Magnesium, C-reactive protein, and cortisol in drug-naïve patients with short illness-duration, first episode major depressive disorder: possible immunomodulatory role for magnesium.

Plasma magnesium concentration alterations, hypercortisolaemia, and systemic inflammation are observed in major depressive disorder (MDD). This exploratory study examined whether, and to what extent, plasma magnesium is related to C-reactive protein (CRP) levels and cortisolaemia in MDD. The concentrations of plasma magnesium, salivary CRP, and baseline plasma cortisol were studied in 20, treatment-naïve MDD patients with short-illness-duration, first affective episodes and 20 matched controls. Depressed patients showed a basal score higher than 20 on the Hamilton Rating Scale for Depression (HAMD-17). Significantly higher magnesium (p = 0.016) and baseline cortisol (p = 0.01) concentrations were observed in MDD as compared to controls. No significant difference in CRP concentrations between the MDD and control groups was observed. A significant negative correlation was seen between magnesium and CRP in MDD (p<0.01), whereas no correlation was found in controls. A significant positive correlation was found between cortisol and CRP, both in MDD subjects (p = 0.008) and controls (p = 0.004). No significant correlations were observed between magnesium and cortisol levels. The study supports data for hypercortisolaemia in MDD, but provides no evidence of primary hypomagnesaemia or elevated CRP levels in drug-naïve MDD patients with short-illness-duration. The study supports the hypothesis linking hypercortisolaemia to systemic inflammation, with hypermagnesaemia exerting an immunomodulatory action at early stages of the disease.

Time-dependent changes in antioxidative enzyme expression and photosynthetic activity of Chlamydomonas reinhardtii cells under acute exposure to cadmium and anthracene.

Heavy metals (HM) and polycyclic aromatic hydrocarbons (PAHs) are present in the freshwater environment at concentrations that can be hazardous to the biota. Among HMs and PAHs, cadmium (Cd) and anthracene (ANT) are the most prevalent and toxic ones. The response of Chlamydomonas cells to Cd and ANT at concentrations that markedly reduced the growth of algal population was investigated in this study. At such concentrations, both cadmium and anthracene were recognized as oxidative stress inducers, since high concentration of H2O2 in treated cultures was observed. Therefore, as a part of the "molecular phase" of the cell response to this stress, we examined the time-dependent expression of genes encoding the main antioxidative enzymes: superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX), as well as the activity of these enzymes in cells, with special attention paid to chloroplastic and mitochondrial isoforms of SOD. To characterize the cell response at the "physiological level", we examined the photosynthetic activity of stressed cells via analysis of chlorophyll a fluorescence in vivo. In contrast to standard ecotoxicity studies in which the growth end-points are usually determined, herein we present time-dependent changes in algal cell response to Cd- and ANT-induced stress. The most significant effect(s) of the toxicants on photosynthetic activity was observed in the 6th hour, when strong depression of PI parameter value, an over 50 percent reduction of the active reaction center fraction (RC0) and a 3-fold increase in non-photochemical energy dissipation (DI0/RC) were noted. At the same time, the increase (up to 2.5-fold) in mRNA transcript of SOD and CAT genes, followed by the enhancement in the enzyme activity was observed. The high expression of the Msd 3 gene in treated Chlamydomonas cells probably complements the partial loss of chloroplast Fe-SOD and APX activity, while catalase and Mn-SOD 5 seem to be the major enzymes responsible for mitochondrion protection. The progressive increase in SOD and CAT activities seems to be involved in the recovery of photosynthesis within 12-24h after the application of the toxicants.

Adaptation strategies of two closely related Desmodesmus armatus (green alga) strains contained different amounts of cadmium: a study with light-induced synchronized cultures of algae.

During the Desmodesmus armatus cell cycle, 8-celled coenobia of 276-4d strain accumulated a much lower amounts of cadmium than unicells of B1-76 strain. Cadmium reduced growth and photosynthesis in the cells of strain B1-76, but not those of 276-4d strain. Cells of 276-4d strain revealed a higher activity of superoxide dismutase (SOD) isoforms, in particular the activity and protein content of Fe-SOD. Cu/Zn-SOD was earlier and much stronger induced by cadmium in 276-4d than in B1-76 strain, whereas Fe- and Mn-SOD activity and Fe-SOD synthesis were induced only in 276-4d strain. Cadmium did not affect the heat shock protein 70 synthesis in B1-76 strain, but significantly stimulated this process in 276-4d strain. The level of glutathione increased 30-fold during cell development of Cd-exposed 276-4d strain, while in B1-76 it increased about 12 timed. Matured cells of both strains exposed to cadmium produced comparable amounts of phytochelatins and other thiol peptides, but their production in young cells of B1-76 strain was much higher than in 276-4d strain. In conclusion, a complex of internal detoxification mechanisms appeared to be more efficient in cells of 276-4d strain than B1-76 one.