Sylvia Páz Díaz-Camacho

Universidad Autónoma de Sinaloa, Cuilacan, Sinaloa, Mexico

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Publications (18)30.35 Total impact

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    ABSTRACT: Abstract Seasonality of the nematode Gnathostoma turgidum in Virginia opossums (Didelphis virginiana) in the wild has been reported; however, the mechanisms involved in deworming are unknown. We monitored the parasitologic and biologic changes in four Virginia opossums naturally infected with G. turgidum by coproparasitologic examination and abdominal ultrasonography. Eggs became detectable in the feces of opossums in May, peaked in July and August, and suddenly decreased in October. Adults of G. turgidum were expelled in the feces mainly in September. Ultrasonography of the liver showed slight damage during May. Lesions in the stomach appeared in April and persisted until September. The abnormalities of the liver and stomach were resolved in November. These data suggest that G. turgidum is likely expelled as a result of host immunologic mechanisms, although termination of a natural life span cannot be definitively excluded.
    Journal of wildlife diseases 02/2014; · 1.27 Impact Factor
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    ABSTRACT: Melanins have important pharmacological properties with limited applications due to their poor solubility. Soluble melanins have been reported in different organisms, but not in plants. In this study, aqueous soluble melanins, Impure (IMe) and Partially Purified (PMe), were prepared from the edible pulp of fruits native to Mexico (i.e. Vitex mollis, VM; Randia echinocarpa, RE; and Crescentia alata, CA). IMe and PMe were tested for their phenolics content (TPC), antioxidant activities (AA), α-glucosidase inhibition (αGI) and spectroscopic features (UV-Vis and IR). Melanins of VM showed the highest TPC (222.23 mg GAE/g) and AA (ABTS 2779.30 μmol TE/g; FRAP 1203.70 μmol TE/g). Purified melanins (PMe) showed better αGI than acarbose (IC50 = 8.38 mg/mL). The spectroscopic features of IMe and PMe corresponded to melanins and solubility may be by their complexation with carbohydrates. For the first time, plant-based soluble melanins and their remarkably high antioxidant and α-glucosidase inhibitory characteristics are presented.
    Journal of Functional Foods. 01/2014; 9:78–88.
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    ABSTRACT: Nanchi (Byrsonima crassifolia), arrayán (Psidium sartorianum) y ayale (Crescentia alata) son plantas silvestres subutilizadas de México; sus frutos son comestibles y usados como medicamentos tradicionales contra infecciones bacterianas humanas (e.g. disentería bacilar). Sin embargo, los reportes científicos que avalen los usos y promuevan su consumo son escasos. En este trabajo se determinó, ensayo de micro-dilución en caldo, la Concentración Mínima Inhibitoria (CMI) y Concentración Mínima Bactericida (CMB), de los extractos de frutos (hexánico, EH; clorofórmico, EC; y metanólico, EM) contra 21 bacterias patógenas humanas. Los EH de arrayán y ayale mostraron la mayor actividad (CMI 0.25-2 mg/mL; CMB 0.5-16 mg/mL) contra enterobacterias (Escherichia coli, Salmonella spp. y Shigella spp.). El EM de arrayán fue el más activo contra bacterias Gram positivas, presentando Staphylococcus aureus la mayor sensibilidad (CMI 2 mg/mL; CMB 2-4 mg/mL). Estos resultados apoyan el uso tradicional de estos materiales en padecimientos asociados al tratamiento de infecciones bacterianas.
