PGP and lung carcinoma: To evaluate the P-gp inhibition potential of HM, we incubated A549 taxol-resistant human lung cancer cells and ABCB1 overexpressing U-87 MG cell lines with increasing concentrations of HM (12.5, 25, 50, 100, and 500 nM) prepared with either PVP-HM or cyclodextrin-HM; verapamil (10 μM) served as the positive control.