In preliminary tests, researchers from the University of Florida Health found that two over-the-counter medicines inhibited COVID-19 viruses. It contains diphenhydramine, an antihistamine for allergies.
During tests on monkey cells and human lung cells, the compounds were found to hinder the SARS-CoV-2 virus when paired with lactoferrin, a protein found in cow and human milk.
The study’s findings were published in Pathogens by David A. Ostrov, Ph.D., an immunologist affiliated with the UF College of Medicine’s department of pathology, immunology, and laboratory medicine, with colleagues.
“We found out why certain drugs are active against the virus that causes COVID-19. Then, we found an antiviral combination that can be effective, economical, and has a long history of safety,” Ostrov explained.
Ostrov knew from earlier research he conducted at UF that diphenhydramine could be useful for treating the SARS-CoV-2 virus.
Researchers from COVID-19, which is part of the Global Virus Network, discovered the latest disease during a routine meeting.
Meanwhile, Unpublished data presented by one researcher shows that lactoferrin inhibits SARS-CoV-2 activity.
Ostrov came up with the idea of pairing lactoferrin with diphenhydramine and went ahead with it. The combination was especially effective in laboratory tests conducted on human and monkey cells.
SARS-CoV-2 virus replication was inhibited by 30% by the two compounds individually. By combining the two compounds, they prevented virus replication by 99%.
According to Ostrov, the findings are an important first step in developing a formulation to accelerate the recovery of COVID-19.
A human clinical trial focused on preventing COVID-19 might also be possible through a partnership between academia and industry.
Mouse models are already being tested for the compounds’ effectiveness in preventing COVID-19.
Scientists analyzed proteins called sigma receptors expressed in human cells to establish their findings.
During COVID-19 infections, the virus tries to replicate in the body through stress-response mechanisms, including sigma receptors.
To inhibit the virus’s potency, it appears that it is essential to interfere with that signaling.
“We now know the detailed mechanism of how certain drugs inhibit SARS-CoV-2 infection,” Ostrov said.
These experiments revealed that a targeted sigma receptor binding drug candidate and effective over-the-counter combinations can reduce the severity of COVID-19 infection and the time it takes to recover from it, the researchers reported.
In spite of the encouraging findings, Ostrov discourages using diphenhydramine or lactoferrin in a preventative or treatment for COVID-19.
Those who conduct the research used a different form of lactoferrin than what is commonly available to consumers, he noted.
Furthermore, it is important to note that to treat stomach and intestinal ulcers, lactoferrin is sometimes taken as a supplement.