Poisoning Research Articles

Evaluation of anti- inflammatory and analgesic activity of Bhasmas in experimental animal models

Acute toxicity studies of both the bhasmas showed no mortality at 2000 mg/kg.The Scanning electron microscopy of both Tamra and Lauha bhasma indicated the nanomaterial characteristics which justifies claim of Ayurvedic bhasmas as ancient nanomaterials. Tamra and Lauha bhasma were found to be effective as anti-inflammatory agent in acute models of inflammation. It inhibits all phases of inflammation induced by carrageenan. Tamra and Lauha bhasma were found to be effective as anti-inflammatory agent in chronic model of inflammation. It significantly inhibits wet as well as dry weight of cotton pellet granuloma at highest doses only. Analgesic activity of both Tamra and Lauha bhasma in hot plate and tail immersion models were found to be significant at 120-240 mins. Analgesic activity of both Tamra and Lauha bhasma in acetic acid models were found to be non-significant in nature, while found to be significant at late phase in formalin induced model. Tamra and Lauha bhasma also were found to have significant anti-arthritic activity in animal study.The whole pharmacological investigations were indicated that activity was only significant at therapeutic and more than therapeutic dose but nonsignificant at dose lower than therapeutic doses. The obtained results indicates the anti-inflammatory and analgesic potential of both these bhasmas probably by inhibiting inflammatory mediators.

Metallacarboranes in Medicinal Chemistry: Current Advances and Future Perspectives.

Metallacarboranes, exemplified by cobalt bis(dicarbollide) ([COSAN]-), have excelled their historical metallocene analogue label to become promising in drug design, medical studies, and fundamental biological research. Serving as a unique platform for conjugation with biomolecules, they also constitute an auspicious building block for biologically active derivatives and a carrier for cellular transport of membrane-impermeable cargos. Modified [COSAN]- exhibits specific antimicrobial, antiviral, and anticancer actions showing promise for preclinical trials. Contributing to the ongoing development in medicinal chemistry, metallacarboranes offer desirable physicochemical properties and low acute toxicity. This article presents a critical look at metallacarboranes in the context of their application in medicinal chemistry, emphasizing [COSAN]- as a potential game-changer in drug design and biomedical sciences. As medicinal chemistry seeks innovative building blocks, metallacarboranes emerge as an important novelty with versatile solutions and promising implications.

Bioactive Components Analysis and Pharmacological Properties of Extracts and Metabolites of Lichen Umbilicaria crustulosa

Lichens, a diverse group of organisms, have a unique structure consisting of fungal filaments and photosynthetic partner cells. This research conducted a comprehensive chemical analysis and evaluation of the anti-inflammatory and antioxidant properties of methanolic and acetone extracts from Umbilicaria crustulosa lichen, along with its isolated metabolites. The process involved separating atranorin and chloratranorin fractions, physodic acid, and gyrophoric acid. Secondary metabolites were identified using chromatographic and spectroscopic data. The total polyphenols content was determined spectrophotometrically. This study examined the antioxidant activity of extracts of the lichen U. crustulosa and the isolated fractions using three methods: DPPH scavenging activity, ABTS scavenging activity, and reducing power. This study also evaluated the acute oral toxicity and the anti-inflammatory activity of the extracts in Wistar albino rats. A higher content of the total phenolic compounds was found in the acetone extract, but antioxidant and anti-inflammatory activities were more prominent in the methanolic extract. The isolated atranorin and chloratranorin fractions and compound physodic acid showed the highest antioxidant activity. No toxic effects were noted in the acute oral toxicity study. This study highlights the potential of the investigated lichen as a valuable source of novel biological agents.

The Correlation between Chemical Ingredients and Acute Toxicity of Psoraleae Fructus and Two Classic Prescriptions

