Base de dados : MEDLINE
Pesquisa : B01.650.940.800.575.912.250.100.100.144 [Categoria DeCS]
Referências encontradas : 437 [refinar]
Mostrando: 1 .. 10   no formato [Longo]

página 1 de 44 ir para página                         

  1 / 437 MEDLINE  
              next record last record
seleciona
para imprimir
Fotocópia
Texto completo
PMID:29317241
Autor:Wojtkowiak-Giera A; Derda M; Kosik-Bogacka D; Kolasa-Wolosiuk A; Solarczyk P; Cholewinski M; Wandurska-Nowak E; Jagodzinski PP; Hadas E
Endereço:Department of Biology and Medical Parasitology, Poznan University of Medical Sciences, 10 Fredry Street, 61-701 Poznan, Poland.
Título:Influence of Artemisia annua L. on toll-like receptor expression in brain of mice infected with Acanthamoeba sp.
Fonte:Exp Parasitol; 185:17-22, 2018 Feb.
ISSN:1090-2449
País de publicação:United States
Idioma:eng
Resumo:The treatment of acanthamoebiasis is a still a problem. Our previous studies showed that the application of extracts from Artemisia annua L. significantly prolonged the survival of mice infected by Acanthamoeba. This plant has medicinal properties in the treatment of human parasitic diseases. The aim of this study was to evaluate the effects of A. annua on expression of Toll-like receptors (TLRs) 2 and 4 in brain of mice with Acanthamoeba infection. Mice were infected with Acanthamoeba sp. strain Ac309 (KY203908) by intranasal inoculation without and after application of A. annua extract. The administration of extract from A. annua significantly reduced the level of expression of TLR2 and modified the level of expression of TLR4. A. annua extract is a natural substance that is well tolerated in animals and may be considered as a combination therapy in treatment of acanthamoebiasis. Our study suggested that A. annua extract may be used as an alternative therapeutic tool.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Plant Extracts); 0 (RNA, Messenger); 0 (Tlr2 protein, mouse); 0 (Tlr4 protein, mouse); 0 (Toll-Like Receptor 2); 0 (Toll-Like Receptor 4); 0 (Toll-Like Receptors)


  2 / 437 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
PMID:27773251
Autor:Chemat S; Aissa A; Boumechhour A; Arous O; Ait-Amar H
Endereço:Extraction & Separation Techniques Team, Centre de Recherches Scientifique et Technique en Analyses Physico-Chimiques (C.R.A.P.C.), BP 248 Alger RP 16004, Algiers, Algeria. Electronic address: chemats@yahoo.fr.
Título:Extraction mechanism of ultrasound assisted extraction and its effect on higher yielding and purity of artemisinin crystals from Artemisia annua L. leaves.
Fonte:Ultrason Sonochem; 34:310-316, 2017 01.
ISSN:1873-2828
País de publicação:Netherlands
Idioma:eng
Resumo:This study proposes an ultrasound-horn system for the extraction of a natural active compound "artemisinin" from Artemisia annua L. leaves as an alternative to hot maceration technique. Ultrasound leaching improves artemisinin recovery at all temperatures where only ten minutes is required to recover 70% (4.42mgg ) compared to 60min of conventional hot leaching for the same yield. For instance, ultrasound treatment at 30°C produced a higher yield than the one obtained by conventional maceration at 40°C. Kinetic study suggests that the extraction pattern can be assimilated, during the first ten minutes, to a first order steady state, from which activation energy calculations revealed that each gram of artemisinin required 7.38kJ in ultrasound versus 10.3kJ in the conventional system. Modeling results indicate the presence of two extraction stages, a faster stage with a diffusion coefficient of 19×10 cm min for ultrasound technique at 40°C, seven times higher than the conventional one; and a second deceleration stage similar for both techniques with diffusion coefficient ranging from 1.7 to 3.1×10 cm min . It is noted that the efficient ultrasound extraction potential implies extraction of higher amount of co-metabolites so low artemisinin crystal purity is engendered but a combination with a purification step using activated charcoal and celite adsorbents produced crystals with comparable purity for conventional and ultrasound samples.
Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
Nome de substância:0 (Artemisinins); 9RMU91N5K2 (artemisinine)


