-
[show abstract]
[hide abstract]
ABSTRACT: Chitosan oligosaccharides (COS) have been reported to exert many biological activities, such as antioxidant, antitumor and anti-inflammatory effects. In the present study, we examined the effect of COS on nitric oxide (NO) production in LPS induced N9 microglial cells. Pretreatment with COS (50~200 μg/ml) could markedly inhibit NO production by suppressing inducible nitric oxide synthase (iNOS) expression in activated microglial cells. Signal transduction studies showed that COS remarkably inhibited LPS-induced phosphorylation of p38 MAPK and ERK1/2. COS pretreatment could also inhibit the activation of both nuclear factor-κB (NF-κB) and activator protein-1 (AP-1). In conclusion, our results suggest that COS could suppress the production of NO in LPS-induced N9 microglial cells, mediated by p38 MAPK and ERK1/2 pathways.
Glycoconjugate Journal 05/2012; 29(5-6):285-95. · 2.12 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To investigate whether and how COS inhibited IL-8 production in LPS-induced human umbilical vein endothelial cells (HUVECs).
RT-PCR, enzyme-linked immunosorbent assays (ELISA) and Western blotting were used to study IL-8 expression and related signaling pathway. Wound healing migration assays and monocytic cell adhesion analysis were used to explore the chemotactic and adhesive activities of HUVECs.
COS 50-200 μg/mL exerted a significant inhibitory effect on LPS 100 ng/mL-induced IL-8 expression in HUVECs at both the transcriptional and translational levels. In addition, COS 50-200 μg/mL inhibited LPS-induced HUVEC migration and U937 monocyte adhesion to HUVECs in a concentration-dependent manner. Signal transduction studies suggest that COS blocked LPS-induced activation of nuclear factor-κB (NF-κB) and activator protein-1 (AP-1) as well as phosphorylation of p38 mitogen-activated protein kinase (MAPK) and phosphokinase Akt. Further, the over-expression of LPS-induced IL-8 mRNA in HUVECs was suppressed by a p38 MAPK inhibitor (SB203580, 25 μmol/L) or a phosphatidylinositol 3-kinase (PI3K) inhibitor (LY294002, 50 μmol/L).
COS inhibited LPS-induced IL-8 expression in HUVECs through the blockade of the p38 MAPK and PI3K/Akt signaling pathways.
Acta Pharmacologica Sinica 04/2011; 32(4):478-86. · 1.95 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Sepsis and its derivative syndromes are major causes of morbidity and mortality in the intensive care unit. Recently, lots of studies have shown that the progression of sepsis is attributed to redox imbalance and overproduction of proinflammatory cytokines. In previous studies, we have reported the anti-oxidative and anti-inflammatory effects of chitosan oligosaccharides in vitro. In the light of these findings, we applied the model of sepsis to mice by LPS injection to investigate whether chitosan oligosaccharides have a protective effect on LPS-induced sepsis. We found that treatment by chitosan oligosaccharides not only attenuated organ dysfunction but also improved survival rate after LPS injection. To further understand how it works, we examined several proinflammatory markers including neutrophil infiltration in organs and TNF-α and IL-1β in serum, and found that these cytokines were significantly reduced by chitosan oligosaccharide treatment. In addition to this, anti-oxidants including glutathione (GSH) and catalase (CAT) levels were depleted and malondialdehyde (MDA) levels were increased in LPS-induced sepsis, while chitosan oligosaccharides smoothed out the redox imbalance. Furthermore, we also assessed c-Jun NH(2)-terminal kinase and p38 mitogen-activated protein kinase signal activation by LPS-stimulation, and found both of them were attenuated by chitosan oligosaccharide treatment. Collectively, our data demonstrated that chitosan oligosaccharides can protect mice from the LPS challenge by virtue of anti-inflammatory effects as well as anti-oxidation properties, which might offer beneficial effects for patients with sepsis.
International immunopharmacology 11/2010; 11(1):121-7. · 2.21 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The aim of this study was to investigate the inhibitory effect of geniposide on lipopolysaccharide (LPS)-induced interleukin-6 (IL-6) and interleukin-8 (IL-8) production in human umbilical vein endothelial cells (HUVECs).
Primary HUVECs were used. The mRNA/protein levels of IL-6 and IL-8 was determined by reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). LPS-induced HUVEC migration and adhesion of monocytes to HUVECs were studied by monolayer wound healing experiments and monocytic cell adhesion assay, respectively. Expression of nuclear factor kappaB (NF-kappaB), inhibitory factor kappaB-alpha (IkappaB-alpha), p38 mitogen-activated protein kinase (MAPK) and ERK1/2 were determined by Western blot analysis.
