Effect of EGCG Extracted from Green Tea against Largemouth Bass Virus Infection

Abstract

(1) Background: Largemouth bass virus (LMBV) is a major viral pathogen in largemouth bass (Micropterus salmoides) aquaculture that often causes high mortality and heavy economic losses, thus developing treatments to combat this pathogen is of great commercial importance. Green tea is a well-known medicinal plant that contains active ingredients with antiviral, antibacterial, and other biological activities. The goals of this study were to explore the effect and mechanism of green tea source compounds on LMBV and provide data to serve as the basis for the screening of targeted drugs in the future. In this study, we evaluated the effects of the main component of green tea, epigallocatechin-3-gallate (EGCG), against LMBV infection. (2) Methods: The safe working concentration of EGCG was identified by cell viability detection and light microscopy. The antiviral activity and mechanism of action of EGCG against LMBV infection were evaluated with light microscopy, an aptamer 6-carboxy-fluorescein-based fluorescent molecular probe, and reverse transcription quantitative PCR. (3) Results: The safe working concentration of EGCG was ≤10 μg/mL. EGCG showed significant anti-LMBV infection activity in a concentration-dependent manner, and it also destroyed the structure of virus particles. EGCG impacted the binding of virus particles to cell receptors and virus invasion into the host cells. Inhibitory effects of EGCG on LMBV particles, LMBV binding to the host-cell membrane, and LMBV invasion were 84.89%, 98.99%, and 95.23%, respectively. Meanwhile, the effects of EGCG subsequently were verified in vivo. The fatality rate of the LMBV + EGCG group was significantly lower than that of the LMBV group. (4) Conclusions: Our results suggest that EGCG has effective antiviral properties against LMBV and may be a candidate for the effective treatment and control of LMBV infections in largemouth bass aquaculture.

Antiviral Effect and Mechanism of Edaravone against Grouper Iridovirus Infection

“…Liu et al found that quercetin had a damaging effect on the particles of SGIV, thereby inhibiting the infective ability of SGIV [27]. Cheng et al used EGCG to treat the LMBV virus and found a significant decrease in the infectivity of LMBV [48]. In the present study, we likewise evaluated the effect of edaravone on SGIV particles.…”

Isolation, identification, and monoclonal antibody development of largemouth bass virus

“…While several vaccines and herbal extracts have shown efficacy in preventing LMBV infection, there are currently no approved vaccines or drugs available for its prevention or treatment (Yao et al, 2022;Cheng et al, 2023;Wang et al, 2023;Zhang, M. et al, 2023). Moreover, infected fish with LMBV experience rapid mortality once symptoms appear…”

“…Vaccination is considered an ideal approach for preventing LMBV infection. Although some candidate vaccines and herbal extracts have been proven to be potent for defending against LMBV infection under laboratory conditions, there is no licensed vaccine or antiviral drug available for preventing or treating LMBV infection (Jia et al, 2022;Yao et al, 2022;Cheng et al, 2023;Wang et al, 2023;Zhang, M. et al, 2023). Therefore, rapid detection and early diagnosis of LMBV remain crucial strategies to prevent the disease's spread and mitigate economic loss.…”