  3 / 437 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
PMID:28880869
Autor:Zhang X; Zhao Y; Guo L; Qiu Z; Huang L; Qu X
Endereço:College of Pharmacy, Changchun University of Chinese Medicine, Changchun, Jilin, China.
Título:Differences in chemical constituents of Artemisia annua L from different geographical regions in China.
Fonte:PLoS One; 12(9):e0183047, 2017.
ISSN:1932-6203
País de publicação:United States
Idioma:eng
Resumo:BACKGROUND: Daodi-herb is a part of Chinese culture, which has been naturally selected by traditional Chinese medicine clinical practice for many years. Sweet wormwood herb is a kind of Daodi-herb, and comes from Artemisia annua L. Artemisinin is a kind of effective antimalarial drug being extracted from A. annua. Because of artemisinin, Sweet wormwood herb earns a reputation. Based on the Pharmacopoeia of the People's Republic of China (PPRC), Sweet wormwood herb can be used to resolve summerheat-heat, and prevent malaria. Besides, it also has other medical efficacies. A. annua, a medicinal plant that is widely distributed in the world contains many kinds of chemical composition. Research has shown that compatibility of artemisinin, scopoletin, arteannuin B and arteannuic acid has antimalarial effect. Compatibility of scopoletin, arteannuin B and arteannuic acid is conducive to resolving summerheat-heat. Chemical constituents in A. annua vary significantly according to geographical locations. So, distribution of A. annua may play a key role in the characteristics of efficacy and chemical constituents of Sweet wormwood herb. It is of great significance to study this relationship. OBJECTIVES: We mainly analyzed the relationship between the chemical constituents (arteannuin B, artemisinin, artemisinic acid, and scopoletin) with special efficacy in A. annua that come from different provinces in china, and analyzed the relationship between chemical constituents and spatial distribution, in order to find out the relationship between efficacy, chemical constituents and distribution. METHODS: A field survey was carried out to collect A. annua plant samples. A global positioning system (GPS) was used for obtaining geographical coordinates of sampling sites. Chemical constituents in A. annua were determined by liquid chromatography tandem an atmospheric pressure ionization-electrospray mass spectrometry. Relationship between chemical constituents including proportions, correlation analysis (CoA), principal component analysis (PCA) and cluster analysis (ClA) was displayed through Excel and R software version2.3.2(R), while the one between efficacy, chemical constituents and spatial distribution was presented through ArcGIS10.0, Excel and R software. RESULTS: According to the results of CoA, arteannuin B content presented a strong positive correlation with artemisinic acid content (p = 0), and a strong negative correlation with artemisinin content (p = 0). Scopoletin content presented a strong positive correlation with artemisinin content (p = 0), and a strong negative correlation with artemisinic acid content (p = 0). According to the results of PCA, the first two principal components accounted for 81.57% of the total accumulation contribution rate. The contribution of the first principal component is about 45.12%, manly including arteannuin B and artemisinic acid. The contribution of the second principal component is 36.45% of the total, manly including artemisinin and scopoletin. According to the ClA by using the principal component scores, 19 provinces could be divided into two groups. In terms of provinces in group one, the proportions of artemisinin are all higher than 80%. Based on the results of PCA, ClA, percentages and scatter plot analysis, chemical types are defined as "QHYS type", "INT type" and "QHS type." CONCLUSION: As a conclusion, this paper shows the relationship between efficacy, chemical constituents and distribution. Sweet wormwood herb with high arteannuin B and artemisinic acid content, mainly distributes in northern China. Sweet wormwood herb with high artemisinin and scopoletin content has the medical function of preventing malaria, which mainly distributes in southern China. In this paper, it is proved that Sweet wormwood Daodi herb growing in particular geographic regions, has more significant therapeutical effect and higher chemical constituents compared with other same kind of CMM. And also, it has proved the old saying in China that Sweet wormwood Daodi herb which has been used to resolve summerheat-heat and prevent malaria, which distributed in central China. But in modern time, Daodi Sweet wormwood herb mainly has been used to extract artemisinin and prevent malaria, so the Daod-region has transferred to the southern China.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Antimalarials); 0 (Artemisinins); 0 (Plant Extracts); 50906-56-4 (arteannuin B); 53N99527G7 (artemisic acid); 9RMU91N5K2 (artemisinine); KLF1HS0SXJ (Scopoletin)


