Radicales libres y sistema antioxidante

Los radicales libres son compuestos caracterizados por tener un electrón desapareado en su orbital externo, condición que los torna altamente reactivos, es decir, tienen la propiedad de interactuar a través de reacciones controladas por difusión con proteínas, lípidos y ácidos nucleicos. También se les ha designado como especies reactivas de oxígeno (ERO), especies reactivas de nitrógeno (ERN) o especies reactivas de azufre (ERA). En el organismo humano se generan, principalmente, en la cadena transportadora de electrones mitocondrial, donde específicamente participan los complejos respiratorios I y III que tienen la propiedad de reducir al oxígeno y convertirlo en anión superóxido; así mismo, pueden formarse haciendo uso de una gran diversidad de reacciones enzimáticas y no enzimáticas en las que intervienen sustancias que la célula sintetiza o que se ingieren con los alimentos y algunos medicamentos. El ser humano dispone de un sistema antioxidante, que es de naturaleza enzimática y no enzimática, el cual tiene como función proteger al organismo de la acción nociva de los radicales libres; comprende enzimas -como catalasa, superóxido dismutasa, tiorredoxina, etc.- y compuestos no enzimáticos -como glutatión, ferritina, mioglobina, etc.-, pero no son lo suficientemente eficientes para protegerlo, por lo que es necesaria la ingesta de alimentos que contengan en su composición sustancias con propiedades antioxidantes cuya acción protectora dependerá de su reactividad química, así como de su concentración; estos compuestos antioxidantes se encuentran principalmente en las frutas y verduras, habiéndose identificado polifenoles, flavonoides, carotenoides, vitamina C, vitamina E, etc. Un número considerable de evidencias sugiere que la ingesta de sustancias antioxidantes protege al organismo del efecto dañino de los radicales libres, pero cuando prevalece la acción oxidante sobre la antioxidante puede conducirse al estrés oxidativo, condición que está estrechamente vinculada con una gran diversidad de enfermedades crónicas no transmisibles como cáncer, diabetes mellitus, obesidad, psoriasis, aterosclerosis, entre otras. Todo ello parece indicar que el término "estado estable redox celular" describe de manera apropiada la constante adaptación a una situación de rápido recambio químico, y sugiere que las sustancias implicadas en este proceso se designen como "especies biológicamente reactivas" en razón de la existencia de compuestos nocivos como el peróxido de hidrógeno, peroxinitrito, etc., que no son propiamente radicales libres, pero ejercen efectos dañinos a las células.

Free radicals are compounds characterized by having an unpaired electron in their outer orbit, a condition that makes them highly reactive, i.e., they interact through diffusion-controlled reactions with proteins, lipids and nucleic acids. They have also been referred to as reactive oxygen species (ROS), reactive nitrogen species (RNS) or reactive sulfur species (RSS). In the human organism, they are mainly produced in the mitochondrial electron transport chain, where respiratory complexes I and III specifically participate and reduce oxygen by converting it into superoxide anion. Likewise, they can be formed through a wide variety of enzymatic and non-enzymatic reactions involving substances that are synthesized by cells or are ingested with food and some medicines. Human beings have an antioxidant system which is both enzymatic and non-enzymatic in nature and whose function is to protect the organism from the harmful action of free radicals. This system includes enzymes-such as catalase, superoxide dismutase, thioredoxin, etc.-and non-enzymatic compounds- such as glutathione, ferritin, myoglobin, etc. However, they are not efficient enough to protect it, so it is necessary to eat foods that contain substances with antioxidant properties whose protective action will depend on their chemical reactivity and their concentration. These antioxidant compounds are mainly found in fruits and vegetables, where polyphenols, flavonoids, carotenoids, vitamin C, vitamin E, etc. have been identified. A significant amount of evidence suggests that the intake of antioxidant substances protects the body from the damaging effect of free radicals, but when the oxidative action prevails over the antioxidant action, it can lead to oxidative stress, a condition that is closely linked to a wide variety of chronic non-communicable diseases including cancer, diabetes mellitus, obesity, psoriasis, atherosclerosis, among others. All this seems to indicate that the term "cellular redox steady state" more appropriately describes the constant adaptation to a situation of rapid chemical turnover and suggests that the substances involved in this process be designated as "biologically reactive species" due to the existence of harmful compounds such as hydrogen peroxide, peroxynitrite, etc., which are not-strictly speaking-free radicals but have toxic effects on cells.

Actividad antioxidante del fruto de Rubus sparsiflorus (Shiraca) / Antioxidant activity of the fruit of Rubus sparsiflorus (Shiraca)

Objetivo: Determinar la actividad antioxidante del fruto de Rubus sparsiflorus (shiraca). Material y métodos: Se preparó un homogenizado con agua destilada y se centrifugó a 15,000 rpm por 10 minutos, el sobrenadante se utilizó para realizar las determinaciones analíticas. Los polifenoles se determinaron con la técnica de Singleton y Rossi, los flavonoides con la técnica de Jia, Tang y Wu, la vitamina C con la técnica de Jagota y Dan y las antocianinas con la de Giusti y Wrolstad. Así mismo, se determinó la capacidad antioxidante utilizando las técnicas FRAP (Benzie y Strain), DPPH (Brand-Williams, Cuvellier y Berset), ABTS (Rice-Evans, Miller y Paganga) y el sistema ascorbato/cobre (Uchida y Kawakishi).Resultados: La shiraca madura mostró un contenido de polifenoles de 415.4 mg. EAG/100g de fruta, flavonoides 72.03 mg.EC/100g de fruta y antocianinas 147.38 mg de cianidina-3-glucósido/100g de fruta que fueron más elevados que la shiraca verde, en cambio, el contenido de vitamina C fue similar en el fruto maduro (108.35 mg/100g) y el verde (118.52 mg/100g). Así mismo, la actividad antioxidante del fruto maduro evaluada con las técnicas FRAP (8.05 mmoles de Fe-II/100 g de fruta), DPPH (IC50 = 0.76 mg/mL), ABTS (IC50 = 0.147 mg/mL) y el sistema ascorbato/cobre (IC50 = 2.16 mg/mL) mostraron que el fruto maduro tuvo mayor capacidad antioxidante que el fruto verde.Conclusiones: La shiraca principalmente la madura, es un fruto que posee una elevada capacidad antioxidante y un alto contenido de polifenoles, flavonoides y vitamina C.(AU)

