While researching the potentially lethal toxins of a species of cone snail, scientists discovered that these toxins possess pain-relieving properties. Many other toxins from marine snails have also been used to treat dangerous conditions such as cardiovascular diseases and Parkinson’s disease.
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Cone snail |
Chronic pain sufferers, such as cancer patients or those with amputations, often find that conventional painkillers are ineffective and may rely on morphine—a derivative of opium. Long-term use of morphine can lead to addiction, requiring higher doses over time, and eventually necessitating slow infusion to maintain a constant level in the blood. Currently, nearly 50,000 people in the United States require such infusions, and many of them continue to suffer from pain. However, there is now a drug called Prialt, which is 50 times more potent than morphine and is administered via a pump. Prialt is a synthetic drug modeled after the toxin of the cone snail. The journey from the cone snail to Prialt is quite fascinating.
The story began over twenty years ago when a young, impoverished Filipino researcher named Olivera needed to undertake a research project that wouldn’t cost much. As a child, he enjoyed exploring coral reefs to collect cone snails, which are renowned for their beautiful and valuable shells. Olivera knew that these snails could inject venom for self-defense, and being stung could cause total body paralysis, posing a serious threat to life. In 1980, Olivera identified the toxin from the cone snail, marking the beginning of the research that would lead to the development of Prialt. Today, Olivera is a professor of biology at the University of Utah in Salt Lake City.
While studying the effects of conotoxin from the cone snail on the central nervous system, researchers accidentally discovered its analgesic properties. When nerve signals travel up the spinal cord to the brain, calcium ions must move across the cell membrane. This pathway for calcium ions is known as the “calcium channel.” The cone snail toxin blocks the passage of calcium through the cell membrane, acting as a “calcium channel blocker.” This blocking ability is very precise, preventing pain signals from reaching the brain. The nervous system continues to function normally, eliminating the side effects associated with morphine-based painkillers.
Currently, another toxin from the cone snail, which has neuroprotective properties, is being tested with hopes of using it for patients suffering from epilepsy. Additionally, various toxins from different types of marine snails are being researched for treating heart diseases, vascular conditions, and Parkinson’s disease.
The Ocean, an Abundant Source of Pharmaceuticals
In 1928, British scientist Alexander Fleming accidentally discovered the antibacterial properties of a mold called Penicillium notatum, leading to the development of the first antibiotic. Following this, there was a rush to excavate everything from riverbank mud to dense forests to discover new medicines! Beyond antibiotics, nearly half of all current medications originate from natural environmental sources. However, as the saying goes, “there’s only so much to be dug up.”
As a result, attention began to shift towards the oceans. The vast oceans cover three-quarters of the Earth’s surface. For millions of years, countless small creatures have thrived in an environment where “the strong eat the weak, and the big fish eat the small fish.” Many organisms can secrete substances for defense against predators, even though these secretions may be heavily diluted in seawater. Additionally, marine plants like algae also produce compounds with medicinal properties. Numerous projects are currently underway to test potential medicines derived from marine organisms, with promising applications for treating cancer, infections, asthma, and skin diseases.
One type of microscopic animal that clings to rocks or the bottoms of boats is collectively known as bryozoa. Each bryozoan resembles a soft corn kernel and possesses both male and female reproductive organs to produce sperm and eggs, growing similarly to plants. Within these bryozoa are bacteria that can be used to create a compound known as bryostatin. This compound, when combined with cancer treatments such as cisplatin and Taxol, has shown significantly improved results. Bryostatin has also been used to treat leukemia. However, producing bryostatin requires a massive amount of bryozoa; it is estimated that 14 tons of bryozoa yield only 18 grams of bryostatin! Pharmacologists are working towards synthesizing this compound.
Another example is a medication derived from a type of sponge that effectively treats asthma, matching the potency of strong drugs like steroids without the side effects. Additionally, the anti-inflammatory compound pseudopterosin, derived from a plant that grows on Caribbean coral, has been incorporated into sunscreen products by companies like Estee Lauder for over a decade.
The field of Marine Pharmacology, which studies pharmaceuticals derived from the sea, is gaining increasing significance. A few decades ago, it was merely a niche area of research for scientists working quietly in laboratories. Now, major pharmaceutical companies like Aventis, Johnson & Johnson, and Novartis are actively engaged in this field. Each year, a wide variety of potentially pharmacologically active compounds derived from the ocean are compiled. For instance, in 1999, a report from Midwestern University indicated that research yielded compounds from marine sources that included:
– 21 compounds with anti-parasitic, antibacterial, antifungal, and anti-malarial properties, as well as effects on blood clotting similar to aspirin, tuberculosis, and viruses.
– 23 compounds impacting cardiovascular health, the nervous system, inflammation, and immunity.
– 22 compounds with various other effects.
