Fucoidans as Potential Inhibitors of HIV-1

The antiviral activity of different structure fucoidans (α-l-fucans and galactofucans) was studied using two model viral systems based on a lentiviral vectors and a replication competent Moloney murine leukemia virus (Mo-MuLV). It was found that investigated fucoidans have no cytotoxic effects on Jurkat and SC-1cell at the concentration range of 0.001–100 µg/mL. Fucoidans with different efficiency suppressed transduction of Jurkat cell line by pseudo-HIV-1 particles carrying the envelope protein of HIV-1 and infection of SC-1 cells by Mo-MuLV. According to our data, all natural fucoidans can be considered as potential anti-HIV agents regardless of their carbohydrate backbone and degree of sulfating, since their activity is shown at low concentrations (0.001–0.05 µg/mL). High molecular weight fucoidans isolated from Saccharina cichorioides (1.3-α-l-fucan), and S. japonica (galactofucan) were the most effective inhibitors.     

Important determinants for fucoidan bioactivity: a critical review of structure-function relations and extraction methods for fucose-containing sulfated polysaccharides from brown seaweeds

Seaweeds--or marine macroalgae--notably brown seaweeds in the class Phaeophyceae, contain fucoidan. Fucoidan designates a group of certain fucose-containing sulfated polysaccharides (FCSPs) that have a backbone built of (1→3)-linked α-L-fucopyranosyl or of alternating (1→3)- and (1→4)-linked α-L-fucopyranosyl residues, but also include sulfated galactofucans with backbones built of (1→6)-β-D-galacto- and/or (1→2)-β-D-mannopyranosyl units with fucose or fuco-oligosaccharide branching, and/or glucuronic acid, xylose or glucose substitutions. These FCSPs offer several potentially beneficial bioactive functions for humans. The bioactive properties may vary depending on the source of seaweed, the compositional and structural traits, the content (charge density), distribution, and bonding of the sulfate substitutions, and the purity of the FCSP product. The preservation of the structural integrity of the FCSP molecules essentially depends on the extraction methodology which has a crucial, but partly overlooked, significance for obtaining the relevant structural features required for specific biological activities and for elucidating structure-function relations. The aim of this review is to provide information on the most recent developments in the chemistry of fucoidan/FCSPs emphasizing the significance of different extraction techniques for the structural composition and biological activity with particular focus on sulfate groups.     

Physicochemical and Biological Characterization of Fucoidan from Fucus vesiculosus Purified by Dye Affinity Chromatography

A comparative study concerning the physicochemical, monomeric composition and biological characters among different fucoidan fractions is presented. Common purification techniques for fucoidan usually involve many steps. During these steps, the important structural features might be affected and consequently alter its biological activities. Three purified fractions were derived from Fucus vesiculosus water extract which, afterwards, were purified by a recently-developed dye affinity chromatography protocol. This protocol is based on dye-sulfated polysaccharide interactions. The first two fractions were obtained from crude precipitated fucoidan at different pH values of the adsorption phase: pH 1 and 6. This procedure resulted in fucoidan_1 and 6 fractions. The other, third, fraction: fucoidan_M, however, was obtained from a buffered crude extract at pH 1, eliminating the ethanol precipitation step. All of the three fractions were then further evaluated. Results revealed that fucoidan_M showed the highest sulfur content (S%), 12.11%, with the lowest average molecular weight, 48 kDa. Fucose, galactose, and uronic acid/glucose dimers were detected in all fractions, although, xylose was only detected in fucoidan_1 and 6. In a concentration of 10 µg·mL⁻¹, Fucoidan_6 showed the highest heparin-like anticoagulant activity and could prolong the APTT and TT significantly to 66.03 ± 2.93 and 75.36 ± 1.37 s, respectively. In addition, fucoidan_M demonstrated the highest potency against HSV-1 with an IC₅₀ of 2.41 µg·mL⁻¹. The technique proved to be a candidate for fucoidan purifaction from its crude extract removing the precipitation step from common purification protocols and produced different fucoidan qualities resulted from the different incubation conditions with the immobilized thiazine toluidine blue O dye.     

