Presence of the neurotoxin β-N-methylamino-L-alanine in irrigation water and accumulation in cereal grains with human exposure risk

The present study demonstrates the presence of the neurotoxin β-N-methylamino-L-alanine and its cyanobacterial producers in irrigation water and grains of some cereal plants from farmlands irrigated with Nile River water in Egypt. BMAA detected by LC-MS/MS in phytoplankton samples was found at higher concentrations of free form (0.84-11.4 μg L-1) than of protein-bound form (0.16-1.6 μg L-1), in association with the dominance of cyanobacteria in irrigation water canals. Dominant cyanobacterial species isolated from these irrigation waters including Aphanocapsa planctonica, Chroococcus minutus, Dolichospermum lemmermanni, Nostoc commune, and Oscillatoria tenuis were found to produce different concentrations of free (4.8-71.1 µg g-1 dry weight) and protein-bound (0.1-11.4 µg g-1 dry weight) BMAA. In the meantime, BMAA was also detected in a protein-bound form only in grains of corn (3.87-4.51 µg g-1 fresh weight) and sorghum (5.1-7.1 µg g-1 fresh weight) plants, but not in wheat grains. The amounts of BMAA accumulated in these grains correlated with BMAA concentrations detected in relevant irrigation water canals. The presence of BMAA in cereal grains would constitute a risk to human and animal health upon consumption of contaminated grains. The study, therefore, suggests continuous monitoring of BMAA and other cyanotoxins in irrigation waters and edible plants to protect the public against exposure to such potent toxins.

Enhanced edible plant production using nano-manganese and nano-iron fertilizers: Current status, detection methods and risk assessment

BACKGROUND

Nanotechnology offers many benefits in the globally important field of food production and human nutrition, particularly by implementing agricultural nanoproducts. Of these, edible plant fertilizers enriched with nanosized forms of essential metals, Mn and Fe, are growing in importance with the advantages of enhanced action on plant roots.

SCOPE AND APPROACH

This review focuses on the importance of tracking the bioaccumulation and biodistribution of these pertinent nanofertilizers. An emphasis is given to the critical analysis of the state-of-the-art analytical strategies to examine the Mn and Fe nanoparticles in edible plant systems as well as to shedding light on the vast gap in the methodologies dedicated to the speciation, in vitro simulation, and safety testing of these promising nanomaterials. Also provided are guidances for the food chemists and technologists on the lights and shadows of particular analytical approaches as a matter of authors' expertise as analytical chemists.

KEY FINDINGS AND CONCLUSIONS

While the use of nanotechnology in agriculture seems to be growing increasingly, there is still a lack of analytical methodologies capable of investigating novel Mn- and Fe-based nanomaterials as potential fertilizers. Only the advent of reliable analytical tools in the field could bridge the gaps in our knowledge about processes in which those materials participate in the plant systems and their effects on crop production and quality of the produced food.

Accumulation and risk assessment of antibiotics in edible plants grown in contaminated farmlands: A review

The extensive occurrence of antibiotics in farmland soil might threaten food safety. The bioaccumulation potential of antibiotics in edible vegetables and crops grown under realistic farming scenarios was reviewed and the human health risk was assessed. A total of 51 antibiotics were documented in 37 species of daily consumed crops. Among different classes of antibiotics, tetracyclines (TCs) exhibited higher residue levels in plants than quinolones (QNs), sulfonamides (SAs), and macrolides (MLs), with median values ranging from 5.10 to 15.4 μg/kg dry weight. The favored accumulation of TCs in plants was probably linked to their relatively higher residual concentrations in soils and greater bioconcentration factors. Compared with the plants grown in open field, accumulation of antibiotics was higher in plant grown under greenhouse condition, probably due to the higher residue levels of antibiotics in the greenhouse soil with intensive application of manure. Cocktails of antibiotics were investigated in potato, corn, carrot, tomato, lettuce, and wheat. Among them, corn exhibited relatively high median concentrations of antibiotics (0.400-203 μg/kg dry weight). Antibiotics tended to accumulate in plant root and their concentrations in fruit were generally low. Risk assessment revealed that human health risk was under the alert line through the daily consumption of antibiotic contaminated vegetables and food crops.

Socioeconomic factors influencing knowledge and consumption of food plants by a human group in a mountainous environment in the semiarid region of Bahia, Northeast Brazil

BACKGROUND

The relationship of people with natural resources is guided by different sociocultural, ecological and evolutionary factors. Regarding food plants, it is not different. Studies around the world have evaluated the effects of socioeconomic factors, such as age, gender, income, profession, education level, time of residence, ethnic diversity, religion, festive rituals, access to urban areas and migrations. In this sense, the objective of the present study was to characterize the diversity of knowledge and use of food plants by people from Serra dos Morgados and evaluate if the socioeconomic factors influence knowledge and consumption of food plants in the community.

METHODOLOGY

This research was conducted in the village of Serra dos Morgados, municipality of Jaguarari, Bahia, with the purpose of evaluating the factors that influence in the knowledge and use of food plants. Socioeconomic data such as age, gender, time of residence, and monthly income were collected. The free list technique was applied during the collection of ethnobotanical data in order to analyze the preference of the plants based on the salience index (SI). To analyze the factors that influence knowledge and use forms, we used GLM Lasso.

RESULTS

A total of 33 people were interviewed, 8 men and 25 women; their age ranged from 30 to 82 years. People cited 98 species of plants, 41 species being identified of spontaneous occurrence. The plant with the highest salience index (SI) was "cheirosa" (Psidium ganevii) (SI = 0.5679), followed by "massaranduba" (Micropholis sp.) (SI = 0.4323); "araça" (Campomanesia guazumifolia) (SI = 0.3320); and "cambuí" (Siphoneugena sp.) (SI = 0.3144).

CONCLUSIONS

The main factors that influence knowledge and use forms in the locality were family income and the collection site, with homegardens cited as the preferred area for collection of food plants. This study provided an overview related to potentially important species for a community located in a region where there are few ethnobiological studies. The results presented here can be used in future studies, providing clues for investigations. Also, there is a contribution to the conservation of biocultural aspects related to the use of food plants in a community living in mountainous regions.