Objective: To compare the acute toxicity and chemical ingredients of Psoraleae Fructus (PF) with those of two classic prescriptions, Ershen Wan (ESW) and Sishen Wan (SSW). Methods: Based on classical toxicological methods, body weight, food and water consumption, lethal conditions, and toxic reactions were recorded after administering single oral doses of PF, ESW, and SSW. The 50% lethal dose (LD50) values of PF and ESW and the maximum tolerance dose (MTD) of SSW were determined. In addition, PF, ESW, and SSW constituents were detected using ultra-high-performance liquid chromatography/mass spectrometry (UPLC-MS), and the spectrum-toxicity correlation was analyzed. Results: The LD50 of PF and ESW were 53.9 g/kg/d (46.2–63.0 g/kg/d, 95% CL) and 68.3 g/kg/d (59.0–78.9 g/kg/d, 95% CL), which were respectively about 40 times and 50 times of the human daily dosage. The MTD of SSW was 41.0 g/kg/d, indicating the highest safety. The chemical ingredients and toxicity correlation analyses inferred that compatibility reduced the contents of 13 potential hepatotoxin compounds in PF. Conclusions: The classic compatibility of ESW and SSW effectively attenuated the hepatotoxicity of PF, which was related to the reduced content of potentially toxic substances, particularly coumarins. This study explored the principles of attenuating the toxicity of classic prescriptions to provide a reference for the rational clinical use of PF.

Meta-Analysis of 5-Fraction Preoperative Radiotherapy for Soft Tissue Sarcoma.

Studies investigating preoperative 5-fraction radiation therapy (RT) for soft tissue sarcoma (STS) are limited. We performed a meta-analysis to determine the efficacy and safety of this treatment paradigm. This study-level meta-analysis was conducted using Bayesian methods. Statistical estimation for risk of outcome rates was conducted by posterior mean and 95% highest posterior density (HPD) intervals. Studies with 2-year local control (LC) and description of major wound complications (MWC) per the CAN-NCIC-SR2 study were included and served as the primary endpoints. Secondary endpoints included rates of acute and late toxicity. A total of 10 studies were identified and 7 met the inclusion criteria. Subgroup analyses were performed for ≥30 Gy vs <30 Gy. A total of 209 patients from 7 studies were included. Five studies used ≥30 Gy (n=144), and 2 studies <30 Gy (n=64). Median follow-up was 29 months (range: 21 to 57mo). Primary tumor location was lower extremity in 68% and upper extremity in 22%. Most tumors were intermediate or high grade (95%, 160/169), and 50% (79/158) were >10cm. The two-year LC for the entire cohort was 96.9%, and the rate of MWC was 30.6%. There was a trend toward improved LC with ≥ 30 Gy (95% HPD: 0.95 to 0.99 vs 0.84 to 0.99). There was no difference in MWC (95% HPD: 0.18 to 0.42 vs 0.17 to 0.55) or late toxicity between the groups. Preoperative 5-fraction RT for STS demonstrates excellent 2-year LC with MWC and toxicity similar to standard fractionation preoperative RT. Multi-institutional trials with a universal RT protocol are warranted.

Success of Ultra-low Dose Radiation Therapy for Primary Cutaneous B-cell Lymphoma.

Primary cutaneous B-cell lymphoma (PCBCL) is a relatively rare disease, associated with 5-year overall survival of nearly 95% when treated with external beam radiation therapy (EBRT) alone. However, standard EBRT doses yield acute skin toxicity in more than 70% of patients and grade 3 to 4 acute skin toxicity in nearly 10% of patients. Consequently, the PCBCL treatment paradigm is shifting towards lower EBRT doses. This study evaluates our early experience with ultra-low dose EBRT (total dose of 4 Gy in 2 fractions) for PCBCL. Four biopsy-confirmed PCBCL lesions (1 anterior thigh and 3 chest) in 2 male patients were treated with 2 Gy×2 fraction EBRT using electrons through a clinical setup. The anterior thigh lesion was treated using a clamshell to protect the scrotum from scatter dose. Treatment was achieved using 9 MeV electrons to the 85% isodose line using no bolus, with follow-up every 4 months and potential retreatment if no visible response at 8 to 9 months. All lesions demonstrated a response to EBRT by 4 months, visibly manifesting as flattening with changes in pigmentation. At the last follow-up (20, 20, 16.5, and 4 mo, respectively), all lesions had flattened with no evidence of local recurrence and no skin toxicity. Treatment of PCBCL with ultra-low dose EBRT to 4 Gy total dose in 2 fractions provides durable local control with zero skin toxicity. These results are encouraging for both the success of treatment and the potential to use similarly low doses for retreatment should patients exhibit local recurrence.

Radiation enhancement using focussed ultrasound-stimulated microbubbles for breast cancer: A Phase 1 clinical trial.

