枸杞多糖的提取纯化及组成分析

采用水提法从枸杞中提取分离枸杞多糖(LBP)用DEAE纤维素柱色谱和凝胶柱色谱进行分离纯化,采用GPC-LLS法、红外光谱和气相色谱等方法对其组成进行研究。结果表明LBP含有3个级分,LBP的分子质量约为1.497×105,由阿拉伯糖(Ara),鼠李糖(Rha),木糖(Xyl),甘露糖(Man),半乳糖(Gal)和葡萄糖(Glc)6种中性单糖组成。     

枸杞色素及多糖的不同提取次序对其得率及抗氧化活性的影响

为探究先后提取枸杞多糖及枸杞色素时对各自得率的影响。本研究通过分别考察这两种成分在提取过程中的提取溶剂、提取温度、料液比、提取次数及提取时间等因素对枸杞色素和枸杞多糖的得率影响,确定枸杞色素和枸杞多糖在提取次序不同时,两者的最佳提取工艺以及对DPPH·和·OH自由基清除率。结果表明,首先提取枸杞多糖后,枸杞色素的最佳提取工艺为采用正己烷,80℃时,料液比1∶10,提取2次,每次1 h,枸杞色素得率为2.48%,此时枸杞多糖得率为7.45%;而首先提取枸杞色素后,采用了超声辅助提取的方式提取枸杞多糖,发现超声效率为25%,料液比1∶10,提取20 min,枸杞多糖得率为5.23%,此时枸杞色素得率为3.93%。因此,首先提取枸杞多糖,使其平均得率为7.45%,而后提取枸杞色素,其平均得率为2.48%;总体上,枸杞色素1和枸杞多糖1对DPPH·自由基清除率都较高,枸杞多糖1对·OH自由基清除率较高,其抗氧化活性都接近Vc。     

枸杞多糖的抗炎镇痛作用研究

为研究枸杞多糖的抗炎镇痛效应及其潜在分子机制,采用小鼠热板实验、小鼠福尔马林炎症疼痛模型和原代培养的背根神经节神经元细胞对疼痛指标和炎症相关分子进行了检测。实验结果显示枸杞多糖能显著缓解后足注射福尔马林引起的动物II相痛表现(P <0. 05),减少动物两后足重量差值(P <0. 001)和血液(P <0. 001)、脊髓(P <0. 05)组织中白细胞介素6的含量,而对小鼠热板潜伏期无明显影响;枸杞多糖降低原代培养的DRG细胞膜上TRPV1介导的钙信号(P <0. 05)。结果证明枸杞多糖具有良好的抗炎镇痛作用,其镇痛机制可能与降低炎症因子白细胞介素6表达及其引起的TRPV1活性增加有关。     

枸杞多糖对H5N1流感全病毒灭活疫苗的体液免疫增强作用

探讨枸杞多糖(Lycium barbarum polysaccharide,LBP)作为佐剂对H5亚型流感病毒全病毒灭活疫苗的体液免疫增强效果。将流感病毒A/Vietnam/1194/2004(H5N1)灭活疫苗与不同剂量的枸杞多糖混合后以腹腔注射的方式共同免疫小鼠,免疫后三周收集血清用于特异性抗体检测。实验中设立氢氧化铝佐剂组作对照共同评价LBP作为佐剂的免疫增强效果。结果显示,小鼠血清中针对H5灭活疫苗的特异性抗体水平在一定范围内随着LBP剂量的增加而提高。LBP在800μg剂量时血清特异性抗体水平较无佐剂组显著增强,并与氢氧化铝佐剂组大致相当。因而,LBP有可能成为一种有效的流感灭活疫苗免疫佐剂。     

Lycium barbarum polysaccharides: Protective effects against heat-induced damage of rat testes and H2O2-induced DNA damage in mouse testicular cells and beneficial effect on sexual behavior and reproductive function of hemicastrated rats

