Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 17 de 17
Filter
1.
Zhongguo Zhong Yao Za Zhi ; 48(7): 1885-1891, 2023 Apr.
Article in Chinese | MEDLINE | ID: mdl-37282964

ABSTRACT

To study the chemical constituents from the stems and leaves of Humulus scandens, this study isolated thirteen compounds by different chromatographic methods including silica gel column, ODS, Sephadex LH-20 and preparative HPLC. Based on comprehensive analysis, the chemical structures were elucidated and identified as citrunohin A(1), chrysosplenetin(2), casticin(3), neoechinulin A(4), ethyl 1H-indole-3-carboxylate(5), 3-hydroxyacetyl-indole(6),(1H-indol-3-yl) oxoacetamide(7), inonotusic acid(8), arteannuin B(9), xanthotoxol(10), α-tocopherol quinone(11), eicosanyl-trans-p-coumarate(12), and 9-oxo-(10E,12E)-octadecadienoic acid(13). Among them, compound 1 was a new dihydrochalcone, and the other compounds were obtained from H. scandens for the first time.


Subject(s)
Chalcones , Drugs, Chinese Herbal , Humulus , Indoles , Drugs, Chinese Herbal/chemistry
2.
Article in English | MEDLINE | ID: mdl-37143277

ABSTRACT

INTRODUCTION: Cancer is one of the leading causes of death worldwide, accounting for nearly one in six deaths in 2020. As a folk medicine, Xanthium sibiricum Herba (XSH) has been used many times in clinical practice for the treatment of various diseases. With the increasing number of cancer patients, there is a clinical need to find effective anti-cancer drugs. AIM: This study aims to explores the bioactivity and the anti-cancer mechanism of XSH. METHODS: In this study, bioinformatics, network pharmacology, molecular docking, molecular dynamics simulation techniques, and apoptosis assay were used to explore the bioactivity and the anti-cancer mechanism of XSH. RESULTS: Finally, seven active ingredients in XSH after the screening were obtained, the two most active compounds were ß-sitosterol and aloe-emodin, and good anti-cancer activity of XSH was predicted. DISCUSSION: Four core targets were obtained from the PPI network map, namely Caspase-3 (CASP3), Transcription factor AP-1 (JUN), Myc proto-oncogene protein (MYC), and cellular tumor antigen p53 (TP53). GO and KEGG analyses showed that the mechanism of XSH anti-cancer is mainly related to the apoptosis process, and the main signaling pathways are enriched in the p53 signaling pathway, Apoptosis, and MAPK signaling. The molecular docking and molecular dynamics simulation results showed that CASP3, JUN, MYC, and TP53 had a high affinity with ß-sitosterol and aloe-emodin. Bioinformatics analyses demonstrated the importance of core targets. Apoptosis assay showed that XSH could significantly promote the apoptosis of cancer cells, and inhibit their proliferation and migration, especially colon cancer cells. CONCLUSION: This study uncovered the main active components, bioactivities, and potential targets of XSH, and further revealed the multi-component, multi-target, and multi-pathway mechanism of XSH for cancer treatment and promoting apoptosis.

3.
Pharm Biol ; 61(1): 799-814, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37194713

ABSTRACT

CONTEXT: Polygonum hydropiper L. (Polygonaceae) (PH) is a traditional Chinese traditional medicine with a pungent flavor and mild drug properties. PH is mainly distributed in the channel tropism in the stomach and large intestine. PH has multiple uses and can be used to treat a variety of diseases for a long time. OBJECTIVE: This review summarizes the phytochemical and pharmacological activities, and applications of PH from 1980 to 2022. We also provide suggestions for promoting further research and developing additional applications of PH. METHODS: The data and information on PH from 1980 to 2022 reviewed in this article were obtained from scientific databases, including Science Direct, PubMed, Science Citation Index, SciFinder Scholar (SciFinder), Springer, American Chemical Society (ACS) Publications, and China National Knowledge Infrastructure (CNKI), etc. Some information was obtained from classic literature on traditional Chinese medicines. The search terms were Polygonum hydropiper, phytochemistry compositions of Polygonum hydropiper, pharmacological activities of Polygonum hydropiper, and applications of Polygonum hydropiper. RESULTS: The comprehensive analysis of the literature resulted in 324 compounds being isolated, identified, and reported from PH. Regarding traditional uses, the majority of phytochemical and pharmacological studies have indicated the diverse bioactivities of PH extracts, flavonoids, and volatile oil elements, including antibacterial, antifungal, insecticidal, antioxidant, and anti-inflammatory. CONCLUSIONS: PH has a long history of diversified medicinal uses, some of which have been verified in modern pharmacological studies. Further detailed studies are required to establish scientific and reasonable quality evaluation standards and action mechanisms of active constituents from PH.


