Evaluación de las ingestas dietéticas y prácticas alimentarias en niños de 6 a 23 meses en una localidad del noreste argentino / Assessment of dietary intakes and feeding practices in children aged 6­23 months in a town in the Northeast region of Argentina

Introducción. Una alimentación complementaria adecuada en cantidad y calidad resulta esencial durante los primeros dos años de vida. El objetivo del estudio fue evaluar la ingesta de nutrientes y prácticas alimentarias en niños de 6 a 23 meses de una localidad del noreste argentino. Población y métodos. Estudio descriptivo transversal (segundo semestre del 2019). Se evaluaron las ingestas de 24 horas mediante recordatorios a los cuidadores de niños de 6 a 23 meses. Los datos se compararon con las ingestas dietéticas de referencia. Las prácticas alimentarias se evaluaron según los indicadores establecidos por la Organización Mundial de la Salud. Resultados. Se evaluaron 138 niños de 6 a 23 meses de edad. La energía y las vitaminas A, D y E presentaron porcentajes medios de adecuación inferiores al 100 % en todas las edades, mientras que las proteínas alcanzaron una adecuación promedio del 142,8 % y el 168,1 % para los niños de 7-12 meses y de 13-23 meses, respectivamente. Los nutrientes que presentaron una proporción considerable de casos con ingestas por debajo del requerimiento promedio estimado en todos los grupos fueron la energía y la vitamina A. En cuanto a los indicadores de prácticas alimentarias, 50,8 % de los lactantes recibió una dieta mínima aceptable. Conclusiones. Existe una alta prevalencia de inadecuación energética y de nutrientes críticos durante la alimentación complementaria en los niños de 6 a 23 meses incluidos en el estudio. Intervenciones nutricionales que promuevan prácticas alimentarias que mejoren la ingesta de micronutrientes serían de suma importancia para su salud actual y futura.

Introduction. An adequate quantity and quality of complementary feeding is essential during the first 2 years of life. The objective of this study was to assess dietary intakes and feeding practices in children aged 6­23 months in a town in the Northeast region of Argentina. Population and methods. Descriptive, cross-sectional study (second semester of 2019). Intakes from 24-hour dietary recall interviews conducted among caregivers of children aged 6­23 months were assessed. Data were compared to dietary reference intakes. Feeding practices were assessed as per the World Health Organization's indicators. Results. A total of 138 children aged 6­23 months were assessed. The mean adequacy ratio of energy and vitamins A, D, and E was below 100% for all ages, whereas the protein adequacy for children aged 7-12 and 13-23 months was 142.8% and 168.1%, respectively. A remarkable number of cases had energy and vitamin A intakes below the estimated average requirement. In relation to feeding practice indicators, 50.8% of infants received a minimum acceptable diet. Conclusions. There is a high prevalence of an inadequate level of energy and critical nutrient intake during complementary feeding of the children aged 6­23 months included in the study. Nutritional interventions that promote feeding practices to improve micronutrient intake would be highly important for children's current and future health.

Assessment of dietary intakes and feeding practices in children aged 6-23 months in a town in the Northeast region of Argentina. / Evaluación de las ingestas dietéticas y prácticas alimentarias en niños de 6 a 23 meses en una localidad del noreste argentino.

INTRODUCTION: An adequate quantity and quality of complementary feeding is essential during the first 2 years of life. The objective of this study was to assess dietary intakes and feeding practices in children aged 6-23 months in a town in the Northeast region of Argentina. POPULATION AND METHODS: Descriptive, crosssectional study (second semester of 2019). Intakes from 24-hour dietary recall interviews conducted among caregivers of children aged 6-23 months were assessed. Data were compared to dietary reference intakes. Feeding practices were assessed as per the World Health Organization's indicators. RESULTS: A total of 138 children aged 6-23 months were assessed. The mean adequacy ratio of energy and vitamins A, D, and E was below 100% for all ages, whereas the protein adequacy for children aged 7-12 and 13-23 months was 142.8% and 168.1%, respectively. A remarkable number of cases had energy and vitamin A intakes below the estimated average requirement. In relation to feeding practice indicators, 50.8% of infants received a minimum acceptable diet. CONCLUSIONS: There is a high prevalence of an inadequate level of energy and critical nutrient intake during complementary feeding of the children aged 6-23 months included in the study. Nutritional interventions that promote feeding practices to improve micronutrient intake would be highly important for children's current and future health.