    Boletin Latinoamericano y del Caribe de Plantas Medicinales y Aromaticas 01/2013; 12(4):356-364. · 0.62 Impact Factor
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    ABSTRACT: BACKGROUND: Fatty acid (FA) binding proteins (FABPs) of helminths are implicated in acquisition and utilization of host-derived hydrophobic substances, as well as in signaling and cellular interactions. We previously demonstrated that secretory hydrophobic ligand binding proteins (HLBPs) of Taenia solium metacestode (TsM), a causative agent of neurocysticercosis (NC), shuttle FAs in the surrounding host tissues and inwardly transport the FAs across the parasite syncytial membrane. However, the protein molecules responsible for the intracellular trafficking and assimilation of FAs have remained elusive. METHODOLOGY/PRINCIPAL FINDINGS: We isolated two novel TsMFABP genes (TsMFABP1 and TsMFABP2), which encoded 133- and 136-amino acid polypeptides with predicted molecular masses of 14.3 and 14.8 kDa, respectively. They shared 45% sequence identity with each other and 15-95% with other related-members. Homology modeling demonstrated a characteristic β-barrel composed of 10 anti-parallel β-strands and two α-helices. TsMFABP2 harbored two additional loops between β-strands two and three, and β-strands six and seven, respectively. TsMFABP1 was secreted into cyst fluid and surrounding environments, whereas TsMFABP2 was intracellularly confined. Partially purified native proteins migrated to 15 kDa with different isoelectric points of 9.2 (TsMFABP1) and 8.4 (TsMFABP2). Both native and recombinant proteins bound to 11-([5-dimethylaminonaphthalene-1-sulfonyl]amino)undecannoic acid, dansyl-DL-α-amino-caprylic acid, cis-parinaric acid and retinol, which were competitively inhibited by oleic acid. TsMFABP1 exhibited high affinity toward FA analogs. TsMFABPs showed weak binding activity to retinol, but TsMFABP2 showed relatively high affinity. Isolation of two distinct genes from an individual genome strongly suggested their paralogous nature. Abundant expression of TsMFABP1 and TsMFABP2 in the canal region of worm matched well with the histological distributions of lipids and retinol. CONCLUSIONS/SIGNIFICANCE: The divergent biochemical properties, physiological roles and cellular distributions of the TsMFABPs might be one of the critical mechanisms compensating for inadequate de novo FA synthesis. These proteins might exert harmonized or independent roles on lipid assimilation and intracellular signaling. The specialized distribution of retinol in the canal region further implies that cells in this region might differentiate into diverse cell types during metamorphosis into an adult worm. Identification of bioactive systems pertinent to parasitic homeostasis may provide a valuable target for function-related drug design.
    PLoS Neglected Tropical Diseases 10/2012; 6(10):e1868. · 4.57 Impact Factor
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    ABSTRACT: Gnathostomiasis is now recognized as a zoonosis with a worldwide distribution. In the Americas, it is caused by the third-stage larvae of Gnathostoma binucleatum and in Asia mainly by G. spinigerum. The availability and preparation of specific antigens are among the main obstacles for developing reliable immunodiagnostic tests. In this study, six immunodominant peptides were identified and characterized from G. binucleatum, somatic antigens (AgS: 24, 32, and 40 kDa) and excretory-secretory antigens (AgES: 42, 44, and 56 kDa) by two-dimensional immunoblot analysis. Among those immunodominant peptides, two AgS spots were characterized by mass spectrometric analysis (32 kDa; pI 6.3 and 6.5) and identified as type 1 galectins. In accordance with this finding, a fraction of AgS exhibited affinity to lactose and displayed a 100% specificity and sensitivity for the diagnosis of human gnathostomiasis.
    The American journal of tropical medicine and hygiene 09/2012; · 2.53 Impact Factor
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    ABSTRACT: Physicochemical characteristics of Ehretia tinifolia L. fruit are presented for the first time. The fruit of this plant is a small drupe of 8 mm diameter and weighs 0.2 g. Its pulp is slightly acidic (pH 5.8) with a high ratio of soluble solids (11 °Brix) to acidity (0.1%). The antioxidant activity of E. tinifolia fruits (DPPH, 303.8 mg EVC/100 g f.w.; ABTS, 84.1 mg EVC/100 g f.w.; DPPH, ABTS and EVC mean 1,1–diphenyl–2–picrylhydrazyl, 2,2'–azino–bis(3–ethylbenzothiazolin–6–sulfonate) diammonium salt, and equivalents of vitamin C, respectively) was similar or higher than reported for several tropical fruits (e.g. orange, guava, and prickly pear). Ehretia tinifolia fruit has a high content of ash (12.6 mg/100 g d.w.). The edible portion is an important source of selenium (0.1 mg/100 g d.w.) and total fatty acids were 834.8 mg/100g d.w.; the main fatty acids were palmitic (27.6%), linoleic (26.4%), linolenic (18.1%), and oleic (17.6%). The content of fatty acids of seeds was 5 137.5 mg/100 g d.w., with linoleic (54.3%), oleic (22.9%), and palmitic (12.7%) as main components.
