Response Surface Methodology for Optimizing the Ultrasound-Assisted Extraction of Polysaccharides from Acanthopanax giraldii.

The aim of this study was to investigate and optimize the most important factors affecting the extraction of Acanthopanax giraldii HARMS polysaccharides (AHPs) by ultrasound-assisted extraction (UAE) technology in a systemic manner. The ranges of four factors, including extraction temperature, liquid/solid ratio, extraction time, and ultrasonic power, were first determined by a single-factor experiment, followed by optimization of the UAE conditions using the Box-Behnken design (BBD) for maximum AHPs production. In our study, the models developed from the experimental design predicted the experimental data well and had a high determination coefficient (R2=0.9387). The optimized conditions for AHPs extraction were as follows: extraction temperature, 58°C; liquid/solid ratio, 25 : 1; extraction time, 73 min; and ultrasonic power, 85 W. Under these optimized conditions, the polysaccharide yield was 1.532±0.037% (n=3), being very close to the predicted value of 1.546% by the model. In addition, to investigate whether there was a difference of AHPs content between UAE and traditional hot water extraction (THWE), Fourier-transform (FT) IR spectral analyses was performed. The results showed that the functional groups of the polysaccharides extracted by either UAE or THWE were fundamentally identical. Furthermore, AHPs extracted by UAE could promote macrophage activation, such as enhanced phagocytosis and increased cytokine (interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α)) secretion in RAW264.7 cells. In conclusion, optimization of the UAE conditions by response surface methodology (RSM) was a promising method to improve the extraction yield of AHPs. AHPs extracted by the optimized UAE method can maintain their polysaccharide structure and biological activity.

LPA signaling is required for dopaminergic neuron development and is reduced through low expression of the LPA1 receptor in a 6-OHDA lesion model of Parkinson's disease.

Lysophosphatidic acid (LPA) is a bioactive phospholipid that activates at least five known G-protein-coupled receptors (GPCRs): LPA1-LPA5. The nervous system is a major locus for LPA1 expression. LPA has been shown to regulate neuronal proliferation, migration, and differentiation during central nervous system development as well as neuronal survival. Furthermore, deficient LPA signaling has been implicated in several neurological disorders including neuropathic pain and schizophrenia. Parkinson's disease (PD) is a neurodegenerative movement disorder that results from the loss of dopaminergic (DA) neurons in the substantia nigra pars compacta (SNc). The specific molecular pathways that lead to DA neuron degeneration, however, are poorly understood. The influence of LPA in the differentiation of mesenchymal stem cells (MSCs) into DA neurons in vitro and LPA1 expression in a 6-hydroxydopamine (6-OHDA) lesion model of PD in vivo were examined in the present study. LPA induced neuronal differentiation in 80.2 % of the MSC population. These MSCs developed characteristic neuronal morphology and expressed the neuronal marker, neuron-specific enolase (NSE), while expression of the glial marker, glial fibrillary acidic protein (GFAP), was absent. Moreover, 27.6 % of differentiated MSCs were positive for tyrosine hydroxylase (TH), a marker for DA neurons. In the 6-OHDA PD rat model, LPA1 expression in the substantia nigra was significantly reduced compared to control. These results suggest LPA signaling via activation of LPA1 may be necessary for DA neuron development and survival. Furthermore, reduced LPA/LPA1 signaling may be involved in DA neuron degeneration thus contributing to the pathogenesis of PD.

Analysis of Acanthopanax giraldii Harms Polysaccharide II Composition and Its Immune-Protective Role in a Cyclophosphamide-Induced Immunosuppressive Mice Model.

