Toxicology Commons^™

Fish Tissue Digestion And Microplastic Polymer Identification Protocol Using Open-Source Ftir Database, Shawn L. Kissinger, Vick-Ariel Privert, Jason Bystriansky, Kyle A. Grice

DePaul Discoveries

Microplastic (MP) contamination in aquatic ecosystems poses significant concerns for environmental and public health, as seafood represents a critical food source worldwide. Despite increasing evidence of MP presence in marine organisms, efficient and accessible detection methods remain essential for characterizing contamination patterns and informing regulatory frameworks. This study extracted MPs from brain, gill, intestine, liver, and muscle tissues of gilt-head bream (Sparus aurata) and European sea bass (Dicentrarchus labrax), two commercially important species from the Gulf of Cádiz, Spain, using a NaOH–HNO₃ chemical digestion protocol. Isolated particles were characterized by Fourier Transform Infrared (FTIR) spectroscopy, with …

Acute Effects Of The Psychoactive Pollutant Fluoxetine On The Antipredator Behavior Of The Gulf Killifish (Fundulus Grandis), Semyra Reus

Honors Theses

Pharmaceutical contaminants are increasingly prevalent in aquatic environments, yet their sublethal effects on ecologically relevant behaviors remain poorly understood, particularly in estuarine systems. Selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine, are of particular concern due to the conserved role of serotonin in regulating behavior across vertebrates. Here, we investigated how acute exposure to environmentally relevant concentrations of fluoxetine influences anti-predator behavior in Gulf killifish (Fundulus grandis), a key estuarine fish commonly found in saltmarsh habitats. Killifish were exposed to control (0 ng/L), low (17.8 ng/L), and high (596 ng/L) fluoxetine concentrations and subsequently tested in the presence …

An Investigation In The Physiological Effect Of Microplastic And Chemical Mixtures In The Body Length Of C. Elegans, Gregory Guantos, David M. Mares, Jennifer C. Harr Phd

Posters - 2026

• Microplastics (MP) are pieces of plastic less than 5 micrometers (mm). Microplastics are found in our environment and have even been found in the food humans consume, including in drinks from plastic bottles (Hu 2020).

• Di-butyl Phthalate (DBP) is a chemical known as a plasticizer commonly used in PVC applications, ink, fragrances, and adhesives

• Di-butyl Phthalate has been found to have negative effects on the physiological length of C. elegans (Xiyan 2018)

• Microplastics have similarly been found to decrease the physiological length of C. elegans (Schöpfer 2020)

• The combined effects of MPs and DBP include …

Perfluorooctane Sulfonate (Pfos)-Induced Disruption Of Mitochondrial Activity And Cell Adhesion In Liver Cells, Phuong Dam Nam Tran

Graduate Theses/Dissertations

Perfluorooctane sulfonate (PFOS) is a persistent environmental pollutant associated with potential hepatoxic effects and other health risks. Despite its widespread distribution, the mechanisms underlying its toxicities remain to be fully understood. To investigate PFOS toxicology, my study utilized HepG2 and THLE-2 human hepatic cell models to replicate conditions reflecting PFOS accumulation in the liver. Cell viability, cell stress, and cell death assays were conducted to assess the toxicological influence of the chemical on both cell lines. Total RNA extraction was performed, followed by cDNA sequencing, and RT-qPCR. The XTT viability assay revealed a dose-dependent decrease in number of viable cells …

Unsaturated Fatty Acid Oil-Based Microdroplets: A Promising Novel Class Of Microdroplets, Ramiz S. Alejilat

Seton Hall University Dissertations and Theses (ETDs)

Droplet-based microfluidics has rapidly advanced numerous fields, including chemistry, biology, materials science, medicine, food science, and cosmetics. In these systems, fluorocarbon oil combined with fluorinated surfactants is the preferred medium for fluid encapsulation, offering exceptional stability and biocompatibility essential for sensitive biological and chemical processes. However, growing concerns about the environmental and biological risks associated with fluorinated chemicals have prompted a search for alternatives.

