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Urbanization and industrialization have led to heavy metals in aquatic environments. These metals are toxic, nondegradable, and persistent. Lead (Pb) is an immunotoxicant that can adversely affect animal health, even at low levels. Chitosan (CHI) is an eco-friendly compound with exceptional antibacterial and immunostimulant characteristics. This study investigated the effect of dietary CHI on the antioxidant defense system and innate immune responses of tilapia (Oreochromis niloticus) against the cytotoxic effect of prolonged Pb exposure. The results indicated dietary CHI could nullify the toxicity of prolonged Pb exposure in fish by substantially activating the antioxidant defense system capacity and fish innate immune responses. In addition, CHI minimized the alterations in the histology of fish organs. The findings suggest that chitosan can be a commercial, eco-friendly immunostimulant and bioactive compound for mitigating the effects of heavy metal toxicity in aquaculture.

The survival of organisms is threatened with a variety of pollutants and chemical compounds and population growth. Natural phenomena and human activities, especially industrial activities increase contamination of water, soil and air. Population growth leads to increased exploitation of the sea and oceans, thus the consumption of seafood increases. In addition, the main food of the people in some areas is fish. Consumption of fish has numerous benefits to healthy for humans, but the existence of some heavy metals including lead, cadmium, and etc. may cause toxicity to marine organisms. The degree of heavy metal toxicity depends on their chemical form of metals. Some forms of metals are rapidly excreted and do not have the opportunity to be absorbed and stored in body tissues, accordingly they are not very toxic, while some forms of metals are highly toxic and lethal. These forms are slowly excreted from metals and have the ability to be absorbed and accumulated in fish muscles and other organs. Heavy metals cause harmful effects such as carcinogenesis, malformations, damage to the nervous system, damage to the reproductive system and infertility in men, liver failure and cardiovascular disease and so on. Therefore, in this review focused on concentration of heavy metals in fish muscle is essential to ensure the safety of this type of food.

The PICT method (pollution-induced community tolerance) can be used to assess whether changes in soil microbial response are due to heavy metal toxicity or not. Microbial community tolerance baseline levels can, however, also change due to variations in soil physicochemical properties. Thirty soil samples (0–20 cm), with geochemical baseline concentrations (GBCs) of heavy metals and from five different parent materials (granite, limestone, schist, amphibolite, and serpentine), were used to estimate baseline levels of bacterial community tolerance to Cr, Ni, Pb, and Zn using the leucine incorporation method. General equations (n = 30) were determined by multiple linear regression using general soil properties and parent material as binary variables, explaining 38% of the variance in log IC50 (concentration that inhibits 50% of bacterial growth) values for Zn, with 36% for Pb, 44% for Cr, and 68% for Ni. The use of individual equations for each parent material increased the explained variance for all heavy metals, but the presence of a low number of samples (n = 6) lead to low robustness. Generally, clay content and dissolved organic C (DOC) were the main variables explaining bacterial community tolerance for the tested heavy metals. Our results suggest that these equations may permit applying the PICT method with Zn and Pb when there are no reference soils, while more data are needed before using this concept for Ni and Cr. This study has been funded by the Spanish Ministry of Economy and Competitiveness through the project CTM2015-73422-JIN (FEDER Funds). David Fernández-Calviño holds a Ramón y Cajal contract (RYC-2016–20411) fnanced by the Spanish Ministry of Economy, Industry and Competitiveness. Claudia CampilloCora holds a predoctoral fellowship fnanced by Xunta de Galicia (ED481A-2020/084). Diego Soto-Gómez was supported by a postdoctoral fellowship from the Spanish Ministry of Education “Juan de la Cierva Formación (FJC2019-039176-I).”

Plant biostimulants such as seaweed extracts, present a sustainable alternative to agrochemicals. Moreover, the accumulation of beach-cast seaweed (wrack), due to climate change and anthropic pressures, is expected to increase in the coming decades. Thus, from a perspective of circular economy, based on the valorisation of an organic residue, this study aimed at achieving an elemental and biochemical characterisation of beach wrack and understanding the effects of an aqueous extract prepared from this residue on the mitigation of metal-induced stress, using barley (Hordeum vulgare L.) as a model. The quantification of wrack’s macro- and micronutrients showed that K, Ca and Na were the most abundant elements, being this composition similar to that of other organic fertilisers. Furthermore, despite the studied wrack having lower values of photosynthetic pigments, amino acids and sugars, higher amounts of phenols and flavonoids (8.35 ± 0.24 and 3.95 ± 1.22 mg g−1 dry matter respectively) were detected when compared to freshly collected seaweeds. This work highlighted that wrack showed potential as a fertiliser—through increasing root biomass (63%) and leaf biometry (up to 45%) in plants treated with 5.0 and 7.5 g L−1 wrack extract alone—also being a possible cost-effective, eco-friendly and sustainable biostimulant to mitigate the phytotoxic effects of Cu, since plants treated with 7.5 g wrack L−1 showed an increase of 34% in leaf length, when compared to seedlings exposed only to Cu.

The concentrations of cadmium (Cd) and zinc (Zn) in arable lands exceed the maximum permissible levels due to the excessive use of phosphorus fertilizers and fungicides by farmers. The increasing issues related to the application of agrochemicals have lead to the demand for the implementation of sustainable agricultural approaches. Association of arbuscular mycorrhizae with crop plants is an appropriate strategy due to the potential of these microorganisms to augment the metals tolerance of plants through the immobilization of Cd and Zn in an eco-friendly manner. In the present study, 45 d old Zea mays (var. CoHM6) plants inoculated with AM fungi (Claroideoglomus claroideum) were exposed to 1.95 g Zn Kg−1 soil and 0.45 g Cd Kg−1 soil. The major objective of this study was to determine the metabolic alterations in the leaves and roots of mycorrhizal and non-mycorrhizal plants exposed to CdCl2 and ZnSO4. Both non AM and AM plants exhibited alterations in the quantity of primary and secondary metabolites on exposure to Zn and Cd toxicity. Moreover, Zn and Cd-induced accumulation of γ-sitosterol reduced the quantity of neophytadiene (a well-known terpenoid) and aided the production of 3-β-acetoxystigmasta-4,6,22-triene in maize leaves. Mycorrhization and heavy metal toxicity induced significant metabolic changes in the roots by producing 4,22-stigmastadiene-3-one, eicosane, 9,19-cyclolanost-24-en-3-ol, pentacosane, oxalic acid, heptadecyl hexyl ester, l-norvaline, and n-(2-methoxyethoxycarbonyl). In addition, the metal-induced variations in leaf and root lignin composition were characterized with the aid of the FTIR technique. Mycorrhization improved the tolerance of maize plants to Cd and Zn toxicity by stabilizing these metal ions in the soil and/or limiting their uptake into the plants, thus ensuring normal metabolic functions of their roots and shoots.

