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2.
J Pediatric Infect Dis Soc ; 11(Supplement_3): S79-S84, 2022 Oct 31.
Article in English | MEDLINE | ID: mdl-36314549

ABSTRACT

Global efforts to eliminate tuberculosis (TB) must address the unique barriers that children (ages 0 through 9 years) and adolescents/young adults (AYA; ages 10 through 24 years) face in adhering to treatment for TB infection and disease. We conducted a narrative review to summarize current knowledge on the social determinants of treatment adherence among these age groups to guide efforts and policy to address their unique needs. Our findings revealed that research on TB treatment adherence among children and AYA is still in its nascent stage. The current literature revealed structural/community-, health system-, household-, and individual-level factors that influence treatment adherence and varied with developmental stage. There is a need to develop multilevel interventions to address the unique challenges that children and AYA face in adhering to TB treatment.


Subject(s)
Latent Tuberculosis , Tuberculosis , Child , Adolescent , Young Adult , Humans , Infant, Newborn , Social Determinants of Health , Tuberculosis/drug therapy , Family Characteristics
3.
An Acad Bras Cienc ; 93(4): e20200443, 2021.
Article in English | MEDLINE | ID: mdl-34495202

ABSTRACT

Phytochemical studies of Cespedesia spathulata (Ochnaceae) leaves using 1H, 13C NMR, and GC-MS have led to the isolation of some metabolites identified for the first time in these species such as cathechin, epicatechin, vitexin, orientin, 6''-O-acetyl-vitexin, sitosterol, stigmasterol, phytol, 4,5-dihydrovomifoliol and a mixture of aliphatic methyl esters, together with ochnaflavone, which was previously isolated from this plant. The modulating activity of some fractions and compounds from Cespedesia spathulata towards tyrosinase enzyme was assayed by spectroscopic and theoretical means/experiments. The dichloromethane fraction (133 µg mL-1) and ochnaflavone (333 µM) inhibited tyrosinase activity by 20 % and 2.0 %, respectively, whereas the ethyl acetate fraction (666 µg mL-1) and ±catechins (catechin and epicatechin - 800 µM) activated it by 104 % and 384 %, respectively. Quantum chemical calculations suggested that catechin and epicatechin are better activators than L-DOPA by interacting with Cu (II) ions. Molecular docking results suggested that hydrogen bonding and hydrophobic interactions are the main binding forces between each tyrosinase activator and the amino acid residues inside the active protein binding pocket.


Subject(s)
Ochnaceae , Molecular Docking Simulation , Monophenol Monooxygenase , Phytochemicals/pharmacology , Plant Extracts/pharmacology , Plant Leaves
4.
Am J Trop Med Hyg ; 103(6): 2492-2500, 2020 12.
Article in English | MEDLINE | ID: mdl-32959763

ABSTRACT

Since 2018, adolescents have been included as a target group for tuberculosis (TB) surveillance by the WHO. However, they are considered a neglected population, as there are considerable gaps in information about them. We aimed to analyze the risk factors for unfavorable TB treatment outcomes among adolescents in Rio de Janeiro, a Brazilian city with a high burden of TB. This is a retrospective study of adolescents (10-18 years) with TB notified in Rio de Janeiro, from four national database systems, covering 2014-2016. "Extreme vulnerability" was defined as adolescents who presented one of the following characteristics: homelessness, incarceration, tobacco use, illicit drug use, or alcohol abuse. Logistic regression analysis was used to identify factors associated with favorable (cure/completed treatment) and unfavorable outcomes (lost to follow-up, death, and treatment failure). A total of 725 adolescents with TB were included: 610 (84.1%) were cured, 94 (13%) were lost to follow-up, six (0.8%) died because of TB, 13 (1.8%) died because of other causes, and two (0.3%) failed treatment. Unfavorable outcomes were associated with retreatment (adjusted odds ratio [aOR]: 4.51; 95% CI: 2.23-9.17), TB-HIV coinfection (aOR: 10.15; 95% CI: 4.15-25.34), extreme vulnerability (aOR: 3.01; 95% CI: 1.70-5.33), and living in the two districts (3.1 and 3.3) with worst conditions: large population and rates of homicides and shantytowns (aOR: 4.11; 95% CI: 1.79-9.46 and aOR: 5.35; 95% CI: 2.20-13.03, respectively). Our findings underscore the need for strengthening early identification and interventions for adolescents at high risk of unfavorable outcomes, especially those living in shantytowns.


