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Opuntia ficus-indica consumption improves obesity and glucose and lipid metabolism, to name a few; however, the involved mechanism is poorly understood and attributed primarily to fiber. Obesity was recently shown to increase microglial cell activation in the hypothalamus. Here, we hypothesized that the addition of cactus flour (CF) to a high-fat diet (HFD) reduces hypothalamic inflammation, which is a key regulator of energy balance metabolism. Adult male C57Bl/6j mice underwent HFD (60% cal from fat) exposure over 12 weeks to develop obesity. The same type of HFD added with CF (17%) was administrated for 4 weeks. Bodyweight and food intake were recorded during the treatment, and glucose and insulin tolerance were evaluated at the end of the treatment. Additionally, the behavioral satiety sequence (BSS) was performed, and adiposity, along with microglia activation and density in the arcuate nucleus was determined. Herein, we found that CF normalizes body weight and adiposity without changes in absolute food intake. Moreover, CF modulated the cumulative caloric intake in a diet-dependent manner. Feed efficiency was decreased; glucose tolerance and insulin sensitivity were improved with CF treatment. BSS showed a decreased resting time and increased grooming for animals with an HFD-CF. Finally, CF consumption normalized microglia density in the arcuate nucleus of the hypothalamus in obese mice and significantly decreased their activation. This study shed new light on the understanding of the effects of cactus to reduce body weight, adiposity and improve glucose metabolism, and suggest they are mediated by the reduction of the microglial activation of the hypothalamic arcuate nucleus.

En los ecosistemas acuaticos se producen alteraciones cuando de forma continua estan expuestos al N-(fosfonometil) glicina (glifosato), especies susceptibles a un determinado grado de concentracion y tiempo de exposicion a este compuesto quimico. El objetivo del trabajo fue evaluar la concentracion letal media (CL 50(24) ) en Artemia franciscana, asi como la concentracion inhibitoria media poblacional (CI 50 ) y el coeficiente de forma (CF) en la cianobacteria Microcystis aeruginosa en ecosistemas acuaticos. Los resultados para A. franciscana fueron de una CL 50(24) 0.31 mg L -1 ; y sobre M. aeruginosa de una CI 50(72) 53.95 mg L -1 . En cuanto al estudio del coeficiente de forma, en las celulas control de M. aeruginosa resulto en un CF≈1, mientras que expuestas a 72h-NOEC (Concentracion sin Efecto Observable) fue de 2.95 mg L -1 . La CI 50(72) fue de 53.95 mg L -1 indicando que las celulas se mantienen esfericas, sin embargo, hay cambios significativos en su volumen y superficie celular en la CI 50(72) de 7.69 ± 1.69 µm 3 con un 33% en reduccion de volumen comparada con la celula control, lo que refleja los peligros ecotoxicologicos de este herbicida. La exposicion al glifosato resulto de categoria I (altamente toxica) en A. franciscana y categoria II (toxica) en M. aeruginosa , de acuerdo con la clasificacion de la Agencia de Proteccion Ambiental de los Estados Unidos (U.S. EPA).

Gallic (GA) and ellagic (EA) acids are present in foods, medicinal plants, teas, and dietary supplements. An acute toxicological study was conducted by oral administration of both compounds alone (200, 1000, and 2000 mg/kg) and combined (2000 mg/kg) and their effects on the electron transport chain (ETC) and the ROS production in kidney mitochondria further evaluated. All treatments induced a dose-dependent heart, lung, and kidney injury. However, the intensity of these effects varied according to the substance, with greater cardiac and renal toxicity for EA and pulmonary injury for GA, while the combination attenuated the toxicity of the isolated molecules. All substances inhibited the activity of complexes II, III, and IV of the ETC from renal mitochondria. However, no changes were observed regarding mitochondrial ROS production. These compounds have a non-negligible inherent deleterious potential, so their uncontrolled use at high doses (≥200 mg/kg) could cause undesirable effects.