Subject(s)
Oils, Volatile , Polygonum , Polygonum/chemistry , Medicine, Chinese Traditional , Plant Extracts/pharmacology , Plant Extracts/therapeutic use , Plant Extracts/chemistry , Phytochemicals/pharmacology , Phytochemicals/therapeutic use , Ethnopharmacology
4.
Foods ; 12(5)2023 Mar 02.
Article in English | MEDLINE | ID: mdl-36900584

ABSTRACT

Volatile organic compounds (VOCs) make up milk flavor and are essential attributes for consumers to evaluate milk quality. In order to investigate the influence of heat treatment on the VOCs of milk, electronic nose (E-nose), electronic tongue (E-tongue) and headspace solid-phase microextraction (HS-SPME)-gas chromatography-mass spectrometry (GC-MS) technology were used to evaluate the changes in VOCs in milk during 65 °C heat treatment and 135 °C heat treatment. The E-nose revealed differences in the overall flavor of milk, and the overall flavor performance of milk after heat treatment at 65 °C for 30 min is similar to that of raw milk, which can maximize the preservation of the original taste of milk. However, both were significantly different to the 135 °C-treated milk. The E-tongue results showed that the different processing techniques significantly affected taste presentation. In terms of taste performance, the sweetness of raw milk was more prominent, the saltiness of milk treated at 65 °C was more prominent, and the bitterness of milk treated at 135 °C was more prominent. The results of HS-SPME-GC-MS showed that a total of 43 VOCs were identified in the three types of milk-5 aldehydes, 8 alcohols, 4 ketones, 3 esters, 13 acids, 8 hydrocarbons, 1 nitrogenous compound, and 1 phenol. The amount of acid compounds was dramatically reduced as the heat treatment temperature rose, while ketones, esters, and hydrocarbons were encouraged to accumulate instead. Furfural, 2-heptanone, 2-undecanone, 2-furanmethanol, pentanoic acid ethyl ester, 5-octanolide, and 4,7-dimethyl-undecane can be used as the characteristic VOCs of milk treated at 135 °C. Our study provides new evidence for differences in VOCs produced during milk processing and insights into quality control during milk production.

5.
Article in Chinese | WPRIM | ID: wpr-981407

ABSTRACT

To study the chemical constituents from the stems and leaves of Humulus scandens, this study isolated thirteen compounds by different chromatographic methods including silica gel column, ODS, Sephadex LH-20 and preparative HPLC. Based on comprehensive analysis, the chemical structures were elucidated and identified as citrunohin A(1), chrysosplenetin(2), casticin(3), neoechinulin A(4), ethyl 1H-indole-3-carboxylate(5), 3-hydroxyacetyl-indole(6),(1H-indol-3-yl) oxoacetamide(7), inonotusic acid(8), arteannuin B(9), xanthotoxol(10), α-tocopherol quinone(11), eicosanyl-trans-p-coumarate(12), and 9-oxo-(10E,12E)-octadecadienoic acid(13). Among them, compound 1 was a new dihydrochalcone, and the other compounds were obtained from H. scandens for the first time.


Subject(s)
Humulus , Chalcones , Indoles , Drugs, Chinese Herbal/chemistry
6.
Chemosphere ; 303(Pt 1): 134839, 2022 Sep.
Article in English | MEDLINE | ID: mdl-35537628

ABSTRACT

Since the human consumption of coal is increasingly growing and coal-based solid wastes are discharged in large quantities, the resource utilization of coal-based solid wastes has been paid more attention. In the present work, for the first time, the coal gasification fine slag is subjected to prepare ZSM-5 zeolites with ultra-low n(SiO2)/n(Al2O3) ratios (less than 20) and hierarchical pore structures. The increase in the concentration of the alkaline extract leads to the decrease of the crystallinity, the irregularity of the microscopic morphology, and the decrease of the specific surface area, resulting in the in-situ generation of mesopores within ZSM-5. Moreover, adsorption experiments demonstrate that ZSM-5-2M exhibits the best methylene blue adsorption performance at the pH of 9 with a removal rate of up to 82.07%, and it also has good adsorption performance in simulated real water samples. Furthermore, the adsorption performance of ZSM-5-2M on the malachite green, Rhodamine B, Congo red, and methyl orange has been investigated and it is found to be very effective for the adsorption of cationic dyes, and its adsorption performance for methylene blue and malachite green is reduced in the presence of anions.


