Antidepressant-like activity of magnesium in the olfactory bulbectomy model is associated with the AMPA/BDNF pathway

Rationale. Numerous studies suggest agents that act on glutamatergic transmission as potential antidepressants. Preclinical and clinical evidence suggests that magnesium, an N-methyl-d-aspartate receptor blocker, may be useful in the treatment of depression. Objective. The aim of this study was to investigate the effects of magnesium on behavior; protein levels of GluN2A, GluN2B [N-methyl-d-aspartate receptor (NMDAR) subunits], GluA1 [α-amino-3-hydroxy-5 methyl-4-isoxazolepropionic acid (AMPA) subunit], phospho-Ser-831-GluA1 (P-S831), phospho-Ser-845-GluA1 (P-S845), and brain-derived neurotrophic factor (BDNF); and messenger RNA (mRNA) levels of GluN2A and GluN2B in different brain areas in the olfactory bulbectomy (OB) model of depression in rats. Methods. Magnesium was administered once daily for 14 days at three doses (10, 15, and 20 mg/kg, intraperitoneal) to sham and OB rats. Following treatment, open field and passive avoidance tests were performed in the sham and OB rats. After 24 h, the hippocampus, the prefrontal cortex (PFC), and the amygdala of rats treated with the most active dose (15 mg/kg) were harvested, and the protein and mRNA levels were determined. Results. Chronic administration of magnesium (15 and 20 mg/kg) reduced the number of trials required to learn passive avoidance and reduced the OB-induced hyperactivity. OB increased the P-S845 level in the hippocampus, which was reduced by magnesium treatment. Magnesium significantly increased the levels of BDNF, GluN2B, P-S831, and P-S845 protein (and mRNA) primarily in the PFC and the hippocampus in OB rats. Conclusion. For the first time, the present results demonstrate the antidepressant-like activity of magnesium in the OB animal model of depression and indicate the potential involvement of the AMPA/BDNF pathway in this activity

Study of the serum copper levels in patients with major depressive disorder

Copper may be involved in the pathophysiology of depression. Clinical data on this issue are very limited and not conclusive. The purpose of the study was to determine the copper concentration in the serum of patients with major depressive disorder and to discuss its potential clinical usefulness as a biomarker of the disease. A case–control clinical study included 69 patients with current depressive episode, 45 patients in remission and 50 healthy volunteers. Cu concentration was measured by electrothermal atomic absorption spectrometry (ETAAS). The mean serum copper level in depressed patients was slightly lower (by 11 %; not statistically significant) than in the control group. Furthermore, there was no significant difference in Cu(2+) concentration between depressive episode and remission, nor between remission and control group. In the remission group were observed significant correlations between copper levels and the average number of relapses over the past years or time of remission. There was no correlation between serum copper and severity of depression, as measured by HDRS and MADRS. The obtained results showed no significant differences between the copper concentration in the blood serum of patients (both with current depressive episode and in remission) and healthy volunteers, as well as the lack of correlations between the copper level in the active stage of the disease and clinical features of the population. Our study is the first conducted on such a large population of patients, so the results may be particularly important and reliable source of knowledge about the potential role of copper in depression

Edible cyanobacterial genus <i>Arthrospira</i>: actual state of the art in cultivation methods, genetics, and application in medicine

The cyanobacterial genus Arthrospira appears very conserved and has been divided into five main genetic clusters on the basis of molecular taxonomy markers. Genetic studies of seven Arthrospira strains, including genome sequencing, have enabled a better understanding of those photosynthetic prokaryotes. Even though genetic manipulations have not yet been performed with success, many genomic and proteomic features such as stress adaptation, nitrogen fixation, or biofuel production have been characterized. Many of above-mentioned studies aimed to optimize the cultivation conditions. Factors like the light intensity and quality, the nitrogen source, or different modes of growth (auto-, hetero-, or mixotrophic) have been studied in detail. The scaling-up of the biomass production using photobioreactors, either closed or open, was also investigated to increase the production of useful compounds. The richness of nutrients contained in the genus Arthrospira can be used for promising applications in the biomedical domain. Ingredients such as the calcium spirulan, immulina, C-phycocyanin, and γ-linolenic acid (GLA) show a strong biological activity. Recently, its use in the fight against cancer cells was documented in many publications. The health-promoting action of “Spirulina” has been demonstrated in the case of cardiovascular diseases and age-related conditions. Some compounds also have potent immunomodulatory properties, promoting the growth of beneficial gut microflora, acting as antimicrobial and antiviral. Products derived from Arthrospira were shown to successfully replace biomaterial scaffolds in regenerative medicine. Supplementation with the cyanobacterium also improves the health of livestock and quality of the products of animal origin. They were also used in cosmetic preparations

Pectobacterium parvum sp. nov., having a Salmonella SPI-1-like Type III secretion system and low virulence

