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1.
Eur Arch Otorhinolaryngol ; 281(4): 1735-1743, 2024 Apr.
Article in English | MEDLINE | ID: mdl-37924365

ABSTRACT

PURPOSE: To investigate the effect of the interval between bilateral cochlear implantation on the development of bilateral peripheral auditory pathways as revealed by the electrically evoked auditory brainstem response (EABR). METHODS: Fifty-eight children with profound bilateral sensorineural hearing loss were recruited. Among them, 33 children received sequential bilateral cochlear implants (CIs), and 25 children received simultaneous bilateral CIs. The bilateral EABRs evoked by electrical stimulation from the CI electrode were recorded on the day of second-side CI activation. RESULTS: The latencies of wave III (eIII) and wave V (eV) were significantly shorter on the first CI side than on the second CI side in children with sequential bilateral CIs but were similar between the two sides in children with simultaneous bilateral CIs. Furthermore, the latencies were prolonged from apical to basal channels along the cochlea in the two groups. In children with sequential CIs, the inter-implant interval was negatively correlated with the eV latency on the first CI side and was positively correlated with bilateral differences in the eIII and eV latencies. CONCLUSIONS: Unilateral CI use promotes the maturation of ipsilateral auditory conduction function. However, a longer inter-implant interval results in more unbalanced development of bilateral auditory brainstem pathways. Bilateral cochlear implantation with no or a short interval is recommended.


Subject(s)
Cochlear Implantation , Cochlear Implants , Deafness , Hearing Loss, Sensorineural , Child , Humans , Hearing Loss, Sensorineural/surgery , Evoked Potentials, Auditory, Brain Stem/physiology , Brain Stem/surgery , Deafness/surgery
2.
Crit Rev Food Sci Nutr ; : 1-23, 2023 Feb 09.
Article in English | MEDLINE | ID: mdl-36756885

ABSTRACT

Pectin is a complex polysaccharide found in plant cell walls and interlayers. As a food component, pectin is benefit for regulating intestinal flora. Metabolites of intestinal flora, including short-chain fatty acids (SCFAs), bile acids (BAs) and lipopolysaccharides (LPS), are involved in blood glucose regulation. SCFAs promote insulin synthesis through the intestine-GPCRs-derived pathway and hepatic adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) pathway to promote hepatic glycogen synthesis. On the one hand, BAs stimulate intestinal L cells and pancreatic α cells to secrete Glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) through receptors G protein-coupled receptor (TGR5) and farnesoid X receptor (FXR). On the other hand, BAs promote hepatic glycogen synthesis through AMPK pathway. LPS inhibits the release of inflammatory cytokines through Toll-like receptors (TLRs)-myeloid differentiation factor 88 (MYD88) pathway and mitogen-activated protein kinase (MAPK) pathway, thereby alleviating insulin resistance (IR). In brief, both SCFAs and BAs promote GLP-1 secretion through different pathways, employing strategies of increasing glucose consumption and decreasing glucose production to maintain normal glucose levels. Notably, pectin can also directly inhibit the release of inflammatory cytokines through the -TLRs-MYD88 pathway. These data provide valuable information for further elucidating the relationship between pectin-intestinal flora-glucose metabolism.

3.
Biochem Genet ; 2023 Oct 06.
Article in English | MEDLINE | ID: mdl-37801144

ABSTRACT

Caffeic acid transferase (COMT) is a key enzyme in the lignin and melatonin synthesis pathways and plays an important role in plant growth and development. All seed plants have two characteristics: they have vascular tissues, phloem, and xylem, and they can produce and reproduce seeds. In order to understand the distribution and evolution of COMTs in seed plants, we performed physicochemical property analysis, subcellular localization, phylogenetic analysis, conserved motif analysis, and protein interaction network analysis of 44 COMT homologs from 26 seed plants through in silico. The results showed that in seed plants, the structure of COMT genes tends to be stable in different plant taxa, while the relationship between the chromosomal positions of different COMT genes in the same plant was more intricate. The conserved distribution of COMT in seed plants reflected its highly specialized function.

