Fig. 7 The molecular mechanisms of PGS inhibits HBV replication. Cellular NF-κB and Raf/MEK/ERK signaling pathways are associated with the activation of innate immune system such as interferon system. PGS can bind and enter into HepG2.2.15 cells to activate the NF-κB and Raf/MEK/ERK pathways to enhance the interferon system, and indirectly suppress HBV transcription [42].