Genotoxicity assessment of raw and treated water samples using Allium cepa assay: evidence from Perak River, Malaysia

Polycyclic aromatic hydrocarbons (PAHs) occurrences in water bodies, extraction techniques, detection methods, and standardized guidelines for PAHs in aqueous solutions

Polycyclic aromatic hydrocarbons (PAHs) are a carcinogenic compound comprised of benzene ring(s). They occur naturally. However, the occurrence of anthropogenic PAHs (originates from human activities and man-made structures) may contribute to water pollution, risking the public health and aquatic life. This review describes occurrences of PAHs in water bodies, extraction techniques, detection methods, and standardized guidelines for PAHs in aqueous solutions. Previous research identifies PAH contamination across freshwater bodies due to proximity to pollution sources and hydrological factors. Despite analytical advancements, accurately quantifying and characterizing PAHs in complex environmental matrices remains challenging. Overall, this review supports the Sustainable Development Goals (SDGs) no. 6 (clean water and sanitation public) and no. 14 life below water.

Genotoxic effects of NDMA-contaminated ranitidine on Allium cepa cells and unveiling carcinogenic mechanisms via DFT and molecular dynamics simulation study

This study investigated the potential genotoxic and carcinogenic effects of N-nitrosodimethylamine (NDMA), a hazardous compound found in ranitidine formulations that are used to treat excessive stomach acid. The study first examined the effects of NDMA-contaminated ranitidine formulation on Allium cepa root growth and mitotic activity. The results demonstrated dose-dependent decreases in both root growth and mitotic index indicating genotoxicity and cell division disruption. Elevated concentrations of ranitidine correlated with increased chromosomal aberrations indicating genotoxic capabilities. These outcomes underscored that NDMA contaminated ranitidine exposure triggers genotoxicity hampering cell division and inducing chromosomal aberrations. Electronic characteristics of NDMA revealed its electrophilic nature suggesting its capability to create covalent adducts with DNA bases fostering genotoxic and carcinogenic characteristics. Molecular docking analysis showed the interactions of NDMA with DNA including hydrogen bonds and carbon-hydrogen interactions with nucleotide bases forming DNA adducts. Molecular dynamics simulations showcased the dynamic behavior of the DNA-NDMA complex over time with structural fluctuations. Dynamic hydrogen bond fluctuations implied interactive intricacies between solute and solvent molecules. Overall, this study illuminates how NDMA-contaminated ranitidine could trigger DNA damage and potentially contribute to carcinogenesis. It emphasizes the urgency of minimizing exposure to this perilous and hazardous compound.

Ascorbic acid regulates in vitro and in vivo toxicogenetic effects of hydroxyurea on eukaryotic cells

Hydroxyurea (HU) exerts unique and diverse biological effects as an anti-leukemic agent, irradiation sensitizer, and HbS inducer in patients with sickle cell anemia. Herein, we assessed the potential toxicogenic and/or oxidant effects of hydroxyurea associated with ascorbic acid by in vivo examinations in Allium cepa and human cancer cells and systemically on mice tissues. Growing A. cepa roots and HCT-116 colorectal tumor cells were examined after HU and HU plus ascorbic acid exposure. DNA damage and antioxidant enzymatic activity were quantified in peripheral blood mononuclear cells (PBMC), bone marrow leukocytes and livers of mice after 7 day-HU treatment (7.5, 15 and 30 mg/kg/day) and Vitamin C 2 μM. Hydroxyurea presented toxic effects on meristematic Allium cepa cells, causing chromosomal abnormalities and reduction of mitotic index, killed HCT-116 colorectal carcinoma cells and induced DNA injuries upon mice cells (hepatocytes, bone marrow leukocytes and PBMC). Simultaneously, hydroxyurea decreased levels of CAT and GSH activities and expand lipid peroxidation. All these biochemical and physiological changes were ameliorated when associated with ascorbic acid, indicating it restored antioxidant enzymes, decreased MDA levels, removed peroxides and, consequently, presented cytoprotection against HU-provoked cellular damage in normal cells. On the other hand, antioxidants compounds may interfere on effectiveness of HU during anticancer chemotherapies.

