Hazardous Heavy Metals Research Articles

Assessment of proximate composition, mineral element profile and antioxidant properties of the edible oyster mushroom grown in Bangladesh

Mushrooms have been considered as a therapeutic and nutrient-rich foods in numerous countries for years due to their significant levels of nutritional components, vitamins and antioxidants. This study aimed to assess the nutrient content, mineral profile and antioxidant properties of eight different kinds of oyster mushrooms (Pleurotus sp.) cultivated in Bangladesh. The mushrooms were analyzed for their moisture content, carbohydrates, proteins, fats, fibers, ash, vitamin A, and vitamin C. The mineral profile included sodium, potassium, calcium, and iron, as well as heavy metals. Antioxidant activities were evaluated through various methods, including phenolic, flavonoid and tannin content, total antioxidant activity, and DPPH (2,2-diphenyl-1-picryl-hydrazyl) scavenging capacity. The findings revealed that the mushrooms under investigation were high in carbohydrate (ranges between 45.25 and 63.22 g/100 g), protein (23.48–33.16 g/100 g) and dietary fiber (42.87–52.31 g/100 g). The total ash content was ranged from 7.28 to 9.41 g/100 g and vitamin C content was 0.020–0.416 mg/100 g. Interestingly, all of the mushrooms had a lower fat content (0.91–2.6%). The mineral profile indicated the presence of varying concentrations of essential elements. Hazardous heavy metals, such as Cd and Cr were not detected in the mushroom sample, while As and Pb were detected but lower than the tolerance levels. The oyster mushrooms exhibited high levels of phenolic, flavonoid, and tannin contents, as well as significant antioxidant capacity. A methanol extract of the oyster mushrooms exhibited scavenging activity against DPPH in a dose dependent manner with the highest capacity (75.4%) obtained at a concentration of 0.2 mg/ml. Our result suggests that these studied oyster mushrooms could be a good source of nutrition and antioxidants, which could be used as functional foods.

Leveraging multi-omics tools to comprehend responses and tolerance mechanisms of heavy metals in crop plants.

Extreme anthropogenic activities and current farming techniques exacerbate the effects of water and soil impurity by hazardous heavy metals (HMs), severely reducing agricultural output and threatening food safety. In the upcoming years, plants that undergo exposure to HM might cause a considerable decline in the development as well as production. Hence, plants have developed sophisticated defensive systems to evade or withstand the harmful consequences of HM. These mechanisms comprise the uptake as well as storage of HMs in organelles, their immobilization via chemical formation by organic chelates, and their removal using many ion channels, transporters, signaling networks, and TFs, amid other approaches. Among various cutting-edge methodologies, omics, most notably genomics, transcriptomics, proteomics, metabolomics, miRNAomics, phenomics, and epigenomics have become game-changing approaches, revealing information about the genes, proteins, critical metabolites as well as microRNAs that govern HM responses and resistance systems. With the help of integrated omics approaches, we will be able to fully understand the molecular processes behind plant defense, enabling the development of more effective crop protection techniques in the face of climate change. Therefore, this review comprehensively presented omics advancements that will allow resilient and sustainable crop plants to flourish in areas contaminated with HMs.

Conversion of waste polystyrene into porous adsorbents for efficient removal of hazardous pollutants: Adsorption properties and adsorption mechanism