  4 / 437 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
PMID:28566563
Autor:Liu S; Ferreira JFDS; Liu L; Tang Y; Tian D; Liu Z; Tian N
Endereço:Department of Tea Science, College of Horticulture and Hardening, Hunan Agricultural University.
Título:Isolation of Dihydroartemisinic Acid from Artemisia annua L. By-Product by Combining Ultrasound-Assisted Extraction with Response Surface Methodology.
Fonte:Chem Pharm Bull (Tokyo); 65(8):746-753, 2017 Aug 01.
ISSN:1347-5223
País de publicação:Japan
Idioma:eng
Resumo:Malaria is the most devastating parasitic disease worldwide. Artemisinin is the only drug that can cure malaria that is resistant to quinine-derived drugs. After the commercial extraction of artemisinin from Artemisia annua, the recovery of dihydroartemisinic acid (DHAA) from artemisinin extraction by-product has the potential to increase artemisinin commercial yield. Here we describe the development and optimization of an ultrasound-assisted alkaline procedure for the extraction of DHAA from artemisinin production waste using response surface methodology. Our results using this methodology established that NaOH at 0.36%, extraction time of 67.96 min, liquid-solid ratio of 5.89, and ultrasonic power of 83.9 W were the optimal conditions to extract DHAA from artemisinin production waste. Under these optimal conditions, we achieved a DHAA yield of 2.7%. Finally, we conducted a validation experiment, and the results confirmed the prediction generated by the regression model developed in this study. This work provides a novel way to increase the production of artemisinin per cultivated area and to reduce artemisinin production costs by recycling its commercial waste to obtain DHAA, an immediate precursor of artemisinin. The use of this technology may reduce the costs of artemisinin-based antimalarial medicines.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Artemisinins); 0 (dihydroartemisinic acid); 55X04QC32I (Sodium Hydroxide)


  5 / 437 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
PMID:28526743
Autor:Fang X; Li JX; Huang JQ; Xiao YL; Zhang P; Chen XY
Endereço:State Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China.
Título:Systematic identification of functional residues of amorpha-4,11-diene synthase.
Fonte:Biochem J; 474(13):2191-2202, 2017 Jun 16.
ISSN:1470-8728
País de publicação:England
Idioma:eng
Resumo:Terpene synthases (TPSs) are responsible for the extremely diversified and complex structure of terpenoids. Amorpha-4,11-diene synthase (ADS) has a high (90%) fidelity in generating the sesquiterpene precursor for the biosynthesis of artemisinin, an antimalarial drug, however, little is known about how active site residues of ADS are involved in carbocation rearrangement and cyclization reactions. Here, we identify seven residues that are key to most of the catalytic steps in ADS. By structural modeling and amino acid sequence alignments of ADS with two functionally relevant sesquiterpene synthases from , we performed site-directed mutagenesis and found that a single substitution, T296V, impaired the ring closure activity almost completely, and tetra-substitutions (L374Y/L404V/L405I/G439S) led to an enzyme generating 80% monocyclic bisabolyl-type sesquiterpenes, whereas a double mutant (T399L/T447G) showed compromised activity in regioselective deprotonation to yield 34.7 and 37.7% normal and aberrant deprotonation products, respectively. Notably, Thr296, Leu374, Gly439, Thr399, and Thr447, which play a major role in directing catalytic cascades, are located around conserved metal-binding motifs and function through impacting the folding of the substrate/intermediate, implying that residues surrounding the two motifs could be valuable targets for engineering TPS activity. Using this knowledge, we substantially increased amorpha-4,11-diene production in a near-additive manner by engineering Thr399 and Thr447 for product release. Our results provide new insight for the rational design of enzyme activity using synthetic biology.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Sesquiterpenes); 0 (amorpha-4,11-diene); EC 2.5.- (Alkyl and Aryl Transferases); EC 2.5.1.- (amorpha-4,11-diene synthase); EC 2.5.1.- (terpene synthase)


