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In the present study, we studied anti-Alzheimer′s disease (AD) activities of chondroitin sulfate (CS) oligosaccharides with different molecular weights. CS from shark cartilage was degraded by a recombinant CS endolyase, chondroitinase ABC I (CHSase ABC I), and CS disaccharide (DP2), tetrasaccharide (DP4), hexasaccharide (DP6), octasaccharide (DP8), decasaccharide (DP10) and dodecasaccharide (DP12) were obtained by separation with gel filtration. Anti-AD activities of CS oligosaccharides were assessed using Aβ-injured SH-SY5Y cells and BV2 cells. It was shown that CS oligosaccharides could block Aβ-induced oxidative stress, mitochondrial dysfunction and activation of intrinsic apoptotic pathway for SH-SY5Y cells. Furthermore, these activities increased with the increase of molecular weights. For Aβ-injured BV2 cells, CS oligosaccharides inhibited oxidative stress, the production of proinflammatory cytokines and the activation of toll-like receptor pathway, and CS DP2 had the best activity among them. In conclusion, CS oligosaccharides suppressed Aβ-induced oxidative stress and relevant injury in vitro, and these effects had different relationships with the molecular weights of CS oligosaccharides for different cell lines, which might be caused by different mechanisms. [ABSTRACT FROM AUTHOR]

Sepiella maindroni ink polysaccharide (SIP) from the ink of cuttlefish Sepiella maindroni and its sulfated derivative (SIP-SII) have been demonstrated to possess diverse biological activities. But little is known about low molecular weight squid ink polysaccharides (LMWSIPs). In this study, LMWSIPs were prepared by acidolysis, and the fragments with molecular weight (M w) distribution in the ranges of 7 kDa to 9 kDa, 5 kDa to 7 kDa and 3 kDa to 5 kDa were grouped and named as LMWSIP-1, LMWSIP-2 and LMWSIP-3, respectively. The structural features of LMWSIPs were elucidated, and their anti-tumor, antioxidant and immunomodulatory activities were also studied. The results showed that with the exception of LMWSIP-3, the main structures of LMWSIP-1 and LMWSIP-2 did not change compared with SIP. Though there were no significant differences in the antioxidant capacity between LMWSIPs and SIP, the anti-tumor and immunomodulatory activities of SIP were enhanced to a certain extent after degradation. It is particularly noteworthy that the activities of LMWSIP-2 in anti-proliferation, promoting apoptosis and inhibiting migration of tumor cells as well as promoting the proliferation of spleen lymphocytes were significantly higher than those of SIP and the other degradation products, which is promising in the anti-tumor pharmaceutical field. • Sepiella maindroni ink polysaccharide (SIP) was degraded by acidolysis to prepare low molecular weight SIPs (LMWSIPs). • The main structures of LMWSIP-1 and LMWSIP-2, except for LMWSIP-3, were not changed compared with SIP. • Compared with SIP and other derivatives, LMWSIP-2 showed the strongest anti-tumor and immunomodulatory activities. • The antioxidant activity of SIP was not altered after degradation. [ABSTRACT FROM AUTHOR]

We have previously reported the application of low molecular weight XG(LM-XG), with molecular weights ranging from 1 × 10 6 Da to 1.5 × 10 6 Da for treating osteoarthritis. In this study, we investigated the anti-apoptotic activity of LM-XG under oxidative stress conditions, activated by hydrogen peroxide (H 2 O 2 )-treated chondrocytes in vitro . Chondrocytes were pretreated with various doses of LM-XG (0, 10, 100, 500, or 1000 μg/mL) or 1000 μg/mL sodium hyaluronate for 12 h, and then exposed to 0.5 mmol/L H 2 O 2 for another 12 h. After treatment, chondrocyte viability was evaluated using a cell counting kit-8; DNA fragmentation was detected using Hoechst33258 staining; the percentage of DNA fragmentation was evaluated using the diphenylamine DNA assay kit; the apoptosis rate was evaluated using flow cytometry; chondrocyte ultra-microscopic morphology was observed using transmission electron microscopy; intracellular reactive oxygen species levels were observed and quantified using 2,7-dichlorofuorescin diacetate, mitochondrial permeability transition analysis was performed using MitoTracker Red CMXRos and 4′,6-diamidino-2-phenylindole staining; and finally, caspase-3 activity was detected by western blot. The results showed that, compared with H 2 O 2 -treated chondrocytes, LM-XG improved cell viability, decreased the percentage of DNA fragmentation, reduced the apoptosis rate, decreased the levels of intracellular reactive oxygen species and mitochondrial permeability transition, reverted the morphological damage, and downregulated cleaved caspase-3 levels. These results demonstrate that LM-XG has anti-apoptotic activity in H 2 O 2 -treated chondrocytes. [ABSTRACT FROM AUTHOR]