Geniposide effectively inhibited LPS-induced expression of IL-6 and IL-8 in HUVECs at the transcription and translation levels. Additionally, geniposide suppressed LPS-induced HUVEC migration and U937 monocyte adhesion to HUVECs. Signal transduction studies indicate that geniposide blocked the activation of NF-kappaB, degradation of IkappaB-alpha, and phosphorylation of p38 MAPK and ERK1/2 in HUVECs challenged by LPS.
The results show that geniposide can inhibit LPS-induced IL-6 and IL-8 production in HUVECs by blocking p38 MAPK and ERK1/2 signaling pathways.
Agents and Actions 06/2010; 59(6):451-61. · 1.59 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To determine the inhibitory effect of tetramethylpyrazine (TMP) on lipopolysaccharide (LPS)-induced over-production of nitric oxide (NO) and inducible nitric oxide synthase (iNOS) in N9 microglial cells.
N9 cells were pretreated with vehicle or TMP and then exposed to LPS for the time indicated. Cell viability was determined by methylthiazoyltetrazolium (MTT) assay. Nitrite assay was performed by Griess reaction. Expression of iNOS mRNA was examined by RT-PCR. Protein levels of iNOS, p38 mitogen-activated protein kinase (MAPK), ERK1/2, JNK, phosphatidylinositol 3-kinase (PI3K) and Akt were determined by western blot analysis. Formation of reactive oxygen species (ROS) was evaluated by fluorescence image system.
TMP inhibited LPS-induced over-production of NO and iNOS in N9 cells. TMP also inhibited the NF-kappaB translocation from cytoplasm into nucleus of N9 cells. In addition, TMP showed blocking effect on the phosphorylation of p38 MAPK, ERK1/2, JNK and Akt, but not PI3K. Further, TMP suppressed the formation of intracellular ROS in LPS-induced N9 cells.
TMP inhibited production of NO and iNOS in LPS-induced N9 cells through blocking MAPK and PI3K/Akt activation and suppressing ROS production.
Journal of ethnopharmacology 04/2010; 129(3):335-43. · 2.32 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Chitosan oligosaccharides (COS) have been reported to exert anti-fungal activities, antitumour activities and immuno-enhancing effects. However, the potential roles of COS in the treatment of vascular inflammations remain unknown. In the present study, we examined the effects of COS on interleukin-6 (IL-6) production in human umbilical vein endothelial cells (HUVECs) induced by lipopolysaccharide (LPS). Induction of HUVECs with LPS (100 ng/ml) increased the mRNA expression and protein secretion of IL-6 (versus the vehicle-treated group, p < 0.01), which were significantly reverted by the pre-treatment with COS (50-200 microg/ml) for 24 hr before LPS exposure (versus the LPS-treated group, p < 0.05 or 0.01). Signal transduction studies showed that the pre-treatment of HUVECs with COS (50-200 microg/ml) for 24 hr markedly inhibited the LPS-induced over-expression of phosphorylated p38 mitogen-activated protein kinase (MAPK), phosphorylated ERK1/2 and nuclear factor kappaB (NF-kappaB). Moreover, the LPS-induced NF-kappaB activation was suppressed by the specific ERK1/2 inhibitor PD98059 (30 microM) (versus the LPS-treated group, p < 0.01), but not by the specific p38 MAPK inhibitor SB203580 (25 microM). Additionally, both MAPK inhibitors markedly suppressed LPS-induced IL-6 mRNA expression in HUVECs (versus the LPS-treated group, p < 0.01). In conclusion, our results suggest that COS inhibit LPS-induced up-regulation of IL-6 in HUVECs, and this can be regulated by at least two parallel signalling pathways: one via p38 MAPK pathway independent of NF-kappaB activation and one via ERK1/2 pathway dependent on NF-kappaB activation.
Basic & Clinical Pharmacology & Toxicology 11/2009; 106(5):362-71. · 2.18 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: In order to study Brassica napus fatty acid (FA) metabolism and relevant regulatory networks, a systematic identification of fatty acid (FA) biosynthesis-related genes was conducted. Following gene identification, gene expression profiles during B. napus seed development and FA metabolism were performed by cDNA chip hybridization (>8000 EST clones from seed). The results showed that FA biosynthesis and regulation, and carbon flux, were conserved between B. napus and Arabidopsis. However, a more critical role of starch metabolism was detected for B. napus seed FA metabolism and storage-component accumulation when compared with Arabidopsis. In addition, a crucial stage for the transition of seed-to-sink tissue was 17-21 d after flowering (DAF), whereas FA biosynthesis-related genes were highly expressed primarily at 21 DAF. Hormone (auxin and jasmonate) signaling is found to be important for FA metabolism. This study helps to reveal the global regulatory network of FA metabolism in developing B. napus seeds.
