Protective effect of Astragali Radix by intraperitoneal injection against Japanese encephalitis virus infection in mice.
We examined the protective effect of Astragali Radix extracts (AE) by intraperitoneal injection against Japanese encephalitis virus (JEV) infection in mice. A protective effect was observed by all four samples of AE used. However, the degree of effectiveness for each AE was different. The observed survival rates of the groups injected with sample A (from Shanhsi, Japanese name Sansei-syo) and sample D (from Hokkaido) extracts were higher than 80% at 21 d after JEV inoculation. The groups injected with sample B (from Hopei, Japanese name Kahoku-syo) and sample C (from Hsiahsi, Japanese name Sensei-syo) extracts had a 60% survival rate. The increase in hemagglutination inhibition antibody titer was negligible in mice that survived 21 d after JEV inoculation. The antiviral effect of AE was examined by plaque assay in vitro, but no antiviral effect was shown. In mice injected with AE, the peritoneal exudate cell (PEC) numbers increased significantly, compared to the control. In these PEC, active oxygen production was also high. Also the group as a whole displayed a high survival rate against JEV infection, these were so strong. From these results, we propose that the protective effect of AE is dependent on a non-specific mechanism during the early stage of infection, before it shifts to antibody production, and that PEC plays an important role.
Kajimura
K
K
Osaka Prefectural Institute of Public Health, Japan.
Takagi
Y
Y
Ueba
N
N
Yamasaki
K
K
Sakagami
Y
Y
Yokoyama
H
H
Yoneda
K
K
D000818:Animals; D000998:Antiviral Agents / Q000627:therapeutic use*; D001835:Body Weight / Q000187:drug effects; D002452:Cell Count; D002460:Cell Line / Q000187:drug effects / Q000821:virology; D004365:Drugs, Chinese Herbal / Q000627:therapeutic use*; D004664:Encephalitis Virus, Japanese / Q000187:drug effects / Q000276:immunology; D018792:Encephalitis, Viral / Q000188:drug therapy* / Q000401:mortality / Q000821:virology; D005122:Exudates and Transudates / Q000166:cytology / Q000187:drug effects; D006385:Hemagglutination Inhibition Tests; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D010529:Peritoneal Cavity / Q000166:cytology; D017382:Reactive Oxygen Species / Q000378:metabolism; D015996:Survival Rate
D000998:Antiviral Agents; D004365:Drugs, Chinese Herbal; D017382:Reactive Oxygen Species