Subject(s)
Tuberculosis, Pulmonary/epidemiology , Tuberculosis, Pulmonary/pathology , Adolescent , Antitubercular Agents/therapeutic use , Brazil/epidemiology , Child , Coinfection/epidemiology , Coinfection/pathology , Female , HIV Infections/complications , HIV Infections/epidemiology , Humans , Male , Odds Ratio , Retrospective Studies , Risk Factors , Treatment Failure , Treatment Outcome
5.
Int J Biol Macromol ; 160: 1114-1129, 2020 Oct 01.
Article in English | MEDLINE | ID: mdl-32450323

ABSTRACT

The present work reports the biological assays between synthetic BF2-naphtyridine complexes and four proteins: human serum albumin (HSA), calf-thymus DNA (CT-DNA), tyrosinase and acetylcholinesterase enzymes via spectroscopic analysis at physiological conditions, combined with molecular docking simulations. The BF2-complexes presented spontaneous and moderate binding ability to HSA through the ground-state association (static fluorescence quenching mechanism). The main binding site is Sudlow's site I (subdomain IIA) and the binding does not perturb significantly both secondary and surface structure of HSA. Despite BF2-complexes showed good binding ability with HSA, these compounds presented weak intercalative ability with CT-DNA (the most conventional and simple model to preliminary studies), except in the case of 1 h, which suggested that the presence of electronic donor groups in both aromatic ring moieties of BF2-complex structure can increase the intercalative ability for DNA strands. Competitive binding displacement assays in the presence of methyl green and molecular docking calculations indicated that the studied compounds interact preferentially in the major groove of DNA. In addition, the assayed compounds presented the ability to activate or inhibit both tyrosinase (the decontrolled activity can induce melanoma carcinoma) or AChE (involved in reactions related to the function of neurotransmitters) enzymes.


Subject(s)
Acetylcholinesterase/chemistry , Boron Compounds/chemistry , Cholinesterase Inhibitors/chemical synthesis , Monophenol Monooxygenase/chemistry , Naphthyridines/chemistry , Acetylcholinesterase/metabolism , Binding Sites , Cholinesterase Inhibitors/pharmacology , DNA/chemistry , DNA/metabolism , Humans , Molecular Docking Simulation , Monophenol Monooxygenase/antagonists & inhibitors , Monophenol Monooxygenase/metabolism , Protein Binding , Serum Albumin/chemistry , Serum Albumin/metabolism
6.
Parasitol Res ; 118(3): 955-967, 2019 Mar.
Article in English | MEDLINE | ID: mdl-30693380

ABSTRACT

Water buffalo is important livestock in several countries in the Latin American and Caribbean regions. This buffalo species can be infected by tick-borne hemoparasites and remains a carrier of these pathogens which represent a risk of infection for more susceptible species like cattle. Therefore, studies on the epidemiology of tick-borne hemoparasites in buffaloes are required. In this study, the prevalence of Babesia bovis, Babesia bigemina, and Anaplasma marginale were determined in water buffalo herds of western Cuba. To this aim, a cross-sectional study covering farms with large buffalo populations in the region was performed. Eight buffalo herds were randomly selected, and blood samples were collected from 328 animals, including 63 calves (3-14 months), 75 young animals (3-5 years), and 190 adult animals (> 5 years). Species-specific nested PCR and indirect ELISA assays were used to determine the molecular and serological prevalences of each hemoparasite, respectively. The molecular and serological prevalence was greater than 50% for the three hemoparasites. Differences were found in infection prevalence among buffalo herds, suggesting that local epidemiological factors may influence infection risk. Animals of all age groups were infected, with a higher molecular prevalence of B. bigemina and A. marginale in young buffalo and calves, respectively, while a stepwise increase in seroprevalence of B. bovis and B. bigemina from calves to adult buffaloes was found. The co-infection by the three pathogens was found in 12% of animals, and when analyzed by pair, the co-infections of B. bovis and B. bigemina, B. bigemina and A. marginale, and B. bovis and A. marginale were found in 20%, 24%, and 26%, respectively, underlying the positive interaction between these pathogens infecting buffaloes. These results provide evidence that tick-borne pathogen infections can be widespread among water buffalo populations in tropical livestock ecosystems. Further studies should evaluate whether these pathogens affect the health status and productive performance of water buffalo and infection risk of these pathogens in cattle cohabiting with buffalo.


Subject(s)
Anaplasma marginale , Anaplasmosis/complications , Babesia , Babesiosis/parasitology , Buffaloes/parasitology , Anaplasmosis/epidemiology , Animals , Babesiosis/complications , Babesiosis/epidemiology , Cattle , Coinfection , Cross-Sectional Studies , Cuba/epidemiology , Enzyme-Linked Immunosorbent Assay , Female , Phylogeny , Polymerase Chain Reaction , Seroepidemiologic Studies , Ticks
7.
Bioorg Chem ; 81: 79-87, 2018 12.
Article in English | MEDLINE | ID: mdl-30118988