Subject(s)
Zeolites , Adsorption , Aluminum Oxide , Coal , Humans , Methylene Blue , Porosity , Silicon Dioxide , Solid Waste , Zeolites/chemistry
7.
Phytomedicine ; 87: 153578, 2021 Jul.
Article in English | MEDLINE | ID: mdl-34038839

ABSTRACT

BACKGROUND: Parkinson's disease (PD) is one of the most common neurodegenerative motor disorders, and is characterized by the presence of Lewy bodies containing misfolded α-synuclein (α-syn) and by selective degeneration of midbrain dopamine neurons. Studies have shown that upregulation of ubiquitin-proteasome system (UPS) activity promotes the clearance of aggregation-prone proteins such as α-syn and Tau, so as to alleviate the neuropathology of neurodegenerative diseases. PURPOSE: To identify and investigate lycorine as a UPS enhancer able to decrease α-syn in transgenic PD models. METHODS: Dot blot was used to screen α-syn-lowering compounds in an inducible α-syn overexpression cell model. Inducible wild-type (WT) and mutant α-syn-overexpressing PC12 cells, WT α-syn-overexpressing N2a cells and primary cultured neurons from A53T transgenic mice were used to evaluate the effects of lycorine on α-syn degradation in vitro. Heterozygous A53T transgenic mice were used to evaluate the effects of lycorine on α-syn degradation in vivo. mCherry-GFP-LC3 reporter was used to detect autophagy-dependent degradation. Ub-R-GFP and Ub-G76V-GFP reporters were used to detect UPS-dependent degradation. Proteasome activity was detected by fluorogenic substrate Suc-Leu-Leu-Val-Tyr-AMC (Suc-LLVY-AMC). RESULTS: Lycorine significantly promoted clearance of over-expressed WT and mutant α-syn in neuronal cell lines and primary cultured neurons. More importantly, 15 days' intraperitoneal administration of lycorine effectively promoted the degradation of α-syn in the brains of A53T transgenic mice. Mechanistically, lycorine accelerated α-syn degradation by activating cAMP-dependent protein kinase (PKA) to promote proteasome activity. CONCLUSION: Lycorine is a novel α-syn-lowering compound that works through PKA-mediated UPS activation. This ability to lower α-syn implies that lycorine has the potential to be developed as a pharmaceutical for the treatment of neurodegenerative diseases, such as PD, associated with UPS impairment and protein aggregations.


Subject(s)
Amaryllidaceae Alkaloids/pharmacology , Cyclic AMP-Dependent Protein Kinases/metabolism , Parkinson Disease/drug therapy , Phenanthridines/pharmacology , alpha-Synuclein/metabolism , Animals , Autophagy/drug effects , Autophagy/physiology , Cyclic AMP/metabolism , Disease Models, Animal , Humans , Male , Mice, Transgenic , Neuroprotective Agents/pharmacology , PC12 Cells , Parkinson Disease/metabolism , Parkinson Disease/pathology , Proteasome Endopeptidase Complex/metabolism , Rats , Ubiquitin/metabolism , Up-Regulation/drug effects , alpha-Synuclein/genetics
8.
Zhongguo Zhong Yao Za Zhi ; 46(10): 2501-2508, 2021 May.
Article in Chinese | MEDLINE | ID: mdl-34047096

ABSTRACT

In this paper, the extraction rate of crude polysaccharides and the yield of polysaccharides from Hippocampus served as test indicators. The comprehensive evaluation indicators were assigned by the R language combined with the entropy weight method. The Box-Behnken design-response surface methodology(BBD-RSM) and the deep neural network(DNN) were employed to screen the optimal parameters for the polysaccharide extraction from Hippocampus. These two modeling methods were compared and verified experimentally for the process optimization. This study provides a reference for the industrialization of effective component extraction from Chinese medicinals and achieves the effective combination of modern technology and traditional Chinese medicine.


