Sitagliptin and fucoidan prevent apoptosis and reducing ER stress in diabetic rat testes

Sitagliptin increases the levels of incretin hormones and stimulates a decrease in blood glucose levels, by blocking the DPP4 enzyme. We have very limited information about impact of sitagliptin on male genital system and relationship between sitagliptin/diabetes/ER. Fucoidan can be effective in blood glucose homeostasis. We goal to explain of the effect of sitagliptin and introduce an approach of fucoidan treatment in experimental diabetes in male rats. Fifty-eight Wistar albino rats were divided into C-control group and D-diabetes group: 60 mg/kg streptozotocin intraperitoneal (i.p.); DS group: STZ + 10 mg/kg sitagliptin intragastric (i.g.); DF group: STZ + 100 mg/kg fucoidan i.p.; and DSF group: STZ + 10 mg/kg sitagliptin + 100 mg/kg fucoidan. A significant decrease was detected when DS, DF and DSF groups compared to group D in blood glucose levels, basement membrane thickness and also apoptotic cell/tubule index, pJNK, caspase 3, caspase 12, GRP78, CHOP and DPP4. Sitagliptin and fucoidan have been found to be effective in blood glucose homeostasis and reducing the expression of certain proteins that lead to apoptosis and especially the proteins in the ER stress pathway. Therefore, we think that both sitagliptin and fucoidan can be effective in preventing or eliminating histopathological damages in diabetic testicular tissues, and their treatment effects can be used more.     

褐藻糖胶促进小鼠巨噬细胞免疫活性及机制初探

目的 探讨褐藻糖胶(Fucoidan)对小鼠巨噬细胞RAW264.7免疫活性的影响及初步探讨作用机制。方法 采用体外细胞培养方法,比色分析检测不同浓度Fucoidan(0、100、200、300、400、500 μg/mL)作用下RAW264.7吞噬中性红的能力,噻唑蓝(MTT)法检测不同浓度Fucoidan(0、50、250、500 μg/mL)作用下RAW264.7增殖,Western Blotting检测Fucoidan诱导的RAW264.7的MAPK/ERK1/2的磷酸化。结果 Fucoidan剂量依赖性地促进RAW264.7吞噬功能和增殖功能。200 μg/mL Fucoidan作用10min即使ERK1/2发生磷酸化,30min时ERK1/2磷酸化达到最大值。结论 Fucoidan可提高小鼠巨噬细胞的吞噬活性和增殖能力,其机制可能与Fucoidan直接激活RAW264.7的MAPK/ERK1/2信号转导通路有关。     

海参岩藻聚糖硫酸酯对巨噬细胞的调节作用及信号通路研究

目的研究海参岩藻聚糖硫酸酯(SC-FUC)对巨噬细胞的调节作用及相关信号通路,探究其调节机体免疫的作用机制。方法噻唑蓝(MTT)比色法检测巨噬细胞的增殖情况;中性红法检测吞噬活性;Griess试剂法测定培养上清液中NO含量;RT-PCR检测巨噬细胞下游细胞因子IL-6、IL-10、Toll样受体和相关信号分子My D88、TRIF、NF-κB的mRNA表达量。结果 SC-FUC对巨噬细胞增殖、吞噬能力和NO分泌均有促进作用,在作用前期(6h和12h)效果更为明显。SC-FUC能上调细胞因子IL-6和IL-10的mRNA表达量,上调TLR4、TLR5、TLR9的表达量,促进信号分子My D88、TRIF和NF-κB的mRNA表达量。结论 SC-FUC能够激活巨噬细胞,促进其分泌NO、IL-6、IL-10等细胞因子,从而发挥免疫调节作用。SC-FUC激活巨噬细胞的信号通路与细胞表面TLR4、TLR5、TLR9及NF-κB通路相关。     

Spray-dried fucoidan microparticles for pulmonary delivery of antitubercular drugs

Pulmonary tuberculosis accounts for 80% of cases and the delivery of antitubercular drugs into the lungs allows targeting the infected organ and, possibly, reducing systemic drug toxicity. This work aimed at using fucoidan as matrix of inhalable microparticles that associate two first-line antitubercular drugs, for an application in pulmonary tuberculosis therapy. Fucoidan is composed of fucose and sulphated sugar residues, moieties described as being recognised by surface receptors of alveolar macrophages, which host mycobacteria. Inhalable fucoidan microparticles loaded with antitubercular drugs were successfully produced with high association efficiencies of either isoniazid (95%) or rifabutin (81%). The microparticles evidenced no cytotoxicity on lung epithelial cells (A549). However, rifabutin-loaded microparticles showed a certain degree of toxicity on macrophage-like cells (THP-1) at the highest tested concentration (1?mg/mL). Furthermore, microparticles showed favourable aerodynamic properties for deep lung delivery (MMAD 2.0–3.8?µm) and, thus, show potential for an application as inhalable tuberculosis therapy.     

Exploiting biological activities of brown seaweed Ecklonia cava for potential industrial applications: a review

Seaweeds are rich in vitamins, minerals, dietary fibres, proteins, polysaccharides and various functional polyphenols. Many researchers have focused on brown algae as a potential source of bioactive materials in the past few decades. Ecklonia cava is a brown seaweed that is abundant in the subtidal regions of Jeju Island in the Republic of Korea. This seaweed attracted extensive interest due to its multiple biological activities. E. cava has been identified as a potential producer of wide spectrum of natural substances such as carotenoids, fucoidans and phlorotannins showing different biological activities in vital industrial applications including pharmaceutical, nutraceutical, cosmeceutical and functional food. This review focuses on biological activities of the brown seaweed E. cava based on latest research results, including antioxidant, anticoagulative, antimicrobial, antihuman immunodeficiency virus, anti-inflammatory, immunomodulatory, antimutagenic, antitumour and anticancer effects. The facts summarized here may provide novel insights into the functions of E. cava and its derivatives and potentially enable their use as functional ingredients in potential industrial applications.     