Herein, the porous adsorbent material (PS-SAS) was prepared by introducing a large number of carboxyl groups on the benzene ring of waste polystyrene (WPS) by Friedel-Crafts acylation reaction using succinic anhydride as the modifying group, followed by further alkaline modification, and was used for the removal of hazardous dye and heavy metal ion. The chemical structure and surface morphology of the prepared adsorbent were assessed via Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), optical microscope (OM), Brunauer–Emmett–Teller (BET), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The prepared adsorbent gave highly efficient separation performance towards malachite green (MG) and Cu2+ with corresponding maximum sorption capacities of 2231 mg/g and 156 mg/g at 298 K. The experimental data indicated that the sorption process followed the Langmuir adsorption isotherm and the pseudo-second-order kinetic model. Moreover, thermodynamic studies also demonstrated that the sorption process occurred spontaneously. The adsorption mechanisms of the adsorbent for MG include hydrogen bonding, electrostatic attraction, n-π interactions, and π-π interactions, while for Cu2+ via electrostatic attraction, ion exchange, and complexation. Furthermore, the selective adsorption, regeneration, dynamic sorption, and simulated wastewater experiment demonstrated that the adsorbent is a promising adsorbent. And phytotoxicity test proved that the prepared adsorbent can effectively reduce the toxicity of dye and metal ions. In summary, the transformation of waste polystyrene into an adsorbent represents a promising solution for water purification.

Ecotoxicological impacts of cadmium on soil microorganisms and earthworms Eisenia foetida: from gene regulation to physiological processes

Cadmium is a hazardous heavy metal that is commonly found in the soil and poses significant risks to soil organisms. The toxic effects of Cd on soil microorganisms and earthworms (Eisenia foetida) have been extensively studied, but most studies focused on high Cd pollution levels. Therefore, this study aims to investigate the different responses of soil organisms to moderate and low levels of Cd contamination. According to the study, the presence of 2.5 mg/kg of Cd had a significant impact on the microbial community’s composition and diversity. The relative abundance of most microbes decreased, while the abundance of Firmicutes and Actinobacteriota showed a considerable increase. The LEFSE analysis revealed that the Bacillus genus of the Firmicutes phylum can serve as a biomarker in soil contaminated with 2.5 mg/kg of Cd. At the same time, the functional analysis of PICRUSt 2 shows that microorganisms found in polluted soil have a noticeable decrease in their ability to metabolize lipids. On the other hand, our findings indicate that Cd has a detrimental effect on the biomass of earthworms and induces oxidative stress in these animals. The activation of superoxide dismutase (SOD) and catalase (CAT) enzymes in earthworms was carried out to mitigate oxidative stress. The study found a strong positive relationship between SOD and both time and Cd pollution. However, CAT exhibited inhibition throughout the later stages of the experiment, particularly when exposed to relatively higher levels of pollution. The analysis of RNA in earthworms revealed that soil Cd pollution at a concentration of 2.5 mg/kg primarily impacts the cellular structure and function of earthworms. This pollution disrupts the integrity of the cytoskeleton structure, hampers DNA replication, and compromises the precision of cell signaling. Simultaneously, when compared to the control group, several metabolic pathways exhibited abnormalities.

Effects of Laurus extract against cadmium-induced neurotoxicity in rats

Cadmium (Cd) is a hazardous heavy metal with widespread environmental presence, posing significant threats to human and animal health. This study investigates the neurotoxic effects of Cd exposure and explores the therapeutic efficacy of Laurus nobilis L. in counteracting these adverse effects. Cd exposure induces oxidative stress and neurotoxicity, leading to neuronal damage and histopathological alterations. Laurus, known for its antioxidant properties, is assessed for its potential in mitigating Cd-induced neurotoxicity through in vitro antioxidant assays, GC–MS analysis, HPLC profiling, and experimental animal models. Results demonstrate that Laurus ethanolic extract exhibits significant antioxidant activity, attributed to its phenolic and flavonoid constituents. GC–MS analysis reveals various bioactive compounds in the extract, including Hexadecanoic acid methyl ester and (Z)-13-Docosenamide, which posses neuroprotective properties. HPLC analysis identifies phenolic compounds such as ellagic acid and flavonoids like rutin and kaempferol in the extract. In vivo studies in rats exposed to Cd demonstrate that Laurus extract administration mitigates Cd-induced alterations in body and brain weight, hematological parameters, liver and kidney function, oxidative stress markers, and acetylcholinesterase (AchE) activity. Histopathological examination confirms the protective effects of Laurus against Cd-induced neuronal damage. The SOD model, validated with high resolution (2.05 Å) and strong R values (work: 0.192, free: 0.236, observed: 0.194), shows strong structural stability (C-score: 0.30). Docking studies reveal high binding affinities of kaempferol (−8.1 kcal/mol) and rutin (−8.7 kcal/mol) with SOD with kaempferol demonstrating superior solubility, lipophilicity, and drug-likenessSimulation analysis confirms the protein’s flexibility and adaptability, highlighting its therapeutic potential, especially with kaempferol. These findings suggest the therapeutic potential of Laurus. as a natural remedy for Cd-induced neurotoxicity, highlighting its antioxidant and neuroprotective properties.

