A joint study by scientists from Malaysia and Russia showed that fern extract Nephrolepis biserrate could be efficiently used as an antibiotic alternative in aquaculture.
In particular, the researchers found the extract to be effective against bacteria of the genus Vibrio, which is widely known in aquaculture for posing a serious threat to farmed seafood. Infected fish get sick and die quickly, which incurs substantial losses to fish farms.
Another side of the problem is that this bacterium is dangerous for humans – the pathogen can cause blood poisoning and tissue necrosis. It can be transmitted to humans by eating contaminated seafood or through open wounds.
The scientists investigated the antibacterial properties of the fern Nephrolepis biserrata, which is native to South America, Southeast Asia and Africa. In more northern latitudes, fern is grown as an ornamental houseplant. The plant has also long been used in traditional medicine, including to treat infections.
The findings suggest that an aqueous fern extract could be used as a natural alternative to fight infections in aquaculture systems
During a series of trials, the fern extract was found to inhibit the activity of bacteria of the genus Vibrio, the scientists said, not going too deep into details.
In addition, experiments have shown that the plant extract is effective against leeches Zeylanicobdella arugamensis, a parasite also known to fish farmers. The scientists said that antibiotics are also frequently used to combat it, though this method has certain disadvantages.
The study’s authors added that searching for alternative methods of combating bacterial infections is an important task. According to scientists, some natural compounds found in plants are increasingly seen as an alternative to feed antibiotics.
The fern extract showed similar effectiveness against Zeylanicobdella arugamensis as synthetic antibiotics, the scientists claimed, again not providing concrete details. They believe that phenols and flavonoids, as well as various aromatic compounds such as cinnamic acid, are responsible for the extract’s antibiotic effect.
“The findings suggest that an aqueous fern extract could be used as a natural alternative to fight infections in aquaculture systems. Obviously, fern aqueous extract is a promising functional product for fish farming or aquaculture. On its basis, feed for farmed fish can be made, as well as means to improve the quality of the aquatic environment,” said Olga Babich, one of the study’s authors.