    REVISTA MEXICANA DE BIODIVERSIDAD 03/2012; 83(1):273-280. · 0.39 Impact Factor
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    ABSTRACT: A series of hydropyridines (HP's) were synthesized using dimedones, ethyl acetoacetate, ammonium acetate and appropriate aldehydes under solvent-free conditions and microwave-irradiation through Hantzsch reaction. All the synthesized HP's were tested in vitro for the 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity and structure–activity relationship was discussed; only 12 out of the 36 HP's showed antioxidant activity. Polyhydroquinolines (PHQ's) were the most active compounds among the studied HP's, they were characterized by the lack of an ester-like structure substituent at carbon 5.
    RSC Advances 02/2012; 2(5):1827-1834. · 3.71 Impact Factor
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    ABSTRACT: Physicochemical characteristics of Ehretia tinifolia L. fruit are presented for the first time. The fruit of this plant is a small drupe of 8 mm diameter and weighs 0.2 g. Its pulp is slightly acidic (pH 5.8) with a high ratio of soluble solids (11 ºBrix) to acidity (0.1%). The antioxidant activity of E. tinifolia fruits (DPPH, 303.8 mg EVC/100 g f.w.; ABTS, 84.1 mg EVC/100 g f.w.; DPPH, ABTS and EVC mean 1,1-diphenyl-2-picrylhydrazyl, 2,2’-azino-bis(3-ethylbenzothiazolin-6-sulfonate) diammonium salt, and equivalents of vitamin C, respectively) was similar or higher than reported for several tropical fruits (e.g. orange, guava, and prickly pear). Ehretia tinifolia fruit has a high content of ash (12.6 mg/100 g d.w.). The edible portion is an important source of selenium (0.1 mg/100 g d.w.) and total fatty acids were 834.8 mg/100g d.w.; the main fatty acids were palmitic (27.6%), linoleic (26.4%), linolenic (18.1%), and oleic (17.6%). The content of fatty acids of seeds was 5 137.5 mg/100 g d.w., with linoleic (54.3%), oleic (22.9%), and palmitic (12.7%) as main components.
    REVISTA MEXICANA DE BIODIVERSIDAD 01/2012; 83(1):273-280. · 0.39 Impact Factor
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    ABSTRACT: Se realizó la primera caracterización fisicoquímica y nutricional de las semillas de Ebenopsis caesalpinioides, una leguminosa infrautilizada de Sinaloa, México. En estas semillas se registró: alto contenido de sustancias lipofílicas (triterpenos/esteroles y ácidos grasos); los principales componentes nutricionales fueron lípidos (274 g/kg b.h.), proteínas (271,5 g/kg b.h.), fibra dietaria (127,8 g/kg % b.h.), α-tocoferol (75,8 mg/kg), cobre (12,7 mg/kg), magnesio (2531 mg/kg), manganeso (7,7 mg/kg) y potasio (12686,9 g/kg); los ácidos grasos mayoritarios fueron oleico (619 g/kg), linoleico (122,2 g/kg) y palmítico (94,7 g/kg); proteínas con contenido alto de fenilalanina + tirosina (99,7 g/kg) y bajo en aminoácidos azufrados (14,8 g/kg) y lisina (8,3 g/kg); taninos (8,7 g/kg), ácido fítico (3,2 g/kg); y actividad antioxidante (ABTS = 23246,6 μmolET/kg). De acuerdo a sus propiedades, el consumo de semillas de E. caesalpinioides puede proveer beneficios a la salud para la prevención o manejo de enfermedades cardiovasculares.
    CyTA - Journal of Food 01/2012; · 0.50 Impact Factor
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    ABSTRACT: Randia echinocarpa is a native plant from Mexico that produces an edible fruit with several ethnopharmacological uses (e.g. cancer, kidney ailments, and diabetes). Extracts of this fruit have shown antimutagenic activity. In this report, a methanolic extract of R. echinocarpa and a bio-guided chromatographic strategy were used to obtain an hexanic fraction (HF) with strong antimutagenic activity (microsuspension assay with Salmonella typhimurium YG1024) using 1-nitropyrene as mutagen (1-NP, 50 and 100ng/tube). The HF (500ng/tube) showed the highest inhibition percentage of mutagenic activity (PI) (75%, 1-NP 50ng/tube; 84%, 1-NP 100ng/tube). HF chromatography with silica produced HF1 which was further separated to produce the fractions with the highest antimutagenic activities (HF1–1 and HF1–2, PI≥60%). These fractions were chemically characterized by chromatography and gas chromatography–mass spectrometry; among the main components of HF, HF1–1 and HF1–2 were registered linoleic acid, palmitic acid and β-sitosterol, which could be responsible for the antimutagenic activity of R. echinocarpa fruit. The samples evaluated were neither toxic nor mutagenic. Randia echinocarpa is an underutilized plant and its fruit has been used traditionally as food/medicine; fruit consumption could provide human health benefits and it has potential to be exploited under conditions of ecological sustainability.
