Cyanobacteria (dark shades) found in Hawaii produce chemical compounds with biomedical potential. Image: Jennifer Smith
A seaweed considered a threat to the healthy growth of coral
reefs in Hawaii may possess the ability to
produce substances that could one day treat human diseases, a new study led by
scientists at Scripps Institution of Oceanography at University
of California, San Diego has revealed.
An analysis led by Hyukjae Choi, a postdoctoral researcher
in William Gerwick’s laboratory at Scripps, has shown that the seaweed, a tiny
photosynthetic organism known as a “cyanobacterium,” produces chemical
compounds that exhibit promise as anti-inflammatory agents and in combating
bacterial infections. The study is published Chemistry & Biology.
“In different arenas these compounds could be helpful, such
as treating chronic inflammatory conditions for which we currently don’t have
really good medicines,” said Gerwick, a professor of oceanography and
pharmaceutical sciences at the Center for Marine Biotechnology and Biomedicine
at Scripps and UC San Diego Skaggs School of Pharmacy and Pharmaceutical
Scientists identified the “nuisance” organism in 2008 on the
reefs directly adjacent to the National Park Pu‘uhonua o H’onaunau off the Kona
coast of Hawaii.
The cyanobacterium is believed to be native to Hawaii
and is usually inconspicuous, said Jennifer Smith, a Scripps assistant
professor in the Scripps
Center for Marine
Biodiversity and Conservation and a paper coauthor.
“When we first found the bloom during routine surveys with
the University of Hawaii we were concerned as it was clearly smothering
the corals at one of the most popular dive sites in Hawaii,” said Smith. “Observations in the
field even suggested that the cyanobacteria may have been releasing some
chemical that was causing the coral to bleach.”
When Smith and her colleagues found the seaweed blooming it
was clear that it was overgrowing and negatively affecting the underlying
corals. Samples were retrieved in 2009 and transferred to Scripps for analysis.
Choi, Gerwick, and their colleagues conducted various
laboratory experiments and discovered that the seaweed (the cyanobacterium Leptolyngbya crossbyana) generates
natural products known as honaucins with potent anti-inflammation and
Specifically, the substances hamper bacteria’s ability to “swarm” over surfaces. For example, when overtaking a new area, bacteria
secrete small amounts of a substance known as a quorum sensing factor, which
tests to see if the new surface is safe for colonization. Halting a quorum
sensing factor could one day translate to a treatment for bacterial infections.
For instance, this could be critical, Gerwick said, in the development of drugs
to prevent infection in patients who require catheters to deliver vital
nutrients to key areas such as arteries, as well the development of new
treatments for acne and other skin conditions.
“I think this finding is a nice illustration of how we need
to look more deeply in our environment because even nuisance pests, as it turns
out, are not just pests,” said Gerwick. “It’s a long road to go from this
early-stage discovery to application in the clinic but it’s the only road if we
want new and more efficacious medicines.”
“These organisms have been on the planet for millions of
years and so it is not surprising that they have evolved numerous strategies
for competing with neighboring species, including chemical warfare,” said
Smith. “Several species of cyanobacteria and algae are known to produce novel
compounds, many that have promising use in drug development for human and other