Subject(s)
Dietary Carbohydrates , Polysaccharides , Hippocampus , Neural Networks, Computer , Temperature
9.
Article in Chinese | WPRIM | ID: wpr-879153

ABSTRACT

In this paper, the extraction rate of crude polysaccharides and the yield of polysaccharides from Hippocampus served as test indicators. The comprehensive evaluation indicators were assigned by the R language combined with the entropy weight method. The Box-Behnken design-response surface methodology(BBD-RSM) and the deep neural network(DNN) were employed to screen the optimal parameters for the polysaccharide extraction from Hippocampus. These two modeling methods were compared and verified experimentally for the process optimization. This study provides a reference for the industrialization of effective component extraction from Chinese medicinals and achieves the effective combination of modern technology and traditional Chinese medicine.


Subject(s)
Dietary Carbohydrates , Hippocampus , Neural Networks, Computer , Polysaccharides , Temperature
10.
Mater Sci Eng C Mater Biol Appl ; 108: 110512, 2020 Mar.
Article in English | MEDLINE | ID: mdl-31924017

ABSTRACT

980-nm-upconverted 530 and 550 nm Er3+ green fluorescence spectra of Er3+/Yb3+-codoped NaGd(WO4)2 submicron crystals were measured in the temperature range of 298-383 K. A sextuple ratiometric thermometry is proposed. It is established on the basis of six schemes of fluorescence intensity ratio (FIR) that considers three component peaks of the 530 nm emission band and two component peaks of the 550 nm emission band, which involve electronic transitions between two Stark sublevels of Er3+. The study shows that the phosphor shows strong green fluorescence, which is verified by measured quantum yield, and thermally stable spectral structure desired for the sextuple ratiometric thermometry. All of the six FIR schemes display highly efficient sensing performances with slightly different thermal sensitivities. Each scheme gives a temperature value and the six schemes give an averaged result. In parallel, we have also carried out an ex vivo experimental study on the temperature characteristics of the green fluorescence of the phosphor. Almost same results have been obtained, verifying biological applicability of the phosphor. The ex vivo experimental results also show that the sextuple thermometry increases considerably the accuracy and reliability of temperature measurement in comparison with the conventional intensity integration method.


Subject(s)
Erbium/chemistry , Fluorescence , Phosphorus/chemistry , Thermometry/methods , Hot Temperature , Luminescence , Microscopy, Electron, Scanning , Nanoparticles/chemistry , Nitrates , Reproducibility of Results , Scattering, Radiation , X-Ray Diffraction , Ytterbium/chemistry
11.
Article in Chinese | WPRIM | ID: wpr-824969

ABSTRACT

Objective: To evaluate the efficacy and safety of acupuncture for the treatment of knee osteoarthritis and to provide evidence for its use in clinical practice. Methods: Eight databases were extensively searched up to March 2018. Randomized controlled trials (RCTs) comparing the efficacy of acupuncture with sham acupuncture or no acupuncture for knee osteoarthritis were included. Study selection, data extraction and quality assessment were independently conducted by two reviewers. The Cochrane Collaboration's tool was used for assessing the risk of bias. Results: A total of 18 RCTs were included, involving a total of 3522 participants. The results showed that acupuncture was superior to sham acupuncture in relieving pain (SMD=-0.34, 95%CI:-0.57 to -0.11, I2=85%, P=0.003) and improving physical function (SMD=-0.34, 95%CI: -0.57 to -0.11, I2=85%, P=0.003). In comparison to the no-acupuncture group, the acupuncture group also showed significant advantages in relieving pain (SMD=-0.79, 95%CI: -1.15 to -0.43, I2=87%, P<0.0001) and improving physical function (SMD=-0.75, 95%CI:-1.19 to -0.31, I2=91%, P=0.0008). Sensitivity analyses suggested that the results were robust, and Egger's test found no potential publication bias. Conclusion: In the treatment of knee osteoarthritis, the acupuncture group had significant advantages over sham acupuncture or no-acupuncture groups in relieving pain and improving physical function.