4.
Drug Chem Toxicol ; : 1-9, 2023 Feb 23.
Article in English | MEDLINE | ID: mdl-36815321

ABSTRACT

OBJECTIVE: Particulate matter with an aerodynamic diameter ≤2.5 µm (PM2.5) is a public health risk. We investigate PM2.5 on metabolites in cardiomyocytes and the influence of vitamin C on PM2.5 toxicity. MATERIALS AND METHODS: For 24 hours, H9C2 were exposed to various concentrations of PM2.5 (0, 100, 200, 400, 800 µg/ml), after which the levels of reactive oxygen species (ROS) and cell viability were measured using the cell counting kit-8 (CCK-8) and 2',7'-dichlorofluoresceindiacetate (DCFH2-DA), respectively. H9C2 were treated with PM2.5 (200 µg/ml) in the presence or absence of vitamin C (40 µmol/L). mRNA levels of interleukin 6(IL-6), caspase-3, fatty acid-binding protein 3 (FABP3), and hemeoxygenase-1 (HO-1) were investigated by quantitative reverse-transcription polymerase chain reaction. Non-targeted metabolomics by LC-MS/MS was applied to evaluate the metabolic profile in the cell. RESULTS: Results revealed a concentration-dependent reduction in cell viability, death, ROS, and increased expression of caspase-3, FABP3, and IL-6. In total, 15 metabolites exhibited significant differential expression (FC > 2, p < 0.05) between the control and PM2.5 group. In the PM2.5 group, lysophosphatidylcholines (LysoPC,3/3) were upregulated, whereas amino acids (5/5), amino acid analogues (3/3), and other acids and derivatives (4/4) were downregulated. PM2.5 toxicity was lessened by vitamin C. It reduced PM2.5-induced elevation of LysoPC (16:0), LysoPC (16:1), and LysoPC (18:1). DISCUSSION AND CONCLUSIONS: PM2.5 induces metabolic disorders in H9C2 cardiomyocytes that can be ameliorated by treatment with vitamin C.

5.
Neuromodulation ; 26(3): 620-628, 2023 Apr.
Article in English | MEDLINE | ID: mdl-36307355

ABSTRACT

OBJECTIVES: Transcutaneous auricular vagus nerve stimulation (taVNS) is a promising treatment option for migraines. This study aims to investigate the modulation effects of different taVNS frequencies along the central vagus nerve pathway in migraineurs. MATERIALS AND METHODS: Twenty-four migraineurs were recruited for a single-blind, crossover magnetic resonance imaging (MRI) study. The study consisted of two taVNS MRI scan sessions, in which either 1-Hz or 20-Hz taVNS was applied in a random order. Seed-based static and dynamic functional connectivity (FC) analyses were performed using two key nodes of the vagus nerve pathway, the nucleus tractus solitarius (NTS) and the locus coeruleus (LC). RESULTS: Static FC (sFC) analysis showed that 1) continuous 1-Hz taVNS resulted in an increase of NTS/LC-occipital cortex sFC and a decrease of NTS-thalamus sFC compared with the pre-1-Hz taVNS resting state, 2) continuous 20-Hz taVNS resulted in an increase of the LC-anterior cingulate cortex (ACC) sFC compared with the pre-20-Hz taVNS resting state, 3) 1-Hz taVNS produced a greater LC-precuneus and LC-inferior parietal cortex sFC than 20 Hz, and 4) 20-Hz taVNS increased LC-ACC and LC-super temporal gyrus/insula sFC in comparison with 1 Hz. Dynamic FC (dFC) analysis showed that compared with the pre-taVNS resting state, 1-Hz taVNS decreased NTS-postcentral gyrus dFC (less variability), 20-Hz taVNS decreased dFC of the LC-superior temporal gyrus and the LC-occipital cortex. Finally, a positive correlation was found between the subjects' number of migraine attacks in the past four weeks and the NTS-thalamus sFC during pre-taVNS resting state. CONCLUSIONS: 1-Hz and 20-Hz taVNS may modulate the sFC and dFC of key nodes in the central vagus nerve pathway differently. Our findings highlight the importance of stimulation parameters (frequencies) in taVNS treatment.