Lycium barbarum, a famous Chinese medicinal herb, has a long history of use as a traditional remedy for male infertility. Polysaccharides are the most important functional constituent in L. barbarum fruits. We systematically investigated the effect of L. barbarum polysaccharides (LBP) on rat testis damage induced by a physical factor (43 degrees C heat exposure), on DNA damage of mouse testicular cells induced by a chemical factor (H2O2), and on sexual behavior and reproductive function of hemicastrated male rats. The results showed that LBP provided a protective effect against the testicular tissue damage induced by heat exposure. When compared with negative control, a suitable concentration of LBP significantly increased testis and epididymis weights, improved superoxide dismutase (SOD) activity, and raised sexual hormone levels in the damaged rat testes. LBP had a dose-dependent protective effect against DNA oxidative damage of mouse testicular cells induced by H2O2. LBP improved the copulatory performance and reproductive function of hemicastrated male rats, such as shortened penis erection latency and mount latency, regulated secretion of sexual hormones and increased hormone levels, raised accessory sexual organ weights, and improved sperm quantity and quality. The present findings support the folk reputation of L. barbarum fruits as an aphrodisiac and fertility-facilitating agent, and provide scientific evidence for a basis for the extensive use of L. barbarum fruits as a traditional remedy for male infertility in China.     

Protective effect of Lycium barbarum polysaccharides on oxidative damage in skeletal muscle of exhaustive exercise rats

The aim of this study was to determine the modulatory effect of Lycium barbarum polysaccharides (LBP) on the oxidative stress induced by an exhaustive exercise. 32 male Wistar rats were taken in the study. The experiment was a 30-day exhaustive exercise program. We determined the lipid peroxidation, glycogen levels, and anti-oxidant enzyme activities in skeletal muscle. The results demonstrated that L. barbarum polysaccharides administration significantly increases glycogen level and anti-oxidant enzyme activities, and decreased malondialdehyde (MDA) level and creatine kinase activities. In conclusion, L. barbarum polysaccharides administration can significantly decrease the oxidative stress induced by the exhaustive exercise.     

Polysaccharides from wolfberry prevents corticosterone-induced inhibition of sexual behavior and increases neurogenesis

Lycium barbarum, commonly known as wolfberry, has been used as a traditional Chinese medicine for the treatment of infertility and sexual dysfunction. However, there is still a scarcity of experimental evidence to support the pro-sexual effect of wolfberry. The aim of this study is to determine the effect of Lycium barbarum polysaccharides (LBP) on male sexual behavior of rats. Here we report that oral feeding of LBP for 21 days significantly improved the male copulatory performance including increase of copulatory efficiency, increase of ejaculation frequency and shortening of ejaculation latency. Furthermore, sexual inhibition caused by chronic corticosterone was prevented by LBP. Simultaneously, corticosterone suppressed neurogenesis in subventricular zone and hippocampus in adult rats, which could be reversed by LBP. The neurogenic effect of LBP was also shown in vitro. Significant correlation was found between neurogenesis and sexual performance, suggesting that the newborn neurons are associated with reproductive successfulness. Blocking neurogenesis in male rats abolished the pro-sexual effect of LBP. Taken together, these results demonstrate the pro-sexual effect of LBP on normal and sexually-inhibited rats, and LBP may modulate sexual behavior by regulating neurogenesis.     

Effect of lycium barbarum polysaccharide on human hepatoma QGY7703 cells: inhibition of proliferation and induction of apoptosis

Lycium barbarum polysaccharide (LBP), extracted from Lycium barbarum that is a kind of traditional Chinese herb, is found to have anticancer activity. In this study, the effect of LBP on the proliferation rate, cell cycle distribution and apoptosis in the human hepatoma QGY7703 cell line were investigated. The effects of this compound were also tested on the concentration of calcium in cells. LBP treatment caused inhibition of QGY7703 cell growth with cycle arrest in S phase and apoptosis induction. The amount of RNA in cells and the concentration of intracellular Ca2+ were increased. Moreover, the distribution of calcium in cells was changed. Taken together, the study suggests that the induction of cell cycle arrest and the increase of intracellular calcium in apoptotic system may participate in the antiproliferative activity of LBP in QGY7703 cells.     

微波-纤维素酶法提取枸杞多糖的工艺研究

枸杞为常用的中药材,其多糖含量高。枸杞多糖在保健、医疗方面应用广泛,目前已有不少枸杞多糖提取方法的研究,但尚无微波-纤维素酶法提取枸杞多糖的研究。为了更好地提取枸杞多糖,满足日益增长的需求,进行了相关研究。最佳工艺条件为：微波功率450 W,微波处理时间6 min,物料为80目,液料比25∶1（mL/g）,纤维素酶用量1.5%,酶解温度50℃,酶解时间60 min,酶解体系pH值4.8,在此工艺条件下,枸杞多糖得率为13.2%。     

Physical characteristics and antioxidant effect of polysaccharides extracted by boiling water and enzymolysis from Grifola frondosa

