioxidative mechanism of FMP was evaluated by protein expression levels of antioxidant enzyme (superoxide dismutase [SOD] and glutathione [GSH]) using Western blot. The results obtained in the present study indicated that FMP is a potential source of natural antioxidant.     

Inhibition of free radical-mediated oxidation of cellular biomolecules by carboxylated chitooligosaccharides

The objective of this study was to identify the cellular antioxidant effects of carboxylated chitooligosaccharides (CCOS), a chemically modified derivative of chitooligosaccharides (COS), by assessing oxidation inhibition potential on cellular biomolecules such as lipids, proteins, and direct scavenging of reactive oxygen species (ROS). Radical-mediated oxidation of cell membrane lipids and proteins was dose-dependently inhibited by CCOS, assessed by amount of lipid hydroperoxides and carbonyl carbon content in mouse macrophages, RAW264.7 cells. Further, CCOS inhibited myeloperoxidase (MPO) activity in human myeloid cells (HL60) suggesting indirect possibility of inhibiting generation of reactive oxygen species (ROS) such as superoxide radicals, H(2)O(2) and HOCl. Direct radical scavenging studies carried out with DCFH-DA fluorescence probe concluded that CCOS can act as a potent radical scavenger in cells.     

The influence of wine polyphenols on reactive oxygen and nitrogen species production by murine macrophages RAW 264.7

The aim was to study the antioxidant properties of four wine polyphenols (flavonoids catechin, epicatechin, and quercetin, and hydroxystilbene resveratrol). All three flavonoids exerted significant and dose-dependent scavenging effects against peroxyl radical and nitric oxide in chemical systems. The scavenging effect of resveratrol was significantly lower. All polyphenols decreased production of reactive oxygen species (ROS) by RAW264.7 macrophages. Only quercetin quenched ROS produced by lipopolysaccharide-stimulated RAW264.7 macrophages incubated for 24 h with polyphenols. Quercetin and resveratrol decreased the release of nitric oxide by these cells in a dose-dependent manner which corresponded to a decrease in iNOS expression in the case of quercetin. In conclusion, the higher number of hydroxyl substituents is an important structural feature of flavonoids in respect to their scavenging activity against ROS and nitric oxide, while C-2,3 double bond (present in quercetin and resveratrol) might be important for inhibition of ROS and nitric oxide production by RAW 264.7 macrophages.     

The in vitro anti-platelet,antioxidant and cellular immunity activity of <Emphasis Type="Italic">Phellinus gilvus</Emphasis> fractional extracts

The in vitro anti-platelet and antioxidant activities of various solvent extracts from Phellinus gilvus (PG), and the effects of hot water extract from PG (PGW) on murine cellular immunity were investigated. Chloroform extract (CE), methanol extract (ME) and butanol extract (BE) from PG could significantly inhibit platelet aggregation induced by thrombin. Ethyl acetate extract (EAE), BE, ME from PG had significant 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity compared with the control, and the EAE showed the highest effect with IC₅₀ values of 13.34 μg/ml, which is higher than that of ascorbic acid (40 μg/ml). In addition, EAE displayed the inhibition of xanthine oxidase (XO) activity with IC₅₀ value of 2.45 μg/ml. As to the cellular immunity activity, PGW could enhance both the lipopolysaccharide (LPS)-induced B lymphocyte proliferation and concanavalin A (Con A)-induced T lymphocyte proliferation in vitro. The phagocytosis of both peritoneal macrophages and RAW264.7 macrophage cells were also increased by the addition of PGW. Moreover, PGW was found to inhibit the nitric oxide (NO) production of RAW264.7 macrophages induced by LPS in a concentration-dependant manner.     

Evaluation of antioxidant activity of <Emphasis Type="Italic">Melothria maderaspatana in vitro</Emphasis>

In this study, an aqueous extract of leaves from Melothria maderaspatana was tested for in vitro antioxidant activity. Free radical scavenging assays, such as hydroxyl radical, hydrogen peroxide, superoxide anion radical and 2,2-diphenyl-1-picryl hydrazyl (DPPH), 2,2’-azinobis-(3-ethyl-enzothiazoline-6-sulfonic acid) (ABTS) radical scavenging, and reducing power assay, were studied. The extract effectively scavenged hydroxyl radical, hydrogen peroxide and superoxide anion radicals. It also scavenged DPPH and ABTS radicals. Furthermore, it was found to have reducing power. All concentrations of leaf extract exhibited free radical scavenging and antioxidant power, and the preventive effects were in a dose-dependent manner. The antioxidant activities of the above were compared to standard antioxidants such as butylated hydroxytoluene (BHT), ascorbic acid, and α-tocopherol. The results obtained in the present study indicate that the M. maderaspatana extract could be considered a potential source of natural antioxidant.     

