Synergistic health effects between chemical pollutants and electromagnetic fields

Times Cited: 0Humans and ecosystems are exposed to highly variable and unknown cocktail of chemicals and radiations. Although individual chemicals are typically present at low concentrations, they can interact with each other resulting in additive or potentially synergistic mixture effects. This was also observed with products obtained by radiation actions such as sunlight or electromagnetic fields that can change the effects of chemicals, such as pesticides, and metal trace elements on health. Concomitant presence of various pesticides and their transformation products adds further complexity to chemical risk assessment since chronic inflammation is a key step for cancer promotion. Degradation of a parent molecule can produce several by-products which can trigger various toxic effects with different impacts on health and environment. For instance, the cocktail of sunlight irradiated sulcotrione pesticide has a greater cytotoxicity and genotoxicity than parent molecule, sulcotrione, and questions about the impact of photochemical process on environment. Adjuvants were shown to modify the biological features of pesticides. Addition of other elements, metals or biological products, can differently enhance cell toxicity of pesticides or electromagnetic radiations suggesting a synergy in living organisms. Electromagnetic fields spreading, pesticide by-products and mixtures monitoring become greater for environmental contamination evaluations

Redox biology response in germinating Phaseolus vulgaris seeds exposed to copper: Evidence for differential redox buffering in seedlings and cotyledon.

In agriculture, heavy metal contamination of soil interferes with processes associated with plant growth, development and productivity. Here, we describe oxidative and redox changes, and deleterious injury within cotyledons and seedlings caused by exposure of germinating (Phaseolus vulgaris L. var. soisson nain hâtif) seeds to copper (Cu). Cu induced a marked delay in seedling growth, and was associated with biochemical disturbances in terms of intracellular oxidative status, redox regulation and energy metabolism. In response to these alterations, modulation of activities of antioxidant proteins (thioredoxin and glutathione reductase, peroxiredoxin) occurred, thus preventing oxidative damage. In addition, oxidative modification of proteins was detected in both cotyledons and seedlings by one- and two-dimensional electrophoresis. These modified proteins may play roles in redox buffering. The changes in activities of redox proteins underline their fundamental roles in controlling redox homeostasis. However, observed differential redox responses in cotyledon and seedling tissues showed a major capacity of the seedlings' redox systems to protect the reduced status of protein thiols, thus suggesting quantitatively greater antioxidant protection of proteins in seedlings compared to cotyledon. To our knowledge, this is the first comprehensive redox biology investigation of the effect of Cu on seed germination

Representative images of 1DE gels of proteins (100 μg) in cotyledons of bean seeds germinated for 3 days in the presence of (A) distilled water (CTR) or (B) 200 μM Cu.

<p>Gels were stained with Coomassie G-250 (scanned with GS-800 calibrated densitometer) and with FTSC labeling (scanned with Typhoon 9400 scanner). Total optical densities for each lane obtained from FTSC staining were normalized with those from Coomassie G-250 staining of the same gel. (C, D) Levels of proteins containing carbonyl groups. Values shown are (C) means of 4 biological replicates (±SD) numbered from 1 to 4, and (D) means of 4 technical replicates (±SD). Each measurement was performed in an extract obtained from several cotyledons. Analyses were performed using ANOVA, student’s T test; ***p<0.001.</p

Time courses of (A, B) germination rate and (C, D, E, F) seedling length in bean seeds in the absence (CTR) and in the presence of CuCl₂ (concentrations 20, 50, 100, 200, 500 μM).

<p>Letters indicate significant differences compared with the respective control sample (a: p < 0.05, b: p < 0.01 and c: p < 0.001).</p

Activities of redox enzymes in the seedlings (3 days-old) and the cotyledons (9 days-old) of germinated bean seeds in the presence of H₂O (CTR) or 200 μM Cu.

<p>Activities of redox enzymes in the seedlings (3 days-old) and the cotyledons (9 days-old) of germinated bean seeds in the presence of H₂O (CTR) or 200 μM Cu.</p

Representative images of 1DE gels of proteins (100 μg) in seedlings of bean seeds germinated for 3 days. (A) In the presence of distilled water (CTR) or (B) 200 μM Cu. Gels were stained with Coomassie G-250 (scanned with GS-800 calibrated densitometer) and with IAF labeling (scanned with Typhoon 9400 scanner).

<p>Total optical densities for each lane obtained from IAF staining were normalized with those from Coomassie G-250 staining of the same gel. (C, D) Levels of proteins containing thiol groups. Values shown are (C) means of 4 biological replicates (±SD) numbered from 1 to 4, and (D) means of 4 technical replicates (±SD). Each measurement was performed in an extract obtained from several seedlings. Analyses were performed using ANOVA, student’s T test; *p<0.05, **p<0.01, ***p<0.001.</p

Enzymatic activities of SOD, CAT and peroxidases (APX, GPX and POX) in (A, C) seedlings and (B, D) cotyledons of bean seeds during germination in the presence of distilled water (CTR) or 200 μM Cu.

<p>Values are means ± SE (n = 5). Letters indicate significant differences compared with the respective control sample (a: p < 0.05, b: p < 0.01 and c: p < 0.001).</p

Levels of protein carbonyl and thiol groups in the seedlings (3 days-old) and the cotyledons (9 days-old) of germinated bean seeds in the presence of H₂O (CTR) or 200 μM Cu.

<p>Levels of protein carbonyl and thiol groups in the seedlings (3 days-old) and the cotyledons (9 days-old) of germinated bean seeds in the presence of H₂O (CTR) or 200 μM Cu.</p

Profiles of the expression of proteins containing carbonyl groups in (A, B) seedlings and (C, D) cotyledons of bean seeds germinated for 9 days in the presence of distilled water (CTR) or 200 μM Cu.

<p>Proteins (1200 μg) were labeled with FTSC and separated by 2-D SDS-PAGE. Figures show spots of interest in representative gels from (A) colloidal Coomassie Brilliant G-250 staining (scanned with GS-800 calibrated densitometer) and (B) FTSC labeling (scanned with Typhoon 9400 scanner; 600 PMT). Numbers correspond to spots of p<0.05 and Fold induction >1.5 (spots identified).</p

Proteins containing thiol groups (IAF labeling) in the seedlings (3 days-old) (a) and the cotyledons (9 days-old) (b) of germinated bean seeds in the presence of H₂O (CTR) or 200 μM Cu.

<p>Proteins containing thiol groups (IAF labeling) in the seedlings (3 days-old) (a) and the cotyledons (9 days-old) (b) of germinated bean seeds in the presence of H₂O (CTR) or 200 μM Cu.</p