Friday, February 10, 2023

University of Sydney scientists make ‘crazy’ Covid-19 discovery

The COVID public health emergency is coming to an end, and even thought you might not have been following protocols recently, this will still affect you and your wallet.
Australian scientists have made an incredible discovery that could change the way we view Covid — and could explain why some people suffer serious illness with the virus, or even death, while others never get sick or appear symptomless.

University of Sydney researchers discovered a protein in the lung that blocks Covid infection and forms a natural protective barrier in the human body.

The naturally occurring protein, LRRC15, works by attaching itself to the virus, stopping Covid particles from binding with more vulnerable cells - as well as reducing the chance of infection.

The research offers a promising pathway to develop new drugs to prevent Covid or deal with fibrosis in the lungs.

The study led by Professor Greg Neely found that this new receptor acts by binding to the virus and sequestering it which reduces infection.

“For me, as an immunologist, the fact that there’s this natural immune receptor that we didn’t know about, that’s lining our lungs and blocks and controls viruses, that’s crazy interesting,” Professor Neely said.

“We can now use this new receptor design broad acting drugs that can block viral infection or even suppress lung fibrosis.”

How it works

The Covid-19 virus infects humans by using a spike protein to attach to a specific receptor in our cells. It primarily uses a protein called the angiotensin-converting enzyme 2 (ACE2) receptor to ender human cells.

Lung cells have high levels of ACE2 receptors, which is why the Covid-19 virus often causes severe problems in this organ.

Like AEC2, LRRC15 is a receptor for Covid meaning the virus can bind to it. But unlike ACE2, LRRC15 does not support infection.

It can however stick to the virus and immobilise it.

Researchers believe patients who died from Covid did not produce enough of the protein, or produced it too late to make a difference.

“We think it acts a bit like Velcro, molecular Velcro, in that it sticks to the spike of the virus and then pulls it away from the target cell types,” another researcher Dr Lipin Loo said.

The breakthrough comes as millions of Australians are now eligible for a fifth Covid vaccine within a fortnight.

The Australian Technical Advisory Group on Immunisation has recommended that all people aged 18 and over receive a top-up jab, no matter how many doses they’ve already received, as long as they have not been infected with the virus in the last six months.

Up to four million Australians are estimated to have been struck down with Covid-19 just in the past four months.

More than 2600 Australians have died with the virus since October. Around 800 of those deaths were aged care residents.


Can Plant Extracts Effectively Inhibit SARS-CoV-2—The Results of a Portugal Review Study Look Promising

Can natural products be used as a means of combating COVID-19? Afterall, plant-based chemistry has been at work in Traditional Chinese Medicine (TCM) for centuries, based on plants: long the source of individual molecules and extracts capable of inhibiting/neutralizing several microorganisms, including viruses.

In fact, natural extracts have demonstrated potential efficacy against various pathogens in the coronavirus families, although that fact isn’t touted much by mainstream media in the West. But plenty of misinformation associated with this topic continues to circulate across cyberspace. There are reasons medical products are tightly regulated at the national level.

Only after careful and systematic research demonstrating safety and effectiveness will such natural products be authorized by relevant authorities. In that spirit, recently, a group of collaborating scientists from Portugal, affiliated with the Mountain Research Institute and the Catholic University of Portugal (Center for Biotechnology and Fine Chemistry), investigated select plant metabolites and their potential therapeutic value targeting SARS-CoV, the virus behind COVID-19.

Of particular interest to the Portugal-based scientists, represented by corresponding author Lillian Barros, Ph.D., a biotech engineer with a focus on biotechnology and food chemistry, was a couple of molecules associated with Traditional Chinese Medicine (TCM) as the world’s biggest population depends heavily on this approach targeting COVID-19.

What are the primary strategies to inhibit or stop SARS-CoV-2, the virus behind COVID-19?

Researchers have determined a couple pathways for therapy to work, including 1) inhibiting of SARS-CoV-2 penetration by preventing SARS-CoV-2 S-ACE2 binding interactions and 2) the inhibiting of protease enzymes such as Mpro (main protease), 3CLpro (3C-like protease) and PLpro (papain-like protease).

Enter this investigation into plant metabolites targeting SARS-CoV-2

The study team centered their investigation on select plants associated with TCM, for example, and the derived molecules that can actually bind with glycoprotein and consequently stop membrane fusion included A) luteolin (11 µM) and TGG (tetra-O-galloyl-β-D-glucose, 5.0 µM), both taken from TCM that do bind with spike glycoprotein. The team looked at other plant-based molecules.

The study team used the SCOPUS database and associated software to better understand a relation between plants and SARS-CoV02. They report about 1504 documents surfaced based on targeted keywords from 2020 to 2022. Selecting output with at least one of the chosen search terms, the team used specialized software to organize output by relevance and relationship.

What’s interesting about plant-based molecules potentially capable of stopping what’s known as cysteine proteases?
It turns out that SARS-CoV-2 thrives thanks to an enzyme called 3CLpro, responsible for the processing of proteins essential for the novel coronaviruses thriving. Hence why, drugs such as Paxlovid fall in the class of 3CLpro inhibition.

Other inhibitors involving both PLpro and 3CLpro identified by the researchers include chalcones, especially chalcone 6 as well. Some properties associated with plans inhibit PLpro with more effectiveness—such as polyphenol compounds taken from the leaves of the paper mulberry tree native to eastern Asia.

Overall, the team reported in their paper published in MDPI that of the compounds studied, Papyriflavonol A shows superior ability to inhibit PLpro enzyme. While one compound could inhibit both the relevant proteins—PLpro and 3CLpro: Salvia miltiorrhiza Bunge-derived lipophilic tanshinones.

The researchers analyze the plant-based metabolites’ potential for contributing to regimen targeting SARS-CoV-2, including several other examples.

What’s a takeaway?

The scientific literature suggests a definite therapeutic value associated with certain plant extracts, including ones involved in TCM, targeting SARS-CoV-2, the virus behind COVID-19. The Portuguese researchers document a particular interest in bioactive molecules such as alkaloid compounds as well as phenolic substances from chalcones and flavonoids to tannins and lignins to glycosides.

Likely, with targeted focus and investment in this plant-based medicinal approach, companies focusing on this area could offer substantially safe and effective, not to mention economical treatments against COVID-19. But would this fit into the biopharmaceutical business model?




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