12.
BMC Complement Altern Med ; 19(1): 109, 2019 May 23.
Article in English | MEDLINE | ID: mdl-31122236

ABSTRACT

BACKGROUND: Berberine is an isoquinoline alkaloid extracted from various Berberis species which is widely used in East Asia for a wide range of symptoms. Recently, neuroprotective effects of berberine in Alzheimer's disease (AD) animal models are being extensively reported. So far, no clinical trial has been carried out on the neuroprotective effects of berberine. However, a review of the experimental data is needed before choosing berberine as a candidate drug for clinical experiments. We conducted a systematic review on AD rodent models to analyze the drug effects with minimal selection bias. METHODS: Five online literature databases were searched to find publications reporting studies of the effect of berberine treatment on animal models of AD. Up to March 2018, 15 papers were identified to describe the efficacy of berberine. RESULTS: The included 15 articles met our inclusion criteria with different quality ranging from 3 to 5. We analyzed data extracted from full texts with regard to pharmacological effects and potential anti-Alzheimer's properties. Our analysis revealed that in multiple memory defects animal models, berberine showed significant memory-improving activities with multiple mechanisms, such as anti-inflammation, anti-oxidative stress, cholinesterase (ChE) inhibition and anti-amyloid effects. CONCLUSION: AD is likely to be a complex disease driven by multiple factors. Yet, many therapeutic strategies based on lowering ß-amyloid have failed in clinical trials. This suggest that the threapy should not base on a single cause of Alzheimer's disease but rather a number of different pathways that lead to the disease. Overall we think that berberine can be a promising multipotent agent to combat Alzheimer's disease.


Subject(s)
Alzheimer Disease , Berberine , Neuroprotective Agents , Alzheimer Disease/drug therapy , Alzheimer Disease/metabolism , Alzheimer Disease/physiopathology , Animals , Berberine/chemistry , Berberine/pharmacology , Berberine/therapeutic use , Disease Models, Animal , Mice , Neuroprotective Agents/chemistry , Neuroprotective Agents/pharmacology , Neuroprotective Agents/therapeutic use , Rats
13.
Phytomedicine ; 61: 152842, 2019 Aug.
Article in English | MEDLINE | ID: mdl-31048127

ABSTRACT

BACKGROUND: Parkinson's disease (PD) is an age-dependent progressive movement disorder characterized by a profound and selective loss of nigrostriatal dopaminergic neurons. Accumulation of -synuclein (-syn) positive protein aggregates in the substantia nigra is a pathological hallmark of PD, indicating that protein turnover defect is implicated in PD pathogenesis. PURPOSE: This study aims to identify neuroprotective compounds which can alleviate the accumulation of -syn in neuronal cells and dissect the underlying mechanisms. METHODS: High throughput screening was performed by dot blot assay. The degradation of different forms of -syn by candidate compounds were assessed by western blot. The autophagy lysosome pathway and ubiquitin-proteasome system were examined to dissect the degradation pathway. The UPS activity was assessed by cellular UPS substrates degradation assay and biochemical proteasome activity assay. Q-PCR was performed to test the mRNA level of different proteasome subunits. Furthermore, Neuroprotective effect of candidate compound was tested by LDH assay and PI staining. RESULTS: Through the high throughput screening, harmine was identified as a potent -syn lowering compound. The time-dependent and dose-dependent effects of harmine on the degradation of different forms of -syn were further confirmed. Harmine could dramatically promote the degradation of UPS substrates GFP-CL1, Ub-R-GFP and Ub-G76V-GFP, and activate cellular proteasome activity. Mechanistically, harmine dramatically enhanced PKA phosphorylation to enhance proteasome subunit PSMD1 expression. PKA inhibitor blocked the effects of harmine in activating UPS, up regulating PSMD1 and promoting -syn degradation, indicating that harmine enhances UPS function via PKA activation. Moreover, harmine efficiently rescued cell death induced by over-expression of -syn, via UPS-dependent manner. CONCLUSION: Harmine, as a new proteasome enhancer, may have potential to be developed into therapeutic agent against neurodegenerative diseases associated with UPS dysfunction and aberrant proteins accumulation.


Subject(s)
Harmine/pharmacology , Neurons/drug effects , Proteasome Endopeptidase Complex/metabolism , Ubiquitin/metabolism , alpha-Synuclein/metabolism , Animals , Autophagy/drug effects , Cells, Cultured , Cyclic AMP-Dependent Protein Kinases/metabolism , Female , Mice, Transgenic , Neurons/metabolism , PC12 Cells , Phosphorylation/drug effects , Rats , alpha-Synuclein/genetics
14.
Public Health Nutr ; 18(8): 1514-21, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25323814