Subject(s)
Migraine Disorders , Vagus Nerve Stimulation , Humans , Magnetic Resonance Imaging/methods , Migraine Disorders/diagnostic imaging , Migraine Disorders/therapy , Single-Blind Method , Vagus Nerve/physiology , Vagus Nerve Stimulation/methods , Cross-Over Studies
6.
Int J Mol Sci ; 24(4)2023 Feb 05.
Article in English | MEDLINE | ID: mdl-36834566

ABSTRACT

Hydroxyl-α-sanshool is the main alkylamide produced by Zanthoxylum armatum DC., and it is responsible for numbness after consuming Z. armatum-flavored dishes or food products. The present study deals with the isolation, enrichment, and purification of hydroxyl-α-sanshool. The results indicated that the powder of Z. armatum was extracted with 70% ethanol and then filtrated; the supernatant was concentrated to get pasty residue. Petroleum ether (60-90 °C) and ethyl acetate at a 3:2 ratio, with an Rf value of 0.23, were chosen as the eluent. Petroleum ether extract (PEE) and ethyl acetate-petroleum ether extract (E-PEE) were used as the suitable enriched method. Afterward, the PEE and E-PEE were loaded onto silica gel for silica gel column chromatography. Preliminary identification was carried out by TLC and UV. The fractions containing mainly hydroxyl-α-sanshool were pooled and dried by rotary evaporation. Lastly, all of the samples were determined by HPLC. The yield and recovery rates of hydroxyl-α-sanshool in the p-E-PEE were 12.42% and 121.65%, respectively, and the purity was 98.34%. Additionally, compared with E-PEE, the purity of hydroxyl-α-sanshool in the purification of E-PEE (p-E-PEE) increased by 88.30%. In summary, this study provides a simple, rapid, economical, and effective approach to the separation of high-purity hydroxyl-α-sanshool.


Subject(s)
Zanthoxylum , Zanthoxylum/chemistry , Silica Gel , Plant Extracts/chemistry , Chromatography
7.
Int J Mol Sci ; 24(13)2023 Jul 01.
Article in English | MEDLINE | ID: mdl-37446158

ABSTRACT

Pellicle biofilm-forming bacteria Bacillus amyloliquefaciens are the major spoilage microorganisms of soy products. Due to their inherent resistance to antibiotics and disinfectants, pellicle biofilms formed are difficult to eliminate and represent a threat to food safety. Here, we assessed linalool's ability to prevent the pellicle of two spoilage B. amyloliquefaciens strains. The minimum biofilm inhibitory concentration (MBIC) of linalool against B. amyloliquefaciens DY1a and DY1b was 4 µL/mL and 8 µL/mL, respectively. The MBIC of linalool had a considerable eradication rate of 77.15% and 83.21% on the biofilm of the two strains, respectively. Scanning electron microscopy observations revealed that less wrinkly and thinner pellicle biofilms formed on a medium supplemented with 1/2 MBIC and 1/4 MBIC linalool. Also, linalool inhibited cell motility and the production of extracellular polysaccharides and proteins of the biofilm matrix. Furthermore, linalool exposure reduced the cell surface hydrophobicity, zeta potential, and cell auto-aggregation of B. amyloliquefaciens. Molecular docking analysis demonstrated that linalool interacted strongly with quorum-sensing ComP receptor and biofilm matrix assembly TasA through intermolecular hydrogen bonds, hydrophobic contacts, and van der Waals forces interacting with site residues. Overall, our findings suggest that linalool may be employed as a potential antibiofilm agent to control food spoilage B. amyloliquefaciens.


Subject(s)
Bacillus amyloliquefaciens , Molecular Docking Simulation , Biofilms
8.
J Med Internet Res ; 24(3): e30189, 2022 03 22.
Article in English | MEDLINE | ID: mdl-35315779

ABSTRACT

BACKGROUND: Medical crowdfunding provides opportunities for individuals who lack financial resources to access the health services that they need. Despite the popularity of medical crowdfunding, the current understanding of the success of medical crowdfunding campaigns is fragmented and inadequate. OBJECTIVE: We aimed to comprehensively investigate which factors lead to the success of medical crowdfunding campaigns. METHODS: A search was conducted in PubMed, PsycINFO, Web of Science, ACM Digital Library, and ScienceDirect from 2010 to June 2020. Papers directly and indirectly related to the success of medical crowdfunding campaigns were included. Two reviewers independently extracted information on the success of medical crowdfunding campaigns. RESULTS: Our search yielded 441 articles, of which 13 met the inclusion criteria. Medical crowdfunding is increasingly attracting academic attention, and most studies leverage text analysis as their research methods; however, there is a lack of consensus on the definition of medical crowdfunding among researchers. Four categories of factors that affect the success of medical crowdfunding were identified: platforms, raisers, donors, and campaigns. CONCLUSIONS: Although some limitations exist in our systematic review, our study captured and mapped literatures of the success of medical crowdfunding campaigns systematically, which can be used as the basis for future research on this topic.