Inhibition of the SARS-CoV-2 3CLpro main protease by plant polyphenols

The abundance of polyphenols in edible plants makes them an important component of human nutrition. Considering the ongoing COVID-19 pandemic, a number of studies have investigated polyphenols as bioactive constituents. We applied in-silico molecular docking as well as molecular dynamics supported by in-vitro assays to determine the inhibitory potential of various plant polyphenols against an important SARS-CoV-2 therapeutic target, the protease 3CL^pro. Of the polyphenols in initial in-vitro screening, quercetin, ellagic acid, curcumin, epigallocatechin gallate and resveratrol showed IC₅₀ values of 11.8 µM to 23.4 µM. In-silico molecular dynamics simulations indicated stable interactions with the 3CL^pro active site over 100 ns production runs. Moreover, surface plasmon resonance spectroscopy was used to measure the binding of polyphenols to 3CL^pro in real time. Therefore, we provide evidence for inhibition of SARS-CoV-2 3CL^pro by natural plant polyphenols, and suggest further research into the development of these novel 3CL^pro inhibitors or biochemical probes.

Traditional knowledge of edible plants used as flavoring for fish-grilling in Southeast Guizhou, China

BACKGROUND

The local Dong people in Qiandongnan Prefecture, Guizhou Province, China, with rich biocultural diversity, have developed the traditional rice-duckweed-fish-duck agroecosystem (RDFDA) to support biodiversity conservation and to meet food and cultural needs. However, there is still not much research on traditional ecological knowledge (TEK) in this area. In particular, there is a lack of traditional knowledge of edible plants used by the Dong people as flavoring to grill fish (Cyprinus carpio) collected from RDFDA, which is extremely valuable in their traditional culture. The study focused on documenting plant species used in grilling fish and analyzing the status of its TEK.

METHODS

Twenty-one sampling points of three Dong minority villages in Qiandongnan were selected for the research. The local TEK associated with plant resources for fish-grilling was recorded through free listing and semi-structured interviews. Fidelity level (FL) and ethnoecological importance value (EIV) indicators were designed to determine the socioeconomic influence of TEK. The non-metric multidimensional scaling (NMDS) method was used to evaluate the differentiation of edible plant species distribution in dissimilar accessibility types.

RESULTS

A total of 430 people were interviewed about grilled fish, of whom 75% were men and 85% were farmers. Thirty-four edible plants were documented for fish-grilling in three Dong villages. They belong to 16 plant families, such as Apiaceae, and Asteraceae. The life forms included herbaceous (76%), shrubs (18%) and trees (6%). Leaves are the most commonly used part of for grilling fish, followed by aerial parts, and whole plants. Among these edible plants, Allium hookeri, A. macrostemon and Houttuynia cordata with the highest fidelity level (100%) were cited as edible plants for grilling fish by all informants. The NMDS showed different accessibility types of collection sites, with different importance values. Paddy rice field edge (2.03) has the highest value, followed by forest-farming ecotone (1.74), streamsides (1.71) and woodland (0.48).

CONCLUSION

The purpose of this study was to investigate the traditional knowledge of edible plant materials used by the Dong people for grilling fish. The results demonstrate the strong connection between local people, the bio-environment and agroecosystem services. The survey and comparative analysis revealed that plant species with high FL values may be potential sources of natural flavors.

Open source software toolchain for automated non-targeted screening for toxins in alternative foods

Previous published methods for non-targeted screening of toxins in alternative foods such as leaf concentrate, agricultural residues or plastic fed to biological consortia are time consuming and expensive and thus present accessibility, as well as, time-constraint issues for scientists from under resourced settings to identify safe alternative foods. The novel methodology presented here, utilizes a completely free and open source software toolchain for automatically screening unknown alternative foods for toxicity using experimental data from ultra-high-pressure liquid chromatography and mass spectrometry. The process uses three distinct tools (mass spectrometry analysis with MZmine 2, formula assignment with MFAssignR, and data filtering with ToxAssign) enabling it to be modular and easily upgradable in the future. MZmine 2 and MFAssignR have been previously described, while ToxAssign was developed here to match the formulas output by formula assignment to potentially toxic compounds in a local table, then look up toxic data on the Open Food Tox Database for the matched compounds. This process is designed to fill the gap between food safety analysis techniques and developing alternative food production techniques to allow for new methods of food production to be preliminarily tested before animal testing. The methodology was validated against a previous method using proprietary commercial software. The new process identifies all of the toxic elements the previous process identified with more detailed information than the previous process was able to provide automatically.•Efficient analysis to find potentially toxic compounds in alternative foods and resilient foods.•Identification of potentially unsafe products without the use of live animal testing.•Modular free and open source design to allow for upgrading or fitting of user needs.

Bioaccumulation and human health risk assessment of heavy metals in food crops irrigated with freshwater and treated wastewater: a case study in Southern Cairo, Egypt

Food safety has often attracted attention worldwide. Few studies have investigated the heavy metal (HM) pollution and health risk assessment of crops and vegetables. The current work was conducted to evaluate the human risk assessment of HM (Cu, Cd, Cr, Pb, and Zn) in radish, lettuce, tomato, onion, turnip, squash, okra, sunflower, Jews mallow, and garden rocket cultivated in treated wastewater (TWW)-irrigated sites as compared with those cultivated in freshwater (FW)-irrigated sites. Irrigation water, soil, and different plants were collected from 6 farmlands irrigated with TWW and two agricultural sites irrigated with FW (Nile river). Heavy metal transfer factor (HMTF), chronic daily intake of metals (CDIM), health hazard risk (HR), and health hazard index (HI) were estimated. The results showed that the tested HM levels in FW and TWW were below the Food and Agriculture Organization (FAO) and Egyptian standards recommended for irrigation. In soil samples, HM levels were below the permissible limits for both tested sites. The HM in soil and plants grew in TWW-irrigated sites possessed multiple levels higher than those grown in FW-irrigated sites. Among different plants, HM levels in the edible parts of plants grown in TWW-irrigated sites followed in decreasing order: tomato > sunflower >Jew's mallow = turnip = squash > lettuce > okra = radish > onion > garden rocket. The mean CDIM and HR values of plants irrigated using TWW were higher than those irrigated using FW. Furthermore, HR values for all plants grown in polluted and unpolluted sites were < 1 except Cd in plants grown in the TWW-irrigated farmlands. The mean HI for radish, lettuce, tomato, onion, turnip, squash, okra, sunflower, Jews mallow, and garden rocket grown in TWW-irrigated sites were 2.08, 2.39, 1.76, 1.53, 2.08, 1.80, 2.03, 1.91, 1.82, and 1.44 (for adult), and 2.39, 2.75, 2.71, 1.75, 2.38, 2.06, 2.33, 2.69, 2.10, and 1.65 (for children). Plants irrigated with TWW showed a higher HMTF than plants irrigated with FW. Jew's mallow and okra irrigated with TWW had a maximum HMTF. Consequently, different practical measures can be taken to minimize the HM levels in agricultural foodstuffs. These measures include preventing the excessive application of pesticides and fertilizers for crop production and continuous monitoring of different foodstuffs in the market.

