Aluminum speciation studies in biological fluids. Part 7. A quantitative investigation of aluminum(III)-malate complex equilibria and their potential implications for aluminum metabolism and toxicity

Evaluation of L-carnitine's protective properties against AlCl3-induced brain, liver, and renal toxicity in rats

A common heavy metal in many facets of daily life is aluminum (AlCl3), which can be found in food, toothpaste, cosmetics, food additives, and numerous pharmaceutical items. The hippocampus, liver, and kidneys have the highest concentrations of this powerful neurotoxin, which also accumulates over time and contributes to the development of a number of cognitive disorders. Long-term overconsumption of AlCl3 results in hepatic and renal toxicity as well as neuronal inflammation. The purpose of the research is to assess the potential protective effects of various L-carnitine dosages as an antioxidant against hebato, renal, and neuronal toxicity in rats caused by aluminum chloride (AlCl3) (20 mg/kg, 1/20 LD 50). Six groups (n = 6), consisting of 36 adult albino rats, were randomly assigned. Saline was administered to the control group (GI) by injection. (GII) had given an injection of L-carnitine at a low-dose of 75 mg/kg body weight. An injections of L-carnitine at a high-dose (150 mg/kg) were given to (GIII), and AlCl3 (20 mg/kg) was given to (GIV). (GV) administered with L-carnitine (75 mg/kg) and AlCl3 (20 mg/kg) by injection. For 60 days, AlCl3 (20 mg/kg) and L-carnitine (150 mg/kg) were administered to GVI by injection. Furthermore, the histological structure of the cortex, hippocampus, and hepatic renal tissues appeared to change in response to AlCl3. L-carnitine therapy lessened the negative effects of AlCl3. The observable improvement in the tissues of the brain, liver, and kidneys further supported this histopathologically. It is possible to draw the conclusion that L-carnitine holds promise as a corrective measure for AlCl3, which causes renal toxicity and neural hepatotoxicity in rats. When it comes to adult albino rats, L-carnitine has a negative impact and exhibits ameliorative effects against aluminum chloride.

Hydroxy-Carboxylic Acids as Green and Abundant Ligands for Sustainable Recovery of Copper from a Multimetallic Powder: A Proof of Concept

The recovery of copper and other valuable metals had become increasingly strategic for the future of the global economy, particularly in regions lacking abundant mineral resources, such as most European countries. In this study, we investigated the viability of utilizing environmentally friendly, cost-effective, abundant and bio-based ligands, specifically carboxylic acids and their derivatives, for copper leaching in a low-temperature hydrometallurgical process. Our investigation focused on elucidating the impact of substituents in the α position of hydroxy-carboxylic acids on copper solubilization efficacy. Notably, hydroxy-carboxylic acids, like malic acid and lactic acid, were evidenced as particularly promising ligands for leaching copper from a custom-made multimetallic powder. By thoroughly characterizing the obtained complexes (Raman, UV-Vis) and by supporting the experimental efforts by a Design of Experiment (DoE) approach, we optimized the leaching process. The influence of experimental parameters such as pH, temperature, leaching time, and Cu/ligand molar ratio on process yield (determined through Inductively Coupled Plasma - Optical Emission Spectroscopy, ICP-OES, analysis) was thoroughly investigated. Additionally, we developed a subsequent copper recovery step by precipitating copper (II) hydroxide in an alkaline environment, guided by speciation diagrams tailored for each copper-ligand system.

Antioxidant Property of the Egyptian Propolis Extract Versus Aluminum Silicate Intoxication on a Rat's Lung: Histopathological Studies

