Pancreatic lipase and alpha-glucosidase inhibitors screening from Schisandra chinensis based on spectrum-effect relationship and ultra-high-performance liquid chromatography-tandem mass spectrometry.

As a traditional Chinese medicine, Schisandra chinensis has a potential weight-loss effect by delaying carbohydrate absorption and improving lipid metabolic disorders. However, its active components are still unclear and require in-depth research. In this study, the active components of Schisandra chinensis responsible for pancreatic lipase and alpha-glucosidase inhibitory activity were screened and identified based on a spectrum-effect relationship study in combination with ultra-performance liquid chromatography-tandem mass spectrometry analysis. The ultra-high-performance liquid chromatography fingerprints of 17 batches of Schisandra chinensis were established, and 14 common peaks were specified by similarity analysis. The half-maximal inhibition concentration values for pancreatic lipase and alpha-glucosidase inhibition were separately measured by enzymatic reactions. Using multivariate statistical methods including principal component analysis, partial least square analysis, and grey relational analysis, the correlation models between the peak areas of 14 common peaks and half-maximal inhibition concentration values were constructed, and the chromatographic peaks making a great contribution to efficacy were screened out. Peak1, Peak2, Peak4, Peak6, Peak9, Peak10, Peak11, and Peak13 were responsible for alpha-glucosidase inhibitory activity, while Peak1, Peak4, Peak6, Peak9, Peak10, and Peak11 for pancreatic lipase inhibitory activity. Finally, the 70% ethanol extracts of Schisandra chinensis were characterized by ultra-high-performance liquid chromatography-tandem mass spectrometry analysis, and 14 lignans were identified to further elucidate the active constituents of Schisandra chinensis. The positive results suggested the proposed strategy is simple and effective to screen active components from complex medicinal plants.

α-Glucosidase inhibitors screening from Cyclocarya paliurus based on spectrum-effect relationship and UPLC-MS/MS.

Cyclocarya paliurus is an edible and medicinal plant exhibiting significant hypoglycemic effect. However, its active components are still unclear and need further elucidation. In this research, the active components of the leaves of C. paliurus responsible for the α-glucosidase inhibitory activity were screened and identified based on a spectrum-effect relationship study in combination with ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) analysis. The 70% ethanol eluate fraction of the leaves of C. paliurus with the strongest α-glucosidase inhibitory activity was obtained after extraction and purification with macroporous resin. Their chromatographic fingerprints (15 batches) were established by UPLC analysis and 32 common peaks were specified by similarity analysis. Their IC50 values for α-glucosidase inhibition were measured by an enzymatic reaction. Several multivariate statistical analysis methods including hierarchical cluster analysis, principal component analysis, partial least square analysis and gray relational analysis were applied to explore the spectrum-effect relationship between common peaks and IC50 values, and the chromatographic peaks making a large contribution to efficacy were screened out. To further elucidate the active components of leaves of C. paliurus, the 70% ethanol eluate fraction was characterized by UPLC-MS/MS analysis, and 10 compounds were identified. This study provides a valuable reference for further research and development of hypoglycemic active components of C. paliurus.

Dopamine-polyethyleneimine co-deposition of a capillary for α-glucosidase immobilization and its application in enzyme inhibitor screening.

An online method based on CE was established to screen α-glucosidase inhibitors from traditional Tibetan medicine extracts. First, the inner wall at the inlet of capillary column was simply and effectively functionalized by dopamine-polyethyleneimine co-deposition method, which combines the adhesion property of dopamine and easy cationization of polyethyleneimine. Then α-glucosidase was rapidly immobilized on the inner wall of the capillary column by electrostatic adsorption. The inter- and intraday repeatability of the peak area of the enzymatic reaction product (p-nitrophenol) in a capillary was evaluated, and RSD% (n = 3) was 0.94% and 1.09%, respectively. Good batch-to-batch reproducibility of the peak area between different capillaries (RSD = 2.1%, n = 5) shows that the preparation method has good reproducibility. The Michaelis-Menten constant of the immobilized α-glucosidase was measured to be 1.18 mM, and the capillary column enzyme reactor retained 85.9% of initial activity after 30 cycles. Finally, it was applied to the screening of enzyme inhibitors in 20 traditional Tibetan medicine extracts. Sixteen medicines with inhibitory activity were screened out, and Rheum australe had the strongest inhibitory effect with an inhibitory rate of 83.3 ± 0.4%. These results showed that this method is effective to find potential enzyme inhibitors.