Soil amendment with biochar alleviates the toxic effects of heavy metals on microbial functions in single-metal contaminated soils. Yet, it is unclear how biochar application would improve microbial activity and enzymatic activity in soils co-polluted with toxic metals. The present research aimed at determining the response of microbial and biochemical attributes to addition of sugarcane bagasse biochar (SCB) in cadmium (Cd)-lead (Pb) co-contaminated soils. SCBs (400 and 600 °C) decreased the available concentrations of Cd and Pb, increased organic carbon (OC) and dissolved organic carbon (DOC) contents in soil. The decrease of metal availability was greater with 600 °C SCB than with 400 °C SCB, and metal immobilization was greater for Cd (16%) than for Pb (12%) in co-spiked soils amended with low-temperature SCB. Biochar application improved microbial activity and biomass, and enzymatic activity in the soils co-spiked with metals, but these positive impacts of SCB were less pronounced in the co-spiked soils than in the single-spiked soils. SCB decreased the adverse impacts of heavy metals on soil properties largely through the enhanced labile C for microbial assimilation and partly through the immobilization of metals. Redundancy analysis further confirmed that soil OC was overwhelmingly the dominant driver of changes in the properties and quality of contaminated soils amended with SCB. The promotion of soil microbial quality by the low-temperature SCB was greater than by high-temperature SCB, due to its higher labile C fraction. Our findings showed that SCB at lower temperatures could be applied to metal co-polluted soils to mitigate the combined effects of metal stresses on microbial and biochemical functions.

Bioavailable content of metals in aquatic systems has become critical in assessing the toxic effect of metals accumulating in the environment. Considering the need for rapid measurements, an optical microalgal-cyanobacterial array biosensor was developed using two strains of microalgae, Mesotaenium sp. and a strain of cyanobacteria Synechococcus sp. to detect Cd2+, Cr6+ and Zn2+ in aquatic systems. Microalgal and cyanobacterial cells were immobilized in a 96-well microplate using sol-gel method using silica. Optimum operational conditions for the biosensor array such as exposure time, storage stability, pH, and multiple metal effect were tested. A 10 min exposure time yielded optimum fluorescence values. Metal toxicity increased with decreasing pH, resulting in low relative fluorescence (%) and decreased with increasing pH, resulting in higher relative fluorescence (%). The optimum storage time for biosensor strains were 4 weeks for microalgal cultures and 8 weeks for cyanobacterial culture, at 4 °C storage temperature. The metal mixtures showed less effect on the inhibition of relative fluorescence (%) of microalgal/cyanobacterial cultures, displaying an antagonistic behavior among the metals tested. As a single unit, this photosynthetic array biosensor will be a valuable tool in detecting multi-metals in aquatic systems. HIGHLIGHTS A whole-cell microalgal-cyanobacterial array biosensor was successfully developed for monitoring acute metal toxicity in water systems.; Biosensor organisms respond to metals within 10 minutes' exposure.; Survival potential of the biosensor organisms was higher at high pH.; Antagonistic effect was shown by the biosensor organisms in metal mixtures.; Biosensor was viable throughout 8 weeks of storage at 4 °C.

Prediction of the behavior of heavy metals over time is important to evaluate the heavy metal toxicity in algae species. Various modeling studies have been well established, but there is a need for an improved model for predicting the chronic effects of metals on algae species to combine the metal kinetics and biological response of algal cells. In this study, a kinetic dynamics model was developed to predict the copper behavior (5 μg L-1, 10 μg L-1, and 15 μg L-1) for two freshwater algae (Pseudokirchneriella subcapitata and Chlorella vulgaris) in the chronic exposure experiments (8 d and 21 d). In the experimental observations, the rapid change in copper mass between the solutions, extracellular and intracellular sites occurred within initial exposure periods, and then it was slower although the algal density changed with time. Our model showed a good agreement with the measured copper mass in each part for all tested conditions with an elapsed time (R 2 for P. subcapitata: 0.928, R 2 for C. vulgaris: 0.943). This study provides a novel kinetic dynamics model that is compromised between practical simplicity and realistic complexity, and it can be used to investigate the chronic effects of heavy metals on the algal population.

Increased focus on the development and application of bioavailability-based metal water quality guideline values requires increased understanding of the influence of water chemistry on metal bioavailability and toxicity. Development of empirical models, such as multiple linear regression models, requires the assessment of the influence of individual water quality parameters as toxicity-modifying factors. The present study investigated the effect of pH on the lability and toxicity of zinc (Zn) to a tropical green microalga (Chlorella sp.). Zinc speciation and lability were explored using the Windermere Humic Aqueous Model (WHAM7), ultrafiltration, and diffusive gradients in thin films (DGT). Zinc toxicity increased significantly with increasing pH from 6.7 to 8.3, with 50% growth inhibition effect concentrations decreasing from 185 to 53 µg l-1 across the pH range. Linear relationships between DGT-labile Zn and dissolved Zn did not vary across the tested pH range, nor did the linear relationship between dissolved (

Sodium (Na) and arsenic (As) toxicity were monitored by hyperaccumulation of metals in Salvinia natans L. with 2,4-dichlorophenoxyacetic acid (2,4-D) induction. Salvinia was recorded with significant bioaccumulation of those metals with de-folding of cellular attributes in sustenance under toxic environment. 2,4-D priming has revised the growth components like net assimilation rate and relative water content to register initial plants' survival against Na and As. Proline biosynthesis supported in the maintenance of osmotic adjustment and plants sustained better activity through subdued electrolytic leakage. Oxidative stress due to both Na and As exposure is responsible for induction under significant moderation of lipid peroxidation and protein carbonization by 2,4-D application was evident to release the stress from metal and metalloids. Reactive oxygen species (ROS) like superoxide and hydrogen peroxide accumulation were monitored with activity of NADP(H)-oxidase. However, it was downregulated by 2,4-D to check the oxidative damages. Superoxide dismutase and peroxidases were significantly moderated to reduce the oxidative degradation for both metals with 2,4-D induction. Glutathione metabolism and recycling of ascorbate with monodehydroascorbate activity were other features to maintain the redox homeostasis for metal toxicity. At the molecular level, polymorphic variations of concern genes in redox cascades demarked significantly for those two metals and established the biomarker for those metals, respectively. As a whole, the biocompatibility of auxin herbicide in Salvinia may raise the possibility for auxin metabolism and thereby, the bioaccumulation to Na and As vis-à-vis tolerance for ecological safety is established.

Redox metabolism is integral to the functioning of photosynthetic organisms. The highly oxidative reactive oxygen species (ROS) are products of cellular redox processes and can cause major cellular...