Chitosan gallate as potential antioxidant biomaterial

Chitosan gallate were synthesized using a free radical-induced grafting reaction. Chitosan gallate showed enhanced water-solubility compared to plain chitosan, and exhibited good thermal stability. The IC₅₀ value of chitosan gallate against 2,2-diphenyl-1-picrylhydrazyl (DPPH) was 17.86 μg/mL. In addition, chitosan gallate effectively inhibited the generation of intracellular reactive oxygen species (ROS), and also suppressed lipid peroxidation in RAW264.7 macrophage cells. Chitosan gallate also exhibited the protection effect on genomic DNA damage by induced hydroxyl radical, and up-regulated the protein expression of antioxidant enzymes including superoxide dismutase-1 and glutathione reductase under H₂O₂-mediated oxidative stress in RAW264.7 macrophage cells. These results indicate that chitosan gallate might be potential antioxidant biomaterials.     

Antioxidant Effects of Rhodoxanthin from Potamogeton crispus L. on H2O2-Induced RAW264.7 Macrophages Cells

Potamogeton crispus L. (P. crispus) is the type of a widely distributed perennial herbs, which is rich in rhodoxanthin. In this research work, five antioxidant indexes in vitro were selected to study the antioxidant activity of rhodoxanthin from P. crispus (RPC). A model of hydrogen peroxide (H₂O₂) -induced oxidative damage in RAW264.7 cells was established to analyze the antioxidant effect and potential mechanism of RPC. The levels of ROS, MDA and the activities of oxidation related enzymes by H₂O₂ were determined by enzyme linked immunosorbent assay (ELISA). The mRNA expression of Nrf-2, HO-1, SOD1 and SOD2 was measured by qRT-PCR assay. According to the results, RPC had free radical scavenging ability for 2, 2-diphenyl-1-trinitrohydrazine (DPPH), 2,2’-azinobis(3-ethylbenzo-thiazoline-6-sulfonic acid radical ion) (ABTS), hydroxyl radical and superoxide anion. RPC significantly decreased the level of MDA and ROS and LDH activity, while increased GSH level and activities of SOD, GSH−Px and CAT. It was showed that RPC could increase the mRNA expression of Nrf-2, HO-1, SOD1 and SOD2 in RAW264.7 cells in a dose-dependently manner. In summary, RPC treatment could effectively attenuate the H₂O₂-induced cell damage rate, and the mechanism is related to the reduction of H₂O₂ induced oxidative stress and the activation of Nrf-2 pathway.     

Ishigoside, a new glyceroglycolipid isolated from the brown alga Ishige okamurae

A new glyceroglycolipid, ishigoside (1, 2-di-O-palmitoyl-3-O-(6-deoxy-6-amino)-α-D-glucopyranosyl-glycerol, 1), along with two known compounds were isolated from the brown alga Ishige okamurae. The structure of the new compound was determined on the basis of spectroscopic analysis, including 1D and 2D NMR, MS techniques and chemical methods. Moreover, direct free radical scavenging activities of ishigoside were investigated by electron spin resonance spectrometry (ESR) technique. The results suggested that ishigoside was a potential free-radical scavenger against DPPH, hydroxyl, alkyl, and superoxide radicals with the EC₅₀ of 31.2, 16.7, 22.7, and 26.8 μM, respectively.     

