Panax quinquefolius: An overview of the contaminants

The root of Panax quinquefolius has been used as a food supplement and botanical drug throughout the world for many years. During growth, harvest, processing, and storage, it can be polluted by molds, pesticides, heavy metals, and other chemicals, resulting in contamination with mycotoxins, pesticide residues, and heavy metals, as well as other substances. These contaminants may be harmful to human health. In this review, we summarize the contaminants and significant advances that have been made in the study of these contaminants, focusing on the analytical methods and contamination management techniques for P. quinquefolius that have been developed over the last several decades.     

Effects of fusariotoxin co-exposure on THP-1 human immune cells

Deoxynivalenol (DON), nivalenol (NIV), T-2 toxin (T2), fumonisin B1 (FB1), zearalenone (ZEA), and moniliformin (MON) mycotoxins are common food and feed contaminants produced by Fusarium spp. However, while they are usually found to co-occur in a large range of commodities, only few data are available on mycotoxin co-exposure effects and cellular response mechanisms. In this study, the individual and combined toxic effects of these fusariotoxins were evaluated on the THP-1 human immune cell line as major fusariotoxins are mostly potent immunomodulators. In particular, four relevant fusariotoxin mixtures, namely DON-MON, DON-FB1, DON-ZEA, and NIV-T2, were studied using several parameters including cell viability as well as the expression of cell surface markers and the main mitogen-activated protein kinases (MAPKs). After 48 h exposure, a reduction of cell viability in a dose-dependent manner was observed for T2, the most cytotoxic mycotoxin, followed by NIV, DON, MON, FB1, and ZEA. Regarding mycotoxin mixtures, they mainly showed antagonism on cell viability reduction. Interestingly, at concentrations inhibiting 50% of cell viability, most viable cells exhibited surface marker loss and thus became potentially non-functional. In addition, during the first 18 h of exposure, the effects of mycotoxin mixtures on early cell apoptosis and necrosis were found to be different from those induced by the toxins alone. At the molecular level, after 1 h exposure of individual and combined mycotoxins, the three main MAPK signaling pathways (p38, SAPK/JNK, and ERK1/2) were activated, highlighting a fast reaction of the exposed cells even at low cytotoxicity levels.     

Dualities in plant tolerance to pollutants and their uptake and translocation to the upper plant parts

There is a duality in plant tolerance to pollutants and its response to the pollutants’ stress.On the one hand some plants, (hyper)tolerant to heavy metals, are able to hyperaccumulate these metals in shoots, which could be beneficial for phytoremediation purposes to clean-up soil and water. On the other hand tolerant food crops, exposed to heavy metals in their growth medium, may be dangerous as carriers of toxic metals in the food chain leading to food toxicity. There is an additional duality in plant tolerance to heavy metals and that is in food crops that are tolerant and/or hyperaccumulators, which could be used on one hand for phytoremediation, under controlled conditions and on the other hand for food fortification with essential metals.Similarly, plants are also exposed to a large number of xenobiotic organic pollutants. Because they generally cannot avoid these compounds, plants take up, translocate, metabolize and detoxify many of them. There is a large variability in tolerance (defence) mechanisms against organic pollutants among plant species. This includes production of reductants but also scavenger molecules like ascorbate and glutathione and expression of the P-450 defence system, and superfamilies of the enzymes glutathione- and glucosyl-transferases. Again, with view to organic pollutants, plant detoxification mechanisms might well protect the plant itself, but produce compounds with some deleterious potential for other organisms.In this review we discuss these dualities on the basis of examples of agricultural and ‘wild’ species exposed to metal contaminants (mainly Cd) and organic pollutants. Differences in uptake and translocation of various pollutants and their consequences will be considered. We will separately outline the effects of the organic and non-organic pollutants on the internal metabolism and the detoxification mechanisms and try to indicate the differences between both types of pollutants. Finally the consequences and solutions of these dualities in plant tolerance to pollutants will be discussed.     