ABSTRACT

A series of N-aryl-2-phenyl-hydrazinecarbothioamides have been investigated as possible inhibitors of tyrosinase, an enzyme involved in the development of melanomas. The hydrazinecarbothioamides 1-6 were synthesized from the reaction between phenylhydrazine and isothiocyanates, for which three different methods have been employed, namely stirring at room temperature, by microwave irradiation or by mechanochemical grinding. Quantitative yields were obtained for the later technique. Compound 4 showed the best value for tyrosinase inhibition (IC50 = 22.6 µM), which occurs through an uncompetitive mechanism. Molecular docking results suggested that 4 can interact via T-stacking with the substrate L-DOPA and via hydrogen bonding and hydrophobic forces with the amino acid residues Ala-79, His-243, Val-247, Phe-263, Val-282, and Glu-321. The interaction between human serum albumin (HSA) and compound 4 occurs through a ground state association and does not perturb the secondary structure of the albumin as well as the microenvironment around Tyr and Trp residues. The binding is spontaneous, moderate and occurs mainly in the Sudlow's site I. Molecular docking results suggested hydrogen bonding, hydrophobic and electrostatic interactions as the main binding forces between the compound 4 and the amino acid residues Lys-198, Trp-214, Glu-449, Leu-452, and Leu-480.


Subject(s)
Enzyme Inhibitors/pharmacology , Hydrazines/pharmacology , Monophenol Monooxygenase/antagonists & inhibitors , Serum Albumin, Human/antagonists & inhibitors , Thioamides/pharmacology , Dose-Response Relationship, Drug , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , Humans , Hydrazines/chemical synthesis , Hydrazines/chemistry , Molecular Docking Simulation , Molecular Structure , Monophenol Monooxygenase/metabolism , Serum Albumin, Human/chemistry , Structure-Activity Relationship , Thioamides/chemical synthesis , Thioamides/chemistry
8.
Ticks Tick Borne Dis ; 9(5): 1115-1119, 2018 07.
Article in English | MEDLINE | ID: mdl-29693549

ABSTRACT

The present study evaluated whether a natural dietary additive, dried Artemisia annua leaves, may be useful to control Rhipicephalus (Boophilus) microplus on naturally infested cattle. Twenty heifers of the Canchim breed, weighing around 250 kg, were divided into two equally sized experimental groups: 1) control animals and 2) animals receiving 200 g/day of dried A. annua leaves for two months. Before treatment began, the animals were homogeneously distributed in control and treatment groups based on their pre-treatment weight and tick infestation level. Counts of engorged female ticks then occurred weekly during the two-month experimental period. We also monitored cattle weight gain and packed cell volume (PCV). Artemisinin (0.96%) was quantified in the plant material by high-performance liquid chromatography with refractive index detector (HPLC-IR). No statistical differences between the control and treatment groups were observed for engorged female counts (log averages of 1.3 ticks and 1.4 ticks per animal, respectively), daily cattle weight gain (0.910 kg and 0.888 kg, respectively) or PCV (33.5% and 33.0%, respectively). We conclude that the oral supplementation of cattle feed with dried A. annuna leaves did not control natural infestation of R. (B.) microplus. The hypothesis of artemisinin's action on cattle ticks by ingestion through the animals' blood was not confirmed at the evaluated dose.


Subject(s)
Artemisia annua/anatomy & histology , Artemisinins/administration & dosage , Cattle Diseases/diet therapy , Food Additives/administration & dosage , Rhipicephalus/drug effects , Tick Infestations/veterinary , Acaricides/therapeutic use , Animal Feed/analysis , Animals , Artemisia annua/chemistry , Artemisinins/analysis , Artemisinins/isolation & purification , Cattle , Female , Food, Preserved , Male , Plant Leaves/chemistry , Tick Infestations/diet therapy , Weight Gain/drug effects
9.
Int J Biol Macromol ; 112: 1062-1072, 2018 Jun.
Article in English | MEDLINE | ID: mdl-29447969

ABSTRACT

A novel series of piperonal mesoionic derivatives (PMI 1-6) was synthesized. Tyrosinase inhibition in the presence of PMI-1, -2, -3, -4, -5 and -6 as well as human serum albumin (HSA) binding studies with PMI-5 and PMI-6 were done by spectroscopic and theoretical methods. The mesoionic compound PMI-5 is the most promising tyrosinase inhibitor with a noncompetitive inhibitory mechanism and an IC50=124µmolL-1. In accordance with the kinetic profile, molecular docking results show that PMI-5 is able to interact favorably with the tyrosinase active site containing the substrate molecule, L-DOPA, interacting with Val-247, Phe-263 and Val-282 residues. The spectroscopic results for the interaction HSA:PMI-5 and HSA:PMI-6 indicated that these mesoionic compounds can associate with HSA in the ground state and energy transfer can occur with high probability. The binding was moderate, spontaneous and can perturb significantly the secondary structure of the albumin. The molecular docking results suggest that PMI-5 and PMI-6 are able to be accommodated inside the Sudlow's site I in HSA, interacting with hydrophobic and hydrophilic amino acid residues.