3种百合鳞茎中多酚类物质的抗氧化活性分析

以野生百合渥丹、山丹和传统食用的兰州百合为研究对象,对其鳞茎中多酚类物质、11种单体酚的含量及抗氧化活性(ABTS自由基、超氧阴离子、羟自由基的清除能力,铜离子还原能力以及抑制脂质过氧化活性)进行了分析。结果表明:两种野生百合鳞茎中的多酚类物质含量及抗氧化活性均显著高于兰州百合。3种百合鳞茎中单体酚的种类也有所不同,但均含有没食子酸、矢车菊素-3-芸香糖苷、儿茶素、表儿茶素、杨梅酮、芦丁、对香豆酸、山奈酚。相关性分析显示,除对羟自由基的清除力外,各酚类物质总量与不同抗氧化指标之间呈显著正相关关系。试验结果认为,野生百合鳞茎可作为天然抗氧化资源应用于食品和医药业,具有一定的开发应用前景。     

桦褐孔菌提取物抗氧化活性研究

以乙酸乙酯和甲醇为提取剂,采用索氏提取法,剩余残渣采用热水浸提,最终得到桦褐孔菌不同极性提取物,对其DPPH自由基、羟基自由基及超氧阴离子自由基清除活性作用进行了研究,确定桦褐孔菌的抗氧化能力,为深入研究和开发桦褐孔菌功能性食品奠定理论基础。实验结果表明桦褐孔菌具有较好的抗氧化活性,其中乙酸乙酯提取物的DPPH自由基清除率、羟基自由基清除率和超氧阴离子自由基清除率均高于其他两组分及BHT,桦褐孔菌提取物有望成为功能性食品组分中合成抗氧化剂的天然替代品。     

In vitro and in vivo antioxidant activity of exopolysaccharide fractions from Bifidobacterium animalis RH

The aim of the study was to purify the exopolysaccharides (EPS) produced from Bifidobacterium animalis RH, which was isolated from the feces of Bama centenarians in Guangxi of China, and evaluate their antioxidant activities in vitro and in vivo. 2 fractions, a neutral EPS fraction (EPSa) and an acidic EPS fraction (EPSb), were obtained and compared for antioxidative activity. In vitro, they both showed remarkable inhibition effect on lipid peroxidation and strong DPPH radical scavenging activity, hydroxyl radical scavenging activity, superoxide radical scavenging activity, in which the last two were measured by the electron spin resonance (ESR). In vivo, EPSa and EPSb were orally administrated for 30 days in a d-galactose induced aged mice model. As results, they both could significantly increase the activities of SOD, CAT and total antioxidant capacity (TAOC) in serums and glutathione GST in livers. They also could inhibit significantly the formation of MDA in serums and livers, and reduce the activity of MAO and lipofuscin accumulation in mice brain. Moreover, EPSb exhibited much higher antioxidant activities than EPSa in vitro and in vivo. The results suggested that EPS fractions of Bifidobacterium animalis RH had direct and potent antioxidant activities.     

Antioxidant and Neuroprotective Activities of Mogami-benibana (Safflower,Carthamus tinctorius Linne)

Free radical scavenging activity of the extracts of petals (bud, early stage, full blooming and ending stage), leaf, stem, root and seeds of Mogami-benibana (safflower, Carthamus tinctorius Linne), the contents of the major active components of carthamin and polyphenols, and neuroprotective effect of the petal extracts and carthamin in the brain of mice and rats were examined. Water extracts of Mogami-benibana petals scavenged superoxide, hydroxyl and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and singlet oxygen. The scavenging activities of the extract of safflower petals with various colors showed the order of orange, yellow and white from high to low. This order is consistent with the contents of carthamin, which is a pigment of orange color and is found highest in orange petals and lowest in white petals. There was also a relationship between DPPH radical scavenging activity and carthamin content in the petal extracts of safflower. The neuroprotective effects were examined in cellular and animal models. Mogami-benibana petal extract inhibited glutamate-induced C6 glia cell death, significantly decreased the formation of malondialdehyde in mouse cerebrum, and inhibited the increase in thiobarbituric acid reactive substances and 8-hydroxy-2′-deoxyguanosine (8-OHdG) in the cerebral cortex of rats subjected to an injection of FeCl₃ solution into the sensory motor cortex. Carthamin showed similar effects in inhibiting 8-OHdG by the petal extract in rats. These results suggest that the petal extract of Mogami-benibana has free radical scavenging activity and neuroprotective effect and carthamin is one of the major active components. Special Issue Article in Honor of Dr. Akitane Mori.     