Currently, producing safe agricultural commodities from the crop plants cultivated in the soil with increasing heavy metal toxicity is a gigantic challenge in front of researchers. Heavy metals are absorbed and translocated in the crop plants and then transferred to every downstream consumer of the food chain, including humans, causing serious disorders and ailments. The current research presents a combined schematic application of iron nanoparticles (Fe-NPs) and/or silicon (Si), to mitigate cadmium (Cd) stress in Lima bean (Phaseolus lunatus). It was noted that Cd-induced toxicity curtailed growth, antioxidative machinery, glyoxalase system and nutrient uptake of the plants. Furthermore, the physiochemical features of Cd stressed plants, including carotenoids, chlorophyll, photochemical quenching, photosynthetic efficiency, and leaf relative water contents, were improved by the combined application of Si and Fe-NPs. Moreover, higher levels of malondialdehyde (MDA), methylglyoxal (MG), hydrogen peroxide (H2O2), and electrolyte leakage (EL) were observed in Cd stressed plants. Nevertheless, the independent treatment or combined application of Si and/or Fe-NPs attenuated the adversative effects of Cd on the aforementioned growth attributes. Furthermore, Si and Fe-NPs defended plants from the injurious effects of MG by improving the activities of the glyoxalase enzyme. The Si and Fe-NPs reduced Cd contents but at the same time improved uptake and accumulation of nutrients in treated plants exposed to the Cd regime. This study highlights that Si and Fe-NPs have enormous potential to mitigate Cd-induced phytotoxicity by declining Cd uptake and improving the growth attributes of plants if applied in combination.

Abiotic stress has become an alarming issue for plant survival due to the constant changes in the environment. Abiotic stresses such as drought, salt, waterlogging, and heavy metals largely influence plant growth and development that finally reduce crop productivity. The present study was carried out to investigate the responses of jute (Corchorus olitorius cv. O-9897) plant under different abiotic stresses. At 15th days after sowing plants were exposed to different abiotic stresses for various duration. Two doses of NaCl (200 and 400 mM) were applied to impose salt stress, while two doses of CdCl2 (2 and 4 mM) were applied for cadmium (Cd) stress. Waterlogging stress was applied for 5 and 15 days. Whereas drought stress was imposed on plants for 10 and 15 days. Leaf relative water content, SPAD value, plant height, above ground fresh and dry weight, leaf area, and stem diameter decreased upon exposure to salt, water deficit, Cd, and waterlogging stresses. These abiotic stresses resulted in oxidative damage which was evident by the increased levels of lipid peroxidation, H2O2, and electrolyte leakage (EL) together with altered antioxidant enzymes activities and glyoxalase system which are crucial for plants to fight against oxidative damage. Both duration of waterlogging and drought stress drastically affected plant morphophysiology, whereas C. olitorius could tolerate moderate level of salt (200 mM NaCl) and Cd (2 mM CdCl2). So the present study reveals that abiotic stresses cause substantial damages to the morphophysiology and oxidative stress tolerance of C. olitorius where the higher doses of NaCl and CdCl2 as well as the increased duration of waterlogging and drought resulted in more deleterious effect.

Lead is one of the most dangerous pollutants to both the environment and humans. It causes structural changes in photosynthetic apparatus and reduced biosynthesis of chlorophyll pigments inhibits carbon metabolism. The aim of our study was to determine the dynamics of photosynthetic pigments in leaves of wheat (Triticum durum and T. aestivum), barley (Hordeum vulgare) and oats (Avena sativa) at different lead acetate, Pb(CH3COO)2 levels: 0, 0.15, 0.30 and 0.60 g/L. The results of this research indicate that these concentrations significantly affected chlorophyll content of H. vulgare and A. sativa as compared to T. durum and T. aestivum. Analysis of variance showed that lead concentration and interaction between cereal species had a significant effect on all chlorophyll characteristics at 0.1% probability and on carotenoids contents at 1% significance. Lead acetate in 0.3 and 0.6 g/L concentrations had a highly significant effect on chlorophyll a, b and carotenoids in H. vulgare seedlings, its carotenoid contents increased from 0.002 mg/g FW at 0 g/L to 0.107 mg/g FW at 0.6 g/L, whereas its chlorophyll content decreased under heavy metal stress, corresponding to the concentration of the metal ion. Carotenoids of A. sativa were not affected compared to Chl a and Chl b, while higher concentrations significantly increased chlorophyll contents of the seedlings from 1.384 mg/g FW of total chlorophyll at 0 g/L to 1.883 mg/g FW at 0.6 g/L. The increased amount of carotenoids was indicative of the formation of free radicals in plants under heavy metal stress, while decreased levels of chlorophyll content were an indication of reduction in the growth of the plants leading to decrease in the yield. It is suggested that chlorophyll content can be adopted as a very useful in vivo indicator of heavy metal toxicity.

Heavy metal toxicity and drought stresses are two growing concerns of the global population as these have a disastrous effect on the agriculture sector, creating oxidative stress in plants and leads to deleterious effects, which end up causing a major decline in yield. Hence, carving out the best candidate for combating both these stresses have become the prime objective of researchers. Plectranthus amboinicus (Lour.) Spreng., a medicinal plant, is regarded as one such candidate that can tolerate both drought and zinc stressors by the elicitation of metabolic changes. Variation in the composition of primary and secondary metabolites of P. amboinicus was evaluated in the leaf tissues of the plants subjected to drought and ZnSO4 (4 mM) treatments. Drought stress resulted in the accumulation of amino acids and sugars in the leaves of plants exposed to this stress. Similarly, zinc stress exhibited a remarkable impact on the synthesis of secondary metabolites like alkaloids, phenols, and flavonoids. Further, on carrying out GC–MS profiling, the compositional variation of secondary metabolites produced in P. amboinicus implicated its inherent potential to survive environments of these two stresses. Compounds like 2-methoxy-4-ethyl-6-methylphenol, gamma-sitosterol, hexadecanoic acid, alpha-amyrin, and ethyl linalool were some of the major secondary metabolites developed in leaves of plants under drought, whereas during ZnSO4 treatment, the major compounds developed were trans-alpha-bergamotene, squalene, 1,5-dimethyl-1-vinyl-4-hexenyl isovalerate, and spathulenol. This in turn makes the plant more compatible with the stressful environmental conditions, aiding it with better survival and protection. At the same time, the enhancement in the content of these metabolites in this medicinal plant under the influence of these stressors may have applications in the pharmaceutical industry, necessary for the development of novel drugs.

Increased accumulation of heavy metal ions such as Cr6+ and Co2+ due to release from prostheses and metallic implants has been reported. These metal ions have been shown to affect both resting and activated lymphocytes. Natural remedies towards mitigating the cytotoxic effects of metal ions are clearly warranted. Polyphenolic compounds which are part of hydrolysable tannins from natural plant sources are considered effective in cheating heavy metal ions in a biological system. We have isolated and characterized a polyphenolic compound (ellagic acid) from Terminalia arjuna fruits that has been tested for its ability to attenuate the metal ion toxicity in primary human lymphocytes in culture. Cr6+ and Co2+ (100 μM) decreased lymphocyte viability and proliferation and increased apoptosis of resting as well as CD3 and/or CD28-stimulated lymphocytes. Metal ions markedly diminished the cytokine (interleukin-2 and interferon-γ) secretion from activated lymphocytes. Pretreatment with ellagic acid at 25, 50, and 100 μM concentrations effectively improved viability and proliferative responses of both resting and activated lymphocytes, while attenuating the apoptotic index. Ellagic acid also tended to normalize the cytokine secretion from the activated lymphocytes even in the presence of metal ions, suggesting broad effects on the adaptive immune system.

