Effect of miR-96-5p targeting IRS1 on apoptosis of PC12 cells induced by aluminum maltol / 中华劳动卫生职业病杂志

Objective: To investigate the effect and mechanism of miR-96-5p on apoptosis of PC12 cells induced by maltol aluminum. Methods: In January 2021, PC12 cells at logarithmic growth phase were divided into blank control group and low, medium and high dose group. Cells in each group were treated with 0, 100, 200 and 400 μmol/L maltol aluminum for 24 hours respectively. Cells were collected and cell apoptosis rates were detected by flow cytometry, miR-96-5p and insulin receptor substrate 1 (IRS1) mRNA expressions were detected by qRT-PCR, and the protein expression levels of cysteine protease 3 (Caspase3) 、activated cysteine protease 3 (Cleaved-caspase3) 、IRS1、phosphorylated protein kinase B (p-AKT) and phosphorylated glucose synthesis kinase 3β (p-GSK3β) were detected by western blotting. The target binding relationship between miR-96-5p and IRS1 was detected by double luciferase reporter gene experiment. The miR-96-5p inhibitor cells and negative control cells were constructed after transfecting PC12 cells with miR-96-5p inhibitor for 24 hours. The cells were divided into blank control group, negative control group, aluminum exposure group, aluminum exposure+negative control group, aluminum exposure+miR-96-5p inhibition group, and miR-96-5p inhibition group. After transfecting PC12 cells with miR-96-5p inhibition and IRS1 siRNA for 24 h, the cells were divided into aluminum exposure+miR-96-5p inhibition+negative control group and aluminum exposure+miR-96-5p inhibition+IRS1 inhibition group. The control group was cultured in complete culture medium, and cells in the aluminum exposure group were treated with 200 μmol/L maltol aluminum for 24 hours. Cells in each group were collected and the apoptosis rate, miR-96-5p and IRS1 mRNA expression levels, as well as protein expression levels of Caspase3, Cleaved-caspase3, IRS1, p-AKT, and p-GSK3β were measured. Results: After 24 hours of exposure, compared with blank control group and low-dose group, the apoptosis rates, relative expressions of Caspase3 and Cleaved-caspase3 proteins, and relative expressions of miR-96-5p in the medium and high-dose groups of PC12 cells were significantly increased, while the relative expression levels of IRS1 mRNA, IRS1, p-AKT and p-GSK3β proteins were significantly decreased (P<0.05). Targetscan prediction and double luciferase report experiment both proved that IRS1 was a direct target gene of miR-96-5p. In the transfection experiment, compared with the aluminum exposure group, the apoptosis rate, the relative expressions of Caspase3 and Cleaved-caspase3 proteins, the relative expression of miR-96-5p in the aluminum exposure+miR-96-5p inhibition group were significantly decreased, while the relative expression levels of IRS1 mRNA and IRS1, p-AKT and p-GSK3β proteins were significantly increased (P<0.05). In the IRS1 low expression experiment, compared with the aluminum exposure+miR-96-5p inhibition+negative control group, the apoptosis rate, the relative expressions of Caspase3 and Cleaved-caspase3 proteins in the aluminum exposure+miR-96-5p inhibition+IRS1 inhibition group were significantly increased, while the relative expression levels of IRS1 mRNA and IRS1, p-AKT and p-GSK3β proteins were significantly decreased (P<0.05) . Conclusion: The increased expression of miR-96-5p and the targeted inhibition of IRS1 may be one of the mechanisms of apoptosis of PC12 cells induced by maltol aluminum exposure.