Acanthopanax giraldii Harms is commonly used in traditional Chinese medicine to treat rheumatism, improve joints, and strengthen muscles and bones. The polysaccharides present in A. giraldii Harms contain major bioactive substances, which have antioxidant, anticancer, and antiviral activities. In this study, the structural characterization of the homogeneous polysaccharide isolated from A. giraldii Harms, known as AHP-II, and its immunomodulatory effects in vivo will be studied. High-performance ion chromatography (HPIC) and high-performance gel permeation chromatography (HPGPC) based analyses revealed that AHP-II was composed of various monosaccharides, which included rhamnose, arabinose, galactose, glucose, mannose, galacturonic acid, and glucuronic acid in molar ratios of 29.5 : 24.6 : 23.8 : 4.4 : 5.7 : 8.8 : 3.1, respectively, and had a collective molecular weight of 80.21 × 103 Da. Fourier-transform infrared (FTIR) spectroscopy indicated the presence of a pyranose ring and ß-type glycosidic linkages in AHP-II. In addition, immunomodulatory effect analyses of AHP-II that used a cyclophosphamide-induced immunosuppressive mouse model demonstrated that its treatment could significantly restore spleen and thymus indices, promote the proliferation of splenic lymphocytes, elevate CD4+ T lymphocyte percentage and CD4+ : CD8+ ratio in the spleen, promote macrophage phagocytosis, and restore cytokines (IL-6, TNF-α, IgM, and IgG) levels. These results suggested that AHP-II could potentially be used as natural immunomodulator and as an alternative treatment to reduce chemotherapy-induced immunosuppression.

Psychological Stress Up-Regulates CD147 Expression Through Beta-Arrestin1/ERK to Promote Proliferation and Invasiveness of Glioma Cells.

Psychological stress is closely related to the occurrence and prognosis of various malignant tumors, but the underlying mechanisms are not well studied. CD147 has been reported to be expressed in glioma and other malignant tumors. CD147 not only participates in lactic acid transport, but it also plays an important role in the invasion and metastasis of malignant tumor cells by stimulating the production of numerous matrix metalloproteinases (MMPs) and vascular endothelial growth factor by fibroblasts, and could also act as an autocrine factor stimulating MMPs production in metastatic tumor cells. Here, we found that silencing CD147 in chronically stressed nude mice not only inhibited the proliferation of xenografts but also decreased matrix metalloproteinase-2, 9 expression and lactic acid content in tumor tissues. Furthermore, norepinephrine (NE) was significantly increased in the serum of nude mice in glioma stress model. To determine the underlying cellular mechanism, we added exogenous NE into LN229 and U87 cells to simulate the stress environment in vitro. The invasiveness of the glioma cells was subsequently examined using a Matrigel invasion assay. We demonstrated that knockdown of CD147 inhibited glioma invasiveness and metastasis with norepinephrine stimulation. Luciferase reporter gene experiments further demonstrated that the expression of CD147 is up-regulated primarily by norepinephrine via the ß-Adrenalin receptor (ßAR)-ß-arrestin1-ERK1/2-Sp1 pathway. High expression of CD147 promoted the secretion of MMP-2 and the increment of lactic acid, which accelerated the augmented invasion and metastasis of glioma induced by psychological stress. Taken together, these results suggest that psychological stress promotes glioma proliferation and invasiveness by up-regulating CD147 expression. Thus, CD147 might be a potential target site in the treatment of glioma progression induced by chronic psychological stress.

Binding of the polysaccharide from Acanthopanax giraldii Harms to toll-like receptor 4 activates macrophages.

ETHNOPHARMACOLOGICAL RELEVANCE: The traditional Chinese medicine, Acanthopanax giraldii Harms, is commonly used to treat arthralgia due to wind, cold and dampness, as well as weakness in the feet and knees. Its other reported effects include eliminating flatulence, strengthening muscles and bones, and delaying aging. The polysaccharides in A. giraldii Harms are the major bioactive substances that confer the herb's antioxidant properties as well as anticancer and antiviral effects. AIMS OF THE STUDY: To elucidate the underlying mechanism and signaling cascade involved in the homogeneous A. giraldii Harms polysaccharide II (AHP-II)-mediated immunomodulation of mice macrophages. MATERIALS AND METHODS: The phagocytosis of neutral red and the production of nitric oxide, interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α), were measured to determine AHP-II-induced macrophage activation. Confocal microscopy and flow cytometry were used to confirm the binding of AHP-II to macrophages. The involvement of Toll-like receptor (TLR) 4 in AHP-II-induced macrophage activation was demonstrated using antibody blocking and macrophages from C3H/HeJ TLR4-mutant mice. Western blotting was used to map AHP-II-induced downstream signaling pathways. RESULTS: AHP-II increased the phagocytosis of macrophages and the release of nitric oxide, IL-6 and TNF-α cytokines. Direct, saturable and reversible binding of AHP-II to macrophages was observed, while it can be inhibited by the anti-TLR4 antibody. In addition, the presence of the anti-TLR4 antibody inhibited AHP-II-induced macrophage IL-6 and TNF-α production in the peritoneal macrophages of C3H/HeJ mice. Moreover, AHP-II-TLR4-stimulated macrophages activate the downstream intracellular ERK and JNK/nuclear factor (NF)-κB signaling pathways. In addition, the AHP-II-mediated regulation of IL-6 and TNF-α production from macrophages was greatly affected by specific ERK, JNK and NF-κB inhibitors. CONCLUSION: Our study elucidated the immunomodulatory mechanism of AHP-II in macrophage activation and identified TLR4 as the main receptor coordinating AHP-II binding. Our findings suggest AHP-II may be used as a novel immunopotentiator for medical purposes.