Subject(s)
Crowdsourcing , Fund Raising , Crowdsourcing/methods , Fund Raising/methods , Humans
9.
Eur Arch Otorhinolaryngol ; 279(10): 4847-4852, 2022 Oct.
Article in English | MEDLINE | ID: mdl-35247096

ABSTRACT

PURPOSE: To investigate the auditory pathway functions in deaf patients with Mondini malformation using the electrically evoked auditory brainstem response (EABR) during cochlear implantation (CI). METHODS: A total of 58 patients with severe to profound sensorineural hearing loss (SNHL) were included in this study. Of these patients, 27 cases had Mondini malformation and 31 control cases had no inner ear malformations (IEMs). Intraoperative EABRs evoked by electrical stimulation at the round window niche (RWN) and round window membrane (RWM) were recorded. RESULTS: Patients with Mondini malformation showed significantly lower EABR extraction rates than those with no IEMs did. However, for patients who showed EABRs, no significant difference in EABR thresholds, wave III (eIII) latencies, wave V (eV) latencies or eIII-eV latency intervals was found between two groups. CONCLUSION: The physiological functions of the peripheral auditory system in patients with Mondini malformation may divide into opposite extremes, as revealed by a robust EABR and the absence of the EABR, respectively. The auditory conduction function should be objectively and individually evaluated for patients with Mondini malformation by the EABR.


Subject(s)
Cochlear Implantation , Cochlear Implants , Hearing Loss, Sensorineural , Auditory Threshold , Evoked Potentials, Auditory, Brain Stem/physiology , Female , Hearing , Hearing Loss, Sensorineural/surgery , Humans , Pregnancy
10.
Int J Mol Sci ; 23(14)2022 Jul 15.
Article in English | MEDLINE | ID: mdl-35887160

ABSTRACT

Our previous study extracted and identified an antibacterial peptide that was named NP-6. Herein, we investigated the physicochemical properties of NP-6, and elucidated the mechanisms underlying its antimicrobial activity against Staphylococcus aureus. The results showed that the hemolysis activity of NP-6 was 2.39 ± 0.13%, lower than Nisin A (3.91 ± 0.43%) at the same concentration (512 µg/mL). Negligible cytotoxicity towards RAW264.7 cells was found when the concentration of NP-6 was lower than 512 µg/mL. In addition, it could keep most of its activity in fetal bovine serum. Moreover, transmission electron microscopy, confocal laser scanning microscopy, and flow cytometry results showed that NP-6 can destroy the integrity of the bacterial cell membrane and increase the membrane permeability. Meanwhile, NP-6 had binding activity with bacterial DNA and RNA in vitro and strongly inhibited the intracellular ß-galactosidase activity of S. aureus. Our findings suggest that NP-6 could be a promising candidate against S. aureus.


Subject(s)
Anti-Bacterial Agents , Staphylococcus aureus , Anti-Bacterial Agents/pharmacology , Bacteria , Cell Membrane , Microbial Sensitivity Tests , Peptides/pharmacology
11.
Int J Mol Sci ; 23(10)2022 May 22.
Article in English | MEDLINE | ID: mdl-35628620

ABSTRACT

3-PBA is a major degradation intermediate of pyrethroids. Its widespread existence in the environment poses a severe threat to the ecosystem and human health. This study evaluated the adsorption capacity of L. plantarum RS20 toward 3-PBA. Batch adsorption experiments indicated that the optimal adsorption conditions were a temperature of 37 °C and initial pH of 6.0-8.0, under which the removal rate was positively correlated with the cell concentration. In addition, there was no link between the incubation time and adsorption rate. The kinetic study showed that the adsorption process fitted well with the pseudo-second-order model, and the adsorption isotherms could be described by both Langmuir and Freundlich equations. Heat and acid treatments showed that the ability of strain RS20 in removing 3-PBA was independent of microbial vitality. Indeed, it was involved with chemisorption and physisorption via the cell walls. The cell walls made the highest contribution to 3-PBA removal, according to the adsorption experiments using different cellular components. This finding was further reconfirmed by SEM. FTIR spectroscopy analysis indicated that carboxyl, hydroxyl, amino groups, and -C-N were the functional sites for the binding of 3-PBA. The co-culture experiments showed that the adsorption of strain RS20 enhanced the degradation of 3-PBA by strain SC-1. Strain RS20 could also survive and effectively remove 3-PBA in simulated digestive juices. Collectively, strain RS20 could be employed as a biological detoxification agent for humans and animals by eliminating 3-PBA from foods, feeds, and the digestive tract in the future.