Exogenous application of melatonin to plants, algae, and harvested products to sustain agricultural productivity and enhance nutritional and nutraceutical value: A meta-analysis

Melatonin is produced by plants, algae, and animals. Worldwide studies show diverse positive effects of exogenous melatonin on plants, edible plant products, and algae, but the potential of melatonin to enhance food and feed systems through these positive effects remains largely unexplored. Through a meta-analysis of about 25,000 observations, we show for the first time that exogenous application of melatonin significantly increases crop productivity and yields, and enhances the nutritional and nutraceutical value of edible plant products and algae by regulating diverse biological functions. We demonstrate that melatonin can improve plants, edible plant products, and algae under various current climate change scenarios, environmental pollution factors, and other stresses by about 7% to nearly 30%, on average, depending on the stressor. We also analyze various technical/methodological factors influencing the desired outcomes and identify conditions that offer optimal enhancement. We show that the positive effect of melatonin on plants and edible plant products varies among species, genera, and families, and strongly depends on the concentration of melatonin and treatment duration. The effect of melatonin is slightly lower on the monocot clade Commelinids than on the eudicot clades Asterids and Rosids. We also show that its stimulatory effect on plants depends on cultivation system, with a larger effect obtained in hydroponic systems. However, it does not depend on application stage (seed or vegetative), application route (foliage, roots, or seed), and whether the cultivation system is ex vivo or in vivo. This is the first meta-analysis examining the effects of melatonin on plants, edible plant products, and algae, and offers a scientific and technical roadmap facilitating sustainable food and feed production through the application of exogenous melatonin.

Toxic metal phytoextraction potential and health-risk parameters of some cultivated plants when grown in metal-contaminated river sediment of Danube, near an industrial town

Toxic metal phytoextraction potential of some higher plants, the white mustard (Sinapis alba L.), perennial rye grass (Lolium perenne L.) and also two cultivated plants, as green pea (Pisum sativum L. var. Rajnai törpe), radish (Raphanus sativus L. var. Szentesi óriás vaj), was studied in a field experiment, along the river Danube in close vicinity of an industrial town, Dunaújváros, Hungary. Soil/sediment and the various plant organs (leaves, stems and roots) were assessed for the contamination with some potentially toxic elements (PTE), such as the cadmium (Cd), nickel (Ni), copper (Cu), and zinc (Zn). It was found that Cd and Ni concentration was below, while the Cu and Zn elements were above the Hungarian permissible limits in each of the studied soil/sediment samples. Bioconcentration factor (BAF) was less than 1 in the shoot biomass of test plant samples and followed the order of Cu > Zn > Cd and Ni. Phytoremediation potential of selected test plants was found to be rather limited. The translocation factor (TF) was more than 1 for Cu and Zn elements, at each test plants. Cadmium was translocated into the leaves in case of the radish, only. Considering of the potential human daily intake of metals (DIM), it was less than 1 both for the adults and for the children. Health risk index (HRI) values of children, however, were higher than 1 for the Cd in case of radish, and for Zn and Cu in case of the pea. Results suggest that consumption of these plants grown in gardens of contaminated sediments can result in some risks for citizens in the industrial town of Dunaújváros. Further studies are required to identify appropriate plants with greater toxic metal phytoextraction potential.

Mapping Early Pleistocene environments and the availability of plant food as a potential driver of early Homo presence in the Guadix-Baza Basin (Spain)

The Guadix-Baza Basin, in SE Spain, harbors hominin fossils and lithic artifacts dated to ca. 1.4-1.3 Ma, representing the first hominin habitat in the Iberian Peninsula and possibly in Western Europe. Recent palynological studies have described a high diversity of plant taxa and biomes existing in the basin at the time of hominin presence. However, the relationship between these hominins and their environment has not been fully explored. Two novel methodologies are developed. The first method maps the distribution of the Early Pleistocene vegetation units based on paleobotanical and paleogeographic data. The second method assesses the availability of edible plant parts using a combination of Early Pleistocene and modern taxa lists. The resulting vegetation maps reveal a great diversity of vegetation types. During dry (glacial) periods, the vegetation of the basin was represented mostly by steppes, with the appearance of forested vegetation only in the mountainous regions. During humid (interglacial) periods, Mediterranean woodlands represented the dominant vegetation, accompanied by deciduous and conifer forests in the areas of higher altitude. The lake system present in the basin also allowed for the presence of marshland vegetation. The assessment of the availability of edible plant parts reveals that early Homo could have found a high number of resources in marshland and riparian environments throughout the year. Mediterranean woodlands and deciduous forests also provided numerous edible plant parts. During dry periods, the availability of plant resources decreased heavily, but the prevalence of marshland and riparian vegetation and of forested vegetation in the areas of higher altitude could have sustained hominin communities during harsher climatic periods. However, the disappearance of the lake system and an increase of aridity after the Mid-Pleistocene Transition and during the Middle Pleistocene probably led to an impoverishment of plant resources available to early Homo in the Guadix-Baza Basin.

Metabolic profiles and non-targeted LC-MS/MS approach as a complementary tool to targeted analysis in assessment of plant exposure to pesticides

Liquid chromatography coupled with tandem mass spectrometry was employed for the detection of pesticides (thiamethoxam, lambda-cyhalothrin, deltamethrin, and metalaxyl) and their metabolites in Raphanus sativus var. longipinnatus exposed to these compounds under experimental conditions. Metalaxyl (0.008 mg/kg), metalaxyl acid (0.009 mg/kg), and (+)-trans-chrysanthemic acid (0.098 mg/kg) were identified in the plants exposed to the individual pesticides and their metabolites. Non-targeted analysis revealed the presence of thiamethoxam, lambda-cyhalothrin, and deltamethrin metabolites in plants exposed to these substances, despite the fact that the pesticide concentrations were below the analytical method's limit of quantification (0.005-0.006 mg/kg). Based on the non-targeted screening, non-specific (leucine and tyramine) and specific (epinephrine, dopamine, tryptamine, and serotonin) markers of plant exposure to the mentioned stress-inducing compounds were detected. These findings prove that non-targeted analysis is an indispensable tool for determining plants' exposure to pesticides, even when the parent compound has been completely metabolized.