The polysaccharide fucoidan inhibits microvascular thrombus formation independently from P- and L-selectin function in vivo

BACKGROUND: Adhesion molecules of the selectin family (mainly P- and L-selectin) have been suggested to mediate interactions between platelets, leukocytes and endothelial cells in thrombus formation. The polysaccharide fucoidan has anticoagulative properties, but is also able to bind and block the function of the selectins. Here, we investigated in vivo (i) if fucoidan can prevent microvascular thrombus formation, and (ii) whether this is potentially mediated by the inhibition of P-and/or L-selectin. MATERIALS AND METHODS: For this purpose, we used intravital microscopy in the mouse cremaster microcirculation in which thrombosis was induced photochemically by light exposure to individual arterioles and venules after intravenous (i.v.) injection of FITC-dextran. RESULTS: We found that intravenous administration of fucoidan significantly prolonged the time required for complete occlusion in arterioles and venules by almost seven- and nine-fold, respectively. In contrast, treatment with monoclonal antibodies against P- and L-selectin had no effect on the development of microvascular thrombosis. Fucoidan and also the anti-P-selectin antibody completely inhibited baseline venular leukocyte rolling in the cremaster muscle, indicating that these treatment regimes abolished P-selectin function. Importantly, fucoidan and the anti-P-selectin antibody had no effect on systemic platelet and leukocyte counts. On the other hand, we found that fucoidan treatment significantly altered coagulation parameters, including prothrombin time (Quick percentage), activated partial thromboplastin time (APTT) and thrombin clotting time (TCT), which may explain the potent in vivo anticoagulative effect of fucoidan observed here. CONCLUSIONS: Taken together, our novel findings suggest that fucoidan effectively prevents microvascular thrombus formation induced by endothelial damage in arterioles and venules in vivo. This protective effect of fucoidan is not attributable to inhibition of P- and L-selectin function but may instead be related to the anticoagulative capacity of fucoidan.     

岩藻聚糖硫酸酯FV对大鼠的抗血栓作用研究

目的探讨岩藻聚糖硫酸酯FV对大鼠的抗血栓作用。方法将60只Wistar大鼠随机分为对照组、岩藻聚糖硫酸酯FV 20、10、5、2.5 mg/kg组和低分子肝素钙注射液(LMWHC)213 IU/kg组,每组各10只。分别在下腔静脉血栓模型、体外血栓模型和动静脉旁路血栓模型中研究FV的抗血栓作用,比较血栓干湿质量并计算血栓抑制率。结果 FV 20、10、5、2.5mg/kg能够显著降低大鼠下腔静脉血栓、体外形成的血栓、动静脉旁路中血栓的干湿质量,对血栓湿质量的抑制率最高可达97.4%、94.3%、51.2%,对血栓干质量的抑制率最高可达91.8%、96.6%、64.0%,有明显的抑制血栓形成作用。结论 FV能够抑制血栓形成,量效关系好,具有开发为抗血栓药的良好前景。     

Amelioration of experimental autoimmune encephalomyelitis in Lewis rats treated with fucoidan

We examined whether fucoidan affected the clinical symptoms of experimental autoimmune encephalomyelitis (EAE) in rats. EAE was induced in Lewis rats that were immunized with guinea‐pig myelin basic protein (MBP) and complete Freund's adjuvant. Fucoidan (50 mg/kg, daily) was administered to rats with EAE intraperitoneally, either in the EAE induction phase from either 1 day before immunization to day 7 post‐immunization (PI), or the effector phase from day 8 to 14 PI, to test which phase of rat EAE is affected by fucoidan treatment. The onset, severity and duration of EAE paralysis in the fucoidan‐treated group in the days 8–14 PI‐treated rats, but not in days ?1–7 PI‐treated rats, were significantly delayed, suppressed and reduced, respectively, compared with the vehicle‐treated controls. Treatment with fucoidan reduced the encephalitogenic response and TNF‐α production during EAE. Moreover, the clinical amelioration coincided with decreased infiltration of inflammatory cells in the EAE‐affected spinal cord. The ameliorative effect of fucoidan on clinical paralysis in EAE‐affected rats may be mediated, in part, by the suppression of the autoreactive T cell response and inflammatory cytokine production. Copyright © 2009 John Wiley & Sons, Ltd.     

海带中褐藻糖胶的超声提取工艺的优化

目的研究以水为溶剂超声波强化提取海带褐藻糖胶的工艺。方法采用正交设计,以超声提取时间、超声功率、固液比和提取温度为考察因素,优选了超声波提取海带中褐藻糖胶的最佳工艺。结果各因素对提取率的影响大小依次为：超声提取时间〉固液比〉提取温度〉超声功率,优选的最佳提取工艺为：超声作用时间30 min,固液比1∶30,提取温度40℃,超声功率320 W。按此条件重复实验3次,测得褐藻糖胶的提取量为19.89 mg.g-1。结论较之传统提取方法,超声法提取海带中褐藻糖胶具有省时、节能等优点。