The effect of aluminum treatment on metabolism in oil palm seedlings

Due to rainfall and high temperatures, the Amazonian soil undergoes changes in its source material and leaching of base cations. This results in deep, infertile, and acidic soil. Aluminum present in acidic soil impairs plant growth and development by inhibiting root formation, enzymatic reactions, absorption, transport, and nutrient utilization. This study aimed to evaluate the effects of aluminum dosage on the metabolism of the oil palm Elaeis guineensis Jacq. The study was conducted in a greenhouse at the Federal Rural University of Amazonia. The experimental design was randomized, with five replications, in which dosages of 0, 10, 20, 30, and 40 mg L-1 aluminum chloride (AlCl3.6H2O) were administered. Electrolyte leakage, nitrate, nitrate reductase, free ammonium, soluble amino acids, proline content, and soluble proteins were analyzed in the leaves and roots of the oil palm. The highest concentration of aluminum was found in the roots. AlCl3 treatment at 40 mg L-1 increased electrolyte leakage, nitrate, ammonium, and proline concentrations in the roots, and amino acid concentrations in both the leaves and roots. Furthermore, a decrease in nitrate reductase enzyme activity was observed in the roots. This study demonstrates that the oil palm has mechanisms of tolerance to aluminum toxicity.

Research progress of epigenetic regulation in the pathogenesis of aluminum exposure / 中华预防医学杂志

Aluminum is one of the most abundant elements on earth. Aluminum compounds are widely used in food additives, antacids, cooking utensils and so on. Human exposure to aluminum is mainly through diet and drinking water, while excessive intake of aluminum can accumulate in tissues and cause toxic reactions. In the central nervous system, aluminum exposure is closely related to a series of nervous system diseases such as Alzheimer's disease, Parkinson's disease and amyotrophic lateral sclerosis. Epigenetic modification refers to the regulation of gene expression without changing the DNA sequence, and its regulatory disorders can lead to abnormalities and diseases of the central nervous system. This paper describes the regulation of epigenetics and its components, including DNA methylation, histone modification and non-coding RNA, in aluminum-induced neurotoxicity, in order to provide insights into the epigenetic mechanism of aluminum-induced neurotoxicity.

Concentración de aluminio en carne cocida almacenada en bandejas de aluminio descartables / Aluminum concentration in cooked beef stored in disposable aluminum trays

El aluminio puede ser consumido por personas a través de la contaminación de alimentos y el agua. Los metales pesa­dos en alimentos de origen animal son un riesgo potencial para la salud de los consumidores. En algunos países, es una práctica habitual que las comidas cocinadas listas para el consumo se presenten y mantengan calientes en bandejas de aluminio en tiendas minoristas, como locales de comida rápida y supermercados. No hay información disponible sobre el desprendimiento de metal en este tipo de recipiente de conservación de alimentos. El objetivo de este estudio fue determinar la concentración de aluminio en la carne y en los líquidos de cocción almacenados en bandejas de aluminio descartables. El diseño del estudio incluyó carne bovina cocida almacenada sola, en una salsa acuosa de hierbas a pH 7, y en una salsa acuosa cítrica (a base de limón) a pH 4, para simular condiciones encontradas en la práctica minorista. El Comité Mixto FAO / OMS de Expertos en Aditivos Alimentarios estableció una ingesta semanal tolerable provisional de 2 mg Al kg-1 de peso corporal. Una sola porción de 250 g de carne en salsa ácida almace­nada en una bandeja de aluminio calentada durante 1, 2, 4 u 8 horas contribuiría con 0,9%, 3,4%, 6,9% y 19,8% respectivamente de acuerdo al límite tolerable. Aunque la carne se mantiene caliente durante largos períodos en bandejas de aluminio descartable, el contenido de aluminio no se acerca a los límites actualmente recomendados. Este estudio proporciona datos que sugieren que puede ser prudente limitar el consumo de este tipo de comidas a base de carne con salsas ácidas almacenadas calientes por tiem­pos extendidos en contenedores de aluminio.