Objective: To determine the antioxidant activity of thefruit of Rubus sparsiflorus (shiraca). Material and methods: A homogenate was preparedwith distilled water and centrifuged at 15,000 rpm for 10 min-utes, the supernatant was used to perform the analytical de-terminations. Polyphenols were determined using theSingleton and Rossi technique, flavonoids using the Jia, Tangand Wu technique, vitamin C using the Jagota and Dan tech-nique, and anthocyanins using the Giusti and Wrolstad tech-nique. Likewise, the antioxidant capacity was determined us-ing the FRAP (Benzie and Strain), DPPH (Brand-Williams,Cuvellier and Berset), ABTS (Rice-Evans, Miller and Paganga)techniques and the ascorbate/copper system (Uchida andKawakishi). Results: The mature shiraca showed a polyphenol contentof 415.4 mg GAE/100g of fruit, flavonoids 72.03 mg.CE/100gof fruit and anthocyanins 147.38 mg of cyanidin-3-gluco-side/100g of fruit that were higher than the green shiraca, in-stead, the content of vitamin C was similar in the mature fruit(108.35 mg/100g) and the green fruit (118.52 mg/100g).Likewise, the antioxidant activity of the mature fruit evaluatedwith the techniques FRAP (8.05 mmoles of Fe-II/100 g of fruit), DPPH (IC50 = 0.76 mg/mL), ABTS (IC50 = 0.147 mg/mL) andthe ascorbate/copper system (IC50 = 2.16 mg/mL) showedthat the mature fruit had higher antioxidant capacity than thegreen fruit. Conclusions: Shiraca, mainly the mature one, is a fruitthat has a high antioxidant capacity and a high content ofpolyphenols, flavonoids and vitamin C.(AU)

Untargeted Fecal Metabolomic Analyses across an Industrialization Gradient Reveal Shared Metabolites and Impact of Industrialization on Fecal Microbiome-Metabolome Interactions.

The metabolome is a central determinant of human phenotypes and includes the plethora of small molecules produced by host and microbiome or taken up from exogenous sources. However, studies of the metabolome have so far focused predominantly on urban, industrialized populations. Through an untargeted metabolomic analysis of 90 fecal samples from human individuals from Africa and the Americas-the birthplace and the last continental expansion of our species, respectively-we characterized a shared human fecal metabolome. The majority of detected metabolite features were ubiquitous across populations, despite any geographic, dietary, or behavioral differences. Such shared metabolite features included hyocholic acid and cholesterol. However, any characterization of the shared human fecal metabolome is insufficient without exploring the influence of industrialization. Here, we show chemical differences along an industrialization gradient, where the degree of industrialization correlates with metabolomic changes. We identified differential metabolite features such as amino acid-conjugated bile acids and urobilin as major metabolic correlates of these behavioral shifts. Additionally, coanalyses with over 5,000 publicly available human fecal samples and cooccurrence probability analyses with the gut microbiome highlight connections between the human fecal metabolome and gut microbiome. Our results indicate that industrialization significantly influences the human fecal metabolome, but diverse human lifestyles and behavior still maintain a shared human fecal metabolome. This study represents the first characterization of the shared human fecal metabolome through untargeted analyses of populations along an industrialization gradient. IMPORTANCE As the world becomes increasingly industrialized, understanding the biological consequences of these lifestyle shifts and what it means for past, present, and future human health is critical. Indeed, industrialization is associated with rises in allergic and autoimmune health conditions and reduced microbial diversity. Exploring these health effects on a chemical level requires consideration of human lifestyle diversity, but understanding the significance of any differences also requires knowledge of what molecular components are shared between human groups. Our study reveals the key chemistry of the human gut as defined by varied industrialization-based differences and ubiquitous shared features. Ultimately, these novel findings extend our knowledge of human molecular biology, especially as it is influenced by lifestyle and behavior, and provide steps toward understanding how human biology has changed over our species' history.

Adherencia a la suplementación con gomitas que contienen hierro hemo en niños de 6 a 8 años en el distrito de Ate-Lima

Objetivo: Determinar la adherencia a la suplementación con gomitas que contienen hierro hemo en niños de 6 a 8 años en el distrito de Ate en Lima. Materiales y métodos: Se realizó un muestreo no probabilístico de tipo intencional de 50 niños de 6 a 8 años de ambos sexos registrados en el municipio de Ate. Se incluyó a niños sin anemia, con anemia leve y anemia moderada. El nivel de hemoglobina se determinó al inicio y al término de la intervención. Cada niño ingirió una gomita con hierro hemo (9 mg de hierro elemental) durante 4 meses. Resultados: La adherencia al consumo fue del 100 %; ninguno de los niños manifestó haber sufrido efectos secundarios y a todos les agradó el sabor de las gomitas. Los niños con anemia moderada tuvieron una concentración de hemoglobina de 10,48 ± 0,48 g/dL al iniciar la intervención y 11,43 ± 0,38 g/dL al finalizar; los niños con anemia leve, 11,21 ± 0,14 g/dL al inicio y 12,17 ± 0,51 g/dL al finalizar la intervención, y los niños sin anemia, 11,68 ± 0,13 g/dL al inicio y 12,57 ± 0,53 g/dL al finalizar; el valor p en todos los grupos fue estadísticamente significativo (p = 0,000). El 94,74 % de los niños con anemia leve consiguieron normalizar sus niveles de hemoglobina. Conclusiones: Se observó una completa adherencia de los niños al consumo de las gomitas con hierro hemo y los niveles de hemoglobina se elevaron en todos los grupos.

