If we did not have enough reasons to consume the five servings of fruits and vegetables recommended by the World Health Organization (WHO) daily, now a study gives us one more, since it has found that a chemical derived from a compound -sulforaphane – Present in green leafy vegetables such as broccoli, it can slow down the growth of some coronaviruses, such as SARS-CoV-2 –responsible for the COVID-19 pandemic–, or the common cold virus.
Sulforaphane is a plant-derived chemical known as a phytochemical that has previously been shown to have anticancer effects. The new research has been led by scientists at the Johns Hopkins Children’s Center, and has been published in Nature Communications Biology, and its results show that sulforaphane could help prevent and treat diseases caused by some coronaviruses, including COVID-19.
The natural precursor to sulforaphane is especially abundant in broccoli, cabbage, kale, and Brussels sprouts. Studies conducted decades ago by scientists at Johns Hopkins and other centers had found that sulforaphane has properties to prevent cancer and infection by interfering with certain cellular processes, and now it has been shown that sulforaphane can inhibit the replication of SARS -CoV-2 and other human coronaviruses in cells and mice.
Sulforaphane is also effective against delta and omicron variants.
“When the COVID-19 pandemic began, our multidisciplinary research teams shifted our investigations from other viruses and bacteria to focus on a potential treatment for what was then a challenging new virus for us,” said microbiologist Lori Jones-Brando. , assistant professor of pediatrics at Johns Hopkins University School of Medicine and lead author of the paper, adding: “I was screening several compounds for activity against coronavirus and decided to try sulforaphane, as it has shown modest activity against other microbial agents that we study”.
“Sulforaphane is antiviral against the coronaviruses HCoV-OC43 and SARS-CoV-2 and, at the same time, helps control the immune response”
Purified synthetic sulforaphane purchased from commercial chemical suppliers was used to carry out the research. The researchers performed a first experiment in which they exposed cells to sulforaphane for one to two hours before infecting them with SARS-CoV-2 and HCoV-OC43, which is the common cold coronavirus. They found that low micromolar (µM) concentrations of sulforaphane (2.4–31 µM) reduced the replication of six strains of SARS-CoV-2, including delta and omicron variants, and that of coronavirus HCoV-OC43 by 50%. .
In the case of cells that had been previously infected with the viruses, similar results were obtained, observing that sulforaphane provided protective effects even with an established viral infection.
Combining sulforaphane with remdesivir reduced viral load
The researchers also looked at the effects of sulforaphane in combination with remdesivir, an antiviral drug used to speed recovery in adults hospitalized for COVID-19. Remdesivir inhibited 50% of the replication of HCoV-OC43 and SARS-CoV-2 at 22 µM and 4 µM, respectively. And these experts say that sulforaphane and remdesivir interacted synergistically at various combination ratios to reduce viral load in cells infected with HCoV-OC43 or SARS-CoV-2 by 50%. In this context, synergism means that lower doses of sulforaphane (for example, 1.6 to 3.2 µM) and remdesivir (for example, 0.5 to 3.2 µM), are more effective against viruses when are combined than if they are administered separately.
“Historically, we have learned that combining multiple compounds in a treatment regimen is an ideal strategy for treating viral infections,” explains Álvaro Ordóñez, MD, first author of the paper and assistant professor of pediatrics at Johns University School of Pediatrics. Hopkins. of Medicine. “The fact that sulforaphane and remdesivir work better together than alone is very encouraging.”
Subsequently, they conducted tests in a mouse model of SARS-CoV-2 infection and found that administering 30 milligrams of sulforaphane per kilogram of body weight to mice before infecting them with the virus significantly reduced body weight loss. usually associated with infection by the virus (decrease of 7.5%). And there was also a statistically significant reduction in both the viral load in the lungs (17% decrease) and in the upper respiratory tract (9% decrease), as well as in the amount of lung injury (29% decrease), in comparison with infected mice that were not administered sulforaphane.
The compound also reduced inflammation in the lungs, preventing an overactive immune response that has been considered one of the factors involved in the severity of COVID-19 and in many patients dying from it. “What we found is that sulforaphane is antiviral against the coronaviruses HCoV-OC43 and SARS-CoV-2 and, at the same time, helps control the immune response,” says Ordóñez. “This multifunctional activity makes it an interesting compound to use against these viral infections, as well as those caused by other human coronaviruses.”
Although the findings of the study are very promising, its authors have warned the population not to rush out and buy nutritional supplements that include sulforaphane and that can be purchased online or in physical stores, because it is still necessary to carry out studies on the effectiveness of this compound in humans.
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