Considerable variability in methane production and emissions has been reported in mangroves, explained by methane inhibition and oxidation. In this study, soil pore waters were collected from mangrove forests located in the Gulf of California (Mexico) exposed to shrimp farm disturbance. The δ13C of dissolved inorganic carbon (DIC) and CH4 were analyzed along with the δ13C of the soil organic matter to assess the proportion of CO2 derived from methanogenesis, its main pathway, and the fraction of methane oxidized. We performed slurry incubation experiments to fit the isotope–mass balance approach. Very low stoichiometric ratios of CH4/CO2 were measured in pore waters, but isotope mass balances revealed that 30–70% of the total CO2 measured was produced by methanogenesis. Mangrove soils receiving effluent discharges shifted the main methanogenesis pathway to CO2 reduction because of an increase in refractory organic matter. Isotope–mass balances of incubations indicated that methane was mainly oxidized by anaerobic oxidation of methane (AOM) coupled to sulfate reduction, and the increase in recalcitrant organic matter should fuel AOM as humus serves as a terminal electron acceptor. Since methanogenesis in mangrove soils is strongly controlled by the oxygen supply provided by mangrove roots, conservation of the forest plays a crucial role in mitigating greenhouse gas emissions., CONACyT: PROFAPI, Spanish Ministry of Science and Innovation (Grant: CGL2014-54502) and CSIC (Grant: I-COOP+2020–COOPA20433) funded this research.

The Reverse Osmosis desalination has become a technological option to guarantee an adequate drinking water supply in zones with water scarcity . Nevertheless, the process is accompanied by potential negative impacts on coastal ecosystem, especially due to chemical discharges. Taking into account the environmental risk presented by these chemical mixtures, in this work we used a short-term toxicity bioassay with Artemia franciscana nauplii expressed in lethality to exposures individually and their combinations. Results showed that toxicity degree from single exposures were C 5 H 8 O 2 > NaClO > CuSO 4 > KMnO 4 > FeCl 3 , indicated that C 5 H 8 O 2 was the most toxic biocide. However, all compounds in combination with C 5 H 8 O 2 exhibited a very strong antagonism. Except, in mixtures NaClO/FeCl 3 and CuSO 4 /KMnO 4 resulted in additive effect. This environmental assessment will allow reduce risk significantly on the concentrate considering the sensitivity of the marine ecosystem to the application of chemical agents during the desalination process.

espanolFactores ambientales como el pH, afectan la tasa de crecimiento, la productividad y la toxicidad de los metales en microalgas. Esta investigacion reporta el crecimiento exponencial de dos cepas de Dictyosphaerium chlorelloides, una tipo salvaje (Dc1Mwt) y otra resistente a cadmio (DcRCd100) bajo diferentes rangos de pH en el medio de cultivo en 1 a 15 dias de exposicion. Los resultados revelan que, la cepa DcRCd100 presento una tasa de crecimiento maxima en rangos de pH cercanos al neutro a medida que se incrementa en el tiempo (pH 8.0, m = 0.93 al decimo dia), ademas, con una capacidad de crecimiento limitada a valores de pH moderadamente acidos (pH 4.0, m = 0.67 al 1er dia de exposicion, pH 5.0 m = 0.16, 0.13 a los 10 y 15 dias, respectivamente). Mientras que, la cepa Dc1Mwt presento su maximo crecimiento a pH de 9.0, conforme se incrementa en el tiempo de exposicion (m = 2.17 al dia 15). Sin embargo, esta cepa no puede mantener una tasa de crecimiento a los valores de pH mas bajos ensayados en todos los tiempos de exposicion. Estos resultados sugieren que, la cepa DcRCd100 muestra cambios en la division celular, asi como en la actividad fotosintetica para hacer frente a las condiciones en los rangos de pH moderadamente acidos, pero no puede crecer en entornos alcalinos. EnglishEnvironmental factors such as pH affect the growth rate, productivity, and the toxicity of metals in microalgae. This research reports the exponential growth of both wild-type (Dc1Mwt) and cadmium-resistant (DcRCd100) strains of Dictyosphaerium chlorelloides under different pH ranges at 1 to 15 days of exposure. The results reveal that DcRCd100 strain had a maximum growth rate at pH ranges close to neutrality as time increases (pH 8.0, m = 0.93 on 10th day), besides with limited growth capacity to moderately acidic pH (pH 4.0, m = 0.67 at 1st day; pH 5.0 m = 0.16, 0.13 at 10 and 15th days respectively). Whereas, Dc1Mwt strain grows with a maximum growth rate at pH 9.0, with an increase at longer exposure time (m = 2.17 on the 15th day). However, this strain was unable to maintain growth rates at the lowest pH tested at all exposure times. These results suggested that DcRCd100 shows changes in cell division as well as in the photosynthetic activity to cope with slightly acidic pH ranges, although it was unable to grow in alkaline environments