Objective: To determine the adherence to heme iron gummy supplementation among children 6 to 8 years of age in the district of Ate, Lima. Materials and methods: A purposive non-probability sampling of 50 children 6 to 8 years of age, of both sexes, registered in the municipality of Ate. The study included children with no anemia, mild anemia and moderate anemia. The hemoglobin level was determined at the beginning and end of the intervention. Each child ingested a heme iron gummy (9 mg elemental iron) for four months. Results: Adherence to heme iron gummies consumption was 100 %; none of the children reported side effects and all of them liked the taste of the gummies. Children with moderate anemia, mild anemia and no anemia had a hemoglobin concentration of 10.48 ± 0.48 g/dL and 11.43 ± 0.38 g/dL, 11.21 ± 0.14 g/dL and 12.17 ± 0.51 g/dL, and 11.68 ± 0.13 g/dL and 12.57 ± 0.53 g/dL at the beginning and end of the intervention, respectively. The p value in all groups was statistically significant (p = 0.000). Out of the children with mild anemia, 94.74 % achieved normal hemoglobin levels. Conclusions: All age groups had good adherence to heme iron gummies consumption and increased their hemoglobin levels.

Evaluación de la capacidad antioxidante y compuestos bioactivos de tumbo (Passiflora mollissima) y cerezo (Prunus serotina)

Objetivo: Determinar el contenido de compuestos bioactivos y la capacidad antioxidante de los frutos tumbo (Passiflora mollissima) y cerezo (Prunus serotina). Materiales y métodos: Estudio analítico, experimental, longitudinal y prospectivo. Los frutos cerezo y tumbo se recolectaron en las regiones de Cusco, Moquegua y Arequipa. La técnica de Folin-Ciocalteu fue empleada para determinar el contenido de fenoles, y el cloruro de aluminio se utilizó para calcular los flavonoides. La actividad antioxidante se evaluó mediante las técnicas Ferric Reducing Ability of Plasma (FRAP), 2,2-difenil-picril-hidrazil (DPPH) y sustancias reactivas al ácido tiobarbitúrico (TBARS). Para estudiar el efecto hepatoprotector de las frutas, utilizamos ratas albinas que se clasificaron en un grupo control negativo, un grupo control positivo y cuatro grupos experimentales. Resultados: La mayor concentración de fenoles totales y flavonoides se encontró en el tumbo de la región Cusco (Quechua) (fenoles totales: 584,94 ± 134,62 mg EAG / 100 g y flavonoides :445,62 ± 7,94 mg EQ / 100 g). Para el radical DPPH, el valor IC50 del tumbo de la región Arequipa (Yunga) fue 0,41 ± 0,01 mg / mL. El tumbo de la región Cusco (Quechua) mostró el valor FRAP más alto (8,38 ± 0,32 mmol Fe2 + / 100 g). El cerezo de la región de Arequipa (Yunga) presentó la mayor concentración de fenoles totales (181,81 ± 34,1 mg EAG / 100 g) y flavonoides (205,18 ± 77,8 mg EQ / 100 g). El cerezo de Arequipa (Yunga) mostró una actividad antioxidante significativa al DPPH (2,1 ± 0,01 mg / mL), mientras que la capacidad antioxidante del cerezo de la región Cusco (Quechua), evaluada con la técnica FRAP, alcanzó un valor de 1,59 ± 0,2 mmol Fe2+/100 g. Las diferencias observadas fueron estadísticamente significativas. El tumbo mostró un mejor efecto hepatoprotector que el cerezo. Conclusiones: El tumbo de la región Cusco (Quechua) es una fuente importante de compuestos antioxidantes y muestra una elevada capacidad antioxidante (FRAP), mientras que el cerezo de la región Arequipa (Yunga) tiene un alto contenido de compuestos antioxidantes y una mayor capacidad antioxidante (DPPH).

Objective: To determine the content of bioactive compounds and antioxidant capacity of the banana passionfruit (Passiflora mollissima) and black cherry (Prunus serotina). Materials and methods: An analytical, experimental, longitudinal and prospective study. The black cherries and banana passionfruits were collected in the Cusco, Moquegua and Arequipa regions. The content of phenols and flavonoids were determined using the Folin-Ciocalteu reagent and aluminum chloride method, respectively. The antioxidant activity was evaluated using the ferric reducing ability of plasma (FRAP), 2,2-diphenyl-1-picryl-hydrazyl (DPPH) and thiobarbituric acid reactive substance (TBARS) techniques. Albino rats classified into a negative control group, a positive control group and four experimental groups were used to study the hepatoprotective effect of the fruits. Results: Banana passionfruits from the Cusco region (Quechua) showed the highest concentration of total phenols (584.94 ± 134.62 mg GAE/100 g) and flavonoids (445.62 ± 7.94 mg QE/100 g). Concerning the DPPH radical, the IC 50 value of banana passionfruits from the Arequipa region (Yunga) was found to be 0.41 ± 0.01 mg/mL. Banana passionfruits from the Cusco region (Quechua) showed the highest FRAP value (8.38 ± 0.32 mmol Fe2+/100 g). Black cherries from the Arequipa region (Yunga) had the highest concentration of total phenols (181.81 ± 34.1 mg GAE/100 g) and flavonoids (205.18 ± 77.8 mg QE/100 g). They also showed a significant antioxidant activity regarding the DPPH (2.1 ± 0.01 mg/mL), while the antioxidant capacity of black cherries from the Cusco region (Quechua), which was evaluated with the FRAP method, achieved a value of 1.59 ± 0.2 mmol Fe2+/100 g. The observed differences were statistically significant. Banana passionfruits showed a better hepatoprotective effect than black cherries. Conclusions: Banana passionfruits from the Cusco region (Quechua) are an important source of antioxidant compounds and show a high antioxidant capacity (FRAP), while black cherries from the Arequipa region (Yunga) have a high content of antioxidant compounds and a higher antioxidant capacity (DPPH).