Perspective on the Use of Sulfated Polysaccharides from Marine Organisms as a Source of New Antithrombotic Drugs

Thromboembolic diseases are increasing worldwide and always require anticoagulant therapy. We still need safer and more secure antithrombotic drugs than those presently available. Sulfated polysaccharides from marine organisms may constitute a new source for the development of such drugs. Investigation of these compounds usually attempts to reproduce the therapeutic effects of heparin. However, we may need to follow different routes, focusing particularly in the following aspects: (1) defining precisely the specific structures required for interaction of these sulfated polysaccharides with proteins of the coagulation system; (2) looking for alternative mechanisms of action, distinct from those of heparin; (3) identifying side effects (mostly pro-coagulant action and hypotension rather than bleeding) and preparing derivatives that retain the desired antithrombotic action but are devoid of side effects; (4) considering that sulfated polysaccharides with low anticoagulant action on in vitro assays may display potent effects on animal models of experimental thrombosis; and finally (5) investigating the antithrombotic effect of these sulfated polysaccharides after oral administration or preparing derivatives that may achieve this effect. If these aspects are successfully addressed, sulfated polysaccharides from marine organisms may conquer the frontier of antithrombotic therapy and open new avenues for treatment or prevention of thromboembolic diseases.     

Effect of Fucoidan Extracted from Mozuku on Experimental Cartilaginous Tissue Injury

We investigated the effect of fucoidan, a sulfated polysaccharide, on acceleration of healing of experimental cartilage injury in a rabbit model. An injured cartilage model was surgically created by introduction of three holes, one in the articular cartilage of the medial trochlea and two in the trochlear sulcus of the distal femur. Rabbits in three experimental groups (F groups) were orally administered fucoidan of seven different molecular weights (8, 50, 146, 239, 330, 400, or 1000 kD) for 3 weeks by screening. Control (C group) rabbits were provided water ad libitum. After the experimental period, macroscopic examination showed that the degree of filling in the fucoidan group was higher than that in the C group. Histologically, the holes were filled by collagen fiber and fibroblasts in the C group, and by chondroblasts and fibroblasts in the F groups. Image analysis of Alcian blue- and safranin O-stained F-group specimens showed increased production of glycosaminoglycans (GAGs) and proteoglycans (PGs), respectively. Some injured holes were well repaired both macroscopically and microscopically and were filled with cartilage tissues; cartilage matrices such as PGs and GAGs were produced in groups F 50, F 146, and F 239. Thus, fucoidan administration enhanced morphologically healing of cartilage injury.     

茶多糖的化学修饰及体外抗凝血作用研究

采用DEAE-52纤维素柱层析的方法,分离纯化乌龙茶中的多糖成分;选用硫酸化、乙酰化和羧甲基化分别对纯化后的茶多糖进行化学修饰,研究了其修饰前后的体外抗凝血作用。结果表示:茶多糖具有抗凝血作用,能显著延长人体血浆的APTT值,而对TT和PT值无明显影响。茶多糖经柱层析后分离出四个多糖组分,其中组分Ⅱ为茶多糖总量的57.36%,抗凝血活性也相对较强。茶多糖组分Ⅱ经硫酸化、乙酰化和羧甲基化修饰后,抗凝血活性进一步增强,化学修饰试剂与多糖的比例以及修饰反应时间在一定的范围内,影响茶多糖分子结构的变化程度,相应改变抗凝血活性。     

根瘤菌对生态农业的重要意义及其影响因素

LI Ling(Liaoning Economic Crop Institute, Liaoyang, Liaoning 111000)     

铝胁迫对花生根系的影响

花生发芽期、苗期和成熟期的根系性状研究表明,铝胁迫对花生根系的生长发育有较大的影响,Ａｌ＾３＋含量与胚根和胚轴的伸长呈显著负相关,不同基因型根系受铝毒危害有明显差异,耐铝基因型可能在根际形成ｐＨ障碍。早期直接测定花生根系性状指标,有助于评价和筛选耐铝毒材料。     

Effects of Chitin and Sepia Ink Hybrid Hemostatic Sponge on the Blood Parameters of Mice

