Toxic Effects Of Heavy Metals Research Articles

Enhancing the Phytoremediation of Heavy Metals by Plant Growth Promoting Rhizobacteria (PGPR) Consortium: A Narrative Review.

Heavy metal pollution has become a significant concern as the world continues to industrialize, urbanize, and modernize. Heavy metal pollutants impede the growth and metabolism of plants. The bioaccumulation of heavy metals in plants may create chlorophyll antagonism, oxidative stress, underdeveloped plant growth, and reduced photosynthetic system. Finding practical solutions to protect the environment and plants from the toxic effects of heavy metals is essential for long-term sustainable development. The direct use of suitable living plants for eliminating and degrading metal pollutants from ecosystems is known as phytoremediation. Phytoremediation is a novel and promising way to remove toxic heavy metals. Plant growth-promoting rhizobacteria (PGPR) can colonize plant roots and help promote their growth. Numerous variables, such as plant biomass yield, resistance to metal toxicity, and heavy metal solubility in the soil, affect the rate of phytoremediation. Phytoremediation using the PGPR consortium can speed up the process and increase the rate of heavy metal detoxification. The PGPR consortium has significantly increased the biological accumulation of various nutrients and heavy metals. This review sheds light on the mechanisms that allow plants to uptake and sequester toxic heavy metals to improve soil detoxification. The present review aids the understanding of eco-physiological mechanisms that drive plant-microbe interactions in the heavy metal-stressed environment.

Toxic Effect of Heavy Metal Poisoning on Living Organisms in Water and Health Risk: A Central India Study

The main causes of this environmental catastrophe are pollutants such as iron, zinc, lead, nickel, and chromium that have entered the water system as a result of uncontrolled industrial effluent discharge in the area. This study finds resistant bacteria and shows the toxicity of heavy metals in industrial effluent near the steel industry. Five separate locations were used for water sampling, and 16s RNA sequencing of the microorganisms that were found was done along with physicochemical parameter analysis and atomic absorption spectrophotometer use. Different water samples’ conductivity, TDS, salinity, DO, turbidity, and pH levels indicate changes in the quality of the water. In addition to having higher values for each of these characteristics, Sample D3’s water samples had greater concentrations of heavy metals, suggesting contamination. Aspergillus niger and Aspergillus terreus were identified in all samples. Both Gram-negative and Gram-positive Bacilli’s resistance to heavy metals has been found to be a sign of microbial adaptation to exposure to heavy metals. 16s rRNA sequencing of microorganisms revealed their roles in heavy metal bioremediation processes. The delicate balance between the flora and fauna in the affected water bodies has been upset by the devastating losses in aquatic life. In this study, we presented the biological methods for eliminating heavy metals, which comprised both metabolically dependent and independent techniques.

Edukasi Pemanfaatan Minyak Jelantah Dan Daun Kelor Menjadi Sabun Batang Sebagai Upaya Pencegahan Paparan Logam Berat Dari Pewarna Sintetis Dan Pestisida di Desa Tlingsing, Cawas, Klaten

Oxidative stress induced in cells by the generation of reactive oxygen species (ROS) is a toxic effect of heavy metals that exceed the threshold if they enter the body and can cause health threats. Apart from heavy metals that can cause oxidative stress are pesticides. The impact of oxidative stress will disrupt health because it has damaging properties on proteins, DNA and lipids. Exposure to heavy metals by workers and pesticides by farmers through skin contact, inhalation or respiration, to reduce the impact of inhalation or contact on the skin, in this service workers and farmers are given PHBS education, and one of them is by maintaining cleanliness after contact with colors or pesticides by means of wash your hands using soap. Community service is provided through counseling methods, health checks in the form of MCU, and making Moringa leaf soap which contains antioxidants

Potential Teratogenicity Effects of Metals on Avian Embryos

Agricultural areas can provide sources of food and hiding and nesting places for wild birds. Thus, the chemical load of potentially toxic elements (Cd, Cu, Pb) due to industrial and agricultural activities can affect not only the adult birds but also the embryos developing in the egg. The toxic effects of heavy metals applied alone were investigated on chicken embryos in the early and late stages of embryonic development using injection and immersion treatment methods. On day 3 of incubation, permanent preparations were made from the embryos to study the early development stage. There were no significant differences observed in embryo deaths and developmental abnormalities in this stage. On day 19 of incubation, the number of embryonic deaths, the body weight of the embryos, and the type of developmental abnormalities were examined. The embryonic mortality was statistically higher in the groups treated with cadmium and lead in the case of the injection treatment. A significant increase in developmental disorders was observed in the copper-treated group using the immersion application. The body weight significantly decreased in the cadmium- and lead-treated group using both treatment methods. However, a significant change in the body weight in the copper-treated group was only realized due to the injection method.

