Effect of rare earth elements on growth and antioxidant metabo- lism in Lemna minor L.

Lemna minor is frequently used in bioremediation processes to remove nutrients and contaminants from waste water. In this work the response of L. minor to treatments with lanthanum nitrate and with a mix of several light rare earth elements (REE) nitrates was investigated. Preliminary results indicate that L. minor shows an overall good tolerance to the presence of REE in the media. Toxic effects were observed after prolonged exposition to high concentration of REE. An increase in ascorbate and glutathione content as well as in ascorbate peroxidase, dehy- droascorbate reductase and ascorbate free radical (AFR) reductase activity was observed in treated plants

Effect of cerium on growth and antioxidant metabolism of Lemna minor L

An increasing input rate of rare earth elements in the environment is expected because of the intense extraction of such elements form their ores to face human technological needs. In this study Lemna minor L. plants were grown under laboratory conditions and treated with increasing concentrations of cerium (Ce) ions to investigate the effects on plant growth and antioxidant systems. The growth increased in plants treated with lower Ce concentrations and reduced in plants treated with higher concentrations, compared to control plants. In plants treated with higher Ce concentrations lower levels of chlorophyll and carotenoid and the appearance of chlorotic symptoms were also detected. Increased levels of hydrogen peroxide, antioxidant metabolites and antioxidant activity confirmed that higher Ce concentrations are toxic to L. minor. Ce concentration in plant tissues was also determined and detectable levels were found only in plants grown on Ce-supplemented media. The use of duckweed plants as a tool for biomonitoring of Ce in freshwater is discussed

Rare earth elements in human and animal health: State of art and research priorities

"Background: A number of applications have been developed using rare earth elements (REE), implying several human exposures and raising unsolved questions as to REE-associated health effects. Methods: A MedLine survey was retrieved from early reports (1980s) up to June 2015, focused on human and animal exposures to REE. Literature from animal models was selected focusing on REE-associated health effects. Results: Some REE occupational exposures, in jobs such as glass polishers, photoengravers and movie projectionists showed a few case reports on health effects affecting the respiratory system. No case-control or cohort studies of occupational REE exposures were retrieved. Environmental exposures have been biomonitored in populations residing in REE mining areas, showing REE accumulation. The case for a iatrogenic REE exposure was raised by the use of gadolinium-based contrast agents for nuclear magnetic resonance. Animal toxicity studies have shown REE toxicity, affecting a number of endpoints in liver, lungs and blood. On the other hand, the use of REE as feed additives in livestock is referred as a safe and promising device in zootechnical activities, possibly suggesting a hormetic effect both known for REE and for other xenobiotics. Thus, investigations on long-term exposures and observations are warranted. Conclusion: The state of art provides a limited definition of the health effects in occupationally or environmentally REE-exposed human populations. Research priorities should be addressed to case-control or cohort studies of REE-exposed humans and to life-long animal experiments. (C) 2015 Elsevier Inc. All rights reserved.

Effects of the fertilizer added with dmpp on soil nitrous oxide emissions and microbial functional diversity

Agricultural sites contribute extensively to atmospheric emissions of climate-altering gases such as nitrous oxide. Several strategies have been considered to mitigate the impact of agriculture on climate, among these the utilization of fertilizers added with nitrification inhibitors such as DMPP (3,4-dimethylpyrazole phosphate) may represent a suitable solution. DMPP inhibits the growth and activity of ammonia-oxidizing microorganisms, particularly the ammonia-oxidizing bacteria, which are involved in N2O production. At present, little information is available on the effects of DMPP on the catabolic diversity of soil microbial community. In this study, the N2O emission by soil was performed by using the static chamber technique. The biological determinations of the microbial biomass carbon and the catabolic profile were assessed by measuring the substrate-induced respiration during the entire growing season of a potato crop under two nitrogen treatments: fertilization with and without DMPP. Our results did not show a clear mitigation of N2O emission by DMPP, even if a tendency to lower N2O fluxes in DMPP plots occurred when soil temperatures were lower than 20◦C. Conversely, DMPP deeply affected the microbial biomass and the catabolism of soil microorganisms, exerting a negative effect when it accumulated in excessive doses in the soil, limiting the growth and the capacity of soil microorganism communities to use different substrates

Physiological responses of 'Italia' grapevines infected with Esca pathogens

Physiological features were examined of a 20-year-old Vitis vinifera 'Italia' table grape vineyard cropped in Apulia, Italy. Healthy vines with no foliar symptoms and any indications of wood or berry alterations, vines with natural wood infections by Phaeoacremonium minimum (syn. P. aleophilum) and Phaeomoniella chlamydospora showing brown wood streaking symptoms, and vines naturally infected with P. minimum, P. chlamydospora and Fomitiporia mediterranea with brown wood streaking and white rot symptoms, were surveyed. Bleeding xylem sap, collected at bud-break from healthy vines showed the greatest total ascorbic acid level, while vines with brown wood streaking and white rot had the greatest viscosity coefficient, glutathione concentration, and plant growth regulator activities. Compared to healthy vines, leaves of wood affected vines, sampled during the unfolded leaf, fruit setting, cluster closing and bunch ripening vine growth stages, had reduced fresh and dry weights, total chlorophyll concentrations, and increased leaf surface area. Low ascorbic acid and reduced glutathione concentrations, weak redox state, and moderate levels of dehydroascorbic acid and oxidized glutathione were also detected in these vines. Analyses also detected reduced activities of dehydroascorbate reductase, ascorbate free radical reductase and glutathione reductase in diseased vines. The cell membrane damage, associated with lipid peroxidation, was coupled with high hydrogen peroxide concentrations. These changes could contribute to the cell death of leaves and foliar symptom development. The ascorbate-glutathione cycle supports grapevine susceptibility to Esca complex-associated fungi

