Hemin-porous g-C3N4 hybrid nanosheets as an efficient peroxidase mimic for colorimetric and visual determination of glucose.

A method is described for colorimetric determination of glucose by using hemin-porous graphitic carbon nitride (g-C3N4) hybrid nanosheets as a peroxidase mimic. The porous g-C3N4 nanosheets were prepared by a combination of one-pot self-polymerization, pyrolysis and liquid-phase exfoliation. The hemin-porous g-C3N4 hybrid nanosheets were prepared via in-situ deposition. It is shown that the hybrid composite has improved dispersibility, stability, and peroxidase-mimicking activity in the 3,3',5,5'-tetramethylbenzidine (TMB)/H2O2 system. This is deemed to be the result of the synergistic effect of hemin and porous g-C3N4 nanosheets. Based on these advantages of the nanosheets, a simple, low-cost, sensitive and selective colorimetric method was established for the determination of glucose at pH values around 7. Best performed at a wavelength of 652 nm, the assay has a linear response in the 10.0 µM to 500 µM glucose concentration range (R2 = 0.9942) and a 1.94 µM limit of detection. This method was successfully applied to the determination of glucose in (spiked) human serum samples. In our perception, the hybrid is a robust peroxidase mimic for use in POx-based assays as needed in medical diagnosis and environmental analysis. Graphical abstract Schematic presentation of the process of hemin-porous g-C3N4 hybrid nanosheets catalyzing the oxidation of peroxidase chromogenic substrate tetramethylbenzidine (TMB) in the presence of H2O2. The material was applied in colorimetric and visual determination of H2O2 and glucose.

Mendelian Randomization Reveals No Causal Association Between Periodontitis and Infective Endocarditis.

OBJECTIVES: Clarifying the uncertain causal relationship between periodontitis and infective endocarditis using Mendelian randomization analysis, given their historically perceived association and clinical significance. METHODS: Genetic variation data for acute periodontitis, chronic periodontitis, aggressive periodontitis, and infective endocarditis were obtained from published GWAS in individuals of European ancestry. Instrumental variables significantly associated with periodontitis were selected and univariable Mendelian randomization was conducted to infer the causal association between periodontitis and infective endocarditis. Multivariable Mendelian randomization was also performed to adjust for potential confounders including smoking, drinking, diabetes, and education. RESULTS: Our analysis found no evidence of a causal association between periodontitis and infective endocarditis, with odds ratios (ORs) of 0.992 (95% CI: 0.879-1.120), 0.947 (95% CI: 0.738-1.214), and 1.056 (95% CI: 0.916-1.217) for acute periodontitis, chronic periodontitis, aggressive periodontitis, respectively. The robustness of our findings was confirmed by heterogeneity tests, pleiotropy tests, leave-one-out analyses, and MR-PRESSO. In the multivariable MR analysis, adjusting for smoking, drinking, diabetes, and education, the overall patterns between genetic liability to periodontitis and infective endocarditis remained consistent (all P > .05). CONCLUSION: Our findings indicate that there is no genetic causal association between periodontitis and infective endocarditis.

Spatially confined CuFe2O4 nanosphere in N/O-codoped porous carbon mimetics for triple-mode sensing of antibiotics and visual detection of neurotransmitters in biofluids.

BACKGROUND: Carbon-based nanozymes have recently received enormous concern, however, there is still a huge challenge for inexpensive and large-scale synthesis of magnetic carbon-based "Two-in-One" mimics with both peroxidase (POD)-like and laccase-like activities, especially their potential applications in multi-mode sensing of antibiotics and neurotransmitters in biofluids. Although some progresses have been made in this field, the feasibility of biomass-derived carbon materials with both POD-like and laccase-like activities by polyatomic doping strategy is still unclear. In addition, multi-mode sensing platform can provide a more reliable result because of the self-validation, self-correction and mutual agreement. Nevertheless, the use of magnetic carbon-based nanozyme sensors for the multi-mode detection of antibiotics and neurotransmitters have not been investigated. RESULTS: We herein report a shrimp shell-derived N, O-codoped porous carbon confined magnetic CuFe2O4 nanosphere with outstanding laccase-like and POD-like activities for triple-mode sensing of antibiotic d-penicillamine (D-PA) and chloramphenicol (CPL), as well as colorimetric detection of neurotransmitters in biofluids. The magnetic CuFe2O4/N, O-codoped porous carbon (MCNPC) armored mimetics was successfully fabricated using a combined in-situ coordination and high-temperature crystallization method. The synthesized MCNPC composite with superior POD-like activity can be used for colorimetric/temperature/smartphone-based triple-mode detection of D-PA and CPL in goat serum. Importantly, the MCNPC nanozyme can also be used for colorimetric analysis of dopamine and epinephrine in human urine. SIGNIFICANCE: This work not only offered a novel strategy to large-scale, cheap synthesize magnetic carbon-based "Two-in-One" armored mimetics, but also established the highly sensitive and selective platforms for triple-mode monitoring D-PA and CPL, as well as colorimetric analysis of neurotransmitters in biofluids without any tanglesome sample pretreatment.