Subject(s)
Aniline Compounds/chemical synthesis , Aniline Compounds/pharmacology , Benzaldehydes/chemical synthesis , Benzaldehydes/pharmacology , Benzodioxoles/chemical synthesis , Benzodioxoles/pharmacology , Monophenol Monooxygenase/antagonists & inhibitors , Serum Albumin, Human/metabolism , Aniline Compounds/chemistry , Benzaldehydes/chemistry , Benzodioxoles/chemistry , Binding Sites , Circular Dichroism , Energy Transfer , Humans , Ions , Kinetics , Molecular Docking Simulation , Monophenol Monooxygenase/metabolism , Protein Binding , Protein Structure, Secondary , Serum Albumin, Human/chemistry , Spectrometry, Fluorescence , Thermodynamics
10.
Vet Parasitol Reg Stud Reports ; 13: 180-187, 2018 08.
Article in English | MEDLINE | ID: mdl-31014871

ABSTRACT

Water buffalo (Bubalus bubalis) is a potential reservoir for Anaplasma marginale in livestock ecosystems of tropical countries. However, their participation in the epidemiological process of bovine anaplasmosis in endemic areas remains unclear. In the present study, the reservoir competence of water buffalo for A. marginale was explored by focusing on the analysis of rickettsemia levels in carrier animals, and the genetic characterization of A. marginale strains from cattle and buffalo. Eight groups of cattle and water buffaloes were randomly selected from cohabiting herds in four livestock ecosystems of Cuba, together with two control groups from unrelated cattle and buffalo herds. A total of 180 adult animals (88 water buffalo and 92 cattle) were sampled. Rickettsemia in carrier animals was determined by quantitative real-time PCR. The rickettsemia (parasitemia) levels in cattle were higher than in buffaloes, however the rickettsemia in buffalo may be enough to infect R. microplus ticks. The genetic diversity of A. marginale was assessed by strain characterization and phylogenetic analysis of 27 msp1α gene sequences. The results showed genetic similarity among strains from cattle and water buffalo, suggesting the occurrence of cross-species transmission.


Subject(s)
Anaplasma marginale/genetics , Anaplasmosis/epidemiology , Buffaloes/microbiology , Cattle Diseases/epidemiology , Disease Reservoirs/veterinary , Anaplasmosis/transmission , Animals , Bacterial Outer Membrane Proteins/genetics , Cattle/microbiology , Cattle Diseases/microbiology , Cattle Diseases/transmission , Cohort Studies , Cuba/epidemiology , Disease Reservoirs/microbiology , Genetic Variation , Phylogeny , Real-Time Polymerase Chain Reaction , Ticks/microbiology
11.
Bioorg Med Chem Lett ; 27(15): 3546-3550, 2017 08 01.
Article in English | MEDLINE | ID: mdl-28583798

ABSTRACT

In the search for compounds which may inhibit the development of melanomas, a series of thiosemicarbazones has been investigated as possible inhibitors of the tyrosinase enzyme. The results showed that all the thiosemicarbazones tested exhibited significant inhibitory effects on the enzyme. Thiosemicarbazones Thio-1, Thio-2, Thio-3 and Thio-4 substituted with oxygenate moieties, were better inhibitors (IC50 0.42, 0.35, 0.36 and 0.44mM, respectively) than Thio-5, Thio-6, Thio-7 and Thio-8. For the better inhibitors, molecular docking results suggested that the oxygen present in the para position of the aromatic ring is essential for the tyrosinase inhibition, due its high ability for complexation with Cu2+ ions. Inside the active protein pocket, Thio-2 - the best studied inhibitor - is able to interact with the amino acid residues His-155, Gly-170 and Val-172 via hydrogen bonding and hydrophobic force. Thio-2, containing a substituent on the aromatic ring similar to the substrate l-DOPA, showed a competitive inhibition mechanism as viewed in a Lineweaver-Burk plot. The same results were observed in the UV-Vis curves.


Subject(s)
Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Monophenol Monooxygenase/antagonists & inhibitors , Thiosemicarbazones/chemistry , Thiosemicarbazones/pharmacology , Agaricales/drug effects , Agaricales/enzymology , Humans , Levodopa/metabolism , Melanins/metabolism , Melanoma/drug therapy , Melanoma/enzymology , Molecular Docking Simulation , Monophenol Monooxygenase/metabolism
12.
Pesqui. vet. bras ; 36(8): 711-718, Aug. 2016. tab, graf, ilus
Article in English | LILACS, VETINDEX | ID: lil-797989

