Inhibition of ganciclovir-resistant human cytomegalovirus replication by Kampo (Japanese herbal medicine).

We examined the effect of Kampo on the replication of ganciclovir (GCV)-resistant human cytomegalovirus (HCMV) in the human embryonic fibroblast cell line MRC-5. Treatment of HCMV-infected cells with Sho-seiryu-to (SST; Xiao-Qing-Long-Tang in Chinese) resulted in the inhibition of viral replication without affecting the cell growth. SST treatment decreased the synthesis of viral DNA, but had no virucidal effect on cell-free HCMV. However, the inhibitory effect of SST on HCMV replication was ablated by anti-interferon-beta (IFN-beta) antibody suggesting that SST inhibits the replication of GCV-resistant HCMV through the induction of IFN-beta. These results suggest that SST is a novel compund with potential as an anti-HCMV.