  6 / 437 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
PMID:28477002
Autor:Xia QH; Zheng LP; Zhao PF; Wang JW
Endereço:College of Pharmaceutical Sciences, Soochow University, Suzhou 215123, People's Republic of China.
Título:Biosynthesis of silver nanoparticles using callus for inhibiting stem-end bacteria in cut carnation flowers.
Fonte:IET Nanobiotechnol; 11(2):185-192, 2017 Mar.
ISSN:1751-8741
País de publicação:England
Idioma:eng
Resumo:A biological method for synthesising silver nanoparticles (AgNPs) was developed using the callus extracts from L. under sunlight at 25,000 lx. The AgNPs were characterised using transmission electron microscopy, atomic force microscope, X-ray diffraction and Fourier transform infrared spectroscopy. The AgNPs were mostly spherical with the size of 2.1 to 45.2 nm (average 10.9 nm). Pulse treatments of AgNPs at 125, 250 and 500 mg/l for 1 h extended vase life of cut carnation ( cv. Green Land) flowers. Four dominant bacteria strains sp., and were isolated from the stem-ends of cut flowers. AgNP pulse inhibited significantly bacterial growth in vase solution and cut stem ends during all of the vase period. The bacteria related blockage in the stem-ends was significantly alleviated by AgNP pulse because of its higher antibacterial efficacy against the dominant bacteria. In addition, ethylene release of cut carnation flowers was inhibited in response to AgNP pulse. This is the first time that the biologically synthesised AgNPs could be applied as a promising preservative agent for cut carnation flowers.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Anti-Bacterial Agents); 0 (Plant Extracts); 3M4G523W1G (Silver)


  7 / 437 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo SciELO Brasil
PMID:28327802
Autor:Mesa LE; Vasquez D; Lutgen P; Vélez ID; Restrepo AM; Ortiz I; Robledo SM
Endereço:Programa de Estudio y Control de Enfermedades Tropicales-PECET, Instituto de Investigaciones Médicas, Facultad de Medicina, Universidad de Antioquia, Medellín, Colombia.
Título:In vitro and in vivo antileishmanial activity of Artemisia annua L. leaf powder and its potential usefulness in the treatment of uncomplicated cutaneous leishmaniasis in humans.
Fonte:Rev Soc Bras Med Trop; 50(1):52-60, 2017 Jan-Feb.
ISSN:1678-9849
País de publicação:Brazil
Idioma:eng
Resumo:INTRODUCTION:: Cutaneous leishmaniasis (CL) is a tropical disease that affects millions of individuals worldwide. The current drugs for CL may be effective but have serious side effects; hence, alternatives are urgently needed. Although plant-derived materials are used for the treatment of various diseases in 80% of the global population, the validation of these products is essential. Gelatin capsules containing dried Artemisia annua leaf powder were recently developed as a new herbal formulation (totum) for the oral treatment of malaria and other parasitic diseases. Here, we aimed to determine the usefulness of A. annua gel capsules in CL. METHODS:: The antileishmanial activity and cytotoxicity of A. annua L. capsules was determined via in vitro and in vivo studies. Moreover, a preliminary evaluation of its therapeutic potential as antileishmanial treatment in humans was conducted in 2 patients with uncomplicated CL. RESULTS:: Artemisia annua capsules showed moderate in vitro activity in amastigotes of Leishmania (Viannia) panamensis; no cytotoxicity in U-937 macrophages or genotoxicity in human lymphocytes was observed. Five of 6 (83.3%) hamsters treated with A. annua capsules (500mg/kg/day) for 30 days were cured, and the 2 examined patients were cured 45 days after initiation of treatment with 30g of A. annua capsules, without any adverse reactions. Both patients remained disease-free 26 and 24 months after treatment completion. CONCLUSION:: Capsules of A. annua L. represent an effective treatment for uncomplicated CL, although further randomized controlled trials are needed to validate its efficacy and safety.
Tipo de publicação: CASE REPORTS; JOURNAL ARTICLE
Nome de substância:0 (Antiprotozoal Agents); 0 (Plant Extracts)


