Biomedical subjects

Xun He

Publications and source records attributed to Xun He.

9 recordsLinked to original sources

PubMed2026

[Effects and mechanisms of ethanol extract of Salvia miltiorrhiza on liver fibrosis in mice].

To identify clinically advantageous TCMs for anti-hepatic fibrosis and to elucidate the effects and molecular mechanisms of Salvia miltiorrhiza ethanol extract in the intervention of liver fibrosis, this study screened high-frequency anti-hepatic fibrosis TCMs through a review of clinical literature. The S. miltiorrhiza active components, potential targets, and liver fibrosis-related disease targets were obtained using the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP), the GeneCards database, and other databases. Gene Ontology(GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment analyses were performed on the shared targets between drugs and diseases. Molecular docking was conducted to evaluate the binding affinities between key components and core targets. In animal experiments, male Kunming mice were used to establish a liver fibrosis model induced by carbon tetrachloride(CCl_4). The mice were administered low, medium, and high doses of S. miltiorrhiza ethanol extract by gavage. The liver index, as well as serum aspartate aminotransferase(AST) and alanine aminotransferase(ALT) levels, were measured. Histopathological changes in liver tissue were observed using hematoxylin-eosin(HE) staining and Masson's trichrome staining. Western blot analysis was used to detect the protein expression levels of α-smooth muscle actin(α-SMA), Collagen Ⅰ, and heat shock protein 90 alpha family class A member 1(HSP90AA1) in liver tissue. The results showed that S. miltiorrhiza was the most frequently used TCM in clinical anti-hepatic fibrosis. A total of 65 active components and 135 potential targets were identified, and 109 common targets were obtained by intersecting these with liver fibrosis-related targets. The core targets included tumor protein p53(TP53), serine/threonine protein kinase AKT1(AKT1), Jun proto-oncogene(JUN), signal transducer and activator of transcription 3(STAT3), and HSP90AA1, which were mainly enriched in pathways related to cancer, hepatitis B, and the PI3K-AKT signaling pathway. Molecular docking indicated that the main active components of S. miltiorrhiza bound stably to the core targets, with the strongest binding affinity observed for HSP90AA1. Animal experiments demonstrated that the liver index, serum ALT and AST levels, and the expression of α-SMA, Collagen Ⅰ, and HSP90AA1 in liver tissue were significantly increased in the model group, accompanied by obvious pathological manifestations of fibrosis. Compared with the model group, different dose groups of S. miltiorrhiza ethanol extract reduced the liver index and serum ALT and AST levels to varying degrees, alleviated pathological damage and collagen deposition in liver tissue, and downregulated the protein expression of α-SMA, Collagen Ⅰ, and HSP90AA1. In conclusion, S. miltiorrhiza ethanol extract exerts a significant protective effect on CCl_4-induced liver fibrosis in mice, and its mechanisms may be related to the inhibition of HSP90AA1 expression and the regulation of liver fibrosis-related signaling pathways.

Animals↗

PubMed2005

[Determination of gallic acid in Melastoma dodecandrum by RP-HPLC].

OBJECTIVE: To establish a RP-HPLC method for the determination of gallic acid in Chinese herb Melastoma dodecandrum, and to evaluate the quality of the herb. METHOD: The RP-HPLC analysis was achieved by using a Polaris C18 column and tetrahydrofuran-methanol-0.2% phosphoric acid (0.5:0.5:99) as the mobile phase, with a flow rate of 1.0 mL x min(-1), and detected by UV at 274 nm. RESULT: The content of gallic acid was from 0.020% to 0.081%, in ten groups of M. dodecandrum collected from different locations. CONCLUSION: The method is a simple, convenient and rapid. It can be used for quality evaluation of M. dodecandrum.

China↗

PubMed2005

[Study on RP-HPLC fingerprint of compound hongcao injection].

OBJECTIVE: To establish the fingerprint detecting standard of Compound Hongcao Injection by reversed phase high performance liquid chromatography. METHOD: The chromatographic conditions were as follows: an Inersil-ODS-3 column was used; the mobile phases (acetontrile and 0.1% phosphoric acid) with gradient elution; the flow rate 1.0 mL x min(-1) and the UV absorbance detection at 300 nm. RESULT: Under the same selected chromatographic conditions, the HPLC fingerprints of raw drugs and their intermediate, finished products were obtained with good separation and correlation according to the technical requirements of fingerprint on Injection of Chinese traditional medicine. CONCLUSION: 17 common peaks as well as their retention times and peak area ratios on HPLC fingerprint can be used as the important parameters of the quality control for Compound Hongcao Injection.

Chromatography, High Pressure Liquid↗

PubMed2005

[Studies on chemical constituents in herb of Polygonum orientale].

OBJECTIVE: To study the chemical constituents of the essential substance from Polygonum oriental. METHOD: Compounds were isolated with silica gel and polyamide chromatography and their structures were determined by spectral analysis and chemical evidence. RESULT: Six compounds were obtained and identified as myricitrin, luteolin, gallic acid, catechin, protocatechuic acid, p-hydroxycinnamic acid. CONCLUSION: Six compounds were isolated from P. oriental for the first time.

Flavonoids↗

PubMed2003

Compositional and 2H NMR studies of bis(benzene)chromium composites of mesoporous vanadium-niobium mixed oxides.