This study is the first to explore the use of unsaturated fatty acids derived from emu oil for microdroplet formation. We characterized droplet formation based on flow rates and the presence non-fluorinated surfactant at a certain …

Developing A Small Molecule To Inhibit Hsf1 Expression In Cancer And Evaluating Natural Genetic Variation In Small Molecule Toxicity., Michaela Kendal Foley

Theses and Dissertations

Each year cancer affects nearly 20 million people worldwide and genetic differences across populations can impact cancer onset and progression. Specifically, tumors with high levels of HSF1, the master regulator of the cytoprotective heat shock response (HSR), are correlated with poor patient outcomes in multiple cancers such as prostate, breast, and melanoma. Subsequently, the development of pharmacological inhibitors of HSF1 represents a promising strategy for anticancer therapeutics. Using a luciferase-based transcriptional reporter, two small molecule libraries were screened for inhibitors of HSF1 expression in human embryonic kidney cells, yielding ten compounds that decrease HSF1 expression. To identify if cancer lines …

Assessing The Behavioral Impact Of Pyridostigmine Bromide In Rats, Noah A. Martin

Honors Theses

Pyridostigmine bromide (PB) is an organophosphate (OP) nerve agent prophylactic used to protect warfighters against chemical warfare agents. OPs inhibit the neural enzyme acetylcholinesterase (AChE) in the brain. This leads to the buildup of acetylcholine, causing respiratory failure, seizures, and death. PB functions by inhibiting ~30% of peripheral AChE temporarily, protecting the enzymes so that the body is able to restore sufficient cholinergic function post-exposure. PB does not cross the blood-brain barrier, though it may still indirectly affect toxicity in the brain due to repeated AChE inhibition throughout treatment, or by inhibition of non-target ChE’s in the blood. The aim …

Zonal Hepatocellular Responses To Acute Ethanol: Impacts On Mitochondrial Function And Metabolism, Matthew T. Savoca

MUSC Theses and Dissertations

Background: Ethanol (EtOH) consumption causes hepatocellular mitochondrial depolarization (mtDepo) and mitophagy. Here, the Aims were to develop techniques to characterize sublobular hepatocellular metabolism and the distribution of mtDepo and mitophagy after acute EtOH. Methods: Wildtype and GFP-LC3 transgenic mice were treated with EtOH or vehicle and administered the covalently labeling mitochondrial membrane potential (ΔΨ) reporter, MitoTracker Red (MTR), and/or the non-covalent ΔΨ reporter, rhodamine 123 (Rh123), prior to intravital imaging, liver fixation, or hepatocyte isolation. After in vivo MTR, hepatocytes were isolated and sorted. Enrichment in E-cadherin (ECAD) and cytochrome P4502E1 in periportal (PP) and pericentral (PC) hepatocytes, respectively, validated …

Evaluation Of The Dnazyme Gr5 For The Determination Of Lead Speciation In Natural Waters, Gaganprit Gill

Theses and Dissertations (Comprehensive)

This thesis explores the development and application of a DNAzyme-based biosensor designed to detect labile metal species in environmental samples. Real time and on-site monitoring of labile metal fractions would make a valuable contribution to environmental management, as these fractions are the most bioavailable and pose significant toxicity risks to aquatic organisms. Conventional methods for detecting labile metals, while effective, are often burdened by high costs, complexity, and lengthy processing times, making them less ideal for rapid and widespread environmental assessments.

The first manuscript of this thesis (chapter 2) establishes the fundamental capabilities of the Pb²⁺-specific DNAzyme GR5 …

Impact Of Tetrahydrocannabinol (Thc) On Daphnia Magna Heart Rate, Ashley Cosgrave

Williams Honors College, Honors Research Projects

Marijuana (Cannabis) is currently federally illegal within the United States and classified as a Schedule I drug. This leaves a large research gap on the impacts of Tetrahydrocannabinol (THC) use. Daphnia magna are frequently used as a model organism for the human heart and toxicology screenings due to their myogenic heart, similarities in physiological pathways, and sensitivity to toxins. As such, in order to bridge the research gap and uncover potential use of Daphnia magna as a model organism for humans in regard to impact on heart rate, we hypothesized that if Daphnia magna possess CB1 receptors or an equivalent …

