Hidden Gem: A Salt Marsh Plant May Hold a Cure for Malaria

Scientists discover new antimalarial chemicals in a salt marsh plant species traditionally used in folk medicine in Korea

Many researchers on the quest for novel bioactive substances have recently begun to focus on marine resources. But plants that grow in tidal flats remain largely unexplored. Now, scientists from the Korea Maritime and Ocean University discover that Vitex rotundifolia, a salt marsh plant used in traditional medicine in Korea, produces several chemicals with antimalarial properties, showcasing the untapped potential of salt marsh plants for the development of botanical drugs.  

Tidal flats are marshy portions of land that are covered and uncovered by the rise and fall of the tides. These unique ecosystems are home to many species of salt marsh plants that manage to thrive in high salinity conditions thanks to their unique internal chemistry. Could chemical compounds produced by these plants be a novel source of bioactive compounds useful to humans?

According to a recent study published in Bioorganic Chemistry, the answer is a resounding yes! A team of scientists, including Prof Youngwan Seo from the Division of Marine Bioscience at Korea Maritime and Ocean University, discovered that a salt marsh plant native to countries across the Pacific seas from Korea to Australia, Hawaii, and India, called Vitex rotundifolia, may hold the secrets to a novel anti-malaria drug. Using advanced spectroscopic techniques, the scientists extracted and identified eight different diterpenoids―a class of organic molecules with antimicrobial properties―from V. rotundifolia samples. They then tested the effects of these compounds on malaria cultures.

Three of these compounds turned out to have remarkable antimalarial effects, one of which was even new to science. V. rotundifolia has been used in traditional folk medicine for centuries, and it is therefore very likely that the plant is not toxic to humans. Moreover, the team of scientists compared the structures of the extracted diterpenoids and gained some insight into the possible causes of their different antimalarial qualities. Excited about the results, Prof Seo comments: “Though marine organisms are currently in the spotlight as a source of new bioactive substances, tidal flat plants haven’t attracted that much interest. Our findings showcase the potential of salt marsh plants inhabiting the brackish waters of Korea for the development of botanical drugs.”

Considering that malaria is among the deadliest infectious diseases, the promising findings of this study light a beacon of hope for those exposed to this mosquito-borne threat. Prof Seo also remarks: “As antibiotic resistance increases and terrestrial resources become scarce, unconventional marine resources such as salt marsh plants will become increasingly important.” What other useful substances will we find among the approximately one hundred species of salt marsh plants growing in the Korean Peninsula? Only time will tell!

DOI: 10.1016/j.bioorg.2020.103925

*Corresponding author’s email: ywseo@kmou.ac.kr

About the author

Dr Youngwan Seo received a PhD in organic synthetic chemistry from Seoul National University, Korea, in 1991. He then worked at the Korea Ocean Research and Development Institute (KORDI), where he studied the isolation, structure elucidation, and structure-activity relationships of biologically active marine natural products. In 1999, he joined Kingston’s group at Virginia Tech, USA, as a research associate. He later became a Professor at the Division of Marine Bioscience at the Korea Maritime and Ocean University. His research interests are the isolation, structure determination, and chemical transformation of biologically active natural products from marine organisms, with a particular focus on their antioxidant, anti-inflammatory, anti-photoaging, and anticancer properties.