Changes induced on freshwater microalga Dictyosphaerium chlorelloides (Dc(wt)) acclimated in the laboratory until their survival in culture media enriched with cadmium 100 µM have been studied. Cadmium removal by living cells of this Cd-resistant (Dc(CdR100)) strain was tested in cultures exposed to 100 µM Cd during 30 days. Cell dimensions were measured under light microscopy, and cell growth was studied. Photosynthetic yield (ΦPSII) was analyzed and the photosynthetic oxygen development and respiration response was obtained. Results show that Dc(CdR100) strain exhibited significant cell morphology changes in comparison to Dc(wt) cells, which affected both surface area and cell biovolume. Malthusian fitness analysis showed that Dc(CdR100) strain living in Cd-enriched culture had developed a lower capacity of nearly 50% growth, and its photosynthetic oxygen development and respiration response were significantly reduced in both light and dark photosynthetic phases. Dc(CdR100) strain showed a very high capacity to remove cadmium from the aquatic environment (over 90%), although most of the removed heavy metal (≈70%) is adhered to the cell wall. These specific characteristics of Dc(CdR100) cells suggest the possibility of using this strain in conjunction with Dc(wt) strain as bioelements into a dual-head biosensor, and in bioremediation processes on freshwater polluted with Cd.

Summary Ripening is one of the most important processes to occur in fruits and involves changes in colour, flavour and texture. An important goal in quality control of fruits is to substitute traditional sensory testing methods with reliable and quantitative methods. In this study, methyl jasmonate (MJ) (220 μL L−1) and calcium chloride (at 1%) were applied to guava fruits stored at 6 °C. The compression test (CT) and acoustic impact test were used to monitor the shelf life of guavas. The results obtained using both techniques showed that Young’s modulus diminishes as a function of time in all samples; however, the texture of samples treated for 20 days with MJ deteriorated unacceptably, a condition which did not occur in the samples treated with calcium chloride. The control samples had a shelf life of 20 days. In conclusion, it appears that the acoustic impact test is more appropriate than the CT and has the additional advantage of being a nondestructive technique.

This paper reports the acute toxicity of three biocides used in the disinfection of cooling towers, tetrakis(hydroxymethyl) phosphonium chloride (THPC), trichloroisocyanuric acid (TCIC), and sodium bromide (NaBr), on Artemia larvae, their effect on the phototactic response of this organism, and the potential of bioaccumulation in this species. The 24-h median lethal concentration (LC50) values for these biocides with respect to 24-, 48-, and 72-h-old Artemia, determined by static bioassays, showed the following rank order of toxicity: THPC < TCIC < NaBr. An age-dependent increase in sensitivity was seen for each compound. All three biocides reduced the phototactic response of 24-h-old Artemia larvae in 24-h static bioassays; the median inhibitory concentration ratios obtained were 30 to 40 times lower than their respective 24-h LC50 values. The results suggest that phototaxis bioassays could provide the speed and simplicity required for screening many potential pollutants for harmful effects. The bioconcentration factors obtained for Artemia larvae exposed to 10% LC50 for 168 h in renewal assays were 93.75, 1.67, and 0.23 for THPC, TCIC, and NaBr, respectively. This shows these biocides pose no bioaccumulation risk in this organism, although the value of 93.75 obtained for THPC is close to the threshold above which such a risk is considered to exist.

