Could a substance extracted from edible marine algae stop coronavirus from infecting human cells?
Ulvan, the major water-soluble polysaccharide extracted from the cell wall of green seaweed, could help stop coronavirus from infecting human cells, according to a team of researchers from Tel Aviv University.
“The lack of access to vaccines takes the lives of many victims and even accelerates the creation of new variants,” said TAU’s Prof. Alexander Golberg, who led the study on ulvan that was recently published in PeerJ − a peer-reviewed science journal. “The study is still in its early stages, but we hope that the discovery will be used in the future to develop an accessible and effective drug, preventing infection with the coronavirus.
“Our findings at this stage arouse cautious optimism,” he said.
Golberg and his team have been working with seaweed for the past eight years, looking for different compounds, mainly for the food industry. But he said that during the first lockdown, they started to think about how they could play a role in helping find solutions for the pandemic. Through other research they knew that certain seaweed compounds had antiviral properties and so decided they wanted to evaluate them against COVID.
Getting started proved a challenge, Golberg recalled, mainly because they needed access to the virus, which was not readily available in Israel. He said only the Israel Institute of Biological Research had it, so they had to look outside the country.
Ultimately, they partnered with a university in Alabama.
They then decided to test ulvan because it could be extracted from common seaweed.
“Ulvan is extracted from marine algae called Ulva, which is also called ‘sea lettuce,’ and is food in places like Japan, New Zealand and Hawaii,” Golberg explained. “It has previously been reported that ulvan is effective against viruses in agriculture and also against some of the human viruses − and when coronavirus arrived, we asked to test its activity.”
They grew Ulva algae, extracted the ulvan from it and sent it to the Southern Research Institute in Alabama. There, the US team built a cellular model to assess the activity of the substance produced in Golberg’s laboratory.
The cells were exposed to both the coronavirus and to ulvan. It was found that, in the presence of ulvan, the coronavirus did not infect cells.
“In other words,” he said, “ulvan prevents the cells from being infected with coronavirus.”
He stressed that the best thing would be to vaccinate the world. However, it has become clear that this is unlikely to happen − at least quickly.
“As long as billions in the low-income world do not have access to the vaccine… the virus is expected to develop more and more variants, which may be resistant to vaccines – and the war against the coronavirus will continue,” Golberg said. “For this reason, it is very important, for the sake of all mankind, to find a cheap and accessible solution that will suit even economically weak populations in developing countries.”
He noted that the ulvan the team used was actually a mixture of many natural substances and therefore more work is needed to determine specifically which is the one that prevents infection. Additionally, tests need to be done on small animals, monkeys and then, of course, humans.
Goldberg said bringing this solution to the market will take time, even with unlimited funding. But “if it can get there fast, it would be amazing.”