Chitin and sepia ink hybrid hemostatic sponge (CTSH sponge), a new biomedical material, was extensively studied for its beneficial biological properties of hemostasis and stimulation of healing. However, studies examining the safety of CTSH sponge in the blood system are lacking. This experiment aimed to examine whether CTSH sponge has negative effect on blood systems of mice, which were treated with a dosage of CTSH sponge (135 mg/kg) through a laparotomy. CTSH sponge was implanted into the abdominal subcutaneous and a laparotomy was used for blood sampling from abdominal aortic. Several kinds of blood parameters were detected at different time points, which were reflected by coagulation parameters including thrombin time (TT), prothrombin time (PT), activated partial thromboplatin time (APTT), fibrinogen (FIB) and platelet factor 4 (PF4); anticoagulation parameter including antithrombin III (AT-III); fibrinolytic parameters including plasminogen (PLG), fibrin degradation product (FDP) and D-dimer; hemorheology parameters including blood viscosity (BV) and plasma viscosity (PV). Results showed that CTSH sponge has no significant effect on the blood parameters of mice. The data suggested that CTSH sponge can be applied in the field of biomedical materials and has potential possibility to be developed into clinical drugs of hemostatic agents.     

甜菜种子发芽率变动规律及影响因子初探

对甜菜种子发芽率变动规律及影响因子分析表明,二倍体甜菜种子发芽率高于多倍体甜菜,且样本间变异系数大;中粒型种球即可满足育种及用种单位对发芽率的要求;正常情况下黄或黄褐色种球发芽率高于黑褐色种球;于种子休眠期可测得准确发芽率;“挖心”去顶端优势法种子发芽率高于“打顶”法;此外合理的栽培措施及肥水运筹均可提高种子发芽率。     

Production of a Novel Fucoidanase for the Green Synthesis of Gold Nanoparticles by Streptomyces sp. and Its Cytotoxic Effect on HeLa Cells

Marine actinobacteria-produced fucoidanases have received considerable attention as one of the major research topics in recent years, particularly for the medical exploitation of fucoidans and their degradation products. The present study describes the optimization and production of a novel fucoidanase for the green synthesis of gold nanoparticles and its biological applications. The production of fucoidanase was optimized using Streptomyces sp. The medium components were selected in accordance with the Plackett-Burman design and were further optimized via response surface methodology. The fucoidanase was statistically optimized with the most significant factors, namely wheat bran 3.3441 g/L, kelp powder 0.7041 g/L, and NaCl 0.8807 g/L, respectively. The biosynthesized gold nanoparticles were determined by UV-vis spectroscopy and were further characterized by X-ray diffraction analysis, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, energy dispersive X-ray analysis, and high-resolution transmission electron microscopy. Furthermore, the biosynthesized gold nanoparticles exhibited a dose-dependent cytotoxicity against HeLa cells and the inhibitory concentration (IC₅₀) was found to be 350 µg/mL at 24 h and 250 µg/mL at 48 h. Therefore, the production of novel fucoidanase for the green synthesis of gold nanoparticles has comparatively rapid, less expensive and wide application to anticancer therapy in modern medicine.     

NaCl和NaHCO3胁迫对玉米幼苗根系的影响

用不同浓度NaCl和NaHCO3处理玉米幼苗,研究其根系活力、伤害率、根系生长情况与地上部的关系,以探讨玉米的抗盐机理。实验结果表明：随着盐浓度的升高,根系和地上部的生长显著降低;根系体积均低于对照,根系活力、伤害率均高于对照,呈上升趋势。     

Effects of Oral Administration of Fucoidan Extracted from Cladosiphon okamuranus on Tumor Growth and Survival Time in a Tumor-Bearing Mouse Model

We evaluated the anti-tumor activities of the oral administration of fucoidan extracted from Cladosiphon okamuranus using a tumor (colon 26)-bearing mouse model. The materials used included low-molecular-weight fucoidan (LMWF: 6.5–40 kDa), intermediate-molecular-weight fucoidan (IMWF: 110–138 kDa) and high-molecular-weight fucoidan (HMWF: 300–330 kDa). The IMWF group showed significantly suppressed tumor growth. The LMWF and HMWF groups showed significantly increased survival times compared with that observed in the control group (mice fed a fucoidan-free diet). The median survival times in the control, LMWF, IMWF and HMWF groups were 23, 46, 40 and 43 days, respectively. It was also found that oral administration of fucoidan increased the population of natural killer cells in the spleen. Furthermore, from the results of the experiment using Myd-88 knockout mice, it was found that these effects are related to gut immunity. These results suggest that fucoidan is a candidate anti-tumor functional food.     

