Related Experiment Video
Updated: Jan 18, 2026
Early Viral Entry Assays for the Identification and Evaluation of Antiviral Compounds
Published on: October 29, 2015
Prunus mume Extract Inhibits SARS-CoV-2 and Influenza Virus Infection In Vitro by Directly Targeting Viral Particles
Mizuki Tokusanai1, Koichiro Tateishi1, Kanako Hirata1,2
1Department of Microbiology, Tokai University School of Medicine, 143 Shimokasuya, Isehara 259-1193, Kanagawa, Japan.
Abstract:
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza virus are major respiratory pathogens associated with substantial morbidity and a risk of severe disease. However, the effectiveness of current vaccines and antiviral drugs is limited by viral mutations. Umeboshi, a traditional Japanese food prepared from pickled Prunus mume, is known for its health benefits; certain components of P. mume have exhibited antimicrobial properties. However, the efficacy of P. mume against SARS-CoV-2 and influenza virus remains unknown. We aimed to examine the antiviral activity of P. mume extracts against SARS-CoV-2 and influenza virus. Cytopathic effect (CPE) assays and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analyses with full-time treatment demonstrated that four extracts (PM2, PM3, PM4, and PM6) among eight tested inhibited the replication of both viruses. Subsequent time-of-addition assays, plaque assays, and transmission electron microscopy (TEM) confirmed that PM2 directly inactivated viral particles of both viruses by disrupting their structural integrity. Additional evaluations of virion integrity and infectivity suggested that the antiviral activity of PM2 may also involve mechanisms other than direct virion disruption. These findings suggest that P. mume-derived components exhibit direct antiviral activities against SARS-CoV-2 and influenza virus, supporting their potential development as antiviral agents or infection-preventive dietary products.
Insights
Extracts from pickled plum (Prunus mume) showed direct antiviral activity against SARS-CoV-2 and influenza viruses. These findings support the development of Prunus mume components as potential antiviral agents or dietary products for infection prevention.
Area of Science:
- Virology
- Phytochemistry
- Infectious Diseases
Background:
- Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza virus cause significant respiratory illness.
- Viral mutations limit the effectiveness of current antiviral drugs and vaccines.
- Prunus mume (umeboshi) components possess known antimicrobial properties, but their efficacy against SARS-CoV-2 and influenza is unstudied.
Purpose of the Study:
- To investigate the antiviral activity of Prunus mume extracts against SARS-CoV-2 and influenza virus.
- To identify specific extracts with inhibitory effects on viral replication.
- To elucidate the mechanisms underlying the antiviral action of effective extracts.
Main Methods:
- Cytopathic effect (CPE) assays and RT-qPCR were used to screen eight Prunus mume extracts for antiviral activity.
- Time-of-addition assays, plaque assays, and transmission electron microscopy (TEM) were employed to confirm and characterize the antiviral mechanisms.
- Virion integrity and infectivity assays were conducted to further assess the mode of action.
Main Results:
- Four of eight tested Prunus mume extracts (PM2, PM3, PM4, and PM6) inhibited the replication of both SARS-CoV-2 and influenza virus.
- Extract PM2 demonstrated direct inactivation of viral particles by disrupting their structural integrity.
- Evidence suggests PM2's antiviral activity may involve additional mechanisms beyond direct virion disruption.
Conclusions:
- Prunus mume-derived components exhibit direct antiviral activity against SARS-CoV-2 and influenza viruses.
- Extract PM2 shows significant potential as a direct antiviral agent.
- These findings support the exploration of Prunus mume components for developing new antiviral therapies or preventative dietary products.
