Inhibitory effect of cinnamaldehyde, derived from Cinnamomi cortex, on the growth of influenza A/PR/8 virus in vitro and in vivo.
We have investigated the inhibitory effect of trans-cinnamaldehyde (CA), one of the principal constituents of essential oil derived from Cinnamomi cortex, on the growth of influenza A/PR/8 virus in vitro and in vivo. When 1-h drug treatment was initiated at various times post-infection (p.i.) in Madin-Darby canine kidney cells using a fixed dose of CA (40 microM), the maximum inhibitory effect (29.7% virus yield of control) was obtained when drug treatment was started at 3h p.i. Under the same treatment schedule, CA inhibited the virus growth in a dose-dependent manner (20-200 microM), and, at 200 microM, the virus yield was reduced to an undetectable level. RT-PCR and SDS-PAGE analyses showed that CA inhibited viral protein synthesis at the post-transcriptional level. In mice infected with the lung-adapted PR-8 virus, inhalation (50mg/cage/day) and nasal inoculation (250 microg/mouse/day) of CA significantly increased survival rates on the 8 days to 100% and 70%, respectively, in contrast to a survival rate of 20% in the untreated control group. Importantly, inhalation of CA caused virus yield reduction by 1 log in bronchoalveolar lavage fluid on day 6 after infection, compared with that of the untreated control group. These findings might provide further support to the empirical indication of Cinnamomi cortex-containing Kampo medicines for acute respiratory infectious diseases.
Hayashi
K
K
Department of Frontier Japanese Oriental (Kampo) Medicine, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chiba 260-8670, Japan.
Imanishi
N
N
Kashiwayama
Y
Y
Kawano
A
A
Terasawa
K
K
Shimada
Y
Y
Ochiai
H
H
D000171:Acrolein / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D000280:Administration, Inhalation; D000281:Administration, Intranasal; D000818:Animals; D000998:Antiviral Agents / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D001992:Bronchoalveolar Lavage Fluid / Q000821:virology; D002460:Cell Line; D002642:Chick Embryo; D027424:Cinnamomum / Q000737:chemistry*; D004305:Dose-Response Relationship, Drug; D005260:Female; D053118:Influenza A Virus, H1N1 Subtype / Q000187:drug effects* / Q000254:growth & development; D053122:Influenza A Virus, H3N2 Subtype / Q000187:drug effects / Q000254:growth & development; D009981:Influenza B virus / Q000187:drug effects / Q000254:growth & development; D051379:Mice; D008826:Microbial Sensitivity Tests; D009976:Orthomyxoviridae Infections / Q000188:drug therapy* / Q000821:virology; D014764:Viral Proteins / Q000096:biosynthesis / Q000187:drug effects
D000998:Antiviral Agents; D014764:Viral Proteins; D000171:Acrolein; C012843:cinnamaldehyde