Protective effects of aminoethyl-chitooligosaccharides against oxidative stress in mouse macrophage RAW 264.7 cells

The aim of this study is to investigate the inhibitory effects of aminoethyl-chitooligosaccharides (AE-COS) on oxidative stress in mouse macrophages (RAW 264.7 cells). The inhibitory effects of AE-COS on DNA and protein oxidation were studied in RAW 264.7 cells. Furthermore, free radical scavenging effect of AE-COS were determined in RAW264.7 cells by 2',7'-dichlorofluorescein (DCF) intensity and intracellular glutathione (GSH) level. AE-COS also inhibited myeloperoxidase (MPO) activity in human myeloid cells (HL-60). These results suggest that AE-COS acts as a potential free radical scavenger in RAW 264.7 cells.     

Dandelion (Taraxacum officinale) flower extract suppresses both reactive oxygen species and nitric oxide and prevents lipid oxidation in vitro

Flavonoids and coumaric acid derivatives were identified from dandelion flower (Taraxacum officinale). Characteristics of chain-breaking antioxidants, such as extended lag phase and reduced propagation rate, were observed in oxidation of linoleic acid emulsion with the addition of dandelion flower extract (DFE). DFE suppressed both superoxide and hydroxyl radical, while the latter was further distinguished by both site-specific and non-specific hydroxyl radical inhibition. DPPH-radical-scavenging activity and a synergistic effect with alpha-tocopherol were attributed to the reducing activity derived from phenolic content of DFE. A significant (p < 0.05) and concentration-dependent, reduced nitric oxide production from acterial-lipopolysaccharide-stimulated mouse macrophage RAW264.7 cells was observed with the addition of DFE. Moreover, peroxyl-radical-induced intracellular oxidation of RAW264.7 cells was inhibited significantly (p < 0.05) by the addition of DFE over a range of concentrations. These results showed that the DFE possessed marked antioxidant activity in both biological and chemical models. Furthermore, the efficacy of DFE in inhibiting both reactive oxygen species and nitric oxide were attributed to its phenolic content.     

Antioxidative and cytoprotective effects of Artemisia capillaris fractions

The antioxidant effects of Artemisia capillaris fractions against reactive oxygen species (ROS) were evaluated by measuring scavenging activities against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, superoxide (O_2(-)), hydroxyl (HO.) and nitric oxide (NO.) radical. Among five solvent fractions, ethyl acetate fraction showed the highest total polyphenol and total flavonoid contents as 648.75 and 89.09 microg/mg, respectively. Also, the ethyl acetate fraction showed the highest scavenging activity; the 50% inhibitory concentration (IC50, microg/mg) value for DPPH, O_2(-), HO. and NO. radical scavenging were 4.76, 31.54, 69.34 and 74.63, respectively. Additionally, the highest inhibition of rat liver microsomal lipid peroxidation was observed by ethyl acetate fraction. Except for free radical-mediated protein damage, ethyl acetate fraction showed the highest scavenging activity. The effect of Artemisia capillaris fractions on cell viability and DNA damage induced by H2O2 in Raw 264.7 cell were also evaluated by MTT and comet assay, respectively. The protective effect of ethyl acetate fraction, as indicated by cell viability increasing 71% and DNA breakage decreasing 51% as compared with H2O2-treated positive control. These results suggest that ethyl acetate fraction possess significant ROS scavenging and protective effect against oxidative DNA damage.     

Antioxidant activities of phlorotannins isolated from Japanese Laminariaceae

The antioxidant activities of brown algal phlorotannins were evaluated using the inhibition of phospholipid peroxidation in the liposome system, and by determining radical scavenging activities against the superoxide anion and 1,1-diphenyl-2-picrylhydrazyl (DPPH). Oligomers of phloroglucinol (1,3,5-trihydroxybenzene), eckol (a trimer), phlorofucofuroeckol A (a pentamer), dieckol and 8,8′-bieckol (hexamers), isolated from the Laminarian brown algae Eisenia bicyclis, Ecklonia cava and Ecklonia kurome, showed potent inhibition of phospholipid peroxidation at 1 μM in the liposome system. The phlorotannins had significant radical scavenging activities against the superoxide anion (50% effective concentration values: 6.5–8.4 μM) and DPPH (50% effective concentration values: 12–26 μM), and were more effective compared to ascorbic acid and α-tocopherol. For the purpose of using phlorotannins as functional food ingredients, the antioxidant activity of a complex of crude phlorotannins and soybean protein was examined. The complex had a pronounced DPPH-radical scavenging activity. These results suggest that phlorotannins are potent anti-inflammatory substances, and that the Laminariaceous brown algae, which are abundant in phlorotannins, may be useful as a new functional foodstuff or supplement with anti-inflammatory activity.     

