Regarding the positive or negative modulatory effect of extracts and their components over P-gp, a study using Hypericum perforatum (Saint John’s wort) methanol extract (300 μg/mL) and one of its main components, hypericin (3 μM), showed induction of P-gp expression in LS180 cells (Dukes’ type B colorectal adenocarcinoma), while in Caco-2 cells P-gp activity was mildly inhibited [93], suggesting that the modulatory effect is dependent on the used cell model. Here, PGP is linked to colorectal adenocarcinoma.