Temporal distribution,source apportionment,and pollution assessment of metals in the sediments of Beas river,India

Metal pollution in the fluvial sediments of the rivers has become a severe problem throughout the world. Lower valleys with agricultural land are usually receiving diverse contaminants from various sources that are characterized by constant, bioaccumulative and harmful contaminants. One example is of the Beas river (India) which shows the distribution, contamination, and pollution status of metals in the sediments. In the present study, a cluster analysis and principal component analysis were conducted to assess the impact of anthropogenic activities in sediment metals. Results of contamination factor indicate that there is low contamination, whereas enrichment factor showed that 28.5% metals showed significant pollution during pre-monsoon season, 42.8% metals showed moderate to high pollution during post-monsoon season, and 42.8% metals showed moderate to extreme pollution during the winter season. Pollution index and modified pollution index showed that sediments in the winter season are slightly and critically polluted. The ecological risk factors indicate that 23.8% metals posed moderate to high ecological risk in the sediments.     

Biological detoxification of mycotoxins: a review

Mycotoxins are secondary fungal metabolites and are reported to be carcinogenic, genotoxic, teratogenic, dermato-, nephro- and hepatotoxic. Several studies have shown that economic losses due to mycotoxins occur at all levels of food and feed production, including crop and animal production, processing and distribution. Therefore, there is a great demand for a novel approach to prevent both the formation of mycotoxins in food and feed and the impact of existing mycotoxin contamination. Recently, investigators have reported that many microorganisms including bacteria, yeast, moulds, actinomycetes and algae are able to remove or degrade mycotoxins in food and feed. We have reviewed various strategies for the detoxification of mycotoxins using microorganisms such as bacteria, yeast and fungi.     

Potentialities of fluorescent carbon nanomaterials as sensor for food analysis

Food safety and quality are among the most significant and prevalent research areas worldwide. The fabrication of appropriate technical procedures or devices for the recognition of hazardous features in foods is essential to safeguard food materials. In the recent era, developing high-performance sensors based on carbon nanomaterial for food safety investigation has made noteworthy progress. Hence this review briefly highlights the different detection approaches (colorimetric sensor, fluorescence sensor, surface-enhanced Raman scattering, surface plasmon resonance, chemiluminescence, and electroluminescence), functional carbon nanomaterials with various dimensions (quantum dots, graphene quantum dots) and detection mechanisms. Further, this review emphasizes the assimilation of carbon nanomaterials with optical sensors to identify multiple contaminants in food products. The insights of carbon-based nanomaterials optical sensors for pesticides and insecticides, toxic metals, antibiotics, microorganisms, and mycotoxins detection are described in detail. Finally, the opportunities and future perspectives of nanomaterials-based optical analytical approaches for detecting various food contaminants are discussed.     

Do Current Standards of Practice in Canada Measure What is Relevant to Human Exposure at Contaminated Sites? I: A Discussion of Soil Particle Size and Contaminant Partitioning in Soil

Human health risk estimates for sites with contaminated soils are often based on the assumption that the bulk concentration of substances in outdoor soil samples is a reasonable predictor of exposures via incidental soil ingestion, soil particle inhalation, and dermal absorption. Most underlying conceptual models are grossly simplistic, however, when considered in light of (i) biases in the distribution of contaminants across soil particle sizes, (ii) the size range of particles in soils and dusts that is environmentally available, and (iii) factors that influence desorption from particles and uptake into humans. The available studies indicate that contaminant distribution across soil particle size fractions varies widely between different soil types and contaminant delivery mechanisms, and it cannot be assumed that higher masses of contaminants per unit mass of soil are correlated with smaller particles sizes. Soil data gathered in support of detailed human health risk assessments, therefore, should allow for the examination of distribution across particle sizes of contaminants of concern, and consider those size fractions most critical to human exposure. Soil evaluations for health risk assessments of metals/metalloids should also consider mineralogical characterization.     

Metal‐responsive RNA polymerase extracytoplasmic function (ECF) sigma factors

In order to survive, bacteria must adapt to multiple fluctuations in their environment, including coping with changes in metal concentrations. Many metals are essential for viability, since they act as cofactors of indispensable enzymes. But on the other hand, they are potentially toxic because they generate reactive oxygen species or displace other metals from proteins, turning them inactive. This dual effect of metals forces cells to maintain homeostasis using a variety of systems to import and export them. These systems are usually inducible, and their expression is regulated by metal sensors and signal‐transduction mechanisms, one of which is mediated by extracytoplasmic function (ECF) sigma factors. In this review, we have focused on the metal‐responsive ECF sigma factors, several of which are activated by iron depletion (FecI, FpvI and PvdS), while others are activated by excess of metals such as nickel and cobalt (CnrH), copper (CarQ and CorE) or cadmium and zinc (CorE2). We focus particularly on their physiological roles, mechanisms of action and signal transduction pathways.     

