Abstract
Rabies is a lethal infectious disease caused by rabies virus (RABV). The
mortality rate is very high after the appearance of clinical symptoms,
with a survival rate of almost 0%. There is presently no cure for
rabies. In the present study, we investigated whether the extract of
Shougong powder-a calcium powder prepared from gecko that has
demonstrated immunomodulatory properties in mice-is an effective
treatment for rabies. The antiviral effects of the extract were
evaluated both in vitro and in vivo with the cytotoxicity and antiviral
assays and by immunofluorescence analysis, quantitative real-time
(qRT)-PCR, and western blotting. The results showed that Shougong powder
and its extract increased survival rate in RABV-infected mice is up to
60% and 50% respectively, even in 20 times of LD50. Whereas the
control groups treated with Isoprinosine (IPS) or saline are only 20%
and 0% survival (P=0.011). qRT-PCR and western blot analyses showed
that the extract strongly inhibited viral mRNA expression and protein
synthesis in vitro: expression of the N, P, M, G, and L genes of RABV
was decreased by 28.8%–45.0% in the IPS group (P<0.05) and
by 50.1%–59.0% in the extract group (P<0.05) relative to
the control group. These results demonstrate that Shougong powder has
antiviral effects against RABV and can potentially be used for the
treatment for rabies.