Gold Nanoparticle-Based Colorimetric and Fluorescent Dual-Mode Lateral Flow Immunoassay for SARS-CoV-2 Detection.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection caused the COVID-19 pandemic, impacting the global economy and medical system due to its fast spread and extremely high infectivity. Efficient control of the spread of the disease relies on a fast, accurate, and convenient detection system for the early screening of the infected population. Although reverse transcription-quantitative polymerase chain reaction (RT-qPCR) is the gold-standard method for SARS-CoV-2 RNA analysis, it has complex experimental procedures and relies on expensive instruments and professional operators. In this work, we proposed a simple, direct, amplification-free lateral flow immunoassay (LFIA) with dual-mode detection of SARS-CoV-2 RNA via direct visualization as well as fluorescence detection. The viral RNA was detected by the designed DNA probes to specifically hybridize with the conserved open reading frame 1ab (ORF1ab), envelope protein (E), and nucleocapsid (N) regions of the SARS-CoV-2 genome to form DNA-RNA hybrids. These hybrids were then recognized by the dual-mode gold nanoparticles (DMNPs) to produce two different readout signals. The fluorescence characteristics of different sizes of GNPs were explored. Under the optimized conditions, the LFIA presented a linear detection range of 104-106 TU/mL with a limit of detection (LOD) of 0.76, 1.83, and 2.58 × 104 TU/mL for lentiviral particles carrying SARS-CoV-2 ORF1ab, E, and N motifs, respectively, in the fluorescent mode, which was up to 10 times more sensitive than the colorimetric mode. Furthermore, the LFIA exhibited excellent specificity to SARS-CoV-2 in comparison with other respiratory viruses. It could be used to detect SARS-CoV-2 in saliva samples. The developed LFIA represents a promising and convenient point-of-care method for dual-mode, rapid detection of SARS-CoV-2, especially in the periods with high infectivity.

Iron deficiency anemia and platelet dysfunction: A comprehensive analysis of the underlying mechanisms.

AIMS: This research aimed to study the changes in platelet function and their underlying mechanisms in iron deficiency anemia. MAIN METHODS: Initially, we evaluated platelet function in an IDA mice model. Due to the inability to accurately reduce intracellular Fe2+ concentrations, we investigated the impact of Fe2+ on platelet function by introducing varying concentrations of Fe2+. To probe the underlying mechanism, we simultaneously examined the dynamics of calcium in the cytosol, and integrin αIIbß3 activation in Fe2+-treated platelets. Ferroptosis inhibitors Lip-1 and Fer-1 were applied to determine whether ferroptosis was involved in this process. KEY FINDINGS: Our study revealed that platelet function was suppressed in IDA mice. Fe2+ concentration-dependently facilitated platelet activation and function in vitro. Mechanistically, Fe2+ promoted calcium mobilization, integrin αIIbß3 activation, and its downstream outside-in signaling. Additionally, we also demonstrated that ferroptosis might play a role in this process. SIGNIFICANCE: Our data suggest an association between iron and platelet activation, with iron deficiency resulting in impaired platelet function, while high concentrations of Fe2+ contribute to platelet activation and function by promoting calcium mobilization, αIIbß3 activation, and ferroptosis.

Screening and identification of acetylcholinesterase inhibitors from Terminalia chebula fruits by immobilized enzyme on cellulose filter paper coupled with ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry and molecular docking.