Introducción. Una alimentación complementaria adecuada en cantidad y calidad resulta esencial durante los primeros dos años de vida. El objetivo del estudio fue evaluar la ingesta de nutrientes y prácticas alimentarias en niños de 6 a 23 meses de una localidad del noreste argentino. Población y métodos. Estudio descriptivo transversal (segundo semestre del 2019). Se evaluaron las ingestas de 24 horas mediante recordatorios a los cuidadores de niños de 6 a 23 meses. Los datos se compararon con las ingestas dietéticas de referencia. Las prácticas alimentarias se evaluaron según los indicadores establecidos por la Organización Mundial de la Salud. Resultados. Se evaluaron 138 niños de 6 a 23 meses de edad. La energía y las vitaminas A, D y E presentaron porcentajes medios de adecuación inferiores al 100 % en todas las edades, mientras que las proteínas alcanzaron una adecuación promedio del 142,8 % y el 168,1 % para los niños de 7-12 meses y de 13-23 meses, respectivamente. Los nutrientes que presentaron una proporción considerable de casos con ingestas por debajo del requerimiento promedio estimado en todos los grupos fueron la energía y la vitamina A. En cuanto a los indicadores de prácticas alimentarias, 50,8 % de los lactantes recibió una dieta mínima aceptable. Conclusiones. Existe una alta prevalencia de inadecuación energética y de nutrientes críticos durante la alimentación complementaria en los niños de 6 a 23 meses incluidos en el estudio. Intervenciones nutricionales que promuevan prácticas alimentarias que mejoren la ingesta de micronutrientes serían de suma importancia para su salud actual y futura.

Análisis del consumo, utilización y aprovechamiento de frutas y verduras entre los años 2019 y 2021 / Analysis of consumption, use and utilization of fruits and vegetables between 2019 and 2021

En 2021 se conmemoró el Año Internacional de las Frutas y Verduras (FyV). Estos alimentos cumplen un rol indispensable en la dieta, sin embargo, un amplio sector de la población no las consume en la variedad y cantidad recomendadas. A esto se suma la problemática de las pérdidas y desperdicios de alimentos, situación que trae consigo un impacto negativo a nivel social, ambiental y económico. El objetivo del presente artículo fue analizar el consumo, utilización y aprovechamiento de FyV desde las perspectivas de salud y sostenibilidad. Para esto, se realizaron cuatro encuestas entre 2019 y 2021 que evaluaron diferentes dimensiones relacionadas con estos alimentos: adecuación del consumo, variedades consumidas, criterios de calidad de FyV apreciados por los consumidores y prácticas de sostenibilidad y consumo responsable. Sólo el 19% de los encuestados presentó consumos adecuados de FyV (5 o más porciones diarias). La variedad de frutas consumidas es menor que la de hortalizas, concentrándose en tres de ellas: manzana, banana y naranja. Los principales factores identificados como limitantes del consumo de FyV fueron el precio, la elevada perecibilidad de estos alimentos y la preferencia hacia otros productos. En relación a las prácticas de alimentación sostenible y los principales criterios de calidad valorados por los consumidores se observó un bajo aprovechamiento de partes comestibles de frutas o verduras, menos del 27% de los encuestados consume la fruta con cáscara, y un mayor desaprovechamiento de partes comestibles de verduras, dónde el 64% de los encuestados tira partes como tallos u hojas, aún cuando existen vías de aprovechamiento con fines no alimenticios. Por último, el factor de calidad más apreciado por los consumidores es la apariencia (30%), el valor nutricional no fue un parámetro de gran valoración (6%)(AU).

In 2021, the International Year of Fruits and Vegetables (FyV) was commemorated. These foods play an essential role in the diet; however, a large sector of the population does not consume them in the recommended variety and quantity. Added to this is the problem of food losses and waste, a situation that brings about a negative impact at a social, environmental and economic level. The objective of this article was to analyze the consumption, use and utilization of F&V from the perspectives of health and sustainability. For achiving this, four surveys were carried out between 2019 and 2021 that evaluated different dimensions: adequacy of consumption, varieties consumed, F&V quality criteria appreciated by consumers, and sustainability practices and responsible consumption. Only 19% of those surveyed presented adequate consumption of F&V (5 or more daily servings). The variety of fruits consumed is less than that of vegetables, concentrating on three of them: apple, banana and orange. The main factors limiting the consumption of F&V were the price, the high perishability of these foods and the preference for other products. In relation to sustainable eating practices and the main quality criteria valued by consumers, a low use of edible parts of fruits or vegetables was observed, less than 27% of respondents consume fruit with peel, and a greater waste of edible parts of vegetables, where 64% of respondents throw away parts such as stems or leaves, even when there are ways of using them for non-food purposes. Finally, the quality factor most appreciated by consumers is appearance (30%), nutritional value was not a highly valued parameter (6%)(AU).