水稻强化栽培不同插种密度对E52产量的影响初探

为完善水稻强化栽培配套技术 ,我们开展了强化栽培不同移栽密度试验 ,以探索SRI不同密度对水稻产量的影响。一、试验材料和方法试验设五个处理 :40cm×33cm(处理1)、33cm×27cm(处理2)、33cm×20cm(处理3)、27cm×20cm(处理4)、22cm×20cm(处理5) ,试验小区面积67.2m2,秧龄15天     

稻菜轮作下施氮量对水稻产量及构成因素的影响

研究稻田前作蔬菜条件下,施N量对水稻产量及构成因素的影响。结果表明,在施纯N0～97.5kg/hm2范围内,渝优600在施纯N97.5kg/hm2时能获得高产;施N量高低对Q优6号产量影响不很敏感,在施纯N68.5～97.5kg/hm2范围内,产量均相对较高;渝香203在施纯N68.5kg/hm2时能获得高产。本试验水平下各品种N肥利用率大小顺序为:渝香203Q优6号渝优600,当土壤可利用N成为限制因子时,种植渝香203和Q优6号能获得较高产量;当土壤可利用N充分时,种植渝优600能获得高产。     

叶片外源施加硝普钠对渗透胁迫下花生幼苗生长及根系抗氧化系统的影响

一氧化氮(NO)作为一种生物体内重要的信号分子,参与植物生长发育调控和对生物与非生物环境胁迫的应答反应。本试验选取四种NO响应类型,通过在15%PEG胁迫条件下对叶片施加SNP,研究并分析外源NO供体SNP对不同类型花生生长及抗氧化特性的影响。结果表明:NO处理对低含量高诱导品种沂南四粒糙和高含量高诱导品种花育22的干重促进作用最大。NO处理对不同品种根系抗氧化指标的影响也不尽相同。NO和PEG共同处理后,花育22和沂南四粒糙SOD和CAT活性变化不大,POD活性增加明显,MDA和O2-产生速率大幅度降低。而其余两个品种NO处理不利于维持胁迫下抗氧化酶的高活性。根系NO含量增加能够改变胁迫下CAT活性增加的趋势,同时缓解PEG胁迫对地上部物质积累量的影响。     

净套作条件下钼肥拌种对大豆光合特性及产量的影响

在净作和"玉/豆"套作条件下,研究钼肥拌种对大豆光合特性及产量的影响。结果表明:净作条件下大豆叶片的叶绿素Chl(a+b)含量、单株有效荚数、荚粒数、百粒重及产量均显著低于套作,而Chla/b值、净光合速率和蒸腾速率则高于套作;钼肥拌种提高了大豆叶片Chl(a+b)含量、Chla/b值、净光合速率、气孔导度、胞间CO2浓度、蒸腾速率、有效荚数和产量。在净作条件下,上述指标均以2.0g·kg-1处理最高,其次为1.0g·kg-1,其中2.0g·kg-1处理植株叶片的净光合速率、单株有效荚数及产量分别较对照高36.14%、27.32%和37.25%。套作条件下,上述光合指标均以1.0g·kg-1处理最高,其次为2.0g·kg-1,其中1.0g·kg-1处理植株叶片的净光合速率、单株有效荚数及产量分别较对照高34.46%、68.00%和84.85%。可见,钼肥拌种可提高大豆的光合特性及产量,套作模式中钼肥对大豆产量的贡献大于净作,且套作模式中钼肥的最适拌种浓度低于净作。     

单季稻强化高产栽培方式对稻纵卷叶螟发生的影响

为实现精准施药和农药减量控害目标,笔者于2007～2008年对浙江省天台县单季稻强化与常规两种栽培方式稻纵卷叶螟发生情况进行观察比较。结果表明,强化区与常规区稻纵卷叶螟蛾峰消长基本一致,全年共3个峰次,但蛾量略有差异,四(2)代蛾量强化区较常规区高136%,五(3)代与六(4)代蛾量强化区较常规区低24.8%和8.0%,虫苞与虫量调查,6月中下旬三(1)代强化区较常规区分别高8.3%和100%,四(2)代强化区较常规区分别低38.7%和22.3%,五(3)代强化区较常规区分别低34.6%和34.5%。     

施用不同叶面肥对大豆产量的影响

通过对8种叶面肥一年对比试验，初步看出8种叶面肥都有一定的增产效果，以丰秋101增产较明显，增产8．9％。