Molecular plant 09/2009; 2(5):1107-22. · 5.55 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Chitosan oligosaccharides (COS) have been reported to have anticancer activity, immuno-enhancing effect and antimicrobial activity. However, other biological activities are unknown. Herein, we investigated the protective effects of COS against hydrogen peroxide (H(2)O(2))-induced oxidative damage on human umbilical vein endothelial cells (HUVEC, ECV304 cells). After 24h pre-incubation with COS (25-200 microg/ml), the viability loss in ECV304 cells induced by H(2)O(2) (300 microM) for 12h was markedly restored in a concentration-dependent manner as measured by MTT assay. This effect was accompanied by a marked decrease in intracellular reactive oxygen species (ROS) by measuring intensity of DCFH fluorescence. COS also exerted preventive effects on suppressing the production of lipid peroxidation such as malondialdehyde (MDA), restoring activities of endogenous antioxidants including superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), along with the capacity of increasing levels of nitric oxide (NO) and nitric oxide synthase (NOS), as were determined by commercial regent kits. In addition, pre-incubation of COS with ECV304 cells for 24h resulted in the reduction of apoptosis and the induction of cell cycle arrest in G(1)/S+M phase as assayed quantitatively by Annexin V-fluorescein isothiocyanate (FITC) apoptosis detection kit using flow cytometry. Taken together, our findings suggest that COS can effectively protect HUVECs against oxidative stress by H(2)O(2), which might be of importance in the treatment of cardiovascular diseases.
Pharmacological Research 01/2009; 59(3):167-75. · 4.44 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To confirm the inactivating effect of chito-oligosaccharides on Tobacco mosaic virus (TMV) par ticles in vitro, the difference of TMV pathogenicity was evaluated according to the decrease of local lesion numbers after inoculating with TMV mixed with chito-oligosaccharides (DP3-10) in Nicotiana glutinosa, and the virion structural change was studied by transmission electron microscopy after mixed with chito-oligosaccharides. In the range of tested concentrations of chito-oligosaccharides (100-1000 microg /mL), the numbers of local lesions were strongly reduced with over 30% decrement, and the 88.4% reduction gained at the concentration of 600g /mL. It revealed that treatment with chito-oligosaccharide solution of 300-500 microg /mL directly broke TMV particles into tiny pieces of 50-150nm long, and that treatment with solutions of 600-1000 microg/mL caused virus particle agglomerated. The data presented here suggested that chito-oligosaccharides exerted strong inactivating effect on plant virus in vitro.
Bing du xue bao = Chinese journal of virology / [bian ji, Bing du xue bao bian ji wei yuan hui] 02/2008; 24(1):76-8.
-
[show abstract]
[hide abstract]
ABSTRACT: In order to reveal the antithrombotic mechanism of propylene glycol mannite sulfate (PGMS) on gene level and explore the correlation between PGMS and fibrinolytic system, the urokinase-type plasminogen activator (uPA) mRNA expression and uPA activity were detected in vitro and in vivo with semi-quantitative reverse transcription (RT)-PCR and chromogenic method. The results showed that PGMS was able to increase uPA activity in dosage-dependent manner in rat plasma, which resulted in the increase of rat fibrinolytic activity. The change of rat uPA mRNA expression with PGMS was similar to that of uPA activity. The results of experiments with cultured cells were similar to those results of experiments in vivo. The uPA mRNA expression and activities of cultured cells showed increases with PGMS in a concentration-dependent manner. All of these results indicated that PGMS may induce the expression of uPA mRNA. The increase of uPA mRNA expression may therefore reflect, in part, an increase in the stability of uPA mRNA and/or processing of nuclear uPA transcription, which, in turn, may increase the uPA activity in rat plasma and trigger the fibrinolytic system.