    Food Research International. 01/2011; 44(11):3087-3093.
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    ABSTRACT: Gnathostoma turgidum is a gastric nematode parasite of opossums found in the Americas. We recently found that G. turgidum juveniles appear in the liver of the opossums where they become mature adults and almost synchronously move to the stomach during certain months of the year, suggesting the importance of the liver for the growth and maturation of this species in the final hosts. In this study we attempted to detect G. turgidum larvae in the liver of opossums, Didelphis virginiana that are the natural final hosts. The results show that tiny (<3mm in length) third stage larvae (L3) appeared in the liver of opossums around November and December. Also in the liver, we found large L3 of up to about 10mm in length together with juveniles and mature adults from February to March. In spite of their length, large L3 have 4 rows of hooklets, and their gonads remained undeveloped. Morphological features of the small and large L3 of G. turgidum are described including scanning electron microscope images. The seasonal switching of the several growth stages of G. turgidum from small L3 to adult worms in the liver and eventual migration to the stomach in opossums suggests the unique feature of G. turgidum utilizing the liver as the maturation site.
    Parasitology International 05/2010; 59(3):338-43. · 2.30 Impact Factor
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    ABSTRACT: GSTs are a group of multifunctional enzymes, whose major functions involve catalysis of conjugation of glutathione thiolate anion with a multitude of bi-substrates or transportation of a range of hydrophobic ligands. Helminth GSTs are intimately involved in the scavenging of endogenously/exogenously-derived toxic compounds and xenobiotics. In this study, we identified a novel GST gene of Taenia solium metacestodes (TsMs), which is a causative agent of neurocysticercosis. The 804 bp-long cDNA encoded a 639 bp open reading frame (212 amino acid polypeptide), which exhibited the structural motif and domain organisation characteristic of GST. It formed a strong clade with trematode and insect sigmaGSTs. We designated this cDNA as TsM sigma-like GST (TsMsigmaGST). Native TsMsigmaGST identified through gel filtration combined with compatible immunoproteomics consisted of four isoforms at approximately 25 kDa with different pIs between 8.2 and 8.7. TsMsigmaGST showed an enzyme activity as a homodimer and was specifically expressed in the scolex cytosol. The recombinant TsMsigmaGST expressed in Escherichia coli showed sigma-like activity with 1-chloro-2,4-dinitrobenzene (CDNB). The Vmax and Km for CDNB and glutathione (GSH) were 1.08 and 0.78 micromol/min/mg, and 0.16 and 0.17 mM, respectively. Its optimal activity was observed at pH 8.0 and at 40 degrees C. The enzyme activity was potently inhibited by bromosulfophthalein, and to a lesser extent by rose bengal and triphenyltin chloride. Albendazole and praziquantel non-competitively inhibited both G- and H-sites of the enzyme. To our knowledge this is the first description of the sigma-class GST in cestode parasites. The enzyme might be involved in scavenging of intracellularly generated xenobiotics during homeostatic processes and anthelminthic metabolisms. Revelation of biochemical and biological properties of TsMsigmaGST might allow us to understand pathobiological events inherent to this long-standing parasitic disease, and thus to target therapeutic intervention.
    International journal for parasitology 04/2010; 40(9):1097-106. · 3.39 Impact Factor
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    ABSTRACT: The pulp of the Vitex mollis fruit is edible and traditionally used to treat diarrhoea. The antibacterial activity of this fruit is reported here for the first time. The fruit pulp was extracted with methanol (ME) and the extract was fractionated with solvents. ME and their fractions [hexanic (HF), chloroformic (CF), ethyl acetate (EAF) and aqueous (AqF)] were assayed against human pathogenic bacteria (microdilution test) and their phytochemicals determined (qualitative chemical determinations). The samples (i.e., ME, HE, CF, EAF and AqF) showed antibacterial activity; EAF was the most active, showing such activity against Shigella dysenteriae [minimal inhibitory concentration (MIC)=2 mg/ml]. Phenolics were mainly found in ME and EAF; compounds of this chemical family are well known for their antidiarrhoeal and antimicrobial activities. The reported antibacterial activity and phenolics content of V. mollis fruit could be associated with its use in the treatment of diarrhoea.