With the increasing demand of new drugs for the treatment of Alzheimer's disease (AD), screening acetylcholinesterase (AChE) inhibitors from traditional Chinese medicines (TCMs) has been proved to be an effective strategy for drug discovery. In present study, a novel strategy was developed to fish out AChE inhibitors from Terminalia chebula fruits based on immobilized AChE coupled with ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) and molecular docking. For AChE immobilization, cellulose filter paper (CFP) as the carrier was modified with chitosan to be introduced to amino groups, and then AChE was modified on the amino-modified CFP through a Schiff base reaction with glutaraldehyde as a cross-linking agent. The CPF-immobilized AChE possessed advantages of a wider range for pH and temperature endurance, better storage stability, excellent reproducibility and reusability. The CPF-immobilized AChE was incubated with the extract of T. chebula fruits, and then the active components would form complexes with immobilized AChE. The complexes were further conveniently separated with inactive components by virtue of the instantaneous separation characteristic of CFP. Eventually, 25 (1-11, 13-26) potential AChE inhibitors were fished out and their structures were further identified by UPLC-QTOF-MS. Moreover, molecular docking was performed to discriminate non-specific compounds to AChE and explore binding mechanisms between potential inhibitors and AChE, and 25 compounds could be well embedded into active sites of AChE with affinities ranging from -9.9 to -6.4 kcal/mol. Inhibitory activities of screened active components on AChE were evaluated in vitro, and punicalagin, 1,3,6-tri-O-galloyl-ß-D-glucose (1,3,6-TGG), chebulinic acid and geraniin exhibited excellent AChE-inhibitory properties with IC50 values of 0.43 ± 0.03, 0.46 ± 0.02, 0.50 ± 0.03 and 0.51 ± 0.03 mM, respectively. The results indicated that the developed method was simple and efficient, and could be utilized to screen and identify potential AChE inhibitors from TCMs.

[Blood supply of the pedicle nasal septum mucosa flap of rabbit in experiment].

OBJECTIVE: To explore the blood supply of the pedicle nasal septum mucosa flap of rabbit, in order to supply the theory and experiment basis for making the pedicle nasal septum mucosa flap to repair nasal cavity and skull base defect. METHOD: Twenty rabbits corpses were induced into the experimental subject, and inject 5 ml blue ink into the external carotid artery, then longitudinal cut apart the middle head of rabbit, finally observe the blood supply of the pedicle nasal septum mucosa flap. RESULT: The blood supply of the pedicle nasal septum mucosa flap mostly come from the vessels of extremitas anterior part of nasal septum. CONCLUSION: Keep the he vessels of extremitas anterior part of nasal septum can guarantee the blood supply of mucous membrane, enhance the survival rate of nasal septum mucous membrane.

[Clinical analysis of tracheobronchial foreign bodies in children in 1276 cases].

OBJECTIVE: To investigate the effective therapy methods of foreign bodies in respiratory tract to lower its complications and the mortality rate. METHOD: Review the anesthesia methods, operation methods and therapeutic efficacy of 1276 cases of foreign body in respiratory tract and report three cases of death. RESULT: Under total intravenous anesthesia we took out foreign bodies by bronchoscope in 1197 cases and did that successfully for the first time in 1196 cases. Under aspiration anesthesia by ether we took out foreign bodies by bronchoscope in 78 cases and did that successfully for the first time in 65 cases, we took foreign bodies for the second time in 12 cases. We carried out tracheotomy in three cases. Edema of larynx was found in 12 cases among which 11 cases were under aspiration anesthesia by ether and one case was under total intravenous anesthesia. Under total intravenous anesthesia, the longest time of operation was 45 minutes, we could carry out the examination by bronchoscope for five times and no edema of larynx was found in all cases. Under aspiration anesthesia by ether, the longest time of operation was limited to 5 - 10 minutes, we could carry out the examination by bronchoscope for three times at most; otherwise, edema of larynx was very severe. Three cases died over apnea. Mortality rate is about 0.24%. CONCLUSION: Total intravenous anesthesia combined with surface anesthesia of respiratory tract mucosa is the ideal anesthesia method for taking out foreign bodies in respiratory tract by bronchoscope. It is more dangerous in cases that the foreign bodies are bean or that atelectasis is found. We should notice that the less the patients are, the more dangerous the operation is. In some cases tracheotomy is needed.

[Suffocation, an important lethal factor for otorhinolaryngological disease].

OBJECTIVE: To study the importance of supervision in respiratory tract for otorhinolaryngological disease. METHOD: Nine cases died of suffocation were reported and the causes were analyzed. In the 9 cases there were 3 cases with the foreign body in bronchus, 2 cases with the trachea bleeding, 2 cases with laryngopharyngeal tumor and 2 cases with bleeding from nasopharyngeal carcinoma. RESULT: All cases were died of suffocation. CONCLUSION: Suffocation is an important lethal factor for many otorhinolaryngological disease. Tracheotomy is a prompt and effective management for the suffocation resulting from upper respiratory tract obstruction. Tracheoscopy is the first choice for patients with lower respiratory tract obstruction. And the continuous inflating pressure with intubation in cases with trachea bleeding should be avoided.