Article ID Journal Published Year Pages File Type
4545368 Harmful Algae 2014 5 Pages PDF
Abstract

•We investigated the intestinal absorption of two common brevetoxin shellfish metabolites.•Caco-2 monolayers were utilized as an in vitro test to quantify permeability.•Dihydrobrevetoxin B rapidly and efficiently transfers across intestinal epithelium.•Cysteine brevetoxin B failed to transfer across intestinal epithelium.•Cysteine brevetoxin B persists in shellfish, but may not contribute to neurotoxic shellfish poisoning.

Brevetoxin B is a highly reactive molecule, due in part to an α,β-unsaturated aldehyde group at the terminal side chain, leading to metabolism by reduction, oxidation and conjugation. These reactions have little effect to reduce intrinsic activity at the voltage-gated sodium channel or during toxicity testing by either enzyme-linked immunosorbent assay or mouse bioassay. Here we investigate the potential for intestinal absorption of the two most abundant brevetoxins present in Gulf of Mexico oysters using human Caco-2 cell monolayers, a widely utilized in vitro test to predict oral bioavailability of drugs and their metabolites. We found that both dihydrobrevetoxin B and cysteine brevetoxin B were rapidly taken up by the Caco-2 monolayer. However, only dihydrobrevetoxin B passes through the monolayer to reach the basal compartment. Dihydrobrevetoxin B has a moderate apparent permeability coefficient of 1.6 × 10−6 cm/s at 500 ng/mL and nearly 50% of the toxin passes from the apical to basal compartment in 24 h. The inability of the cysteine brevetoxin B to pass through an intestinal epithelial barrier suggests that this bioactive brevetoxin metabolite that persists in shellfish may not contribute to neurotoxic shellfish poisoning.

Related Topics
Life Sciences Agricultural and Biological Sciences Aquatic Science
Authors
, , , , , ,