Acute multiple toxic effects of Trifloxystrobin fungicide on Allium cepa L

Trifloxystrobin (TFS) is a strobilurin-type fungicide that should be investigated due to its risks to non-targeted organisms. The goal of this study was to assess the susceptibility of Allium cepa L. to TFS in a multi-pronged approach. For 72 h, 0.2 g/L, 0.4 g/L and 0.8 g/L doses of TFS were administered to A. cepa bulbs and the control group was treated with tap water. The toxic effects of TFS were tested, considering physiological, cytogenetic, biochemical and anatomical analyses. TFS delayed growth by reducing the rooting ratio, root elongation and weight increase. Following TFS treatments, mitotic index (MI) scores decreased, while the formation of micronucleus (MN) and chromosomal aberrations (CAs) ascended. CAs types induced by TFS were listed according to their frequency as fragment, vagrant chromosome, sticky chromosome, uneven distribution of chromatin, bridge, nucleus with vacuoles, reverse polarization and irregular mitosis. TFS provoked an increment in superoxide dismutase (SOD) and catalase (CAT) enzyme activities as well as an accumulation of malondialdehyde (MDA). Meristematic cells of A. cepa roots treated with TFS had various anatomical damages, including damaged epidermis, flattened cell nucleus, damaged cortex and thickness in the cortex cell wall. All damages arising from TFS treatments exhibited dose-dependency. The findings of the present study revealed the serious toxicity of TFS in a non-targeted plant. It should not be neglected to evaluate the potential hazards of TFS with different toxicity tests.

Evaluation of cytotoxicity and genotoxicity effects of refractory pollutants of untreated and biomethanated distillery effluent using Allium cepa

Environmental pollution caused by the discharge of raw and partly treated distillery effluent has become a serious and threatening problem due to its high pollution load. The aim of the present study was to assess the physicochemical load in alcohol distillery effluent before and after biomethanation treatment and the cyto- and genotoxicity effects of refractory pollutants emanated in raw/untreated and biomethanated distillery effluent on the ultrastructural and biochemical responses of Allium cepa root tip cells. Physicochemical analysis revealed high biochemical oxygen demand (BOD: 47840-36651 mg L^-1), chemical oxygen demand (COD: 93452-84500 mg L^-1) and total dissolved solids (TDS: 64251-74652 mg L^-1) in raw and biomethanated effluent along with metal(loid)s (Fe: 456.152-346.26; Zn: 1.654-1.465; Cu: 0.648-0.562; Ni: 1.012-0.951, and Pb: 0.264 mg L^-1) which were beyond the safe discharge values prescribed by the environmental regulatory agencies. The UV-Visible and Fourier transform infrared spectrophotometry analyses confirmed the high levels of organic, inorganic, and mixed contaminants discharged in raw and biomethanated distillery effluents. Furthermore, GC-MS analysis characterised chemical contaminants, such as hexadecanoic acid, butanedioic acid, bis(trimethylsilyl) ester; hexadecane, 2,6,11,15-tetramethyl, stigmasterol, and β-sitosterol trimethylsilyl ether that have been reported as androgenic-mutagenic, and endocrine disrupting chemicals by the United States Environmental Protection Agency (U.S. EPA). The cytotoxicity measured by A. cepa showed dose depended inhibition root growth inhibition and simultaneous reduction in mitotic index in tested effluents. The chromosomal aberrations studies resulted in laggard chromosomes, sticky chromosomes, vagrant chromosomes, chromosome loss, c-mitosis, chromosome bridge, abnormal metaphase, and disturbed anaphase as found in a dose-dependent manner. Furthermore, dose-dependent enhancement in the levels of malondialdehyde, hydrogen peroxide, and antioxidative enzymes, such as superoxide dismutase, ascorbate peroxidase, and catalase were found to be higher in raw effluents treated root cells compared to biomethanated distillery effluent. Analysis of ultrastructural changes in root tip cells by TEM analysis revealed dramatic changes in the morphology of cell organelles and accumulation of metallic elements in and on the surface tissues. The results concluded that the discharged distillery effluents retained certain toxic pollutants which imposed cytotoxic and genotoxic hazards to A. cepa. Thus, for the sake of environmental protection, the raw as well as the disposed biomethanated effluent must be efficiently treated before its dumping into the terrestrial ecosystem.