Preclinical studies have demonstrated that tumour cell death can be enhanced 10- to 40-fold when radiotherapy is combined with focussed ultrasound-stimulated microbubble (FUS-MB) treatment. The acoustic exposure of microbubbles (intravascular gas microspheres) within the target volume causes bubble cavitation, which induces perturbation of tumour vasculature and activates endothelial cell apoptotic pathways responsible for the ablative effect of stereotactic body radiotherapy. Subsequent irradiation of a microbubble-sensitised tumour causes rapid increased tumour death. The study here presents the mature safety and efficacy outcomes of magnetic resonance (MR)-guided FUS-MB (MRgFUS-MB) treatment, a radioenhancement therapy for breast cancer. This prospective, single-center, single-arm Phase 1 clinical trial included patients with stages I-IV breast cancer with in situ tumours for whom breast or chest wall radiotherapy was deemed adequate by a multidisciplinary team (clinicaltrials.gov identifier: NCT04431674). Patients were excluded if they had contraindications for contrast-enhanced MR or microbubble administration. Patients underwent 2 to 3 MRgFUS-MB treatments throughout radiotherapy. An MR-coupled focussed ultrasound device operating at 800 kHz and 570 kPa peak negative pressure was used to sonicate intravenously administrated microbubbles within the MR-guided target volume. The primary outcome was acute toxicity per Common Terminology Criteria for Adverse Events (CTCAE) v5.0. Secondary outcomes were tumour response at 3 months and local control (LC). A total of 21 female patients presenting with 23 primary breast tumours were enrolled and allocated to intervention between August/2020 and November/2022. Three patients subsequently withdrew consent and, therefore, 18 patients with 20 tumours were included in the safety and LC analyses. Two patients died due to progressive metastatic disease before 3 months following treatment completion and were excluded from the tumour response analysis. The prescribed radiation doses were 20 Gy/5 fractions (40%, n = 8/20), 30 to 35 Gy/5 fractions (35%, n = 7/20), 30 to 40 Gy/10 fractions (15%, n = 3/20), and 66 Gy/33 fractions (10%, n = 2/20). The median follow-up was 9 months (range, 0.3 to 29). Radiation dermatitis was the most common acute toxicity (Grade 1 in 16/20, Grade 2 in 1/20, and Grade 3 in 2/20). One patient developed grade 1 allergic reaction possibly related to microbubbles administration. At 3 months, 18 tumours were evaluated for response: 9 exhibited complete response (50%, n = 9/18), 6 partial response (33%, n = 6/18), 2 stable disease (11%, n = 2/18), and 1 progressive disease (6%, n = 1/18). Further follow-up of responses indicated that the 6-, 12-, and 24-month LC rates were 94% (95% confidence interval [CI] [84%, 100%]), 88% (95% CI [75%, 100%]), and 76% (95% CI [54%, 100%]), respectively. The study's limitations include variable tumour sizes and dose fractionation regimens and the anticipated small sample size typical for a Phase 1 clinical trial. MRgFUS-MB is an innovative radioenhancement therapy associated with a safe profile, potentially promising responses, and durable LC. These results warrant validation in Phase 2 clinical trials. clinicaltrials.gov, identifier NCT04431674.

Assessment of the Hazard and Ecotoxicity of the Residues of Paiche Leather Dyed with Natural and Synthetic Colourants: A Focus on Environmental Sustainability

The aim of this research was to assess the hazardousness and ecotoxicity of paiche leather (Arapaima gigas) dyed with natural colourants (turmeric and purple corn) versus synthetic colourants (anilines). To determine hazardousness, the methodology included the assessment of flammability, corrosivity, reactivity to H2S and HCN, toxicity from metals, and organic compounds of dyed leather. Additionally, its ecotoxicity was determined using the California red worm (Eisenia fetida) as a bioindicator through a bioassay, with treatments at 0.02, 0.04, 0.08, 0.16, and 0.20 g of leather/g of substrate, including undyed leather and a negative control in the investigation. The hazardousness analysis results indicated that leather samples dyed with both natural and synthetic colourants are not hazardous. However, the concentrations of chromium, nickel, cadmium, and lead exceed the permitted values for their use in footwear according to the European Union. Regarding ecotoxicity, the results demonstrate that acute toxicity to E. fetida is lower for natural colourants compared to synthetic colourants, where 100% mortality occurs at concentrations between 0.04 and 0.08 g of leather/g of the substrate. Concerning chronic toxicity, after 12 weeks of exposure, the tolerance concentration for undyed paiche leather is 0.035 g of leather/g of the substrate, and for leather dyed with purple corn and turmeric, it is 0.2 g of leather/g of the substrate. It is shown that the active compounds of natural colourants have a positive effect on worm survival, and it is concluded that paiche leather dyed with these colourants presents environmental advantages over leather dyed with synthetic colourants.