Biotemplated fabrication of N/O co-doped porous carbon confined spinel NiFe2O4 heterostructured mimetics for triple-mode sensing of antioxidants and ameliorating packaging properties.

In this work, shrimp shell-derived magnetic NiFe2O4/N, O co-doped porous carbon nanozyme with superior oxidase (OXD)-like activity was prepared and used for colorimetric/photothermal/smartphone dual-signal triple-mode detection of antioxidants in fruits and beverages. The magnetic NiFe2O4/N, O co-doped porous carbon (MNPC) material was triumphantly fabricated using a combined in-situ surface chelation and pyrolysis method. The resultant MNPC composite exhibits a superior OXD-like activity, which can effectively oxidize 3,3',5,5'-tetramethylbenzidine (TMB) for yielding colorimetric/temperature dual-signal (CTDS) in absence of H2O2. This CTDS output sensor was successfully used for the determination of ascorbic acid and tannic acid. The proposed CTDS sensor with good specificity and high sensitivity can satisfy different on-site analysis requirements. Interestingly, the MNPC as a sustainable filler was further used for improving packaging properties of polyvinyl alcohol film. In short, this work offers a large-scale and cheap method to fabricate magnetic carbon-based nanozyme for monitoring antioxidants and ameliorating packaging properties.

Microwave-assisted one-step extraction-derivatization for rapid analysis of fatty acids profile in herbal medicine by gas chromatography-mass spectrometry.

A rapid and practical microwave-assisted one-step extraction-derivatization (MAED) method was developed for gas chromatography-mass spectrometry analysis of fatty acids profile in herbal medicine. Several critical experimental parameters for MAED, including reaction temperature, microwave power and the amount of derivatization reagent (methanol), were optimized with response surface methodology. The results showed that the chromatographic peak areas of total fatty acids and total unsaturated fatty acids content obtained with MAED were markedly higher than those obtained by the conventional Soxhlet or microwave extraction and then derivatization method. The investigation of kinetics and thermodynamics of the derivatization reaction revealed that microwave assistance could reduce activation energy and increase the Arrhenius pre-exponential factor. The MAED method simplified the sample preparation procedure, shortened the reaction time, but improved the extraction and derivatization efficiency of lipids and reduced ingredient losses, especially for the oxidization and isomerization of unsaturated fatty acids. The simplicity, speed and practicality of this method indicates great potential for high throughput analysis of fatty acids in natural medicinal samples.

Study on the PEG-based microwave-assisted extraction of flavonoid compounds from persimmon leaves.

A method for PEG-based microwave-assisted extraction (MAE) of flavonoid compounds from persimmon leaves has been successfully developed. The extraction efficiency of total flavonoid content was evaluated by the chromatographic peak areas of quercetin and kaempferol, which are two bioactive components typically found in persimmon leaves. The best combination of extraction parameters was obtained with response surface methodology. A microwave power of 525 W, liquid to solid ratio of 17:1 mL/g, and PEG aqueous solution concentration of 60% w/w were identified as the optimum parameters. Extraction dynamics analysis indicated that the quercetin, kaempferol, and total flavonoid contents were rising with increasing extraction time up to 20-25 min, from which point onwards they all decreased. Under the optimum conditions, quercetin, kaempferol, and total flavonoid contents obtained from the sample were 1.20 ± 0.05, 0.64 ± 0.11, and 16.90 ± 0.06 mg/g, respectively. Compared with ethanol-based MAE, and ethanol-based and PEG-based ultrasonic-assisted extractions, PEG-based MAE had higher efficiency for the extraction of flavonoid compounds from persimmon leaves. Overall, PEG-based MAE represents an efficient choice for the extraction of bioactive substances from traditional Chinese medicines.