ABSTRACT

The protein profiles and proteolytic activity of the excretory secretory products (E/SP) of the first (L1), second (L2) and third (L3) larval stages of Cochliomyia hominivorax were studied in the laboratory. Analysis on the E/SP protein profile was carried out using polyacrylamide gel containing sodium dodecyl sulfate (SDS-PAGE). The E/SP of each larval stage (L1, L2 and L3) treated with protease inhibitors, containing 30µg, 40µg and 50µg of protein, was applied to the 10% polyacrylamide gel. The proteolytic activity of the crude E/SP was analyzed in gels copolymerized with gelatin and by colorimetric assays using azocasein as a substrate, with the characterization of the proteases using synthetic inhibitors. Different protein profiles were observed for the larval instars, with L1 presenting the most complex profile. Nevertheless, various protein bands were observed that were common to all the larval instars. The E/SP of all the instars showed proteolytic activity on gelatin, evidenced by proteolysis zones, predominantly with apparently higher molecular masses in L1, while for L2 and L3 the proteolysis zones could also be observed in regions with lower masses. Tests with protease inhibitors using gelatin as substrate showed that the E/SP of larvae were mainly composed of serine proteases. Additionally, inhibition was observed in L2 E/SP treated previously with EDTA, an inhibitor of metalloproteases. The assays with azocasein revealed a gradual increase of proteolytic activity on this substrate with larval development progress, with the strongest inhibitions being observed after treatments with 3,4-dichloroisocoumarin (DCI) for E/SP of L1, L2 and L3. These results suggest that C. hominivorax larvae produce different proteases, a fact that can be related to the parasite's vital processes for survival, such as penetration into the host's tissues and nutrition during the larval stage.(AU)


Os perfis protéicos e a atividade proteolítica dos produtos de excreção/secreção (PE/S) das larvas de primeiro (L1), segundo (L2) e terceiro (L3) estágios de Cochliomyia hominivorax foram estudados em laboratório. Os perfis protéicos foram obtidos por eletroforese em géis de poliacrilamida (SDS-PAGE). Os PE/S de cada fase larval (L1, L2 e L3), tratados com inibidores de proteases, contendo 30µg, 40µg e 50µg de proteína, foram aplicados em géis de poliacrilamida a 10%. A atividade proteolítica dos PE/S na sua forma nativa, foi analisada em géis co-polimerizados com gelatina e por testes colorimétricos usando a azocaseína como substrato, com a caracterização das proteases feita por meio de inibidores sintéticos. Diferentes perfis protéicos foram observados para os instares larvais, com L1 apresentando o perfil mais complexo. Apesar disso, foram observadas várias bandas protéicas comuns a todos os estágios larvais. Os PE/S de todos os instares mostraram atividade proteolítica sobre a gelatina, evidenciada por zonas de proteólise, com predominância de massas moleculares aparentes mais altas em L1, enquanto que para L2 e L3 as zonas de proteólise puderam ser observadas também em regiões de menores massas. Os testes com inibidores de proteases usando a gelatina como substrato mostraram que os PE/S de L1, L2 e L3 eram compostos principalmente de serina-proteases. Adicionalmente, inibição foi observada nos PE/S de L2 tratada previamente com EDTA, um inibidor de metalo-proteases. Os ensaios com a zocaseína revelaram um aumento gradual da atividade proteolítica sobre este substrato com o progresso do desenvolvimento larval, com a mais forte inibição sendo observada após o tratamento com 3,4 dicloroisocumarina (DCI) para os PE/S de L1, L2 e L3. Estes resultados sugerem que as larvas de C. hominivorax produzem diferentes proteases, fato que pode estar relacionado a processos vitais para a sobrevivência do parasita, tais como a penetração nos tecidos dos hospedeiros e nutrição durante os estágios larvais.(AU)


Subject(s)
Animals , Diptera , Larva/physiology , Peptide Hydrolases/analysis , Serine Proteases , Electrophoresis, Polyacrylamide Gel , Myiasis/veterinary , Protease Inhibitors
13.
Rev. bras. farmacogn ; 26(3): 321-325, May-June 2016. tab, graf
Article in English | LILACS | ID: lil-784288

ABSTRACT

Abstract The aim of the current study is to evaluate the effect of Acmella oleracea (L.) R.K. Jansen, Asteraceae, methanolic extract, hexane (84.28% spilanthol) and dichloromethane (approximately 100% spilanthol) fractions on the tyrosinase enzyme. The dehydrated jambu extract was obtained through maceration using methanol. The extract residue was solubilized in MeOH/H2O (8:2) and subjected to liq.–liq. partition in organic solvents. Both the extraction and the partition procedures were conducted with three replicates. The analyses were performed using GC–MS, 1H and 13C NMR. The hexane fraction provided samples containing 84.28, 82.91 and 62.83% spilanthol in repetitions 1, 2 and 3, respectively. The dichloromethane fraction showed 88.55% spilanthol in repetition 1, and approximately 100% spilanthol in repetitions 2 and 3. The jambu extract as well as the hexane fraction (84.28% spilanthol) were able to activate the oxidizing activity of the tyrosinase enzyme for L-DOPA. The dichloromethane fraction (approximately 100% spilanthol) showed stronger inhibition effect on the tyrosinase enzyme in the first 10 min. The results raise the interest in study in spilanthol formulations for topical use, since it may prevent and/or slow skin hyperpigmentation or depigmentation processes. Furthermore, spilanthol may be used to control the enzymatic browning in fruits and vegetables.