    International Journal of Green Pharmacy 01/2010;
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    ABSTRACT: Bromelia pinguin L. is a plant native to Sinaloa, Mexico, where its fruit is used as food or as a phytotherapeutic agent. The fruits of B. pinguin were characterized and they could be considered as a functional food. These fruits show an average weight of 13.7 g and a yellow color of high luminosity (b* = 43.2, L* = 74.5). The values for acidity (4.6%, as citric acid) and pH (3.7) of B. pinguin fruit are similar to those of citrics. The edible portion is characterized by a high content of vitamin C (126 mg/100 g), ash (10.6 g/100 g d.w.), crude fiber (3.4 g/100 g d.w.), calcium (1290 mg/100 g d.w.), magnesium (500 mg/100 g d.w.), manganese (2.95 mg/100 g d.w.) and it is a good source of zinc (2.8 mg/100 g d.w.). Polar fractions extracted from the pulp fruit showed activity against several genera of human pathogenic-bacteria (Staphylococcus, Streptococcus, Enterococcus, Salmonella, Shigella, Escherichia and Pseudomonas).
    Plant Foods for Human Nutrition 07/2009; 64(3):181-7. · 2.36 Impact Factor
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    ABSTRACT: Gnathostoma turgidum is a nematode that parasitizes the stomach of opossums, Didelphis virginiana. Despite its wide distribution in the Americas, its natural life cycle is poorly understood. Recently, we found an endemic area for G. turgidum infection in Sinaloa, Mexico (Diaz-Camacho et al., 2009). Based on sporadic surveys for several years, the prevalence was apparently high in summer and extremely low in winter. To confirm that this is really a seasonal variance, we conducted a longitudinal survey on G. turgidum infection in opossums from November 2007 to November 2008. The results showed amazing seasonal changes in the prevalence, with synchronized migration and maturation of worms in opossums. Between February and March, many juvenile worms, with occasional AL3, were found in the liver, but no worms were found in the stomach. Mature adult worms began to appear in the stomach around April and rapidly increased in number toward July, when all worms resided in the stomach. Then, the worms disappeared almost completely by November. These results suggest that G. turgidum is an annual parasite of the opossum, D. virginiana, in Mexico.
    Journal of Parasitology 04/2009; 95(4):908-12. · 1.32 Impact Factor
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    ABSTRACT: A library of 25-membered chalcones was prepared by parallel synthesis. Substituted acetophenones and benzaldehydes were condensed using the Claisen-Schmidt base-catalyzed aldol condensation. Several chalcones showed in vitro antiparasitic activity against Giardia lamblia. The highest activity observed for the IC(50) values were 12.72, 15.05 and 15.31 microg/mL, respectively; these are potential leads for the development of antigiardial compounds.
    Bioorganic & medicinal chemistry 04/2009; 17(18):6780-5. · 2.82 Impact Factor
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    ABSTRACT: Gnathostomosis, caused by Gnathostoma binucleatum, is a serious public health issue in Mexico. Although 2 other Gnathostoma spp., G. turgidum and G. lamothei, have been found in wild animals, their natural life cycle or their relation to human disease remains unclear. While we were conducting an epidemiological survey on Gnathostoma spp. in Sinaloa State, Mexico, we found an endemic area for G. turgidum in common opossums, Didelphis virginiana, located in Tecualilla, Sinaloa. The species identification was carried out by morphological and molecular biological methods. This is the first record of an endemic area for G. turgidum infection in opossums, D. virginiana, in the Americas.
    Journal of Parasitology 12/2008; 95(3):617-22. · 1.32 Impact Factor
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    ABSTRACT: Gnathostomosis is a typical fish-borne zoonotic parasitosis and is currently a serious public health issue in Mexico. Among several Gnathostoma species present in wild animals in Mexico, Gnathostoma binucleatum is the only proven species responsible for human diseases, and the advanced third stage larvae (AL3) of G. binucleatum have been found in over 20 species of fish in this country. In Sinaloa State, two fish species, Dormitator latifrons and Eleotris picta, were heavily contaminated with G. binucleatum AL3. When we analyzed the relationship between the size of the fish and the density of infection with G. binucleatum AL3, the distribution patterns of AL3 were markedly different between these two fish species. Apparent size-dependent accumulation was observed in E. picta but not in D. latifrons, suggesting that E. picta is a paratenic host whereas D. latifrons is a second intermediate host.
    Parasitology Research 09/2008; 103(6):1421-5. · 2.85 Impact Factor