Response of Plant Endophyte Communities to Heavy Metal Stress and Plant Growth Promotion by the Endophyte Serratia marcescens (Strain JG1)

Effects of heavy metals on soil microbial communities have been extensively studied due to their persistence in the environment and imposed threats to living organisms; however, there is a lack of in-depth studies of the impacts of heavy metals on plant endophyte communities. Therefore, the responses of plant endophyte communities to different concentrations of heavy metals were investigated in this study. The endophyte communities of plants existing in severely (W1, Pb, 110.49 mg/kg, Cd, 1.11 mg/kg), moderately (W2, Pb, 55.06 mg/kg, Cd, 0.48 mg/kg), and mildly (W3, Pb, 39.06 mg/kg, Cd, 0.20 mg/kg) contaminated soils were analyzed by 16s rRNA high-throughput Illumina sequencing. Furthermore, networks were constructed to illustrate the relationships between microorganisms and environmental factors. High-quality sequences were clustered at a 97% similarity level. Results revealed that the diversity of the community and relative abundance of Cyanobacteria phylum increased with decreasing levels of pollution. Cyanobacteria and Proteobacteria were found to be the dominant phylum, while Methylobacterium and Sphingomonas were observed as the dominant genus. Tukey’s HSD test showed that the relative abundances of Cyanobacteria and Proteobacteria phyla and Methylobacterium and Sphingomonas genera differed significantly (p < 0.01) among the plants of the three sample sites. Environmental factor analysis revealed a significant negative correlation (p < 0.01) of Cyanobacteria and a significant positive correlation (p < 0.01) of Methylobacterium with the heavy metal content in the environment. These findings suggest that Cyanobacteria and Methylobacterium may be phylum and genus indicators, respectively, of heavy metal toxicity. Tax4Fun analysis showed the effect of heavy metal toxicity on the abundance of genes involved in plant metabolism. In addition, culturable endophytic strains were isolated to study their resistance to heavy metal stress and their ability to promote plant growth. The potting tests showed that the JG1 strain was tolerant to heavy metals, and it could significantly promote the growth of the host plant under stress caused by multiple heavy metals. Compared to the control, the JG1-treated plants showed a 23.14% increase in height and a 12.84% increase in biomass. Moreover, AP, AK, and HN contents in JG1-treated plants were 20.87%, 12.55%, and 9.03% higher, respectively, under heavy metal stress. The results of this study provide a scientific basis for the construction of an efficient plant endophyte restoration system.

Responses to exogenous elicitor treatment in lead-stressed Oryza sativa L.

Heavy metal toxicity adversely affects plants by changing physiological, biochemical, and molecular mechanisms. Lead (Pb) is one of the most common heavy metal pollutants. Hence this study investigated changes caused by exogenous methyl jasmonate (MeJA; 20 and 100 µM) and salicylic acid (SA; 2 and 20 mM) elicitors in local Karacadağ rice exposed to Pb stress (0, 100, and 400 ppm). The effects of elicitors on photosynthetic pigment content (chlorophyll a, chlorophyll b, and total carotenoid), proline, malondialdehyde (MDA), total phenolic and flavonoid, Pb, and total protein contents in stressed plants were evaluated. All parameters studied increased and decreased at varying rates in the treatment groups compared to the Pb-free group (control), indicating that rice plants were affected by Pb stress. The elicitors (MeJA, SA, and MeJA + SA) were applied by foliar spraying. The elicitor treatments increased photosynthetic pigment content, total protein, proline, total flavonoid, and phenolic contents depending on the elicitor type and concentration. MDA and Pb contents, increasing with Pb toxicity, decreased with elicitor treatments, and the stress degree was reduced. When the elicitors were compared, SA was more effective than MeJA in total flavonoid content at 400 ppm Pb toxicity. However, MeJA was more effective in photosynthetic pigment contents, MDA, total protein, Pb, total phenolic, and proline contents. The best results for all parameters examined in rice plants exposed to Pb toxicity were obtained from the 400 ppm Pb + 2 mM SA + 20 µM MeJA treatment group. In conclusion, this study showed that the combined application of MeJA + SA alleviated the harmful effects of Pb by reducing MDA and increasing photosynthetic pigments, total protein, proline, and secondary metabolites, especially at high Pb concentrations. Consequently, this study demonstrated that the combined use of MeJA and SA in rice plants eliminated the negative effects of stress quite effectively, even at high Pb concentrations. Therefore, future studies should focus on the synergistic application of different elicitors to better understand the effects of heavy metal toxicity on plant growth and development.

