Remediation of Cadmium Stress in Strawberry Plants Using Humic Acid and Silicon Applications.

(1) Background: Strawberry plants are strongly affected by heavy-metal-contaminated soils, which affects plant growth, yield and fruit quality. The aim of this work was to study the effects of a combination and individual application of silicon (Si) and humic acid (HA) on growth and development of Rubygem strawberries exposed to cadmium (Cd) in greenhouse conditions. (2) Methods: Morphological, physiological and biochemical parameters, including minerals in roots and leaves were determined. (3) Results: Cd stress in strawberry plants decreased plant fresh and dry weight; leaf stomatal conductance; leaf relative water content and chlorophyll content; number of leaves; leaf area; leaf N, P and K levels; and root P, N, Mg, K and Ca contents. Cd increased membrane permeability, leaf temperature, proline levels and lipid peroxidation. Si and HA individual applications to strawberries mitigated the negative effect of Cd stress on biochemical, physiological, morphological and minerals parameters by decreasing membrane permeability, leaf temperature, proline levels and lipid peroxidation. (4) Conclusions: Our findings highlighted that applications of Si, HA and Si + HA were effective in conferring Cd tolerance in strawberry plants by upregulating their many morphological, physiological and biochemical properties and reducing Cd stress.

The relationship between plasma aluminum content, lymphocyte DNA damage, and oxidative status in persons using aluminum containers and utensils daily.

OBJECTIVES: The aim of this study was to explore the in vivo effect of the plasma aluminum content on lymphocyte DNA damage, the plasma protein carbonyl (PC) content, and malondialdehyde (MDA) and total antioxidative capacity (TAC) levels in aluminum exposed and non-exposed humans. DESIGN AND METHODS: Peripheral blood samples were collected from in vivo aluminum exposed and non-exposed humans and the above parameters were measured. RESULTS: The mean values of lymphocyte DNA damage, plasma MDA, PC levels, and aluminum concentrations were found to be significantly higher in the aluminum exposed group than within the control group (p<0.01). On the other hand, plasma TAC levels were found to be significantly lower in the aluminum exposed group than in the control group (p<0.001). Significant positive correlations were found to exist between lymphocyte DNA damage and the aluminum concentration (r=0.643, p<0.001), DNA damage and MDA (r=0.491, p<0.001), and DNA damage and PC (r=0.548, p<0.01). A negative correlation was found between TAC and DNA damage (r=-0.600 p<0.001) in the aluminum exposed group. CONCLUSION: Findings from the study revealed that an increased plasma aluminum concentration was associated with increased oxidative stress and increased DNA damage in aluminum exposed humans.

Mononuclear leukocyte DNA damage and oxidative stress: the association with smoking of hand-rolled and filter-cigarettes.

Cigarette smoking is a major cause of human cancer at various sites, although its carcinogenic mechanisms still remain unestablished. Based on the use of a filter, cigarette smoke can be divided into a gas phase and a tar phase. Both contain different concentrations of oxidants, free radicals and tobacco-specific carcinogens. To explore the effects of both filtered and non-filtered cigarette smoke on DNA damage and oxidative status, we measured the level of mononuclear leukocyte DNA damage by use of the single-cell gel electrophoresis (Comet) assay. We also determined malondialdehyde (MDA), protein carbonyl content (PC) and total antioxidative capacity (TAC) levels in blood plasma of smokers of manufactured filter-cigarettes and of hand-rolled cigarettes. Cotinine levels were also measured in plasma to estimate the degree of smoking. Mononuclear leukocyte DNA damage, plasma MDA, plasma PC and plasma cotinine levels were found significantly higher, while plasma TAC levels were found significantly lower in smokers of filter-cigarettes and smokers of hand-rolled cigarettes, compared with control subjects. TAC levels in hand-rolled and manufactured filter-cigarette smokers were not significantly different from each other. However, the levels of DNA damage, plasma MDA, plasma cotinine, and plasma protein oxidation were significantly higher in hand-rolled cigarette smokers than in filter-cigarette smokers. There was a significant positive correlation between MDA and DNA damage in both hand-rolled cigarette smokers and manufactured filter-cigarette smokers. This study indicates that smoking of hand-rolled cigarettes has stronger genotoxic and oxidative effects on the metabolism than smoking of manufactured filter-cigarettes. We propose that these harmful effects could be attributed to the higher level of oxidants.