Recent advances in ultrasound-controlled fluorescence technology for deep tissue optical imaging.

Fluorescence imaging is a noninvasive and dynamic real-time imaging technique; however, it exhibits poor spatial resolution in centimeter-deep tissues because biological tissues are highly scattering media for optical radiation. The recently developed ultrasound-controlled fluorescence (UCF) imaging is a novel imaging technique that can overcome this bottleneck. Previous studies suggest that the effective contrast agent and sensitive imaging system are the two pivotal factors for generating high-resolution UCF images ex vivo and/or in vivo. Here, this review highlights the recent advances (2015-2020) in the design and synthesis of contrast agents and the improvement of imaging systems to realize high-resolution UCF imaging of deep tissues. The imaging performances of various UCF systems, including the signal-to-noise ratio, imaging resolution, and imaging depth, are specifically discussed. In addition, the challenges and prospects are highlighted. With continuously increasing research interest in this field and emerging multidisciplinary applications, UCF imaging with higher spatial resolution and larger imaging depth may be developed shortly, which is expected to have a far-reaching impact on disease surveillance and/or therapy.

Effects of Carboxyl or Amino Group Modified InP/ZnS Nanoparticles Toward Simulated Lung Surfactant Membrane.

Quantum dots (QDs) as a promising optical probe have been widely used for in vivo biomedical imaging; especially enormous efforts recently have focused on the potential toxicity of QDs to the human body. The toxicological effects of the representative InP/ZnS QDs as a cadmium-free emitter are still in the early stage and have not been fully unveiled. In this study, the DPPC/DPPG mixed monolayer was used to simulate the lung surfactant monolayer. The InP/ZnS-COOH QDs and InP/ZnS-NH2 QDs were introduced to simulate the lung surfactant membrane's environment in the presence of InP/ZnS QDs. The effects of InP/ZnS QDs on the surface behavior, elastic modulus, and stability of DPPC/DPPG mixed monolayer were explored by the surface pressure-mean molecular area isotherms and surface pressure-time curves. The images observed by Brewster angle microscope and atomic force microscope showed that the InP/ZnS QDs affected the morphology of the monolayer. The results further demonstrated that the InP/ZnS QDs coated with different surface groups can obviously adjust the mean molecular area, elastic modulus, stability, and microstructure of DPPC/DPPG mixed monolayer. Overall, this work provided useful information for in-depth understanding of the effects of the -COOH or -NH2 group coated InP/ZnS QDs on the surface of lung surfactant membrane, which will help scientists to further study the physiological toxicity of InP/ZnS QDs to lung health.

[Analysis of the survival in patients after surgical resection of thoracic esophageal cancer].