Pharmacological Activity of Quercetin and 5 Caffeoylquinic Acid Oral Intake in Male Balb/c Mice with Lung Adenocarcinoma.

BACKGROUND: Lung adenocarcinoma (LAC) is a major worldwide cause of death by cancer, it shows high aggressiveness, functional decline, systemic compromise and severe cachexia, which might be counteracted by dietary redox-active phytochemicals. Therefore, our aim was to establish the anticancer effects of the oral intake of quercetin and 5 caffeoylquinic acid. METHODS: LAC-1-bearing male Balb/c mice received quercetin (0-25 µg/kg/d) and 5 caffeoylquinic acid (0-120 µg/kg/d) for three weeks, with different organic and biochemical variables being then compared with ANOVA and the Fisher Test (p <0.05). RESULTS: Quercetin delayed 1.18 fold tumour appearance and increased 8.87 fold non-neoplastic body weight gain, whereas 5 caffeoylquinic acid did it in a lesser extent (1.17 and 2.48 fold, respectively), with tumour weight being consequent with the evolution time. Quercetin induced >1.15 fold tumour hydroperoxides and lipoperoxides, whereas 5 caffeoylquinic acid induced only lipoperoxides. Although both phytochemicals reduced <0.85 fold hydroperoxides and lipoperoxides in the kidney, only quercetin was also antioxidant in the liver. Additionally, 5 caffeoylquinic acid increased >1.15 fold hepatic and renal weights. Although these phytochemicals did not modify telencephalic interleukin 6 production, quercetin augmented 2.51 fold interleukin 6 in the diencephalon, whereas 5 caffeoylquinic acid decreased it 0.43 fold. CONCLUSIONS: Quercetin delayed lung adenocarcinoma appearance and increased the non-neoplastic body weight gain in mice with tumour oxidative stress, without brain interleukin 6 participation. 5 caffeoylquinic acid showed similar effects, although they were weaker. Additionally, quercetin acted as a hepatic and renal antioxidant, whereas 5 caffeoylquinic acid only exerted this effect in the kidney. Therefore, safe oral doses of this flavonoid are promissory to modulate lung cancer progression, with further studies being encouraged.

Effects of bioavailable phenolic compounds from Ilex paraguariensis on the brain of mice with lung adenocarcinoma.

Lung carcinoma is one of the most common cancers and has a high mortality. Recently, we showed that it produces neurological paraneoplastic syndrome, with Ilex paraguariensis (IP) extract exerting palliative effects due to its content of phenolic compounds. It is possible, therefore, that these diet agents can arrive at the brain and exert neuroprotection, after the oral intake of IP. Here, the aim was to investigate the protective role of bioavailable IP compounds on the telencephalon and diencephalon in lung adenocarcinoma-bearing BALB/cJ males. Mice aged 2 months were treated for 3 weeks with 0-100 IP mg·kg-1 ·day-1 . HPLC-UV revealed the presence of chlorogenic acid and quercetin in brain regions, liver, and tumour, in an IP dose-dependent manner. Brain was also evaluated histologically, and interleukin-6 was measured by ELISA. Chlorogenic acid was the major compound found in brain, whereas quercetin was observed at the diencephalon to a lesser extent. Both compounds were involved in IP dose-dependent diencephalic interleukin-6 reduction. Histology suggested cellular protection with less apoptosis in chlorogenic-exposed areas. Taken together, chlorogenic acid and quercetin from dietary IP were bioavailable and bioactive in brain, thereby attenuating lung cancer-related neuroinflammation and damage. These findings support plant-based strategies to improve prognosis.

Neuroprotective Effect of Ilex Paraguariensis Intake on Brain Myelin of Lung Adenocarcinoma-Bearing Male Balb/c Mice.

Ilex paraguariensis (IP) is widely consumed as tea with high nutritional value. This plant contains several bioactive phenolic compounds, which are antioxidant and anti-inflammatory. On the other hand, lung adenocarcinoma (LAC) deleteriously involves neoplastic progression, inflammatory paraneoplastic syndromes, and death. Given that brain is a frequent target of this illness, our objective was to determine the neuroprotective effect of IP consumption in LAC-bearing mice. They were orally treated with 50 mg of IP extract/kg/day (IP50) for 3 weeks. Results (phenolic compounds, lipid peroxides, interleukin 6-IL-6-, tumor necrosis factor alpha -TNFα-, and luxol-stained myelination) were compared with respect to untreated controls (C) by the T test. IP50 significantly lowed brain IL-6 (2858.12 ± 57.81 pg g-1 vs. 3801.30 ± 27.34 pg g-1), whereas other variables differed in a less extent. C brains showed demyelination (low luxol-staining contrast between gray and white matters), with IP50 increasing myelination (P < 0.05). In conclusion, LAC deleterious effects on murine brain were prevented by dietary IP, which is an original discovery to develop a nutritional approach against cancer neurological compromise.