Bisphenol S exposed changes in intestinal microflora and metabolomics of freshwater crayfish, Procambarus clarkii

Bisphenol S (BPS), a typical endocrine-disrupting chemical (EDC), can cause hepatopancreas damage and intestinal flora disturbance. Comprehensive studies on the mechanisms of acute toxicity in crustaceans are lacking. In this study, 16S rRNA and liquid chromatography were used to investigate intestinal microbiota and metabolites of freshwater crayfish (Procambarus clarkii). In this study, freshwater crayfish were exposed to BPS (10 µg/L and 100 µg/L). The results showed a significant decrease in catalase (CAT) and superoxide dismutase (SOD) activities after exposure to BPS, which inhibited the Nrf2-Keap1 signaling pathway and induced oxidative stress toxicity in freshwater crayfish. In addition, BPS exposure induced the structural changes of intestinal microbial in the freshwater crayfish, showing different patterns of effects. The number of potentially pathogenic bacteria increased, such as Citrobacter, Hafnia-Obesumbacterium, and RsaHf231. A total of 128 different metabolites were analyzed by LC-MS/MS. The inositol and leukotriene (LT) contents in the hepatopancreas of freshwater crayfish were significantly decreased after 10 µg/L BPS exposure, which in turn led to the accumulation of lipids causing hepatopancreas damage. In conclusion, when the concentration of BPS in the water environment exceeded 10 µg/L, the freshwater crayfish intestinal microbiota was dysbiosis and the hepatopancreas metabolism was disturbed.

LINAC–BASED STEREOTACTIC ARRHYTHMIA RADIOABLATION (STAR) FOR PAROXYSMAL ATRIAL FIBRILLATION IN ELDERLY: A PROSPECTIVE PHASE II TRIAL

Abstract Background and Aims The aim of this trial is to investigate the feasibility of radiotherapy for the treatment of paroxysmal atrial fibrillation (AF) in elderly patients. Method inclusion criteria were: age &amp;gt; 70 years, symptomatic AF, antiarrhythmic drugs failure or intolerance. All patients underwent to 4D cardiac Computed Tomography simulation. The clinical target volume was identified in the area around pulmonary veins (PV). STAR was performed with a total dose of 25 Gy (single fraction) delivered in 3 minutes. Results Twenty patients were enrolled and 18 underwent STAR. One patient withdrew informed consent before treatment and 1 patient was excluded due to unfavorable esophagus position. With a median follow–up (FU) of 16 months (range 12–23), no acute toxicity more than grade 3 was reported. Five patients had a grade 1 esophagitis 24 hours after STAR; eight patients had an asymptomatic grade 1 pericardial effusion, one patient had a torsade de pointes treated effectively by electrical cardioversion and subsequent cardiac ICD implantation. Most patients had a significant reduction in AF episodes. Five patients, due to arrhythmias recurrences after STAR, performed electrophysiological study documenting successful PV isolation. Finally, a significant improvement of quality of life was documented (48 ± 15 at enrollment vs 75 ± 15 at 12 months FU; p &amp;lt; 0.001). Conclusion The present phase II trial demonstrated the feasibility of STAR in paroxysmal AF elderly patients and its potential role in increasing the quality of life. Surely, more robust data are needed about safety and efficacy.

Current scenario of fused pyrimidines with in vivo anticancer therapeutic potential.