Increasing industrial and anthropogenic activities are producing and releasing more and more pollutants in the environment. Among them, toxic metals are one of the major threats for human health and natural ecosystems. Because photosynthetic organisms play a critical role in primary productivity and pollution management, investigating their response to metal toxicity is of major interest. Here, the green microalga Chlamydomonas (Chlamydomonas reinhardtii) was subjected to short (3 d) or chronic (6 months) exposure to 50 µM cadmium (Cd), and the recovery from chronic exposure was also examined. An extensive phenotypic characterization and transcriptomic analysis showed that the impact of Cd on biomass production of short-term (ST) exposed cells was almost entirely abolished by long-term (LT) acclimation. The underlying mechanisms were initiated at ST and further amplified after LT exposure resulting in a reversible equilibrium allowing biomass production similar to control condition. This included modification of cell wall-related gene expression and biofilm-like structure formation, dynamics of metal ion uptake and homeostasis, photosynthesis efficiency recovery and Cd acclimation through metal homeostasis adjustment. The contribution of the identified coordination of phosphorus and iron homeostasis (partly) mediated by the main phosphorus homeostasis regulator, Phosphate Starvation Response 1, and a basic Helix-Loop-Helix transcription factor (Cre05.g241636) was further investigated. The study reveals the highly dynamic physiological plasticity enabling algal cell growth in an extreme environment.

Chemical pollution poses adverse effects on aquatic organisms, including altered gene expression. This study, therefore, investigated the hepatic expression of biomarkers of exposure and effect in Oreochromis niloticus inhabiting the drainage canal of a sugarbeet factory (an industrially polluted habitat) and the Nile River (a reference habitat). Compared to the Nile River, the drainage canal contained significantly elevated levels of heavy metals (Cd, Fe, Mn, Co, and Pb), nitrate, ammonia, nitrite, chemical oxygen demand, and biological oxygen demand. The liver of O. niloticus from the drainage canal accumulated significantly higher concentrations of the heavy metals. O. niloticus from the drainage canal had significantly higher hepatic expressions of genes related to oxidative stress (GSTa, GPx, and NRF2), metal toxicity (MT), endocrine disruption (Vtg), and hypoxia (HIF1a) and a significantly lower hepatic expression of the apoptosis-associated CAS gene. CYP1A (a detoxification biomarker) expression did not exhibit significant differences. These results provide insights into complex adaptive responses of O. niloticus to multiple chemicals and support the utilization of molecular biomarkers as warning signals for water pollution.

Background: Several heavy metals are found naturally in the earth crust and are exploited for various industrial and economic purposes. Among these heavy metals, a few have impact on the human body. Though some of these metals only have effect on human physiology in high doses, others such as cadmium, mercury, lead, chromium, silver, and arsenic have delirious effects in the body even in minute quantities, causing acute and chronic toxicities in human. Anxiety is a common psychiatric disorder among men and women. Occasional anxiety may be a normal a part of life. However, people with anxiety disorders frequently have intense, excessive and persistent worry and fear about everyday situations. Often, anxiety disorders involve repeated episodes of sudden feelings of intense anxiety and fear or terror that reach a peak within minutes (panic attacks). This study examined a major environmental risk factor of anxiety disorder and how the adverse impact of anxiety disorder could be ameliorated using zinc and vitamin E. Methods: Animals used for the researched were grouped into four. Group 1 represents control group; Group 2 represents animals exposed a heavy metal (CaCl2); Group 3 represents animals exposed to CaCl2 and then treated with zinc; and Group 4 represents animals exposed to CaCl2 and then treated vit E. Results: Results showed that exposure to heavy metals (CaCl2 in particular) causes severe anxiety disorders. Results also showed zinc and vit E have the capacity to ameliorate anxiety disorder caused by heavy metals. Conclusion: The human body should be adequately protected as man interacts with heavy metals to prevent anxiety disorder, and where a patient becomes a victim of the disorder, zinc and vit E could be used to manage the case.

Co-existence of toxic metals causes complex toxicity to microorganisms during bioremediation in water and soil. This study investigated the immobilization of Pb2+ and Cd2+ by fungus Aspergillus niger, which has been widely applied to environmental remediation. Five treatments were set, i.e., CK (no toxic metals), Pb2+ only, Cd2+ only, Pb2+/Cd2+ = 1:1(molar ratio), and Pb2+/Cd2+ = 2:1. Cadmium induced strong toxicity to the fungus, and maintained the high toxicity during incubation. However, as Pb/Cd ratio increased from 0 to 2, the removal rates of Cd2+ by A. niger were raised from 30 to 50%. The elevated activities of pyruvate dehydrogenase (PDH) and citrate synthetase (CS) enzymes confirmed that Pb addition could stimulate the growth of A. niger. For instance, citric acid concentrations and CS activities were 463.22 mg/L and 78.37 nmol/min/g, respectively, during 3-day incubation as Pb/Cd = 1. However, these two values were as low as ~ 50 with addition of only Cd. It was hence assumed that appropriate co-existence of Pb2+ enhanced microbial activity by promoting TCA cycle of the fungus. Moreover, the SEM analysis and geochemical modeling demonstrated that Pb2+ cations were more easily adsorbed and mineralized on A. niger with respect to Cd2+. Therefore, instead of intensifying metal toxicity, the addition of appropriate Pb actually weakened Cd toxicity to the fungus. This study sheds a bright future on application of A. niger to the remediation of polluted water with co-existence of Pb and Cd. • Cd2+ significantly inhibited P consumption, suggesting its high toxicity to A. niger. • Pb2+ stimulated the growth of A. niger by promoting TCA cycle in the cells. • Cd2+ removal by A. niger were improved with co-existence of Pb2+.

Heavy metals like cadmium and lead being very toxic have no precise, secure and efficient therapeutic administration of their toxicity. It is revealed in the scientific literature that several medicinal plants and natural products lower experimentally induced metal toxicity in animals. The present review attempts to assemble experimental data on the ameliorative effects of grape seed extract (GSE) and their derivatives against lead- and cadmium-induced toxicity. Several mechanisms are involved in GSE ameliorating the effect against cadmium and lead toxicity like antioxidant effect, reduction of apoptotic cells, prevention of DNA fragmentation, regulating the expression of pro-apoptotic protein level (Bax-α), increase in antiapoptotic protein (Bcl-2), and hindering apoptotic signaling.

Heavy metals are metal ions which acts as carcinogens and causes serious health issues as they produce free radicals and these free radicals cause damage to DNA which eventually leads to cancer. They are non-degradable in nature and responsible for contamination of various natural resources in environment mainly water contamination has become a major problem. Many metal ions such as cadmium, lead, arsenic, mercury are considered as toxic metals. The analysis of these metal ions is necessary and to detect these metal ions, several detection methods such as electrochemical biosensors, CNT’s, silver nanoparticles have been developed. In this paper, the toxicity and health effects of several heavy metals and their role in causing of oxidative stress have been summarized. Also, various heavy metal detection methods have been listed.

