The neuroprotective effects of phosphocreatine on Amyloid Beta 25-35-induced differentiated neuronal cell death through inhibition of AKT /GSK-3β /Tau/APP /CDK5 pathways in vivo and vitro

Alzheimer (AD) is a degenerative disease that can lead memory loss and behavioral dysfunction. Aβ protein and phosphorylation of Tau protein are related to the onset of AD. However, at present, its treatment and drugs are limited. The purpose of our study is to evaluate whether phosphocreatine (PCr) could protect neuronal injury induced by Aβ protein in vivo and in vitro through AKT/GSK-3β/Tau/APP/CDK5 pathways. Differentiated PC-12 cells were cultured with Aβ25-35 for 24 h, while the mice were injected with D-Galactose for eight weeks, both of them were pretreated with PCr for 2 h. The results showed PCr could obviously induce cells and hippocampus apoptosis using DAPI and TUNEL. PCr decreased the levels of intercellular reactive oxygen species (ROS) and malondialdehyde (MDA), and increased the activities of superoxide dismutase (SOD). Besides, the apoptosis pathway was detected using Western blot, showing that PCr could significantly reduce caspase-3, caspase-9, Bcl-2/Bax expression in vivo and in vitro. At the same time, PCr could decreased Ca²⁺ and apoptosis by Flow Cytometry in PC-12 cells. We observed that the morphological alteration of hippocampus injury was mitigated with the pretreatment of PCr. Furthermore, PCr pretreatment could decrease Aβ25-35-induced PC-12 cells apoptosis with APP cDNA transfection, which up-regulated AKT/GSK-3β/CDK5 pathways and induced Tau phosphorylation. In summary, PCr could reduce Aβ25-35 toxicity to protect neuronal cells via AKT/GSK-3β/CDK5 pathways.

Structural elucidation of a new arabinogalactan from the leaves of Nerium indicum

A polysaccharide fraction, NIB-2, was obtained from the 3% aqueous sodium carbonate extract of Nerium indicum leaves using anion-exchange chromatography and gel-permeation chromatography. It was found to be composed of rhamnose, arabinose, galactose, in the ratios of 1.0:10.4:4.4, along with 4% of galacturonic acid. The results of methylation analysis, periodate oxidation, partial acid hydrolysis, pectinase treatment, and 13C and 1H NMR spectroscopy indicate that it is mainly an arabinogalactan having a backbone of 1,6-linked beta-Galp, with branches at O-3, consisting of terminal, 1,5-, and 1,3,5-linked arabinofuranosyl residues, and a small proportion of galactosyl residues at the termini. Rhamnose and galacturonic acid arose from a contaminating rhamnogalacturonan.

[Studies on difference between sporoderm-broken and nonbroken spores of Ganoderma lucidum (Leyss. ex Fr.) Karst. by polysaccharide analysis]

OBJECTIVE

To compare the release ability of water-soluble polysaccharides in sporoderm-broken and nonbroken spores of Ganoderma lucidum, and establish a comparatively correct method for the determination and analysis of polysaccharide contents in Chinese herbs.

METHOD

The release ability of water-soluble polysaccharides was determined on the basis of phenol-sulfuric acid modification in different conditions.

RESULT

The release ability of polysaccharides of sporoderm-broken spores was much greater than that of nonbroken spores; and the phenol-sulfuric acid modified cation method proved excellent in accuracy and reproducibility, with a relative error less than 1.5%.

CONCLUSION

The spores should be wall-wracked if used as a nutriment, or for extraction and analysis of their effective components. The method can be successfully used for the determination of polysaccharide contents in Chinese herbs or nutriments.

[Studies on the polysaccharide H3 of Cuscuta chinensis Lam]

AIM

To study the structural characterization of an acidic polysaccharide, H3, isolated from the seeds of Cuscuta chinensis Lam.

METHODS

Both chemical (such as sugar component analysis, methylation analysis, reduction of uronic acid, partial acidic hydrolysis, etc.) and spectral analysis (1HNMR, 13CNMR, IR, etc.) were used to investigate the structural characterization of H3.

RESULTS

The molecular weight of H3 was estimated to be more than 1.0 x 10(6). The analytical results of sugar components indicated that H3 composed of Rha, Ara, Gal, and Gal A. Methylation analysis, partial acidic hydrolysis and 1H, 13CNMR further identified the linkages and sequence of the residues of H3.

CONCLUSION

These results suggest that H3 is a highly branched heteropolysaccharide with structure elucidation for the first time.

Chemical characterization and immunological activities of an acidic polysaccharide isolated from the seeds of Cuscuta chinensis Lam

AIM

To study chemical characterization and immunological activities of an acidic polysaccharide, CHC-1, isolated and purified from the seeds of Cuscuta chinensis Lam.

METHODS

Both chemical and spectral methods were used to investigate the chemical characterization of CHC-1. Effect of CHC-1 on the proliferation rates of T- and B-lymphocytes both in vivo and in vitro, and antibody production in vivo was measured at various concentrations of CHC-1.

RESULTS

The molecular weight of CHC-1 was estimated to be more than 1.0 x 10(6). The analytical results of sugar components indicated that CHC-1 was composed of Rha, Ara, Gal, and GalA in a molar ratio of 0.8:1.0:1.5:0.3. Methylation analysis and 1H, 13C NMR further identified the linkages of the residues of CHC-1. CHC-1 0.1 g/L promoted remarkably the proliferation of T-cells and B-cells in vitro. CHC-1 25 mg/kg, 50 mg/kg caused an evident increase in spleen weight, lymphocyte proliferation, antibody production, etc. But its effect on IgG levels was not significant.

CONCLUSION

CHC-1 is a highly branched heteropolysaccharide and possessed immune enhancement activities.

Constituents of the roots of Salvia prionitis

From the roots of Salvia prionitis, a novel alkaloid named prioline (1) and a new diterpene, prineoparaquinone (2), were isolated together with taxodione; microstegiol; 8,11,13-dehydroabietane; and 2-isopropyl-8-methyl-3,4-phenanthraquinone. The structures of the new compounds were established by spectroscopic means.

[Studies on polysaccharide from Akebia trifoliate (I)]

Crude polysaccharide ATB was extracted from the stems of Akebia trifoliate with 5% NaOH. It was then subjected to DEAE-Cellulose column chromatography and purified by Sephadex G-200 chromatography. Finally, a pure polysaccharide ATBB-2 was obtained. The molecular weight of ATBB-2 was estimated to be 2.3 x 10(5). By total acid hydrolysis, the analytical results indicated that ATBB-2 is composed of Rha, Ara, Xyl, Gal, Glc and GalA in a molar ratio of 1.22:1.00:1.10:0.85:0.24:0.82. Methylation analysis, periodate oxidation analysis, Smith degradation, partial acid hydrolysis, 1H and 13CNMR showed that ATBB-2 is a highly branched molecule without a main chain.