Grifola frondosa has been widely consumed in China and other Asian countries. Recent studies on G. frondosa have focused on the activities of polysaccharides extracted by water, and the activities of polysaccharides extracted by enzymolysis have not been studied. In this work, the relationship between the physical properties and antioxidant activity of polysaccharides extracted from G. frondosa by boiling water and enzymolysis was studied. Five polysaccharide extracts from the fruit body of G. frondosa were prepared by different extracting methods including boiling water, single enzyme enzymolysis with three different single enzymes (cellulose, pectinase, and pancreatin), and combined enzyme enzymolysis (cellulose:pectinase:pancreatin; 2:2:1). Characteristics such as the viscosity, Mw, polysaccharide content, protein content, infrared spectra, and antioxidant activities of the extracts were evaluated. The highest antioxidant activity was exhibited by the extracts prepared by combined enzyme extraction. The correlation analysis between antioxidant activity and polysaccharide content, protein content, Mw or viscosity indicated that the Mw had a more important role in antioxidant activity. Overall, the results indicate that the combined enzyme polysaccharide extracts can be developed as a new potential natural antioxidant.     

Antioxidative activity of polysaccharide fractions isolated from Lycium barbarum Linnaeus

Antioxidant activity of polysaccharide fractions isolated from Lycium barbarum Linnaeus was evaluated. Polysaccharides were extracted with boiling water, followed by precipitating with ethanol, protein hydrolysis, dialysis, and fractionation with a DEAE–Sepharose CL-6B column. A total of 4 fractions, including 1 neutral polysaccharide (LBPN) and 3 acidic polysaccharides were obtained, and compared with crude polysaccharide (CP), crude extract of polysaccharide (CE), deproteinated polysaccharide (DP), and deproteinated and dialyzed polysaccharide (DDP) for antioxidative activity. With the exception of CE and DDP, most polysaccharides were effective in scavenging DPPH and ABTS⁺ free radicals, superoxide anion and hydroxyl radical at 1000 μg/mL.     

Polysaccharides from Lycium barbarum leaves: Isolation, characterization and splenocyte proliferation activity

The polysaccharides from the fruits of Lycium barbarum have received considerable attention in previous publication, but the polysaccharides from the leaves were rarely reported. In the present work, four water-soluble polysaccharide fractions: LBP-I, LBP-II, LBP-III and LBP-IV isolated from L. barbarum leaves were purified through DEAE-Sephadex A-25. LBP-II and LBP-IV respectively showed one symmetrical peak on HPGPC with average molecular weight of 9.39×10(4)Da and 4.18×10(5)Da. UV and IR analysis of the two fractions showed the characteristics of acidic polysaccharides combined with polypeptides or proteins. GC analysis showed LBP-IV was mainly composed of rhamnose, arabinose, xylose, glucose and galactose with molar ratio of 1.61:3.82:3.44:7.54:1.00, and the uronic acid content was 47.68% (w/w) determined by sulfuric acid-carbazole method. (1)H and (13)C NMR spectra of LBP-IV also showed the presence of carboxyl carbon and five anomeric carbons, and suggested there may be both α- and β-anomeric configurations in this fraction. Moreover, splenocyte proliferation activity assay showed that LBP-IV significantly enhanced the proliferation of splenocyte stimulated by ConA or LPS, indicating the fraction has the beneficial effect on immunostimulating activity.     

沙棘果皮多糖清除氧自由基的活性研究

沙棘(Hippophae rhamnosides)果皮经80℃恒温水浴提取, 乙醇沉淀得粗多糖。Sevag法去蛋白,经50%和70%乙醇分级, 得3种级分沙棘多糖H1、H2和H3; 以Fenton 反应, 即H2O2/Fe2+/水杨酸为.OH产生和检测体系; 以邻苯三酚/EDTA/Tris-HCl为O2 -. 产生体系, 对沙棘多糖H1、H2和H3进行抗氧自由基活 性研究。结果表明, 沙棘多糖对.OH和O2 -. 有较显著的清除能力。不同级分多糖H1、H2和H3浓度达200mg.mL-1时, 对.OH的清除率分别为44.9%、49.0%和26.4%, 抗O2-. 活性分别为36.9%,15.4%和23.1%。多糖质量浓度增大时,两种自由基清除率增加, 且呈量效关系。     