The occurrence of non-steroidal anti-inflammatory drugs (NSAIDs) in Malaysian urban domestic wastewater

The water stream has been reported to contain non-steroidal anti-inflammatory drugs (NSAIDs), released from households and premises through discharge from Sewage Treatment Plant (STP). This research identifies commonly consumed NSAIDs namely ibuprofen (IBU), diclofenac (DIC), ketoprofen (KET) and naproxen (NAP) in the influent wastewater from two urban catchments (i.e. 2 STPs). We expand our focus to assess the efficiency of monomer (C18) and dimer (HLB) types of sorbents in the solid phase extraction method followed by gas chromatography mass spectrometry (GCMS) analysis and optimize model prediction of NSAIDs in the influent wastewater using I-Optimal design. The ecological risk assessment of the NSAIDs was evaluated. The HLB produced reliable analysis for all NSAIDs under study (STP1: 6.7 × 10^-3 mg L^-1 to 2.21 × 10^-1 mg L^-1, STP2: 1.40 × 10^-4 mg L^-1 to 9.72 × 10^-2 mg L^-1). The C18 however, selective to NAP. Based on the Pearson proximity matrices, the DIC_HLB can be a good indicator for IBU_HLB (0.565), NAP_C18 (0.721), NAP_HLB (0.566), and KET_HLB (0.747). The optimized model prediction for KET and NAP based on DIC are successfully validated. The risk quotients (RQ) values of NSAIDs were classified as high (RQ > 1), medium (RQ, 0.1-1) and low (RQ, 0.01-0.1) risks. The optimized models are beneficial for major NSAIDs (KET and NAP) monitoring in the influent wastewater of urban domestic area. An upgrade on the existing wastewater treatment infrastructure is recommended to counteract current water security situation.

Strength enhancement of concrete using incinerated agricultural waste as supplementary cement materials

The potassium (K) and sodium (Na) elements in banana are needed for hydration reaction that can enhance the strength properties of concrete. This research aims (a) to determine the material engineering properties of banana skin ash (BSA) and concrete containing BSA, (b) to measure the strength enhancement of concrete due to BSA, and (c) to identify optimal application of BSA as supplementary cement materials (SCM) in concrete. The BSA characterization were assessed through X-ray fluorescence (XRF) and Blaine’s air permeability. The workability, compressive strength, and microstructures of concrete containing BSA were analysed using slump test, universal testing machine (UTM) and scanning electron microscope (SEM). A total of 15 oxides and 19 non-oxides elements were identified in BSA with K (43.1%) the highest and Na was not detected. At 20 g of mass, the BSA had a higher bulk density (198.43 ± 0.00 cm³) than ordinary Portland cement (OPC) (36.32 ± 0.00 cm³) indicating availability of large surface area for water absorption. The concrete workability was reduced with the presence of BSA (0% BSA: > 100 mm, 1% BSA: 19 ± 1.0 mm, 2%: 15 ± 0.0 mm, 3% BSA: 10 ± 0.0 mm). The compressive strength increased with the number of curing days. The concrete microstructures were improved; interfacial transition zones (ITZ) decreased with an increase of BSA. The optimal percentage of BSA obtained was at 1.25%. The established model showed significant model terms (Sum of Squares = 260.60, F value = 69.84) with probability of 0.01% for the F-value to occur due to noise. The established model is useful for application in construction industries.

Biomarker-based evaluation of cytogenotoxic potential of glyphosate in Vigna mungo (L.) Hepper genotypes

Herbicides have proven to be a boon for agricultural fields. Their inherent property to kill weeds and unwanted vegetation makes them an essential biological tool for farmers and agricultural systems. Besides being capable of destroying weeds, they also exhibit certain effects on non-target crop plants. In the present study, a laboratory experiment was performed to assess the effect of glyphosate on Vigna mungo root meristem cells. Seeds of five different genotypes of V. mungo were treated with a series of concentrations of glyphosate ranging from 1 to 10 mM, and their effects on mitotic cell division were studied. Healthy and uniform-sized seeds were selected and were allowed to grow in Petri plates for 3 days, and all the doses were maintained in triplicates. Roots were fixed at day 3 after treatment (DAT) for cytological microscopic slide preparation. The results obtained indicate the dose-dependent reduction in the mitotic index in all the genotypes and an increase in the percentage of chromosomal aberrations (CAs) and relative abnormality rate (RAR). Most commonly observed chromosome aberrations at lower doses (< 6 mM) were fragments, stickiness, and disoriented metaphase, while at higher doses (6 to 10 mM) bridges, laggards, spindle disorientation, and clumping were obvious. The increase in the percentage of CAs and RAR indicates the inhibitory effect of glyphosate on cell cycle progression at various stages in root tip cells. The present study is a fine example of a biomarker-based genotoxic assessment of mitotic damage caused by glyphosate.