Fluorescent cellulose hydrogels based on corn stalk of double sulfhydryl functional group modification for Hg(II) removal and detection

Ions of mercury, one of the most hazardous heavy metals in nature, pose serious risks to the environment and human health. Blue sulfur-doped carbon dots (SCDs) from corn stalks were utilized as material. The SCDs were incorporated into a carboxylated hydrogel modified with sulfur, and a compound gel (SCDs–KTOCS gel) was successfully fabricated for simultaneous fluorescence detection and Hg(II) adsorption. This enabled the effective identification and removal of Hg(II) from contaminated water. The chemical content, fluorescence properties, and adsorption behaviors of the SCDs–KTOCS–gels were analyzed. The results demonstrate that the SCDs–KTOCS–gels exhibited effective Hg(II) adsorption (193 mg/g) and an extensive linear spectrum for Hg(II) fluorescence emission (150–500 mg/L; detection limit = 1.5668 mg/L). The adsorption values fit well with the Temkin models and pseudo-second-order kinetics. Additionally, Hg(II) detection and adsorption in the SCDs–KTOCS–gels were examined. By exchanging the existing probe for a suitable one that fits various relevant applications, this study suggests an environmentally friendly and sustainable method of producing materials for removing and detecting Hg(II) and constructing a fluorescence hydrogel for the detection and adsorption of different metals.

Assessment of mechanical and heavy metal leaching behavior of engineered cementitious composites incorporating ultra-high-volume municipal waste incineration bottom ash

This study aimed to explore the feasibility of incorporating 100% municipal solid waste incineration bottom ash (MSWIBA) as a replacement for fine aggregates in engineered cementitious composites (ECCs). To improve mechanical properties, three types of polymer fibers (PVA, PP, and PE) were used at dosages of 0-2% by volume. The impact of fiber content on compressive strength, elastic modulus, and other key performance indicators such as peak strain, ultimate strain, damage modulus, and toughness index was systematically investigated. Results showed that while the elastic modulus and peak stress slightly decreased with increasing fiber content due to fiber agglomeration and increased macro-porosity, fibers significantly enhanced the deformation capacity and toughness. For instance, the MSWIBA-ECCs with 2% PP fibers exhibited the highest compressive damage energy of 205.47 J, a 79.48% increase over the control group, demonstrating superior toughness. Additionally, the study developed a new constitutive model that accurately predicted stress-strain behavior considering fiber characteristics. Environmental assessment revealed that MSWIBA-ECCs effectively immobilized hazardous heavy metals (Cu, Ni, Pb, Zn), with a solidification efficiency of 97%, ensuring compliance with Chinese environmental standards. These findings suggest that MSWIBA-ECCs, combined with optimized fiber content, offer a sustainable and high-performance alternative for construction applications.

The transcription factor OsNAC5 regulates cadmium accumulation in rice

Cadmium (Cd) is a hazardous heavy metal that threatens human health through the consumption of contaminated rice. To mitigate Cd accumulation in rice grains, it is crucial to reduce Cd uptake. Nevertheless, the transcriptional mechanisms governing Cd uptake in rice remain largely unknown. This research identifies the transcription factor OsNAC5 in Oryza sativa as a positive regulator of the Cd transporter gene OsNRAMP1, thereby influencing Cd uptake. OsNAC5 is predominantly expressed in the roots, resides in the nucleus, and is upregulated by Cd-induced hydrogen peroxide (H2O2). Knocking out OsNAC5 results in lower Cd concentrations in both shoots and roots and heightens sensitivity to Cd. The expression of OsNRAMP1, enhanced by Cd stress, is dependent on OsNAC5. OsNAC5 binds to "CATGTG" motifs in the OsNRAMP1 promoter, activating its expression. The loss of OsNAC5 function leads to reduced Cd accumulation in rice grains. Our findings provide insights into the transcriptional regulation of Cd stress response in rice and propose biotechnological strategies to lower Cd uptake in crops.