[Psychological distress promotes proliferation and invasion of glioma by upregulating lactate deoxygenase A].

Objective To investigate the role of lactate deoxygenase A (LDHA) expression in the proliferation and invasion of glioma promoted by the psychological distress. Methods The glioma-bearing nude mice were divided into tumor bearing group, stress tumor bearing group, negative control, short hairpin RNA (shRNA)-lactate dehydrogenase A (LDHA) group and shRNA-LDHA stress group. Four weeks after stress, the tumor size of each group was measured; meanwhile, norepinephrine (NE) andadrenaline (EPI) in the blood were detected by ELISA; lactic acid in the tumor tissue was determined by colorimetry. And the expression level of LDHA was detected by Western blotting. The proliferation of glioma LN229 cells stimulated by NE was detected by CCK-8 assay and plate clone formation assay; TranswellTM assay was used to test the invasive ability of LN229 cells. The level of LDHA mRNA was detected by real-time quantitative PCR. The expressions of LDHA, ERK1/2 and hypoxia-induced factor-1α (HIF-1α) were observed using Western blotting. By constructing the reporter gene, we studied the mechanism of LDHA expression regulated by NE. Results The tumor size and the levels of EPI, NE, lactic acid and LDHA in the stress group significantly increased as compared with the tumor bearing group. After silencing LDHA, the proliferation rate and lactate content decreased. Compared with the control group, the mRNA and protein levels of LDHA in NE group was significantly elevated; the phosphorylation levels of HIF-1α and ERK1/2 was significantly raised; and cell proliferation and invasion ability were also enhanced. Promoter luciferase reporter assay confirmed that NE up-regulated the expression of LDHA by HIF-1α. Conclusion Adverse psychological stress can promote the proliferation and invasion of glioma cells by upregulating LDHA expression.

Flexible fibers wet-spun from formic acid modified chitosan.

The rigidity and low strain of chitosan fibers hindered their broader utility for biomedical applications. In present work, formic acid was employed as an efficient modifier for chitosan to prepare flexible fibers wet-spun from the formic acid modified chitosan solution. The formation of amide linkages between chitosan and formic acid was confirmed by FTIR, (13)C NMR, (1)H NMR and XRD measurements. The degree of formylation evaluated by (1)H NMR spectra was varied from 14.1% to 37.2% as a function of the reaction temperature. The results of the mechanical properties showed that the as-spun fibers exhibited an enhanced ductility with a maximum elongation at break of 21.7% compared with that spun from the chitosan dissolved in diluted acetic acid. The novel flexible chitosan fibers were anticipated to be used as comfortable wound dressing and bandages in biomedical fields.

An immunostimulatory polysaccharide (SCP-IIa) from the fruit of Schisandra chinensis (Turcz.) Baill.

A water-soluble polysaccharide named SCP-IIa was isolated from the water extract of the fruit of Schisandra chinensis (Turcz.) Baill by means of ethanol precipitation, deproteination, anion-exchange and gel-permeation chromatography. The molecular weight of SCP-IIa was ascertained via HPLC, and immuno-modulating effect was evaluated using the immunosuppressed model induced by cyclophosphamide. SCP-IIa was a homogeneous form of polysaccharide, with an average molecular weight of approximately 7700 Da. The detected parameters showed that SCP-IIa increased the thymus and spleen indices, as well as the pinocytic activity of the peritoneal macrophages in immunosuppressed mice. The splenocyte proliferation assay showed that SCP-IIa, in combination with Con A or LPS, positively affected splenocyte proliferation. Moreover, the polysaccharide promoted hemolysin formation. The results suggested that SCP-IIa was involved in immunomodulatory effects leading to the exploration for SCP-IIa as a potential immunostimulant.