Fig. 7 in A previously undescribed phenylethanoid glycoside from Callicarpa kwangtungensis Chun acts as an agonist of the Na/K-ATPase signal transduction pathway

Fig. 7. The relative binding affinity of callicarpanoside B compared with ouabain. The 3H-ouabain binding assay was utilized to determine the relative binding affinity. After preincubation with non-radioactive ouabain or callicarpanoside B to NKA for 30 min in cultured LLC-PK1 cells, 100 nM 3H-ouabain were added and incubated another 30 min. Thus, the IC50 for binding nonradioactive ouabain or callicarpanoside B to NKA was determined by competition with 3H-ouabain. The data are combined from three experiments and are presented as mean ± SD. Non-radioactive ouabain, IC50 = 0.95 ± 0.35 μM; callicarpanoside B, IC50 = 10.55 ± 3.05 μM.