Osteoarthritis (OA) is one of the most common chronic diseases and characterized by degradation of articular cartilage. We have previously reported xanthan gum (XG) injection preparation with high molecular weights ( Mw ) in ranging from 3 × 10 6 Da to 5 × 10 6 Da (HM-XG) could enhance the viscosity of synovial fluid, protect joint cartilage in rabbit, and the therapeutical effect has no significance difference with an existing clinical medication (sodium hyaluronate, SH) at the same injection frequency (once weekly for 5 weeks). Herein, we prepared a XG injection preparation with a low M w (LM-XG) in ranging from 1 × 10 6 Da to 1.5 × 10 6 Da, and evaluated the therapeutical effect for OA therapy at once every 2 weeks for 5 weeks with an SH at once weekly for 5 weeks as reference. The model of OA was induced using anterior cruciate ligament transection (ACLT) in a rabbit in vivo and also using sodium nitroprusside (SNP) in cell culture in vitro . The results showed that LW-XG could also protect cartilage from damage, decrease the concentration of nitric oxide (NO) in synovial fluid and reverse the amplification of the knee joint width similar to HM-XG as our previously reported. At the cellular level, LW-XG promotes proliferation while decreases apoptosis of chondrocytes. Mechanistically at the molecular level, these effects are elicited via down-regulation of the protein levels of caspase-3 and bax and up-regulation of the protein levels of bcl-2 in cartilage in both in vivo and in vitro. These results showed that LW-XG maybe become an excellent candidate long-acting drug for treating OA. [ABSTRACT FROM AUTHOR]

A practical molecular weight determination model of xanthan gum (XG), based on near-infrared (NIR) spectroscopy, was built in this study. Two sample measurement modules, integrating sphere module and fiber-optic probe module, were compared, and the best partial least square (PLS) regression model was based on fiber-optic probe module. The values of coefficient of determination in calibration ( R 2 c ), coefficient of determination in prediction ( R 2 p ), residual predictive deviation (RPD) and root mean square error of prediction (RMSEP) were 0.967, 0.975, 6.028 and 0.250 × 10 6 Da, respectively. The molecular weight range, linearity, accuracy and precision of the established method were also validated. Furthermore, influence factors on this method were discussed in order to establish an appropriate measurement protocol. Results showed that the proposed NIR method may be suitable for practical applications in manufacturing plants and probably be accepted as a good alternative approach for fast determination of molecular weight of XG in production process. [ABSTRACT FROM AUTHOR]

Abstract: The purpose of this report was to demonstrate the effect of amphiphilic polysaccharides-based self-assembling micelles on enhancing the oral absorption of low molecular weight chondroitin sulfate (LMCS) in vitro and in vivo, and identify the transepithelial transport mechanism of LMCS micelles across the intestinal barrier. α-Linolenic acid-low molecular weight chondroitin sulfate polymers(α-LNA–LMCS) were successfully synthesized, and characterized by FTIR, 1HNMR, TGA/DSC, TEM, laser light scattering and zeta potential. The significant oral absorption enhancement and elimination half-life (t 1/2) extension of LNA–LMCS2 in rats were evidenced by intragastric administration in comparison with CS and LMCS. Caco-2 transport studies demonstrated that the apparent permeability coefficient (P app) of LNA–LMCS2 was significantly higher than that of CS and LMCS (p <0.001), and no significant effects on the overall integrity of the monolayer were observed during the transport process. In addition, α-LNA–LMCS micelles accumulated around the cell membrane and intercellular space observed by confocal laser scanning microscope (CLSM). Furthermore, evident alterations in the F-actin cytoskeleton were detected by CLSM observation following the treatment of the cell monolayers with α-LNA–LMCS micelles, which further certified the capacity of α-LNA–LMCS micelles to open the intercellular tight junctions rather than disrupt the overall integrity of the monolayer. Therefore, LNA–LMCS2 with low cytotoxicity and high bioavailability might be a promising substitute for CS in clinical use, such as treating osteoarthritis, atherosclerosis, etc. [Copyright &y& Elsevier]

