Ginsenosides Rg1 and Re act as adjuvant via TLR4 signaling pathway

► Rg1 and Re have adjuvant activity in C3H/HeB mice, but not in C3H/HeJ mice. ► Rg1 and Re induce expression of NF-κB in macrophages. ► Blocking TLR4 on cells with anti-TLR4 IgG inhibits Re- but not Rg1-induced NF-κB. ► Rg1 triggers extra- and intra-cellular TLR4 while Re triggers extra-cellular TLR4. ► TLR4 is supposed to be involved in the adjuvant activities of Rg1 and Re.