Therapeutic opportunities of edible antiviral plants for COVID-19

The pandemic of Serious Acute Respiratory Syndrome Corona Virus-2 (SARS-CoV-2) that produces corona virus disease (COVID-19) has challenged the entire mankind by rapidly spreading globally in 210 countries affecting over 25 million people and about 1 million deaths worldwide. It continues to spread, afflicting the health system globally. So far there is no remedy for the ailment and the available antiviral regimens have been unsatisfactory for the clinical outcomes and the mode of treatment has been mainly supportive for the prevention of COVID-19-induced morbidity and mortality. From the time immortal the traditional plant-based ethno-medicines have provided the leads for the treatment of infectious diseases. Phytopharmaceuticals have provided potential and less toxic antiviral drugs as compared to conventional modern therapeutics which are associated with severe toxicities. The ethnopharmacological knowledge about plants has provided food supplements and nutraceuticals as a promise for prevention and treatment of the current pandemic. In this review article, we have attempted to comprehend the information about the edible medicinal plant materials with potential antiviral activity specifically against RNA virus which additionally possess property to improve immunity along with external and internal respiration and exhibit anti-inflammatory properties for the prevention and treatment of the disease. This will open an arena for the development of novel nutraceutical herbal formulations as an alternative therapy that can be used for the prevention and treatment of COVID-19.

Common garlic (Allium sativum L.) has potent Anti-Bacillus anthracis activity

ETHNOPHARMACOLOGICAL RELEVANCE

Gastrointestinal anthrax, a disease caused by Bacillus anthracis, remains an important but relatively neglected endemic disease of animals and humans in remote areas of the Indian subcontinent and some parts of Africa. Its initial symptoms include diarrhea and stomachache. In the current study, several common plants indicated for diarrhea, dysentery, stomachache or as stomachic as per traditional knowledge in the Indian subcontinent, i.e., Aegle marmelos (L.) Correa (Bael), Allium cepa L. (Onion), Allium sativum L. (Garlic), Azadirachta indica A. Juss. (Neem), Berberis asiatica Roxb. ex DC. (Daruharidra), Coriandrum sativum L. (Coriander), Curcuma longa L. (Turmeric), Cynodon dactylon (L.) Pers. (Bermuda grass), Mangifera indica L. (Mango), Morus indica L. (Black mulberry), Ocimum tenuiflorum L. (Ocimum sanctum L., Holy Basil), Ocimum gratissimum L. (Ram Tulsi), Psidium guajava L. (Guava), Zingiber officinale Roscoe (Ginger), were evaluated for their anti-Bacillus anthracis property. The usage of Azadirachta indica A. Juss. and Curcuma longa L. by Santals (India), and Allium sp. by biblical people to alleviate anthrax-like symptoms is well documented, but the usage of other plants is traditionally only indicated for different gastrointestinal disturbances/conditions.

AIM OF THE STUDY

Evaluate the above listed commonly available edible plants from the Indian subcontinent that are used in the traditional medicine to treat gastrointestinal diseases including those also indicated for anthrax-like symptoms for the presence of potent anti-B. anthracis activity in a form amenable to use by the general population in the endemic areas.

MATERIALS AND METHODS

Aqueous extracts made from fourteen plants indicated above were screened for their anti-B. anthracis activity using agar-well diffusion assay (AWDA) and broth microdilution methods. The Aqueous Garlic Extract (AGE) that displayed most potent anti-B. anthracis activity was assessed for its thermostability, stability under pH extremes encountered in the gastrointestinal tract, and potential antagonistic interaction with bile salts as well as the FDA-approved antibiotics used for anthrax control. The bioactive fractions from the AGE were isolated by TLC coupled bioautography followed by their characterization using GC-MS.

RESULTS

Garlic (Allium sativum L.) extract was identified as the most promising candidate with bactericidal activity against B. anthracis. It consistently inhibited the growth of B. anthracis in AWDA and decreased the viable colony-forming unit counts in liquid-broth cultures by 6-logs within 6-12 h. The AGE displayed acceptable thermostability (>80% anti-B. anthracis activity retained on incubation at 50 °C for 12 h) and stability in gastric pH range (2-8). It did not antagonize the activity of FDA-approved antibiotics used for anthrax control. GC-MS analysis of the TLC separated bioactive fractions of AGE indicated the presence of previously unreported constituents such as phthalic acid derivatives, acid esters, phenyl group-containing compounds, steroids etc. CONCLUSION: The Aqueous Garlic Extract (AGE) displayed potent anti-B. anthracis activity. It was better than that displayed by Azadirachta indica A. Juss. (Neem) and Mangifera indica L., while Curcuma longa L. (Turmeric) did not show any activity under the assay conditions used. Further work should be undertaken to explore the possible application of AGE in preventing anthrax incidences in endemic areas.

On the elemental composition of the Mediterranean euhalophyte Salicornia patula Duval-Jouve (Chenopodiaceae) from saline habitats in Spain (Huelva, Toledo and Zamora)

A complete survey is presented on the inorganic composition of the euhalophyte annual succulent species Salicornia patula (Chenopodiaceae), including materials from the Iberian Peninsula, littoral-coastal Tinto River basin areas (SW Spain: Huelva province), and mainland territories (NW and central Spain: Zamora and Toledo provinces). The aim of this contribution is to characterize the elemental composition of the selected populations and their soils and compare the relationship between them and the macro- and micronutrient plant intake; all these nutrients may allow this species to be considered an edible plant. Using analytical techniques such as ICP-MS (inductively coupled plasma mass spectrometry), our results revealed high values of Na and K followed by Ca, Mg, Fe and Sr in stems. These data demonstrate the importance of annual halophytic species as edible plants and their potential uses in phytoremediation procedures involving soils with certain heavy metals (Pb, Sr, As, Cu, Zn).

Medicinal and edible plants used by the Lhoba people in Medog County, Tibet, China

ETHNOPHARMACOLOGICAL RELEVANCE

The Lhoba people are a small, ancient, tribal ethnic group from the Himalayas and are located in the Tibet Autonomous Region of China. Medog County is rich in biocultural diversity. For a long time, Medog has been almost isolated from the outside world. The Lhoba people, who live in Medog, have maintained a relatively unique lifestyle and have accumulated rich traditional knowledge (TK), especially about medicinal and edible plants. Currently, there is very little documentation of the plants traditionally used by the local Lhoba communities.

AIM OF THE STUDY

Our investigation aimed to (i) document the species of medicinal and food plants used by the Lhoba people in Medog County, Tibet, China; (ii) screen the most important plant taxa for specific medicines, and identify the aliments treated to further contribute to drug and food supplement research; and (iii) examine whether the ethnobotanical knowledge of the Lhoba is similar among different tribes and discuss traditional uses in the health practices and livelihoods of the local communities.

METHODS

Ethnobotanical data were recorded through semi-structured interviews, guided field trips, and quantitative analysis. The informant consensus factor (FIC) was used as a quantitative index.