Aluminium can be consumed by people through contamination of foods and in water. Heavy metals in foods of animal origin are a potential risk to the health of consumers. It is common practice in some countries that ready-to-eat cooked meals are often presented and maintained hot in aluminium trays in retail outlets such as fast food take-out stores and supermarkets. There are not available information about the detachment of metal in this kind of container food preservation. The objective of this study was to determine the concentration of aluminium in meat and cooking liquids stored in disposable aluminium trays. The design of the study included cooked beef meat stored either alone, or in an aqueous sauce of herbs at pH 7, or in a citric (base of lemon) aqueous sauce at pH 4, to simulate a range of conditions found in retail practice. The Joint FAO/WHO Expert Committee on Food Additives established a provisional tolerable weekly intake of 2 mg Al kg body weight-1. A single 250 g portion of meat in acid sauce stored in a heated aluminium tray for 1, 2, 4, or 8 hours would contribute 0.9%, 3.4%, 6.9% or 19.8% towards this tolerable limit, respectively. Although the aluminium content in meat held warm for long periods in aluminium foil trays does not approach the consumption limits currently recommended, this study provides data that suggest that is may be prudent to limit consumption of ready-to eat meat-based meals with acid sauces stored warm in aluminium containers for extended times.

Reduction of adult hippocampal neurogenesis is amplified by aluminum exposure in a model of type 2 diabetes

In this study, we investigated the effects of chronic aluminum (Al) exposure for 10 weeks on cell proliferation and neuroblast differentiation in the hippocampus of type 2 diabetic rats. Six-week-old Zucker diabetic fatty (ZDF) and Zucker lean control (ZLC) rats were selected and randomly divided into Al- and non-Al-groups. Al was administered via drinking water for 10 weeks, after which the animals were sacrificed at 16 weeks of age. ZDF rats in both Al- and non-Al-groups showed increases in body weight and blood glucose levels compared to ZLC rats. Al exposure did not significantly affect body weight, blood glucose levels or pancreatic β-cells and morphology of the pancreas in either ZLC or ZDF rats. However, exposure to Al reduced cell proliferation and neuroblast differentiation in both ZLC and ZDF rats. Exposure to Al resulted in poor development of the dendritic processes of neuroblasts in both ZLC and ZDF rats. Furthermore, onset and continuation of diabetes reduced cell proliferation and neuroblast differentiation, and Al exposure amplified reduction of these parameters. These results suggest that Al exposure via drinking water aggravates the impairment in hippocampal neurogenesis that is typically observed in type 2 diabetic animals.

Effect of aluminum on antioxidant activity and phenolic compounds content in in vitro cultured blueberries / Efectos de aluminio en la capacidad antioxidante y en el contenido de compuestos fenólicos en plántulas de arándano cultivadas in vitro

Blueberry is a popular natural food product consumed worldwide. Acid soils are found throughout the world. A significant problem of acid soils is the active aluminum content, which may result toxic to plant. The present study was undertaken to assess the toxicities of Al for Blueberry (Vaccinium corymbosum L.) cultivated in vitro and treated with 100 and 200 uM Al. The effects of Al concentration on malondialdehyde (MDA) content, antioxidant activity and phenolic compounds of blueberry after 7, 14 and 21 days of treatment were established. The analysis of the MDA accumulated in the tissues of the blueberry seedlings indicates that Al concentration increases the damage caused by lipid peroxidation, for both treatments, after 14 days. The highest antioxidant activity in the extracts was observed at 200 uM Al after 14 days of treatment, being chlorogenic and ellagic acids the most significant metabolites involved in the antioxidant properties. Then, the content of Al in soil could be modulate the content of bioactive compounds in blueberry plants.

El Arándano es un popular alimento natural consumido en todo el mundo. Los suelos ácidos se encuentran en todo el mundo. Un problema significativo de suelos ácidos es el contenido de aluminio activo, que puede resultar tóxico para la planta. Este estudio se realizó para evaluar la toxicidad del aluminio en plantas de arandano, cultivadas in vitro y tratadas con 100 y 200 mM de Al. Se establecieron los del aluminio en el contenido de malodialdehido (MDA), capacidad antioxidante y contenido de compuestos fenolicos en plantulas de arandano luego de 7, 14 y 21 dias de tratamiento. El análisis del MDA acumulado en los tejidos de las plantulas de arándanos indica que la concentración de Al aumenta el daño causado medido como peroxidación de lípidos, para ambos tratamientos, después de 14 días. La actividad antioxidante más alta de los extractos se obseva a 200 mM de Al después de 14 días de tratamiento, siendo los ácidos clorogénico y elágico los metabolitos más importantes que participan en las propiedades antioxidantes. Entonces, el contenido de Al en el suelo podría modular el contenido de compuestos bioactivos en plantas de arándanos, alterando sus propiedades medicinales.