14.
Molecules ; 20(10): 19526-39, 2015 Oct 27.
Article in English | MEDLINE | ID: mdl-26516829

ABSTRACT

In the North of Brazil (Pará and Amazonas states) the leaves of the plant Talinum triangulare (popular: cariru) replace spinach as food. From a phytochemical point of view, they are rich in compounds of the group of pheophytins. These substances, related to chlorophyll, have photophysical properties that give them potential application in photodynamic therapy. Human serum albumin (HSA) is one of the main endogenous vehicles for biodistribution of molecules by blood plasma. Association constants and thermodynamic parameters for the interaction of HSA with pheophytin from Talinum triangulare were studied by UV-Vis absorption, fluorescence techniques, and molecular modeling (docking). Fluorescence quenching of the HSA's internal fluorophore (tryptophan) at temperatures 296 K, 303 K, and 310 K, resulted in values for the association constants of the order of 104 L∙mol(-1), indicating a moderate interaction between the compound and the albumin. The negative values of ΔG° indicate a spontaneous process; ΔH° = 15.5 kJ∙mol(-1) indicates an endothermic process of association and ΔS° = 0.145 kJ∙mol(-1)∙K(-1) shows that the interaction between HSA and pheophytin occurs mainly by hydrophobic factors. The observed Trp fluorescence quenching is static: there is initial non-fluorescent association, in the ground state, HSA:Pheophytin. Possible solution obtained by a molecular docking study suggests that pheophytin is able to interact with HSA by means of hydrogen bonds with three lysine and one arginine residues, whereas the phytyl group is inserted in a hydrophobic pocket, close to Trp-214.


Subject(s)
Cactaceae/chemistry , Molecular Docking Simulation/methods , Pheophytins/chemistry , Serum Albumin/chemistry , Binding Sites , Humans , Hydrogen Bonding , Models, Molecular , Molecular Structure , Photochemotherapy , Plant Leaves/chemistry , Spectrometry, Fluorescence/methods
15.
Vet Parasitol ; 205(1-2): 277-84, 2014 Sep 15.
Article in English | MEDLINE | ID: mdl-25085774

ABSTRACT

The present study aimed to evaluate the acaricidal action of the chemically modified essential oil of Cymbopogon spp. and Corymbia citriodora on Rhipicephalus (Boophilus) microplus. Citronellal was converted into N-butylcitronellylamine and in N-prop-2-inylcitronellylamine, analogs of juvenoids, by reductive amination using butylamine (N1 to N3) and propargylamine (N4 to N7). In vitro assays included the adult immersion, and larval packet tests. Engorged females were weighed in groups of 10 and tested in three replicates for six concentrations. They were immersed in the modified oils or control solution and incubated. In the larval packet test, the same substances and concentrations were evaluated in three replicates. In the in vivo test, six pastured heifers naturally infested with R. (B.) microplus were used per treatment: negative control, positive control (amitraz, Triatox(®)), original oil of C. citriodora at 1.5%, and modified oil containing 0.9% N-prop-2-inylcitronellylamine (N7). Ticks were counted in the right side of the body in 24 animals from day D-3 to D21. LC50 and LC90 were obtained by Probit analysis, while the in vivo results were log transformed and compared using the Tukey test. Among the nitrocellylamines tested in vitro, N6 was most effective on the engorged females (100% efficacy at 50mg/mL) and N7 on the larvae (100% efficacy at 6.25mg/mL). In the test with larvae, the original oil of C. citriodora was less effective than the counterpart modified oil (N7), proving that the chemical modification optimized its effect. In the in vivo test, no significant difference was observed between N7 and the negative control. The average numbers of ticks on the animals' right side were 32.8, 8.1, 37.9 and 35.4 for the negative control, positive control, original oil and N7, respectively. The chemical modification improved the efficacy in vitro, but it was not observed in vivo, perhaps due to the low stability of the amines under field conditions. The evaluation carried out here has not been previously studied, so this concept expands the horizon for research into chemically modified substances for parasite control and shed light on the challenges to find effective formulations and application methods.