Analysis of global human gut metagenomes shows that metabolic resilience potential for short-chain fatty acid production is strongly influenced by lifestyle.

High taxonomic diversity in non-industrial human gut microbiomes is often interpreted as beneficial; however, it is unclear if taxonomic diversity engenders ecological resilience (i.e. community stability and metabolic continuity). We estimate resilience through genus and species-level richness, phylogenetic diversity, and evenness in short-chain fatty acid (SCFA) production among a global gut metagenome panel of 12 populations (n = 451) representing industrial and non-industrial lifestyles, including novel metagenomic data from Burkina Faso (n = 90). We observe significantly higher genus-level resilience in non-industrial populations, while SCFA production in industrial populations is driven by a few phylogenetically closely related species (belonging to Bacteroides and Clostridium), meaning industrial microbiomes have low resilience potential. Additionally, database bias obfuscates resilience estimates, as we were 2-5 times more likely to identify SCFA-encoding species in industrial microbiomes compared to non-industrial. Overall, we find high phylogenetic diversity, richness, and evenness of bacteria encoding SCFAs in non-industrial gut microbiomes, signaling high potential for resilience in SCFA production, despite database biases that limit metagenomic analysis of non-industrial populations.

Estudio histopatológico de los efectos de la administración de hierro hemo y sulfato ferroso con vitamina C en cerebro e hígado de rata / Histopathological study of the effects of administering heme iron and ferrous sulfate with vitamin C in rat liver and brain

Objetivo: Determinar el efecto que ejerce la administración de hierro hemo y la de sulfato ferroso con vitamina C en hígado y cerebro de rata. Materiales y métodos: Se utilizaron ratas albinas Holtzman mantenidas en un bioterio con temperatura de 22 ± 2° C, humedad entre 50 y 70 % y 12 horas de luz y 12 horas de oscuridad, que recibieron 4,0 mg de hierro elemental/kg p.c. bajo la forma de hierro hemo o como sulfato ferroso + 10 mg de vitamina C durante siete días, a cuyo término se sacrificaron y se les extrajo sangre, hígado y cerebro. Se hicieron los cortes histológicos que se trataron con hematoxilina-eosina para la observación microscópica y en el suero se midió la capacidad antioxidante.Resultados: Los cerebros de las ratas que recibieron tratamiento con hierro hemo y sulfato ferroso + vitamina C no sufrieron alteraciones significativas, mientras que los cortes histológicos de hígado de ratas tratadas con hierro hemo mostraron un parénquima sin distribución polar, algunos núcleos carentes de citoplasma y numerosas células de Küpffer a nivel del sinusoide. En cambio, las ratas que fueron tratadas con sulfato ferroso + vitamina C presentaron un parénquima hepático deteriorado notablemente, algunas áreas con núcleos sueltos sin citoplasma y otras con citoplasma cuya membrana había desaparecido. Además, en algunas zonas, el parénquima hepático se encontraba homogenizado.Conclusiones: Los cerebros de las ratas tratadas con hierro hemo y las que recibieron sulfato ferroso + vitamina C prácticamente no sufrieron modificación alguna, en cambio, el hígado de las ratas tratadas con sulfato ferroso + vitamina C presentaron mayor daño hepático que las tratadas con hierro hemo.

Objective: To determine the effect exerted by the administration of heme iron and ferrous sulfate with vitamin C in rat liver and brain. Materials and methods:The study used Holtzman albino rats housed in a bioterium with a temperature of 22 ± 2 °C, humidity between 50 and 70 %, and 12 hours of light and 12 hours of darkness. They received elemental iron 4.0 mg/kg b.w. as heme iron or ferrous sulfate + vitamin C 10 mg for seven days, at which time they were sacrificed, and blood, liver and brain were extracted. Histological sections were made and treated with hematoxylin-eosin for microscopic observation, and serum antioxidant capacity was measured.Results: The brains of the rats treated with heme iron and ferrous sulfate + vitamin C did not undergo significant changes, while the histological sections of the livers of the rats treated with heme iron showed a parenchyma without polar distribution, some nuclei lacking cytoplasm and numerous Küpffer cells at the sinusoidal level. In contrast, the rats treated with ferrous sulfate + vitamin C had a significantly deteriorated hepatic parenchyma, some areas with loose nuclei without cytoplasm and others with disappeared cytoplasmic membranes. In addition, in some areas, the liver parenchyma was homogenized. Conclusions: The brains of the rats treated with heme iron and those with ferrous sulfate + vitamin C did not practically undergo any change. In contrast, the liver of the rats treated with ferrous sulfate + vitamin C had greater liver damage than those treated with heme iron.

Citroniella saccharovorans gen. nov. sp. nov., a member of the family Peptoniphilaceae isolated from a human fecal sample from a coastal traditional community member.

A novel Gram-stain-positive, non-motile, non-spore-forming coccus-shaped obligately anaerobic bacterium was recovered from a fecal sample obtained from an individual from a traditional community located on the southern coast of Peru. The results of analysis based on 16S rRNA gene sequencing indicated the novel bacterium to be phylogenetically distinct from other genera of members of the Peptoniphilaceae family, sharing a loose affinity with the genera Ezakiella, Finegoldia, Gallicola and Parvimonas. The major cellular fatty acids of the novel isolate were determined to be C16:0, C17:1ω8c, and C18:1ω9c. The DNA G+C content was 29.9 mol%. End products of metabolism from peptone yeast glucose broth (PYG) were determined to be acetate and methyl succinate. The diagnostic diamino acid present in the cell wall was lysine. On the basis of the phenotypic, chemotaxonomic and phylogenetic results the organism is a member of a novel genus belonging to the family Peptoniphilaceae for which the name Citroniella saccharovorans gen nov. sp. nov., is proposed. The type strain is M6.X9T (DSM 29873T=CCUG 66799T).