Aluminum and ethanol induce alterations in superoxide and peroxide handling capacity (SPHC) in frontal and temporal cortex.

Aluminum is an omnipresent neurotoxicant and has been associated with several neuropathological disorders. Cerebrum and cerebellum have been shown to face augmented oxidative stress when animals are exposed to aluminum and high doses of ethanol. To establish the link between oxidative stress and neurobehavioral alterations, the present study was conducted to determine the extent of oxidative stress in low levels of pro-oxidant (ethanol exposure) status of the functionally discrete regions of the cerebrum. Male Wistar rats were exposed to aluminum (10 mg/kg body wt) and ethanol (0.2-0.6 g/kg body wt) for 4 weeks. Spontaneous motor activity (SMA) and Rota-Rod performances (RRP) were recorded weekly during the period of exposure. At the end of 4th week, oxidative stress parameters were determined from the homogenized cerebral tissue. GSH-independent superoxide peroxide handling capacity (GI-SPHC) and GSH-dependent superoxide peroxide handling capacity (GD-SPHC) were determined for FC and TC upon exposure to ethanol in the absence and presence of aluminum exposure. Aluminum was found to augment the oxidative stress at higher doses (0.6 g Ethanol/kg body wt) of ethanol, particularly in FC. The SPHC of FC was also found to be compromised significantly in aluminum-ethanol co-exposed animals. It was concluded that even though the manifestation of oxidative stress was not observed as revealed by assaying the widely used oxidative stress biochemical markers (indices), aluminum and ethanol (low doses) exposure induced alterations in the handling capacity of oxidant imbalance that could be recognized by studying the SPHC of FC. Comparison of GD-SPHC and GI-SPHC offered a possible mechanism of compromised SPHC in FC. This observation is likely to offer insights into the mechanism of association between aluminium exposure and behavioral changes in neurodegenerative disorders towards therapeutic strategies for these disorders.

Effect of aluminum exposure on superoxide and peroxide handling capacities by liver, kidney, testis and temporal cortex in rat.

Oxidant imbalance is one of the causative mechanisms of aluminum-induced neurotoxicity. In this study, we investigated aluminum-induced oxidant imbalance in non-neuronal tissues (liver, kidney and testis) and temporal cortex in rats. The differences in adaptations to superoxide and peroxide handling capacities (SPHC) of studied organs due to aluminum insult were also evaluated. Male Wistar rats were exposed to aluminum (10 mg/Kg body wt/day) for 4 weeks through orogastric intubation. Liver showed significant decrease in reduced glutathione level, while significant alteration in lipid peroxidation was observed in temporal cortex in aluminium-exposed animals. Superoxide dismutase activity was significantly altered in liver and temporal cortex and catalase activity significantly reduced in the liver due to aluminum exposure, while glutathione reductase and glutathione peroxidase activities were altered in all the tested organs. Among the organs, glutathione-independent SPHC was relatively higher in liver and kidney, while glutathione-dependent SPHC was relatively higher in testis and temporal cortex. As compared to control, aluminum-exposed rats demonstrated reduction in glutathione-dependent SPHC in temporal cortex and increment of the same in testis, while increment in glutathione-independent SPHC was observed in liver. In conclusion, aluminum-induced alteration in oxidant handling capacity could be the cause of oxidative stress both in the neuronal and non-neuronal tissues.