OBJECTIVE: To investigate the prognostic factors and influence of the number of lymph node metastases on survival and UICC-TNM classification in patients with thoracic esophageal cancer after curative resection. METHODS: From 1985 to 1990, 1224 patients were surgically treated for thoracic esophageal cancer. The patients who died within 30 days after operation were not included in this study. Fifteen factors possibly influencing survival of these patients were selected and analyzed. A multivariate analysis of these individual variables was performed by Cox proportional hazard model. According to the number of lymph node metastases (0, 1 and > or = 2), a new modification of the TNM classification was suggested: stage IIa (T2N0M0 and T3N0M0), stage IIb [T1N1M0 and T2N1(1)M0], stage IIIa [T2N1 (2)M0 and T3N1 (1) M0] and stage IIIb [T3N1 (2) M0 and T4N any M0]. RESULTS: According to multivariate analysis, lymph node metastases, depth of invasion, location of tumor, histological classification and length of the tumor were of prognostic significance (P < 0.01). There was obvious correlation between the rate of lymph node metastasis and the depth of invasion, length of tumor and grade of differentiation. The 5-year survival rate of the patients with 0, 1 and > or = 2 positive metastatic lymph nodes was 59.1%, 32.0% and 8. 9%, respectively. The 5-year survival rate of the patients with stage T2N1 M0 and stage T3N1 M0 was significantly higher in those with only one lymph node involved than in those with two or more lymph nodes involved (43.1% vs. 18.0% and 28.0% vs. 9.6%, P < 0.01). The 5-year survival rate of the modified stage IIa, IIb, IIIa and IIIb was 56.5%, 43.9%, 25.6% and 11.1%, respectively, with a statistically significant difference among different stages (P < 0.01). CONCLUSION: The lymph node metastasis is the most important prognostic factor for thoracic esophageal cancer after resection. The major influencing factors of lymph node metastasis are the depth of invasion, length of tumor and grade of differentiation. Therefore, the lymphadenectomy along with esophagectomy and subsequently combined modality therapy against lymph node metastasis is necessary to improve the 5-year survival rate. Our proposed new classification based on number of lymph node metastases (0, 1, > or = 2 positive nodes) is more applicable because it can well reflect the correlation between lymph node metastasis and the survival, and provides evidence for the modification of the currently used UICC TNM staging system for surgically treated thoracic esophageal cancer.

[Influence of glucagon-like peptide-2 on intestinal lymphocyte homing in mice with acute pancreatitis].

OBJECTIVE: To investigate the influence of glucagon-like peptide-2 (GLP-2) on intestinal lymphocyte homing receptor-integrin alpha 4 beta 7 and homing ligand-intestinal mucosal addressin cell adhesion molecule-1 (MAdCAM-1) in mice with acute pancreatitis (AP). METHODS: A total of 96 mice were divided into three groups randomly (n=32 in each group): AP group, GLP-2 group and control group. Murine AP model was reproduced by intraperitoneal injection of caerulein and lipopolysaccharides (LPS). GLP-2 (250 microg/kg) was injected intraperitoneally at 15 minutes after the establishment of model, then it was injected twice a day for 3 days in GLP-2 group, while the mice in control group received normal saline instead. Mice were sacrificed at 6, 12, 24 and 48 hours after reproduction of AP, and tissue specimens were harvested. Integrin alpha 4 beta 7 positive peripheral blood lymphocytes were determined by flow cytometry. The expression of MAdCAM-1 in the terminal ileum mucosa and Peyer patch was measured by immunohistochemistry. Same observations were also done in the control and GLP-2 groups. RESULTS: Compared with control group, integrin alpha 4 beta 7 positive lymphocyte in peripheral blood and the expression of MAdCAM-1 in the terminal ileum mucosa and Peyer patch were significantly reduced at 6, 12, 24 and 48 hours in AP mice (all P<0.05). Integrin alpha 4 beta 7 positive lymphocyte and the expression of MAdCAM-1 were markedly higher in GLP-2 group than those in AP group (all P<0.05), but were lower in GLP-2 group than those in control group (all P>0.05). CONCLUSION: Administration of GLP-2 may restore expression of integrin alpha 4 beta 7 and MAdCAM-1, promote lymphocyte homing to intestine, thus improve the immunological function of intestine.

Combined magnetic porous molecularly imprinted polymers and deep eutectic solvents for efficient and selective extraction of aristolochic acid I and II from rat urine.

Aristolochia and related plants contain nephrotoxins and mutagens in the form of aristolochic acids (AAs). However, there is still lack of a fast and specific method for monitoring AAs in biological samples. Herein, we synthesized a hybrid magnetic mesoporous carbon-molecularly imprinted polymers (MMC@MIPs) as a novel magnetic solid-phase extraction (MSPE) adsorbent for selective recognition of aristolochic acid I and II from rat urine samples. The choline chloride/glycol-based deep eutectic solvent (DES) and indomethacin were used as the eluent and dummy template molecule accordingly. The morphology, structure property and surface groups of the prepared materials were investigated in sequence, and the optimum conditions of the MMC@MIPs-MSPE procedure were also optimized well. Results showed that the proposed method had a relatively satisfactory recovery (86.7-94.3%), with low standard deviation (<4.85%) and acceptable correlation coefficients (0.991-0.996). Overall, this work not only provides an inexpensive and eco-friendly method to fabricate MMC@MIPs, but also develops a highly promising approach for the detection of aristolochic acid I and II in biological samples.

