Mineral status and superoxide dismutase enzyme activity in Alzheimer's disease

Natural Antioxidant Evaluation: A Review of Detection Methods

Antioxidants have drawn the attention of the scientific community due to being related to the prevention of various degenerative diseases. The antioxidant capacity has been extensively studied in vitro, and different methods have been used to assess its activity. However, the main issues related to studying natural antioxidants are evaluating whether these antioxidants demonstrate a key role in the biological system and assessing their bioavailability in the organism. The majority of outcomes in the literature are controversial due to a lack of method standardization and their proper application. Therefore, this study aims to compile the main issues concerning the natural antioxidant field of study, comparing the most common in vitro methods to evaluate the antioxidant activity of natural compounds, demonstrating the antioxidant activity in biological systems and the role of the main antioxidant enzymes of redox cellular signaling and explaining how the bioavailability of bioactive compounds is evaluated in animal models and human clinical trials.

Brief Review of Endometriosis and the Role of Trace Elements

Endometriosis is a chronic, estrogen-dependent, inflammatory condition that is defined as the presence of endometrial glands and stroma outside the uterine cavity. Despite the progress in research into the mechanisms leading to the development of endometriosis, its cause has not yet been established. It seems to be possible that the formation of oxidative stress may be one of the main causes of the development of endometriosis. There is much research that studies the potential role of trace elements in the appearance of endometrial-like lesions. Most studies focus on assessing the content of selected trace elements in the blood, urine, or peritoneal fluid in women with endometriosis. Meanwhile, little is known about the content of these elements in endometrial-like implants, which may be helpful in developing the theory of endometriosis. Investigations that are more comprehensive are needed to confirm a hypothesis that some trace elements play a role in the pathomechanism of endometriosis.

Study on the Molecular Mechanisms Against Human Breast Cancer from Insight of Elemental Distribution in Tissue Based on Laser-Induced Breakdown Spectroscopy (LIBS)

The role of elements in physiological and pathological metabolic processes remains an unmet challenge in biomedical research and clinical applications. Herein, a visual elemental imaging of tumor tissue platform of a laser-induced breakdown spectroscopy (LIBS) was developed to initially understand anti-tumor mechanisms. The relative enrichment degree and heterogeneous spatial distributions of four elements (calcium, sodium, copper, and magnesium) of tumor tissue from different treated could be easy to visualize. In particular, significant differences in the distribution of elements were observed in tumor tissue from drug-loading complex (hydrogel/DOX) treatment group. Correspondingly, the analysis of histopathological morphology showed that the morphology and density of tumor tissue in hydrogel/DOX treatment group changed obviously by using hematoxylin and eosin (H&E) staining assay, meanwhile cleaved caspase-3 (caspase-3) and tumor necrosis factor (TNF-α) were expressed at high levels tumors tissue in hydrogel/DOX treatment group by using immunohistochemical (IHC) staining. These results would endow different biological elements with incredible potential to study the mechanisms of anti-tumor, which opens new direction and perspectives for the multi-elemental mapping of biological tissues, especially in clinic application. The integrated platform of DNA nanohydrogel drug carrier-based anti-tumor treatment combined with LIBS elemental imaging, via tail intravenous injection of saline, hydrogel, DOX, and hydrogel/DOX in breast cancer xenograft tumor mice. (A) The workflow is outlined starting from nanohydrogel drug carrier-based anti-tumor treatment. (B) Schematic diagram of LIBS imaging platform.

Dietary Habits, Selenium, Copper, Zinc and Total Antioxidant Status in Serum in Relation to Cognitive Functions of Patients with Alzheimer's Disease

Oxidative stress plays a crucial role in the neurodegenerative process and can impair cognitive functions. In the prevention of Alzheimer's disease (AD), an adequate consumption of dietary antioxidants may be a major factor. The objective of the study was to estimate selenium (Se), copper (Cu), zinc (Zn), and total antioxidant status (TAS) in the serum of patients with AD in relation to their cognitive functions and dietary habits. A total of 110 patients (aged 54-93 years) with early or moderate AD, as well as 60 healthy people (aged 52-83 years) were studied. The severity of the disease was assessed using the mini-mental state examination (MMSE) scale. Food-frequency questionnaires were implemented to collect the dietary data. The concentrations of Se, Cu and Zn in the sera were determined by the atomic absorption spectrometry method. TAS was estimated spectrophotometrically using ready-made kits (Randox). Significantly lower concentrations of Se, Zn and TAS, and higher Cu:Zn ratio in the serum of patients with AD, compared to healthy people, were observed. A low correlation between the MMSE score and TAS in the serum of AD patients and significantly higher MMSE values in patients with TAS above the reference range were also noted. In patients with serum Cu concentration above the norm, significantly lower MMSE values were found. Selected dietary habits such as the frequency of consumption of various food products had a significant impact on the concentration of the assessed parameters in the serum of people with AD.

Proteomics Analysis of CA1 Region of the Hippocampus in Pre-, Progression and Pathological Stages in a Mouse Model of the Alzheimer's Disease

BACKGROUND

CA1 subregion of the hippocampal formation is one of the primarily affected structures in AD, yet not much is known about proteome alterations in the extracellular milieu of this region.

OBJECTIVE

In this study, we aimed to identify the protein expression alterations throughout the pre-pathological, progression and pathological stages of AD mouse model.

METHODS

The CA1 region perfusates were collected by in-vivo intracerebral push-pull perfusion from transgenic 5XFAD mice and their non-transgenic littermates at 3, 6 and 12 wereβmonths of age. Morris water maze test and immunohistochemistry staining of A performed to determine the stages of the disease in this mouse model. The protein expression differences were analyzed by label-free shotgun proteomics analysis.