Subject(s)
Acaricides/pharmacology , Cymbopogon/chemistry , Myrtaceae/chemistry , Oils, Volatile/pharmacology , Plant Oils/pharmacology , Rhipicephalus/drug effects , Acaricides/chemistry , Animals , Cattle , Cattle Diseases/parasitology , Cattle Diseases/prevention & control , Female , Larva/drug effects , Tick Infestations/prevention & control , Tick Infestations/veterinary
16.
Parasitol Res ; 113(6): 2345-53, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24802864

ABSTRACT

There is no effective natural alternative control for gastrointestinal nematodes (GIN) of small ruminants, with Haemonchus contortus being the most economically important GIN. Despite frequent reports of multidrug-resistant GIN, there is no new commercial anthelmintic to substitute failing ones. Although trematocidal activity of artemisinin analogs has been reported in sheep, neither artemisinin nor its plant source (Artemisia annua) has been evaluated for anthelmintic activity in ruminants. This study evaluated the anthelmintic activity of A. annua crude extracts in vitro and compared the most effective extract with artemisinin in sheep naturally infected with H. contortus. A. annua leaves extracted with water, aqueous 0.1% sodium bicarbonate, dichloromethane, and ethanol were evaluated in vitro by the egg hatch test (EHT) and with the bicarbonate extract only for the larval development test (LDT) using H. contortus. The A. annua water, sodium bicarbonate (SBE), ethanol, and dichloromethane extracts tested in vitro contained 0.3, 0.6, 4.4, and 9.8% of artemisinin, respectively. The sodium bicarbonate extract resulted in the lowest LC99 in the EHT (1.27 µg/mL) and in a LC99 of 23.8 µg/mL in the LDT. Following in vitro results, the SBE (2 g/kg body weight (BW)) and artemisinin (100 mg/kg BW) were evaluated as a single oral dose in naturally infected Santa Inês sheep. Speciation from stool cultures established that 84-91% of GIN were H. contortus, 8.4-15.6 % were Trichostrongylus sp., and 0.3-0.7% were Oesophagostomum sp. Packed-cell volume and eggs per gram (EPG) of feces were used to test treatment efficacy. The SBE tested in vivo contained no artemisinin, but had a high antioxidant capacity of 2,295 µmol of Trolox equivalents/g. Sheep dosed with artemisinin had maximum feces concentrations 24 h after treatment (126.5 µg/g artemisinin), which sharply decreased at 36 h. By day 15, only levamisole-treated sheep had a significant decrease of 97% in EPG. Artemisinin-treated and SBE-treated sheep had nonsignificant EPG reductions of 28 and 19%, respectively, while sheep in infected/untreated group had an average EPG increase of 95%. Sheep treated with artemisinin and A. annua SBE maintained blood hematocrits throughout the experiment, while untreated/infected controls had a significant reduction in hematocrit. This is the first time oral dose of artemisinin and an aqueous extract of A. annua are evaluated as anthelmintic in sheep. Although oral dose of artemisinin and SBE, at single doses, were ineffective natural anthelmintics, artemisinin analogs with better bioavailability than artemisinin should be tested in vivo, through different routes and in multiple doses. The maintenance of hematocrit provided by artemisinin and A. annua extract and the high antioxidant capacity of the latter suggest that they could be combined with commercial anthelmintics to improve the well-being of infected animals and to evaluate potential synergism.


Subject(s)
Anthelmintics/therapeutic use , Artemisia annua/chemistry , Haemonchiasis/veterinary , Plant Extracts/pharmacology , Sheep Diseases/parasitology , Animals , Anthelmintics/administration & dosage , Feces/parasitology , Gastrointestinal Diseases/drug therapy , Gastrointestinal Diseases/parasitology , Gastrointestinal Diseases/veterinary , Haemonchiasis/drug therapy , Haemonchus , Levamisole/pharmacology , Plant Extracts/administration & dosage , Plant Extracts/chemistry , Plant Leaves/chemistry , Sheep , Sheep Diseases/drug therapy
17.
Ticks Tick Borne Dis ; 5(3): 234-8, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24522252

ABSTRACT

The qPCR technique with SYBR Green was used to estimate the prevalence and level of Babesia bovis infection in beef cattle raised in areas endemic for babesiosis in Brazil, where the animals were continuously exposed to ticks (Rhipicephalus microplus). This is the first report in which qPCR was used to quantify and compare B. bovis DNA in blood of different cattle breeds. Blood samples were collected from 150 animals (75 cows and 75 calves) of the Angus and Nelore breeds and the first generation of an Angus and Nelore cross (AxN). Blood samples from the jugular vein were used for DNA extraction and determination of packed cell volume (PCV), while samples from peripheral veins were used for microscopic parasite detection. Although no piroplasms of B. bovis were found in blood smears, DNA amplification using qPCR revealed that all of the 150 animals, except two calves and one cow, were positive. The number of copies of B. bovis DNA was higher (p<0.05) in the Angus than in the Nelore and AxN animals, for both calves and cows, but no significant difference was found between the Nelore and AxN groups. These results suggest that a heterotic effect was present, since the results from the crossbred animals significantly deviated from the mean of the two parental groups, while closely approaching that of the Nelore group. In the Nelore and AxN groups, calves showed higher infection levels than cows (p<0.05), while for the Angus group the difference was found to be non-significant. Within each animal age group, the breed groups with higher infection levels were those with lower PCV values. However, within each breed group, no significant correlations were found between the number of DNA copies and PCV according to animal age. The qPCR method applied here allowed the observation that although there are no differences in the prevalence of infection among breed groups, Nelore and AxN cattle are able to maintain infection by B. bovis at lower levels than the Angus cattle.