Effective remediation of mercury (II) from aqueous solutions using CS-MnFe2O4-CoS-MWCNTs: Box-Behnken design optimization and adsorption isotherm, kinetics, and thermodynamics evaluation.

Mercury (Hg) is a hazardous heavy metal, non-biodegradable and toxic, posing a serious threat to aquatic life and human health. Therefore, the removal of Hg ions from contaminated water using effective and eco-friendly adsorbents is necessary. In the present study, three magnetic chitosan-based organic-inorganic nanocomposites, such as CS-MnFe2O4, CS-MnFe2O4-CoS, and CS-MnFe2O4-CoS-MWCNTs, were designed and constructed to investigate their capacity for adsorbing Hg ions from aqueous solutions. The physicochemical properties of prepared composites were characterized by various analyses. The BET analyses indicated their high surface area and porous structure, and the N2 adsorption-desorption showed that the modification of CS in three stages by MnFe2O4 and crosslinking reaction, CoS preparation, and MWCNT incorporation resulted in increased N2 adsorption. The XRD confirms the synthesis of MnFe2O4 and CoS in the CS matrix and also the distinct peaks of MWCNTs. The CS-MnFe2O4-CoS-MWCNTs showed acceptable thermal stability with 45% char yields and superparamagnetic properties with magnetic saturation (Ms) of 16 emu g-1. The interactive impacts of independent variables (pH, contact time, and adsorbent dosage) on the removal percentage of Hg(II) onto three prepared adsorbents, as well as the process optimization, were assessed by the Box-Behnken design. The optimum conditions were identified, and the data from the analysis of variance showed that the three independent factors (pH, contact time, and adsorbent dosage) significantly influenced the adsorption of Hg(II). The adsorption isotherm and thermodynamics analysis investigation showed that at low concentrations of Hg(II), the adsorption process was both endothermic and spontaneous for the studied adsorbents.

Synergistic photoelectrochemical detection of Cd2+ with carbon-bismuth oxybromide composites: Mechanistic insights from DFT calculations

The existences of hazardous heavy metals like cadmium (Cd) in water bodies necessitates rapid, accurate on-site detection strategies. Herein, a novel photoelectrochemical scheme for sensitive detection of Cd2+ was proposed based on the hybrid carbon-bismuth oxybromide materials (C/Bi4O5Br2 and CNTs/BiOBr). The effects of ultraviolet light (UV-light) illumination during the Cd2+ deposition and desorption stages were analyzed, revealing enhanced photocurrent responses and detection sensitivity compared with those non-illumiantion. The optimal sensitivity of 0.42079 μA/ppb (C/Bi4O5Br2 under both deposition and desorption stages) and 0.15634 μA/ppb (CNTs/BiOBr under desorption stage only) were observed with UV illumination within a Cd2+ range of 10–100 ppb. Density functional theory calculation elucidated that Cd2+ adsorption on the semiconductor surface reduced the badgaps of Bi4O5Br2 and BiOBr, which would benefit electron transfer and redox reactions. Additionally, the interaction between Cd and the semiconductor produced a Schottky barrier, which prolonged the lifetime of the photo-generated electron-hole pairs, where the electrons migrated on the semiconductor surface formed electron capture traps and induced band bending, therefore facilitated the electrons in the conduction band to react with Cd2+ deposited on the electrode surface. The study provides mechanistic insights into the photoelectrochemical processes in enhancng precise and sensitive on-site heavy metal ions detection.