Corrigendum: Pectobacterium parvum sp. nov., having a Salmonella SPI-1-like Type III secretion system and low virulence. Pages: 2959-2959. https://doi.org/10.1099/ijsem.0.004111Pectobacterium strains isolated from potato stems in Finland, Poland and the Netherlands were subjected to polyphasic analyses to characterize their genomic and phenotypic features. Phylogenetic analysis based on 382 core proteins showed that the isolates clustered closest to Pectobacterium polaris but could be divided into two clades. Average nucleotide identity (ANI) analysis revealed that the isolates in one of the clades included the P. polaris type strain, whereas the second Glade was at the border of the species P. polaris with a 96 % ANI value. In silico genome-to-genome comparisons between the isolates revealed values below 70%, patristic distances based on 1294 core proteins were at the level observed between closely related Pectobacterium species, and the two groups of bacteria differed in genome size, G+C content and results of amplified fragment length polymorphism and Biolog analyses. Comparisons between the genomes revealed that the isolates of the atypical group contained SPI-1-type Type III secretion island and genes coding for proteins known for toxic effects on nematodes or insects, and lacked many genes coding for previously characterized virulence determinants affecting rotting of plant tissue by soft rot bacteria. Furthermore, the atypical isolates could be differentiated from P. polaris by their low virulence, production of antibacterial metabolites and a citrate-negative phenotype. Based on the results of a polyphasic approach including genome-to-genome comparisons, biochemical and virulence assays, presented in this report, we propose delineation of the atypical isolates as a novel species Pectobacterium parvum, for which the isolate s0421(T) (CFBP 8630(T)=LMG 30828(T)) is suggested as a type strain.Peer reviewe

Functional and Molecular Changes in the Prefrontal Cortex of the Chronic Mild Stress Rat Model of Depression and Modulation by Acute Ketamine

Stress is a primary risk factor in the onset of neuropsychiatric disorders, including major depressive disorder (MDD). We have previously used the chronic mild stress (CMS) model of depression in male rats to show that CMS induces morphological, functional, and molecular changes in the hippocampus of vulnerable animals, the majority of which were recovered using acute subanesthetic ketamine in just 24 h. Here, we focused our attention on the medial prefrontal cortex (mPFC), a brain area regulating emotional and cognitive functions, and asked whether vulnerability/resilience to CMS and ketamine antidepressant effects were associated with molecular and functional changes in the mPFC of rats. We found that most alterations induced by CMS in the mPFC were selectively observed in stress-vulnerable animals and were rescued by acute subanesthetic ketamine, while others were found only in resilient animals or were induced by ketamine treatment. Importantly, only a few of these modifications were also previously demonstrated in the hippocampus, while most are specific to mPFC. Overall, our results suggest that acute antidepressant ketamine rescues brain-area-specific glutamatergic changes induced by chronic stress

The serum magnesium concentration as a potential state marker in patients with unipolar affective disorder

Aim. The growing body of evidence suggests that magnesium levels can serve as a marker of major depressive disorder (MDD), but findings from clinical trials remain inconclusive. The aim of the presented study was to determine the magnesium concentration in serum of patients with MDD (in the active stage of the disease or in remission) and to analyze the role of magnesium levels as a potential marker of the disease. Methods. Sixty-nine patients with current depressive episode, 45 patients in remission and 50 healthy volunteers were enrolled into the case-control study. The magnesium concentration was measured by flame atomic absorption spectrometry (FAAS). Results. The mean serum magnesium concentration of patients in the depressed phase was significantly higher, compared to the control group. Moreover, magnesium levels of patients in the remission were not significantly different from the concentrations recorded in the healthy volunteers. There was also a positive correlation between the magnesium levels and the severity of depression measured by the Hamilton Rating Scale for Depression (HDRS) and the Montgomery-Asberg Depression Rating Scale (MADRS). Conclusions. The obtained results may suggest a role of magnesium as a state marker reflecting the pathophysiological changes underlying MDD and accompanying severe depressive episodes

The serum concentration of magnesium as a potential state marker in patients with diagnosis of bipolar disorder

Aim. Few scientific reports indicate changes in the concentration of magnesium in the blood of patients with bipolar disorder (BD). So far very little studies concerning these issues have been conducted. Therefore, the aim of this study was to evaluate the serum magnesium level in patients with bipolar disorder (in different phases of the disease) in comparison to healthy volunteers. Methodology. The study included 129 patients (58 subjects in depressive episode, 23 in manic episode and 48 patients in remission) with the diagnosis of bipolar disorder type I or II. The control group consisted of 50 healthy people. Magnesium concentration was measured using flame atomic absorption spectrometry (FAAS). Results. Patients with a current depressive or manic/hypomanic episode had statistically significantly elevated serum magnesium levels compared to healthy volunteers. Moreover, a positive correlation between the duration of the manic/hypomanic episode and the relapse frequency in the last year was observed. The concentration of magnesium in patients in remission was unchanged in relation to the control group. Conclusions. Presented findings suggest a role of serum magnesium level as a potential state marker, reflecting the pathophysiological changes associated with acute episodes of bipolar disorder