Generación de radicales libres por efecto de vitamina C sobre un jarabe antianémico de sulfato ferroso / Generation of free radicals by the effect of vitamin C on a ferrous sulfate antianemic syrup

Objetivo: Determinar el efecto que ejerce la vitamina C sobre el sulfato ferroso, principio activo de un jarabe antianémico. Materiales y métodos: La reacción que se produce entre el sulfato ferroso de un jarabe antianémico y la vitamina C se determinó al aplicar la técnica de descomposición de la desoxirribosa, que evalúa la formación de malondialdehído por acción de radicales libres. Resultados: En un medio de ensayo constituido por tampón fosfato 50 mM (pH 7,4), el jarabe antianémico de sulfato ferroso a una concentración 1,080 mM reaccionó con la vitamina C en concentraciones comprendidas entre 5,0 x 10-6 mM y 0,5 mM, generando radicales libres que disminuyen cuando se utiliza una concentración de vitamina C de 5,0 x 10-2 mM mientras que a una concentración 0,5 mM, se eleva. Cuando se usa sulfato ferroso en condiciones similares se aprecia un incremento de la generación de radicales libres que alcanza un valor máximo a una concentración de vitamina C de 5,0 x 10-6 mM que se mantiene invariable a concentraciones de dos órdenes de magnitud mayor y, ulteriormente, decrece a concentraciones más elevadas. La vitamina C a una concentración 1,0 mM reacciona con el sulfato ferroso utilizado en concentraciones comprendidas entre 0,270 y 2,160 mM describiendo una curva de tipo hiperbólica. En cambio, el jarabe de sulfato ferroso, utilizado en las mismas concentraciones, mostró un elevado incremento a bajas concentraciones de tipo no lineal pero que tuvo una respuesta lineal a partir de la concentración 0,540 mM del jarabe, respuesta que fue mayor a la alcanzada por el sulfato ferroso disuelto en agua destilada. Conclusiones: La vitamina C reacciona con el jarabe de sulfato ferroso y genera radicales libres, esta respuesta depende de las concentraciones relativas de sulfato ferroso, vitamina C y de los excipientes del jarabe.

Objective: To determine the effect of vitamin C on ferrous sulfate, the active ingredient of an antianemic syrup. Materials and methods: The reaction between the ferrous sulfate contained in an antianemic syrup and vitamin C was determined using the decomposition technique of deoxyribose, which evaluates the formation of malondialdehyde by the action of free radicals. Results: In an assay medium consisting of 50 mM phosphate buffer (pH 7.4), the ferrous sulfate antianemic syrup at a concentration of 1.080 mM reacted with vitamin C at concentrations between 5.0 x 10-6 mM and 0.5 mM, generating levels of free radicals that decrease when vitamin C is used at a concentration of 5.0 x 10-2 mM, and increase at a concentration of 0.5 mM. When ferrous sulfate is used under similar conditions, an increase in the generation of free radicals is observed, which reaches a maximum value with vitamin C at a concentration of 5.0 x 10-6 mM, remains unchanged at concentrations of two orders of magnitude higher, and subsequently decreases at higher concentrations. Vitamin C at a concentration of 1.0 mM reacts with ferrous sulfate used at concentrations between 0.270 and 2.160 mM, describing a hyperbolic curve. In contrast, ferrous sulfate syrup used at the same concentrations showed a high increase at low non-linear concentrations, but a linear response from the 0.540 mM concentration of the syrup, a response that was higher than that reached by the ferrous sulfate dissolved in distilled water. Conclusions: Vitamin C reacts with ferrous sulfate syrup generating free radicals. This response depends on the relative concentrations of ferrous sulfate, vitamin C and syrup excipients.

Peptoniphilus catoniae sp. nov., isolated from a human faecal sample from a traditional Peruvian coastal community.

A novel Gram-stain-positive, coccus-shaped, obligately anaerobic bacterium was isolated from a faecal sample obtained from an individual in a traditional community located off the southern coast of Peru. Comparative 16S rRNA gene sequence analysis showed the novel bacterium belonged to the genus Peptoniphilus but showed no particular relationship with any species, demonstrating less than 91 % 16S rRNA gene sequence similarity with all members of the genus. The major cellular fatty acids of the novel isolate were determined to be C10 : 0, C14 : 0, C16 : 0, C18 : 1ω9c and C18 : 2ω6,9c/anteiso-C18 : 0. The DNA G+C content was 34.4 mol%. End-products of metabolism from peptone-yeast-glucose broth (PYG) were determined to be acetate and butyrate. Based on the phenotypic, chemotaxonomic and phylogenetic results, the organism represents a novel species of the genus Peptoniphilus, for which the name Peptoniphilus catoniae sp. nov. is proposed. The type strain is M6.X2DT ( = DSM 29874T = CCUG 66798T).

