Study on the secondary metabolites of grasshopper-derived fungi Arthrinium sp. NF2410.

Two new 2-carboxymethyl-3-hexyl-maleic anhydride derivatives, arthrianhydride A (1) and B (2), along with three known compounds 3-5, were isolated from the fermentation broth of a grasshopper-associated fungus Arthrinium sp. NF2410. The structures of new compounds 1 and 2 were determined based on the analysis of the HR-ESI-MS and NMR spectroscopic data. Furthermore, compounds 1 and 2 were evaluated on inhibitory activity against the enzyme SHP2 and both of them showed moderate inhibitory activity against SHP2.

Role of particle aggregates in herbal medicine decoction showing they are not useless: considering Coptis chinensis decoction as an example.

A large number of plants and fungi are homologs of medicine and food, and are used in the form of decoctions for complementary foods, dietary cures, and disease therapy in traditional medicine. Besides the widespread concern around the physiological and pharmacological actions of the active ingredients, the phase change in decoction and its influences on the active ingredients' absorption should not be ignored. Lots of particle aggregates are generated during the decoction of herbal medicine and then end up being taken together with the active ingredients. The question arises, "Is the absorption of active ingredients associated with the particle aggregates in decoction?" The present study takes the Coptis chinensis decoction (CCD), the particle aggregates in CCD (CCD-Ps), and the water-insoluble active ingredient of Berberine (Ber) as typical examples to investigate the effects of particle aggregates in herbal medicine decoction on the active ingredient absorption in the intestine and the underlying mechanisms. The CCD-Ps are mainly composed of polysaccharide, with commonly features of a hundred-nanometers size and negatively charged. A series of Coptis chinensis polysaccharide (CCP) composed particle aggregates (CCP-Ps) were self-assembled to mimic the CCD-Ps. In situ single-pass intestinal perfusion experiments exhibited that, both the CCD-Ps and CCP-Ps exhibited charge-dependent promotion on Ber absorption in the intestine, through regulating the tight junctions (TJs) between intestinal epithelia cells. Caco-2 cell monolayer model experiments revealed that the particle aggregates not only promoted paracellular Ber transport through TJs regulation but also improved the transcellular Ber transport through active transport and endocytosis. The present study provides a novel viewpoint to explain the scientific implications of herbal medicine decoction, in which the particles aggregated in decoction are not useless but rather act as an effective and important enhancer for adsorption of the active ingredients through multiple mechanisms.

Scanning electrochemical microscopy of DNA hybridization on DNA microarrays enhanced by HRP-modified SiO2 nanoparticles.

Imaging of localized hybridization of nucleic acids immobilized on a glass DNA microarray was performed by means of generation collection (GC) mode scanning electrochemical microscopy (SECM). Amine-tethered oligodeoxynucleotide probes, spotted on the glass surface, were hybridized with an unmodified target sequence and a biotinylated indicator probe via sandwich hybridization. Spots where sequence-specific hybridization had occurred were modified by streptavidin-horseradish-peroxidase-(HRP)-wrapped SiO2 nanoparticles through the biotin-streptavidin interaction. In the presence of H2O2, hydroquinone (H2Q) was oxidized to benzoquinone (BQ) at the modified spot surface through the HRP catalytic reaction, and the generated BQ corresponding to the amount of target DNA was reduced in solution by an SECM tip. With this DNA microarray, a number of genes could be detected simultaneously and selectively enough to discriminate between complementary sequences and those containing base mismatches. The DNA targets at prepared spots could be imaged in SECM GC mode over a wide concentration range (10(-7)-10(-12) M). This technique may find applications in genomic sequencing.

Qualitative and quantitative detection of DNA amplified with HRP-modified SiO2 nanoparticles using scanning electrochemical microscopy.