Pharmacological Research 03/2006; 53(2):166-70. · 4.44 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: A new xanthone glycoside (1) has been isolated from Swertia franchetiana together with five known xanthone glycosides. Their structures were elucidated as 7-O-[beta-D-xylopyranosyl-(1-->2)-beta-D-xylopyranosyl]-1,7,8-trihydroxy-3-methoxyxanthone (1), 7-O-[alpha-L-rhamnopyranosyl-(1-->2)-beta-D-xylopyranosyl]-1,7,8-trihydroxy-3-methoxyxanthone (2), 8-O-beta-D-glucopyranosyl-1,3,5,8-tetrahydroxyxanthone (3), 1-O-beta-D-glucopyranosyl-1-hydroxy-3,7,8-trimethoxyxanthone (4), 1-O-[beta-D-xylopyranosyl-(1-->6)-beta-D-glucopyranosyl]-1-hydroxy-2,3,5-trimethoxyxanthone (5) and 1-O-[beta-D-xylopyranosyl-(1-->6)-beta-D-glucopyranosyl]-1-hydroxy-3,5-dimethoxyxanthone (6) on the basis of spectroscopic evidence.
Journal of Asian Natural Products Research 05/2005; 7(2):175-9. · 0.94 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Oligochitosan is an effective inductor for plant resistance. To understand the induced resistance mechanism, mRNA differential display was used to isolate genes from Nicotiana tabacum var. Samsun NN and four enhanced-expression gene fragments were obtained and were reamplified. The reamplified products of appropriate size were isolated and purified before they were subcloned into PMD18-T vector. The results of plasmids digestion by EcoRI and HindIII and analysis of reverse Northern blot indicated that the expression of the four genes was enhanced by oligochitosan induction. Sequence and homology analysis show that they share 82% identity in nucleotide sequence with Nicotiana benthamiana SKP1 gene. Because the SKP1 protein as the core component of SCF (ubiquitin ligase enzyme E3) is relevant to plant resistance to virus, so these results suggested that oligochitosan can induce plant resistance and its mechanism may be relevant to ubiquitination.
Zhi wu sheng li yu fen zi sheng wu xue xue bao = Journal of plant physiology and molecular biology 05/2005; 31(2):213-6.
-
Article:
Note
[show abstract]
[hide abstract]
ABSTRACT: A new xanthone glycoside ( 1 ) has been isolated from Swertia franchetiana together with five known xanthone glycosides. Their structures were elucidated as 7- O -[- d -xylopyranosyl-(12)-- d -xylopyranosyl]-1,7,8-trihydroxy-3-methoxyxanthone ( 1 ), 7- O -[- l -rhamnopyranosyl-(12)-- d -xylopyranosyl]-1,7,8-trihydroxy-3-methoxyxanthone ( 2 ), 8- O- - d -glucopyranosyl-1,3,5,8-tetrahydroxyxanthone ( 3 ), 1- O- - d -glucopyranosyl-1-hydroxy-3,7,8-trimethoxyxanthone ( 4 ), 1- O -[- d -xylopyranosyl-(16)-- d -glucopyranosyl]-1-hydroxy-2,3,5-trimethoxyxanthone ( 5 ) and 1- O -[- d -xylopyranosyl-(16)-- d -glucopyranosyl]-1-hydroxy-3,5-dimethoxyxanthone ( 6 ) on the basis of spectroscopic evidence.
Journal of Asian Natural Products Research 03/2005; 7(2):175-179. · 0.94 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To study the chemical constituents from the herb of Gentianopsis paludosa.
Column chromatogrophy and spectral analysis were used to isolate and identify the constituents.
Six compounds were isolated and identified as 1,7-dihydroxy-3,8-dimethoxyxanthone (I), 1-hydroxy-3, 7, 8-trimethoxyxanthone (II), 1, 8-dihydroxy-3, 7-dimethoxyxanthone (III), 1-hydroxy-3, 7-dimethoxyxanthone (IV), beta-sitosterol (V), daucosterol (VI).
Compounds III-VI were isolated from the plant for the first time.
Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica 12/2004; 29(11):1055-6.
-
[show abstract]
[hide abstract]
ABSTRACT: To investigate the chemical constituents of Cyanotis arachnoidea.
By using chromatographic methods for separation and combination with spectral analysis, their chemical structures were determined.
Six compounds were identified as ajugasterone C-20, 22-acetonide (1), 20-hydroxyecdysone-20, 22-acetonide (2), 22-oxo-ajugasterone C (3), 22-oxo-20-hydroxyecdysone (4), beta-sitosterol (5), daucosterol (6).
Compound 3 is a new compound, 4 was a new natural compound.
Yao xue xue bao = Acta pharmaceutica Sinica 11/2003; 38(10):760-2.