A review of nickel (Ni) toxicity to aquatic organisms was conducted to determine the primary water quality factors that affect Ni toxicity and to provide information for the development and testing of a biotic ligand model (BLM) for Ni. Acute and chronic data for 66 aquatic species were compiled for the present review. The present review found that dissolved organic carbon (DOC) and hardness act as toxicity-modifying factors (TMFs) because they reduced Ni toxicity to fish and aquatic invertebrates, and these effects were consistent in acute and chronic exposures. The effects of pH on Ni toxicity were inconsistent, and for most organisms there was either no effect of pH or, in some cases, a reduction in toxicity at low pH. There appears to be a unique pH effect on Ceriodaphnia dubia that results in increased toxicity at pHs above 8, but otherwise the effects of TMFs were consistent enough across all organisms and endpoints that a single set of parameters in the Ni BLM worked well with all acute and chronic toxicity data for fish, amphibians, aquatic invertebrates, and aquatic plants and algae. The unique effects of pH on C. dubia may be due to mixture toxicity involving both Ni and bicarbonate. The implications of this mixture effect on BLM modeling and a proposed set of BLM parameters for C. dubia are addressed in the review. Other than this exception, the Ni BLM with a single set of parameters could successfully predict toxicity to all acute and chronic data compiled in the present review. Environ Toxicol Chem 2021;40:2121-2134. © 2021 SETAC.

Heavy metal accumulation in crop grains due to hazardous metal contamination is considered a great concern. However, phytobeneficial fungi are reported to have important abilities for the biosafety of crops grown in contaminated soil. Therefore, the current study was undertaken to explore the mutualistic association of plant growth-promoting endophytic fungi in reducing heavy metal concentration in the seeds of soybean plants subsequently grown in contaminated soil, without comprising seed quality and biochemical profile. The results revealed that endophytic Paecilomyces formosus LHL10 and Penicillium funiculosum LHL06 synergistically produced higher amounts of GAs and IAA in a co-cultured medium. Moreover, the co-inoculation of LHL06 and LHL10 to soybean plants grown under multi-metal toxic conditions significantly mitigated the adverse effects of heavy metal toxicity and increased the seed production (number of pods per plants, number of seeds per pod, and 100 seed weight) of soybean plants grown under control and multi-metal toxic conditions. Moreover, the levels of carbohydrates (glucose, sucrose, and fructose), minerals (iron, calcium, magnesium, and potassium), amino acids (serine, glutamic acids, glycine, methionine, lysine, arginine, and proline), and antioxidants (superoxide dismutase, catalase, and peroxidase) were significantly enhanced in sole and co-inoculated plants under control and stress conditions. Whereas organic acids (citric acid, tartaric acid, malic acid, and succinic acid), lipid peroxidation (MDA) products, multi-metal accumulation (nickel, cadmium, copper, lead, chromium, and aluminum), and stress-responsive endogenous abscisic acid levels were significantly decreased in seeds of soybean plants grown under control and multi-metal toxic conditions upon LHL06 and LHL10 sole and co-inoculation. The current results suggested the positive biochemical regulation in seeds for improving the nutritional status and making it safe for human consumption.

Mangrove species are growing in exposed areas which have heavy metal contamination. The safeguard the mangrove ecosystem, it is important to understand their antioxidant responses to heavy metal toxicity. The goal of this study was to determine the effect of multi-heavy metals i.e. (Pb, Cd, Cr and Hg) on two mangrove plants Avicennia marina and Rhizophora mucronata of Indus delta via investigating their antioxidative defence mechanism of leaves and roots. In this regard mangrove seedlings of both species were treated with five different concentrations of four heavy metals and different time durations (15, 30, 45 and 60 days) for ascorbate peroxidase, catalase and superoxide dismutase in leaves and root tissues. The findings indicate that the heavy metals have significantly altered the antioxidant enzyme activities with respect of metals concentration and duration of exposure. With extended exposure higher antioxidant activities was observed in metal treated roots and leaves at higher concentrations. A pronounced stimulation (P

Heavy metal toxicity can either be acute or chronic effects. Long-term exposure of the body to heavy metal can progressively lead to muscular, physical and neurological degenerative process. In this research, a total of 30 representative chocolate samples were collected from local shops and markets in Lahore. All the samples were analysed to assess the levels of Lead (Pb), Nickel (Ni), Chromium (Cr) and Cadmium (Cd) by using Atomic Absorption Spectrophotometer in Pakistan Council of Scientific and Industrial Research (PCSIR), Lahore. It was observed that the majority of chocolate samples contain heavy metals levels higher than the permissible limits as recommended by Punjab Food Rules (PFR) 2011. The levels of Pb ranged between 0.375 and 3.4 mg/kg with 90% samples having concentrations exceeding PFR allowable limit (0.5 mg/kg). Whereas, Ni concentrations varied from 0.005 to 0.28 mg/kg and 80% samples were above the PFR limit (0.025 mg/kg). Further, Cr levels analysed between 0.005 to 0.28 mg/kg and 53% samples had Cr concentrations higher than PFR limit (0.02 mg/kg). Similarly, Cd levels were observed between 0.50-3.25 mg/kg with 53% samples having Cd concentrations exceeding the PFR limit (1.0 mg/kg). Investigation indicates that the quality of available chocolates is not recommendable for eating because of the higher concentrations of toxic heavy metals.

Ubiquitous presence of cyanobacteria even under extreme conditions since millions of years is due to their ease in adaptability to these environments through various cellular and molecular modifications. Formation of biofilms has been found to be one of the effective modes of survival under harsh environmental conditions, with exopolysaccharides (EPS) contributing to the formation of these biofilms. Cyanobacterial EPS are unique heteropolysaccharides and being anionic in nature, they have the capabilities for excellent heavy metal adsorption and thus, play a vital role in conferring tolerance against heavy metal toxicity. EPS biosynthesis occurs through multiple pathways involving a multitude of genes. A comprehensive overview on these genes in cyanobacteria using Nostoc sp. strain PCC7120 as the model organism has been discussed in this review. The review also emphasizes on the contribution of EPS to heavy metal remediation and biofilm formation. In the age of developing eco-friendly approaches for environmental clean-up, this information would help engineer cyanobacteria as a potential green technology tool for bioremediation and waste water management.