Relação entre alumínio e silício em genótipos de milho resistente e sensível a toxidez de alumínio / Relation between aluminum and silicon in maize genotypes resistant and sensitive at aluminum toxicity

A fim de obter informações sobre a relação entre alumínio e silício no crescimento de dois genótipos de milho, sendo um tolerante e outro sensível a toxidez de alumínio, foi realizado um estudo em casa de vegetação, na presença e ausência de alumínio e silício em dois genótipos de milho. Os tratamentos utilizados foram uma solução de 2,0 mmol L-1 de cálcio (CaCl2), na presença e na ausência de alumínio (0,025 mmol L-1- AlCl3) e de silício (0,14 mmol L-1 a partir de uma solução de SiO2). O experimento foi conduzido por um período de cinco dias e no final foram avaliados o comprimento de raiz, as concentrações de silício, alumínio e cálcio na parte aérea e nas raízes e o índice mitótico de células meristemáticas das raízes. O silício reduziu o efeito tóxico do alumínio no crescimento radicular dos genótipos de milho independente da sensibilidade ao alumínio.

To verify the relation between aluminum and silicon in the growth of two maize genotypes resistant and sensitive at toxicity aluminum was carried out in the greenhouse a bioensaio involving the treatments presence and absence of aluminum and silicon in corn genotypes. The treatments were compound for solutions of 2.0 mmol L-1 calcium (CaCl2) without and with aluminum (0.025 mmol L-1 AlCl3) and silicon (0.14 mmol L-1, to part solution SiO2). The experiment was carried out for five days and for assess the treatments effect were evaluated root length, silicon, aluminum and calcium concentrations in the shoots and in the roots and the mitotic index of meristematic cells of roots. Silicon reduced the toxic effect of aluminum in corn genotypes as evaluated through root length.

Rúcula em cultivo hidropônico submetida em diferentes concentrações de alumínio / Eruca in hydroponics posted in different concentrations of aluminum

Objetivou-se avaliar os efeitos do alumínio em solução nutritiva, no crescimento de plantas de rúcula (Eruca sativa Mill.) em condições controladas. Utilizou-se tricloreto de alumínio, AlCl3, sendo os tratamentos: 0,0; 15,0; 30,0; 45,0 e 60,0 mg Al3+ L-1 de solução. As sementes de rúcula foram distribuídas em espuma fenólica onde receberam água destilada durante 10 dias após a semeadura (DAS) e após esse período as plântulas foram transferidas para vasos plásticos de capacidade de 2 kg com areia lavada e peneirada. Na omissão de alumínio (0,0 mg Al3+ L-1) o pH foi ajustado para 6,0. O experimento foi dividido em três etapas: 1) do 11º ao 14º DAS, as plantas foram irrigadas com solução completa diluída a 50% (pH 6,0); 2) do 15º ao 28º DAS, as plantas foram irrigadas com solução completa, modificada, com fósforo na concentração de 3,1 mg L-1 (pH 6,0); 3) do 29º ao 45º DAS, as plantas foram submetidas aos tratamentos com alumínio na solução nutritiva completa, modificada com concentração de fósforo de 3,1 mg L-1 e pH ajustado para 4,2. Aos 45 DAS foram avaliados: número de folhas, comprimento da parte aérea, das raízes e total, massa seca das raízes, das hastes e total além da área foliar. O delineamento experimental foi inteiramente casualizado com cinco repetições e os dados submetidos à análise de variância e estudo de regressão polinomial. O crescimento das plantas de rúcula é significativamente reduzido na presença do alumínio (AlCl3 ) em condições de solução nutritiva.

Aimed to evaluate the effects of aluminum in nutrient solution on growth of Eruca plants (Eruca sativa Mill.) under controlled conditions. We used aluminum trichloride, AlCl3, and the treatments: 0.0, 15.0, 30.0, 45.0 and 60.0 mg Al3 + L-1 solution. Eruca seeds were distributed phenolic foam which received distilled water for 10 days after sowing (DAS) and after this period the seedlings were transferred to plastic pots capacity of 2 kg washed sand and sieved. The omission of aluminum (Al3+ 0.0 mg L-1) the pH was adjusted to 6.0. The experiment was divided into three stages: 1) from 11 to the 14 DAS, the plants were irrigated with a solution diluted 50% (pH 6.0), 2) from 15 to 28 DAS, plants were irrigated with complete solution modified with phosphorus at a concentration of 3.1 mg L-1 (pH 6.0), 3) from 29 to the 45 DAS, the plants were treated with aluminum in the complete nutrient solution, modified with phosphorus concentration of 3,1 mg L-1 and pH adjusted to 4.2. At 45 DAS were evaluated: number of leaves, shoot length, root and total, dry mass of roots, stems and total leaf area as well. A completely randomized design with five replicates and the data submitted to analysis of variance and polynomial regression study. Plant growth rocket is significantly reduced in the presence of aluminum (AlCl3) under conditions.of.nutrient.solution