Assessment Of Tce And Chiral Pcb Dechlorination Rate, Congener Diversity, And Enantioselectivity In Town Creek, Sc, Usa Sediment Microcosms, Catherine P. Sumner

All Dissertations

Polychlorinated biphenyls (PCBs) and trichloroethene (TCE) are ubiquitous contaminants and are recognized as persistent organic pollutants due to their extreme chemical stability. PCBs were manufactured by chlorinating biphenyls that created 209 congeners with various structures, of which 19 are chiral and can exist as a pair of stable atropisomers. PCBs have been known to cause developmental and neurological toxicity in humans and wildlife; they can act as endocrine disrupters, carcinogens, and teratogens. Sangamo Weston Inc. was an industrial plant located near Town Creek in Pickens Country, South Carolina, that manufactured capacitors and used Aroclors 1016 and 1254 as dialectic fluids …

Emerging Chromatin Regulators In Response To Heavy Metal Exposure, Wesley Saintilnord

Theses and Dissertations--Molecular and Cellular Biochemistry

Environmental exposure to heavy metals poses significant threats to human health as they are associated with various developmental and chronic pathologies such as reproductive defects and cancers. Despite their profound risks, a comprehensive understanding of their disease-causing mechanisms is lacking. Most studies point to reactive oxygen species-induced DNA damage; however, their mutagenic potential is relatively weak suggesting the involvement of alternative mechanisms. One important, yet underexplored mechanism, is their ability to rewire the epigenome via DNA methylation and histone variant incorporation, leading to aberrant gene regulatory networks.

This study investigates the epigenetic mechanisms targeted by two ubiquitous heavy metals with …

Enhancing Translation: A Need To Leverage Complex Preclinical Models Of Addictive Drugs To Accelerate Substance Use Treatment Options, Christa Corley, Ashley Craig, Safiyah M. Sadek, Julie A. Marusich, Samar N. Chehimi, Ashley M. White, Lexi J. Holdiness, Benjamin C. Reiner, Cassandra D. Gipson

Markey Cancer Center Faculty Publications

Preclinical models of addictive drugs have been developed for decades to model aspects of the clinical experience in substance use disorders (SUDs). These include passive exposure as well as volitional intake models across addictive drugs and have been utilized to also measure withdrawal symptomatology and potential neuro- behavioral mechanisms underlying relapse to drug seeking or taking. There are a number of Food and Drug Administration (FDA)-approved medications for SUDs, however, many demonstrate low clinical efficacy as well as potential sex differences, and we also note gaps in the continuum of care for certain aspects of clinical ex- periences in individuals …

Quantum Dots' Toxicity: A Multi-Level Investigation On The Impact Of Quantum Dots On The Actin Cytoskeleton, Nhi Le

Graduate Theses/Dissertations

Quantum dots (QDs) are fluorescence nanomaterials with unique optical and physical properties. As such, they are highly sought after for their potential use in several biomedical and industrial applications. Despite their vast potential, recent studies have suggested that quantum dots are toxic to cells. Yet, the mechanism of quantum dots’ toxicity remains unclear. As such, my thesis aims to comprehensively examine the mechanism of quantum dots’ toxicity, emphasizing how quantum dots disrupt the actin cytoskeleton. In this study, I used RNA sequencing and mass spectrometry to investigate the influence of CdSe/ZnS QDs on the transcriptomic proteomic level of Saccharomyces cerevisiae …

Nanotoxicology Of Cdse/Zns Quantum Dot Alternatives In Thle-2 And Hepg2 Liver Cells, Seth Harris

Graduate Theses/Dissertations

Fluorescent nanoparticles known as quantum dots (QDs) have unique properties that make them useful in biomedicine. Specifically, CdSe/ZnS QDs, while good at fluorescing, show toxicity. Due to this, safer alternatives have been developed. This study uses an XTT viability assay, ROS fluorescent imaging, and apoptosis to investigate the effect of QD alternatives InP/ZnS, CuInS₂/ZnS, and carbon dots (NCD) in liver cells. The liver is a possible destination for accumulation of QDs making it an appropriate model for testing. A cancerous liver cell line known as HepG2, and an immortalized liver cell line known as THLE-2 were used. At …