-
[show abstract]
[hide abstract]
ABSTRACT: UV labeling detection has been commonly used to determine the association constants between lectins and saccharides, but the interaction is always between the labeled carbohydrates, rather than the truly underivatized carbohydrates, and lectins. In order to directly detect saccharides during the study on the interaction of glucose and its derivatives with lectins (e.g., concanavalin A), a capillary zone electrophoretic method with detection at a wavelength of 195 nm has been developed. The influences of various separation conditions including buffer concentration, pH and voltage were investigated. By using an uncoated silica capillary (50 microns i.d., 375 microns o.d., 48.5 cm of total length, and 44.0 cm to the detector) and 50 mmol/L Na2HPO(4)-50 mmol/L NaH2PO4 solution (near to the physiological pH of 7.4) as buffer, the underivatized sugars, including glucosamine, N-acetylglucosamine, glucose, and sodium gluconate, were sufficiently separated within 11 min at an applied voltage of 10 kV. On-column UV monitoring allowed the detection of these compounds at less than 4 mmol/L level, and quantification by the peak area method allowed reproducible determination of them at least at their respective concentration ranges. The method is characterized by its simplicity, rapidity, and reproducibility, and should be useful for the analysis of the interaction of glucose and its derivatives with lectins.
Se pu = Chinese journal of chromatography / Zhongguo hua xue hui 04/2002; 20(2):156-8.
-
[show abstract]
[hide abstract]
ABSTRACT: Chitosan oligomers show various biological activities. However, its molecular mechanisms remain unknown in LPS-stimulated macrophages. Here, we explored the inhibitive effects of chitosan oligomers on LPS-induced IL-6/TNF-α production in macrophages. The results indicated chitosan oligomers pretreatment effectively inhibited LPS-induced over-expression of both inflammatory cytokines. Signal transduction studies show chitosan oligomers may repress not only the phosphorylation of p38, ERK1/2, JNK, phosphatidylinositol 3-kinase (PI3K) and Akt, but also the activation of nuclear factor-κB (NF-κB) and activator protein-1 (AP-1). Furthermore, both the activation of NF-κB/AP-1 and the subsequent IL-6/TNF-α over-expression in LPS-induced macrophages are inhibited by specific p38 inhibitor (SB203580), ERK1/2 inhibitor (PD98059), JNK inhibitor (SP600125) and PI3K inhibitor (LY294002). In conclusion, our investigation suggests chitosan oligomers inhibited the elevated expression of IL-6/TNF-α in LPS-induced macrophages, regulated by MAPKs and PI3K/Akt pathways dependent on NF-κB/AP-1 activation.
Carbohydrate Polymers 84(4):1391-1398. · 3.63 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: This study aimed to investigate the inhibitive effects of chitosan oligosaccharides (COS) on tumor necrosis factor (TNF)-α-induced over-expression of vascular adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) in human umbilical vein endothelial cells (HUVECs). We found that COS effectively inhibited TNF-α-induced expression of VCAM-1 and ICAM-1 at the level of transcription and translation. Signal transduction studies suggested that COS blocked TNF-α-induced activation of NF-κB, degradation of IκBα, and phosphorylation of p38 MAPK and ERK1/2. A further investigation showed that the NF-κB activation can be partly suppressed by p38 MAPK inhibitor (SB203580) and ERK1/2 inhibitor (PD98059), which also ameliorated the mRNA expression of VCAM-1 and ICAM-1 in TNF-α-induced HUVECs. Additionally, COS decreased U937 monocyte adhesion to HUVECs induced by TNF-α. Our findings suggest that COS inhibit VCAM-1 and ICAM-1 production in activated HUVECs at least partly through the blockade of p38 and ERK1/2 signaling pathways.
Carbohydrate Polymers.
-
[show abstract]
[hide abstract]
ABSTRACT: This study aimed to investigate the protective effect of chitosan oligosaccharides (COS) on human umbilical vein endothelial cell (HUVEC) apoptosis induced by hydrogen peroxide (H2O2). We found that COS not only reversed the decrease of cell viability and proliferation activity, but ameliorated nuclear chromatin damage in H2O2-induced HUVECs. Additionally, COS contributed to the decrease of cytosolic Ca2+ level, increase of mitochondrial membrane potential, up-regulation of Bcl-2 mRNA, down-regulation of Bax mRNA, reduction of cleaved caspase-3 protein, inhibition of phosphorylated p38 mitogen-activated protein kinase (MAPK) and induction of phosphorylated Akt in HUVECs. Further, H2O2-induced caspase-3 activation could be suppressed by p38 MAPK inhibitor (SB203580) and up-regulated by phosphatidylinositol-3-kinase (PI3K) inhibitor (LY294002), indicating the involvement of p38 MAPK and PI3K/Akt signaling pathways. In conclusion, the results show that COS may effectively inhibit the H2O2-induced HUVEC apoptosis.
Carbohydrate Polymers.
