Development Features on the Selection of Animal Models for Teratogenic Testing

Study of acute lethality, teratogenesis, and metabolomic changes of N-(2'-hydroxyphenyl)-2-propylpentanamide (HO-AAVPA) on Artemia franciscana

The brine shrimp lethality test (Artemia spp.) is a classical model for assessing the toxicity of bioactive compounds. This study evaluated the toxicity and metabolomic changes induced by N-(2'- hydroxyphenyl)-2-propylpentanamide (HO-AAVPA), a derivative of valproic acid (VPA), in Artemia franciscana larvae using untargeted metabolomics through liquid chromatography-mass spectrometry (LC-MS/MS). The lethal concentration 50 (LC50) was determined by acute toxicity tests at 24 and 48 h, and teratogenic effects were assessed by measuring the larvae body length. Larval metabolomic changes were examined following 24- and 48-hour exposures to sublethal concentrations of HO-AAVPA (LC1 = 0.04 mM, LC10 = 0.2 mM) and VPA (LC1 = 1.79 mM, LC10 = 8.95 mM). After 48 h, HO-AAVPA had an LC50 of 0.32 mM, while VPA had 18.7 mM. VPA induced teratogenic effects at 9.6 mM; in contrast, HO-AAVPA only significantly affected the body length at 0.56 mM. Metabolomic analysis revealed that sublethal concentrations of HO-AAVPA affected the sphingolipid and glycerophospholipid metabolism, while VPA impacted alanine, aspartate, and glutamate metabolism. These findings suggest HO-AAVPA has high toxicity, but lower teratogenicity compared to VPA. In conclusion, the present study indicates that alterations in lipid and amino acid metabolism could be critical points in the mode of action of these compounds in A. franciscana.

Nanoparticle-Mediated Embryotoxicity: Mechanisms of Chemical Toxicity and Implications for Biological Development

Nanoparticles, defined by their nanoscale dimensions and unique physicochemical properties, are widely utilized in healthcare, electronics, environmental sciences, and consumer products. However, increasing evidence of their potential embryotoxic effects during pregnancy underscores the need for a molecular-level understanding of their interactions during embryonic development. Nanoparticles such as titanium dioxide, silver, cerium oxide, copper oxide, and quantum dots can cross the placental barrier and interfere with crucial developmental processes. At the molecular level, they disrupt signaling pathways like Wnt and Hedgehog, induce oxidative stress and inflammation, and cause genotoxic effects, all critical during sensitive phases, such as organogenesis. Furthermore, these nanoparticles interact directly with cellular components, including DNA, proteins, and lipids, impairing cellular function and viability. Innovative strategies to mitigate nanoparticle toxicity, such as surface modifications and incorporation of biocompatible coatings, are discussed as potential solutions to reduce adverse molecular interactions. Various laboratory animal models used to investigate nanoparticle-induced embryotoxicity are evaluated for their efficacy and limitations, providing insights into their applicability for understanding these effects. This Account examines the molecular mechanisms by which nanoparticles compromise embryonic development and emphasizes the importance of designing safer nanoparticles to minimize maternal-fetal exposure risks, particularly in biomedical applications.

An oral developmental toxicity study of generic pesticide pinoxaden in rabbits

The safety assessment of pinoxaden by the Joint Meeting on Pesticide Residues (JMPR) established a NOAEL of 30 mg/kg bw/day for maternal and embryo/fetal toxicity from a rabbit developmental toxicity study. However, the Pesticide Peer Review Expert meeting (EFSA) lowered the NOAEL to 10 mg/kg bw/day due to observed diaphragm malformations in one developmental toxicity study in rabbits, proposing a classification for developmental effects as Category 2 R63 or H361d. Both JMPR and EFSA set the Acceptable Daily Intake (ADI) at 0.1 mg/kg bw/day, derived from a 2-year rat study NOAEL with a safety factor of 100, but EFSA also supported ADI by teratology study in rabbits. The current prenatal developmental toxicity study on pinoxaden aimed to elucidate and clarify the potential teratogenic effects and could provide supplementary data for determining the ADI for pinoxaden. The study design exceeded the OECD TG 414 by including an assessment of internal organs. The test item was orally administered by gavage daily from day 6 to day 28 of gestation to three groups of animals, each composed of 21 females, in dose levels of 0, 10 and 30 mg/kg/bw/day. One female from the 30 mg/kg/bw/day dose group was euthanized in extremis on Day 27 post-coitum due to premature delivery, likely induced by poor general condition and was therefore considered to be an indirect effect of the test item. One female at 30 mg/kg/bw/day had entirely dead litters except for one live male pup (9 non-live implants vs 1 live fetus). Since the incidence of post-implantation loss or mean number of the dead pups within the remaining dams at 30 mg/kg/ bw/day that survived to necropsy was not significantly increased, we assume that the toxic effect was on the dam, rather than on the conceptus. No pinoxaden-related skeletal or visceral variations or malformations were observed. No evidence of developmental toxicity was observed. Under the conditions of the study, the pinoxaden produced maternal toxicity at a high dose tested; thus, NOAEL for maternal toxicity was determined to be 10 mg/kg bw/day. NOAEL for developmental toxicity was established at 30 mg/kg bw/day. The obtained results may supplement the overall safety and toxicity profile of pinoxaden. Nevertheless, the NOAEL determined in this study does not affect the previously established ADI.