[Protective effect of urinary trypsin inhibitor on injury after intestinal ischemia-reperfusion: experiment with rats].

OBJECTIVE: To investigate the mechanism of the injury of intestinal mucosal induced by intestinal ischemia-reperfusion and the protect effects of Urinary Trypsin Inhibitor (UTI). METHODS: Thirty male Wistar rats were randomly divided into three groups, the sham operation group (SO), ischemia 45 minutes and reperfusion 6 hours group (I/R), UTI-treated group (UTI). Using clamping and then releasing the superior mesenteric artery the model of intestinal ischemia-reperfusion in rats was made. UTI group was given UTI 2 x 10(4) U/KG by administering intravenously before 30 minutes of operation, while the group SO and I/R were intravenously injected with saline. Blood, intestinal tissue and lymph node were obtained after 6 hours of reperfusion. The level of intestinal fatty acid binding protein (IFABP), Tumor Necrosis Factor-alpha (TNF-alpha), Nitric Oxide (NO), malondialdehyde (MDA), superoxide dismutase (SOD), myeloperoxidase (MPO) and the rate of bacterial translocation (BT) in each group were examined. Intestinal tissue samples were also taken for histological analysis by light microscopy and electron microscopy. RESULTS: The content of IFABP, TNF-alpha, NO, MDA and MPO were significantly lower in group UTI than in group I/R [IFABP (520.87 +/- 75.41) pg/ml vs (493.57 +/- 136.35) pg/ml, NO (58.97 +/- 7.06) micromol/L vs (95.15 +/- 9.13) micromol/L, TNF-alpha (15.38 +/- 1.70) pg/ml to (23.55 +/- 4.34) pg/ml, MDA (4.5 +/- 1.1) nmol/mg vs (9.2 +/- 2.6) nmol/mg, MPO (1.98 +/- 0.22) U/g vs (3.02 +/- 0.55) U/g, SOD (77.08 +/- 7.14) U/mg vs (60.61 +/- 6.83) U/mg, P < 0.01]. There was significant difference in the rate of lymph node BT between the group UTI and I/R (P < 0.05). Histological changes showed that milder damage of intestinal mucosal in group UTI as to group I/R. CONCLUSION: Intestinal ischemia-reperfusion may result in intestinal mucosal damage, the mechanism may be involved in the release of abnormal TNF-alpha, NO, reactive oxygen and activated PMN; UTI can protect intestinal mucosal against intestinal ischemia-reperfusion injury, which may be associated with inhibiting the release of NO and TNF-a, ameliorating reactive oxygen damage, decreasing the aggregation and activation of PMN.

Hybrid-type carbon microcoil-chitosan composite for selective extraction of aristolochic acid I from Aristolochiaceae medicinal plants.

Aristolochic acid I is a nephrotoxic compound widely existing in many kinds of traditional Chinese medicines, especially in Aristolochiaceae medicinal plants. In this study, chitosan modified carbon microcoils were designed and prepared for the selective separation of aristolochic acid I from medicinal herbs. Successful modification of carbon microcoils was confirmed by scanning electron microscopy, Fourier-transfer infrared spectroscopy, elemental analysis, X-ray photoelectron spectroscopy, and thermogravimetric analyses. The effects of adsorption conditions were investigated and it was determined that the adsorption of aristolochic acid I was controlled by pH. Adsorption isotherms, kinetics, and selectivity tests were performed to evaluate the adsorption capacity and selectivity of the modified carbon microcoils. The chitosan modified carbon microcoils exhibited excellent binding ability (77.72 mg g-1) and satisfactory selectivity. Finally, this material was used in solid phase extraction combined with HPLC to enrich and detect aristolochic acid I from medicinal plants. The detector response for aristolochic acid I was linear from 0.5 to 150 mg L-1, and the recoveries of aristolochic acid I ranged from 73.61 to 77.73% with the relative standard deviations of less than 5%. Thus, chitosan modified carbon microcoils were ideal adsorbents for the selective extraction of aristolochic acid I from Aristolochiaceae plants.