Sources, Distribution, and Health Implications of Heavy Metals in Street Dust across Industrial, Capital City, and Peri-Urban Areas of Bangladesh

Heavy metals in road dusts can directly pose significant health risks through ingestion, inhalation, and dermal contact. This study investigated the pollution, distribution, and health effect of heavy metals in street dust from industrial, capital city, and peri-urban areas of Bangladesh. Inductively coupled plasma mass spectrometry (ICP-MS) examined eight hazardous heavy metals such as Zn, Cu, Pb, Ni, Mn, Cr, Cd, and Co. Results revealed that industrial areas showed the highest metal concentrations, following the order Mn > Zn > Cr > Pb > Ni > Co > Cd, with an average level of 444.35, 299.25, 238.31, 54.22, 52.78, 45.66, and 2.73 mg/kg, respectively, for fine particles (≤20 μm). Conversely, multivariate statistical analyses were conducted to assess pollution levels and sources. Anthropogenic activities like traffic emissions, construction, and industrial processing were the main pollution sources. A pollution load index revealed that industrial areas had significantly higher pollution (PLI of 2.45), while the capital city and peri-urban areas experienced moderate pollution (PLI of 1.54 and 1.59). Hazard index values were below the safety level of 1, but health risk evaluations revealed increased non-carcinogenic risks for children, especially from Cr, Ni, Cd, and Pb where Cr poses the highest cancer risk via inhalation, with values reaching 1.13 × 10−4–5.96 × 10−4 falling within the threshold level (10−4 to 10−6). These results underline the need for continuous environmental monitoring and pollution control in order to lower health hazards.

The MYC2 and MYB43 transcription factors cooperate to repress HMA2 and HMA4 expression, altering cadmium tolerance in Arabidopsis thaliana

Cadmium (Cd) represents a hazardous heavy metal, prevalent in agricultural soil due to industrial and agricultural expansion. Its propensity for being absorbed by edible plants, even at minimal concentrations, and subsequently transferred along the food chain poses significant risks to human health. Accordingly, it is imperative to investigate novel genes and mechanisms that govern Cd tolerance and detoxification in plants. Here, we discovered that the transcription factor MYC2 directly binds to the promoters of HMA2 and HMA4 to repress their expression, thereby altering the distribution of Cd in plant tissues and negatively regulating Cd stress tolerance. Additionally, molecular, biochemical, and genetic analyses revealed that MYC2 interacts and cooperates with MYB43 to negatively regulate the expression of HMA2 and HMA4 and Cd stress tolerance. Notably, under Cd stress conditions, MYC2 undergoes degradation, thereby alleviating its inhibitory effect on HMA2 and HMA4 expression and plant tolerance to Cd stress. Thus, our study highlights the dynamic regulatory role of MYC2, in concert with MYB43, in regulating the expression of HMA2 and HMA4 under both normal and Cd stress conditions. These findings present MYC2 as a promising target for directed breeding efforts aimed at mitigating Cd accumulation in edible plant roots.

Efficient removal of environmentally hazardous heavy metal ions from water by NH2-MIL-101-Fe and MOF-808-EDTA based polyether sulfone adsorbents

