A toxin called euglenophycin is a well documented fish killer, but years after that fact was revealed researchers have now discovered that it also has the potential to be an effective cancer treatment as well.

Back in 2002 a fish farm in South Carolina was hit by a rash of mysterious deaths amongst the fish in their farm ponds.  In just eight weeks that summer more than 21,000 striped bass died, resulting in a $100,000 loss for the company.

In attempt to help the baffled but worried fish farmers discover the reason for the sudden rise in the mortality rate amongst their fish, Agricultural Research Service microbiologist Paul V. Zimba and chemist Peter Moeller of the U.S. National Oceanic and Atmospheric Administration, working in conjunction with a University of Michigan biologist Richard Triemer began testing various water samples from the “deadly” ponds and the algae and bacteria they contained.

In a 2004 summary paper the researchers lay out their findings; the murderous culprits were identified as Euglena sanguinea and E. granulate, known species of freshwater algae that had been considered totally harmless in the past.

Although this was the first documentation of a killer strain of freshwater algae it was not the last. The team subsequently documented 11 more cases worldwide, affecting not only striped bass but also tilapia and channel catfish. The financial impact on the fishing industry was estimated to be in excess of $1 million.

Peter Moeller later began purifying the active components of the toxic algae and was able to define the characteristics of the molecular structure of it. The toxin is now known as euglenophycin and its fish killing powers have been demonstrated in the laboratory. When exposed to a purified form of the murderous toxin, a catfish lifespan is reduced to four hours.

But what does this all have to do with cancer cells? The scientists who discovered the toxin have applied for a patent protection for it, and its possible uses are now being investigated. And one such use may be the destructions of cancer cells.

Early laboratory tests have shown that the use of fairly low concentrations of euglenophycin actually led to a significant decrease in overall cancer cell growth, and indeed killed some outright. Future testing is planned to determine if the toxin can have the same or a similar effect against cancer tumors themselves. Positive results could have huge implications for future cancer treatments, and would mean that all those bass would not have died in vain.