The potential for delayed mortality following short‐term episodic pollution events was evaluated by exposing cladocerans (Ceriodaphnia dubia) and rainbow trout (Oncorhynchus mykiss) to zinc (Zn) in various 1‐ to 48‐h and 1‐ to 96‐h exposures, respectively, followed by transferring the exposed organisms to clean water for up to 47 h for C. dubia and up to 95 h for trout for additional observation. For C. dubia, 1‐h exposures of up to 3790 µg Zn/L never resulted in mortality during the actual Zn exposures, but by 48 h, a 1‐h exposure to 114 µg/L, a concentration similar to the present US national water quality acute criterion for the test water conditions, ultimately killed 70% of C. dubia. With C. dubia, the speed of action of Zn toxicity was faster for intermediate concentrations than for the highest concentrations tested. For rainbow trout, pronounced delayed mortalities by 96 h only occurred following ≥8‐h exposures. For both species, ultimate mortalities from Zn exposures ≤8 h mostly presented as delayed mortalities, whereas for exposures ≥24 h, almost all ultimate mortalities presented during the actual exposure periods. With Zn, risks of delayed mortality following exposures to all concentrations tested were much greater for the more sensitive, small‐bodied invertebrate (C. dubia) than for the less sensitive, larger‐bodied fish (rainbow trout). These results, along with previous studies, show that delayed mortality is an important consideration in evaluating risks to aquatic organisms from brief, episodic exposures to some substances. Environ Toxicol Chem 2021;40:2484–2498. © 2021 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. This article has been contributed to by US Government employees and their work is in the public domain in the USA., Rainbow trout could withstand extreme Zn pulses of 1 to 3 h, with few subsequent deaths. Few Ceriodaphnia dubia died during 1‐ to 3‐h Zn pulses, but after 48 h, most were dead. Time to effects decreased as expected as rainbow trout were exposed to increasing Zn concentrations. Not so with C. dubia: time to effects was fastest in intermediate Zn exposures, with longer survivals in higher Zn exposures.

This study was conducted to evaluate the concentrations of heavy metals in the blood of birds reared for food in Camp2 Community of Akamkpa, Cross River State, Nigeria. Twelve (12) male indigenous jungle fowls (Gallus domestica), six each from the control site (Ugep) and from Camp2 were sampled for the studies. Venous blood samples from the wings of the blood were collected and used for hematological and metal analysis. After digestion of the blood, heavy metals [cadmium (Cd), Lead (Pb), Mercury (Hg), Chromium (Cr), Arsenic (As), and Nickel (Ni)] were detected using atomic absorption spectrophotometer (AAS). The results indicated that Cd, Pb, As and Hg) levels in birds from camp2 village was significantly higher (p0.05; p= 0.003) than that of the Ugep control site (4.22+1.07mg/L). The result shows that nickel, lead and Cadmium in blood samples were significantly (p

Bacillus licheniformis is a multi-metal tolerant bacteria, isolated from the paddy rhizospheric soil sample. Upon the multiple metal toxicity, B. licheniformis altered their phenotypic/morphogenesis. Here we examined the effects of cadmium (Cd2+), chromium (Cr2+), and mercury (Hg2+) on the morphogenesis of B. licheniformis in comparison to control. We found that the ability of bacteria to grow effectively in presence of cadmium and chromium comes at a cost of acquiring cell density-driven mobility and reformation of filamentous to donut shape respectively. In particular, when bacteria grown on mercury it showed the bacteriostatic strategy to resist mercury. Furthermore, the findings suggest a large variation in the production of exo-polysaccharides (EPS) and suggest the possible role of EPS in gaining resistance to cadmium and chromium. Together this study identifies previously unknown characteristics of B. licheniformis to participate in bioremediation and provides the first evidence on positive effects of bacterial morphogenesis and the involvement of EPS in bacteria to resisting metal toxicity.

1. Non-essential heavy metals such as mercury (Hg), arsenic (As), cadmium (Cd), and aluminium (Al) are useless to organisms and have shown extensive toxic effects. Previous studies show that two main molecular mechanisms of metal toxicity are oxidative stress and metal-metal interaction which can disrupt metal homeostasis.2. In this paper, we mainly illustrate metal toxicity and metal-metal interaction through examples in mammalians and D. melanogaster (fruit fly).3. We describe the interference of metal homeostasis by metal-metal interactions in three aspects including replacement, cellular transporter competition, and disruption of the regulation mechanism, and elaborate the mechanisms of metal toxicity to better deal with the challenges of heavy metal pollution and related health problems.

Although blackwaters, named for their rich content of dissolved organic carbon (DOC), are often very poor in ions and very acidic, they support great fish biodiversity. Indeed, about 8% of all freshwater fish species live in the blackwaters of the Rio Negro watershed in the Amazon basin. We review how native fish survive these harsh conditions that would kill most freshwater fish, with a particular focus on the role of DOC, a water quality parameter that has been relatively understudied. DOC, which is functionally defined by its ability to pass through a 0.45-µm filter, comprises a diverse range of compounds formed by the breakdown of organic matter and is quantified by its carbon component that is approximately 50% by mass. Adaptations of fish to acidic blackwaters include minimal acid-base disturbances associated with a unique, largely unknown, high-affinity Na+ uptake system that is resistant to inhibition by low pH in members of the Characiformes, and very tight regulation of Na+ efflux at low pH in the Cichliformes. Allochthonous (terrigenous) DOC, which predominates in blackwaters, consists of larger, more highly colored, reactive molecules than autochthonous DOC. The dissociation of protons from allochthonous components such as humic and fulvic acids is largely responsible for the acidity of these blackwaters, yet at the same time, these components may help protect organisms against the damaging effects of low water pH. DOC lowers the transepithelial potential (TEP), mitigates the inhibition of Na+ uptake and ammonia excretion, and protects against the elevation of diffusive Na+ loss in fish exposed to acidic waters. It also reduces the gill binding and toxicity of metals. At least in part, these actions reflect direct biological effects of DOC on the gills that are beneficial to ionoregulation. After chronic exposure to DOC, some of these protective effects persist even in the absence of DOC. Two characteristics of allochthonous DOC, the specific absorbance coefficient at 340 nm (determined optically) and the PBI (determined by titration), are indicative of both the biological effectiveness of DOC and the ability to protect against metal toxicity. Future research needs are highlighted, including a greater mechanistic understanding of the actions of DOCs on gill ionoregulatory function, morphology, TEP, and metal toxicity. These should be investigated in a wider range of native fish Orders that inhabit one of the world's greatest biodiversity hotspots for freshwater fishes.

Withania somnifera (L.) Dunal (Solanacea) is one of the well-known medicinal plants commonly called as Ashwagandha and also known as “Indian ginseng”. It contains Withanolides which are biologically active secondary metabolites, Anahygrine, Anaferine, sominiferine, sominiferinine, withanine and withananineare are also present in roots and leaves. Withania somnifera (L.) Dunal roots, leaves and preparations of the whole plants are traditionally used in Ayurveda and Unnani for various ailments. It is also having a high medicinal value and possesses potent anti-tumor and antioxidant properties. The present study deals with pot culture experiments with plants were grown in different treatments in black soil, Control (C): a control without any heavy metal treatment to the soil, Treatment No I: Cadmium 10ppm, Chromium 20ppm, Nickel 16ppm were introduced into the soil, Treatment No II: one % of Calcium hydroxide was also added along with heavy metals to soil. Then plants were grown up to the productivity levels. The heavy metal treated plants (Treatment No. I) showed lowest contents of soluble protein, non-reducing sugar, RNA, DNA, phenol, free proline, catalase and peroxides activity when compared to other treatments. The heavy metal treated plants (Treatment No. I) supported increase of total sugar, reducing sugar and polyphenol oxidase activity when compared to control plants and other treatment.