Pharmacology and Toxicology of Polyphenols with Potential As Neurotropic Agents in Non-communicable Diseases.

BACKGROUND: The central nervous system (CNS) is involved in organic integration. Nervous modulation via bioactive compounds can modify metabolism in order to prevent systemic noncommunicable diseases (NCDs). Concerning this, plant polyphenols are proposed as neurotropic chemopreventive/ therapeutic agents, given their redox and regulating properties. OBJECTIVE: To review polyphenolic pharmacology and potential neurological impact on NCDs. METHOD: First, polyphenolic chemistry was presented, as well as pharmacology, i.e. kinetics and dynamics. Toxicology was particularly described. Then, functional relevance of these compounds was reviewed focusing on the metabolic CNS participation to modulate NCDs, with data being finally integrated. RESULTS: Oxidative stress is a major risk factor for NCDs. Polyphenols regulate the redox biology of different organic systems including the CNS, which participates in metabolic homeostasis. Polyphenolic neurotropism is determined by certain pharmacological characteristics, modifying nervous and systemic physiopathology, acting on several biological targets. Nonetheless, because these phytochemicals can trigger toxic effects, they should not be recommended indiscriminately. CONCLUSION: Summing up, the modulating effects of polyphenols allow for the physiological role of CNS on metabolism and organic integration to be utilized in order to prevent NCDs, without losing sight of the risks.

[Modifications of the superoxide anion level in breast milk by the intake of flavonoids and carotenoids]. / Modificaciones en el nivel de anión superóxido en leche materna, según la ingesta de flavonoides y carotenoides.

OBJECTIVE: To associate the intake of flavonoids and carotenoids with the breast milk level of superoxide anion, as an oxidative stress marker. MATERIALS AND METHODS: 100 women from Cordoba (Argentina), who breastfed within the first postpartum 6 months, were studied during the 2013-2015 period, by evaluating their sanitary data, food intake and anion level in milk with multiple logistic regression. RESULTS: The intake of flavonoids, provitamin A carotenoids and non-provitamin carotenoids was 72 (61) mg/d, 1813 (1 657) µg/d y 5427 (3 664) µg/d, respectively. The anion was associated with the intake of flavanols (OR=1.081; CI95 1.001-1.167) y flavanones (OR=1.025; CI95 1.001-1.048). This effect was not seen with other flavonoids and carotenoids. CONCLUSIONS: Intake of flavanols and flavanones increases milk oxidation risk, which is relevant to develop diet recommendations.

OBJETIVO: Asociar la ingesta de flavonoides y carotenoides con el nivel en leche materna del anión superóxido, como marcador de estrés oxidativo. MATERIAL Y MÉTODOS: Durante el periodo 2013-2015 se estudió a 100 mujeres lactantes de Córdoba (Argentina), dentro los primeros seis meses posparto; se evaluaron sus datos sanitarios, ingesta alimentaria y nivel lácteo del anión con regresión logística múltiple. RESULTADOS: La ingesta de flavonoides, carotenoides provitamínicos y carotenoides no provitaminas fue de 72 (61) mg/día, 1 813 (1657) µg/día y 5 427 (3664) µg/día, respectivamente. El anión se asoció con la ingesta de flavanoles (RM=1.081; IC95 1.001-1.167) y flavanonas (RM=1.025; IC95 1.001-1.048). No se observó este efecto con otros flavonoides ni con los carotenoides. CONCLUSIONES: La ingesta de flavanoles y flavanonas aumenta el riesgo de oxidación láctea, lo cual es relevante para realizar recomendaciones dietéticas.

Modificaciones en el nivel de anión superóxido en leche materna, según la ingesta de flavonoides y carotenoides / Modifications of the superoxide anion level in breast milk by the intake of flavonoids and carotenoids

Resumen: Objetivo: Asociar la ingesta de flavonoides y carotenoides con el nivel en leche materna del anión superóxido, como marcador de estrés oxidativo. Material y métodos: Durante el periodo 2013-2015 se estudió a 100 mujeres lactantes de Córdoba (Argentina), dentro los primeros seis meses posparto; se evaluaron sus datos sanitarios, ingesta alimentaria y nivel lácteo del anión con regresión logística múltiple. Resultados: La ingesta de flavonoides, carotenoides provitamínicos y carotenoides no provitaminas fue de 72 (61) mg/día, 1 813 (1657) µg/día y 5 427 (3664) µg/día, respectivamente. El anión se asoció con la ingesta de flavanoles (RM=1.081; IC95 1.001-1.167) y flavanonas (RM=1.025; IC95 1.001-1.048). No se observó este efecto con otros flavonoides ni con los carotenoides. Conclusiones: La ingesta de flavanoles y flavanonas aumenta el riesgo de oxidación láctea, lo cual es relevante para realizar recomendaciones dietéticas.

