It was previously found to be a diet staple in those who were least likely to die from stroke or cardiac disease. It is also known to promote bone health, heart health, and digestive health.
The researchers prepared extracts of store-bought natto and applied them to the lab-grown SARS-CoV-2 and BHV-1 virus cultures. Later, the mixtures were added to human and cattle cells, respectively. This made the viruses fail from infecting the live human and cattle cells.
Similar effects were observed when the natto extracts were tested against the N501Y variant of SARS-CoV-2, which first originated in the UK.
How Could Natto Make It?
When the team applied heat-treated natto extracts to the same settings, the viruses were not harmed and were able to infect the cells. Thus, they hypothesized that the heat-sensitive proteases lie behind this antiviral action of natto extracts. Proteases are enzymes that destroy other proteins.
“We found what appears to be a protease or proteases (proteins that metabolize other proteins) in the natto extract directly digests the receptor-binding domain on the spike protein in SARS-CoV-2,” Mizutani said, noting that the protease appears to break down in the heat, losing the ability to digest proteins and letting the virus remain infectious.
They further tested their hypothesis by investigating the pattern of degradation of spike proteins through various chemical analyses.
While natto extracts seem to be powerful against SARS-CoV-2, the authors cautioned that their findings do not provide any direct evidence of reduced viral infection simply by eating natto.
“Although there are vaccines for COVID-19, we do not know how effective they may be against every variant. It will also take time to vaccinate everyone, and there are still reports of breakthrough cases, so we need to make treatments for those who develop COVID-19. This work may offer a big hint for such pharmaceutical design,” highlighted Mizutani.
The findings of this breakthrough research are published in the journal Biochemical and Biophysical Research Communications.
References
- Oba M, Rongduo W, Saito A, Okabayashi T, Yokota T, Yasuoka J, Sato Y, Nishifuji K, Wake H, Nibu Y, Mizutani T. Natto extract, a Japanese fermented soybean food, directly inhibits viral infections including SARS-CoV-2 in vitro. BiochemBiophys Res Commun. 2021 Jul 13;570:21-25. doi: 10.1016/j.bbrc.2021.07.034. Epub ahead of print. PMID: 34271432; PMCID: PMC8276596.
- The Nutritional Benefits of Fermented Superfood Natto
– (https://www.onegreenplanet.org/natural-health/nutritional-benefits-of-fermented-superfood-natto/)
Source: Medindia