Cancer, characterized by uncontrolled cell growth and metastasis, is responsible for nearly one in six deaths and represents a severe threat to public health worldwide. Chemotherapy can substantially improve the quality of life and survival of patients with cancer, but anticancer chemotherapeutics are associated with a range of adverse effects. Moreover, almost all currently available anticancer chemotherapeutics could develop drug resistance over a period of time of application in cancer patients and ultimately lead to cancer relapse and death in 90% of patients, creating an urgent need to develop new anticancer agents. Fused pyrimidines trait the inextricable part of DNA and RNA and are vital in numerous biological processes. Fused pyrimidines can act on various biological cancer targets and have the potential to address drug resistance. In addition, more than 20 fused pyrimidines have already been approved for clinical treatment of different cancers and occupy a prominent place in the current therapeutic arsenal, revealing that fused pyrimidines are privileged scaffolds for the development of novel anticancer chemotherapeutics. The purpose of this review is to summarize the current scenario of fused pyrimidines with in vivo anticancer therapeutic potential along with their acute toxicity, metabolic profiles as well as pharmacokinetic properties, toxicity and mechanisms of action developed from 2020 to the present to facilitate further rational exploitation of more effective candidates.

STUDY OF ACUTE AND SUB-ACUTE TOXICITY OF A MEDICATION BASED ON SPIDER VENOM EXTRACT

Homeopathy is a regulatory therapy. The effectiveness of homeopathic therapy does not depend on the dose of the drug, but on the frequency of its repetitions. The composition of homeopathic preparations includes a wide range of natural and synthetic active substances: minerals; chemical substances; substances of plant origin; microorganisms, including fungi, bacteria, viruses, and plant parasites; substances of animal origin; and human materials, which may include tissues, secretions, hormones, and genetically homogeneous cell lines. One such substance is an extract of spider venom (Tarantul cubensis D6), which remains active in pharmaceutical preparation for a long time. The drug is selectively absorbed in inflamed tissues, differentiating them from healthy cells and suppressing inflammation. The drug is also effective in necrotic and proliferative processes. It is used for the treatment of panaritium in the initial stage, skin ulcers, necrobacillosis, and necrosis of the soft tissues of the animal. Any materials of animal or human origin are potentially dangerous for human and animal health, as they may contain toxic or pathogenic substances. Therefore, the study of the acute and subacute toxicity of spider venom extract is one of the stages of establishing the toxicological parameters of the drug. The use of the drug in a therapeutic dose caused an increase in animal body weight, hemoglobin concentration, number of leukocytes, erythrocytes, hematocrit value, average erythrocyte volume (MCV), average hemoglobin content in erythrocytes (МСН), average concentration of hemoglobin in erythrocytes (МСНС), number of platelets, and AST activity against the background of a slight decrease in total protein content, creatinine, urea, and ALT activity. The use of the drug in a 10-fold therapeutic dose caused an increase in animal body weight, creatinine, urea, ALT, and AST activity against the background of a decrease in the concentration of hemoglobin, the number of leukocytes and erythrocytes, the value of hematocrit, the average volume of erythrocytes (MCV), the average content of hemoglobin in erythrocytes (МСН), the average concentration of hemoglobin in erythrocytes (МСНС), the number of platelets, and the content of total protein.

Metabolic Composition of Methanolic Extract of the Balkan Endemic Species Micromeria frivaldszkyana (Degen) Velen and Its Anti-Inflammatory Effect on Male Wistar Rats

Extracts from medicinal plants are widely used in the treatment and prevention of different diseases. Micromeria frivaldszkyana is a Balkan endemic species with reported antioxidant and antimicrobial characteristics; however, its phytochemical composition is not well defined. Here, we examined the metabolome of M. frivaldszkyana by chromatography–mass spectrometry (GC-MS), ultra-performance liquid chromatography–mass spectrometry (UPLC-MS-MS), and inductively coupled plasma mass spectrometry (ICP-MS). Amino acids, organic acids, sugars, and sugar alcohols were the primary metabolites with the highest levels in the plant extract. Detailed analysis of the sugar content identified high levels of sucrose, glucose, mannose, and fructose. Lipids are primary plant metabolites, and the analysis revealed triacylglycerols as the most abundant lipid group. Potassium (K), magnesium (Mg), zinc (Zn), and calcium (Ca) were the elements with the highest content. The results showed linarin, 3-caffeoil-quinic acid, and rosmarinic acid, as well as a number of polyphenols, as the most abundant secondary metabolites. Among the flavonoids and polyphenols with a high presence were eupatorin, kaempferol, and apigenin—compounds widely known for their bioactive properties. Further, the acute toxicity and potential anti-inflammatory activity of the methanolic extract were evaluated in Wistar rats. No toxic effects were registered after a single oral application of the extract in doses of between 200 and 5000 mg/kg bw. A fourteen-day pre-treatment with methanolic extract of M. frivaldszkyana in doses of 250, 400, and 500 mg/kg bw induced anti-inflammatory activity in the 1st, 2nd, and 3rd hours after carrageenan injection in a model of rat paw edema. This effect was also present in the 4th hour only in the group treated with a dose of 500 mg/kg. In conclusion, M. frivaldszkyana extract is particularly rich in linarin, rosmarinic acid, and flavonoids (eupatorin, kaempferol, and apigenin). Its methanolic extract induced no toxicity in male Wistar rats after oral application in doses of up to 5000 mg/kg bw. Additionally, treatment with the methanolic extract for 14 days revealed anti-inflammatory potential in a model of rat paw edema on the 1st, 2nd, and 3rd hours after the carrageenan injection. These results show the anti-inflammatory potential of the plant, which might be considered for further exploration and eventual application as a phytotherapeutic agent.

