Investigators at NOAA’s National Ocean Service have observed that a commonly used cholesterol-lowering drug provides protective effects to a toxin produced by microscopic marine algae. Drs. J.S. Ramsdell, R. Woofter, J. Colman, S. Dover and M.Y. Dechraoui Bottein. National Oceanic Atmospheric Administration. Charleston, S.C., describe their research at an American Society for Pharmacology & Experimental Therapeutics session at the Experimental Biology 2003 meeting in San Diego.
Blooms of these toxic marine algae, commonly called harmful algal blooms (HABs) are one of the most scientifically complex and economically significant coastal issues facing the nation today. In the past, only a few regions of the U.S. were affected by HABs, but now virtually every coastal state has reported major blooms.
Economic losses associated with HABs may exceed $1 billion over the next several decades. HABs have direct and indirect impacts on fisheries resources, local coastal economies, as well as public health and perception. HABs can cause human illness and death, alter marine habitats, adversely impact fish and other marine organisms, as well as close many coastal businesses.
HABs produce some of the most potent toxins known to man. These toxins are primarily neurotoxins, causing symptoms ranging from numbness and tingling sensations to memory impairment to respiratory paralysis. At present, coastal areas with persistent HAB problems are monitored for toxic algae in coordination with testing of seafood products. In the near future, forecasting of harmful algal blooms and new biomonitoring and therapeutic methods are anticipated to provide advanced warning capabilities, diagnostics and treatments.
Cholestyramine, a commonly used cholesterol-lowering drug retained in the digestive tract, blocks re-absorption of cholesterol and related molecules. Cholestyramine is reported to provide protective effects following exposure of laboratory rats to fungal toxins and more recently to reduce the symptoms of certain toxic disorders in humans.
In this study, dietary cholestyramine was found to reduce the toxic effects of the algal toxin brevetoxin, in mice.
This therapeutic approach, if proven successful could be anticipated to have the most beneficial outcome to people suffering from ciguatera fish poisoning, a chronic neurotoxic disease resulting from consumption of coral reef fish contaminated with ciguatoxin (a toxin very closely related to the brevetoxin used in this study).
Ciguatera, occurs in tropical and subtropical regions worldwide and within the U.S. (South Florida, Hawaii, Caribbean and Pacific territories) and estimated to afflict 177,255 people from 1987-92 at an economic impact of $138 million. Because of the long duration of the symptoms, therapeutic methods are in great demand. These NOAA researchers are concurrently developing a blood detection method to confirm toxin exposure prior to treatment. This research is supported by the National Oceanic and Atmospheric Administration.
(American Society for Pharmacology and Experimental Therapeutics)