Instituto de Investigaciones Agropecuarias y Forestales. Facultad de Biología. Facultad de Medicina Veterinaria y Zootecnia. Facultad de Agrobiología. Facultad de Químico Farmacobiología. Programa Institucional de Maestría en Ciencias Biológicas Gallic (GA) and ellagic (AE) acids are phenolic compounds that coexist in fruits, vegetables, and medicinal plants. In recent years, the Food and Drug Administration (FDA) has warned about the indiscriminate use of high concentrations of nutritional supplements of these products based on alleged attributions of beneficial health effects. The present study investigated the acute oral toxicity of these compounds (200, 1000, and 2000 mg/kg), as well as their combination (1000 mg/kg AG + 1000 mg/kg AE) in Wistar rats following OECD guideline 423. The compounds were administered orally in a single dose. Bodyweight, food consumption, and relative organ weight were determined, and biochemical, hematological, and histopathological analyzes were performed. In addition, the impact of the maximum doses on the activity of the four complexes of the electron transport chain in the renal mitochondria and their influence on the production of reactive oxygen species (ROS) were analyzed. There were no deaths or changes in clinical signs with any of the treatments studied. The AE produced a decrease in the coloration of the lungs and pericardial tear, while the GA (2000 mg/kg) caused a decrease in the relative weight of the kidneys. Both the GA and the combination generated a significant increase in platelet count, while the AE and the combination caused a significant increase in urea, and the AE caused the increase of creatinine levels. The presence of kidney, heart, and lung damage related to the three treatments was confirmed by the histopathological analysis, although the intensity of the damage varied according to the type of substance. AE was considered to be the most nephrotoxic and cardiotoxic compound, while GA caused the highest deleterious effects on the lung. Los ácidos gálico (GA) y elágico (AE) son compuestos fenólicos que coexisten en frutas, verduras y plantas medicinales. En los últimos años la Food and Drug Administration (FDA) ha alertado sobre el uso indiscriminado de altas concentraciones de suplementos alimenticios de estos productos con base en supuestas atribuciones de efectos beneficiosos para la salud. El presente estudio investigó la toxicidad oral aguda de estos compuestos (200, 1000 y 2000 mg/kg), así como de su combinación (1000 mg/kg GA + 1000 mg/kg AE) en ratas Wistar siguiendo la guía 423 de la OCDE. Los compuestos fueron administrados por vía oral en dosis única. Se determinó el peso corporal, el consumo de alimento, el peso relativo de los órganos y se realizaron análisis bioquímicos, hematológicos e histopatológicos. Además, se analizó el impacto de las máximas dosis sobre la actividad de los cuatro complejos de la cadena de transporte electrónico de la mitocondria renal y su influencia sobre la producción de especies reactivas de oxígeno (ERO). No se produjeron muertes ni alteraciones de signos clínicos con ninguno de los tratamientos estudiados. El AE produjo una disminución de la coloración de los pulmones y desgarre pericárdico, mientras que el GA (2000 mg/kg) generó disminución del peso relativo de los riñones. Tanto el GA como la combinación generaron un incremento significativo en el conteo de plaquetas, mientras que el AE y la combinación provocaron un incremento significativo de la urea y el AE provocó un aumento en los niveles de la creatinina. A nivel histopatológico se confirmó la presencia de daño renal, cardíaco y pulmonar relacionado con los tres tratamientos, aunque la intensidad del daño varió según el tipo de sustancia. El AE resultó ser el compuesto más nefrotóxico y cardiotóxico, mientras que el GA provocó mayores efectos deletéreos sobre el pulmón.