RESULTS

Ninety-one informants (61 men and 30 women) were interviewed. A total of 75 species, including 37 medicinal plants for 14 categories of diseases and 57 edible plants from six types of food, were recorded. Among the usage types of medicinal plants, the highest FIC values were recorded for antidotes (FIC = 0.98), anthelmintics (FIC = 0.98), and treatments of gastrointestinal problems (FIC = 0.93). The FIC values for different types of edible plants were very similar. The most frequently used medicinal and food plants in the studied communities are Zanthoxylum motuoense, Crassocephalum crepidioides, and Swertia nervosa. According to the comparative study, few differences in the use of wild plants were found. There appeared to be more overlapping species between two Lhoba tribes in Medog, named Mixingba and Miguba, with 46 (61%) common species, compared with the Bo'gaer tribe in Milin, which had only two (2.7%) overlapping species. This might be due to the different geographical environments, vegetation types, and different influences of other ethnic cultures.

CONCLUSIONS

The Lhoba people in Medog County, Tibet, China, have rich TK about the uses of wild plants. However, the TK is seriously threatened due to environmental degradation and acculturation, and it showed signs of being forgotten and abandoned by the younger generation. Therefore, measures are urgently needed to document and protect the TK of the uses of the wild plant resources; and (i) the most frequently used medicinal and/or edible plants; (ii) the plants used to treat the most commonly mentioned diseases; and (iii) the endemic species that are widely used in Medog, which should be assessed for their potential future as food supplements and therapeutic products.

Synergistic effects of edible plants with light environment on the emotion and sleep of humans in long-duration isolated environment

The emotion and sleep-related problems of humans who are on mission of deep-space and deep-sea exploration are topics of special interest because of the isolated environment. Effective regulatory approaches should be developed to manage the positive emotions and sleep quality in a long-duration isolated environment. The results reported that emotion and sleep were closely linked to each other because plants could significantly regulate humans' emotion and sleep through their own color and fragrance. Additionally, the light conditions prevailing in that location also had significant influence on humans' emotion and sleep. There have been few reports on the synergistic effects of plants with light environment on humans' physical and mental health. In this research, three species of edible plants and three color temperature levels that were commonly used in people's living environment were selected. Then orthogonal tests were conducted in the cabins of "Lunar Palace I" in the middle of the third phase of the "Lunar Palace 365″ experiment, and salivary cortisol levels, emotion, and sleep conditions of the volunteers were measured. The results showed that in the long-duration isolated environment, strawberry had a better effect than purple rape and coriander on improving positive emotion. Exposure to coriander before bedtime might help people to rapidly go to sleep, increase sleep integrity, and sleep efficiency in the isolated environment. Moreover, there appeared to be a positive synergistic effect of edible plants with light environment on micro-awakening index and sleep efficiency. These results provided a scientific basis for improving the physiological and psychological health of people in the long-duration isolated environment by changing the light environment with appropriate plants.

Heavy Metal Threats to Plants and Soil Life in Southern Africa: Present Knowledge and Consequences for Ecological Risk Assessment

In recent times there has been remarkable development in the field of soil ecotoxicology and risk assessment (RA) models. It is, however, debatable if these RA models are robust representatives for worldwide relevance. In order to investigate this, the current overview aims to address heavy metal threats to soil life in southern Africa by investigating present knowledge and consequences for RA using research in southern Africa as a case. To this end, the focus is on southern African soils, soil life and living conditions. To critically discuss these issues, we report on extensive research conducted in the southern African context and looked how comparable these findings are to RA models employed in the western world. This is done by providing an inventory of selected studies focused on the ecotoxicity of metals towards soil life. It is concluded that there is a dearth of information on southern African soil life, most of which are laboratory-based studies carried out by a handful of researchers. Future research incorporating the available information into a soil ecosystem assessment procedure is paramount. It is recommended that a starting point to tackle this might be the development of holistic sight-specific guidelines for ecological risk assessment at larger spatial scales (km²) which takes into cognizance landscapes, vegetation and faunal characteristics.

Diversity and use of medicinal plants for soup making in traditional diets of the Hakka in West Fujian, China

BACKGROUND

Wild edible and medicinal plants were an important component of traditional diets and continue to contribute to food security, nutrition, and health in many communities globally. For example, the preparation and consumption of soup made of medicinal plants for promoting health and preventing disease are a key component of the traditional diets of the Hakka socio-linguistic group of China's West Fujian Province. As environmental and socio-economic factors drive the shift away from traditional diets, there is a need for ethnobotanical documentation of the diversity of wild edible and medicinal plants as well as associated knowledge and practices.

METHOD

Ethnobotanical surveys were conducted in Hakka communities in West Fujian Province between 2017 and 2018 to document plants used in medicinal soups as well as associated traditional ecological knowledge, practices, and conservation status. Surveys included semi-structural interviews, key informant interviews, participatory rural appraisal, and focus group discussions. Quantitative indices, including cultural food significance index (CFSI) and relative frequency of citation (RFC), were calculated to evaluate the importance of documented plants to Hakka communities. The species with the highest CFSI and RFC values were ranked by informants and further evaluated according to their individual properties and growth environment.

RESULTS

A total of 42 medicinal plant species, belonging to 25 families and 41 genera, were documented for making soup by the Hakka. The Asteraceae botanical family was the most prevalent, and their root or the entire plant is used for soup making. Informants incorporate different ingredients in soups for their flavors as well as medicinal properties on the basis of the local ethnonutrition system. The most prevalent medicinal uses of the documented plants for making soups were used for clearing inner heat (58.1% of the species), treating inflammation (37.2%), and counteracting cold in the body (20.9%). Informants perceived that the medicinal properties of soup-making plants are influenced by the time of harvest, the local environment, and the climate.

CONCLUSION

Efforts are needed to preserve the ecological knowledge associated with traditional diets towards supporting both environmental and human well-being in rapidly developing communities experiencing the nutrition transition and biodiversity loss.