In this study, we evaluated the inflammatory responses induced by aluminum silicate (AS) cytotoxicity in rat lungs. The prophylactic effect of propolis extract was evaluated in 60 adult male albino rats. The rats were divided into six groups: (1) a normal, healthy control group; (2) a normal group fed with 200 mL of propolis extract/Kg; (3) a low-dose positive control group injected with 5 mg/kg of AS; (4) a treated group given propolis and a low dose of AS; (5) a high-dose positive control group injected with 20 mg/kg of AS; and (6) a treated group given propolis with a high-dose of AS. At the end of the two-month experiment, the rats’ lungs were removed. For each pair of lungs, one portion was subjected to biochemical analysis and the other underwent hematoxylin and eosin (H&E) staining in order to study its histology. The rats that received AS doses displayed significant disorders in their antioxidant contents as well as in their enzymatic activities and their histopathological structures revealed severe damage to their lung tissues. Upon the rats being treated with propolis, the enzymatic and antioxidant contents improved and partial improvements in the lung structures appeared, including minimized congestion, a reduced hemorrhage of blood vessels and preserved bronchioles, alveolar ducts, and alveoli. The prophylactic effectiveness of propolis extract on the cytotoxicity of AS, owing to the antioxidant properties of propolis, were studied.

Sulforaphane response on aluminum-induced oxidative stress, alterations in sperm characterization and testicular histomorphometry in Wistar rats

Background

The exposure of male individual to environmental toxicant is regarded as a channel that results in reduced sperm counts and infertility.

Objective

This study investigated the ameliorative response of Sulforaphane (SFN) on Aluminum trichloride (AlCl3) induced testicular toxicity in adult male Wistar rats.

Materials and Methods

A total of 32 adult male Wistar rats (180-200 gm between 8-10 wk) were divided into four groups (n = 8/each). Group A) received distilled water orally as placebo; Group B) received 100 mg/kgbw AlCl3 only orally; Group C) received 100 mg/kgbw AlCl3 and 100 mg/kgbw SFN orally; and Group D) received 100 mg/kgbw SFN only orally. After 28 days of experiment, animals underwent cervical dislocation, blood serum was obtained for analysis, and testes were harvested for biochemical assays, histology, hormonal profile, and sperm characterization.

Results

The sperm parameters showed a significant difference within the AlCl3 only group compared with the control and SFN only groups (p = 0.02). However, AlCl3 and SFN co-treatment showed improvement in the motility, viability, and sperm count compared with the AlCl3 only group (p = 0.02). Furthermore, there was a significant decline in the levels of hormones profile and antioxidant status in AlCl3 only group compared to the control and SFN only (p = 0.02). The testicular histoarchitecture of the AlCl3 only group showed shrinkage of seminiferous tubules, spermatogenesis disruption, and empty lumen compared to the control and SFN only groups.

Conclusion

The present study revealed the ameliorative response of SFN on AlCl3-induced testicular toxicity on serum hormone profiles, antioxidant status, lipid peroxidation, and histomorphometric analysis through oxidative stress.

Towards Self-Organized Anodization of Aluminum in Malic Acid Solutions-New Aspects of Anodization in the Organic Acid

In this work, aluminum (Al) anodization in malic acid electrolytes of different concentrations (0.15 M, 0.25 M, and 0.5 M) was studied. The close-packed hexagonal pore structure was obtained for the first time in this organic acid in a 0.5 M solution, at 250 V and temperature of 5 °C. Moreover, the process was investigated as a function of the number of cycles carried out in the same electrolyte. A repetition of anodization under seemingly the same external electrochemical parameters (applied voltage, temperature, etc.) induced serious changes in the electrolyte. The changes were reflected in the current density vs. time curves and were most evident in the higher concentrated electrolytes. This phenomenon was tentatively explained by a massive incorporation of malate anions into anodic alumina (AAO) framework. The impoverishment of the electrolyte of the malate anions changed internal electrochemical conditions making easier the attraction of the anions to the Al anode and thus the AAO formation. The electrolyte modification was advantageous in terms of pore organization: In a 0.25 M solution, already after the second anodization, the pore arrangement transformed from irregular towards regular, hexagonal close-packed structure. To the best of our knowledge, this is the first observation of this kind.