RESULTS

A total of 251, 213 and 238 proteins were identified in samples obtained from CA1 regions of mice at 3, 6 and 12 months of age, respectively. Of these, 68, 41 and 33 proteins showed statistical significance. Pathway analysis based on the unique and common proteins within the groups revealed that several pathways are dysregulated during different stages of AD. The alterations in glucose and lipid metabolisms respectively in pre-pathologic and progression stages of the disease, lead to imbalances in ROS production via diminished SOD level and impairment of neuronal integrity.

CONCLUSION

We conclude that CA1 region-specific proteomic analysis of hippocampal degeneration may be useful in identifying the earliest as well as progressional changes that are associated with Alzheimer's disease.

Serum concentrations of heavy metals in women with endometrial polyps

Endometrial polyps are one of the common reasons of abnormal uterine bleeding in women. Industrialisation, urbanisation and increased air pollution cause increased heavy metal exposure. Heavy metals that have oestrogenic effects in human body are named as metalloestrogens. The aim of this study was to investigate the serum metalloestrogen levels such as copper (Cu), zinc (Zn), aluminium (Al), lead (Pb), nickel (Ni) and Cu/Zn ratio and their possible relationship with the occurrence of endometrial polyps. Eighty women with abnormal uterine bleeding were divided into two groups: 40 women diagnosed with endometrial polyp (study group) and 40 women without endometrial polyp (control group). Ages, body mass indices, smoking behaviours, drinking water choices, chronic diseases and intrauterine device histories were noted for all patients. Blood levels of Cu, Zn, Al, Pb, Ni and Cu/Zn ratio were analysed by inductively coupled plasma-mass spectrometry method for both groups. No statistically significant differences were observed in terms of serum median levels of Cu and Pb between the study and the control groups. The serum median levels of Zn, Ni and Al were found to be statistically lower in the study group when compared with the control group. The Cu/Zn ratio was statistically higher in the study group. High Cu/Zn ratio, as a biomarker of oxidative stress, suggests the role of oxidative stress in etiopathogenesis of endometrial polyps.IMPACT STATEMENTWhat is already known on this subject? Studies demonstrate that oestrogen and progesterone play an important role in pathogenesis of endometrial polyps. Inorganic heavy metal ions that bind and activate oestrogen receptors are referred to as 'metalloestrogens'. Apart from toxic effects, metalloestrogens have been linked to the aetiology of oestrogen-dependent diseases such as breast and endometrium cancer and endometriosis. However, serum levels of heavy metals were not investigated in a large group of endometrial polyp patients.What do the results of this study add? This is the first study investigating the serum levels of heavy metals in a large group of endometrial polyp patients. We did not observe any increased serum levels of heavy metals in endometrial polyp patients. Our results might suggest that oestrogenic heavy metal exposure has no role in the appearance of endometrial polyps. However, increased Cu/Zn ratio due to low serum levels zinc suggests oxidative stress might play a role in endometrial polyps.What are the implications of these findings for clinical practice and/or further research? Further research of heavy metals in endometrial polyps with simultaneous blood and tissue samples could show the precise effect of environmental exposure of metalloestrogens in aetiopathogenesis of endometrial polyps.

Enhancing the activity and stability of Mn-superoxide dismutase by one-by-one ligation to catalase

Dismutation of superoxide by superoxide dismutase (SOD) generates hydrogen peroxide, which may be reduced to hydroxyl radical. The generated H₂O₂ during the catalysis can have an oxidative damage to SOD. Hydrogen peroxide decomposition by catalase (CAT) can help circumvent the problem. Mn-superoxide dismutase (herein referred to as SOD) and CAT are dimeric and tetrameric proteins, respectively. Herein, through intein-mediated in vivo subunit splicing, the C-terminus of the CAT subunit (CAT^S) has been specifically ligated to the N-terminus of the SOD subunit (SOD^S) with a peptide bond. Thus, the splicing product SOD&CAT combines the superoxide anion (•O₂^-) scavenging ability and the ability of decomposing H₂O₂. The in vivo subunit splicing has little effect on the secondary structures of the enzymes as confirmed by circular dichroism (CD) spectra. Fluorescence spectra showed that the splicing product SOD&CAT has a higher stability than SOD. In the splicing product SOD&CAT, the SOD subunits are in close proximity to the CAT subunits, facilitating immediate transfer of H₂O₂ between the enzymes and enabling efficient decomposition of H₂O₂. SOD&CAT exhibited a superoxide anion (•O₂^-) scavenging ability 244% higher than that of SOD and 46% higher than that of the mixed enzymes SOD+CAT.

A contribution to the elemental profile of the leaf samples of newly developed Cabernet Franc varieties

The elemental profile of the leaf samples of three Cabernet Franc clone candidates recently developed in Serbia (Nos. 02, 010 and 012) obtained in the last phase of clonal selection was examined within this study by ICP-OES. Optimal content of Al, Fe, Cu and Zn, the metals well known for their links with a number of neurodegenerative disorders including Alzheimer's disease, has actually highlighted the potential of the leaf sample No. 10 to afford a novel food supplement of natural origin possessing well balanced metal ingredients. Furthermore, lower content of some other elements (Cr, Mn, Ni and Pb) thoroughly supports such a claiming. Finally, the most favourable K/Na ratio observed for the aforementioned sample points out its likely cardioprotectivity. However, two other Cabernet Franc clone candidates might also be recommended for breeding in the same or similar viticultural conditions, since all obtained values were below toxic ones for human consumption.