RB1 and systemic lupus erythematosus: Ginsenoside Rb2, Rc, Rg2, Rg3, Rd and Rb1 exhibited highly polarized transport across Caco-2 cell monolayer with marked efflux ratio values at 4.42, 4.36, 4.26, 3.85, 4.47 and 3.77, respectively, which were far greater than 2.0, and the presence of SLE could concentration dependently decrease the transport capability of ginsenoside Rb2, Rc, Rg2, Rg3, Rd and Rb1 across Caco-2 monolayer in the BL-AP direction, which correspondingly led to the decrease in efflux ratios (As shown in Figure 5(A)).