Impacts of Egyptian propolis extract on rat cerebellum intoxicated by aluminum silicate: histopathological studies

Human is exposed to traces of aluminum silicate (AlS), i.e., cosmetics, pesticides. Accumulation of aluminum compounds including AlS is associated with neuropathological diseases, e.g., Alzheimer's disease. The aim of the current study is to investigate the neuroprotective effects of propolis extracts in AlS-induced cerebellum intoxication in rats. Forty adult rats were randomly divided into four groups (n = 10). The first group served as a control; the second group treated with 200 ml propolis/kg bwt. every other day by stomach gavage tube, third group was intraperitoneally injected with AIS (20 mg/kg) twice a week for 8 weeks, and the fourth group received propolis extract and AIS. At the end of 8 weeks, the cerebellum was harvested for further ultrastructure, histological, and histochemical investigations. Using electron microscopy, the ultrastructure of the cerebellar cortex of AlS intoxicated rats showed Purkinje cells with an irregular euchromatic nucleus and extremely increased invagination of the nuclear envelope. In addition, the cytoplasm revealed numerous damaged mitochondria (> 20%) as well as swollen lysosomes (> 40%) compared to controls. These AlS-related ultrastructure changes were to some extent normalized to < 10% and < 30% in case of mitochondria and lysosomes, respectively, if rats were co-treated with propolis extract. Further, histopathological examination showed that AlS-exposed rats revealed abnormal Purkinje cells with irregular size and shrank shape, evidence of pre-necrotic stage in the form of nuclear pyknosis, and condensed and frequent darkly stained cells in cerebellar layers. However, propolis extract co-administration reversed from 35 to 25% (p < 0.05) these alterations. The carbohydrate and protein contents were reduced in case of AlS treatment and surprisingly propolis co-treatment was able to rescue these neurotoxic effects. Propolis extract might have neuroprotective effects against AIS-induced toxicity. Further studies are required to identify the mechanism of the pharmacological action and optimal settings for medical testing of propolis extract.

Evaluation of Dewatering Performance and Fractal Characteristics of Alum Sludge

The dewatering performance and fractal characteristics of alum sludge from a drinking-water treatment plant were investigated in this study. Variations in residual turbidity of supernatant, dry solid content (DS), specific resistance to filtration (SRF), floc size, fractal dimension, and zeta potential were analyzed. Sludge dewatering efficiency was evaluated by measuring both DS and SRF. Results showed that the optimum sludge dewatering efficiency was achieved at 16 mg∙L(-1) flocculant dosage and pH 7. Under these conditions, the maximum DS was 54.6%, and the minimum SRF was 0.61 × 10(10) m∙kg(-1). Floc-size measurements demonstrated that high flocculant dosage significantly improved floc size. Correlation analysis further revealed a strong correlation between fractal dimension and floc size after flocculation. A strong correlation also existed between floc size and zeta potential, and flocculants with a higher cationic degree had a larger correlation coefficient between floc size and zeta potential. In the flocculation process, the main flocculation mechanisms involved adsorption bridging under an acidic condition, and a combination between charge neutralization and adsorption-bridging interaction under neutral and alkaline conditions.

A novel sensitive fluorescent turn-on probe for rapid detection of Al3+ and bioimaging

The first simply-structured rhodamine based probe L for the detection of Al³⁺ applied in water solution and live-cell imaging of HeLa cells without toxicity.

Role of propolis (bee glue) in improving histopathological changes of the kidney of rat treated with aluminum chloride

Humans are frequently exposed to aluminum from various food additives, therapeutic treatments and the environment, and it can be potentially toxic. This study is aimed to elucidate the protective effects of propolis against aluminum chloride (AlCl3 )-induced histopathological and immunohistochemical changes in kidney tissues of rats. Sixty Wistar Albino male rats (average weight 250-300 g) were divided into three equal groups. The first served as a negative control. The second received AlCl₃ (34 mg/kg bw, 1/ 25 LD 50). The third were administered AlCl₃ (34 mg/kg bw, 1/ 25 LD 50) plus propolis (50 mg/kg bw). Doses were given once daily via a gavage for 8 weeks every day. The results showed that shrunken glomeruli, intraglomerular congestion, loss of apical microvilli, degeneration of mitochondria and widened rough endoplasmic reticulum were also observed in the Proximal Convoluted Tubules of these animals. Treatment with propolis ameliorated the harmful effects of AlCl₃ ; this was also proved histopathologically by the noticeable improvement in the renal tissues. There were also significant variations in the expressed of ki-67 and p53 proteins. It can be concluded that propolis may be promising as a natural therapeutic agent in AlCl₃ -induced renal toxicity and oxidative stress in rat kidneys.