Qualitative and quantitative detection of DNA was achieved by a "sandwich" DNA sensor through SG/TC (substrate generation and tip collection) mode of scanning electrochemical microscopy (SECM). The "sandwich" DNA structure was formed by the hybridization of thiol-tethered oligodeoxynucleotide probes (capture probe), assembled on the gold substrate surface, with target DNA and biotinylated indicator probe. HRP (horseradish peroxidase)-wrapped SiO2 nanoparticles were linked to the sandwich structure through biotin-streptavidin interaction. Hydroquinone (H2Q) was oxidized to benzoquinone (BQ) at the modified substrate surface where sequence-specific hybridization had occurred through the HRP-catalyzed reaction in the presence of H2O2. The detection was based on the reduction of BQ generated on the modified substrate by SECM tip. For SECM imaging experiment, we structured the microsensor platform through localized desorption of 1-dodecanethiol monolayer. Approach curves were employed for quantitative detection of DNA concentration. The detection limit of complementary DNA was as low as 0.8pM. This technique is promising for the application on electrochemical DNA chip.

Effects of Huoxue huayu decoction on expression of retinal glutamate transporter in acute ocular hypertension of rats / 中华实验眼科杂志

Background Hypertension,ischemia and hypoxia induce the increase of glutamate level in eye tissue and furthermore produce excitatory damage and apoptosis of retinal ganglion cells(RGCs).At present,the study on the protection of traditional Chinese medicine on glutamate-induced retinal excitatory damage is lack.objective Present study was to explore the protective effects of Huoxue huayu decoction,a Chinese herbal recipe,on RGCs in acute ocular hypertension model. Methods Fony-five healthy clean Wistar rats were divided into three groups randomly.The acute ocular hypertension models were established in 40 Wistar rats by injecting the normal saline solution into the anterior chamber to elevate the intraocular pressure for 60 minutes.Huoxue huayu decoction of 4 ml was administered intragastrically once per day in 20 model rats.Other matched 5 normal Wistar rats served as normal control group.The rats were sacrificed on 1,3,7 and 14 days after modeling and the retinas were isolated for the histopathologieal and uhrastructure examination.Expression of glutamate transporter in the retina of acute ocular hypertension and normal rat retina were detected using quantitative real-time polymerase chain reaction.The utilization of animals followed the Association for Research in vision and Ophthalmology. Results After acute ocular hypertension.the retina thickness attenuated and the numbers of RGCs decreased under the light microscope in 1,3,7 and 14 days after modeling in comparison with normal control rats.The degradation of the organelle and edema as well as changes of cell nuclei were seen in model rats under the transmission electron microscopy.The expression of glutamate transporter mRNA in model group and glutamate transporter group was rapidly elevated in the first day (P<0.05),descended at the third days(P<0.01)and returned to the normal level 7 days later(P>0.05).Conclusion Huoxue huayu decoction can protect the retina against RGCs damage in the acute ocular hypertension by elevating the expression of glutamate transporters in retina.

Potential health impact on mice after nasal instillation of nano-sized copper particles and their translocation in mice.

The purpose of this study is to evaluate the overall toxicity of nasal instilled nanoscale copper particles (23.5 nm) in mice. Pathological examination, target organs identification, and blood biochemical assay of experimental mice were carried out in comparison with micro-sized copper particles (17 microm). However, only in the high-dose group of copper nanoparticles (40 mg/kg body weight instilled for three times in one week), the body weight of mice were retarded and significant pathological changes were observed. There were hydropic degeneration around the central vein and the spotty necrosis of hepatocytes in the liver and swelling in the renal glomerulus, while, severe lesion associated with the decreased number of olfactory cells and the dilapidated laminated structure were also observed in the olfactory bulb. The serum biochemical assay also indicated the sign of renal and hepatic lesion. However, there were no obvious pathological and physiological damages in the mice after instilling different-sized copper nanoparticles with low dose of 1 mg/kg body weight. The retention and distribution of copper in various tissues show that the liver, kidneys and olfactory bulb are the main accumulated tissues for copper particles, which were determined by high sensitive element-specific technique of ICP-MS. The copper contents of the liver, kidneys and the olfactory bulb increase significantly at the group of 40 mg/kg compared to the control group, which is in agreement with the histological changes. Therefore, the data indicate that nasal inhaled copper particles at very high dosage can translocate to other organs and tissues and further induce certain lesions. The present results are helpful to get better understanding of the risk assessment and evaluation for copper nanoparticles.