Mechanism of the antiviral effect of hydroxytyrosol on influenza virus appears to involve morphological change of the virus.
Hydroxytyrosol (HT), a small-molecule phenolic compound, inactivated influenza A viruses including H1N1, H3N2, H5N1, and H9N2 subtypes. HT also inactivated Newcastle disease virus but not bovine rotavirus, and fowl adenovirus, suggesting that the mechanism of the antiviral effect of HT might require the presence of a viral envelope. Pretreatment of MDCK cells with HT did not affect the propagation of H9N2 virus subsequently inoculated onto the cells, implying that HT targets the virus but not the host cell. H9N2 virus inactivated with HT retained unaltered hemagglutinating activity and bound to MDCK cells in a manner similar to untreated virus. Neuraminidase activity in the HT-treated virus also remained unchanged. However, in the cells inoculated with HT-inactivated H9N2 virus, neither viral mRNA nor viral protein was detected. Electron microscopic analysis revealed morphological abnormalities in the HT-treated H9N2 virus. Most structures found in the HT-treated virus were atypical of influenza virions, and localization of hemagglutinin was not necessarily confined on the virion surface. These observations suggest that the structure of H9N2 virus could be disrupted by HT.
Yamada
Kentaro
K
Research Center for Animal Hygiene and Food Safety, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan.
Ogawa
Haruko
H
Hara
Ayako
A
Yoshida
Yukio
Y
Yonezawa
Yutaka
Y
Karibe
Kazuji
K
Nghia
Vuong Bui
VB
Yoshimura
Hiroyuki
H
Yamamoto
Yu
Y
Yamada
Manabu
M
Nakamura
Kuniyasu
K
Imai
Kunitoshi
K
D000256:Adenoviridae / Q000187:drug effects; D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D002460:Cell Line; D003593:Cytoplasm / Q000648:ultrastructure; D004285:Dogs; D053118:Influenza A Virus, H1N1 Subtype / Q000187:drug effects; D053122:Influenza A Virus, H3N2 Subtype / Q000187:drug effects; D053124:Influenza A Virus, H5N1 Subtype / Q000187:drug effects; D053127:Influenza A Virus, H9N2 Subtype / Q000187:drug effects; D009980:Influenza A virus / Q000187:drug effects* / Q000648:ultrastructure*; D009522:Newcastle disease virus / Q000187:drug effects; D010626:Phenylethyl Alcohol / Q000031:analogs & derivatives* / Q000494:pharmacology; D012367:RNA, Viral / Q000096:biosynthesis; D012401:Rotavirus / Q000187:drug effects; D014764:Viral Proteins / Q000096:biosynthesis; D014771:Virion / Q000648:ultrastructure; D019065:Virus Assembly / Q000187:drug effects; D053585:Virus Attachment / Q000187:drug effects; D014779:Virus Replication / Q000187:drug effects
D000998:Antiviral Agents; D012367:RNA, Viral; D014764:Viral Proteins; C005975:3,4-dihydroxyphenylethanol; D010626:Phenylethyl Alcohol