Natural or traditional medicine usually isn't the strongest option when combating a disease. However, studying traditional herbs and other natural products can be an excellent starting point for modern medicine. Sometimes the source isn't so obvious though, as many of our antibiotics come from fungus, bacteria, and other microbes.
What scientists are discovering is that these naturally occurring compounds can act more subtly than many of our older medications. Things like broad-spectrum antibiotics are quickly falling out of favor, because they encourage microbes to evolve immunity and interfere with our bodies beneficial microbes. But for every precision tool, nature also produces the occasional blunt instrument, as is the case with borrelidin.
Borrelidin was originally isolated from a particular bacterial species, now a team from the Scripps Research Institute are taking a closer look. (via EurekaAlert) It's of great interest because it's a tRNA synthesis inhibitor. Transfer RNA is an essential structure in protein synthesis. When a protein is being synthesized, the ribosome translates the messenger RNA into an amino acid chain. It can do this because tRNA structures link amino acid building blocks with corresponding code in the messenger RNA.
So interfering with the production of tRNA quickly interferes with proteins synthesis as a whole, eventually shutting down an organism. Previous work on borrelidin showed that it also specifically interfered with the development of new blood vessels in animals. This could have major implications for cancer research, as limiting blood vessel growth could cut off a tumor's nutrient supply.
Different compounds in the same class of inhibitors have already shown effective in some cases. One is already an approved topical treatment for bacterial skin infections, and another has been shown to be an active ingredient in traditional treatments for malarial fever. But what these researchers found indicates that borrelidin might be the strongest in the group.
They tested on both cultured human cells and E. coli bacteria, to analyze its effects on both eukaryotic and prokaryotic organisms. In both cases, the compound bound to four active sites in the tRNA synthesis enzyme. What the researchers described as an inhibitory overkill, it shuts down the enzyme extremely effectively and has extremely broad applications.
The hope is to analyze the structure and function further to develop compounds based on borrelidin. It's broad-spectrum applicability means that it could lead to better antibiotics, cancer treatments, malaria treatments, and even antifungal medication. The fact that it hits multiple targets means that it may be very difficult for pathogens to adapt around.