重金属在海洋食物链中的传递

近年来 ,金属在不同海洋食物链中摄食富集的定量研究得到越来越多的关注。自然环境中生物体内金属的浓度并不一定和生物在食物链中所处的营养级有相关关系 ,金属在生物体内的富集还受到生物的同化、排出等过程以及其它生理生化因子的影响。在经典的海洋浮游生物食物链中 (浮游植物→桡足类→鱼类 ) ,桡足类往往可以很有效地排出体内的金属 ,同时鱼类的金属同化率又很低 ,所以该食物链中金属的浓度随食物链水平增加而减少。目前研究发现只有甲基汞和铯 Cs会被食物链所放大。在以腹足动物为顶级捕食者的底栖食物链中 ,因为生物结合金属的效率很高 ,高同化率和低排出率导致金属浓度在生物体内得到放大。重金属在生物体内的可利用性可以通过测定同化率、排出率等参数、并结合考虑生物对该金属的消化行为 ,运用一个简易的动态模型来估算。已有的研究中人们多考虑金属的化学性质对食物链传递的影响。着重介绍了近年来国外对金属在不同海洋食物链 (底栖和浮游 )中的传递的研究成果 ,强调在金属的生物可利用性评估中 ,要充分考虑到动物的生理、生化过程的影响 ,同时也必须认识到不同的海洋生物有着复杂且不同的金属代谢机制     

Pollution and agricultural practices. 2 concepts: acceptable daily dose and chemo-defense

Pollution coming from agricultural practices can exist: pesticides, veterinary drugs, heavy metals but also mycotoxins. However, these contaminants are always at low or trace doses in our environment (foods, water, air, soils). In terms of foods, two concepts have been developed to protect the consumers: acceptable daily intake (ADI) and maximum residue limits (MRL). The impact of this pollution on public health is not evident, in contradiction with the level of fear in the population. Moreover, the distinction made between natural and synthetic substances by the public in terms of toxicity is quite nonsense scientifically. Human beings and all living organisms have a good defence system against chemical xenobiotics which ensures their protection.     

Metal uptake by microalgae: underlying mechanisms and practical applications

Metal contamination of a few aquatic, atmospheric, and soil ecosystems has increased ever since the industrial revolution, owing to discharge of such elements via the effluents of some industrial facilities. Their presence to excessive levels in the environment will eventually lead to serious health problems in higher animals owing to accumulation throughout the food web. Current physicochemical methods available for recovery of metal pollutants (e.g., chemical precipitation, oxidation/reduction, or physical ion exchange) are either expensive or inefficient when they are present at very low concentrations. Consequently, removal of toxic metals by microorganisms has emerged as a potentially more economical alternative. Microalgae (in terms of both living and nonliving biomass) are an example of microorganisms suitable to recover metals and able to attain noteworthy percent removals. Their relatively high metal-binding capacities arise from the intrinsic composition of their cell walls, which contain negatively charged functional groups. Consequently, microalgal cells are particularly efficient in uptake of those contaminants when at low levels. Self-defense mechanisms developed by microalgal cells to survive in metal-containing media and environmental factors that affect their removal (e.g., pH, temperature, and biomass concentration) are reviewed here in a comprehensive way and further discussed in attempts to rationalize this form of remediation vis-a-vis with conventional nonbiological alternatives.     

The impacts of climate change on the annual cycles of birds

Organisms living today are descended from ancestors that experienced considerable climate change in the past. However, they are currently presented with many new, man-made challenges, including rapid climate change. Migration and reproduction of many avian species are controlled by endogenous mechanisms that have been under intense selection over time to ensure that arrival to and departure from breeding grounds is synchronized with moderate temperatures, peak food availability and availability of nesting sites. The timing of egg laying is determined, usually by both endogenous clocks and local factors, so that food availability is near optimal for raising young. Climate change is causing mismatches in food supplies, snow cover and other factors that could severely impact successful migration and reproduction of avian populations unless they are able to adjust to new conditions. Resident (non-migratory) birds also face challenges if precipitation and/or temperature patterns vary in ways that result in mismatches of food and breeding. Predictions that many existing climates will disappear and novel climates will appear in the future suggest that communities will be dramatically restructured by extinctions and changes in range distributions. Species that persist into future climates may be able to do so in part owing to the genetic heritage passed down from ancestors who survived climate changes in the past.     