Neurodevelopmental Vulnerability To Gestational Ozone Exposure, Vishnupriya Alavala, Sarah E. Brent, Christopher G. Canal, Joseph Wang, Russell P. Hunter, Matthew J. Campen, Andrew K. Ottens

Undergraduate Research Posters

Ambient air pollution accounts for about 4.2 million premature deaths annually per the World Health Organization. Ozone (O3) is a highly reactive air pollutant found in smog and is implicated in cellular damage leading to organ dysfunction. Ambient air pollution is associated with neurodevelopmental, behavioral, and cognitive disorders though ozone’s role is unknown. Studies here look at ozone exposure shortly after implantation vs. shortly before term to evaluate differences in neurodevelopmental susceptibility over time.

To inquire on the effects of ozone on the fetal brain, pregnant Sprague-Dawley rats were exposed once to 0.3 ppm of O3 or filtered air (FA) …

An Insight Into The Physicochemical, Drug-Likeness, Pharmacokinetics And Toxicity Profile Of Kigelia Africana (Lam) Bioactive Compounds, Sulyman Olalekan Ibrahim, Halimat Yusuf Lukman, Marili Funmilayo Zubair, Oluwagbemiga Tayo Amusan, Fatimah Ronke Abdulkadri, Bashir Lawal, Lateefat Bello Abdulfatah, Olubunmi Atolani

Al-Bahir

Kigelia africana plant is multipurpose plant whose therapeutic potential has been thoroughly investigated. The physicochemical, solubilities, ADMET, pharmacological, and drug-like properties of this plant have not been reported in details. This study makes use of the information that is currently known on the chemical make-up of the plant to forecast its overall toxicity as well as the potential for the phytochemicals it contains to be employed in medication discovery. The study also employed free web servers for the lipophilicity, water solubility, drug-likness, bioavailability score, medicinal chemistry and toxicological profiling of the compounds of K. africana. Artemether, a known antimalaria …

Epitranscriptomic Regulation In Breast Cancer And Pcb-Induced Liver Disease., Belinda Petri

Electronic Theses and Dissertations

Post-transcriptional RNA modifications including N6-methyladenosine (m6A) regulate mRNA stability, splicing, and translation. My research examined m6A in two disease models: breast cancer (BCa) and non-alcoholic fatty liver disease (NAFLD). Acquired resistance to endocrine therapies (ET) develops in approximately 20% of BCa patients with estrogen receptor α positive (ER+) tumors following treatment. The mechanisms by which tumor cells evade ET are not completely understood. Using a cell line model, we investigated the role of an m6A reader protein, HNRNPA2B1 (A2B1) that is upregulated in ET-resistant ER+ BCa cells. Stable overexpression of A2B1 in ET-sensitive MCF-7 cells (MCF-7-A2B1), results in ET resistance, …

Linking The Metabolic And Ecological Fate Of Caribbean Ciguatoxins And Related Neurotoxins In Reef Herbivores, Jessica K. Gwinn

Graduate Theses and Dissertations (2019 - present)

Ciguatera poisoning (CP) is one of the most prominent seafood-borne illnesses worldwide, affecting between 25,000–500,000 people annually. Ciguatera is caused by the ingestion of seafood contaminated with algal-derived ciguatoxins (CTX), the precursors of which are produced by benthic and toxigenic dinoflagellates in the genera Gambierdiscus and Fukuyoa. These compounds enter marine food webs through herbivory and are subsequently transferred to higher trophic levels, undergoing complex metabolic biotransformations, which produce structurally related CTX derivatives. Consumption of CTX induces a variety of severe neurological, gastrointestinal, and/or cardiovascular symptoms beginning within hours and lasting for weeks to months following exposure. Despite the impact …

Esterase Mediated Insecticide Resistance In The Southern House Mosquito, Culex Quinquefasciatus, Vivek Pokhrel