Natural iminosugar (+)-lentiginosine inhibits ATPase and chaperone activity of Hsp90

Heat shock protein 90 (Hsp90) is a significant target in the development of rational cancer therapy due to its role at the crossroads of multiple signaling pathways associated with cell proliferation and cell viability. The relevance of Hsp90 as a therapeutic target for numerous diseases states has prompted the identification and optimization of novel Hsp90 inhibitors as an emerging therapeutic strategy. We performed a screening aimed to identify novel Hsp90 inhibitors among several natural compounds and we focused on the iminosugar (+)-lentiginosine, a natural amyloglucosidases inhibitor, for its peculiar bioactivity profile. Characterization of Hsp90 inhibition was performed using a panel of chemical and biological approaches, including limited proteolysis, biochemical and cellular assays. Our result suggested that the middle domain of Hsp90, as opposed to its ATP-binding pocket, is a promising binding site for new classes of Hsp90 inhibitors with multitarget anti-cancer potentia

Resolving the effects of environmental micro- and nanoplastics exposure in biota: A knowledge gap analysis

The pervasive spread of microplastics (MPs) and nanoplastics (NPs) has raised significant concerns on their toxicity in both aquatic and terrestrial environments. These polymer-based materials have implications for plants, wildlife and human health, threatening food chain integrity and ultimate ecosystem resilience. An extensive – and growing – body of literature is available on MP- and NP-associated effects, including in a number of aquatic biota, with as yet limited reports in terrestrial environments. Effects range from no detectable, or very low level, biological effects to more severe outcomes such as (but not limited to) increased mortality rates, altered immune and inflammatory responses, oxidative stress, genetic damage and dysmetabolic changes. A well-established exposure route to MPs and NPs involves ingestion with subsequent incorporation into tissues. MP and NP exposures have also been found to lead to genetic damage, including effects related to mitotic anomalies, or to transmissible damage from sperm cells to their offspring, especially in echinoderms. Effects on the proteome, transcriptome and metabolome warrant ad hoc investigations as these integrated “omics” workflows could provide greater insight into molecular pathways of effect. Given their different physical structures, chemical identity and presumably different modes of action, exposure to different types of MPs and NPs may result in different biological effects in biota, thus comparative investigations of different MPs and NPs are required to ascertain the respective effects. Furthermore, research on MP and NP should also consider their ability to act as vectors for other toxicants, and possible outcomes of exposure may even include effects at the community level, thus requiring investigations in mesocosm models

Natural iminosugar (+)-lentiginosine inhibits ATPase and chaperone activity of Hsp90

Heat shock protein 90 (Hsp90) is a significant target in the development of rational cancer therapy due to its role at the crossroads of multiple signaling pathways associated with cell proliferation and cell viability. The relevance of Hsp90 as a therapeutic target for numerous diseases states has prompted the identification and optimization of novel Hsp90 inhibitors as an emerging therapeutic strategy. We performed a screening aimed to identify novel Hsp90 inhibitors among several natural compounds and we focused on the iminosugar (+)-lentiginosine, a natural amyloglucosidases inhibitor, for its peculiar bioactivity profile. Characterization of Hsp90 inhibition was performed using a panel of chemical and biological approaches, including limited proteolysis, biochemical and cellular assays. Our result suggested that the middle domain of Hsp90, as opposed to its ATP-binding pocket, is a promising binding site for new classes of Hsp90 inhibitors with multi-target anti-cancer potential

Increase of poly(ADP-ribose) polymerase mRNA levels during TPA-induced differentiation of human lymphocytes

AbstractThe non-mitogenic stimulation of human peripheral blood mononuclear cells (PBMC) with low concentrations of the phorbol ester 12-O-tetradecanoylphorbol 13-acatate (TPA) caused a progressive increase in the percent fraction of the cells that were positive for the early activating antigen CD69. At the same time, it caused a progressive increase in the steady-state levels of poly(ADP-ribose) polymerase (pADPRP) transcripts. A further increase in TPA concentration, while inducing the maximal expression of the levels of CD69 activating surface antigen, both in the presence or in the absence of proliferative activity, did not evoke any additional hightening of pADPRP mRNA levels. Time course of PBMC stimulation with a non-mitogenic dose or TPA showed an early increase in the accumulation of pADPRP mRNA, which changed at 8-16 h. and remained high for several days thereafter. On the basis of these data, we suggest flat the increase in pADPRP mRNA may be associated with the commitment of human lymphocytes from a quiescent (G0) to an activated (G1) state