[The effect of ligand of peroxisome proliferators-activated receptor gamma 15d-PGJ2 on the proliferation and activation of hepatic stellate cells].

OBJECTIVE: To observe the effect of ligand of peroxisome proliferators-activated receptor gamma (PPAR gamma) 15d-PGJ2 on the proliferation and activation of hepatic stellate cells (HSC) and to study the role played by PPAR gamma during the process of HSC activation. METHODS: By using RT-PCR and cell culture, we investigated the effects of 5 micro mol/L and 10 micro mol/L 15d-PGJ2 on culture-activated HSC and on PDGF-induced HSC proliferation, production of extracellular matrix and expression of chemokines. RESULTS: The expression of alpha-SMA was significantly suppressed by 5mumol/L 15d-PGJ2, and the expression of PPAR gamma was significantly higher in the 15d-PGJ2 treated group than in the untreated group (0.64+/-0.03 vs 0.09+/-0.01, t=36.0517, P<0.01); PDGF-induced HSC proliferation was dose-dependently suppressed by 15d-PGJ2; the expressions of PPAR gamma in 5 micro mol/L and also in 10 micro mol/L 15d-PGJ2 plus PDGF pre-treated group increased much more than those in the PDGF-treated group (0.03+/-0.02 vs 0.60+/-0.03, t=42.6616, P<0.01 and 0.03+/-0.02 vs 0.69+/-0.04, t=33.83, P<0.01); the expressions of alpha-SMA, alpha 1 (I)-collagen and MCP-1 were suppressed. CONCLUSION: Activation of PPAR gamma can modulate pro-fibrotic and pro-inflammatory roles of HSC and the increased expression of PPAR gamma may become a new target for antifibrosis.

Polydopamine/polyethyleneimine complex adhered to micrometer-sized magnetic carbon fibers for high-efficiency hemoperfusion.

Carbon-based nanomaterials have recently attracted tremendous attention in adsorption, separation and biological fields. However, such modification is not always straightforward when the surface is not chemically reactive. Given this reason, most carbon materials modification processes employ reactive linkers or coupling agents, which are complicated and time-consuming. Herein, we report on a dopamine-polyethyleneimine (PEI) coating strategy to fabricate micrometer-sized magnetic carbon fiber (MSMCF)-based extracorporeal blood-cleansing sorbent for hemoperfusion. Results showed that the dopamine/PEI-coated MSMCF had a twisted fiber shape with a size range of 80-120 µm in diameter and porous structure with a specific surface area of 146 m2 g-1. Adsorption behavior of dopamine/PEI-modified MSMCF was examined by using bilirubin as a toxin model compound. Equilibrium data were well fitted to the Langmuir isotherm model with a maximal adsorption capacity of 335.1 mg g-1 at ambient temperature. The as-obtained material had relatively high bilirubin adsorption selectivity against albumin at a normal albumin concentration. In particular, the dopamine/PEI-coated MSMCF has excellent adsorption capacity and hemocompatibility compared to the MSMCF decorated only by dopamine or PEI. Therefore, this work may pave the way for enhancing the property of the extracorporeal blood-cleansing sorbent during hemoperfusion.

ß-Cyclodextrin anchoring onto pericarpium granati-derived magnetic mesoporous carbon for selective capture of lopid in human serum and pharmaceutical wastewater samples.

Functionalized magnetic carbonaceous nanomaterials, which are important materials with many practical and research applications in biomedical, pharmaceutical and biological fields, have recently attracted much attention. In this study, a magnetic mesoporous carbon coated with ß-cyclodextrin (MMC@ß-CD) was synthesized for the first time from natural pericarpium granati (PG). The as-obtained MMC@ß-CD has high surface areas (203 m(2)g(-1)), large pore volumes (0.16 cm(3)g(-1)), relatively broad mesoporous sizes (6.8 nm) and a high saturation magnetization of 26.2 emu g(-1), which is sufficient for magnetic separation by an external magnetic field. The MMC@ß-CD was used as an innovative adsorbent for magnetic solid-phase extraction of lopid via host-guest interaction prior to spectrofluorometric analysis. The proposed method was successfully applied to analyze lopid in human serum and pharmaceutical wastewater samples with recoveries in the range of 85.0-103.5% for the spiked samples. Overall, this work not only provides an inexpensive and eco-friendly method to fabricate MMC@ß-CD (or MMC) from PG, but also develops a highly selective approach for capture of lopid in biological samples and environmental substances.