The potential of metal–organic frameworks (MOFs) based polymeric composites for heavy metal removal was analyzed in this study. Two mixed matrix composites, along with NH2-MIL-101-Fe and MOF-808-EDTA, were synthesized. The MOFs were synthesized using the solvothermal method, and the mixed matrix spheres (MMSs) were prepared using the facile dropping method. The MMSs were characterized, and batch adsorption studies were performed at different pH and adsorbent dosages. For both MMSs, the optimum pH was between 5–5.5, and the highest removal rates were obtained for MOF-808-EDTA spheres (94 % Hg2+, 86 % As, 80 % Mn). The optimum adsorbent dosage for MOF-808-EDTA was found to be 5.42 g/L, while for NH2-MIL-101-Fe, it was 7.13 g/L, after which the metal ion removal efficiency was reduced. Langmuir adsorption isotherm was fitted with thermodynamic evaluation of Gibbs free energy, enthalpy, and entropy. MOF-808-EDTA demonstrated a greater adsorption capacity of 272.7 mg/g (Hg2+), 151.29 mg/g (As3+), and 125.9 mg/g (Mn2+) than the other MMP. The Gibbs free energy of −20.14 (Hg2+), −12.66 (Mn2+), and −52.61 kJ/mol (As3+) were obtained from the thermodynamic study. The results indicated that the process was exothermic and spontaneous. Breakthrough column studies were performed for MOF-808-EDTA spheres using the pore-surface-diffusion model. The transient column study was conducted for individual heavy metal ion solutions using Addesign™ software to evaluate column exhaustion time, breakthrough time and length of mass transfer zone. Studies with multicomponent solutions of heavy metals also gave potentially promising results in the separation of 92 % of Hg, 84 % As, and 75 % Mn which indicates the prepared adsorbents can be used to remove heavy metal ions from industrial wastewater samples.

Surface functionalization of oil palm empty fruit bunch (OPEFB)-derived cellulose as a carboxyl platform for metal cations and dyes removal from aquatic media

The abundant oil palm empty fruit bunch (OPEFB) as by-product of palm oil milling processes exhibits a potential as an alternative cellulose feedstock for bio-adsorbent. This study aimed to produce a highly carboxylated bio-adsorbent for direct industrial application from OPEFB-based cellulose via mercerization and followed by esterification with succinic anhydride (SA) to enhance its adsorptive capability towards hazardous heavy metal and dyes ions. The modification using SA provides the carbon backbone platform for carboxyl group attachment for the contaminants. The results showed that the carboxylated cellulose had a high carboxyl content (4.39 mmol/g). Carboxylated cellulose had a higher binding capacity for adsorbates, with removal rates of 94.7%, 97.85%, 40.9%, and 90.15% for dye, Pb2+, Cu2+, and Cd2+ cations, respectively, at pH 6, 4 hours reaction time, and at room temperature. In comparison, unmodified cellulose removed only 47%, 23.1%, 2.9%, and 7.5% for dye, Pb2+, Cu2+, and Cd2+ cations, respectively. The adsorption kinetics study revealed that the adsorption process followed the pseudo-second-order model. The adsorption isotherm of these two metal cations follows the model of Langmuir very well, while Cu2+ follows the Freundlich model. Our method produces bio-adsorbents with high carboxyl content and adsorption rate in a short reaction time using OPEFB as a green precursor material that is easily scalable for industrial use.

Role of nanocomposites and nano adsorbents for heavy metals removal and dyes. An overview

Water scarcity and wastewater treatment are major concerns due to increased urbanization, industrialization, and anthropogenic practices. Various toxic heavy metals, dyes, pollutants, and chemicals are a matter of concern as they have severe environmental and ecological damage and health effects. Various advancements are being introduced in the field of adsorption using nano adsorbents and composites to deal with wastewater treatment problems. Nanocomposites are intelligent to eliminate bacteria, viruses, and inorganic and organic pollutants from wastewater due to precise binding action (chelation, absorption, ion exchange). Nanocomposite materials, such as metal nanocomposite, metal oxide nanocomposite, carbon nanocomposite, polymer nanocomposite, and membrane nanocomposite, are active in water purification. Nanoparticles (N.P.s) are important for remediation because of their large surface area, size, reactivity, and active sites. For high adsorption of pollutants, N.P.s were treated by increasing the electron density and surface area and adding functional groups. They are more capable of eliminating hazardous organic-inorganic pollutants, pathogens, and heavy metals from wastewater. This nanotechnology treatment technique has no hazardous by-products; these techniques have various regenerative efficiencies. Among various treatment methods, the adsorption process is considered one of the most highly effective treatments of heavy metals, and the functionalization of adsorbents can fully enhance the adsorption process. Therefore, four adsorbent sources are highlighted: polymeric, natural mineral, industrial by-product, and carbon nanomaterial adsorbent. The major purpose of this review is to gather up-to-date information on research and development on various adsorbents in the treatment of heavy metal and dyes from water by emphasizing the adsorption capability, the effect of pH, isotherm and kinetic model, removal efficiency, and the contact of time of every adsorbent.