ABSTRACT

OBJECTIVE: Folate and vitamin B12 are two vital regulators in the metabolic process of homocysteine, which is a risk factor of atherothrombotic events. Low folate intake or low plasma folate concentration is associated with increased stroke risk. Previous randomized controlled trials presented discordant findings in the effect of folic acid supplementation-based homocysteine lowering on stroke risk. The aim of the present review was to perform a meta-analysis of relevant randomized controlled trials to check the how different folate fortification status might affect the effects of folic acid supplementation in lowering homocysteine and reducing stroke risk. DESIGN: Relevant randomized controlled trials were identified through formal literature search. Homocysteine reduction was compared in subgroups stratified by folate fortification status. Relative risks with 95 % confidence intervals were used as a measure to assess the association between folic acid supplementation and stroke risk. SETTING: The meta-analysis included fourteen randomized controlled trials, SUBJECTS: A total of 39 420 patients. RESULTS: Homocysteine reductions were 26·99 (sd 1·91) %, 18·38 (sd 3·82) % and 21·30 (sd 1·98) %, respectively, in the subgroups without folate fortification, with folate fortification and with partial folate fortification. Significant difference was observed between the subgroups with folate fortification and without folate fortification (P=0·05). The relative risk of stroke was 0·88 (95 % CI 0·77, 1·00, P=0·05) in the subgroup without folate fortification, 0·94 (95 % CI 0·58, 1·54, P=0·82) in the subgroup with folate fortification and 0·91 (95 % CI 0·82, 1·01, P=0·09) in the subgroup with partial folate fortification. CONCLUSIONS: Folic acid supplementation might have a modest benefit on stroke prevention in regions without folate fortification.


Subject(s)
Folic Acid/blood , Food, Fortified , Homocysteine/blood , Stroke/epidemiology , Databases, Factual , Folic Acid/administration & dosage , Humans , Randomized Controlled Trials as Topic , Risk Factors , Stroke/blood , Stroke/prevention & control , Vitamin B 12/administration & dosage , Vitamin B 12/blood
15.
Zhong Yao Cai ; 32(7): 1065-6, 2009 Jul.
Article in Chinese | MEDLINE | ID: mdl-19873734

ABSTRACT

OBJECTIVE: To study the chemical constituents of Blumea laciniata. METHODS: The chemical constituents of the ethyl acetate fraction of ethanol extract from Blumea laciniata were isolated with column chromatographic techniques. The structures of the isolated compounds were elucidated by spectroscopic analysis and comparison with their published datas. RESULTS: Five compounds were isolated and identified as: protocatechuic acid (1), chrysoeriol (2), apigenin (3), 4-hydroxy-3,5-dimethoxbenzoic acid (4), scopolet (5). CONCLUSION: Compounds 1 - 5 are isolated from this plant for the first time, and also obtained from this genus for the first time.


Subject(s)
Asteraceae/chemistry , Flavonoids/isolation & purification , Hydroxybenzoates/isolation & purification , Plants, Medicinal/chemistry , Apigenin/chemistry , Apigenin/isolation & purification , Flavones , Flavonoids/chemistry , Hydroxybenzoates/chemistry , Magnetic Resonance Spectroscopy , Molecular Structure , Scopoletin/chemistry , Scopoletin/isolation & purification , Spectrophotometry, Ultraviolet
16.
J Biol Chem ; 281(11): 7205-13, 2006 Mar 17.
Article in English | MEDLINE | ID: mdl-16410241

ABSTRACT

Receptor activity-modifying proteins (RAMPs) enable calcitonin receptor-like receptor (CRLR) to function as a calcitonin gene-related peptide receptor (CRLR/RAMP1) or an adrenomedullin (AM) receptor (CRLR/RAMP2 or -3). Here we investigated the functions of the cytoplasmic C-terminal tails (C-tails) of human RAMP1, -2, and -3 (hRAMP1, -2, and -3) by cotransfecting their C-terminal deletion or progressive truncation mutants into HEK-293 cells stably expressing hCRLR. Deletion of the C-tail from hRAMP1 had little effect on the surface expression, function, or intracellular trafficking of the mutant heterodimers. By contrast, deletion of the C-tail from hRAMP2 disrupted transport of hCRLR to the cell surface, resulting in significant reductions in (125)I-hAM binding and evoked cAMP accumulation. The transfection efficiency for the hRAMP2 mutant was comparable with that for wild-type hRAMP2; moreover, immunocytochemical analysis showed that the mutant hRAMP2 remained within the endoplasmic reticulum. FACS analysis revealed that deleting the C-tail from hRAMP3 markedly enhances AM-evoked internalization of the mutant heterodimers, although there was no change in agonist affinity. Truncating the C-tails by removing the six C-terminal amino acids of hRAMP2 and -3 or exchanging their C-tails with one another had no effect on surface expression, agonist affinity, or internalization of hCRLR, which suggests that the highly conserved Ser-Lys sequence within hRAMP C-tails is involved in cellular trafficking of the two AM receptors. Notably, deleting the respective C-tails from hRAMPs had no effect on lysosomal sorting of hCRLR. Thus, the respective C-tails of hRAMP2 and -3 differentially affect hCRLR surface delivery and internalization.