  8 / 437 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
PMID:28207974
Autor:Matías-Hernández L; Jiang W; Yang K; Tang K; Brodelius PE; Pelaz S
Endereço:Centre for Research in Agricultural Genomics, CSIC-IRTA-UAB-UB, Campus UAB, Bellaterra (Cerdanyola del Vallès), 08193, Barcelona, Spain.
Título:AaMYB1 and its orthologue AtMYB61 affect terpene metabolism and trichome development in Artemisia annua and Arabidopsis thaliana.
Fonte:Plant J; 90(3):520-534, 2017 May.
ISSN:1365-313X
País de publicação:England
Idioma:eng
Resumo:The effective anti-malarial drug artemisinin (AN) isolated from Artemisia annua is relatively expensive due to the low AN content in the plant as AN is only synthesized within the glandular trichomes. Therefore, genetic engineering of A. annua is one of the most promising approaches for improving the yield of AN. In this work, the AaMYB1 transcription factor has been identified and characterized. When AaMYB1 is overexpressed in A. annua, either exclusively in trichomes or in the whole plant, essential AN biosynthetic genes are also overexpressed and consequently the amount of AN is significantly increased. Artemisia AaMYB1 constitutively overexpressing plants displayed a greater number of trichomes. In order to study the role of AaMYB1 on trichome development and other possibly connected biological processes, AaMYB1 was overexpressed in Arabidopsis thaliana. To support our findings in Arabidopsis thaliana, an AaMYB1 orthologue from this model plant, AtMYB61, was identified and atmyb61 mutants characterized. Both AaMYB1 and AtMYB61 affected trichome initiation, root development and stomatal aperture in A. thaliana. Molecular analyses indicated that two crucial trichome activator genes are misexpressed in atmyb61 mutant plants and in plants overexpressing AaMYB1. Furthermore, AaMYB1 and AtMYB61 are also essential for gibberellin (GA) biosynthesis and degradation in both species by positively affecting the expression of the enzymes that convert GA into the bioactive GA as well as the enzymes involved in the degradation of GA . Overall, these results identify AaMYB1/AtMYB61 as a key component of the molecular network that connects important biosynthetic processes, and reveal its potential value for AN production through genetic engineering.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Arabidopsis Proteins); 0 (Gibberellins); 0 (MYB61 protein, Arabidopsis); 0 (Myb protein, Arabidopsis); 0 (Transcription Factors)