Molecular and cellular studies on the absorption,function, and safety of food components in intestinal epithelial cells

The intestinal tract comes into direct contact with the external environment despite being inside the body. Intestinal epithelial cells, which line the inner face of the intestinal tract, have various important functions, including absorption of food substances, immune functions such as cytokine secretion, and barrier function against xenobiotics by means of detoxification enzymes. It is likely that the functions of intestinal epithelial cells are regulated or modulated by these components because they are frequently exposed to food components at high concentrations. This review summarizes our research on the interaction between intestinal epithelial cells and food components at cellular and molecular levels. The influence of xenobiotic contamination in foods on the cellular function of intestinal epithelial cells is also described in this review.     

ECOTOXICOLOGICAL PERSPECTIVES IN MARINE MAMMALOGY: RESEARCH PRINCIPLES AND GOALS FOR A CONSERVATION POLICY1

In integrating ecotoxicology and marine mammalogy two principal themes are conceivable: (1) the impact of contaminants on marine mammals and (2) the feasibility of monitoring marine pollution with marine mammals. Monitoring should be an alert procedure, carried out with a sensitive sensor. Uncertainties in interpreting analyses and the low susceptibility of marine mammals to short-term changes in pollution, make them inappropriate for pollution monitoring at present. To answer the question whether pollutants affect marine mammals, the occurrence of contaminants and the response of the animals to those chemicals have to be assessed. In studying the occurrence of contaminants it is essential that atmospheric and riverine input, geochemical processes, and processes involved with the occurrence of natural compounds are considered. To investigate the mechanisms by which pollutants affect physiological processes the kinetics of contaminants in the animals and their clinical toxicity effects have to be studied. Comparative reference data on physical and chemical blood parameters facilitates checking for hematological disorders, electrolyte imbalance, serum biochemistry and hormonal changes. Following such a concept the retrospective study of pollution effects on marine mammals might be turned into a predictive approach.     

Simultaneous and rapid detection of six different mycotoxins using an immunochip

Mycotoxins are highly toxic contaminants in food, animal feed, and commodities. The study has developed an immunochip for quantifying the concentrations of six mycotoxins: aflatoxin B1, aflatoxin M1, deoxynivalenol, ochratoxin A, T-2 toxin, and zearalenone, which were added to drinking water. The complete antigens (Ags) of the mycotoxins were contact printed and immobilized onto agarose-modified glass slides with 12 physically isolated subarrays, based on the reaction of both diffusion and covalent bond. The optimal concentration of each antigen and antibody (Ab) was obtained using an Ag-Ab immunoassay. Based on the indirect competitive immunoassay for the simultaneous detection of six mycotoxins in one single chip, six standard curves with good logistic correlation (R(2)>0.97) were respectively plotted. The working ranges (0.04-1.69, 0.45-3.90, 20.20-69.23, 35.68-363.18, 0.11-1.81, and 0.08-7.47 ng/mL, respectively) were calculated, as well as the median inhibitory concentrations (0.31±0.04, 1.49±0.21, 34.54±1.30, 134.06±11.75, 0.49±0.05, and 1.54±0.22 ng/mL, respectively), when six mycotoxins were detected simultaneously. Finally, the recovery rates in drinking water generally ranged from 80% to 120% on the same chip, with an intra-assay coefficient of variation lower than 15%. We successfully established an immunochip for simultaneous detection of six mycotoxins within 4h, with advantages of using minimal samples and being visually semiquantitative with our naked eyes. In summary, the method could be developed on one single chip for detecting multiple contaminants in actual samples.     