Daphnia magna model for the study of mycotoxins present in food: Gliotoxin, ochratoxin A and its combination

Mycotoxins are low molecular weight compounds present in food and feed. Although their effects on human health have been widely described, their mechanisms of action are still undefined. Gliotoxin (GTX) and ochratoxin A (OTA) are among the most dangerous mycotoxins produced by Aspergillus spp. Therefore, their toxicity was studied in the Daphnia magna model, which has high capacity to predict cytotoxicity and assess ecotoxicity, comparable to mammalian models. The study consisted of a series of tests to evaluate the effects of mycotoxins GTX, OTA and their combinations at different dilutions on Daphnia magna that were conducted according to standardized OECD 202 and 211 guidelines. The following assays were carried out: acute toxicity test, heartbeat, delayed toxicity test, reproduction, growth rate test. Reproducibility was determined by observing the offspring after 21 days of GTX exposure. In acute and delayed toxicity transcript levels of genes involved in xenobiotic metabolism (mox, gst, abcb1, and abcc5), and oxidative stress (vtg-SOD) were analyzed by qPCR. GTX showed acute toxicity and decreased heart rate in D. magna compared to OTA. On the other hand, OTA showed a delayed effect as evidenced by the immobility test. Both mycotoxins showed to increase genes involved in xenobiotic metabolism, while only the mycotoxin mixture increased oxidative stress. These results suggest that the mycotoxins tested could have negative impact on the environment and human health.

Ameliorated in vitro anti-cancer efficacy of methotrexate loaded zinc oxide nanoparticles in breast cancer cell lines MCF-7 & MDA-MB-231 and its acute toxicity study.

Traditional therapies often struggle with specificity and resistance in case of cancer treatments. It is therefore important to investigate new approaches for cancer treatment based on nanotechnology. Zinc oxide nanoparticles (ZnONPs) are known to exhibit anti-cancer properties by inducing oxidative stress, apoptosis, and cell cycle arrest. Methotrexate (MTX) known anti-folate shows specificity to folate receptors (FR) and interrupts healthy functioning of cells. This study proposes the use of previously characterized biocompatible Methotrexate loaded Zinc oxide nanoparticles (MTX-ZnONPs) as a dual action therapeutic strategy against breast cancer cell lines, MCF-7 (MTX-sensitive) and MDA-MB-231 (MTX-resistant). To elucidate the cytotoxicity mechanism of MTX-ZnONPs in depth In-vitro study was carried out. In vitro assays, including cell cycle analysis, apoptosis assay, and western blot analysis to study the protein expression were performed. Results of these assays, further supported the anti-cancer activity of MTX-ZnONPs showing apoptotic and necrotic activity in MCF-7 and MDA-MB-231 cell line respectively. In vivo acute oral toxicity study to identify the LD50 in animals revealed no signs of toxicity and mortality up to 550 mg/kg body weight of animal, significantly higher LD50 values than anticipated therapeutic levels and safety of the synthesized nanosystem. The study concludes that MTX-ZnONPs exhibit anti-cancer potential against breast cancer cells offering a promising strategy for overcoming resistance.

Exploring structure/property relationships to health and environmental hazards of polymeric polyisocyanate prepolymer substances-3. Aquatic exposure and hazard of aliphatic diisocyanate-based prepolymers.