Highlights: [•] Curdlan sulfates with different molecular weights and sulfur contents were synthesized by modification of curdlan with sulfur trioxide–pyridine complex. [•] Curdlan sulfate shows significant activity on macrophages activation and BMDCs maturation. [•] The higher molecular weight and higher sulfur content stereometrically interfere with the binding affinity of curdlan sulfate with the receptor dectin-1. [ABSTRACT FROM AUTHOR]

Abstract: Endostatin (ES), a potent endogenous angiogenesis inhibitor found in 1997 by O’Reilly, can effectively inhibit angiogenesis, inhibit the growth and metastasis of tumors. ES can also decrease drug resistance in long term and repeated treatment when it is used in combination with other chemotherapeutic agents. But there are still lots of obstacles on its clinical application, such as the need of a high dose to maintain its efficacy short half-life, poor stability, expensive, and some other shortcomings just like other protein drugs. Chemical modification on ES by polyethylene glycol (PEG) and low molecular weight heparin (LMWH) were successfully carried out in order to obtain a better ES derivative. Several classic experimental models were employed to study the bioactivity of ES and modified ES, including chicken chorioallantoic membrane (CAM) assay, corneal neovascularization (CNV) assay and Sarcoma 180 tumor bearing mice assay. The results showed that PEG-ES and LMWH-ES had better anti-angiogenesis and anti-tumor activity than ES, which indicates that LMWH was also a good protein modifier. [Copyright &y& Elsevier]

Abstract: Aims: Oligosaccharides of hyaluronan (o-HAs) were proved to have pro-angiogenic activities. The aim of this study was to obtain four hyaluronan oligosaccharides (o-HAs) of defined molecular weight including 4 saccharide residues (o-HA4), 6 saccharide residues (o-HA6), 8 saccharide residues (o-HA8), and 10 saccharide residues (o-HA10) under optimum conditions, and compare their angiogenic activities. Main methods: The four o-HAs were prepared by digesting the native high molecular weight HA with hyaluronidase under optimum conditions. The effects of the four o-HAs on human umbilical vein endothelial cell (HUVEC) proliferation were measured using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenil tetrazolium bromide (MTT) assay. Angiogenic effects of the four o-HAs were evaluated using chicken chorioallantoic membrane (CAM) assay. The effects of the four o-HAs on the vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) messenger ribonucleic acid (mRNA) expressions were detected by semi-quantitative polymerase chain reaction (PCR). Key findings: O-HA6, o-HA8 and o-HA10 could effectively promote the proliferation of HUVEC, induce angiogenesis in the CAM assay and increase VEGF mRNA levels in HUVEC. No significant effects were found with o-HA4. Significance: These results suggested that o-HA6, o-HA8, and o-HA10, but not o-HA4 were effective angiogenic factors. [Copyright &y& Elsevier]