Abstract: Objective: To associate the intake of flavonoids and carotenoids with the breast milk level of superoxide anion, as an oxidative stress marker. Materials and methods: 100 women from Cordoba (Argentina), who breastfed within the first postpartum 6 months, were studied during the 2013-2015 period, by evaluating their sanitary data, food intake and anion level in milk with multiple logistic regression. Results: The intake of flavonoids, provitamin A carotenoids and non-provitamin carotenoids was 72 (61) mg/d, 1813 (1 657) µg/d y 5427 (3 664) µg/d, respectively. The anion was associated with the intake of flavanols (OR=1.081; CI95 1.001-1.167) y flavanones (OR=1.025; CI95 1.001-1.048). This effect was not seen with other flavonoids and carotenoids. Conclusions: Intake of flavanols and flavanones increases milk oxidation risk, which is relevant to develop diet recommendations.

[Regional oxidative stress in encephalon of female mice with polyphenolic exposure from tea extracts in oral overweight plant-based treatment].

Polyphenols provide by diet may act as antioxidant in the Central Nervous System and exert a protective effect on metabolic diseases. The aim of this study was to establish tea extract effects on oxidative status and murine overweight in accordance with polyphenolic availability in different encephalic regions. METHODS: Balb/c mice (female, n>3) with overweight received for 15 days 100 mg/Kg/d of extract from Lantana grisebachii, Aspidosperma quebracho-blanco, or Ilex paraguariensis extracts and control group (received water without extract). Body weight gain was recorded regularly. Polyphenols, hydroperoxides (HP), lipid peroxides (LP), and superoxide anion (SO) were measured in brain (telencephalon and diencephalon), midbrain, brainstem and cerebellum. Results were compared by ANOVA followed by the Tukey test (P<0.05). RESULTS: A. quebracho-blanco-based treatment decreased weight gain and increased polyphenols in brainstem (p<0.02), although it concomitantly increased SO and LP in this region (p=0.0029 and p=0.0280, respectively). L. grisebachii-based treatment reduced oxidative markers differentially in each region (p<0.05). I. paraguariensis-based treatment oxidized midbrain and cerebellum, although it was antioxidant in the brainstem (p<0.05). All treatments were antioxidant in telencephalon (p=0.0029). CONCLUSIONS: The A. quebracho-blanco extract was active on overweight and increased polyphenols in brainstem, with safe functional derivatives being required to avoid oxidative stress. Other extracts affected oxidative status in a region-dependent manner.

[Bioavailability of phenolic compounds and redox state of murine liver and kidney as sex-dependent responses to phytoextracts.]

BACKGROUND: Plant extracts can be obtained to carry bioactive compounds, useful for prevention and treatment of different illnesses. This also supports the intake of teas as functional beverages. Nonetheless, it is incompletely known whether these extracts can act as effective sources and vehicles de phenolic compounds (phenolics/polyphenols) to reach their targets. OBJECTIVE: To establish whether phytoextract ingestion modified in a sex-dependent manner the phenolic bioavailability and redox response in liver and kidney. METHOD: BALB/C mice ingested for a month 100 mg/Kg/d of extracts (tea-like) from Aspidosperma quebracho-blanco (AQB), Lantana grisebachii (LG) or Ilex paraguariensis (IP). Then, phenolics, peroxides and nitrites were analyzed by spectrophotometry. Also, phenolic permeation from digested and undigested extracts was evaluated in vitro with a rat jejunum-based assay. RESULTS: Phenolic permeation depended on extract digestion. In males, IP showed a special time course of hepatic phenolics, whereas all extracts decreased renal phenolics at 15 days. Extracts induced hepatic lipoperoxides at 15 days. LG reduced renal hydroperoxides at 15 days and hepatic nitrites at 30 days, whereas AQB and IP reduced renal lipoperoxides and nitrites at 30 days. In females, extracts reduced hydroperoxides, with LG and AQB also reducing lipoperoxides. IP increased renal lipoperoxides at 30 days. CONCLUSION: IP was a relevant phenolic source. Sex-dependent responses were found in all variables, which should be considered to prevent misleading generalizations in phytodrug bioprospecting.