Mapping aluminum tolerance loci in cereals: a tool available for crop breeding

Aluminum (Al) toxicity is the main factor limiting crop productivity in acidic soils around the world. In cereals, this problem reduces crop yields by 30-40 percent. The use of DNA-based markers linked to phenotypic traits is an interesting alternative approach. Strategies such as molecular marker-assisted selection (MAS) in conjunction with bioinformatics-based tools such as graphical genotypes (GGT) have been important for confirming introgression of genes or genomic regions in cereals but also to reduce the time and cost of identifying them through genetic selection. These biotechnologies also make it possible to identify target genes or quantitative trait loci (QTL) that can be potentially used in similar crops to increase their productivity. This review presents the main advances in the genetic improvement of cereals for Al-tolerance.

Germination and vigor of lettuce seeds (Lactuca sativa L) pelleted with homeopathic preparations Alumina and Calcarea carbonica subjected to toxic levels of aluminum / Germinação e vigor de sementes de alface (lactuca sativa l) Peletizadas com as preparações homeopáticas alumina e calcarea carbonica expostas a níveis tóxicos de alumínio / Germinación y vigor de semillas de lechuga (lactuca sativa L) peletizadas con los preparados homeopáticos Alumina y Calcarea carbonica expuestas a niveles tóxicos de aluminio

Background: aluminum toxicity is the most important factor limiting the growth of plants in acid soils, whereas current treatments are unfeasible. For this reason, alternatives are sought for, among which homeopathic treatment. Aims: this study aimed at evaluating the influence of homeopathic preparations Alumina 6cH, Alumina 12cH, Calcarea carbonica 6cH and Calcarea carbonica 12cH on the germination and vigor of lettuce seeds subjected to toxic levels of aluminum in paper-solution. At the same time, it was sought to develop a new procedure to apply homeopathic preparations in plants (pelleting). Methods: the statistical design was entirely randomized (CRD) with 6 treatments and 4 repetitions. Treatments included: 1) pelleted seeds/talc + Alum 6 cH; 2) pelleted seeds/talc + Alum 12cH; 3) pelleted seed/talc + Calc 6cH; 4) pelleted seeds/talc + Calc 12cH; 5) pelleted seeds/talc + distilled water; 6) non pelleted seeds (control). Variables evaluated were: germination percentage (GP), germination speed index (GSI) and radicle length (RL). Results: there was significant difference in GSI and RL ? variables that reflect the vigor of seeds - between the samples treated with homeopathic preparations and the controls Conclusions: homeopathic preparations Alumina 6cH and 12cH and Calcarea carbonica 6cH and 12cH had significant effect on the vigor of lettuce seeds subjected to stress conditions.