Subject(s)
Lactobacillus plantarum , Water Pollutants, Chemical , Adsorption , Benzoates , Ecosystem , Water Pollutants, Chemical/chemistry
12.
J Transl Med ; 19(1): 354, 2021 08 17.
Article in English | MEDLINE | ID: mdl-34404427

ABSTRACT

BACKGROUND: A growing body of evidence suggests that transcutaneous auricular vagus nerve stimulation (taVNS) may relieve symptoms of migraineurs. Frequency is one of the key stimulation parameters. The aim of this study is to investigate the modulation effect of taVNS frequency on the descending pain modulation system (DPMS) in patients with migraine. METHODS: Twenty-four episodic migraineurs without aura (21 females) were recruited for the single-blind, crossover, functional magnetic resonance imaging (fMRI) study. Each participant attended two separate fMRI scan sessions, one for 1 Hz and another for 20 Hz taVNS, in a random order. Seed-based functional connectivity analysis was applied using the ventrolateral periaqueductal gray (PAG) as the region of interest. RESULTS: Compared with the pre-taVNS resting state, continuous 1 Hz taVNS (during) produced a significant increase in functional connectivity between the PAG and the bilateral middle cingulate cortex (MCC), right precuneus, left middle frontal gyrus (MFG), and left cuneus. Compared with 20 Hz taVNS, 1 Hz taVNS produced greater PAG connectivity increases with the MCC, right precuneus/posterior cingulate cortex, left insula, and anterior cingulate cortex (ACC). A significant negative correlation was observed between the number of migraine attacks in the previous 4 weeks and the PAG-MCC functional connectivity in the pre-taVNS resting-state before 1 Hz taVNS. CONCLUSIONS: Our findings suggest that taVNS with different frequencies may produce different modulation effects on the descending pain modulation system, demonstrating the important role of stimulation frequency in taVNS treatment.


Subject(s)
Migraine Disorders , Transcutaneous Electric Nerve Stimulation , Vagus Nerve Stimulation , Female , Humans , Magnetic Resonance Imaging , Migraine Disorders/therapy , Periaqueductal Gray , Single-Blind Method
13.
Angew Chem Int Ed Engl ; 60(9): 4619-4624, 2021 Feb 23.
Article in English | MEDLINE | ID: mdl-33270973

ABSTRACT

The electrochemical three-component assembly of isoquinolines has been accomplished by ruthenaelectro-catalyzed C-H/N-H functionalization. The robustness of the electrocatalysis was reflected by an ample substrate scope, an efficient electrooxidation, and an operationally friendly procedure. The isolation of key intermediates and detailed mechanistic studies, including unprecedented cyclovoltammetric analysis of a seven-membered ruthenacycle, provided support for an unusual ruthenium(II/III/I) regime.

14.
Angew Chem Int Ed Engl ; 60(52): 27005-27012, 2021 12 20.
Article in English | MEDLINE | ID: mdl-34665924

ABSTRACT

Herein, we disclose osmaelectrocatalyzed C-H activations that set the stage for electrooxidative alkyne annulations by benzoic acids. The osmium electrocatalysis enables site- and chemoselective electrooxidative C-H activations with unique levels of selectivity. The isolation of unprecedented osmium(0) and osmium(II) intermediates, along with crystallographic characterization and analyses by spectrometric and spectroscopic in operando techniques delineate a synergistic osmium redox catalyst regime. Detailed mechanistic studies revealed a facile C-H cleavage, which allows for an ample substrate scope, providing provide robust and user-friendly access to annulated heterocycles.

