Rensselaer Polytechnic Institute (RPI)

In Cell Studies, Seaweed Extract Outperforms Remdesivir in Blocking COVID-19 Virus

Heparin, a common anitcoagulent, could also form basis of a viral trap for SARS-CoV-2

Newswise — TROY, N.Y. — In a test of antiviral effectiveness against the virus that causes COVID-19, an extract from edible seaweeds substantially outperformed remdesivir, the current standard antiviral used to combat the disease. Heparin, a common blood thinner, and a heparin variant stripped of its anticoagulant properties, performed on par with remdesivir in inhibiting SARS-CoV-2 infection in mammalian cells.

Published online today in Cell Discovery, the research is the latest example of a decoy strategy researchers from the Center for Biotechnology and Interdisciplinary Studies (CBIS) at Rensselear Polytechnic Institute are developing against viruses like the novel coronavirus that spawned the current global health crisis.

The spike protein on the surface of SARS-CoV-2 latches onto the ACE-2 receptor, a molecule on the surface of human cells. Once secured, the virus inserts its own genetic material into the cell, hijacking the cellular machinery to produce replica viruses. But the virus could just as easily be persuaded to lock onto a decoy molecule that offers a similar fit. The neutralized virus would be trapped and eventually degrade naturally.

Previous research has shown this decoy technique works in trapping other viruses, including dengue, Zika, and influenza A. To hear the researchers discuss their findings, watch this video.

“We’re learning how to block viral infection, and that is knowledge we are going to need if we want to rapidly confront pandemics,” said Jonathan Dordick, the lead researcher and a professor of chemical and biological engineering at Rensselaer Polytechnic Institute. “The reality is that we don’t have great antivirals. To protect ourselves against future pandemics, we are going to need an arsenal of approaches that we can quickly adapt to emerging viruses.” 

The Cell Discovery paper tests antiviral activity in three variants of heparin (heparin, trisulfated heparin, and a non-anticoagulant low molecular weight heparin) and two fucoidans (RPI-27 and RPI-28) extracted from seaweed. All five compounds are long chains of sugar molecules known as sulfated polysaccharides, a structural conformation that the results of a binding study published earlier this month in Antiviral Research suggested as an effective decoy.

The researchers performed a dose response study known as an EC50 — shorthand for the effective concentration of the compound that inhibits 50% of viral infectivity — with each of the five compounds on mammalian cells. For the results of an EC50, which are given in a molar concentration, a lower value signals a more potent compound.

RPI-27 yielded an EC50 value of approximately 83 nanomolar, while a similar previously published and independent in vitro test of remdesivir on the same mammalian cells yielded an EC50 of 770 nanomolar. Heparin yielded an EC50 of 2.1 micromolar, or about one-third as active as remdesivir, and a non-anticoagulant analog of heparin yielded an EC50 of 5.0 micromolar, about one-fifth as active as remdesivir.

A separate test found no cellular toxicity in any of the compounds, even at the highest concentrations tested.

 “What interests us is a new way of getting at infection,” said Robert Linhardt, a Rensselaer professor of chemistry and chemical biology who is collaborating with Dordick to develop the decoy strategy. “The current thinking is that the COVID-19 infection starts in the nose, and either of these substances could be the basis for a nasal spray. If you could simply treat the infection early, or even treat before you have the infection, you would have a way of blocking it before it enters the body.”

Dordick added that compounds from seaweed “could serve as a basis for an oral delivery approach to address potential gastrointestinal infection.” 

In studying SARS-CoV-2 sequencing data, Dordick and Linhardt recognized several motifs on the structure of the spike protein that promised a fit compatible with heparin, a result borne out in the binding study. The spike protein is heavily encrusted in glycans, an adaptation that protects it from human enzymes which could degrade it, and prepares it to bind with a specific receptor on the cell surface.

“It’s a very complicated mechanism that we quite frankly don’t know all the details about, but we’re getting more information,” said Dordick. “One thing that’s become clear with this study is that the larger the molecule, the better the fit. The more successful compounds are the larger sulfated polysaccharides that offer a greater number of sites on the molecules to trap the virus.” 

Molecular modeling based on the binding study revealed sites on the spike protein where the heparin was able to interact, raising the prospects for similar sulfated polysaccharides. 

“This exciting research by Professors Dordick and Linhardt is among several ongoing research efforts at CBIS, as well as elsewhere at Rensselaer, to tackle the challenges of the COVID-19 pandemic through novel therapeutic approaches and the repurposing of existing drugs,” said CBIS Director Deepak Vashishth.

Sulfated polysaccharides effectively inhibit SARS-CoV-2 in vitro” was published in Cell Discovery with the support of the National Research Foundation of Korea. At Rensselaer, Dordick and Linhardt were joined in the research by Paul S. Kwon, Seok-Joon Kwon, Weihua Jin, Fuming Zhang, and Keith Fraser, and by researchers at the Korea Research Institute of Bioscience and Biotechnology in Cheongju, Republic of Korea, and Zhejiang University of Technology in Hangzhou, China.