Development of an Antioxidant Phytoextract of Lantana grisebachii with Lymphoprotective Activity against In Vitro Arsenic Toxicity.

Phytochemicals have been presumed to possess prophylactic and curative properties in several pathologies, such as arsenic- (As-) induced immunosuppression. Our aim was to discover a lymphoprotective extract from Lantana grisebachii Stuck. (Verbenaceae) (LG). We assessed its bioactivity and chemical composition using cell-based assays. Fractions produced from a hexane extract acutely induced nitrite formation in T-activated cell cultures (P < 0.0001). Water extraction released a fraction lacking nitrite inducing activity in both lymphocyte types. Aqueous LG was found to be safe in proliferated and proliferating cells. The infusion-derived extract presented better antioxidant capacity in proportion to phenolic amount in lymphocytes (infusive LG-1i at 100 µ g/mL), which protected them against in vitro As-induced lymphotoxicity (P < 0.0001). This infusive LG phytoextract contained 10.23 ± 0.43 mg/g of phenolics, with 58.46% being flavonoids. Among the phenolics, the only predominant compound was 0.723 mg of chlorogenic acid per gram of dry plant, in addition to 10 unknown minor compounds. A fatty acid profile was assessed. It contained one-third of saturated fatty acids, one-third of ω 9, followed by ω 6 (~24%) and ω 3 (~4%), and scarce ω 7. Summing up, L. grisebachii was a source of bioactive and lymphoprotective compounds, which could counteract As-toxicity. This supports its phytomedical use and research in order to reduce As-related dysfunctions.

Aplicación de componentes alimentarios en problemas de salud asociados a estrés oxidativo: selección de compuestos con propiedades antiradicalarias a partir de almentos o productos alimenticios regionales / Application of food components on health problems associated with oxidative stress: selection of compounds with properties Antiradical from almentos or regional food

El Síndrome Urémico Hemolítico (SUH) mediado por Escherichia coli productora de Verotoxinas es la causa más común de falla renal aguda en niños menores de 5 años y Argentina es el país con mayor incidencia de este síndrome. El serotipo O157:H7 es el que se asocia con mayor frecuencia y gravedad a infecciones humanas. Esta bacteria secreta diferentes factores de virulencia (FV) dentro del los cuales Verotoxina (VT) es el más importante. VT llega al torrente circulatorio y además de ejercer su efecto citotóxico por inhibición de la síntesis proteica con la consiguiente apoptosis de las células blanco, actúa estimulando los leucocitos polimorfonucleares y promoviendo la producción de Especies Reactivas del Oxígeno (ERO) por un mecanismo que aún no se encuentra esclarecido, sin embargo se ha postulado que el estrés oxidativo (EO) está involucrado en la acción de las principales toxinas de E.coli verotoxigénico. Por este motivo fue objeto de esta tesis doctoral evaluar el efecto de los factores de virulencia de E.coli O157:H7 sobre: promotores de EO (ERO y Especies Reactivas del Nitrógeno- ERN), marcadores de oxidación de moléculas lipídicas y proteicas y la capacidad antioxidante total (CA) en sangre de personas sanas y pacientes con SUH, como así también la obtención de antioxidantes exógenos de origen vegetal que permitan contrarrestar los efectos dañinos del EO, neutralizar la acción citotóxica de VT y/ó disminuir su producción- liberación por parte de la bacteria

SUMMARY: Hemolytic Uremic Syndrome (HUS) mediated by Escherichia coli producing shigatoxins (Stxs) is denominated E. coli STEC, and is the most common cause of acute renal failure in children under 5 years old and Argentina has the highest incidence of this syndrome. The serotype O157: H7 is the one associated with more frequent and severe human infections. This bacterium secretes several virulence factors within which Stx or verotoxin is the most important. Stx reached the general circulation and also to exert its cytotoxic effect by inhibiting protein synthesis with subsequent apoptosis of target cells, like leukocytes. This toxin works by stimulating and promoting the production of reactive oxygen species (ROS) by a mechanism not yet clarified, however it has been postulated that oxidative stress is involved in the action of this major toxin of E. coli STEC. For this reason was the objective of this thesis to evaluate the effect of the virulence factors of E. coli serotype O157: H7 on the promoters of oxidative stress (ROS and reactive nitrogen species RNS), markers of lipid and protein oxidation. Total antioxidant capacity assayed by ferric reducing antioxidant power (FRAP) method was investigated in blood of healthy individuals and patients with HUS. Plant extracts were studied as antioxidants to counteract the harmful effects of oxidative stress. The extracts were obtained from carob flour (Prosopis alba) and mistol (Ziziphus mistol) by maceration with different solvents (acetone, hexane, alcohol and water) which underwent a characterization of their chemical composition by spectrophotometric analysis and thin layer chromatography (TLC). From these trials were selected alcoholic and acetone extracts of both fruit because presented the best relation dissolved solids/functional groups

