Quercetin as an Antiviral Agent Inhibits Influenza A Virus (IAV) Entry.

Wenjiao Wu, Richan Li, Xianglian Li, Jian He, Shibo Jiang, Shuwen Liu, Jie Yang

Journal: Viruses 2016;8(1):6

PMID: 26712783

Plain Language Summary

This mechanism study examines the role of quercetin at inhibiting influenza infection. Inﬂuenza A viruses (IAVs) are responsible for seasonal global pandemics and mortality, and genetic variations make it almost impossible to develop timely vaccines. Novel therapeutic strategies are anti-influenza agents are therefore of great interest. Two classes of anti-influenza drugs are widely used to inhibit viral entry and development, with varying side effects reported. Targeting viral entry and suppression of the infection at its early stage is an attractive therapeutic strategy. Quercetin is known to have anti-viral effects, alongside antioxidant, antibacterial and antiproliferation properties. Cells were infected with different influenza strains and exposed to quercetin, and the cytopathic effect and inhibition rates were measured at intervals. The results showed quercetin reduced transcription in inﬂuenza-virus-infected cells in a dose-dependent manner. This implies that quercetin’s mechanism of action may inhibit influenza in the early stage of viral attachment. Additional experiments found that quercetin directly targets the viral hemagglutinin protein particles rather than the host cells. The study concludes that quercetin possesses interesting anti-inﬂuenza activities which could be developed as a future therapeutic option for the therapy and prophylaxis of IAV infection.

Abstract

Influenza A viruses (IAVs) cause seasonal pandemics and epidemics with high morbidity and mortality, which calls for effective anti-IAV agents. The glycoprotein hemagglutinin of influenza virus plays a crucial role in the initial stage of virus infection, making it a potential target for anti-influenza therapeutics development. Here we found that quercetin inhibited influenza infection with a wide spectrum of strains, including A/Puerto Rico/8/34 (H1N1), A/FM-1/47/1 (H1N1), and A/Aichi/2/68 (H3N2) with half maximal inhibitory concentration (IC50) of 7.756 ± 1.097, 6.225 ± 0.467, and 2.738 ± 1.931 μg/mL, respectively. Mechanism studies identified that quercetin showed interaction with the HA2 subunit. Moreover, quercetin could inhibit the entry of the H5N1 virus using the pseudovirus-based drug screening system. This study indicates that quercetin showing inhibitory activity in the early stage of influenza infection provides a future therapeutic option to develop effective, safe and affordable natural products for the treatment and prophylaxis of IAV infections.

Address: State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China. [email protected].; State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China. [email protected].; State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China. [email protected].; State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China. [email protected].; Lindsley F. Kimball Research Institute, New York Blood Center, New York, NY 10065, USA. [email protected].; Key Lab of Medical Molecular Virology of Ministries of Education and Health, Shanghai Medical College, Fudan University, Shanghai 200032, China. [email protected].; State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China. [email protected].; State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China. [email protected].; Lindsley F. Kimball Research Institute, New York Blood Center, New York, NY 10065, USA. [email protected].

DOI: 10.3390/v8010006