Spatial distribution, ecological and ecotoxicity evaluation of heavy metals in agricultural soils along Lala-Manjo Highway, Cameroon Volcanic Line

This study aims at assessing the spatial distribution, ecological and toxicity levels of heavy metals in agricultural soils of Lala-Manjo Highway in Cameroon. The soil samples were collected and analyzed by inductively coupled plasma-mass spectrometry. The result shows that Co, Cr, Cu, Hg, Mn, Ni, Sr, V and Zn concentrations are higher than those of the upper continental crust reference values except those of As, Cd and Pb. Correlation coefficient indicate similar input sources governed by same geochemical characteristics. Spatial distribution maps show high concentration of heavy metals in east, south and western part of the study area. Pollution indicators show that enrichment factor varied from moderate to high enrichment of heavy metals. The contamination degree (27.12–35.59), geo-accumulation index (0.01–4.94), and potential ecological risk index (RI = < 150) revealed a low to moderate levels of metallic pollution. The majority of stations have pollution load index and Nemerow integrated pollution index values greater than one, indicating serious pollution. Modified hazard quotient and toxic risk index suggest significant severity of pollution and low toxicity risk of heavy metals, pointing low toxicity effects of heavy metals to fauna and flora in the soil ecosystem. Considering the factors governing soils accumulation such as geology, climate and anthropogenic activities as well as the correlation with commonly used environmental background, it is proposed that the data from this study can be considered as a baseline of pollution to plan major agricultural developments in the area. The study underlines the importance of continuous monitoring and adaptive management for the preservation of soil ecosystem. The results may assist companies and local population in setting realistic targets for monitoring and remediation programs.

Synergistic role of phenylpropanoid biosynthesis and citrate cycle pathways in heavy metal detoxification through secretion of organic acids

Excessive heavy metal contaminants in soils have serious ecological and environmental impacts, and affect plant growth and crop yields. Phytoremediation is an environmentally friendly means of lowering heavy metal concentrations in soils. In this study, we analyzed phenotypic and physiological traits, and the transcriptome and metabolome, of sheepgrass (Leymus chinensis) exposed to cadmium (Cd), lead (Pb), or zinc (Zn). Phenotypic and physiological analysis indicated that sheepgrass had strong tolerance to Cd/Pb/Zn. Transcriptomic analysis revealed that phenylpropanoid biosynthesis and organic acid metabolism were enriched among differentially expressed genes, and metabolomic analysis indicated that the citrate cycle was enriched in response to Cd/Pb/Zn exposure. Genes encoding enzymes involved in the phenylpropanoid and citrate cycle pathways were up-regulated under the Cd/Pb/Zn treatments. Organic acids significantly reduced heavy metal accumulation and improved sheepgrass tolerance of heavy metals. The results suggest that synergistic interaction of the phenylpropanoid and citrate cycle pathways in sheepgrass roots induced organic acid secretion to alleviate heavy metal toxicity. A cascade of enzymes involved in the interacting pathways could be targeted in molecular design breeding to enhance phytoremediation.

