NCTR Division of Biochemical Toxicology Also referred to as: DBT

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Division Director: Frederick A. Beland, Ph.D.
Deputy Director: Luísa Camacho, Ph.D.

Meet the Principal Investigators — Biochemical Toxicology

About the Division

Mission

Conduct fundamental and applied research designed to define the biological mechanisms of action underlying the toxicity of FDA-regulated products, as well as characterize the carcinogenic risks associated with chemicals of interest to the FDA.

Strategies

Conduct bioassays, mechanistic studies, and computational modeling.

Metrics

Provide reports to FDA Product Centers and funding agencies and publish manuscripts. 

Bisphenol A: Toxicology and Pharmacokenetic Data to Inform Ongoing Safety Assessments
Presented by K. Barry Delclos, Ph.D.

Watch the Recorded Presentation

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2022 Select Accomplishments

Male Reproductive Toxicities Induced by Cannabidiol and Its Main Metabolites in Vitro

Researchers at NCTR, in collaboration with scientists from the Center for Food Safety and Applied Nutrition, investigated potential male reproductive toxicities and their underlying mechanisms induced by cannabidiol (CBD) and its main metabolites — 7-carboxy-CBD and 7-hydroxy-CBD — using immortalized mouse Sertoli cells and primary human Sertoli cells. Study results showed that CBD and its main metabolites can inhibit cellular proliferation in mouse and human Sertoli cells. The molecular mechanisms underlying CBD-induced cytotoxicity in primary human Sertoli cells were investigated further using a transcriptomic approach with mRNA sequencing analysis. The results showed that CBD exposure mainly disturbs DNA replication, cell cycle, and DNA repair signaling pathways and induces cellular senescence in primary human Sertoli cells. These findings will help the FDA better define safety concerns regarding CBD. (Food and Chemical Toxicology)

Toxicological Evaluation of Brominated Vegetable Oil in Sprague-Dawley Rats 

Researchers from NCTR, in collaboration with scientists from the Center for Food Safety and Applied Nutrition, investigated the potential toxicities from ingesting the food additive brominated vegetable oil (BVO) using a rat model. Study findings expanded upon previous observations in rats and pigs that oral exposure to BVO is associated with increased tissue levels of inorganic and organic bromine and that the thyroid is a potential target organ of toxicity. This research and its findings will help the FDA better define safety concerns regarding BVO. A paper reporting the study findings was published in Food and Chemical Toxicology.

Temporal Dynamics of SARS-CoV-2 in Wastewater Influent

NCTR scientists, in collaboration with the Arkansas Department of Health and the University of Arkansas for Medical Sciences, developed a method to monitor the presence of SARS-CoV-2 and its genetic variants in local community wastewater in Little Rock and Pine Bluff, Arkansas. Using this method, researchers were able to identify the SARS-CoV-2 variants (e.g., Delta, Omicron) in the wastewater that were responsible for epidemic outbreaks. The viral titers found in the wastewater correlated with the number of COVID-19 clinical cases. These findings support the use of wastewater surveillance as a reliable complementary tool for monitoring SARS-CoV-2 and its genetic variants at the community level and can serve as an early indicator of viral spread and new variants. The study findings were published in Science of The Total Environment. 

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2023 Select Research Projects

• Assess the developmental reproductive toxicity of metformin and glyburide

• Assess the epigenetic effects of the human food additive food-grade titanium dioxide in vitro

• Determine sex differences in immune responses to nanoparticles in vitro

• Develop an artificially intelligent virtual pregnant woman modeling suite to support regulatory decisions

• Develop a first-generation in-house FDA pregnancy PBPK model-based tool to enhance the safety and efficacy of therapeutic agents in the perinatal period

• Evaluate the fetal and neonatal toxicokinetics of C6-fluorotelomer alcohol

• Analyze SARS-CoV-2 antibodies in human plasma using flow cytometry

• Identify genomic and genetic determinants of the susceptibility to non-alcoholic fatty liver disease (NAFLD) and NAFLD-related liver cancer

• Conduct high-throughput functional screens and mechanistic analysis of microRNAs that regulate chemotherapeutic resistance in ovarian cancer

• Evaluate the percutaneous absorption of the cosmetic contaminant 1,4-dioxane

• Evaluate the percutaneous absorption of the sunscreen component avobenzone

• Assess the performance of 3D-bioprinted human skin equivalents for in vitro dermal absorption testing of FDA-regulated drugs and cosmetic ingredients used for dermal and transdermal applications

• Evaluate the pharmacokinetics of nicotine in Sprague-Dawley rats

• Evaluate the pharmacokinetics of cannabidiol and its major metabolites in pregnant Sprague-Dawley rats and their pups exposed orally to cannabidiol

• Evaluate the pharmacokinetics of cannabidiol upon dermal exposure in Sprague-Dawley rats

• Study the relationship between liver epigenomic phenotype and susceptibility to non-alcoholic steatohepatitis

• Evaluate the selection of complex mixtures for toxicological assessments

• Surveil SARS-CoV-2 in wastewater as a complementary tool to estimate the viral spread in Arkansas

• Stimulate innovation in clinical evaluations and personalized medicine to improve patient outcomes with triple negative breast cancer

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Resources for You

• DBT Fact Sheet
• NCTR Grand Rounds: "Bisphenol A: Toxicology and Pharmacokenetic Data to Inform Ongoing Safety Assessments (Presentation recorded in Adobe Connect on September 13, 2018)
• Annual Reports
• Meet the Principal Investigators

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