RESUMEN
Chemical regulatory authorities around the world require systemic toxicity data from acute exposures via the oral, dermal, and inhalation routes for human health risk assessment. To identify opportunities for regulatory uses of non-animal replacements for these tests, we reviewed acute systemic toxicity testing requirements for jurisdictions that participate in the International Cooperation on Alternative Test Methods (ICATM): Brazil, Canada, China, the European Union, Japan, South Korea, Taiwan, and the USA. The chemical sectors included in our review of each jurisdiction were cosmetics, consumer products, industrial chemicals, pharmaceuticals, medical devices, and pesticides. We found acute systemic toxicity data were most often required for hazard assessment, classification, and labeling, and to a lesser extent quantitative risk assessment. Where animal methods were required, animal reduction methods were typically recommended. For many jurisdictions and chemical sectors, non-animal alternatives are not accepted, but several jurisdictions provide guidance to support the use of test waivers to reduce animal use for specific applications. An understanding of international regulatory requirements for acute systemic toxicity testing will inform ICATM's strategy for the development, acceptance, and implementation of non-animal alternatives to assess the health hazards and risks associated with acute toxicity.
RESUMEN
Globally, industries and regulatory authorities are faced with an urgent need to assess the potential adverse effects of chemicals more efficiently by embracing new approach methodologies (NAMs). NAMs include cell and tissue methods (in vitro), structure-based/toxicokinetic models (in silico), methods that assess toxicant interactions with biological macromolecules (in chemico), and alternative models. Increasing knowledge on chemical toxicokinetics (what the body does with chemicals) and toxicodynamics (what the chemicals do with the body) obtained from in silico and in vitro systems continues to provide opportunities for modernizing chemical risk assessments. However, directly leveraging in vitro and in silico data for derivation of human health-based reference values has not received regulatory acceptance due to uncertainties in extrapolating NAM results to human populations, including metabolism, complex biological pathways, multiple exposures, interindividual susceptibility and vulnerable populations. The objective of this article is to provide a standardized pragmatic framework that applies integrated approaches with a focus on quantitative in vitro to in vivo extrapolation (QIVIVE) to extrapolate in vitro cellular exposures to human equivalent doses from which human reference values can be derived. The proposed framework intends to systematically account for the complexities in extrapolation and data interpretation to support sound human health safety decisions in diverse industrial sectors (food systems, cosmetics, industrial chemicals, pharmaceuticals etc.). Case studies of chemical entities, using new and existing data, are presented to demonstrate the utility of the proposed framework while highlighting potential sources of human population bias and uncertainty, and the importance of Good Method and Reporting Practices.
RESUMEN
We hypothesized that a digestion-resistant maltodextrin, Fibersol-2 (Archer Daniels Midland/Matsutani LLC, Decatur, IL, USA) may impact satiety by decreasing hunger, prolonging satiation, and/or increasing peripheral satiety signals. In a randomized, double-blind, placebo-controlled crossover study, healthy subjects (9 men and 10 women) underwent 3 treatments in which they consumed a standardized meal with a tea containing 0, 5, or 10 g of Fibersol-2. A visual analog scale questionnaire was given in 30-minute intervals to measure subjective appetite and satiety. Blood was drawn just before the meal (time 0) and at 30, 60, 90, 120, 180, and 240 minutes after meal for measurements of plasma ghrelin, cholecystokinin, gastrin, peptide YY, gastric inhibitory polypeptide, and glucagon-like peptide-1, all by enzyme-linked immunosorbent assay. There were significant delays in hunger and increased satiety for 1.5 to 2 hours after treatment with 10 g of Fibersol-2. These delays did not occur after ingesting 0 or 5 g Fibersol-2 at any time. Control and 5 g Fibersol-2 treatments did not suppress increases in hunger postmeal; hunger scores increased and satiety scores decreased significantly (P < .05) at all time points relative to the first postmeal assessment. Plasma peptide YY and glucagon-like peptide-1 were significantly increased by the ingestion of meal with tea containing 10 g Fibersol-2 compared with 0 or 5 g Fibersol-2 (P < .05). This study demonstrated that 10 g Fibersol-2 with a meal stimulated production of satiety hormones and enhanced satiety.