Study: Active Substance Inhibits Viral Replication of Hepatitis E Virus

Silvestrol, an active substance formed by 400 different types of mahogany plants, may be key to developing a potential cure for hepatitis E virus (HEV), according to a recent study published in Antiviral Research.

Although acute infections caused by HEV typically resolve by themselves, the virus can become chronic in patients with reduced or suppressed immune systems, such as organ transplant recipients or HIV-positive patients. Additionally, women who are pregnant are more likely to experience severe illness due to HEV that can lead to death. While rare in the United States, HEV is common in many other parts of the world.

Researchers from Ruhr-Universität Bochum are the first to have established a comprehensive test system for active substances against HEV, from cell culture and stem cells to animal models, according to a press release.

For the study, the researchers investigated the effect of silvestrol on the virus.

“We first treated what are known as reporter viruses with silvestrol in cell cultures and found that they replicated less than without the treatment,” study author Daniel Todt, PhD, said in a press release.

Following this finding, the researchers used stem cells to differentiate into liver cells and infected them with HEV. Over the course of several days, they observed the course of infection with and without silvestrol.

According to the results, treatment with silvestrol caused the multiplication rate and the number of infected cells to decrease significantly. The researchers noted that the effect of silvestrol was stronger than that of ribavirin, the only drug currently used to treat HEV. Furthermore, treatment with silvestrol led to reduced replication of the virus in mice that were implanted with human liver cells infected with HEV, which confirms the substance’s ability to inhibit viral replication in living organisms, according to the study.

There were no observed adverse effects in small doses, they noted.

Although the research is still in its early stages, the findings raise hope that silvestrol may be an effective treatment for hepatitis E, according to the study authors. The substance’s ability to inhibit the replication of pathogens in both cell cultures and in the mouse model is promising.

“The clinical potential must be explored in further studies,” study author Eike Steinmann, PhD, said in the press release. “Our research is laying the foundations for this.”

Reference

Todt D, Moeller N, Praditya D, et al. The natural compound silvestrol inhibits hepatitis E virus (HEV) replication in vitro and in vivo. Antiviral Research. 2018. doi: 10.1016/j.antiviral.2018.07.010.

Active substance raises hopes of curing hepatitis E [news release]. RUB’s website. http://news.rub.de/english/press-releases/2018-08-01-virology-active-substance-raises-hopes-curing-hepatitis-e. Accessed August 2, 2018.