15.
Angew Chem Int Ed Engl ; 60(24): 13264-13270, 2021 Jun 07.
Article in English | MEDLINE | ID: mdl-33651910

ABSTRACT

Rhodium-electrocatalyzed arene C-H oxygenation by weakly O-coordinating amides and ketones have been established by bimetallic electrocatalysis. Likewise, diverse dihydrooxazinones were selectively accessed by the judicious choice of current, enabling twofold C-H functionalization. Detailed mechanistic studies by experiment, mass spectroscopy and cyclovoltammetric analysis provided support for an unprecedented electrooxidation-induced C-H activation by a bimetallic rhodium catalysis manifold.

16.
Neural Plast ; 2020: 8870589, 2020.
Article in English | MEDLINE | ID: mdl-33381165

ABSTRACT

Background: A growing body of evidence suggests that both auricular acupuncture and transcutaneous auricular vagus nerve stimulation (taVNS) can induce antinociception and relieve symptoms of migraine. However, their instant effects and central treatment mechanism remain unclear. Many studies proved that the amygdalae play a vital role not only in emotion modulation but also in pain processing. In this study, we investigated the modulation effects of continuous taVNS at acupoints on the FC of the bilateral amygdalae in MwoA. Methods: Thirty episodic migraineurs were recruited for the single-blind, crossover functional magnetic resonance imaging (fMRI) study. Each participant attended two kinds of eight-minute stimulations, taVNS and sham-taVNS (staVNS), separated by seven days in random order. Finally, 27 of them were included in the analysis of seed-to-voxel FC with the left/right amygdala as seeds. Results: Compared with staVNS, the FC decreased during taVNS between the left amygdala and left middle frontal gyrus (MFG), left dorsolateral superior frontal gyrus, right supplementary motor area (SMA), bilateral paracentral lobules, bilateral postcingulum gyrus, and right frontal superior medial gyrus, so did the FC of the right amygdala and left MFG. A significant positive correlation was observed between the FC of the left amygdala and right SMA and the frequency/total time of migraine attacks during the preceding four weeks. Conclusion: Continuous taVNS at acupoints can modulate the FC between the bilateral amygdalae and pain-related brain regions in MwoA, involving the limbic system, default mode network, and pain matrix, with obvious differences between the left amygdala and the right amygdala. The taVNS may produce treatment effects by modulating the abnormal FC of the amygdala and pain networks, possibly having the same central mechanism as auricular acupuncture.


Subject(s)
Amygdala/diagnostic imaging , Migraine without Aura/therapy , Nerve Net/diagnostic imaging , Vagus Nerve Stimulation/methods , Acupuncture Points , Adult , Amygdala/physiopathology , Cross-Over Studies , Female , Humans , Magnetic Resonance Imaging , Male , Migraine without Aura/diagnostic imaging , Single-Blind Method , Young Adult
17.
Appl Microbiol Biotechnol ; 103(5): 2217-2228, 2019 Mar.
Article in English | MEDLINE | ID: mdl-30623204

ABSTRACT

Antimicrobial peptides (AMPs) have generated growing attention because of the increasing bacterial resistance. However, the discovery and identification of AMPs have proven to be challenging due to the complex purification procedure associated with conventional methods. For the reasons given above, it is necessary to explore more efficient ways to obtain AMPs. We established a new method for discovery and identification of novel AMPs by proteomics and bioinformatics from Zanthoxylum bungeanum Maxim seeds protein hydrolysate directly. This process was initially achieved by employing ultra-performance liquid chromatography-electrospray ionization-mass spectrometry/mass (UPLC-ESI-MS/MS) spectrometry to identify peptides derived from Z. bungeanum Maxim seed protein hydrolysates. Three online servers were introduced to predict potential AMPs. Sixteen potential AMPs ranging from 1.5 to 2.7 kDa were predicted and chemically synthesized, one of which, designated NP-6, inhibited activity against all the tested strains according to antimicrobial assay. Time-killing assay indicated that NP-6 could quickly kill almost all the Escherichia coli within 180 min and Staphylococcus aureus at 360 min. Moreover, the simulation 3D structure of NP-6 was consisted of α-helix and random coil, and this was verified by circular dichroism (CD) spectra. At last, the scanning electron microscope (SEM) images of E. coli and S. aureus treated by NP-6 demonstrated that NP-6 had a significant effect on bacteria cell morphology. Our findings provide an efficient approach for discovery of AMPs, and Z. bungeanum Maxim seeds may be a nature resource to extract antimicrobial agents.


