Effect of Novel Formulations using Lipophilic Epigallocatechin-3-Gallate against Influenza Virus Infection

Abstract

Influenza virus infection is associated with high morbidity and mortality, and effective prophylactic and therapeutic methods to reduce infection outbreaks are lacking. Vaccination and current prevention/treatment approaches are not associated with a decline in morbidity or mortality, either globally or in the United States. Neither vaccination nor current anti-viral drugs prevent viral entry into the body and host cells, but rather target post-infection events in individuals. Hand washing and sanitizing do not prevent aerosol viral transmission, which accounts for the majority of influenza virus infections. Therefore, protection of the epithelia of the respiratory tract from viral entry is a significant gap in preventive strategies that needs to be filled. We hypothesize that lipophilic epigallocatechin3-gallate (L-EGCG), and EGCG-palmitate (EC16) in particular, is able to fill this gap and become a first-in-class prophylactic and therapeutic approach against influenza virus infection. The objective of the current study was to investigate a proof-of-concept for the use of EC16 to prevent and treat influenza virus infection. The experimental design included direct contact of formulations containing EC16 with H1N1 influenza virus prior to infection assay (TCID50) in MDCK cells, incubation of cells with EC16 formulations either before or after H1N1 viral infection (without direct formulation contact with the virus), and coating the cell surface with EC16 formulations prior to H1N1 viral infection, followed by TCID50 assays. The results demonstrated that at a 0.1% concentration, EC16 formulations were effective (>95%) in blocking H1N1 infection regardless of direct contact with the virus. In conclusion, formulations containing EC16 could be an effective prophylactic and therapeutic approach to combat influenza infection in the respiratory tract, pending further in vitro and in vivo studies.