Detoxification and removal of heavy metal by an acid-tolerant microalgae, Graesiella sp. MA1

Acidophilic/acid-resistant algae exhibit innate survival advantages in acid mine drainage (AMD), but their response remains poorly understood. In this study, the detoxification and removal of Graesiella sp. MA1 isolated from AMD to the heavy metals of Cu2+ and Mn2+ at pH 3.5 was evaluated. The physiological response mechanism of the algae to these two heavy metals was analyzed by measuring the changes of algal biomass, photosynthetic pigments, malondialdehyde (MDA), reduced glutathione (GSH) and sulfhydryl (-SH) contents, as well as the specific activities of superoxide dismutase (SOD) and ascorbate peroxidase (APX). The main functional groups bound to heavy metals in microalgae were analyzed using FITR and XPS spectra. Results indicate metal-induced growth and photosynthesis impacts, with MDA rising alongside metal concentrations. However, Graesiella sp. MA1 exhibited a certain degree of removal ability toward Cu2+ and Mn2+, and increased the pH of the medium from 3.5 to 5.12–5.73 and 9.07 (control group), indicating the potential ability to regulate the environmental pH. Additionally, this strain alleviated the toxic effects of heavy metals by regulating the level of SOD, APX, GSH, and -SH in the antioxidant system. FTIR and XPS analysis reveal that the functional groups, such as carboxyl, amide I and amide II, which related to proteins and polysaccharides on the microalgal surface, combined with Cu2+ and Mn2+ for extracellular removal. Clarifying the detoxification and removal process of heavy metals from acid-tolerant microalgae will help us to better use microalgae to repair AMD in situ.

Impact of Heavy Metal Contamination on Soil and Crop Ecosystem with Advanced Techniques to Mitigate Them

Heavy metal pollution in soils has become widespread globally due to both natural processes and human activities. Geologic and anthropogenic activities, such as mining, industrial processes, and agricultural practices, significantly contribute to heavy metal accumulation in soil, posing threats to both plant and animal health. These metals endure in the environment and build up in organisms because they resist breakdown or metabolism. They enter the food chain via primary producers and move up as higher trophic levels consume them. This contamination adversely affects the overall human health, plant growth, performance, and yield and also impacts the soil properties. To minimize this effect of heavy metal toxicity, bioremediation emerges as a highly effective method for treating such polluted soils, often conducted in situ, making it suitable for crop establishment or reestablishment. Bioremediation encompasses various techniques like bioventing, biostimulation, air sparging, natural attenuation, phytoremediation, vermistabilization, rhizofiltration, biosorption etc. Both microorganisms and plants play crucial roles in bioremediation, with the combined approach ensuring more efficient cleanup. However, the success of this method depends significantly on the specific species involved. Traditional physical and chemical remediation methods are often costly and fail to restore soil suitability for plant growth. In contrast, bioremediation offers a more environmentally friendly and economically viable solution, leveraging natural processes to encourage plant growth on contaminated soils.

Human health risk assessment and toxic effect of heavy metal(loid)s in Bamboo shoot products

Bamboo shoots and their products are an important part of the human diet. However, the accumulation and accurate human health risk of heavy metal(loid)s in bamboo shoots are largely unknown. In this study, we determined the total and bioaccessible concentrations of As, Cd, Pb, and Cr in natural and processed bamboo shoot products from markets in southwest China. The health risk assessment and enterotoxicity after consumption of heavy metal(loid)s contaminated samples were further studied using a human colonic epithelial cell (Caco-2 cell) model. The results showed that the average concentrations of As, Pb, Cd, and Cr in the collected samples were 0.036, 0.056, 0.008, and 0.049 mg/kg, while Pb contents in 21 collected fresh bamboo shoot samples exceeded the allowable limit value of 0.1 mg/kg by 1.00–4.60 folds. Besides, As in 2% fresh bamboo shoots exceeded the limit value of 0.50 mg/kg. The average bioaccessibility of heavy metal(loid)s in fresh bamboo shoots was as follows: Cr (47.20%) > Pb (39.56%) > Cd (15.64%)> As (13.29%). Estimated daily intake (EDI) of heavy metal(loid)s after intake of fresh bamboo shoots was higher in children than that in adults, the THQ of As is > 1 based on the total heavy metal(loid)s, indicating a potential non-carcinogenic risk for children. However, health risks assessment based on bioaccessibility were significantly decreased. Furthermore, intestinal digesta of high-risk samples did not trigger detrimental effects on Caco-2 cells, suggesting existing health risk assessment model may overestimate their health risks and should be adjusted by bioaccessibility and cellular toxicity validation to accurately reflect their health risk. Our data may provide a novel and scientific insight into the health risk assessment of bamboo shoots as well as their products and propose a more scientific approach to accurate health risk assessment for heavy metals polluted foods.

