Red Tide Toxin Metabolite Accumulates in Organs, May Pose Greater Risk to Shellfish Consumers
In 2012, the state of Texas experienced the longest red tide on record, leading to a collapse of its oyster industry.
Red tides in the Gulf of Mexico affect humans, wildlife, fisheries, and the regional tourist-related economy. They are caused by the harmful algae Karenia brevis, which release a neurotoxin called brevetoxin that accumulates in exposed shellfish and leads to neurotoxic shellfish poisoning (NSP).
Research shows that brevetoxin is highly reactive and attaches to other molecules, leading to hybrid “conjugate” molecules that often escape existing detection methods. Simple addition of a lipid causes brevetoxin to accumulate in internal organs, circulate longer in the blood, and increase its potency on nerve cells—all factors posing a greater risk to shellfish consumers.
A new study published in the American Chemical Society journal: Chemical Research in Toxicology shows that a lipid metabolite of the red tide toxin brevetoxin formed in contaminated oysters, N-palmidoyl-S-desoxy-BTX-B2, concentrates in internal organs like the spleen, liver, and lung of exposed laboratory mice. The study reveals that these types of changes to the toxin molecule may increase or decrease accumulation in internal organs and tissues. Accumulation of toxin may prolong the effects and change the outcome of NSP.
Expanding the knowledge of the toxic properties of brevetoxins will help refine strategies to mitigate risk to shellfish consumers, improve resiliency of local fishing industries, and control negative economic impacts.
For additional information, contact John.Ramsdell@noaa.gov.