Efecto hipoglicemiante de los extractos acuoso y etanólico de psidium guajava L. (Guayaba) en ratas diabéticas inducidas por aloxano / Hypoglycemic effect of aqueous and ethanol extracts of psidium guajava L. (guajava) in alloxan-induced diabetic rats

OBJETIVO: Evaluar la actividad antidiabética de los extractos acuoso y etanólico obtenidos a partir de las hojas de Psidium guajava L. en ratas diabéticas inducidas por aloxano. MAZTERIAL y METODOS: La hiperglicemia se indujo en ratas albinas mediante la administración de aloxano monohidrato (100 mg/kg ip). El extracto acuoso fue administrado en una sola dosis de 250 mg/kg, mientras que el extracto etanólico a las dosis de 250 y 500 mg/kg también a dosis única. La glucosa en sangre se determinó a las dos, cuatro y veinticuatro horas, después de la administración del aloxano. RESULTADOS: La administración de los extractos acuoso y etanólico de Psidium guajava L. tendieron a disminuir la concentración de glucosa en sangre. El extracto acuoso con una concentración de 250 mg/kg se encontró que era más potente que los extractos etanólicos, con la concentración de glucosa media más baja de 86,67 mg/dL, dos horas después de que se administró. El efecto del extracto etanólico sólo se observó en la concentración de 500 mg/kg con una ligera disminución de la glucosa en sangre. CONCLUSIÓN: Este estudio indicó una actividad antidiabética significativa del extracto acuoso de Psidium guajava L. en ratas diabéticas inducidas por aloxano.

OBJECTIVE: To evaluate antidiabetic activity of water and ethanol extracts from Psidium guajava L. leaves in alloxan-induced diabetic rats. MATERIAL and METHODS: Hyperglycemia was induced in albino rats by administering alloxan monohydrate (100 mg/kg i.p.). Water extract at a dose of 250 mg/kg was administered at a single dose, while ethanol extracts at doses of 250 and 500 mg/kg were also administered at a single dose. Blood glucose was determined two hours after administering the extracts. RESULTS: The addition of water and ethanol extracts of Psidium guajava L. tended to decrease the blood glucose concentration. The water extract at a concentration of 250 mg/kg was found to be more potent than ethanol extracts with the lowest mean glucose concentration of 86.67 mg/dL two hours after it was administered. The effect of ethanol extract was only observed at the concentration of 500 mg/kg with a slight decrease in blood glucose. CONCLUSION: This study indicated a significant antidiabetic activity of water extract of Psidium guajava L. in alloxan induced diabetic rats.

Subsistence strategies in traditional societies distinguish gut microbiomes.

Recent studies suggest that gut microbiomes of urban-industrialized societies are different from those of traditional peoples. Here we examine the relationship between lifeways and gut microbiota through taxonomic and functional potential characterization of faecal samples from hunter-gatherer and traditional agriculturalist communities in Peru and an urban-industrialized community from the US. We find that in addition to taxonomic and metabolic differences between urban and traditional lifestyles, hunter-gatherers form a distinct sub-group among traditional peoples. As observed in previous studies, we find that Treponema are characteristic of traditional gut microbiomes. Moreover, through genome reconstruction (2.2-2.5 MB, coverage depth × 26-513) and functional potential characterization, we discover these Treponema are diverse, fall outside of pathogenic clades and are similar to Treponema succinifaciens, a known carbohydrate metabolizer in swine. Gut Treponema are found in non-human primates and all traditional peoples studied to date, suggesting they are symbionts lost in urban-industrialized societies.

Evaluación de la técnica 2, 2-Difenil-i-Picrilhidrazilo (DPPH) para determinar capacidad antioxidante / Evaluation of Technical 2, 2 - diphenyl -i - Picrilhidrazilo (DPPH ) to determine antioxidant capacity

Este estudio evalúa la actividad antioxidante usando el método del radical libre 2,2-difenil-1-picrilhidracilo (DPPH). Este método se utiliza para determinar la capacidad antioxidante de alimentos y compuestos sintéticos; para este fin se ha hecho uso de este radical libre en concentraciones comprendidas entre 0,037 y 0,200 mM, así mismo, para llevar a cabo esta evaluación se utilizó los estándares de catequina y epicatequina en un rango de concentración que estuvo entre 6,67 x 10-3 y 2,2 x 10-2 mM. Los valores de IC50 para ambos estándares fueron dependientes de la concentración de DPPH, habiéndose observado que el valor anterior aumenta al incrementar la concentración de DPPH. El resultado obtenido en este estudio indica la importancia de la concentración del DPPH para evaluar la capacidad antioxidante...

We assessed the technique using free radical 2,2-diphenyl-1-picrilhidrazil (DPPH) used to determine the antioxidant capacity of foods and synthetic compounds; for that purpose this free radical has been used in concentrations between 0.037 and 0.2 mM, likewise, to perform this evaluation the catechin and epicatechin standards have been used in a concentration range of 6.67 x 10(-3) and 2.2 x 10(-2) mM. C1(50) values for both standards were dependent on the concentration of DPPH, having observed that the aboye value increases with increasing concentration of DPPH, for which reason it is suggested that all research use a single concentration of DPPH in the reaction medium...

Ezakiella peruensis gen. nov., sp. nov. isolated from human fecal sample from a coastal traditional community in Peru.

A novel Gram-stain positive, non-motile, non-sporeforming coccus-shaped, obligately anaerobic bacterium was isolated from a fecal sample of an individual residing in a traditional Peruvian community. The organism was characterized using biochemical, chemotaxonomic and phylogenetic methods. Comparative 16S rRNA gene sequence analyses and phenotypic characteristics demonstrated that the organism was biochemically and phenotypically related, but distinct, from a group of organisms referred to as the Gram-stain positive anaerobic cocci (GPAC). The major cellular fatty acids of the novel isolate were determined to be C16:0 (18.3%), C18:1ω9c (39.8%), C18:2ω6,9c/C18:0 ANTE (13.2%). Fermentation end products from PYG are acetate and formate. Cell-wall peptidoglycan was found to be A4α (L-Lys-L-Ala-L-Glu) and the G + C content was determined to be 38.4 mol%. Based on the phenotypic, chemotaxonomic, and phylogenetic results, Ezakiella peruensis gen. nov., sp. nov., is now proposed. The type strain is M6.X2(T) (DSM 27367(T) = NBRC 109957 (T) = CCUG 64571(T)).