Plant-derived secondary metabolites as the main source of efflux pump inhibitors and methods for identification

The upsurge of multiple drug resistance (MDR) bacteria substantially diminishes the effectiveness of antibiotic arsenal and therefore intensifies the rate of therapeutic failure. The major factor in MDR is efflux pump-mediated resistance. A unique pump can make bacteria withstand a wide range of structurally diverse compounds. Therefore, their inhibition is a promising route to eliminate resistance phenomenon in bacteria. Phytochemicals are excellent alternatives as resistance-modifying agents. They can directly kill bacteria or interact with the crucial events of pathogenicity, thereby decreasing the ability of bacteria to develop resistance. Numerous botanicals display noteworthy efflux pumps inhibitory activities. Edible plants are of growing interest. Likewise, some plant families would be excellent sources of efflux pump inhibitors (EPIs) including Apocynaceae, Berberidaceae, Convolvulaceae, Cucurbitaceae, Fabaceae, Lamiaceae, and Zingiberaceae. Easily applicable methods for screening plant-derived EPIs include checkerboard synergy test, berberine uptake assay and ethidium bromide test. In silico high-throughput virtual detection can be evaluated as a criterion of excluding compounds with efflux substrate-like characteristics, thereby improving the selection process and extending the identification of EPIs. To ascertain the efflux activity inhibition, real-time PCR and quantitative mass spectrometry can be applied. This review emphasizes on efflux pumps and their roles in transmitting bacterial resistance and an update plant-derived EPIs and strategies for identification.

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Active efflux as the main resistance strategy in bacteria.

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Phytochemicals as promising alternatives against efflux pumps-mediated MDR.

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Herbals-based efflux pump inhibitors screening, the methods.

Uptake, translocation, size characterization and localization of cerium oxide nanoparticles in radish (Raphanus sativus L.)

Due to their unique physical and chemical properties, the production and use of cerium oxide nanoparticles (CeO₂ NPs) in different areas, especially in automotive industry, is rapidly increasing, causing their presence in the environment. Released CeO₂ NPs can undergo different transformations and interact with the soil and hence with plants, providing a potential pathway for human exposure and leading to serious concerns about their impact on the ecosystem and human organism. This study investigates the uptake, bioaccumulation, possible translocation and localization of CeO₂ NPs in a model plant (Raphanus sativus L.), whose edible part is in direct contact with the soil where contamination is more likely to happen. The stability of CeO₂ NPs in plant growth medium as well as after applying a standard enzymatic digestion procedure was tested by single particle ICP-MS (SP-ICP-MS) showing that CeO₂ NPs can remain intact after enzymatic digestion; however, an agglomeration process was observed in the growth medium already after one day of cultivation. An enzymatic digestion method was next used in order to extract intact nanoparticles from the tissues of plants cultivated from the stage of seeds, followed by size characterization by SP-ICP-MS. The results obtained by SP-ICP-MS showed a narrower size distribution in the case of roots suggesting preferential uptake of smaller nanoparticles which led to the conclusion that plants do not take up the CeO₂ NPs agglomerates present in the medium. However, nanoparticles at higher diameters were observed after analysis of leaves plus stems. Additionally, a small degree of dissolution was observed in the case of roots. Finally, after CeO₂ NPs treatment of adult plants, the spatial distribution of intact CeO₂ NPs in the radish roots was studied by laser ablation ICP-MS (LA-ICP-MS) and the ability of NPs to enter and be accumulated in root tissues was confirmed.

Uptake, translocation, size characterization and localization of cerium oxide nanoparticles in radish (Raphanus sativus L.)

Due to their unique physical and chemical properties, the production and use of cerium oxide nanoparticles (CeO₂ NPs) in different areas, especially in automotive industry, is rapidly increasing, causing their presence in the environment. Released CeO₂ NPs can undergo different transformations and interact with the soil and hence with plants, providing a potential pathway for human exposure and leading to serious concerns about their impact on the ecosystem and human organism. This study investigates the uptake, bioaccumulation, possible translocation and localization of CeO₂ NPs in a model plant (Raphanus sativus L.), whose edible part is in direct contact with the soil where contamination is more likely to happen. The stability of CeO₂ NPs in plant growth medium as well as after applying a standard enzymatic digestion procedure was tested by single particle ICP-MS (SP-ICP-MS) showing that CeO₂ NPs can remain intact after enzymatic digestion; however, an agglomeration process was observed in the growth medium already after one day of cultivation. An enzymatic digestion method was next used in order to extract intact nanoparticles from the tissues of plants cultivated from the stage of seeds, followed by size characterization by SP-ICP-MS. The results obtained by SP-ICP-MS showed a narrower size distribution in the case of roots suggesting preferential uptake of smaller nanoparticles which led to the conclusion that plants do not take up the CeO₂ NPs agglomerates present in the medium. However, nanoparticles at higher diameters were observed after analysis of leaves plus stems. Additionally, a small degree of dissolution was observed in the case of roots. Finally, after CeO₂ NPs treatment of adult plants, the spatial distribution of intact CeO₂ NPs in the radish roots was studied by laser ablation ICP-MS (LA-ICP-MS) and the ability of NPs to enter and be accumulated in root tissues was confirmed.

Lymphocytes exposed to vegetables grown in waters contaminated by anticancer drugs: metabolome alterations and genotoxic risks for human health

Wastewater irrigation of crops may be effective to avoid depletion (about 70%) of freshwater resources. However, the use of reclaimed waters containing persistent microcontaminants such as antineoplastic drugs is of high environmental concern. These active compounds may affect human health with potentially severe adverse effects. To better understand the impact on human health following irrigation of crops with reused contaminated waters, we exposed four edible plants, Brassica rapa, Lactuca sativa, Raphanus sativus, and Triticum durum, to two commonly used antitumoral drugs: 5-fluorouracil (5-FU), and Cisplatin (CDDP), using metabolomics as a potential functional genomics tool to combine with genotoxicity experiments. The metabolome of the treated and untreated plants was analysed to detect biochemical alterations associated to the exposure, and the potential genotoxic damage related to human exposure to the treated plants was evaluated using the comet assay in human lymphocytes, which are characterized by high sensitivity to genotoxic substances. The edible species were able to assimilate 5-FU and CDDP during the treatment, affecting the biochemical pathways of these plants with subsequent metabolome modifications. These metabolic alterations differed according to the specific species used for the test. Furthermore, all vegetables treated with two concentrations of the selected drugs (10 and 100 μg/L) caused significant (p < 0.0001) genotoxic damage in the cells of the immune system at a higher level than in the lymphocytes directly exposed to single antineoplastic drugs.

