Study: Possible New Antivirals May Be Protective Against Herpes, Other Infections

A new report by the American Chemical Society suggests that peptoids that were successful in helping treat animals with herpes infections may help prevent other kinds of infections, including COVID-19.

“In the body, antimicrobial peptides such as LL-37 help keep viruses, bacteria, fungi, cancer cells and even parasites under control,” said one of the study’s principal investigators Annelise Barron, PhD, in the press release. Barron added that because they are quickly cleared by enzymes, they are not ideal drug candidates.

“Peptoids are easy to make,” Barron said in the press release. “And unlike peptides, they’re not rapidly degraded by enzymes, so they could be used at a much lower dose.”

Peptoids are simple and inexpensive to produce with an automated synthesizer and readily available chemicals, according to the researchers. They added that side chains are linked to nitrogens in the molecular backbone, forming a structure that resists enzymes.

Barron and her team developed peptoids as clinical candidates to prevent or treat viral infections, with a recent report of their newest peptoid sequences that were designed to be less toxic to people than previous versions. The compounds inactivated SARS-CoV-2 in lab dishes, making the viruses incapable of infecting cultured human cells, according to the study authors.

The researchers reported in vivo results, showing that the peptoids safely prevented herpes infections in mice when dabbed on their lips. Additional experiments are being conducted to confirm these findings, including the peptoids’ efficacy against HSV-1 strains that are resistant to acyclovir, according to Barron.

“COVID-19 infection involves the whole body, once somebody gets really sick with it, so we will do this test intravenously, as well as looking at delivery to the lungs,” Barron said in the press release.

Barron noted that she has sent peptoid samples to experts in other labs to test against a range of viruses, with positive results in lab dish studies against influenza, the cold virus, and hepatitis B and C.

“In their in vitro studies, a team found that two of the peptoids were the most potent antivirals ever identified against MERS and older SARS coronaviruses,” Barron said in the press release.

Other labs are testing peptoids as anti-fungals for airways and the gut, and further as anti-infective coatings for contact lenses, catheters, and implanted hip and knee joints, according to the press release.

By studying how these broad-spectrum compounds work, the researchers have the advantage of inactivating the virus, which is not common for standard antivirals that slow viral replication but still allow viruses to infect cells. This also makes it less likely for the pathogens to develop resistance, according to the study.

Barron and her team hope for clinical trials to begin within the year, and if successful, she said peptoids could be given as a new preventative or after an infection happens in a person.

REFERENCE

Possible new antivirals against COVID-19, herpes. ACS. August 24, 2021. Accessed August 25, 2021. https://www.acs.org/content/acs/en/pressroom/newsreleases/2021/august/possible-new-antivirals-against-covid-19-herpes.html