Dataset on specific UV absorbances (SUVA254) at stretch components of Perak River basin

Perak River basin is in Perak state of Peninsular Malaysia. In this research, the river stretch serves as water intake for domestic, agricultural and industrial purposes in Perak Tengah, Hilir Perak and Manjung regions. It is located in mixed use area whilst exposing the river to anthropogenic elements. The sampling locations were conducted at selected points of Perak River namely Tanjung Belanja Bridge (TBB), Water Treatment Plant Parit (WTPP), Parit Town discharge (PTD), Water Treatment Plant Senin (WTPS) and Water Treatment Plant Kepayang (WTPK). The existence of aromatic hydrocarbons in freshwater samples was pre-assessed via qualification analysis; specific ultraviolet absorbance (SUVA₂₅₄) method at 254 nm of wavelength. The SUVA dataset were 48.38 L/mg-m (TBB), 50.54 L/mg-m (WTPP), 8.05 L/mg-m (PTD), 85.75 L/mg-m (WTPS) and 217.39 L/mg-m (WTPK). The SUVA₂₅₄ values of fresh water at the river basin have exceeded the water quality standards value equivalent to 2.0 L/mg-m permitted by the Environmental Protection Agency of United States. The exceeding values were an indication of a large portion of aromatic compounds in the water. Qualification analyses evident the existence of water pollutants at treacherous concentrations for public health in freshwater samples of Perak River basin. Thus, this research has presented important findings towards further research and countermeasure for a better alternative of water treatment in Malaysia.

Application of response surface methodology for the optimization of polycyclic aromatic hydrocarbons degradation from potable water using photo-Fenton oxidation process

Polycyclic aromatic hydrocarbons (PAHs) are carcinogenic compounds, composed of benzene rings. The objective of this research was to identify the optimum condition for the degradation of PAHs contaminated water using photo-Fenton oxidation process via response surface methodology (RSM). Aqueous solution was prepared and potable water samples were collected from water treatment plants in Perak Tengah, Perak, Malaysia in September 2016. The reaction time, pH, molarity of H₂O₂ and FeSO₄ were analyzed followed by RSM using aqueous solution. A five level central composite design with quadratic model was used to evaluate the effects and interactions of these parameters. The response variable was the percentage of total organic carbon (TOC) removal. PAHs quantification was done using gas chromatography mass spectrometry analysis. The regression line fitted well with the data with R² value of 0.9757. The lack of fit test gives the highest value of Sum of Squares (15,666.64) with probability F value 0.0001 showing significant quadratic model. The optimum conditions were established corresponding to the percentage of TOC removal. The PAHs removal efficiency for potable water samples ranged from 76.4% to 91% following the first order of kinetic rates with R² values of >0.95. Conventional water treatment techniques are not effective for PAHs removal. Thus, advanced oxidation processes may be considered as an alternative to conventional water treatment techniques in Malaysia and other developing countries.

Toxicological responses of surfactant functionalized selenium nanoparticles: A quantitative multi-assay approach

The utilization of selenium nanomaterials (Se Nps) in material and biological science is quickly growing, crafting an imperative need for toxicological evaluation of the exposure prospective and environmental consequences of Se Nps. The combination of quantitative multi-assay approach into environmental toxicological analysis has provided novel opportunities to build up effective markers and scrutinize the means of venomous nature of Se Nps in the current study. In the present work, we analyzed the toxicological effect of bare and surface functionalized Se Nps by using multi assay viz. seed germination studies as a function of concentration of SeNps and by using antifungal assays. The influence of SeNps on bacterial activities were also investigated by using the S. aureus, E. coli, P. aeruginosa and S. typhi bacterial strains as widespread marker species for antibacterial studies. The ocular assessment of chlorophyll content was maximum for Brij coated Se NPs (98%) as compared to bare (20%), SDS (45%) and CTAB (38%) coated SeNps. The existence of chromosomal aberrations in root meristems of A. cepa(A. cepa) with computed MI values of 16, 25, 33 and 52% for bare, CTAB, SDS and Brij coated particles has indicated the genotoxic effects of SeNps. The biocompatible nature of Brij coated Se Nps was observed from the faster mobility of DNA in gel electrophoresis studies. The investigational studies in the current work appraise the toxicity and measure the competence of obtained data to characterize possibilities of probable threats, prominence of data requirement and breaches that must be filled to diminish the ambiguities about the safe use of Se Nps.