Introdução: a toxicidade por alumínio é o principal fator que limita o crescimento das plantas em solos ácido; no entanto, os tratamentos disponíveis não são praticáveis. Por esse motivo, são procuradas alternativas, entre as quais, encontra-se a homeopatia. Objetivos: avaliar a influência das preparações homeopáticas Alumina 6cH e 12cH, e Calcarea carbonica 6cH e 12cH na germinação e vigor de sementes de alface expostas a níveis tóxicos de alumínio em papel-solução. Ao mesmo tempo, procurou-se desenvolver um novo método de aplicação de preparações homeopáticas nas plantas (peletização). Métodos: o desenho estatístico foi totalmente casualizado, com 6 tratamentos e 4 repetições. Os tratamentos incluíram: 1) sementes peletizadas/talco + Alum 6cH; 2) sementes peletizadas/talco + Alum cH12; 3) sementes peletizadas/talco + Calc 12cH; 4) sementes peletizadas/talco + Calc 12cH; 5) sementes peletizadas/talco + água destilada (controle 1) e 6) sementes não peletizadas. As variáveis avaliadas foram: porcentagem de germinação; índice de velocidade de germinação (IVG); e crescimento radicular (CR). Resultados: houve diferença significativa nas variáveis que refletem o vigor das sementes (IVG e CR) entre as amostradas tratadas com preparações homeopáticas e os controles. Conclusões: as preparações homeopáticas Alumina 6cH e 12cH, e Calcarea carbonica 6cH e 12cH apresentaram efeito significativamente positivo no vigor de sementes de alface expostas a condições de estresse.

Introducción: la toxicidad por aluminio es el factor más importante que limita el crecimiento de las plantas en suelos ácidos, mientras que los tratamientos disponibles son impracticables. Por eso, se buscan alternativas, entre ellas, la homeopatía. Objetivos: evaluar la influencia de los preparados homeopáticos Alumina 6cH y 12cH, y Calcarea carbonica 6cH y 12cH en la germinación y vigor de semillas de lechuga expuestas a niveles tóxicos de aluminio en papel-solución. Al mismo tiempo, se buscó desarrollar un nuevo método para aplicar preparados homeopáticos en plantas (peletización). Métodos: o diseño estadístico fue completamente casualizado, con 6 tratamientos y 4 repeticiones. Los tratamientos fueron: 1) semillas peletizadas/talco + Alum 6cH; 2) semillas peletizadas/talco + Alum cH12; 3) semillas peletizadas/talco + Calc 12cH; 4) semillas peletizadas/talco + Calc 12cH; 5) semillas peletizadas/talco + agua destilada (controle 1) e 6) semillas no peletizadas. Las variables evaluadas fueron: porcentaje de germinación (PG); índice de velocidad de germinación (IVG); y longitud de las radículas (LR). Resultados: hubo diferencia significativa en el IVG y LR ? que reflejan el vigor de las semillas ? entre las semillas tratadas con preparados homeopáticos y los controles. Conclusión: los preparados homeopáticos Alumina 6cH y 12cH, y Calcarea carbonica 6cH y 12cH manifestaron efectos estadísticamente significativos en el vigor de semillas de lechuga expuestas a condiciones de stress.

Molecular toxicity of aluminium in relation to neurodegeneration.

Exposure to high levels of aluminium (Al) leads to neurofibrillary degeneration and that Al concentration is increased in degenerating neurons in Alzheimer's disease (AD). Nevertheless, the role of Al in AD remains controversial and there is little proof directly interlinking Al to AD. The major problem in understanding Al toxicity is the complex Al speciation chemistry in biological systems. A new dimension is provided to show that Al-maltolate treated aged rabbits can be used as a suitable animal model for understanding the pathology in AD. The intracisternal injection of Al-maltolate into aged New Zealand white rabbits results in pathology that mimics several of the neuropathological, biochemical and behavioural changes as observed in AD. The neurodegenerative effects include the formation of intraneuronal neurofilamentous aggregates that are tau positive, oxidative stress and apoptosis. The present review discusses the role of Al and use of Al-treated aged rabbit as a suitable animal model to understand AD pathogenesis.

Comparative genomics of grasses tolerant to aluminum

The family Poaceae includes over 10,000 species, among which are the most economically important cereals: maize, sorghum, rice, wheat, rye, barley, and oat. These cereals are very important components of human and animal food. Although divergence of the members of this family occurred about 40 million years ago, comparative genome analyses demonstrated that gene orders among species of this family remain largely conserved, which can be very useful for understanding their roles and evolution. Even with an intricate evolutionary history in which chromosome fragments, losses and duplications have to be considered at the ploidy level, grasses present a genetic model system for comparative genomics. The availability of mapped molecular markers, rice genome sequences and BAC and EST libraries from several grass species, such as rice, wheat, sorghum, and maize, facilitates biology and phylogeny studies of this group. The value of using information from different species in modern plant genetics is unquestionable, especially in the study of traits such as tolerance to aluminum in soils, which affects plant growth and development. Comparative genomic approaches to aluminum tolerance can identify genomic regions and genes responsible for aluminum tolerance in grasses.