Isolation and characterization of dihydromonacolin-MV from <Emphasis Type="Italic">Monascus purpureus</Emphasis> for antioxidant properties

The methanolic extract of Monascus purpureus cultivated by solid-state fermentation on rice showed strong 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and better yield as compared to other polarity based extracted fractions. It was selected for further purification of the antioxidant. The activity-guided repeated fractionation of methanolic extract on a silica gel column chromatography yielded a compound that exhibited strong antioxidant activity. Based on the spectroscopic analysis by UV, IR, ¹H NMR, ¹³C NMR, 2D-HSQCT NMR, and MS, the antioxidant isolated was elucidated as a derivative of dihydromonacolin-K, where the ester group is 2-methyl propionate, designated as dihydromonacolin-MV. The DPPH radical was significantly scavenged by the dihydromonacolin-MV (IC₅₀ 20±1 μg ml⁻¹). The dihydromonacolin-MV showed strong inhibition of lipid peroxidation in a liposome model with an IC₅₀ value of 5.71±0.38 μg ml⁻¹ and superoxide radical scavenging activity with an IC₅₀ value of 163.97±2.68 μg ml⁻¹.     

Oxygen radical scavenging capacity of phenolic and non-phenolic compounds in red and white wines

The aim of the present study was the evaluation of the antioxidant content in phenolic and non-phenolic extracts of ten wine samples, trying to elucidate the potential role of unusual antioxidant compounds. Samples of wines processed from red and white grapes (Vitis vinifera L.), deprived of the volatile fraction at low temperature and buffered at physiological pH, were fractionated by C₁₈ into two fractions: FR1 and FR2. Non-phenolics, such as tartaric, malic, lactic, and succinic acids; glucose; fructose; and glycerin were mainly found in FR1, while polyphenols were present exclusively in FR2. Peroxyl radical quenching was assayed by the ORAC method, while superoxide and hydroxyl radical scavenging activity were assayed by electron paramagnetic resonance. In the ORAC and superoxide assays, most of the activity was found in FR2, while in hydroxyl radical assay, the activity was found in FR1. Model solutions were used to attribute a role to the single compounds in the evaluation of wine’s ROS scavenging capacity: the ORAC and superoxide anion scavenging effects were mainly attributed to the polyphenols, averaging 94.8%, with some contribution from glycerin, particularly in white wines. Unexpectedly, the main chemical responsible for hydroxyl radical scavenging activity was glycerin (56.1%), with the polyphenols scavenging at 18.1%.     

绣球菌多糖表征及其抗氧化和免疫活性

提取纯化绣球菌多糖(Sparassis latifolia polysaccharides,SCPs),研究其表征和功能活性,探索绣球菌多糖表征与其抗氧化及免疫活性之间的关系。以绣球菌子实体为原料,采用聚能超声波辅助水提醇沉法提取绣球菌多糖,经DEAE-52、SephadexG-100纯化,用高效凝胶渗透色谱法、离子色谱法、傅里叶红外色谱法、扫描电镜、原子力显微镜对绣球菌多糖进行初步表征,检测绣球菌多糖清除DPPH、·OH、O2^-·自由基能力以及总还原力,用MTT法检测绣球菌多糖对巨噬细胞RAW264.7增殖的影响。结果表明,SCPs分子量范围为215Da–393kDa,由葡萄糖、甘露糖、半乳糖、木糖、果糖构成,摩尔比13:4:1:2:3,其表观形貌为簇状堆积,交织,结构规律性不强,表面光滑,呈一定的网络状结构,分子呈现链状构象,具有高度的分支结构,链间形成小环且伴随一定的球形颗粒。SCPs具有一定的还原能力和清除DPPH、·OH、O2^-·自由基的能力,且能够促进巨噬细胞RAW264.7的增殖。绣球菌多糖的抗氧化及免疫活性可能与其分子量、单糖组成、糖链分支及分子构象有关。