In vitro antiviral effect of germacrone on feline calicivirus

Abstract

Feline calicivirus (FCV) often causes respiratory tract and oral disease in cats and is a highly contagious virus. Widespread vaccination does not prevent the spread of FCV. Furthermore, the low fidelity of the RNA-dependent RNA polymerase of FCV leads to the emergence of new variants, some of which show increased virulence. Currently, few effective anti-FCV drugs are available. Here, we found that germacrone, one of the main constituents of volatile oil from rhizoma curcuma, was able to effectively reduce the growth of FCV strain F9 in vitro. This compound exhibited a strong anti-FCV effect mainly in the early phase of the viral life cycle. The antiviral effect depended on the concentration of the drug. In addition, germacrone treatment had a significant inhibitory effect against two other reference strains, 2280 and Bolin, and resulted in a significant reduction in the replication of strains WZ-1 and HRB-SS, which were recently isolated in China. This is the first report of antiviral effects of germacrone against a calicivirus, and extensive in vivo research is needed to evaluate this drug as an antiviral therapeutic agent for FCV.

Antiviral effect of copper chloride on feline calicivirus and Synergy with Ribavirin in vitro

“…Then, we demonstrated the inhibitory effect of copper chloride on the viral titre and RNA levels of FCV at different time points. FCV was significantly inhibited when copper chloride was added 8 h after FCV was used to infect the cells, but copper chloride did not significantly inhibit FCV after 16 h. Our findings were similar to those of previous studies using fexaramine, LiCl, ginger extracts,or CSX [13,14,27,28], we speculated that copper chloride could hinder attachment and entry of FCV and inhibit the replication inside the cell, but its mechanism of inhibiting replication needed further verification.…”

“…However, due to the high evolutionary rate of the FCV capsid protein, with as many as 1.3×10 -2 to 2.6×10 -2 substitutions per nucleotide per year [10], traditional vaccination cannot completely protect the animals from re-infection of mutant or wild-type strains, even if the FCV was considered to have only one serotype [11]. Therefore, it is necessary to develop a safe and effective antiviral drug as a monotherapy or as part of a combination treatment.In previous studies, various compounds had been found to have anti-FCV effects, such as minomorpho oligophosphate (PMO), lithium chloride, and germacrone [12][13][14]. The combination of mefloquine and recombinant cat interferon-ω had a synergetic effect against FCV [15].…”

Equine immunoglobulin F(ab')2 fragments protect cats against feline calicivirus infection

“…There have been many reports on anti-FCV drugs in recent years. Hongxia Wu et al discovered the inhibitory effects of germacrone and LiCl on FCV [4,5]. In addition to synthetic compounds, Korea red ginseng extracts (KRGE) and ginsenosides, grape seed extracts (GSE), ginger extracts, clove extracts and phaeophyta extracts can also resist FCV [6][7][8][9].…”

Antiviral Activity of Germacrone against Pseudorabies Virus in Vitro

“…In particular, germacrone antitumor effect on the human hepatoma cell line is mediated via G2/M cell cycle arrest and by promoting apoptosis [19]. In terms of antiviral activity, germacrone inhibits influenza virus (IAV), Porcine parvovirus (PPV), Feline calicivirus (FCV), and Porcine reproductive and respiratory syndrome virus (PRRSV) replication [16,[20][21][22]. Germacrone has inhibitory effects on H1N1, H3N2 influenza viruses, and Influenza B viruses in the early stages of the viral cycle and can protect mice from fatal infection [20].…”