Chitosan oligosaccharides protect mice from LPS challenge by attenuation of inflammation and oxidative stress.

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-1ß 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.

Chitosan oligosaccharides inhibit the expression of interleukin-6 in lipopolysaccharide-induced human umbilical vein endothelial cells through p38 and ERK1/2 protein kinases.

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.

Chitosan oligosaccharides attenuate hydrogen peroxide-induced stress injury in human umbilical vein endothelial cells.

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.

[Expression of tobacco SKP1 gene induced by oligochitosan].

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.

[Study on the chemical constituents from the herb of Gentianopsis paludosa].

OBJECTIVE: To study the chemical constituents from the herb of Gentianopsis paludosa. METHOD: Column chromatogrophy and spectral analysis were used to isolate and identify the constituents. RESULT: 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). CONCLUSION: Compounds III-VI were isolated from the plant for the first time.

Successful rescuing a pregnant woman with severe hepatitis E infection and postpartum massive hemorrhage.

AIM: To sum up the experience of the successful therapy for the severe hepatitis of pregnant woman with postpartum massive hemorrhage. METHODS: The advanced therapeutic methods including the bilateral uterine artery embolism, hemodialysis and artificial liver support therapy were performed with comprehensive medical treatments and the course of the successful rescuing the patient was analyzed. RESULTS: Through the hospitalization of about two mouths the patient and her neonatus had gotten the best of care in our department and pediatric department separately. Both of them were discharged in good condition. CONCLUSION: The key points for a successful therapy of the pregnant woman with severe hepatitis are termination of the pregnancy and the control of their various complications. It was suggested that the proper combination of these measures of modern therapy would race against time for renewing of hepatic and renal functions.

[Chemical constituents of Cyanotis arachnoidea].

AIM: To investigate the chemical constituents of Cyanotis arachnoidea. METHODS: By using chromatographic methods for separation and combination with spectral analysis, their chemical structures were determined. RESULTS: 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). CONCLUSION: Compound 3 is a new compound, 4 was a new natural compound.