Protective effects of desferrioxamine and deferiprone on the spleen tissue of aluminum intoxicated mice: A Fourier transform infrared spectroscopy study

The present study was designed to examine the protective effects of the chelating agents desferrioxamine (DFO) and deferiprone (DFP) in aluminum intoxicated spleen tissue of mice by Fourier transform infrared (FTIR) spectroscopy. The finding revealed the alterations on the major biochemical constituents, such as lipids, proteins, phosphodiester and nucleic acids of the spleen tissue of mice at molecular level. The significant decreased in the peak areas of asymmetric and symmetric mode of the phosphodiester groups from control to aluminum intoxicated, but improved it by DFP and DFO+DFP treatments respectively for nearer control value. The bands ratio at I1081/I1232 significantly decreased from control to aluminum, but enhanced it by DFP and DFO+DFP respectively. This result suggests that DFO and DFP are the phosphodiesterase inhibitor, recovered from chronic growth of diseases in the spleen. Amide I and amide II peak area values decreased from control to aluminum intoxicated spleen tissue, but treated with DFP and DFO+DFP significantly improved. This result suggests an alteration in the protein profile. The absence of Olefinic=CH stretching in aluminum intoxicated spleen suggests an altered lipid levels. Concentrations of trace elements were found by ICP-OES. Histopathological findings confirmed the biochemical observations of this study. The results of the FTIR study were found to be in agreement with biochemical studies and demonstrated that FTIR can be used successfully applied to toxicological studies at molecular level.

A selective, cell-permeable fluorescent probe for Al3+ in living cells

The synthesis and evaluation of a novel Schiff-base fluorescent probe L for detection of Al(3+) are described. The structure of L was determined by X-ray and other spectroscopic data. The fluorescent spectra changes and microscopy images show that indicator L is highly selective for Al(3+) not only in abiotic systems but also in living cells. Other metal ions failed to respond. The new probe could be used as an efficient tool for Al(3+) monitoring in the environment and biological systems.

Separation and characterization of aluminium malate species by ion chromatography

Aluminium malate complexes have a high relevance in biological systems. The anionic species present in an aqueous aluminium malate mixture can be investigated by ion chromatography coupled online with inductively coupled plasma atomic emission spectroscopy. As malic acid is a chiral ligand, the experiments were carried out using the racemic and the enantiopure forms. In both systems four anionic complexes are observable in the model solutions. One of two crystallized and well-characterized anions, [Al(4)Malate(6)](6-) and [Al(4)Malate(4)](2-), serves as a reference anion for the assignment of one of the species occurring in the model solutions. The main species in the enantiopure aluminium malate model with biological relevance over a wide pH range is the [Al(4)Malate(4)](2-) anion. The [Al(4)Malate(6)](6-) anion is not present in the racemic model solution. This anion suffers complete species disintegration after dissolution. The kinetics of the decay is first order and the activation energy of the decomposition is 74 kJ/mol. A retention model for ion chromatography was used for the determination of the effective charges of the species. The effective charge obtained by the retention model was calibrated in relation to nominal charges of the anions by using several well-defined and differently charged anions and anionic aluminium species.