Efecto del glicerol sobre la catálisis por fosfatasa ácida de bajo peso molecular de hígado de alpaca (lama pacos) / Effect of glycerol on catalysis by low molecular weight acid phosphatase from alpaca liver (lama pacos)

Objetivo: Determinar el efecto del glicerol sobre la hidrólisis del p-nitrofenil fosfato a pH 5,0 por fosfatasa ácida de bajo peso molecular de hígado de alpaca. Diseño: Estudio analítico experimental. Lugar: Centro de Investigación de Bioquímica y Nutrición, Facultad de Medicina, Universidad Nacional Mayor de San Marcos. Materiales: Se utilizó los reactivos químicos p-nitrofenil fosfato sal disódica, ácido acético glacial, glicerol, ácido tricloroacético, ácido sulfúrico, molibdato de amonio, ácido ascórbico, sulfato de amonio, sephadex G-75 (45-120), sulfoetil sephadex C-50 y etilendiaminotetraacético (EDTA). Métodos: Se determinó los parámetros cinéticos Km y Vmax utilizando como sustrato el p-nitrofenil fosfato, en presencia de concentraciones variables de glicerol. Así mismo, se determinó la velocidad de liberación de los productos de la reacción en función de la concentración de dicho nucleófilo. Principales medidas de resultados: Efecto del glicerol sobre la hidrólisis del p-nitrofenil fosfato. Resultados: El glicerol en concentraciones comprendidas entre 1,16 y 3,49 M incrementó linealmente la liberación del p-nitrofenol; en cambio, la formación del fosfato inorgánico -el segundo producto liberado- no se modificó. Así mismo, los valores de Km y Vmax se incrementaron linealmente dependientes de las concentraciones de glicerol, en un rango comprendido entre 0,58 y 2,32 M. Conclusiones: Un análisis de las modificaciones que ejerce el glicerol sobre los valores de Km y Vmax y la velocidad de liberación de los productos de la reacción permite sugerir un modelo en el que la fosfatasa ácida de bajo peso molecular de hígado de alpaca cataliza la hidrólisis de fosfomonoésteres a través de un mecanismo uni biordenado, con la formación de un complejo enzima-fosfato, que sería escindido por agua o un nucleófilo, como el glicerol; en este modelo a k2 le corresponde un valor mucho mayor que k3 y k4 N.

Objective: To determine the effect of glycerol on hydrolysis of p-nitrophenyl phosphate at pH 5,0 by low molecular weight acid phosphatase from alpaca liver. Design: Experimental analytical study. Setting: Biochemistry and Nutrition Research Center, Faculty of Medicine, Universidad Nacional Mayor de San Marcos, Lima, Peru. Materials: Disodic p-nitrophenyl phosphate salt, glacial acetic acid, glycerol, tricloroacetic acid, sulfuric acid, ammonium molibdate, ascorbic acid, ammonium sulphate, sephadex G 75 (45-120), sulpho ethyl sephadex C-50 and ethylene diaminotetraacetic (EDTA) chemical reactives. Methods: Both Km and Vmax kinetic parameters were determined with p-nitrophenyl phosphate as substrate in presence of different concentrations of glycerol. The rate of formation of products was determined as a function of the concentration of such nucleophile. Main outcome measures: Glycerol effect on p-nitrophenyl phosphate hydrolysis. Results: Glycerol linearly increased pnitrophenol release at concentrations between 1,16 and 3,49M. Instead, inorganic phosphate formation, the second product, was not modified. Also, Km and Vmax values increased linearly between 0,58 and 2,32 M depending on glycerol concentrations. Conclusions: Analysis of modifications induced by glycerol on Km and Vmax values as well as on liberation velocity of the reaction products suggests a model in which low molecular weight acid phosphatase isolated from alpaca liver catalyses phosphomonoesters hydrolysis through an uni biordered mechanism, with formation of an enzyme phosphate complex that will be splitted by water or a nucleophile such a glycerol; in this model, k2 corresponds to a much higher value than k3 or k4 N.

Efecto antioxidante y hepatoprotector del Petroselinum sativum (perejil) en ratas, con intoxicación hepática inducida por paracetamol / Petroselinum sativum (perejil) antioxidant and hepatoprotective effects in rats with paracetamol induced hepatic intoxication

Objetivo: Determinar el efecto antioxidante y hepatoprotector del perejil (Petroselinum sativum) en ratas con intoxicación hepática inducida por paracetamol. Lugar: Centro de Investigación de Bioquímica y Nutrición - ôLaboratorio de Bioquímica Clínica y Nutricional ôLeonidas Delgado Butrónõ ôEmilio Guija Pomaõ - Universidad Nacional Mayor de San Marcos. Lima, Perú. Diseño: Estudio analítico, transversal, prospectivo y cuasi experimental. Material: Ratas albinas Holtzman machos adultas. Métodos: Se utilizó 40 ratas de 2 meses de edad, con pesos entre 280 y 320 g, distribuidas aleatoriamente en cuatro grupos de 10 animales cada uno. Todos los grupos recibieron la misma dieta y agua ad libitum, además de los respectivos tratamientos, los cuales fueron administrados por vía oral diariamente, durante 5 días: paracetamol (administrado en una dosis de 200 mg/kg de peso corporal) para inducir la intoxicación hepática y, al mismo tiempo, un hepatoprotector, ya fuera farmacológico (fármaco hepatoprotector (FHP): Purinor®) o natural (perejil); además, un grupo de paracetamol solo y otro de control. Al término del período experimental, los animales fueron sacrificados. En suero sanguíneo se determinó aspartato aminotransferasa (AST), alanita aminotransferasa (ALT), gamma glutamil transferasa (GGT), grupos sulfhidrilo, proteínas totales y albúmina sérica; y en el homogenizado citosólico de hígado, fracción posmitocondrial, se determinó superóxido dismutasa, catalasa, glucosa-6-fosfato deshidrogenasa, grupos sulfidrilo, especies reactivas al ácido tiobarbitúrico (TBARS) o radicales libres y proteínas. Además, se realizó el estudio histopatológico del hígado, para identificar signos de necrosis y signos de regeneración posnecrótica. Principales medidas de resultados: Efecto antioxidante y hepatoprotector del perejil. Resultados: El perejil mostró un mejor efecto hepatoprotector que el FHP, frente a la acción nociva...