This study compares sulfate-reduction performance in an anaerobic sludge with different carbon sources (ethanol, acetate, and glucose). Also, the toxic effect of copper was evaluated to assess its feasibility for possible acid mine drainage (AMD) treatment. Serological bottles with 1.5 g VSS/L and 150 mL of basal medium (0.67 g COD/g SO42− at a 7–8 pH) were used to determine the percentage of electron equivalents, maximum specific methanogenic (SMA), and sulfide generation activities (SGA). The copper effect was evaluated in a previously activated sludge in batch bioassays containing different concentrations of copper (0–50 mg/L), 3 gVSS/L, and 150 mL of basal medium (0.67 g COD/g SO42−). Carbon source bioassays with glucose obtained the best results in terms of the SGA (1.73 ± 0.34 mg S2−/g VSS•d) and SMA (10.41 mg COD-CH4/g VSS•d). The electron flow in the presence of glucose also indicated that 21.29 ± 5.2% of the metabolic activity of the sludge was directed towards sulfidogenesis. Copper toxicity bioassays indicated that a considerable decline in metabolic activity occurs above 10 mg/L. The 20%IC, 50%IC, and 80%IC were 4.5, 14.94, and 35.31 mg Cu/L. Compared to the other carbon sources tested, glucose proved to be a suitable electron donor since it favors sulfidogenesis. Finally, copper concentrations above 15 mg/L inhibited metabolic activity in the toxicity bioassays. HIGHLIGHTS The influence of organic matter degradation and copper toxicity was assessed.; Potential application of sulfate reducing bacteria (SRB) for acid mine drainage treatment was evaluated.; The highest sulfidogenic activity was observed with glucose as carbon source.; High copper concentration impacts sulfate removal and sulfide production.

In ecotoxicology, in vitro testing on cell cultures represents an ideal alternative to in vivo strategies for emerging contaminants. These tests have limited use particularly with marine invertebrates like the clams Ruditapes decussatus. In the present study, a primary culture of R. decussatus haemocytes was realized for the first time in order to determine the effect of metals (copper, zinc, and cobalt) on haemocyte parameters like viability and phagocytosis. Results showed that (i) among the studied medium, the modified Leibovitz (L-15) is the best for R. decussatus haemocytes primary culture. (ii) The primary culture system used here represents a suitable in vitro model for assessing cytotoxic responses, (iii) a decrease of cell viability and phagocytosis after 24 h exposure to 100 μg mL-1 CoSO4 and an increase of phagocytosis after 24 h exposure to 50 μg mL-1CuSO4.

Incinerated biomedical waste ash (IBWA) contains an abundance of polyaromatic hydrocarbons (PAHs), heavy/toxic metals and, is highly alkaline in nature. To tackle the problems that could be caused ...

Heavy metals (HMs) and polycyclic aromatic hydrocarbons (PAHs) are persistent toxicants in coastal environments. Notably, in comparison to individual metal toxicity, knowledge about the effects of HMs and PAHs mixtures on kelps remains scarce. Accordingly, we performed in vitro experiments to determine the individual and combined effects of Cu, Cd, and PAHs on spore release, settlement, and germination on Macrocystis pyrifera and Lessonia spicata, two key-habitat forming kelp species of the coast of the Valparaiso Region in Chile. This region concentrates highly polluting industries, mainly due to unrestrained mining and fossil-fuel energy production. Single Cu, Cd, and PAHs treatments included concentrations in the ranges 5-200, 0.125-2000, and 0.05-100 μg/L, respectively, and a toxic-free treatment. Cu, Cd, and PAHs concentrations causing 20-50% (IC20, IC50) arrested spore release, settlement, and germination were determined, and the results shown in both species that single Cu, Cd, and PAHs IC20 values were generally lower on spore release than on spore settlement and germination, probably due to the absence of a cell wall in spores compared to later stages. Binary equitoxic IC20s mixture treatments changed from an antagonistic response to another with a greater inhibitory effect on spore release, from hour 1 to 7, whereas in IC50 treatments, the response was always antagonistic. The tertiary IC20 mixture of Cu+Cd+PAHs produced generally an antagonistic effect. Remarkably, all IC20 equitoxic mixture treatments showed a synergistic response on spore settlement in both kelps, suggesting that these toxicants are extremely harmful to kelp population persistence near highly polluted sites.

Aquaporins are important transmembrane channel proteins required for the transport of water and nutrients to maintain plant water relations and its survival. The aquaporins have a characteristic structure and are divided into 5 distinct isoforms such as plasma membrane intrinsic proteins (PIP), tonoplast intrinsic protein (TIP), small basic intrinsic protein (SIP), nodulin-26 like intrinsic protein (NIP) and X intrinsic proteins (XIP). Aquaporins conducts transcellular movement of water molecules across the cell and organelles membranes. Apart from playing key role in maintaining water level inside the plant system it is also involved in transporting small neutral molecules including glycerol, urea, metalloids, carbon dioxide, nitrogen, hydrogen peroxide and ammonia. In this way it regulates ionic homeostasis and water levels during environmental stresses including drought, chilling, salinity, and heavy metal toxicity and helps in providing tolerance toward the stress. It also plays a key role in maintaining the carbon and nitrogen level in the cell, transporting the key regulatory molecules and phytohormones mediated tolerance to plants. Scientist has also targeted aquaporins in order to develop stress tolerant transgenic species having improved functioning of aquaporins. Increase of water retention capability and usage efficiency by the plants represents the major research areas to confer abiotic stress tolerance. This review presents a comprehensive studies and intensive ongoing research to understand the diverse role of aquaporins in ensuring normal growth and development of plants. Current aspects of aquaporins and its isoforms in relation to its structure, function and regulation in different plant species have been highlighted. Further the potential of aquaporins in promoting plant survival during wide ranges of environmental situations is also emphasized.

This study investigated the effect of heavy metals on Labeo rohita inhabiting the Yamuna River, India. Levels of heavy metals measured in the water were as follows: Fe>Mn>Zn>Cu>Ni>Cr>Cd. Gill and liver tissue of exposed L. rohita showed a high metal pollution index, compared to reference fish collected from the Agra Canal. In the exposed fish, higher levels of creatinine and enzyme activity (alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase) were observed, while the A:G index declined. Additionally, higher TLC, lymphocytes, respiratory burst, and nitric oxide synthase activity indicated a heightened immune response. Levels of superoxide dismutase and lipid peroxidation were elevated, while catalase, glutathione S transferase, and glutathione was reduced. DNA of the exposed fish appeared deteriorated, with a greater mean tail length in comparison to the reference. Our results imply that Yamuna River water generates oxidative stress and DNA damage in L. rohita. As this river is a critical source of water and food to the native community, this could pose a threat to public health similar to that in the indicator organism.