Absorcão de P, Mg, Ca e K e tolerância de genótipos de arroz submetidos a estresse por alumínio em sistemas hidropônicos / Nutrient absorption in aluminum stressed rice plants under hydroponic culture

Solos com concentracões elevadas de alumínio (Al3+), podem prejudicar o desenvolvimento e a absorcão de nutrientes de plantas de arroz. O objetivo do experimento foi avaliar o desempenho de dezoito genótipos de arroz quanto a absorcão de P, Mg, Ca e K e identificar genótipos com bom desempenho quando submetidos ao estresse por Al3+ em sistema hidropônico. Foram utilizados quatro níveis de Al3+ (0, 10, 20 e 30mg L-1) e o delineamento experimental foi blocos casualizados com três repeticões. As plântulas permaneceram em sistema hidropônico por 20 dias sob efeito dos tratamentos, e após foram avaliadas quanto ao comprimento de raízes (CR) e teores de P, Mg, Ca e K. Todas as variáveis apresentaram reducões significativas nos seus valores, e os genótipos apresentaram diferentes desempenhos na absorcão de nutrientes frente aos tratamentos, com excecão do nutriente Mg que apresentou mesma resposta para todos os genótipos avaliados. Baseado na variável CR, os genótipos Felune e Taim foram considerados como mais tolerante e sensível ao Al3+, respectivamente. Para absorcão de nutrientes, os genótipos apresentaram comportamentos muito diferenciais para cada elemento avaliado, sendo que também o genótipo Felune obteve elevados índices de absorcão. Todas as variáveis revelaram correlacões significativas entre si.

Aluminium toxicity induced poikilocytosis in an air-breathing teleost, Clarias batrachus (Linn.).

The present study was undertaken to assess the toxicity of acid alone and two different sublethal concentrations of aluminium, (25% and 75% dose of 96 hr LC50 value in acidified soft water of pH 5) on red blood cells of a stenohaline catfish, C. batrachus for an acute exposure of 5 days. The scanning electron microscopic studies on all the three treated groups revealed several kinds of erythrocyte alterations and modifications with abnormal morphology. These included abnormal surface-wrinkling accompanied with excessive roughness on the membrane, erythrocytes with surface granulation in higher dose and finally the appearance of morphologically abnormal forms, the codocyte (target cell) and the stomatocyte. The results suggest that abnormality in the shape of erythrocytes could be linked to altered surface membrane area to volume ratio, decrease in cytoplasmic volume owing to reduced Hb content or increase in the amount of water content within the cell resulting from osmotic disequilibrium. In this context, the abnormal surface membrane morphology could be attributed to cytoskeleton fragility and defects in structural proteins. Further, the acid group exhibited a striking behavior of cellular adhesion and bonding to adjoining cell surfaces, culminating in several bunches which thereby reduces the surface area for gaseous exchange and could produce blocking effect while flowing through microcirculation.

Effect of aluminum and chromium on the germination and growth of two Vigna species

The study deals with the effect of metal toxicity [aluminum, chromium and combination of both the metals] on seed germination, root length, shoot length, seedling length and dry biomass of Vigna radiata and V. sinensis. Chromium adversely affected the seedling by significantly reducing the growth whereas aluminum did not show such effect in both the species. Percentage of germination was good in both the species at different concentration of treatment [aluminum, chromium and combined treatment]. Shoot length was also not much affected in V. sinensis as it was greatly inhibited in V. radiata. Both the species showed the purpling of stem. Dry biomass of V. radiata showed positive effect than V. sinensis. However, dry biomass decreased to a lesser extent when treated with aluminum, chromium and combined treatment as compared to control