The Effects of Traditional Chinese Medicine on P-Glycoprotein-Mediated Multidrug Resistance and Approaches for Studying the Herb-P-Glycoprotein Interactions.

As a member of the ATP-dependent membrane transport proteins, P-Glycoprotein (P-gp) is known to pump substrates out of cells using an ATP-dependent mechanism. The overexpression of P-gp in tumor cells reduces the intracellular drug concentrations, which decreases the efficacy of extensive antitumor drugs and leads to multidrug resistance (MDR) clinically. The combination of anticancer drugs with P-gp inhibitor has been an attractive and promising strategy to reverse MDR in cancer treatment. However, nonspecific or nonselective distribution of P-gp inhibitors to nontarget organs is one of the most fatal shortcomings in clinical application. Thus, there is an urgent need for effective and nontoxic MDR reversal agents, particularly in P-gp-mediated MDR. Traditional Chinese medicine (TCM) natural products may prove less toxic for use in P-gp inhibition to promote MDR reversal. P-gp modulatory effects have been previously demonstrated using selected TCM, including the flavonoid, alkaloid, terpenoid, coumarin, and quinonoid compounds, and some Chinese medicine extracts. Moreover, the approaches for screening active components from TCM are necessary, and these approaches face challenges. At present, the approaches to study the interaction between TCM and P-gp are divided into in vitro, in vivo, and in silico methods. This review will provide an overview and update on the role of TCM in overcoming P-gp-mediated MDR and the approaches to study the interaction between TCM and P-gp. SIGNIFICANCE STATEMENT: This review summarized some traditional Chinese medicines identified to have a modulatory effect on P-gp, including flavonoids, alkaloids, terpenoids, coumarins, quinonoid compounds, and some Chinese medicine extracts, and it introduced possible mechanisms. The approaches to study the interaction between TCM and P-gp are divided into in vitro, in vivo, and in silico methods.