Aplicación de componentes alimentarios en problemas de salud asociados a estrés oxidativo: selección de compuestos con propiedades antiradicalarias a partir de almentos o productos alimenticios regionales / Application of food components on health problems associated with oxidative stress: selection of compounds with properties Antiradical from almentos or regional food

El Síndrome Urémico Hemolítico (SUH) mediado por Escherichia coli productora de Verotoxinas es la causa más común de falla renal aguda en niños menores de 5 años y Argentina es el país con mayor incidencia de este síndrome. El serotipo O157:H7 es el que se asocia con mayor frecuencia y gravedad a infecciones humanas. Esta bacteria secreta diferentes factores de virulencia (FV) dentro del los cuales Verotoxina (VT) es el más importante. VT llega al torrente circulatorio y además de ejercer su efecto citotóxico por inhibición de la síntesis proteica con la consiguiente apoptosis de las células blanco, actúa estimulando los leucocitos polimorfonucleares y promoviendo la producción de Especies Reactivas del Oxígeno (ERO) por un mecanismo que aún no se encuentra esclarecido, sin embargo se ha postulado que el estrés oxidativo (EO) está involucrado en la acción de las principales toxinas de E.coli verotoxigénico. Por este motivo fue objeto de esta tesis doctoral evaluar el efecto de los factores de virulencia de E.coli O157:H7 sobre: promotores de EO (ERO y Especies Reactivas del Nitrógeno- ERN), marcadores de oxidación de moléculas lipídicas y proteicas y la capacidad antioxidante total (CA) en sangre de personas sanas y pacientes con SUH, como así también la obtención de antioxidantes exógenos de origen vegetal que permitan contrarrestar los efectos dañinos del EO, neutralizar la acción citotóxica de VT y/ó disminuir su producción- liberación por parte de la bacteria(AU)

SUMMARY: Hemolytic Uremic Syndrome (HUS) mediated by Escherichia coli producing shigatoxins (Stxs) is denominated E. coli STEC, and is the most common cause of acute renal failure in children under 5 years old and Argentina has the highest incidence of this syndrome. The serotype O157: H7 is the one associated with more frequent and severe human infections. This bacterium secretes several virulence factors within which Stx or verotoxin is the most important. Stx reached the general circulation and also to exert its cytotoxic effect by inhibiting protein synthesis with subsequent apoptosis of target cells, like leukocytes. This toxin works by stimulating and promoting the production of reactive oxygen species (ROS) by a mechanism not yet clarified, however it has been postulated that oxidative stress is involved in the action of this major toxin of E. coli STEC. For this reason was the objective of this thesis to evaluate the effect of the virulence factors of E. coli serotype O157: H7 on the promoters of oxidative stress (ROS and reactive nitrogen species RNS), markers of lipid and protein oxidation. Total antioxidant capacity assayed by ferric reducing antioxidant power (FRAP) method was investigated in blood of healthy individuals and patients with HUS. Plant extracts were studied as antioxidants to counteract the harmful effects of oxidative stress. The extracts were obtained from carob flour (Prosopis alba) and mistol (Ziziphus mistol) by maceration with different solvents (acetone, hexane, alcohol and water) which underwent a characterization of their chemical composition by spectrophotometric analysis and thin layer chromatography (TLC). From these trials were selected alcoholic and acetone extracts of both fruit because presented the best relation dissolved solids/functional groups(AU)

Chemiluminescence determination of antioxidant property of Zizyphus mistol and Prosopis alba during oxidative stress generated in blood by Hemolytic Uremic Syndrome-producing Escherichia coli.

This study was undertaken to elucidate the antioxidant effect of Zizyphus mistol and Prosopis alba, with the hypothesis that these fruits can counteract the induction of reactive oxygen species (ROS) caused by toxins produced by Escherichia coli. In the search of nutrients effective against the Hemolytic Uremic Syndrome (HUS), we detected by chemiluminescence a protective role of both plants, due to their natural antioxidants significantly decreasing the levels of ROS induced by toxins from E. coli in blood. The ferric reducing antioxidant power (FRAP) was found to be higher in Z. mistol than in P. alba. The chemical analyses of the phenols and flavonoids present in the fruit extracts indicated that the FRAP correlated with the amount of phenolic compounds, but not with the flavonoids analyzed. Both fruits studied reduce the induction of ROS, and in this way help to prevent the development of complications related to oxidative stress generated in the blood of patients with HUS.