Subject(s)
Calcitonin Gene-Related Peptide/chemistry , Cytoplasm/metabolism , Receptors, Peptide/chemistry , Amino Acid Sequence , Blotting, Western , Cell Line , Cell Membrane/metabolism , Cell Proliferation , Cell Separation , Cyclic AMP/metabolism , Cycloheximide/pharmacology , DNA/chemistry , DNA, Complementary/metabolism , Dimerization , Dose-Response Relationship, Drug , Endoplasmic Reticulum/metabolism , Flow Cytometry , Gene Deletion , Green Fluorescent Proteins/chemistry , Humans , Immunohistochemistry , Intracellular Signaling Peptides and Proteins/chemistry , Intracellular Signaling Peptides and Proteins/metabolism , Lysine/chemistry , Lysosomes/chemistry , Lysosomes/metabolism , Membrane Proteins/chemistry , Membrane Proteins/metabolism , Microscopy, Fluorescence , Molecular Sequence Data , Mutation , Protein Binding , Protein Structure, Tertiary , RNA, Messenger/metabolism , Receptor Activity-Modifying Protein 1 , Receptor Activity-Modifying Protein 2 , Receptor Activity-Modifying Proteins , Receptors, Adrenomedullin , Recombinant Fusion Proteins/chemistry , Serine/chemistry , Time Factors , Transfection
17.
Se Pu ; 24(6): 636-40, 2006 Nov.
Article in Chinese | MEDLINE | ID: mdl-17288151

ABSTRACT

The issue of residues including organochlorine and pyrethroid pesticides in tea has made a great attention of researchers and customers in the world. Although some analytical methods have well been established to detect these pesticides, the sample preparations are generally laborious, time-consuming, and some of the procedures caused environmental pollution. Solid phase microextraction (SPME) is a novel sample preparation technique since it is of simplicity, high efficiency and solvent free. SPME was firstly developed to address the need to facilitate environment monitoring. In recent years, great efforts have been made in the analysis of pesticide residues in agricultural products by SPME. In this research, a microwave assisted extraction solid phase microextraction-gas chromatography (MAE-SPME-GC) was applied for the simultaneous determination of organochlorine and pyrethroid pesticides, such as benzene hexa chlorides (alpha-BHC, beta-BHC, gamma-BHC and delta-BHC), 1-(2-chlorophenyl)-1-(4-chlorophenyl)-2, 2, 2-trichloroethane (o, p'-DDT), 2, 2-bis (4-chlorophenyl)-1, 1-dichloroethylene (DDE), 2, 2-bis (4-chlorophenyl)-1, 1-dichloroethane (DDD), 2-(2-chlorophenyl)-2-(4-chlorophenyl)-1, 1, 1-trichloroethane (p, p'-DDT), cypermethrin and fenvalerate. All the tested pesticides were baseline separated under the experimental conditions, except for DDD and o, p'-DDT. The concentration of each pesticide was calibrated by external standard method. The linearities were found to be in the correlation coefficient range of 0.970 5 to 0.998 4 for the tested pesticides between the mass concentrations and peak areas, except for fenvalerate. The recoveries, relative standard deviations and detection limits for the 10 pesticides were 64% - 121%, 10.4% -22.9%, and 1 - 50 ng/L, respectively. The proposed method was successfully applied to the determination of organochlorine pesticide residues in three kinds of teas from the local market. The experimental results demonstrated that MAE-SPME-GC was a fast, sensitive and green technique for the analysis of trace quantity of pesticides in solid substrate foods.


Subject(s)
Hydrocarbons, Chlorinated/analysis , Pesticide Residues/analysis , Pyrethrins/analysis , Tea/chemistry , Chromatography, Gas , Microwaves , Solid Phase Microextraction
SELECTION OF CITATIONS
SEARCH DETAIL