  9 / 437 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
PMID:28052518
Autor:Wan X; Jiang L; Zhong H; Lu Y; Zhang L; Wang T
Endereço:College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, Jiangsu, China.
Título:Effects of enzymatically treated Artemisia annua L. on growth performance and some blood parameters of broilers exposed to heat stress.
Fonte:Anim Sci J; 88(8):1239-1246, 2017 Aug.
ISSN:1740-0929
País de publicação:Australia
Idioma:eng
Resumo:To evaluate the effects of enzymatically treated Artemisia annua L. (EA) on growth performance and some blood parameters of broilers exposed to heat stress (HS), 320 22-day-old Arbor Acres male broilers were randomly allotted into five groups with eight replicates of eight birds each. Broilers in the control group were housed at 22 ± 1°C and fed the basal diet. Broilers in the HS, HS-EA , HS-EA and HS-EA groups were reared under HS (34 ± 1°C for 8 h/day and 22 ± 1°C for 16 h/day), and fed basal diet with 0, 0.75, 1.00 and 1.25 g/kg EA, respectively. The experiment ended at 42 days. Dietary 1.00 and 1.25 g/kg EA decreased blood pH and elevated body weight gain, feed intake and carcass yield compared to the HS group. Broilers fed EA diets had lower serum concentrations of malondialdehyde and corticosterone and activities of alanine aminotransferase and aspartate aminotransferase, and higher serum total superoxide dismutase activity, tri-iodothyronine concentration and tri-iodothyronine/thyroxine than the HS group. Serum catalase activity in HS-EA and HS-EA groups and activity to inhibit hydroxyl in the HS-EA group were higher than the HS group. In conclusion, dietary 0.75-1.25 g/kg EA addition alleviated HS induced impairments in broilers.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:06LU7C9H1V (Triiodothyronine); 4Y8F71G49Q (Malondialdehyde); EC 1.15.1.1 (Superoxide Dismutase); EC 2.6.1.1 (Aspartate Aminotransferases); EC 2.6.1.2 (Alanine Transaminase); Q51BO43MG4 (Thyroxine); W980KJ009P (Corticosterone)


  10 / 437 MEDLINE  
              first record previous record
seleciona
para imprimir
Fotocópia
Texto completo
PMID:27928651
Autor:Zhou L; Yang G; Sun H; Tang J; Yang J; Wang Y; Garran TA; Guo L
Endereço:The State Key Laboratory Breeding Base of Dao-di Herbs, National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China.
Título:Effects of different doses of cadmium on secondary metabolites and gene expression in Artemisia annua L.
Fonte:Front Med; 11(1):137-146, 2017 Mar.
ISSN:2095-0225
País de publicação:China
Idioma:eng
Resumo:This study aims to elucidate the underlying molecular mechanisms of artemisinin accumulation induced by Cd. The effects of different Cd concentrations (0, 20, 60, and 120 µmol/L) on the biosynthesis of Artemisia annua L. were examined. Intermediate and end products were quantified by HPLC-ESI-MS/MS analysis. The expression of key biosynthesis enzymes was also determined by qRT-PCR. The results showed that the application of treatment with 60 and 120 µmol/L Cd for 3 days significantly improved the biosynthesis of artemisinic acid, arteannuin B, and artemisinin. The concentrations of artemisinic acid, arteannuin B, and artemisinin in the 120 µmol/L Cd-treated group were 2.26, 102.08, and 33.63 times higher than those in the control group, respectively. The concentrations of arteannuin B and artemisinin in 60 µmol/L Cd-treated leaves were 61.10 and 26.40 times higher than those in the control group, respectively. The relative expression levels of HMGR, FPS, ADS, CYP71AV1, DBR2, ALDH1, and DXR were up-regulated in the 120 µmol/L Cd-treated group because of increased contents of artemisinic metabolites after 3 days of treatment. Hence, appropriate doses of Cd can increase the concentrations of artemisinic metabolites at a certain time point by up-regulating the relative expression levels of key enzyme genes involved in artemisinin biosynthesis.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Artemisinins); 0 (Plant Extracts); 00BH33GNGH (Cadmium)



página 1 de 44 ir para página                         
   


Refinar a pesquisa
  Base de dados : MEDLINE Formulário avançado   

    Pesquisar no campo  
1  
2
3
 
           



Search engine: iAH v2.6 powered by WWWISIS

BIREME/OPAS/OMS - Centro Latino-Americano e do Caribe de Informação em Ciências da Saúde