Related Experiment Video
Updated: Feb 23, 2026

Measuring the Effects of Bacteria and Chemicals on the Intestinal Permeability of Caenorhabditis elegans
Published on: December 3, 2019
Absorption and Effect of Azaspiracid-1 Over the Human Intestinal Barrier
Paula Abal1, M Carmen Louzao1, María Fraga1
1Departamento de Farmacología, Facultad de Veterinaria, Universidad de Santiago de Compostela, Lugo, Spain.
Background:
Azaspiracids (AZAs) are marine biotoxins produced by the dinoflagellates genera Azadinium and Amphidoma. These toxins cause azaspiracid poisoning (AZP), characterized by severe gastrointestinal illness in humans after the consumption of bivalve molluscs contaminated with AZAs. The main aim of the present study was to examine the consequences of human exposure to AZA1 by the study of absorption and effects of the toxin on Caco-2 cells, a reliable model of the human intestine.
Methods:
The ability of AZA1 to cross the human intestinal epithelium has been evaluated by the Caco-2 transepithelial permeability assay. The toxin has been detected and quantified using a microsphere-based immunoassay. Cell alterations and ultrastructural effects has been observed with confocal and transmission electron microscopy Results: AZA1 was absorbed by Caco-2 cells in a dose-dependent way without affecting cell viability. However, modifications on occludin distribution detected by confocal microscopy imaging indicated a possible monolayer integrity disruption. Nevertheless, transmission electron microscopy imaging revealed ultrastructural damages at the nucleus and mitochondria with autophagosomes in the cytoplasm, however, tight junctions and microvilli remained unaffected.
Conclusion:
After the ingestion of molluscs with the AZA1, the toxin will be transported through the human intestinal barrier to blood causing damage on epithelial cells.
More Related Videos
Related Concept Videos
Drug Absorption: Factors Affecting GI Absorption
Factors Affecting Dissolution: Drug Permeability, Stability and Stereochemistry
Methods for Studying Drug Absorption: In vitro
The diffusion cell method uses a two-compartment cell, including a donor compartment with the drug solution, which simulates the environment where the drug is applied, and a receptor compartment with a buffer solution, which simulates the environment...
Bioavailability Enhancement: Drug Permeability Enhancement
Drugs for Treatment of Ulcerative Colitis in IBD
Factors Influencing Drug Absorption: Anatomical Parameters