Co-exposure of polyvinyl chloride microplastics with cadmium promotes nonalcoholic fatty liver disease in female ducks through oxidative stress and glycolipid accumulation

A recently discovered environmental contaminant, microplastics (MPs) are capable of amassing within the body and pose a grave threat to the health of both humans and animals. It is widely acknowledged that the combination of cadmium (Cd), a hazardous heavy metal, and microplastics produces synergistic deleterious effects. Nevertheless, the mechanism by which co-exposure to polyvinyl chloride microplastics (PVC-MPs) and Cd damages the liver of avian females is unknown. Globally prevalent and the subject of extensive research in mammals, non-alcoholic fatty liver disease (NAFLD) is a chronic liver condition. However, the mechanisms underlying injury to the avian digestive system caused by NAFLD remain unknown. Two months of co-exposure to Cd and PVC-MPs, pure water, solitary Cd exposure, single microplastics exposure, and pure water were administered to female Muscovy ducks in this study. The objective of this research was to examine whether the co-exposure of duck liver to PVC-MPs and Cd-induced oxidative stress resulted in NAFLD and subsequent apoptosis of hepatic cells. The study's findings showed that hepatocyte shape and functional activity were negatively impacted by PVC-MP and Cd buildup in liver tissues. Reduced liver organ coefficients, increased alanine aminotransferase (ALT) content, and ultrastructural damage to hepatocyte nuclei and mitochondria are indicators of this. These results point to a possible impairment in liver function. phosphoenolpyruvate carboxykinase 1 (PCK1) deficiency activates the protein kinase B/phosphatidylinositol 3-kinase (PI3K/AKT) pathway in the livers of female reproductive ducks that have been damaged by oxidative stress. This stimulation induces lipid deposition, fibrosis, and glycogen accumulation, which ultimately results in hepatocyte apoptosis. In summary, our research provides evidence that PVC-MPs cause oxidative harm to the liver, which subsequently results in fibrosis of liver tissue, hepatic glucolipid metabolism, and ultimately apoptosis.

Effective removal of toxic mixed azo dyes and Cr (VI) ions from wastewater using an integrated approach

The textile industry generates a significant amount of wastewater, including hazardous dyes, pigments, and heavy metals. The integrated approach of isolated bacterial strain and the bacterially synthesized ZnO nanoparticles was used in the removal of mixed azo dyes and Cr(VI) in a lab-scale bioreactor. It resulted in 77.19 % bromocresol purple (4th day), 50.11 % on bromocresol blue (3rd day), and 50.59 % bromocresol green (4th day) removal. Mixed azo dyes and Cr(VI) were removed using bacterial strain, which showed the maximum removal of Cr(VI) was 73.6 % at 25 ppm (3rd day) and mixed azo dyes removal was a maximum of 49.01 % at 75 ppm. A lab-scale reactor study using bacterial strain resulted in 45.89 % (5th day) of mixed azo dye and Cr(VI) removal. However, when the reactor was employed with synthetic wastewater and bacterially synthesized ZnO nanoparticles, achieved a maximum removal of 53.84 % at 120 min. Also, a phytotoxicity study on the Cicer arietinum plant with different concentrations of mixed azo dyes and chromium concentrations showed a maximum length of 5.5 cm at 100 ppm (3rd day). The bacterial strain and synthesized ZnO nanoparticles integrated technique providing an economically viable and scale-up solution for wastewater treatment techniques.