Aluminum is a potential environmental factor for Crohn's disease induction: extended hypothesis

Aluminum (Al) is a common environmental compound with immune-adjuvant activity and granulomatous inflammation inducer. Al exposure in food, additives, air, pharmaceuticals, and water pollution is ubiquitous in Western culture. Crohn's disease (CD) is a chronic relapsing intestinal inflammation in genetically susceptible individuals and is influenced by yet unidentified environmental factors. It is hypothesized, in the present review, that Al is a potential factor for induction or maintaining the inflammation in CD. Epidemiologically, CD incidence is higher in urban areas, where microparticle pollution is prevalent. Al immune activities share many characteristics with the immune pathology of CD: increased antigen presentation and APCs activation, many luminal bacterial or dietary compounds can be adsorbed to the metal and induce Th1 profile activity, promotion of humoral and cellular immune responses, proinflammatory, apoptotic, oxidative activity, and stress-related molecule expression enhancement, affecting intestinal bacterial composition and virulence, granuloma formation, colitis induction in an animal model of CD, and terminal ileum uptake. The Al-bacterial interaction, the microparticles homing the intestine together with the extensive immune activity, put Al as a potential environmental candidate for CD induction and maintenance.

Characterization of the malate-aluminum(III) complex using 1H and 27Al NMR spectroscopy

Structural elucidation of a malate-aluminum(III) complex has been carried out using 1H and 27Al NMR spectroscopy. The 1H chemical shift perturbation clearly indicated the interaction between malate and Al(III) ion. The measurements of 27Al NMR and 1H-13C HSQC spectra demonstrated that the major form of a complex comprised two equivalent malate ions and two unequivalent Al(III) ions. With this constraint, an equilibrium geometry of the complex was proposed by a semi-empirical molecular orbital calculation.

Impact of aluminum on the oxidation of lipids and enzymatic lipolysis in monomolecular films at the air/water interface

There is evidence that serious pathologies are associated with aluminum (Al). In the present work, the influence of Al on enzymatic lipolysis was studied with the aim to get more insight into the possible link between the Al-induced membrane modification and the cytotoxicity of the trivalent cation (AlIII). Lipid monolayers were used as model membranes. The monomolecular film technique allowed monitoring the Al-dependent modifications of the lipid monolayer properties and enzyme kinetics. Two enzymes, namely, Candida rugosa lipase and a calcium (CaII)-dependent phospholipase A2 from porcine pancreas, were used to catalyze the lipolysis of triglyceride and phosphoglyceride monolayers, respectively. The results obtained show that Al modifies both the monolayer structure and enzymatic reaction rates. While the enzymes used in this study can be considered as probes detecting lipid membrane properties, it cannot be excluded that in physiological conditions modulation of the enzyme action by the Al-bound membranes is among the reasons for Al toxicity.

Spectroscopic characterization of 2-isopropylmalic acid–aluminum(III) complex

Spectroscopic elucidation of a 2-isopropylmalic acid (2-iPMA)-aluminum(III) complex has been carried out using (1)H, (13)C and (27)Al NMR spectroscopy, diffusion-ordered NMR spectroscopy (DOSY) and electrospray ionization mass spectrometry (ESI-MS). 2-iPMA is secreted by Saccharomyces cerevisiae and can dissolve Al(III) in the culture medium. The (1)H chemical shift perturbation and (1)H DOSY clearly indicated the formation of the 2-iPMA-Al(III) complex. The measurements of (13)C and (27)Al NMR spectroscopy and ESI-MS demonstrated that the major form of a complex is comprised four 2-iPMA and two Al(III) species. This compound is expected to possess strong Al(III)-detoxification capability.

Flavonoids in flowers of 16 Kalanchoë blossfeldiana varieties

Kalanchoë blossfeldiana varieties with orange, pink, red and magenta flowers were found to contain 3,5-O-beta-D-diglucosides of pelargonidin, cyanidin, peonidin, delphinidin, petunidin and malvidin. Pink, red and magenta varieties contained relatively high amounts of quercetin based flavonols. Four distinct quercetin flavonols were identified, namely quercetin 3-O-beta-D-glucoside and three that were quercetin 3-O-alpha-L-rhamnoside based, with either glucose, xylose or arabinose attached to position 2 of the rhamnose. In addition, the presence of at least three kaempferol based diglycosides was suggested from LC-MS analyses. Orange varieties contained very low amounts of flavonol co-pigments and of delphinidin derivatives. The flower extracts of the varieties 'Diva' (magenta) and 'Molly' (red) had identical anthocyanin ratios but differed significantly in flavonol content. The magenta variety contained four times as much quercetin relative to anthocyanidin as the red variety. This difference was mainly due to a larger content of quercetin 3-O-(2''-O-beta-D-glucopyranosyl-alpha-L-rhamnopyranoside). Based on pigment and co-pigment analyses, approaches for molecular breeding towards blue flower colour are discussed.