New mesoporous niobium oxides with 5, 10, and 15 mol% vanadium(V) doped into the walls of the structure were synthesized by the ligand-assisted templating method with an octadecylamine template. These materials were characterized by XRD, XPS, EPR, elemental analysis, and nitrogen adsorption before being treated with excess bis(benzene)chromium to give new composites with an organometallic phase in the walls. All materials were also characterized by EPR, XRD, nitrogen adsorption, XPS, SQUID magnetometry, and elemental analysis. The materials with higher percentages of vanadium absorbed more bis(benzene)chromium, because this process depends largely on the electron transfer between the organometallic and the walls of the mesostructure and vanadium(V) is a stronger oxidant than niobium(V). Conductivity studies on these materials revealed that the ratio of Cr(0) to Cr(l) in the pores was more important than the absolute Cr loading level in governing electron transport properties but that increasing the V content led to more insulating behavior regardless of the Cr concentration. Solid-state 2H NMR studies on perdeuteriobenzene analogues of these composites showed the presence of the neutral and cationic Cr species in different ratios depending on the loading. Tumbling of these species was also slow on the NMR time scale, indicating that the charge-carrying Cr species are not rapidly moving through the pore channels of the mesostructure. This suggests that the walls of the structure may play a key role in charge transfer in these composites, contrary to what was previously believed.

Journal Article↗

PubMed2003

Modulation of neural activities by enhanced local selection in the processing of compound stimuli.

The global precedence effect refers to the findings that responses are faster to a global structure than to its local parts and local responses are slowed by incongruent global information. We recorded high-density event-related potentials (ERPs) to study the role of enhanced local selection in the global precedence effect. Hierarchical stimuli were compound letters in which the local letters were either identical (homogeneous stimuli) or the central local letter was brighter than (bright stimuli) or different in color from the others (red stimuli). Subjects were asked to attend to the pop-out local letter of the red and bright stimuli during the local task whereas there was no such instruction for the homogeneous stimuli. Top-down attention to the pop-out local item weakened the global reaction time advantage and the interference effect. The enhanced local selection decreased the amplitude of an occipito-temporal negativity between 240-360 msec but increased the amplitude of a frontal-central negativity between 260-320 msec related to local processing. The incongruency between global and local letters enlarged the posterior N2 in the local condition and this effect was eliminated by enhanced local selection. These effects were evident regardless of whether the pop-out local letter was defined by color or luminance difference. The results support the proposal that distinct neural mechanisms over the posterior and anterior areas are engaged in the selection process that contributes to local processing of compound stimuli.

Adult↗

PubMed2003

[Qualitative and quantitative studies on qianliebeixi capsules].

OBJECTIVE: To establish a method of quality control on qianliebeixi capsules. METHOD: To clarify semen vaccarine by TLC, to determinate the contents of quertin and kaempferol in prepations, by HPLC. Chromatographic conditions: C18 column with METH-0.2%H3PO4(47:53) as mobile phase; the temperature of column was 40 degrees C, and quercetin was detected at 370 nm with flowing rate 1 ml/min. RESULT: The spots of semen vaccarine were clear in TLC, no interference in negative contrast. The average recovery rate of quertin was 98.9% and the RSD was 2.2%; the average recovery rate in kaempferol was 100.4% and the RSD was 1.7%. CONCLUSION: The resolution of spots were perfect in TLC, the spots were easy to distinguish, The method is simple, rapid as well as reproducible and can control the quality of qianliebeixi capsules effectively.

Adiantum↗

PubMed2002

Recent advances in synthesis and applications of transition metal containing mesoporous molecular sieves.

Work in mesoporous silica-based materials began in the early 1990s with work by Mobil. These materials had pore sizes from 20-500 A and surface areas of up to 1500 m(2) g(-1) and were synthesized by a novel liquid crystal templating approach. Researchers subsequently extended this strategy to the synthesis of mesoporous transition metal oxides, a class of materials useful in catalysis, electronic, and magnetic applications because of variable oxidation states, and populated d-bands-features not found in silicates. These materials are already showing promise in electronic and optical applications hinging on the semiconducting properties of transition metal oxides and their potential to act as electron acceptors, an important feature in the design of cathodic materials. This is the first general review of non-silicate mesoporous materials and will focus on recent advances in this area, emphasizing materials possessing unique electronic, magnetic, or optical properties. Also covered are advances in the synthesis and applications of mesostructured sulfides as well as a new class of template-synthesized platinum-based materials that show promise in heterogeneous catalysis.

Journal Article↗

PubMedDate not supplied

Cue validity and object-based attention.

In a previous study, Egly, Driver, and Rafal (1994) observed both space- and object-based components of visual selective attention. However, the mechanisms underlying these two components and the relationship between them are not well understood. In the present research, with a similar paradigm, these issues were addressed by manipulating cue validity. Behavioral results indicated the presence of both space- and object-based components under high cue validity, similar to the results of Egly et al.'s study. In addition, under low cue validity, the space-based component was absent, whereas the object-based component was maintained. Further event-related potential results demonstrated an object-based effect at a sensory level over the posterior areas of brain, and a space-based effect over the anterior region. The present data suggest that the space- and object-based components reflect mainly voluntary and reflexive mechanisms, respectively.

Adolescent↗