LSU Doctoral Dissertations

Much is known about the development of insecticide resistance associated with targeted application against insect populations. However, off-target selection by applications of insecticides in agricultural and residential sites also impacts development of insecticide resistance and is understudied. Similarly, the impact of selecting one life stage of mosquitoes on the insecticide susceptibility of different life stages is largely unknown. The first part of this study shows that susceptibility to chlorantraniliprole, which is applied in rice and sugarcane fields in LA, decreased (5.7 to12-fold) in populations of Culex quinquefasciatus collected from near these fields compared to a reference field strain. In addition, …

Floating Treatment Wetlands For Brackish Waters: Plant Selection And Nutrient Uptake Potential., Andrea Landaverde

All Theses

Brackish water bodies in coastal regions provide critical ecosystem services that support human and environmental health. Anthropogenic activities such as agricultural and industrial activities, construction, urban settlements, and tourism contribute to increased inputs of nitrogen (N) and phosphorus (P) in brackish coastal ecosystems. Excess nutrients can lead to impaired water quality and affect marine organisms. Floating treatment wetlands (FTWs) are a vegetated-base technology used to remove contaminants from water column, that has been mainly studied and applied in freshwater systems. Application of FTWs in brackish systems requires further investigation, as high salinity in brackish waters could result in toxicity to …

In Vitro Toxicological Evaluation Of Mesoporous Silica Microparticles Functionalised 1 With Carvacrol And Thymol, Cristina Fuentes, Ana Fuentes, Hugh Byrne, José Barat, María José Ruiz

Articles

The cytotoxicity of carvacrol- and thymol- functionalised mesoporous silica microparticles (MCM-41) was assessed in the human hepatocarcinoma cell line (HepG2). Cell viability, lactate dehydrogenase (LDH) activity, reactive oxygen species (ROS) production, mitochondrial membrane potential (ΔΨm), lipid peroxidation (LPO) and apoptosis/necrosis analysis were used as endpoints. Results showed that both materials induced cytotoxicity in a time and concentration-dependent manner, being more cytotoxic than free essential oil components and bare MCM-41. This effect was caused by the cell-particle interactions and not from degradation products released to the culture media, as demonstrated in the extract dilution assays. LDH release was seen to be …

The Role Of Dichloro(Ethylenediamine) Platinum Ii In Altering Cellular Iron And Copper Transport, Megan Hall

Mahurin Honors College Capstone Experience/Thesis Projects

Approximately 50% of all chemotherapy cancer patients receive a platinum chemotherapeutic during their treatment. Although these drugs are widely utilized, little is known about the cellular transport of platinum drugs. It is hypothesized that platinum utilizes transporters for other metals to enter the cell. Structural differences between compounds are predicted to affect the compounds’ ability to exploit different transporters. Also, different cell types express different transporters. Therefore, compound structure is expected to influence transport of platinum compounds differently in different cell types. This study investigated the role of the platinum drug cisplatin and platinum compound Pt(en)Cl₂ in altering iron …

Determining The Effects Of Chemical Exposure On Hepatocyte Mitochondrial Networks And Cell Viability, Bethany Eaton

All Master's Theses

Mitochondria are cellular organelles that are becoming more recently studied. One of their main functions is the production of energy through cellular respiration, which is crucial to cell life. However, they are also associated with numerous disease states. It is hypothesized that reactive oxygen species (ROS), largely produced in mitochondria, induce oxidative stress and affect mitochondrial morphology along with cell viability. This study compares chemical exposure of menadione, an ROS producer, and phthalates (plasticizers) on two mouse hepatocyte cell lines to determine the effects they have on mitochondrial morphology and cell viability. Three experiments were performed to analyze the effects …

Development And Validation Of A Method For The Determination Of Designer Benzodiazepines In Hair By Liquid Chromatography Tandem Mass Spectrometry (Lc-Ms/Ms), Laura C. Defreitas