Application of spectral decomposition analysis to in vivo quantification of aluminum by neutron activation analysis

The toxic effects of aluminum are cumulative and result in painful forms of renal osteodystrophy, most notably adynamic bone disease and osteomalacia, but also other forms of disease. The Trace Element Group at McMaster University has developed an accelerator-based in vivo procedure for detecting aluminum body burden by neutron activation analysis (NAA). Further refining of the method was necessary for increasing its sensitivity. In this context, the present study proposes an improved algorithm for data analysis, based on spectral decomposition. A new minimum detectable limit (MDL) of (0.7+/-0.1)mg Al was reached for a local dose of (20+/-1)mSv. The study also addresses the feasibility of a new data acquisition technique, the electronic rejection of the coincident events detected by a NaI(Tl) system. It is expected that the application of this technique, together with spectral decomposition analysis, would provide an acceptable MDL for the method to be valuable in a clinical setting.

Kohl (surma): a toxic traditional eye cosmetic study in Saudi Arabia

The use of kohl (surma) as eyeliner is a popular practice in Saudi Arabia and people firmly believe that it is safe to use. A total of 107 kohl samples (branded and unbranded) were collected from different regions of Saudi Arabia, and analysed for the presence of lead. In addition, aluminium and antimony levels were also determined. Lead levels up to 53% were detected in some kohl preparations, and some samples were found to contain camphor and menthol. The blood analyses of regular kohl users revealed a high lead concentration and relatively low haemoglobin levels. Due to the health risk, an official public awareness campaign is suggested to encourage the use of lead-free kohl.

Contemporary understanding and management of reflux and constipation in the general population and pregnancy: a consensus meeting

BACKGROUND

Gastro-oesophageal reflux disease (GERD) and constipation have a major impact on public health; however, the wide variety of treatment options presents difficulties for recommending therapy. Lack of definitive guidelines in pharmacy and general practice medicine further exacerbates the decision dilemma.

AIMS

To address these issues, a panel of experts discussed the principles and practice of treating GERD and constipation in the general population and in pregnancy, with the aim of developing respective treatment guidelines.

RESULTS

The panel recommended antacids 'on-demand' as the first-line over-the-counter treatment in reflux, and as rescue medication for immediate relief when reflux breaks through with proton pump inhibitors. Calcium/magnesium-based antacids were recommended as the treatment of choice for pregnant women because of their good safety profile. In constipation, current data do not distinguish a hierarchy between polyethylene glycol (PEG)-based laxatives and other first-line treatments, although limitations are associated with stimulant- and bulk-forming laxatives. Where data are available, PEG is superior to lactulose in terms of efficacy. In pregnancy, PEG-based laxatives meet the criteria for the ideal treatment.

CONCLUSIONS

The experts developed algorithms that present healthcare professionals with clear treatment options and management strategies for GERD and constipation in pharmacy and general practice medicine.

Aluminum: impacts and disease

Aluminum is the most widely distributed metal in the environment and is extensively used in modern daily life. Aluminum enters into the body from the environment and from diet and medication. However, there is no known physiological role for aluminum within the body and hence this metal may produce adverse physiological effects. The impact of aluminum on neural tissues is well reported but studies on extraneural tissues are not well summarized. In this review, the impacts of aluminum on humans and its impact on major physiological systems are summarized and discussed. The neuropathologies associated with high brain aluminum levels, including structural, biochemical, and neurobehavioral changes, have been summarized. In addition, the impact of aluminum on the musculoskeletal system, respiratory system, cardiovascular system, hepatobiliary system, endocrine system, urinary system, and reproductive system are discussed.