Review: Nutritional ecology of heavy metals

The aim of this review is to focus the attention on the nutrition ecology of the heavy metals and on the major criticisms related to the heavy metals content in animal feeds, manure, soil and animal-origin products. Heavy metals are metallic elements that have a high density that have progressively accumulated in the food chain with negative effects for human health. Some metals are essential (Fe, I, Co, Zn, Cu, Mn, Mo, Se) to maintain various physiological functions and are usually added as nutritional additives in animal feed. Other metals (As, Cd, F, Pb, Hg) have no established biological functions and are considered as contaminants/undesirable substances. The European Union adopted several measures in order to control their presence in the environment, as a result of human activities such as: farming, industry or food processing and storage contamination. The control of the animal input could be an effective strategy to reduce human health risks related to the consumption of animal-origin products and the environmental pollution by manure. Different management of raw materials and feed, animal species as well as different legal limits can influence the spread of heavy metals. To set up effective strategies against heavy metals the complex interrelationships in rural processes, the widely variability of farming practices, the soil and climatic conditions must be considered. Innovative and sustainable approaches have discussed for the heavy metal nutrition ecology to control the environmental pollution from livestock-related activities.     

Potential probiotic strains with heavy metals and mycotoxins bioremoval capacity for application in foodstuffs

Heavy metals and mycotoxins in foodstuffs are one of the major concerns of our world nowadays. Food decontamination with the help of microbial biomass is a cheap, easy, efficient and green method known as bioremoval. Probiotics are able to reduce the availability of heavy metals and toxins in food products. The purpose of this review is to summarize the probiotics and potential probiotics' interesting role in food bio-decontamination. After a brief glance at the definition of potential probiotic strains with bioremoval ability, LABs (lactic acid bacteria) are described as they are the most important groups of probiotics. After that, the role of the main probiotic and potential probiotic strains (Bacillus, Lactobacillus, Lactococcus, Enterococcus, Bifidobacterium, Pediococcus, Propionibacterium, Streptococcus and Saccharomyces cerevisiae) for heavy metals and mycotoxins bioremoval are described. Additionally, the bioremoval mechanism and the effect of some factors in bioremoval efficiency are explained. Finally, the investigations about probiotic and contaminant stability are mentioned. It is worth mentioning that this review article can be exerted in different food and beverage industries to eliminate the heavy metals and mycotoxins in foodstuffs.     

Evaluation of the cytotoxicity of aflatoxin and fumonisin in swine intestinal cells

The coexistence of the aflatoxin (AFB) and fumonisin (FB) has been widely documented in many parts of the world. However, few studies describing the synergy effect of both mycotoxins in vivo and/or in vitro are available. The objective of this study consisted on evaluating the effect of AFB and FB on the morphology, the capacity of cellular proliferation, cytotoxicity and interleukin-8 (IL-8) synthesis in a porcine intestinal epithelial cell line (IPEC-1). Concerning to the cellular morphology it was only affected in the concentrations higher of AFB (50 microM) and FB (500 microM). However, the cellular proliferation, the cellular damage and synthesis of IL-8 they were affected when present in combination the AFB/FB (1.3/3.7; 2/3.7 and 5/10 microM respectively) with that showed by the individual effect of similar concentrations of these mycotoxins (p < 0.05). Our data indicate that the combination of AFB/FB in low concentrations showed a synergy effect, altering the cellular morphophysiology, which can imply in vivo the entrance of other toxins or biological agents for alteration of the intestinal barrier impacting negatively in the human or animal health.     

Molecular mechanisms underlying the toxicity and detoxification of trace metals and metalloids in plants

Plants take up a wide range of trace metals/metalloids(hereinafter referred to as trace metals)from the soil,some of which are essential but become toxic at high concentrations(e.g.,Cu,Zn,Ni,Co),while others are non-essential and toxic even at relatively low concentrations(e.g.,As,Cd,Cr,Pb,and Hg). Soil contamination of trace metals is an increasing problem worldwide due to intensifying human activities.Trace metal contamination can cause toxicity and growth inhibition in plants,as well as accum...     

Mycotoxins and food contamination

The contamination of food and feed by fungi and their toxins (mycotoxins) has to be considered as a serious hazard in the daily live. Mycotoxins are natural contaminants in foods and could induce several syndromes. Many mycotoxicosis are described. The control and surveillance of mycotoxins involve the carrying out of surveys, toxicological studies and institution of regulations.