About Rensselaer Polytechnic Institute

Founded in 1824, Rensselaer Polytechnic Institute is America’s first technological research university. Rensselaer encompasses five schools, 32 research centers, more than 145 academic programs, and a dynamic community made up of more than 7,900 students and over 100,000 living alumni. Rensselaer faculty and alumni include more than 145 National Academy members, six members of the National Inventors Hall of Fame, six National Medal of Technology winners, five National Medal of Science winners, and a Nobel Prize winner in Physics. With nearly 200 years of experience advancing scientific and technological knowledge, Rensselaer remains focused on addressing global challenges with a spirit of ingenuity and collaboration. To learn more, please visit www.rpi.edu.

SEE ORIGINAL STUDY



Filters close

Showing results

110 of 5845
Released: 17-Jun-2021 4:15 PM EDT
UNC Researchers Lead Study of Diabetes Treatment of COVID-19 Patients
University of North Carolina School of Medicine

Diabetes is one of the comorbidities most strongly associated with severe COVID-19 in the US, and data from early in the pandemic suggested individuals with type 2 diabetes faced twice the risk of death from COVID-19 and a greater risk of requiring hospitalization and intensive care. A new study shows best treatment options.

Released: 17-Jun-2021 4:10 PM EDT
Vaccination, Previous Infection, Protect Against COVID-19 gamma/P.1 Variant in Animal Model
University of Wisconsin-Madison

In a new study using variant virus recovered from one of the original travelers, researchers in the U.S. and Japan have found that vaccination with an mRNA vaccine induces antibody responses that would protect humans from infection with the gamma/P.1 variant.

Newswise:Video Embedded virtual-event-for-june-17-11am-edt-covid-19-vaccines-and-male-fertility
VIDEO
Released: 17-Jun-2021 3:20 PM EDT
VIDEO AVAILABLE: Vaccines and Male Fertility Event for June 17, 2021
Newswise

This upcoming JAMA-published study examined whether the COVID-19 vaccine impacts male fertility.

Released: 17-Jun-2021 1:30 PM EDT
Hackensack Meridian Doctors, Student Help Establish Way to Prioritize Surgeries During COVID-19 lockdown
Hackensack Meridian Health

The MeNTS method of prioritizing surgeries during the height of pandemic, developed by University of Chicago, helped procedures continue during time of need

Released: 17-Jun-2021 12:55 PM EDT
‘Nanodecoy’ Therapy Binds and Neutralizes SARS-CoV-2 Virus
North Carolina State University

Nanodecoys made from human lung spheroid cells (LSCs) can bind to and neutralize SARS-CoV-2, promoting viral clearance and reducing lung injury in a macaque model of COVID-19.

access_time Embargo lifts in 2 days
Embargo will expire: 21-Jun-2021 11:00 AM EDT Released to reporters: 17-Jun-2021 12:10 PM EDT

A reporter's PressPass is required to access this story until the embargo expires on 21-Jun-2021 11:00 AM EDT The Newswise PressPass gives verified journalists access to embargoed stories. Please log in to complete a presspass application. If you have not yet registered, please Register. When you fill out the registration form, please identify yourself as a reporter in order to advance to the presspass application form.

Newswise: Blood Cancer Patients with COVID-19 Fare Better with Convalescent Plasma
Released: 17-Jun-2021 11:55 AM EDT
Blood Cancer Patients with COVID-19 Fare Better with Convalescent Plasma
Washington University in St. Louis

A large, retrospective, multicenter study involving Washington University School of Medicine in St. Louis indicates that convalescent plasma from recovered COVID-19 patients can dramatically improve likelihood of survival among blood cancer patients hospitalized with the virus. The therapy involves transfusing plasma — the pale yellow liquid in blood that is rich in antibodies — from people who have recovered from COVID-19 into patients who have leukemia, lymphoma or other blood cancers and are hospitalized with the viral infection.

Released: 17-Jun-2021 11:05 AM EDT
Stress during pandemic linked to poor sleep
Washington State University

Many people likely lost sleep over COVID-19. A study of twins led by Washington State University researchers found that stress, anxiety and depression during the first few weeks of the pandemic were associated with less and lower quality sleep.

Newswise:Video Embedded university-of-miami-miller-school-study-shows-covid-19-mrna-vaccines-do-not-impact-male-fertility
VIDEO
Released: 17-Jun-2021 11:00 AM EDT
University of Miami Miller School Study Shows COVID-19 mRNA Vaccines Do Not Impact Male Fertility
University of Miami Health System, Miller School of Medicine

The Pfizer and Moderna mRNA COVID-19 vaccines is safe for male reproduction, according to a new study by University of Miami Miller School of Medicine researchers published in JAMA , the most widely circulated general medical journal in the world.

15-Jun-2021 1:20 PM EDT
Higher COVID-19 Mortality Among Black Patients Linked to Unequal Hospital Quality
Perelman School of Medicine at the University of Pennsylvania

If Black patients were admitted to the same hospitals that serve a majority of White patients, researchers showed their risk of death would drop by 10 percent


Showing results

110 of 5845

close
1.59951