Naturally occurring bisphenol F in plants used in traditional medicine

Bisphenol F (BPF, 4-[(4-hydroxyphenyl)methyl]phenol) is a bisphenol that is structurally similar to bisphenol A (BPA). In response to consumer concern towards BPA, industry has started to substitute BPA for BPF and other bisphenol analogues in the production of epoxy resins and coatings for various applications. In 2016, it was reported that commercially sold mustard contained naturally occurring BPF. Here, the existing literature was reviewed to investigate whether other natural sources of BPF among edible plants exist, including their impact on human exposure to BPF. Coeloglossum viride var. bracteatum (rhizome), Galeola faberi (rhizome), Gastrodia elata (rhizome), Xanthium strumarium (seeds) and Tropidia curculioides (root) were found to contain naturally occurring BPF. Botanical extracts from these plants are used in traditional Chinese medicine. The highest values of BPF were recorded for G. elata and T. curculioides. Information on precise doses of the plant extracts used is scarce; however, for G. elata, also known as Tian Ma and available in powder form, a daily exposure of BPF from this source could theoretically amount up to 4.5 µg/kg body weight per day (based on a 70 kg body weight). Therefore, herbal products used in traditional Chinese medicine should be considered as a potential source contributing to the overall human exposure when assessing endocrine-active bisphenolic compounds.

Terpene core in selected aromatic and edible plants: Natural health improving agents

Aromatic plants synthesize and produce aromatic molecules, among these compounds some of them belong to terpenes and terpenoids. Plant species have specific genes involved in secondary metabolism which allows them to synthesize various compounds with terpene core. These kinds of plant species are also known as herbal drugs and they are primarily used as components in medicinal products or simply as health foods. This chapter will focus on terpene and terpenoid compounds found in selected edible and aromatic plants belonging to several plant families. Selected plant species are briefly discussed. Biologically active compounds with terpene core are most frequently found in essential oils of the edible and aromatic species, as well as they are separately isolated and identified from the extracts. Health beneficial effects coming from terpene compounds found in edible and aromatic plants are further presented and include antimicrobial, antiviral, cytotoxic, anticancer, anti-inflammatory and many other pharmacological activities.

Food additives and bioactive substances from in vitro systems of edible plants from the Balkan peninsula

During the last few years there is an increasing demand to the natural biologically active compounds. According to the World Health Organization (WHO) about 11% of the conventional medicines are of plant origin. Nowadays, plant biotechnologies are modern and reliable tool for producing valuable bioactive compounds. Recently, the potential of plant cells as foods also was confirmed. The advantages of plant in vitro systems over the intact plants are well known: growing under controlled and optimized laboratory conditions; independence of climatic and soil differences; preservation of rare and endangered plant species; cultivation in diverse bioreactor systems for increasing production yields of target metabolites. There have been developed many in vitro systems for production of various plant bioactive compounds with potential application in food industries. But potential for industrial implementation of this technology depends on solving problems with the scale-up of bioreactor cultivation, development of additional approaches for improving/modification of bioactivities of the target plant secondary metabolites, and to find way to exclude or replace in the culture media the carcinogenic plant growth regulator 2,4-dichlorophenoxyacetic acid (2,4-D) with its safety analogs, such as α-naphtaleneacetic acid (NAA) and/or indole-3-butyric acid (IBA). The aim of the current mini review is to summarize information about different in vitro systems of edible plants from the Balkan Peninsula with potential for producing food additives and biologically active substances and to describe prospects for successful industrial implementation of this technology.

Heavy metal content of edible plants collected close to an area of intense mining activity (southern Portugal)

The Neves-Corvo mining complex (MC) situated in southern Portugal exploits one of the most world's important copper deposits. Agricultural soils surrounding the MC, used by the inhabitants for crop production, contain excessive amounts of As, Cu, Pb, and Zn. Thus, a potential risk to human consumption exists if edible plants grow on these substrata. Arsenic and Pb were not detected in edible samples collected near the MC and 5 km away, but in the leaves-structural or adsorbed onto the surface. In general, Zn was the most mobile element in both contaminated and reference areas as seen by the bioaccumulation factors (BAF). The tolerable upper intake (TUI) values for Cu are a reason of concern, since in 57.1% of the cases, the TUI values are above the recommended upper limit of 5 mg/day, in the case of Ficus carica, Cucurbita pepo, and Phaseolus vulgaris, whereas in 28.6% of the cases, the TUI values are near this limit (C. pepo and Citrus x sinensis). The consumption of such vegetables from these areas must be banned or strongly reduced, since long-term accumulation of Cu can cause a chronic toxicity in humans.

The problem of misidentification between edible and poisonous wild plants: Reports from the Mediterranean area

Today, in many European countries, people are looking for wild edible plants to experience new tastes and flavors, by following the new trend of being green and environmentally friendly. Young borage and spinach leaves can be easily confused by inexpert pickers with those of other plants, including poisonous ones, such as Mandragora autumnalis Bertol. (mandrake) or Digitalis purpurea L. (foxglove), common in southern and northern Italy respectively. In the last twenty years, several cases of intoxication by accidental ingestion of mandrake and foxglove have been reported. The purpose of this work was to perform a pharmacognostic characterization of young leaves from borage, mandrake, foxglove and spinach, by micro-morphological, molecular and phytochemical techniques. The results showed that each of the three techniques investigated could be sufficient alone to provide useful information for the identification of poisonous species helping the medical staff to manage quickly the poisoned patients. However, the multi-disciplinary approach proposed could be very useful to asses the presence of poisonous plants in complex matrices, to build a database containing morphological, molecular and phytochemical data for the identification of poisonous species or in forensic toxicology, given their increasingly frequent use due to their low cost and relatively common availability.

An ethnobotanical survey of medicinal and edible plants of Yalo Woreda in Afar regional state, Ethiopia

BACKGROUND

The Afar people inhabit the sub-arid and arid part of Ethiopia. Recurrent drought and invasive encroaching plants are taking out plants that have cultural importance, and threaten the biodiversity and the associated traditional knowledge. Thus, the aim of the current study is to conduct an ethnobotanical survey and document medicinal and edible plants in Yalo Woreda in Afar regional state.

METHODS

A cross-sectional ethnobotanical study was carried out in eight kebeles of Yalo Woreda from October 2015 to December 2016. One hundred sixty informants were selected using purposive sampling. The data on diseases, medicinal and edible plants were collected using semi-structure interview and group discussion. The statistical methods, informant consensus factor, fidelity level, and preference ranking were conducted to analyze the data.

RESULTS

One hundred and six plants were reported; gender and age differences had implication on the number of plants reported by informants. The knowledge of medicinal plants among informants of each kebele was not different (p < 0.5) and was not associated in particular with the religious establishment in the kebeles (informant*kebeles, Eta square = 0.19). Family Fabaceae was the major plant species, and shrubs (44%) were dominant plants reported. Leaf (52.94%) and oral (68%) were primary plant part used for remedy preparation and route of application, respectively. The plants with low fidelity values Indigofera articulata (0.25), Cadaba farinosa (0.22), Cadaba rotundifolia (0.19), and Acalypha fruticosa (0.15) were used to treat the category of diseases with high informant consensus value (0.69). Sixteen edible plants were identified that were consumed during wet and dry seasons. Balanites aegyptiaca, Balanites rotundifolia, and Dobera glabra were 'famine food' that were collected and stored for years.