Subject(s)
Animals, Newborn/parasitology , Babesia bovis/isolation & purification , Babesiosis/epidemiology , Cattle Diseases/epidemiology , Rhipicephalus/parasitology , Tick Infestations/veterinary , Animals , Babesia bovis/genetics , Babesiosis/parasitology , Brazil/epidemiology , Cattle , Cattle Diseases/parasitology , DNA, Protozoan/blood , Female , Male , Tick Infestations/epidemiology , Tick Infestations/parasitology
18.
Kidney Int ; 83(4): 707-14, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23283134

ABSTRACT

Dietary phosphorus consumption has risen steadily in the United States. Oral phosphorus loading alters key regulatory hormones and impairs vascular endothelial function, which may lead to an increase in left ventricular mass (LVM). We investigated the association of dietary phosphorus with LVM in 4494 participants from the Multi-Ethnic Study of Atherosclerosis, a community-based study of individuals who were free of known cardiovascular disease. The intake of dietary phosphorus was estimated using a 120-item food frequency questionnaire and the LVM was measured using magnetic resonance imaging. Regression models were used to determine associations of estimated dietary phosphorus with LVM and left ventricular hypertrophy (LVH). Mean estimated dietary phosphorus intake was 1167 mg/day in men and 1017 mg/day in women. After adjustment for demographics, dietary sodium, total calories, lifestyle factors, comorbidities, and established LVH risk factors, each quintile increase in the estimated dietary phosphate intake was associated with an estimated 1.1 g greater LVM. The highest gender-specific dietary phosphorus quintile was associated with an estimated 6.1 g greater LVM compared with the lowest quintile. Higher dietary phosphorus intake was associated with greater odds of LVH among women, but not men. These associations require confirmation in other studies.


Subject(s)
Hypertrophy, Left Ventricular/epidemiology , Phosphorus, Dietary/adverse effects , Aged , Aged, 80 and over , Cross-Sectional Studies , Female , Humans , Hypertrophy, Left Ventricular/ethnology , Hypertrophy, Left Ventricular/pathology , Linear Models , Logistic Models , Magnetic Resonance Imaging , Male , Middle Aged , Odds Ratio , Predictive Value of Tests , Prevalence , Risk Assessment , Risk Factors , Sex Factors , United States
19.
Ticks Tick Borne Dis ; 4(1-2): 78-82, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23312480

ABSTRACT

The present study provides the first epidemiological data on infection with Babesia bovis in cattle raised in the southwestern Brazilian Amazon. Blood clot samples were filtered through nylon cloth before being submitted to DNA extraction. PCR and nested-PCR were applied to assess the frequency of infection with B. bovis in calves with ages from 4 to 12 months bred in 4 microregions each in the states of Rondônia and Acre. After the DNA was extracted from the samples, the infection in cattle was investigated by amplification of the "rap1" gene from B. bovis. The DNA amplification results revealed a frequency of infection with B. bovis of 95.1% (272/286) in the samples from Rondônia and 96.1% (195/203) in those from Acre. The high frequency of B. bovis infection in the animals with ages from 4 to 12 months indicates a situation of enzootic stability in the regions studied. The infection rates are comparable to those detected by immunodiagnostic techniques in other endemic regions of Brazil.


Subject(s)
Babesia bovis/isolation & purification , Babesiosis/veterinary , Cattle Diseases/parasitology , Animals , Babesiosis/blood , Babesiosis/epidemiology , Babesiosis/parasitology , Brazil/epidemiology , Cattle , Cattle Diseases/blood , Cattle Diseases/epidemiology , DNA, Protozoan/blood , Polymerase Chain Reaction/veterinary , Sensitivity and Specificity
20.
Rev. bras. farmacogn ; 21(3): 397-401, maio-jun. 2011. ilus
Article in English | LILACS | ID: lil-593288

ABSTRACT

The phytochemical investigation of the roots of Piptadenia rigida Benth., Fabaceae, known as "angico", afforded sitosterol, lupeol, betuline, the chalcone isoliquiritigenin, the flavonoids, 7,4'-dihydroxyflavone, 7,3',4'-trihydroxyflavone, 7,8,3',4'-tetrahydroxyflavanone, 4-hydroxy-3,5-dimethoxybenzaldehyde and methyl-3,4-dihydroxy-benzoate. Both flavones were also isolated from the branches of this plant. Five derivatives of the aldehyde were obtained by diazomethane treatment. The structures of compounds were identified by IR, NMR and mass spectral data analysis of natural compounds and some derivatives, and by comparison with literature data.

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