Phytohormones-mediated strategies for mitigation of heavy metals toxicity in plants focused on sustainable production.

In this manuscript, authors reviewed and explore the information on beneficial role of phytohormones to mitigate adverse effects of heavy metals toxicity in plants. Global farming systems are seriously threatened by heavy metals (HMs) toxicity, which can result in decreased crop yields, impaired food safety, and negative environmental effects. A rise in curiosity has been shown recently in creating sustainable methods to reduce HMs toxicity in plants and improve agricultural productivity. To accomplish this, phytohormones, which play a crucial role in controlling plant development and adaptations to stress, have emerged as intriguing possibilities. With a particular focus on environmentally friendly farming methods, the current review provides an overview of phytohormone-mediated strategies for reducing HMs toxicity in plants. Several physiological and biochemical activities, including metal uptake, translocation, detoxification, and stress tolerance, are mediated by phytohormones, such as melatonin, auxin, gibberellin, cytokinin, ethylene, abscisic acid, salicylic acid, and jasmonates. The current review offers thorough explanations of the ways in which phytohormones respond to HMs to help plants detoxify and strengthen their resilience to metal stress. It is crucial to explore the potential uses of phytohormones as long-term solutions for reducing the harmful effects of HMs in plants. These include accelerating phytoextraction, decreasing metal redistribution to edible plant portions, increasing plant tolerance to HMs by hormonal manipulation, and boosting metal sequestration in roots. These methods seek to increase plant resistance to HMs stress while supporting environmentally friendly agricultural output. In conclusion, phytohormones present potential ways to reduce the toxicity of HMs in plants, thus promoting sustainable agriculture.

Toxic effects of heavy metals on crustaceans and associated health risks in humans: a review

Toxic effects of heavy metals on crustaceans and associated health risks in humans: a review

Isoliquiritin counteracts cadmium-induced intestinal damage in mice through enhancing intestinal barrier function and inhibiting apoptosis

Cadmium (Cd), a crucial toxic environmental pollutant, can induce damage to many organs, especially the gastrointestinal tract. Isoliquiritin (ISO), a critical flavonoid glycoside compound isolated from Glycyrrhiza uralensis, has anti-inflammatory, anticancer, antioxidant and other pharmaceutical value. However, the potential roles of ISO in Cd-induced intestinal damage have not been reported yet. This study aimed to research the beneficial effects of ISO on Cd-induced intestinal damage and identify its underlying mechanisms. Our results showed that ISO reduced inflammation by suppressing the production of pro-inflammatory cytokines and the activity of serum Lipopolysaccharide (LPS) in mice with Cd exposure. In terms of mechanism, ISO administration protected the intestinal barrier function through increasing the expression of tight junction proteins and Muc2. Furthermore, ISO could significantly suppress Cd-induced intestinal apoptosis and activation of NLRP3 inflammasome. Interestingly, inhibiting the activation of NLRP3 by nigericin completely blocking the effect of ISO on apoptosis. Most importantly, ISO markedly abrogated Cd-induced cell damage and NLRP3 inflammasome activation in vitro. Taken together, these findings suggest that ISO reduces Cd-induced intestinal damage by increasing the goblet cells, improving intestinal barrier, suppressing NLRP3 inflammasome activation and inhibiting apoptosis, which may offer a novel strategy against the toxic effects of heavy metals.

Effects of heavy metal pollution on population dynamics of another important pollinator insect group: Horseflies (Diptera: Tabanidae)

Horseflies represent important agents of pollination as well as other pollinator insects, like butterflies, bees and wasps. Horseflies belong to the genera Atylotus, Dasyramphis, Glaucops, Pangonius, Philoliche, Chrysops, Hybomitra, and Tabanus species are exclusive nectar feeders. Glucose, fructose and sucrose are major components of plant nectars which are used nourishing for developing eggs. Because of these features horseflies have a significant role in pollination of phanerogams. This study was conducted to investigate the effects of toxic heavy metals on the population dynamics of horsefly species. Monthly changes on the accumulation of heavy metals in the larval habitats of horsefly species were determined with Perkin Elmer Optical Spectrophotometer and also correlations between concentrations of heavy metals and population fluctuations of horse fly species were observed. The results demonstrated that lead, iron and cadmium have statistically important negative effects on the population dynamics of horsefly species.

