Inhibitory effect of three components derived from Salvia miltiorrhiza against human cytomegalovirus

Human cytomegalovirus (HCMV) infection is responsible for congenital infections and poses a significant health risk to immunocompromised individuals. To date, there is no effective HCMV vaccine. Salvia miltiorrhiza is a well-known traditional Chinese herb that possesses active pharmacological effects including antiviral activity. However, no studies on the effects of Salvia miltiorrhiza on HCMV have been reported thus far.

Firstly, the cytotoxicity of five active components derived from Salvia miltiorrhiza was screened, then morphology, western blotting, qPCR, indirect immunofluorescence assay (IFA) and TCID₅₀ assay were used to assess anti-HCMV activity. Time-of-addition experiments were performed to identify the stage at which the active components were active. The mechanism of the anti-HCMV activity of the active component was also illustrated in this study.

Salvianolic acid B, Tanshinone ⅡA, and Cryptotanshinone derived from Salvia miltiorrhiza were found to prevent lytic cytopathic changes, inhibit the expression of viral proteins, suppress the replication of HCMV DNA, and significantly reduce the viral titer in WI-38 cells. Time-of-addition experiments showed that they predominantly act during the Post-entry treatment (Post-T) stage. Moreover, they effectively suppressed HCMV-induced cellular senescence, which was evidenced by a decline in senescence-associated β-galactosidase activity, alleviated senescence-associated heterochromatin foci (SAHF), reduced expression of p16, p21, and p53, and decreased production of reactive oxygen species (ROS).

To our knowledge, this is the first report that salvianolic acid B, tanshinone IIA, and cryptotanshinone derived from Salvia miltiorrhiza exhibit anti-HCMV activity in vitro, and suggest potential for further development.