CONCLUSION

People in Yalo Woreda are more dependent on natural resources of the area for their livelihood. The threat of climatic change and encroaching invasive plants on medicinal and edible plants affects the traditional use of plants in the Yalo Woreda. The conservation of the plants in the home garden and natural habitat and integration of edible plants into agroforestry development programs in sub-arid and arid regions has to be encouraged to conserve plants of medical and economic importance.

Isolation, biological evaluation and validated HPTLC-quantification of the marker constituent of the edible Saudi plant Sisymbrium irio L

Phytochemical investigation and chromatographic purification of the n-hexane fraction of the aerial parts of the edible Saudi plant Sisymbrium irio led to the isolation of β-sitosterol (1), stigmasterol (2) and β-sitosterol-β-d-glucoside (3). The cytotoxic effects of the n-hexane, dichloromethane, ethyl acetate and n-butanol fractions were tested against three cancer cell lines viz., MCF-7, HCT-116 and HepG2, using the crystal violet staining (CVS) method, while the antibacterial activity against a number of pathogenic bacterial strains, was also estimated using the broth microdilution assay. The n-hexane fraction showed potent cytotoxic activities against all tested human cancer cell lines (IC₅₀: 11.7–13.4 μg/mL), while the dichloromethane fraction was particularly potent against HCT-116 cells (IC₅₀: 5.42 μg/mL). On the other hand, the n-hexane and EtOAc fractions demonstrated significant inhibitory activities against the Gram positive bacteria S. pyogenes and C. perfringens; and the Gram negative bacterium S. enteritidis. Our results warrant the therapeutic potential of S. irio as nutritional supplement to reduce the risk of contemporary diseases. Additionally, a validated high performance thin-layer chromatography (HPTLC) method was developed for the quantitative analysis of biomarker β-sitosterol glucoside (isolated in high quantity) from the n-hexane fraction. The system was found to furnish a compact, sharp, symmetrical and high resolution band for β-sitosterol glucoside (R_f = 0.43 ± 0.002). The limit of detection (LOD) and limit of quantification (LOQ) for β-sitosterol glucoside was found to be 21.84 and 66.18 ng band⁻¹, respectively. β-sitosterol glucoside was found to be present only in n-hexane fraction (2.10 μg/mg of dried fraction) while it was absent in the other fractions of S. irio which validated the high cytotoxic and antibacterial activity of n-hexane fraction of S. irio.

Exposure studies of core-shell Fe/Fe(3)O(4) and Cu/CuO NPs to lettuce (Lactuca sativa) plants: Are they a potential physiological and nutritional hazard?

Iron and copper nanomaterials are widely used in environmental remediation and agriculture. However, their effects on physiological parameters and nutritional quality of terrestrial plants such as lettuce (Lactuca sativa) are still unknown. In this research, 18-day-old hydroponically grown lettuce seedlings were treated for 15 days with core-shell nanoscale materials (Fe/Fe(3)O(4), Cu/CuO) at 10 and 20mg/L, and FeSO(4)·7H(2)O and CuSO(4)·5H(2)O at 10mg/L. At harvest, Fe, Cu, micro and macronutrients were determined by ICP-OES. Also, we evaluated chlorophyll content, plant growth, and catalase (CAT) and ascorbate peroxidase (APX) activities. Our results showed that iron ions/NPs did not affect the physiological parameters with respect to water control. Conversely, Cu ions/NPs reduced water content, root length, and dry biomass of the lettuce plants. ICP-OES results showed that nano-Cu/CuO treatments produced significant accumulation of Cu in roots compared to the CuSO(4)·5H(2)O treatment. In roots, all Cu treatments increased CAT activity but decreased APX activity. In addition, relative to the control, nano-Cu/CuO altered the nutritional quality of lettuce, since the treated plants had significantly more Cu, Al and S but less Mn, P, Ca, and Mg.

Field study on the accumulation of trace elements by vegetables produced in the vicinity of abandoned pyrite mines

To evaluate the accumulation of trace elements (TE) by vegetables produced in the vicinity of abandoned pyrite mines, eighteen different small farms were selected near three mines from the Portuguese sector of the Iberian Pyrite Belt (São Domingos, Aljustrel and Lousal). Total and bioavailable As, Cu, Pb, and Zn concentrations were analyzed in the soils, and the same TE were analyzed in three different vegetables, lettuce (Lactuca sativa), coriander (Coriandrum sativum), and cabbage (Brassica oleracea), collected at the same locations. The soils were contaminated with As, Cu, Pb, and Zn, since their total concentrations exceeded the considered soil quality guideline values for plant production in the majority of the sampling sites. The maximum total concentrations for those TE were extremely high in some of the sampling sites (e.g. 1,851 mg As kg(-1) in São Domingos, 1,126 mg Cu kg(-1) in Aljustrel, 4,946 mg Pb kg(-1) in São Domingos, and 1,224 mg Zn kg(-1) in Aljustrel). However, the soils were mainly circumneutral, a factor that contributes to their low bioavailable fractions. As a result, generally, the plants contained levels of these elements characteristic of uncontaminated plants, and accumulation factors for all elements <1, typical of excluder plants. Furthermore, the estimated daily intake (EDI) for Cu and Zn, through the consumption of these vegetables, falls below the recommended upper limit for daily intake of these elements. The sampling site that stood out from the others was located at São João de Negrilhos (Aljustrel), where bioavailable Zn levels were higher, a consequence of the slight acidity of the soil. Therefore, the Zn content in vegetables was also higher, characteristic of contaminated plants, emphasizing the risk of Zn entering the human food chain via the consumption of crops produced on those soils.

Study of selenocompounds from selenium-enriched culture of edible sprouts

Selenium is recognised as an essential micronutrient for humans and animals. One of the main sources of selenocompounds in the human diet is vegetables. Therefore, this study deals with the Se species present in different edible sprouts grown in Se-enriched media. We grew alfalfa, lentil and soy in a hydroponic system amended with soluble salts, containing the same proportion of Se, in the form of Se(VI) and Se(IV). Total Se in the sprouts was determined by acidic digestion in a microwave system and by ICP/MS. Se speciation was carried out by enzymatic extraction (Protease XIV) and measured by LC-ICP/MS. The study shows that the Se content of plants depends on the content in the growth culture, and that part of the inorganic Se was biotransformed mainly into SeMet. These results contribute to our understanding of the uptake of inorganic Se and its biotransformation by edible plants.