Subject(s)
Antimicrobial Cationic Peptides/chemistry , Antimicrobial Cationic Peptides/pharmacology , Escherichia coli/drug effects , Seeds/chemistry , Staphylococcus aureus/drug effects , Zanthoxylum/chemistry , Chromatography, High Pressure Liquid , Computational Biology/methods , Drug Discovery/methods , Microbial Sensitivity Tests , Protein Hydrolysates/analysis , Protein Hydrolysates/pharmacology , Spectrometry, Mass, Electrospray Ionization , Tandem Mass Spectrometry
18.
Appl Microbiol Biotechnol ; 103(16): 6593-6604, 2019 Aug.
Article in English | MEDLINE | ID: mdl-31286166

ABSTRACT

A novel antimicrobial peptide named NP-6 was identified in our previous work. Here, the mechanisms of the peptide against Escherichia coli (E. coli) were further investigated, as well as the peptide's resistance to temperature, pH, salinity, and enzymes. The transmission electron microscopy (TEM), confocal laser scanning microcopy (CLSM), and flow cytometric (FCM) analysis, combined with measurement of released K+, were performed to evaluate the effect of NP-6 E. coli cell membrane. The influence of NP-6 on bacterial DNA/RNA and enzyme was also investigated. The leakage of K+ demonstrated that NP-6 could increase the permeability of E. coli cell membrane. The ATP leakage, FCM, and CLSM assays suggested that NP-6 caused the disintegration of bacterial cell membrane. The TEM observation indicated that NP-6 could cause the formation of empty cells and debris. Besides, the DNA-binding assay indicated that NP-6 could bind with bacterial genomic DNA in a way that ethidium bromide (EB) did, and suppress the migration of DNA/RNA in gel retardation. Additionally, NP-6 could also affect the activity of ß-galactosidase. Finally, the effect of different surroundings such as heating, pH, ions, and protease on the antimicrobial activity of NP-6 against E. coli was also investigated. Results showed that the peptide was heat stable in the range of 60~100 °C and performed well at pH 6.0~8.0. However, the antimicrobial activity of NP-6 decreased significantly in the presence of Mg2+/Ca2+, and after incubation with trypsin/proteinase K. The results will provide a theoretical support in the further application of NP-6.


Subject(s)
Antimicrobial Cationic Peptides/pharmacology , Cell Membrane/drug effects , Escherichia coli/drug effects , Permeability/drug effects , Antimicrobial Cationic Peptides/chemistry , Antimicrobial Cationic Peptides/isolation & purification , Cell Membrane/ultrastructure , DNA, Bacterial/metabolism , Drug Stability , Escherichia coli/ultrastructure , Hydrogen-Ion Concentration , Microbial Viability/drug effects , Protein Binding , Salinity , Seeds/chemistry , Temperature , Zanthoxylum/chemistry , beta-Galactosidase/antagonists & inhibitors
20.
Chemistry ; 23(55): 13696-13703, 2017 Oct 04.
Article in English | MEDLINE | ID: mdl-28707806

ABSTRACT

Dye-containing wastewater has caused serious environmental pollution. Herein, rationally designed spherical polyelectrolyte brushes (SPBs) with cationic charges, polystyrene-poly(2-aminoethylmethacrylate hydrochloride) (PS-PAEMH) as the absorbent, and compressed carbon dioxide as the antisolvent are proposed for the separation of the anionic dye eosin Y (EY) from a solution of mixed dyes. The adsorption behavior of EY onto PS-PAEMH was highly dependent on CO2 pressure, contact time, and initial concentration. The maximum adsorption capacity of PS-PAEMH was 335.20 mg g-1 . FTIR and UV/Vis measurements proved that the electrostatic interactions between EY and PS-PAEMH played an important role in the absorbance process. The adsorption process fitted the pseudo-second-order kinetic model and Freundlich isotherm model very well. The combined dye and polymer brush could be easily separated through ion exchange by adding an aqueous solution of NaCl. Recovered PS-PAEMH retained a high adsorption capacity even after ten cycles of regeneration. This method provides a simple and effective way to separate ionic materials for environmental engineering.

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