Instituto de Investigaciones Agropecuarias y Forestales. Instituto de Investigaciones sobre los Recursos Naturales. Instituto de Investigaciones Químico Biológicas. Facultad de Biología. Facultad de Medicina Veterinaria y Zootecnia. Facultad de Químico Farmacobiología. Programa Institucional de Doctorado en Ciencias Biológicas The metals present in the aquatic ecosystem have a toxic profile with the ability to bioaccumulate and consequently biomagnifies along the aquatic trophic chain. These metal pollutants induce high sensitivity in most aquatic organisms, while others such as some species of microalgae become resistant. The aim of this doctoral thesis project was to determine the toxic effect that cadmium has on a freshwater microalgae strain with cosmopolitan distribution Dictyosphaerium chlorelloides, to obtain a resistant strain from its genetic and/or structural changes exposed to high cadmium concentrations, as well as the behavior under fluctuations of environmental factors and interaction of the Cd-resistant strain with other metals, in relationship to multi-resistance. According to the results obtained, the biological fitness and selection coefficient were evaluated in the absence of the selective agent, with a reduction of 34.78% (selection coefficient) in survival and leaving descendants with the resistance capacity with a value of m of 1.65 ± 0.33 compared to Dc1Mwt of 2.53 ± 0.55. In addition, DcRCd100 showed a reduction in cell volume and surface area of 75 and 61%, respectively, which is reflected as a fitness cost in of the Cd-resistant strain in the absence of the metal, probably with phenotypic changes. In photosynthesis, DcRCd100 (ΦPSII) exhibited a 20% reduction in PSII activity with modifications in the photosynthetic apparatus. In oxygen balance, resulted in an inhibition of 29.95 ± 3.91% of gross primary productivity (Pg). During fluctuations in photonic incidence a net efficiency (Pn) of 42.73 ± 18.27% was reported at low incidences of 50 μmol m-2 s-1. Los metales presentes en el ecosistema acuático poseen un carácter tóxico con capacidad de bioacumularse y por consecuencia biomagnificarse a lo largo de la cadena trófica acuática. Estos contaminantes metálicos inducen alta sensibilidad en la mayoría de los organismos acuáticos, mientras que otros como algunas especies de microalgas se vuelven resistentes. El objetivo del presente proyecto de tesis doctoral fue determinar el efecto tóxico que presenta el cadmio sobre una cepa de microalga de agua dulce con distribución cosmopolita tipo salvaje Dictyosphaerium chlorelloides, obtener una cepa resistente a partir de sus cambios genéticos y/o estructurales expuesta a altas concentraciones de cadmio, así como el comportamiento bajo fluctuaciones de factores ambientales e interacción de la cepa Cd-resistente con otros metales, en términos de multiresistencia. De acuerdo con los resultados obtenidos, se evaluó la aptitud biológica y coeficiente de selección en ausencia del agente selectivo, con una reducción del 34.78% (coeficiente de selección) en la supervivencia y dejar descendientes con la capacidad de resistencia con un valor de m de 1.65±0.33 comparada con Dc1Mwt de 2.53 ± 0.55. Además, DcRCd100 presentó reducción en el volumen y superficie celular del 75 y 61%, respectivamente, que se refleja como un costo en la aptitud de la cepa Cd-resistente en ausencia del metal, posiblemente con modificaciones fenotípicas. En fotosíntesis, DcRCd100 (ΦPSII), exhibió 20% de reducción en la actividad del PSII con modificaciones en el aparato fotosintético. En balance de oxígeno, DcRCd100 resultó en una inhibición del 29.95 ± 3.91% de productividad primaria bruta (Pg). Durante fluctuaciones en incidencia fotónica se reportó una eficiencia neta (Pn) de 42.73 ± 18.27% a bajas incidencias de 50 μmol m-2 s-1.