Student Theses

In recent years, new designer benzodiazepines have become a challenge in forensic toxicology. These substances are analogues of the classic benzodiazepines, but their pharmacology is not well known, and many of them have been associated with overdoses and deaths. As a result, there has been a surge in efforts to develop ways to accurately test for these compounds in different biological matrices. This study focused to develop and validate a method for determining 17 new designer benzodiazepines in hair by liquid chromatography tandem mass spectrometry (LC-MS/MS). Hair samples were decontaminated, pulverized, and 20 mg of the sample was incubated in …

Cellular Toxicity Of Malonato (Ethylenediamine) Platinum (Ii) In Models Of Cancer, Sidikat Olanrewaju Olajuwon

Masters Theses & Specialist Projects

Platinum(II) compounds including the three FDA approved drugs, cisplatin, carboplatin, and oxaliplatin, are composed of two structural components, a leaving ligand, and a non-leaving ligand, each attached to a central platinum(II) atom. All bifunctional platinum compounds studied have similar mechanisms of initiating cell death. However, their efficacy as chemotherapeutics depends on the tissues in which the cancer originates. No model has explained these tissue-specific efficacies. We hypothesized that the efficacies of these platinum compounds vary due to structural differences in the leaving ligands. To test the influence of the leaving ligand on cellular survival, novel platinum compounds were synthesized, and …

Computational Analysis Of Type 3 Iodothyronine Deiodinase: Potential Inhibitors, Substrate Binding, And Dimer Structure, Eric Scott Marsan

Chemistry & Biochemistry Theses & Dissertations

Thyroid hormones (THs) in mammalian tissues are crucial for development and maintaining metabolic homeostasis. Iodothyronine deiodinases (Dios) remove iodines from THs by a selenocysteine (Sec) residue, which either activates or inactivates them. Halogen bonding (XB) has been proposed to describe the interaction between the Se and I atoms of the T4-Dio complex. Disruption of TH homeostasis by xenobiotics, such as polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) can cause deleterious effects on the endocrine system. Experimental studies have indicated that PBDEs and PCBs could disrupt TH homeostasis by inhibiting Dio through XB formation. However, no current quantitative study exists …

Pectin And Alginate Extraction To Treat Liquid Cafo Manure, Clare Sunderman

Honors Projects

For this project, various extraction methods were used to extract pectin from Pastinaca Sativa and alginate from Macrocystis. These extractions were then dried and used in treating 250mL of manure along with a CaCl₂ or FeCl₃ coagulant. It was found that CaCl₂ was not as effective as FeCl₃ in coagulating manure. But the results obtained suggest that pectin and alginate obtained with a simpler extraction method is just as effective as the highly purified and refined pectin and alginate produced for the food industry, in the treatment of CAFO manure. The liquid portion of the …

Regulation Of In Vitro And In Vivo Hepatic Stellate Cell Activation By The Ayrl Hydrocarbon Receptor, Shivakumar Rayavara Veerabhadraiah

Boise State University Theses and Dissertations

Liver fibrosis is a pathological condition characterized by the excessive deposition of extracellular matrix material by activated hepatic stellate cells (HSCs). We recently reported that activation of the aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor, with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) increases HSC activation in vitro and in mouse models of experimental liver fibrosis. The goal of this project was to determine the mechanism by which AhR activation impacts HSC activation and the subsequent development of liver fibrosis. It is possible that HSCs are direct cellular targets for TCDD. Alternatively, TCDD could increase HSC activation indirectly by exacerbating hepatocyte damage …

An Investigation Into The Adverse Effects Of Oxidative Stress From Exposure To Bisphenol A And Its Analogues, Rachel Nas

Senior Honors Theses

Oxidative stress is a physiological event caused by an overaccumulation of reactive oxygen species (ROS) within the body. While ROS are a natural by-product of oxygen metabolism, too many can lead to cell and tissue damage and contribute to many etiologies. Bisphenol A (BPA), a component of many plastic products, has been shown to induce oxidative stress. While the industrial usage of BPA usage has lessened, the safety of its replacements is unknown. This paper will primarily discuss ROS and mechanisms of oxidative stress, the usage of BPA and its analogues, etiologies associated with oxidative stress resulting from exposure to …