Beneficial effect of Berberis buxifolia Lam, Ziziphus mistol Griseb and Prosopis alba extracts on oxidative stress induced by chloramphenicol.

The chemiluminescence of luminol, a measure of oxidative stress, increased immediately as a consequence of reactive oxygen species (ROS) stimulated by this antibiotic. The effect of Ch was dose dependent with maximum stimulus at 8 mg/ml (Vmax); above this concentration the cells began to reduce the production of ROS. The oxidative injury of Ch was counteracted by water extracts of Berberis buxifolia lam, Zizyphus mistol Griseb and Prosopis alba, indigenous fruits from Argentina. The relatively light units (RLU) emitted decreased immediately as a consequence of a protective effect exerted by the extracts of these fruit extracts on blood cells. The three indigenous fruit extracts reduced to a different extent the oxidative injury caused by Ch. B.buxifolia lam exhibited the highest antioxidant capacity followed by Z.mistol Griseb. Water extracts of both fruit extracts were the most effective against the oxidative stress, while P.alba presented better antioxidant capacity in the ethanolic fraction obtained. Hexane extracts showed low protective action on blood cells, with little reduction of area under curve (AUC) of RLU plotted versus time. Leukocytes remained viable in blood samples incubated for 3h with Ch and water extracts of B. buxifolia lam or Z. mistol Griseb (97.1% and 92.5% viability by Trypan blue exclusion, respectively); whereas with Ch only the cells were stressed and viability decreased to 30%. The three fruit extracts protected the viability of leukocytes in parallel with the decrease of ROS. Erythrocytes were not lysed in the presence of Ch.

Beneficial effect of Berberis buxifolia Lam, Ziziphus mistol Griseb and Prosopis alba extracts on oxidative stress induced by chloramphenicol / Efecto benéfico de extractos de Berberis buxifolia Lam, Zizyphus mistol Griseb y Prosopis alba sobre el estrés oxidativo inducido por cloramfenicol

The chemiluminescence of luminol, a measure of oxidative stress, increased immediately as a consequence of reactive oxygen species (ROS) stimulated by this antibiotic. The effect of Ch was dose dependent with maximum stimulus at 8 mg/ml (Vmax); above this concentration the cells began to reduce the production of ROS. The oxidative injury of Ch was counteracted by water extracts of Berberis buxifolia lam, Zizyphus mistol Griseb and Prosopis alba, indigenous fruits from Argentina. The relatively light units (RLU) emitted decreased immediately as a consequence of a protective effect exerted by the extracts of these fruit extracts on blood cells. The three indigenous fruit extracts reduced to a different extent the oxidative injury caused by Ch. B.buxifolia lam exhibited the highest antioxidant capacity followed by Z.mistol Griseb. Water extracts of both fruit extracts were the most effective against the oxidative stress, while P.alba presented better antioxidant capacity in the ethanolic fraction obtained. Hexane extracts showed low protective action on blood cells, with little reduction of area under curve (AUC) of RLU plotted versus time. Leukocytes remained viable in blood samples incubated for 3h with Ch and water extracts of B. buxifolia lam or Z. mistol Griseb (97.1% and 92.5% viability by Trypan blue exclusion, respectively); whereas with Ch only the cells were stressed and viability decreased to 30%. The three fruit extracts protected the viability of leukocytes in parallel with the decrease of ROS. Erythrocytes were not lysed in the presence of Ch.

Se estudió el efecto antioxidante de tres extractos de frutas autóctonas, Berberis buxifolia lam (michay), Zizyphus mistol Griseb (mistol) and Prosopis alba (algarrobo). Las células sanguíneas humanas sufrieron estrés oxidativo por acción de cloramfenicol (Ch), con un aumento inmediato de especies reactivas del oxígeno (ERO), que fue determinado por quimioluminiscencia con luminol. La respuesta fue dependiente de la dosis, con un máximo a 8 mg/ml. Los extractos de frutas autóctonas de la Argentina fueron capaces de contrarrestar el estrés generado por el antibiótico. El michay y el mistol resultaron más efectivos en la fase acuosa, y el algarrobo fue más antioxidante en extractos etílicos, mientras que las fracciones obtenidas con hexano no fueron activas. La viabilidad de los leucocitos se mantuvo elevada con Ch en presencia de extractos, entre 92.5 y 97.1%, cayendo hasta un 30% con Ch solo. Tanto los eritrocitos como los leucocitos fueron protegidos del efecto estresante por la capacidad antioxidantes de los extractos de las tres frutas investigadas, lo que podría ser importante a considerar en la dieta de niños, y pacientes en general, sometidos a Ch u otras terapias causantes de estrés oxidativo.