Two angiotensin-converting enzyme-inhibitory peptides from almond protein and the protective action on vascular endothelial function.

This study aimed to discover and prepare novel angiotensin converting enzyme (ACE) inhibitory peptides from almond protein and further evaluate the effect on endothelial function of human umbilical vascular endothelial cells (HUVECs). Almond protein was hydrolyzed using a two-stage alcalase-protamex hydrolysis process, and the hydrolysates were subjected to a series of separations, ultrafiltration, gel filtration chromatography, and reversed-phased preparative chromatography, to obtain the active peptides. Seven ACE inhibitory fractions with the molecular weight below 1.5 kDa were isolated and prepared, and two purified ACE inhibitory peptides with the IC50 values of 67.52 ± 0.05 and 43.18 ± 0.07 µg mL(-1), were identified as Met-His-Thr-Asp-Asp and Gln-His-Thr-Asp-Asp, respectively. Then the effect of two ACE inhibitory peptides on the endothelial function of HUVECs was evaluated. Results showed that the two potent ACE inhibitory peptides significantly regulated the release of nitric oxide and endothelin in HUVECs. These results suggest that almond peptides have potential as an antihypertensive nutraceuticals or a functional food ingredient.

Effects of phosphodiesterase 4 inhibitor on cough response in guinea pigs sensitized and challenged with ovalbumin.

BACKGROUND: There is currently considerable interest in the potential value of selective inhibitors of cyclic nucleotide phosphodiesterase 4 in the treatment of asthma. However, whether they influence eosinophilic airway inflammation-associated cough remains unclear. The objective of this study was to investigate the effects of selective phosphodiesterase 4 inhibitor SB207499 on cough response and airway inflammation in guinea pigs sensitized and challenged with ovalbumin. METHODS: Forty sensitized guinea pigs were randomly divided into four groups: control (n = 10), challenge (n = 10), SB207499 (n = 10) and aminophylline (n = 10), then challenged with aerosol of 1% ovalbumin or saline. Two hours later, animals were intraperitoneally injected with either saline, 25 mg/kg of SB207499 or aminophylline. At the 24th hour, the injection was repeated with 2.5 mg/kg and 25 mg/kg SB207499 or aminophylline, then cough response to inhaled capsaicin and airway responsiveness to methacholine inducing a 150% of the peak airway pressure to the baseline (PC150) was measured. Finally, total cell number and differentials in bronchoalveolar lavage fluid were analysed. RESULTS: The cough frequency per 3 minutes and PC150 in the challenge group were (22 +/- 4) times/3 minutes and (198 +/- 54) microg/ml, which were significantly different from (6 +/- 2) times/3 minutes and (691 +/- 81) microg/ml in the control group (P < 0.05, respectively). The injection of 25 mg/kg SB207499 significantly inhibited the increased cough response and airway hyperresponsiveness, the cough frequency and PC150 in guinea pigs were (13 +/- 2) times/3 minutes and (680 +/- 81) microg/ml (P < 0.05), which differed significantly from (18 +/- 2) times/3 minutes and (400 +/- 86) microg/ml after the administration of the same dose of aminophylline (P < 0.05). The inhibition of SB207499 on cough response was dose-dependent. Similarly, SB207499 decreased the total cell number and percentage of eosinophils in bronchoalveolar lavage fluid to (2.1 +/- 0.5) x 10(6)/ml and (20 +/- 5)% respectively, which were significantly different from (3.2 +/- 0.5) x 10(6)/ml and (29 +/- 5)% in the aminophylline group (P < 0.05, respectively) or (4.2 +/- 0.7) x 10(6)/ml and (35 +/- 4)% in the challenge group (P < 0.05, respectively). CONCLUSION: Phosphodiesterase 4 inhibitor may be more useful than aminophylline for cough associated with eosinophilic airway inflammation via inhibiting airway inflammation and airway hyperresponsiveness.