As researchers discover why sweetgrass is an efficient insect repellent, they also reveal the importance of studying the popular remedies that people have been using for many years years now.
Identifying the scientific explanation for the success of these remedies might actually herald the discovery of newer and more potent substances that could be valuable alternatives in the treatment of numerous diseases.
Sweetgrass has been used as an insect repellent by the native Americans for a great many years. Since it is considered to be extremely effective in keeping mosquitoes away, a team of researchers wanted to understand what exactly makes the plant so useful in fighting off the small pests, as the world is in dire need of less toxic but more potent substances for managing the mosquito population, because the mosquito is a vector for some of the world’s worst diseases.
The study was led by Dr. Charles Cantrell of the U.S. Department of Agriculture. Together with his team of researchers, he took the sweetgrass and extracted essential oil from it, as well as several other active compounds.
Then, they conducted an experiment that was meant to test out the potency of the sweetgrass oil, as compared to N,N-diethyl-m-toluamide, commonly known as DEET, which is an efficient commercial repellent on the market.
The team used a specialized feeding solution that they died red in order to lure the mosquitoes in. The vials of feeding solution were topped off with a membrane, mean to simulate human skin, that the repellents were added to, just as an insect repellent would be used in practice. They tested out the DEET and the selection of sweetgrass-based compounds they had extracted. They measured the potency of the repellents in accordance to the number of mosquito bites that each vial got.
Their findings revealed that the essential oil they had extracted from sweetgrass was the most potent compound in it and that it was about as efficient as the DEET.
Then, they realized they had to go deeper and see what exactly was making the sweetgrass so efficient. And so, they used state of the art spectrometry and spectroscopy techniques to study the sweetgrass oil and they succeeded in separating it into a total of 12 fractions.
This is how they revealed that the two substances that give sweetgrass its repellent properties are actually coumarin and phytol. These are not new to the scientific community, but the full extent of their insect repellent properties was apparently not known.
Dr. Cantrell has pointed out that further research is required in order to test out the efficacy of the sweetgrass oil in a much more detailed manner before it could be considered appropriate for being included in insect repellent formulas.
It remains to be seen what this research will reveal, but sweetgrass oil might be a less toxic version of an insect repellent that people could use to keep safe from mosquitoes.
Image Source: ecoseeds