Spatial Distribution, Source Analysis, and Health Risk Assessment of Heavy Metals in the Farmland of Tangwang Village, Huainan City, China

The impacts of heavy metal pollution in arable soil on agricultural production, environmental health, and the wellbeing of urban and rural residents cannot be overlooked. It has become a significant bottleneck in achieving comprehensive rural revitalization. To accurately grasp the characteristics of heavy metal pollution in suburban cultivated soil, Tangwang Village (a suburb of Huainan City) was subjected to scrutiny. The contents of heavy metals (Hg, Cu, Hg, As, Pb, Cr, Cd, and Zn) in the topsoil of cultivated land in this area were detected, and their spatial distribution characteristics were analyzed using inverse distance spatial interpolation. (1) After conducting a comprehensive analysis and thorough examination of the PMF model sources, it was determined that Cu, Cd, and Zn exhibit a direct correlation with agricultural practices, collectively contributing to a cumulative percentage of 21.10%. Meanwhile, Cr is derived from a combination of sources, including both natural parent materials and human activities, accounting for a total proportion of 24.45%. Notably, lead emissions from automobile exhausts constitute a significant source, while arsenic is primarily associated with dispersed factories and their respective operations, contributing to respective proportions of 36.38% and 18.07%. It is evident that agricultural practices, transportation, and industrial activities are the main reasons for heavy metal pollution in arable soil. (2) The evaluation of geological accumulation indicators reveals that the level of soil arsenic accumulation pollution is mild to moderate (1.199). On the other hand, the cumulative pollution level of Cd, Hg, Cr, and Cu was relatively low (0.462→0.186), whereas the levels of Pb and Zn were below the threshold. (3) The assessment of the ecological risk index revealed that the predominant elements posing potential ecological risks in the investigated region were Hg, As, and Cd, with average Ei values of E(Hg) = 86.81, E(As) = 80.67, and E(Cd) = 67.83, respectively. (4) The human health risk assessment revealed significant differences in the single non-carcinogenic risk values of heavy metals generated by different exposure pathways, with oral ingestion &gt; dermal contact &gt; oral nasal inhalation. Children were more susceptible to the toxic effects of heavy metals compared to adults. Both As and Cr caused an increased risk of cancer in both children and adults, which is a matter of great concern. The results of this study contribute to a more accurate description of the sources of heavy metals in farmland soil. This study indicates that the application of PMF for soil source analysis yields clear results that can be further applied. This research also has potential policy significance as it can help to improve the sustainability of ecosystems by coordinating both environmental and human activities.

Metagenomic and biochemical analyses reveal the potential of silicon to alleviate arsenic toxicity in rice (Oryza sativa L.)

Arsenic (As) pollution in agricultural systems poses a serious threat to crop productivity and food safety. Silicon (Si) has been reported to mitigate toxic effects of heavy metals in plants. However, the mechanisms behind Si-mediated alleviation of As toxicity in rice (Oryza sativa L.) remain poorly understood. Here, we performed metagenomic and biochemical analyses to investigate the potential of Si in alleviating As toxicity to rice plants. As exposure reduced plant growth, chlorophyll contents, antioxidant enzyme levels and soil enzymes activity, while increasing reactive oxygen species (ROS) activity and inducing alterations in the rhizosphere microbiome of rice seedlings. Silicon amendments enhanced rice growth (24%), chlorophyll a (25%), and chlorophyll b (26.7%), indicating enhanced photosynthetic capacity. Si amendments also led to the upregulation of antioxidant enzymes viz., superoxide dismutase (15.4%), and peroxidase (15.6%), resulting in reduced ROS activity and oxidative stress compared to the As-treated control. Furthermore, Si treatment reduced uptake and translocation of As in rice plants, as evidenced by the analysis of elemental contents. Microscopic examination of leaf and root ultrastructure showed that Si mitigated As-induced cellular damage and maintained normal morphology. Metagenomic analysis of the rice rhizosphere microbiome revealed that Si application modulated composition and diversity of microbial communities e.g., Proteobacteria, Actinobacteria, and Firmicutes. Additionally, Si amendments upregulated the relative expression levels of OsGSH, OsPCs, OsNIP1;1 and OsNIP3;3 genes, while the expression levels of the OsLis1 and OsLis2 genes were significantly downregulated compared with As-treated rice plants. Overall, these findings contribute to our understanding of Si-mediated plant resilience to As stress and offer potential strategies for sustainable agriculture in As-contaminated regions.