Abstract: Low-molecular-weight heparin (LMWH) and Cu,Zn-superoxide dismutase (SOD) were extensively investigated on preventing brain reperfusion injury after ischemia (BRII) in the past few years and both exhibited some advantages as well as limits in practice. To explore whether chemical modification for LMWH and SOD can lead to improved bioactivity, in our present study, we examined the efficacy of LMWH conjugated SOD (LMWH−SOD) in the model of BRII gerbils. Ischemia/reperfusion was performed for 5 min by clamping the bilateral common carotid arteries of gerbils. LMWH−SOD, SOD and the mixture of LMWH and SOD (LMWH+SOD) were administered intravenously to corresponding animals just before ischemia. 24 h after reperfusion, serum malondialdehyde (MDA) content and SOD activity were measured, the expression of intercellular adhesion molecule-1 (ICAM-1) was examined by immunohistochemistry, and the brain sections were processed for Nissl staining and terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end-labeling. The results showed that LMWH−SOD significantly lowered MDA content (P <0.001, versus SOD and LMWH+SOD) and elevated SOD activity (P <0.05, versus SOD and LMWH+SOD) in the serum of BRII gerbils. Immunohistochemical results indicated ICAM-1 positive staining was lighter, pyramidal cells of hippocampal CA1 region were more regular and the changes in cell edema were minor, and apoptosis of hippocampal cells was milder in LMWH−SOD treated animals than in SOD or LMWH+SOD treated animals, untreated BRII animals and sham-operated animals. The results suggest that the novel LMWH−SOD conjugate can inhibit upregulation of ICAM-1 and prevent neuronal cell apoptosis in BRII gerbils, and the LMWH−SOD conjugate has better anti-inflammatory and neuroprotective effects in BRII than native SOD and the mixture of LMWH and SOD. [Copyright &y& Elsevier]

Our previous study found that low molecular weight chondroitin sulfate (LMWCS) had neuroprotective effects against the toxicity of amyloid-β (Aβ) peptides both in vitro and in vivo , and we speculated that the effects might be related with its anti-oxidative activities. In this study, the anti-Alzheimer′s disease (AD) activity of LMWCS was further studied in 5XFAD transgenic mice. After 4-month gavage, the levels of Aβ 1-42 level, amyloid precursor protein (APP) and presenilin 1 (PS1) were significantly decreased in the brains of 5XFAD mice, indicating the alteration of APP metabolism by LMWCS. Besides, LMWCS inhibited the secretions of pro-inflammatory cytokines, including interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) and IL-6. Furthermore, the suppression of neuroinflammation by LMWCS was supported by the decreased expressions of glial fibrillary acidic protein (GFAP) and toll-like receptor 2 (TLR2) in the brains. LMWCS also reduced the production of reactive oxygen species (ROS) and the level of phospho-tau (Ser404) in the brains. Nevertheless, the changes in the behavior tests were moderate. In conclusion, LMWCS administration ameliorated APP metabolism, neuroinflammation, ROS production and tau protein abnormality in the brains of 5XFAD mice, displaying the potential to improve the pathological changes of AD mouse brain. LMWCS could be considered as a promising anti-AD drug candidate, nonetheless, the therapy regimen need to be optimized to improve its pharmacotherapy efficacy. • The anti-Alzheimer′s disease function of low molecular weight chondroitin sulfate (LMWCS) was studied using a transgenic mouse model, 5XFAD. • The production of Aβ in the brain was significantly decreased via the suppression of amyloid precursor protein and presenillin 1 • The productions of pro-inflammatory cytokines, the activation of glial cells and inflammatory pathways in the brain were inhibited. • The oxidative stress was inhibited. [ABSTRACT FROM AUTHOR]

Abstract: A new heteropolysaccharide, named as SIP, was isolated from the ink of cuttlefish, Sepiella maindroni, by enzymolysis, anion-exchange and gel-permeation chromatography and tested for its antimutagenic activity. It was homogeneous with a molecular weight of 1.13×104 Da by HPSEC–MALLS analysis. SIP contained glucuronic acid, mannose, N-acetylgalactosamine, and fucose in a molar ratio of 1:1:2:2. Its structural characteristics were investigated and elucidated by methylation analysis, GLC–MS, and NMR (1H, 13C, H–H COSY, HMQC, HMBC, TOCSY and NOESY). The hexasaccharide repeating unit of SIP was found to be a backbone composed of fucose, N-acetylgalactosamine and mannose in a molar ratio of 2:2:1, and with a single branch of glucuronic acid at the C-3 position of mannose. According to the micronucleus test, SIP could significantly reduce the frequency of micronucleated cells in polychromatic erythrocytes and reticulocytes induced by cyclophosphamide in tumor-bearing mice, which revealed that SIP presented strong antimutagenic activity. [Copyright &y& Elsevier]