Objective: To determine the antioxidant and hepatoprotective effect of parsley (Petroselinum sativum) in rats with paracetamol-induced hepatic intoxication. Setting: Leonidas Delgado Butron - Emilio Guija Poma Clinical and Nutritional Biochemistry Laboratory, Biochemistry and Nutrition Research Center, Universidad Nacional Mayor de San Marcos, Lima, Peru. Design: Analytical, transverse, prospective and quasi-experimental study; only æpostÆ with quasi-control group design. Biologic materials: Adult male Holtzman albino rats. Methods: We utilized forty 2 months old adult rats weighing 280 to 320 g distributed at random in four groups 10 animals each. All groups received the same ad libitum diet and water along with respective treatments administered orally daily during 5 days: paracetamol was administered 200 mg/kg pc) to induce hepatic intoxication and concurrently a pharmacologic (hepatoprotective drug (HPD): Purinor®) or natural (parsley) hepatoprotector; another group was treated with paracetamol only and there was a control group. The animals were sacrificed at the end of the experimental period. We determined in serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma glutamyl transferase (GGT), sulphidril group, total proteins and serum albumin; and in liver postmitochondrial fraction cytosolic homogenates we determined superoxide dismutase, catalase, glucose-6-phosphate deydrogenase, sulphidril group, thiobarbituric acid reactive species (TBARS) or free radicals and proteins. Besides, histology study of the liver was done to identify both signs of necrosis and postnecrotic regeneration. Main outcome measures: ParsleyÆs antioxidant and hepatoprotective effects. Results: Parsley showed a better hepatoprotective effect than HPD against paracetamolÆs nocive effect, as evaluated by AST, ALT and GGT serum levels. Determination of glucose-6-phosphate dehydrogenase...

Mecanismo de acción de las fosfatasas ácidas de bajo peso molecular / Mechanism of action of low molecular weight acid phosphatases

Las fosfatasas ácidas son enzimas ampliamente distribuidas en la naturaleza y tienen la propiedad de hidrolizar fosfomonoésteres a pH 5,0, liberando como productos de la reacción un alcohol y fosfato inorgánico. Cuando se compara los valores de kcat/Km de las fosfatasas de hígado, de bovino, alpaca y porcino, nos permite sugerir que estas enzimas tienen elevada afinidad por el sustrato p-nitrofenil fosfato. Los productos que se liberan durante la catálisis por fosfatasa ácida, muestran que el fenol o el p-nitrofenol se comportan como inhibidores de tipo no competitivo, mientras que el fosfato inorgánico muestra una inhibición de tipo competitiva. Para evidenciar laprobable formación de un complejo covalente en la secuencia catalítica, se utilizó diversos nucleófilos más eficientes que el agua, tales como metanol, etanol y glicerol. Las modificaciones que produjeron en los valores Km, Vmax y los productos liberados en la reacción sugieren la formación de un complejo enzima-fosfato. El pH afecta los valores de Km y Vmax de las fosfatasas ácidas, un análisis del comportamiento de estas enzimas en un rango de pH comprendido entre 3,8 y 6,8 sugieren que en el sitio activo existe un residuo de aminoácido con un valor pKa de 6,0. El uso del dietilpirocarbonato, un compuesto que selectivamente reacciona con el residuo histidina en las proteínas, inhibe completamente a estas fosfatasas. Así mismo, un experimento de cinética de inhibición múltiple realizado en presencia de fosfato inorgánico y dietilpirocarbonato permite calcular un valor Ki que es igual al obtenido en otras condiciones experimentales. En tal sentido, las fosfatasas ácidas de bajo peso molecular catalizarían las reacciones a través de un modelo de tipo uni biordenado, con la formación de un complejo covalente intermedio, y que el residuo histidina participaría directamente en la catálisis.

Acid phosphatases are enzymes widespread in nature that hydrolyze phosphomonoesters at pH 5,0; this reaction yields alcohol and inorganic phosphate. Comparison of bovine, alpaca and porcine liver phosphatases kcat/Km values suggests these enzymes have a high affinity for p nitrophenyl phosphate substrate. Products that are released during acid phosphatase catalysis show that phenol or p nitrophenol behave as non competitive inhibitors, whereas inorganic phosphate shows competitive inhibition. Different nucleophiles more efficient than water have been used, such as methanol, ethanol and glycerol, showing the probable formation of a covalent complex in the catalytic sequence. Modifications produced in Km and Vmax values as well as in the reaction released products suggest the development of an enzyme-phosphate complex. pH affects acid phosphatases Km and Vmax values. Behavioral analysis of these enzymes at 3,8 to 6,8 pH range suggests the location of a pKa 6,0 aminoacid residue in the active site. The use of a diethylpyrocarbonate compound which selectively reacts with protein histidine residues completely inhibits this kind of phosphatases. Also, multiple inhibition kinetic survey performed in presence of inorganic phosphate and diethylpyrocarbonate allows a Ki value calculation equal to that obtained in other experimental conditions. In this respect, low molecular weight acid phosphatases would catalyze reactions through a uni biordered model, forming an intermediate covalent complex; histidine residues would directly participate in the catalysis.