Heavy Metal Levels in Males With Idiopathic Hypogonadotropic Hypogonadism.

The toxic effects of heavy metals on biological systems are being investigated with increasing interest day by day. Our purpose was to investigate heavy metals such as aluminum (Al), cadmium (Cd), arsenic (As), lead (Pb), and nickel (Ni) in males with idiopathic hypogonadotropic hypogonadism (IHH) and to determine whether there is a relationship between heavy metals and testosterone levels. Twenty-six male patients with IHH aged 18-50 and 22 healthy males aged 21-50 admitted to the Outpatient Department of Endocrinology for follow-up were enrolled.BMIs were calculated by measuring the height and weight of all participants. Al, Cd, As, Pb, and Ni levels were measured and compared between groups. Testosterone levels were measured to investigate whether there was a correlation with heavy metal levels. Al, Cd, As, Pb, and Ni levels were statistically higher in the patient group compared to the control group (p<0.001). A moderately strong significant negative correlation was detected between the patients' testosterone and As levels (p=0.001, r=-0.609, R2=0.371). Decreased As and Cd levels were observed as the patients' ages increased (p=0.013, r=-0.471). Heavy metals might play potential roles in IHH. We hope that investigating heavy metal levels in IHH and adding toxicity-preventive treatments to hormonal therapies will be beneficial in the multifaceted management of the disease in clinical practice.

Melatonin as an Ameliorative Agent Against Cadmium- and Lead-Induced Toxicity in Fish: an Overview.

Diverse anthropogenic activities and lack of knowledge on its consequences have promoted serious heavy metal contaminations in different aquatic systems throughout the globe. The non-biodegradable nature of most of these toxic heavy metals has increased the concern on their possible bioaccumulation in aquatic organisms as well as in other vertebrates. Among these aquatic species, fish are most sensitive to such contaminated water that not only decreases their chance of survivability in the nature but also increases the probability of biomagnifications of these heavy metals in higher order food chain. After entering the fish body, heavy metals induce detrimental changes in different vital organs by impairing multiple physiological and biochemical pathways that are essential for the species. Such alterations may include tissue damage, induction of oxidative stress, immune-suppression, endocrine disorders, uncontrolled cell proliferation, DNA damage, and even apoptosis. Although uncountable reports have explored the toxic effects of different heavy metals in diverse fish species, but surprisingly, only a few attempts have been made to ameliorate such toxic effects. Since, oxidative stress seems to be the underlying common factor in such heavy metal-induced toxicity, therefore, a potent and endogenous antioxidant with no side effect may be an appropriate therapeutic solution. Apart from summarizing the toxic effects of two important toxicants, i.e., cadmium and lead in fish, the novelty of the present treatise lies in its arguments in favor of using melatonin, an endogenous free radical scavenger and indirect antioxidant, in ameliorating the toxic effects of heavy metals in any fish species.

Determination of the Toxic Effects of Heavy Metals on the Morpho-Anatomical Responses of the Leaf of Typha latifolia as a Biomonitoring Tool.

Typha latifolia leaves act as sensitive barometers for trace heavy metal pollution, as revealed by their pronounced anatomical responses in a constructed wetland. Monthly water samples and Typha latifolia leaf tissue were collected over three consecutive months in 2018 from the Burgas Lake wetlands (Taoura), northeast Algeria. While physical and chemical parameters improved after treatment, atomic absorption spectrometry (Perkin Elmer A Analyst 800 AAS) detected persistent trace levels of cadmium, chromium, and lead in both the treated water and leaf tissue, highlighting the need for continued phytoremediation efforts. Microscopic examination of leaf tissue exposed to these metals revealed distinct anatomical adaptations, including shrunken vascular bundles, altered cell shapes, and stomatal closure. These findings underscore Typha latifolia's effectiveness in accumulating heavy metals and its potential as a highly sensitive biomonitor for persistent pollution in lake ecosystems.