Environment and food contamination with cadmium (Cd) can cause serious toxicity, posing a severe threat to agricultural production and human health. However, how amino acids contribute to defenses against oxidative stress caused by Cd in cells is not fully understood. As a model eukaryote with a relatively clear genetic background, Saccharomyces cerevisiae has been commonly used in Cd toxicity research. To gain insight into Cd toxicity and cell defenses against it, 20 amino acids were screened for protective roles against Cd stress in S. cerevisiae. The results showed that threonine (Thr, T) had the strongest protective effect against Cd-induced mortality and membrane damage in the cells. Compared to the antioxidant vitamin C (VC), Thr exhibited a higher efficacy in restoring the superoxide dismutase (SOD) activity that was inhibited by Cd but not by H2 O2 in vivo. Thr exhibited evident DPPH (2,2-diphenyl-1-picrylhydrazyl) activity but weak ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-9 sulfonic acid)) scavenging activity, giving it a weaker effect against Cd-induced lipid peroxidation and superoxide radical O2- , compared to VC. More importantly, compared to the chelating agent EDTA, Thr showed stronger chelation of Cd, giving it a stronger protective effect on SOD against Cd than VC in vitro. The results of the in vivo and in vitro experiments revealed that the role Thr plays in cell defenses against Cd may be attributed to its protection of the SOD enzyme, predominantly through the preferential chelation of Cd. Our results provide insights into the protective mechanisms of amino acid Thr that ameliorate Cd toxicity and suggest that a supplement of Thr might help to reduce Cd-induced oxidative damage.

Increased levels of trace metals are an important problem of environmental pollution. Ni is one of the metals essential for normal plant development, but elevated levels usually cause deleterious effects on plant growth. The aim of the study was to evaluate the effects sulphur nutrition on growth, oxidative status, and Ni bioaccumulation of Ni-treated rape (Brassica napus L.). Two different oilseed rape cultivars (Hammer and Compass) were grown under sulphur deficiency and under optimal S availability (0 and 1 mM sulphate, respectively) and exposed to 0.1, 0.3, and 0.5 mM Ni concentrations for 3 weeks. Exposure of plants to elevated Ni concentrations resulted in a decrease in the shoot and root biomass and chlorophyll content. The enhancement of Ni caused increased lipid peroxidation. The sulphur nutrition had an effect on the level of oxidative stress of Ni-treated plants-under the deficiency of sulphur the concentration of TBARS was significantly higher than under the optimal level of S. The beneficial effect of optimal sulphur nutrition was lower Ni accumulation in exposed plants but translocation of Ni was dependent on the cultivar.

Contamination of soils with heavy metals (HMs) caused serious problems because plants tend to absorb HMs from the soil. In view of HM hazards to plants as well as agro-ecosystems, we executed this study to assess metal toxicity to mung bean (Vigna radiata) plants cultivated in soil with six treatment levels of cadmium (Cd) and nickel (Ni) and to find metal tolerant variety, i.e., M-93 (V1) and M-1(V2) with multifarious plant biochemical and physiological attributes. Increasing doses of Cd and Ni inhibited plant growth and photosynthesis and both varieties showed highly significant differences in the morpho-physiological attributes. V2 showed sensitivity to Cd and Ni treatments alone or in combination. Tolerance indices for attributes presented a declined growth of Vigna plants under HM stress accompanied by highly significant suppression in gas exchange characteristics. Of single element applications, the adverse effects on mung bean were more pronounced in Cd treatments. V1 showed much reduction in photosynthesis attributes except sub-stomatal CO2 concentration in all treatments compared to V2. The yield attributes, i.e., seed yield/plant and 100-seed weight, were progressively reduced in T5 for both varieties. In combination, we have observed increased mobility of Cd and Ni in both varieties. The results showed that water use efficiency (WUE) generally increased in all the treatments for both varieties compared to control. V2 exhibited less soluble sugars and free amino acids compared to V1 in all the treatments. Similarly, we recorded an enhanced total free amino acid contents in both varieties among all the metal treatments against control plants. We conclude that combinatorial treatment proved much lethal for Vigna plants, but V1 performed better than V2 in counteracting the adverse effects of Cd and Ni.

The current study investigates the therapeutic and curative effect of Ulva lactuca polyphenolic extract (ULPE) in general and particularly polyphenolics compounds against heavy metal mixture (HME). The toxicity behind heavy metal is due to oxidative stress resulted from heavy metals pollution or administration through contaminated food (vegetables, water, and fish). Heavy metal toxicity plays a major role in different cardiovascular diseases. The objective of this study is aimed to examine the protective effect of ULPE against heavy metal mixture induced cardiovascular diseases through oxidative/antioxidant and inflammatory pathways. Sixty male rats (Sprague-Dawley) were assigned to six groups. Group I served as the control, group II served as the induced group receiving subcutaneously for 7 days 0.25 mg/100 gm body weight/day heavy metal mixtures (Equal concentration of Ni, Cd, Co and Hg chloride, and Pb acetate), group III received (i.p.) ULPE of dose 30 mg for 15 days, group IV served as the protected group pretreated with ULPE for 15 days as a protection dose, and then treated with the heavy metal-mixture, group V served as protected standard group pretreated with vitamin C (VitC ) (50 mg/Kg) and then treated with the heavy metal-mixture, and group VI served as standard group treated with VitC (50 mg/Kg). The main pathological changes within the heart revealed heart inflammation after heavy-metal mixtures administrations. On contrast to the protected group treated with ULPE (group IV), the protection group (group II) showed a significant increase in the antioxidant as well as anti-inflammatory biomarker. The cardiovascular biomarkers (Troponin T, CRP, and BNP) showed similar attitude elevations in induction group and decreased greatly in protection and VitC group. The antioxidant and the anti-inflammatory activities of ULPE are a consequence of their higher polyphenolic contents as well as marine secondary metabolites which are confirmed using qualitative and quantitative analysis. From the current result, we concluded that ULPE possesses a cardiovascular protective agent as a result of highly contents of different bioactive secondary metabolites which have antioxidant as well as free-radical scavenging and anti-inflammatory activates. Showed the mechanism of ULPE as cardioprotective against heavy metal mixture.

Smoking is one of the major causes of mortality and numerous diseases, both directly and indirectly. The role of smoking as a significant risk factor is already known in several human diseases such as cardiovascular diseases, lung cancer, and chronic obstructive pulmonary disease. We aimed to compare the toxicity of heavy metal levels in the two groups of cigarette smokers and non-smokers in Birjand during 2018. In this case-control study, 70 smokers were enrolled as the case group and 70 individuals with no history of smoking as control group. The cases were selected from among those who smoked 10 cigarettes per day without a drug use history. Heavy metal concentrations were collected in participants’ serum samples. Cluster analysis and principal components analysis were employed to compare heavy metal toxicity between the groups. The duration of smoking and the number of cigarettes consumed per day were 14.36 ± 12.75 years and 11.32 ± 7.23, respectively. The concentration of thallium (Ti), arsenic (As), manganese (Mn), and copper (Cu) was significantly higher in the smoker group than that in the non-smoker group (p