Melatonin protects against chromium induced oxidative stress-mediated changes in energy metabolism of rat hepatic, cardiac and renal tissues

Chromium (Cr) is one of the most prevalent and potentially hazardous heavy metal found in the environment that can cause carcinogenic, genotoxic, and organ-specific irreversible complications. The most severe adverse outcome of Cr on humans involves oxidative stress. Melatonin was evidenced to alleviate such stress with various mechanisms including antioxidative potential and metal chelation. Male Wistar rats were divided into 4 groups and treated for 14 days. The first group (control) was treated with vehicle; the second group was orally administered with melatonin (20 mg/kg b.w./day); the third group was injected with sodium dichromate dihydrate (5 mg/kg bw, s.c. every alternate day); and the fourth group was administered with melatonin, 30 min before Cr administration. The treatment of rats with Cr (VI) was found to affect the metabolic pathways by altering the activities of enzymes possibly through uncompetitively binding with them. The current study also demonstrated that melatonin efficiently preserved the glucose levels and blood lipid profile. Moreover, melatonin was further found to protect the activities of glycolytic, Krebs’ cycle, and ETC enzymes. Further, melatonin pre-treatment reduced the production of O2.− anion free radical and Ca2+ overload to protect the mitochondria at the ultrastructural level and reduced DNA damage to some extent. Therefore, this research strongly recommends melatonin as a therapeutic molecule against Cr-induced oxidative stress-mediated liver, heart, and kidney disorders.

Hyperconfined bio-inspired Polymers in Integrative Flow-Through Systems for Highly Selective Removal of Heavy Metal Ions

Access to clean water, hygiene, and sanitation is becoming an increasingly pressing global demand, particularly owing to rapid population growth and urbanization. Phytoremediation utilizes a highly conserved phytochelatin in plants, which captures hazardous heavy metal ions from aquatic environments and sequesters them in vacuoles. Herein, we report the design of phytochelatin-inspired copolymers containing carboxylate and thiolate moieties. Titration calorimetry results indicate that the coexistence of both moieties is essential for the excellent Cd2+ ion-capturing capacity of the copolymers. The obtained dissociation constant, KD ~ 1 nM for Cd2+ ion, is four-to-five orders of magnitude higher than that for peptides mimicking the sequence of endogenous phytochelatin. Furthermore, infrared and nuclear magnetic resonance spectroscopy results unravel the mechanism underlying complex formation at the molecular level. The grafting of 0.1 g bio-inspired copolymers onto silica microparticles and cellulose membranes helps concentrate the copolymer-coated microparticles in ≈3 mL volume to remove Cd2+ ions from 0.3 L of water within 1 h to the drinking water level (<0.03 µM). The obtained results suggest that hyperconfinement of bio-inspired polymers in flow-through systems can be applied for the highly selective removal of harmful contaminants from the environmental water.

Determining arsenic stress tolerance genes in rice (Oryza sativa L.) via genomic insights and QTL mapping with double haploid lines

Arsenic, a hazardous heavy metal with potent carcinogenic properties, significantly affects key rice-producing regions worldwide. In this study, we present a quantitative trait locus (QTL) mapping investigation designed to identify candidate genes responsible for conferring tolerance to arsenic toxicity in rice (Oryza sativa L.) during the seedling stage. This study identified 17 QTLs on different chromosomes, including qCHC-1 and qCHC-3 on chromosome 1 and 3 related to chlorophyll content and qRFW-12 on chromosome 12 related to root fresh weight. Gene expression analysis revealed eight candidate genes exhibited significant upregulation in the resistant lines, OsGRL1, OsDjB1, OsZIP2, OsMATE12, OsTRX29, OsMADS33, OsABCG29, and OsENODL24. These genes display sequence alignment and phylogenetic tree similarities with other species and engaging in protein-protein interactions with significant proteins. Advanced gene-editing techniques such as CRISPR-Cas9 to precisely target and modify the candidate genes responsible for arsenic tolerance will be explore. This approach may expedite the development of arsenic-resistant rice cultivars, which are essential for ensuring food security in regions affected by arsenic-contaminated soil and water.