The water extractability and acute aquatic toxicity of seven aliphatic diisocyanate-based prepolymer substances were investigated to determine if lesser reactivity of the aliphatic isocyanate groups, as well as increased ionization potential of the expected (aliphatic amine-terminated) polymeric hydrolysis products, would influence their aquatic behavior compared to that of previously investigated aromatic diisocyanate-based prepolymers. At loading rates of 100 and 1,000mg/L, only the substances having log Kow ≤9 exhibited more than 1% extractability in water, and a maximum of 66% water extractability was determined for a prepolymer having log Kow = 2.2. For the more hydrophobic prepolymer substances (log Kow values from 18-37), water extractability was negligible. High-resolution mass spectrometric analyses were performed on the water-accommodated fractions (WAF) of the prepolymers, which indicated the occurrence of primary aliphatic amine-terminated polymer species having backbones and functional group equivalent weights aligned to those of the parent prepolymers. Measurements of reduced surface tension and presence of suspended micelles in the WAFs further supported the occurrence of these surface-active cationic polymer species as hydrolysis products of the prepolymers. Despite these characteristics, the water-extractable hydrolysis products were practically non-toxic to Daphnia magna. All of the substances tested exhibited 48-h EL50 values of >1,000mg/L, with one exception of EL50 = 157mg/L. The results from this investigation support a grouping of the aliphatic diisocyanate-based prepolymers as a class of water-reactive polymer substances having predictable aquatic exposure and a uniformly low hazard potential, consistent with that previously demonstrated for the aromatic diisocyanate-based prepolymers.

Acute and multigenerational toxicity of polylactic acid microplastics on a copepod bioindicator

Acute and multigenerational toxicity of polylactic acid microplastics on a copepod bioindicator

Patterns and clinical outcomes of childhood poisoning presenting to a children’s emergency department in Yenagoa, Nigeria: a 10-year retrospective study

IntroductionBackground: Childhood poisoning, characterised by exposure to toxic substances, poses a global health concern with variations across regions. Despite the importance of having current information about childhood acute poisoning in...

Acute toxicity and anti-inflammatory activity of bis-thiourea derivatives

Abstract In the current work, bis-thiourea derivatives have been synthesized through condensation reaction between isothiocynates and diamines in dry acetone to form SK1 (1,2-bis(N-benzoylthioureido) benzene), SK2 (1,3-bis(N-benzoylthioureido) benzene), and SK3 (1,4-bis(N-benzoylthioureido) benzene). The structures of new synthesized derivatives were confirmed through melting point and spectroscopic technique such as 1HNMR only. The synthesized compounds were assessed for acute toxicity test and are proved free of toxicity. The derivatives were further tested as anti-inflammatory agents by in vitro lipoxygenase enzyme inhibition studies, molecular docking, and in vivo carrageenan-induced paw edema assay, and histamine-induced edema test. The overall observations presented that compounds SK1 and SK3 possess promising anti-inflammatory potential, while compound SK2 is found to be a good anti-inflammatory agent.

A Sensitive Electrochemical Aptamer Sensor for Clenbuterol Detection Based on Au NPs/Fe3O4–NH2/GN Nanocomposite

Chronic ingestion of food containing clenbuterol (CLB) in the human body can cause acute poisoning. Thus, it is essential to develop a sensitive CLB detection way. Here, a novel electrochemical aptamer sensor based on aptamer/gold nanoparticles/amino magnetic ferric oxide/graphene nanosheets (aptamer/Au NPs/Fe3O4–NH2/GN) nanocomposite has been developed. The Fe3O4–NH2 nanoparticles were self-assembled on GN, and then Fe3O4–NH2/GN nanocomposite was coated on the glassy carbon electrode (GCE) surface. Afterward, Au NPs were electrodeposited on Fe3O4–NH2/GN nanocomposite to fix the aptamer by the Au–S bonds. When CLB was added to the solution, the aptamer will specifically recognize CLB, causing current changes. Under the optimized conditions, the sensor shows better electrochemical performance (linear range is [Formula: see text][Formula: see text]M to [Formula: see text][Formula: see text]M, the detection limit is [Formula: see text][Formula: see text]M ([Formula: see text])). It has been successfully applied to the detection of CLB in actual samples. The results show that the aptamer sensor has good selectivity, stability and repeatability, which will provide a novel idea for more sensitive and quicker CLB detection.