- Jaejeong & Jaeah Kim
Coral Reefs: Underwater Pharmacies
(Scientist Studying a Coral Reef)
We recently posted a coral dissection video (which you can check out here), where we explained the anatomy and physiology of these fascinating marine invertebrates. Unfortunately, as we mentioned in the video, coral reefs are in great danger due to climate change. Although you may be wondering why you should care about the destruction of coral reefs, did you know that aside from harboring the world’s most diverse ecosystem, providing clean water to the oceans, and providing millions of dollar to the fishing and touring industry, coral reefs also provide us with valuable chemical compounds that can be used for the development of new medicines? Coral reefs are often hailed to as a source for potential miracle drugs, and this is not a overstatement, considering how scientists have discovered more than 20,000 chemicals in coral reefs (and this list is growing by 1,000 chemicals a year) that have a potential use as pharmaceuticals against diseases ranging from cancer to HIV to Alzheimers.
So why are coral reefs so rich in new chemical compounds and potential pharmaceuticals? Turns out it’s a means of self defense. There are a lot of threats to any organism living in the wild, but this treat is especially great for sessile –meaning that the animal cannot move or can only move very slowly– organisms such as coral polyps. While fish, octopuses, crustaceans, and many land mammals can simply swim or run away from predators, that is not the case for coral polyps. Therefore, corals had to resort to a completely different method of self defense against diseases, parasites, predators, and other external threats. Although obvious defensive measures like spikes, exoskeletons, and shells are great, coral polyps decided to do one better and turned to chemical weapons as their primary means of protection. This is why coral reefs are such treasure chests of interesting chemical compounds that often prove to be invaluable pharmaceuticals.
Although most chemical compounds extracted from corals are still undergoing the process of determining its composition and possible uses, there are many more that are currently being used as pharmaceuticals against countless human diseases. Just a few examples would be a biofilm extracted from carribean corals that is used to treat bacterial infections, Dolastin 10 (drug extracted from Indian Ocean sea hare corals) that is used in various cancers, arabinosides (drug extracted from soft coral) that is used to fight HIV, and Secosteroids (enzyme extracted from Bahamian soft coral) that is used to treat arthritis, asthma, and other inflammatory diseases. Due to the permeability of coral, lab grown corals have also been used as bone grafts since the 1970s. In addition, it is important to note that chemicals extracted from corals have applications beyond pharmaceutics– in the cosmetics industry, sunscreens are being made of UV protecting compounds in coral, and makeup is made from white coral powders.
However, there are downsides to using corals in pharmaceutical applications. Coral reefs are already in big trouble due to climate change induced coral bleaching, pollution, and habitat loss– the last thing they need is the pharmaceutical industry coming in and overharvesting. Because of this, scientists are currently looking into methods of raising corals in labs, or even better, methods of synthesizing the chemicals found in corals from scratch with readily available substances.
If you want to learn more about how to help these fascinating organisms that are doing so much for us, check out our coral anatomy video (here).