枸杞多糖与黄芪多糖抑菌活性的研究*

目的:研究黄芪多糖和枸杞多糖的抑菌活性并探讨不同pH值对其抑菌活性的影响。方法:采用滤纸片扩散法,分析不同浓度黄芪多糖和枸杞多糖在不同pH值下对几种常见细茵和霉菌(大肠杆菌、沙门氏菌、金黄色葡萄球菌、黑曲霉、产黄青霉)的抑制效果。结果:对于细菌,枸杞多糖8mg/mL时出现抑菌圈,而黄芪多糖0.02 mg/mL时效果最佳;对于霉菌,随着枸杞多糖浓度的增大,抑菌圈的直径增大,而黄芪多糖0.02 mg/mL时效果最佳;当枸杞多糖和黄芪多糖在pH6的条件下,二者抑菌活性均最强。结论:枸杞多糖和黄芪多糖对细菌、霉菌都有一定的抑制效果,pH值可影响枸杞多糖和黄芪多糖的抑菌效果。     

Characterization and antioxidant activity of Ginkgo biloba exocarp polysaccharides

Ginkgo biloba exocarp polysaccharide (GBEP) was obtained by hot water extraction, the crude polysaccharide was deproteinized by Sevag method and fractionized by a DEAE Sepharose fast flow anion-exchange column. Five fragments were obtained, including neutral polysaccharide (GBEP-N) and four acidic polysaccharides (GBEP-A1, GBEP-A2, GBEP-A3 and GBEP-A4). GBEP-N and GBEP-A3 were further purified by Superdex 200 gel column chromatography. The resulted two fractions GBEP-NN, and GBEP-AA were characterized by FT-IR, and HPGFC (high pressure gel filtration chromatography). Monosaccharide composition was determined by RP-HPLC method of precolumn derivatization with 1-phenyl-3-5-pyrazolone. GBEP-NN was mainly composed of rhamnose, arabinose, mannose, glucose and galactose, while GBEP-AA was mainly made up of mannose, rhamnose, glucuronic acid, galacturonic acid, galactosamine, glucose, galactose, xylose, arabinose, and fucose. The crude GBEP exhibited certain antioxidant activity. At the concentration of 5 mg/mL, the hydroxyl radical scavenging effect of GBEP was 90.52%, greater than 77.37% for the positive control ascorbic acid.     

In vitro antioxidant activities of sulfated polysaccharide fractions extracted from Corallina officinalis

Sulfated polysaccharides (F1, F2) from seaweed Corallina officinalis were isolated through anion-exchange column chromatography. Their chemical characteristics were determined by GC, HPLC, FT-IR and UV spectra. F1 and F2 contained only two monosaccharides, namely galactose and xylose. The antioxidant activities of F1, F2 and the de-sulfated polysaccharides (DF-1, DF-2) in vitro were investigated, including hydroxyl radicals scavenging effect, superoxide radical scavenging capacity, DPPH radical activity and reducing power. As expected, antioxidant assay showed that the two sulfated polysaccharide fractions (F1, F2) possessed considerable antioxidant properties and had more excellent abilities than de-sulfated polysaccharides (DF-1, DF-2).     

Activation of the Nrf2/HO-1 Antioxidant Pathway Contributes to the Protective Effects of Lycium Barbarum Polysaccharides in the Rodent Retina after Ischemia-Reperfusion-Induced Damage

Lycium barbarum polysaccharides (LBP), extracts from the wolfberries, are protective to retina after ischemia-reperfusion (I/R). The antioxidant response element (ARE)–mediated antioxidant pathway plays an important role in maintaining the redox status of the retina. Heme oxygenase-1 (HO-1), combined with potent AREs in its promoter, is a highly effective therapeutic target for the protection against neurodegenerative diseases, including I/R-induced retinal damage. The aim of our present study was to investigate whether the protective effect of LBP after I/R damage was mediated via activation of the Nrf2/HO-1-antioxidant pathway in the retina. Retinal I/R was induced by an increase in intraocular pressure to 130 mm Hg for 60 minutes. Prior to the induction of ischemia, rats were orally treated with either vehicle (PBS) or LBP (1 mg/kg) once a day for 1 week. For specific experiments, zinc protoporphyrin (ZnPP, 20 mg/kg), an HO-1 inhibitor, was intraperitoneally administered at 24 h prior to ischemia. The protective effects of LBP were evaluated by quantifying ganglion cell and amacrine cell survival, and by measuring cell apoptosis in the retinal layers. In addition, HO-1 expression was examined using Western blotting and immunofluorescence analyses. Cytosolic and nuclear Nrf2 was measured using immunofluorescent staining. LBP treatment significantly increased Nrf2 nuclear accumulation and HO-1 expression in the retina after I/R injury. Increased apoptosis and a decrease in the number of viable cells were observed in the ganglion cell layer (GCL) and inner nuclear layer (INL) in the I/R retina, which were reversed by LBP treatment. The HO-1 inhibitor, ZnPP, diminished the LBP treatment-induced protective effects in the retina after I/R. Taken together, these results suggested that LBP partially exerted its beneficial neuroprotective effects via the activation of Nrf2 and an increase in HO-1 protein expression.     