Instituto de Investigaciones Agropecuarias y Forestales. Facultad de Biología. Facultad de Medicina Veterinaria y Zootecnia. Facultad de Agrobiología. Facultad de Químico Farmacobiología. Programa Institucional de Maestría en Ciencias Biológicas Formaldehyde and copper sulphate are commonly used in the industry as surface cleaning agents and as algaecides in water treatment plants, this means they are usually thrown into water bodies. Their potential and environment impact have been studied thoroughly. The combined effects that these toxic products have provoke a greater negative impact than those caused individually. Polluting agents, such as metals, are highly dependent on abiotic factors (temperature, pH and salinity), which modify the chemical species that are present. The cupric ion (Cu2+) found in water bodies at 7.4 pH is the most available toxic species. It is able to be added to food chains and unleashing bioconcentration, bioaccumulation and biomagnifications processes. The objective of this study was to evaluate the water’s acute toxicity (LC50) of copper sulphate, formaldehyde and their binary mix (1:1 proportion) in “Artemia franciscana” “nauplii I” of 24 hours of age. The “nauplii I” were exposed to a synthetic sea water solution at formaldehyde concentrations of 0.3, 0.6, 0.9, 1.2, 1.5, 1.8, 2.1 and 2.4 mg/L for a period of 24 hours. The resulting LC50‘s for copper sulphate and formaldehyde were 1.4 mg/L and 1.38 μL/L respectively. Compared to the acute toxicity classification proposed by the Organization for Economic Cooperation and Development (OECD) and the US Environmental Protection Agency (EPA), the copper sulphate’s LC50 corresponds to a moderately toxic substance while the formaldehyde’s corresponds to a highly toxic one. The acute toxicity results of the mix show LC50-24h values of 1.16 mg/L for copper sulphate and 0.71 μL/L for formaldehyde. The mixture’s type of interaction is synergistic according to the Synergic “Proportion (SP)” and “Concentration Addition (CA)” models. El formaldehido y sulfato de cobre son comúnmente utilizados en la industria, para limpieza de superficies como alguicidas en plantas de tratamiento de aguas y finalmente son vertidos a los cuerpos de agua. Los efectos combinados que estos productos tóxicos pueden tener, provocan un impacto negativo mayor que como componentes individuales. Los metales son altamente dependientes de los factores abióticos los cuales modifican las especies químicas presentes, el ion cúprico (Cu+2) en cuerpos de agua a pH 7.4 es la especie tóxica disponible e incorporada a las cadenas alimentarias. En el presente trabajo se evaluó la (LC50) del sulfato de cobre, formaldehido y su mezcla binaria (proporción 1:1) en nauplios I de Artemia franciscana de 24 h de edad; estos se expusieron en solución de agua marina sintética a concentraciones de 0.3, 0.9, 1.2, 1.5, 1.8, 2.1, 2.4 mg/L sulfato de cobre y de 0.54, 0.71, 0.89, 1.11, 1.32, 1.5, 1.8, 2.02, 2.17, 2.84, 3.59, 4.44, 5.37, 6.39, 7.48 μL/L. de formaldehido. LC50s resultantes para sulfato de cobre y formaldehido fueron 1.4 mg/L y 1.38μL/L respectivamente. Los resultados de toxicidad aguda (LC50-24h) de la mezcla, de 1.16 mg/L para el cobre y 0.71μL/L para el formaldehido. Según la clasificación de toxicidad aguda propuesta por la Organización para la Cooperación y el Desarrollo Económicos (OCDE), la LC50 de cobre corresponde a una sustancia moderadamente tóxica, y el formaldehido altamente toxica. El tipo de interacción en la mezcla es sinérgico de acuerdo a los modelos Proporción Sinérgica (PS) y Concentración Adición (CA).