Lycium barbarum polysaccharide protects against LPS-induced ARDS by inhibiting apoptosis,oxidative stress,and inflammation in pulmonary endothelial cells

Acute respiratory distress syndrome (ARDS) is a heterogenous syndrome characterised by diffuse alveolar damage, with an increase in lung endothelial and epithelial permeability. Lycium barbarum polysaccharide (LBP), the most biologically active fraction of wolfberry, possesses antiapoptotic and antioxidative effects in distinct situations. In the present study, the protective effects and potential molecular mechanisms of LBP against lipopolysaccharide (LPS)-induced ARDS were investigated in the mice and in the human pulmonary microvascular endothelial cells (HPMECs). The data indicated that pretreatment with LBP significantly attenuated LPS-induced lung inflammation and pulmonary oedema in vivo. LBP significantly reversed LPS-induced decrease in cell viability, increase in apoptosis and oxidative stress via inhibiting caspase-3 activation and intracellular reactive oxygen species (ROS) production in vitro. Moreover, the scratch assay verified that LBP restored the dysfunction of endothelial cells (ECs) migration induced by LPS stimulation. Furthermore, LBP also significantly suppressed LPS-induced NF-κB activation, and subsequently reversed the release of cytochrome c. These results showed the antiapoptosis and antioxidant LBP could partially protect against LPS-induced ARDS through promoting the ECs survival and scavenging ROS via inhibition of NF-κB signalling pathway. Thus, LBP could be potentially used for ARDS against pulmonary inflammation and pulmonary oedema.     

Purification, structure and immunobiological activity of an arabinan-rich pectic polysaccharide from the cell walls of Prunus dulcis seeds

The structure and bioactivity of a polysaccharide extracted and purified from a 4M KOH + H3BO3 solution from Prunus dulcis seed cell wall material was studied. Anion-exchange chromatography of the crude extract yielded two sugar-rich fractions: one neutral (A), the other acidic (E). These fractions contain a very similar monosaccharide composition: 5:2:1 for arabinose, uronic acids and xylose, respectively, rhamnose and galactose being present in smaller amounts. As estimated by size-exclusion chromatography, the acidic fraction had an apparent molecular mass of 762 kDa. Methylation analysis (from the crude and fractions A and E), suggests that the polysaccharide is an arabinan-rich pectin. In all cases, the polysaccharides bear the same type of structural Ara moieties with highly branched arabinan-rich pectic polysaccharides. The average relative proportions of the arabinosyl linkages is 3:2:1:1 for T-Araf:(1-->5)-Araf:(1-->3,5)-Araf:(1-->2,3,5)-Araf. The crude polysaccharide extract and fractions A and E induced a murine lymphocyte stimulatory effect, as evaluated by the in vitro and in vivo expression of lymphocyte activation markers and spleen mononuclear cells culture proliferation. The lymphocyte stimulatory effect was stronger on B- than on T-cells. No evidence of cytotoxic effects induced by the polysaccharide fractions was found.     

Hypolipidemic Activity and Mechanism of Action of Sargassum fusiforme Polysaccharides

Sargassum fusiforme polysaccharide (SFP) is a kind of biologically active macromolecule with biological functions. In this study, oxidative stress and high-fat HepG2 cell models were established to investigate its lipid-lowering activity and mechanism of action. It was found that SFP and its two isolated fractions had antioxidant effects on the cells. It was also found the polysaccharides decreased the content of total cholesterol and total triglyceride in the high-fat cells. RT-qPCR assays revealed that the three polysaccharides down-regulated the mRNA expression level of ACC, PPARγ, and SREBP-2. It could be concluded that the hypolipidemic effect of SFPs is achieved via multiple pathways, including the regulation on the expression level of lipid metabolism-related key enzymes and factors, and binding with bile acids. The hypolipidemic effect of SFPs could be partially due to their antioxidant activity. SFPs developed in the present work have potential as ingredients of functional foods with hypolipidemic effect.