Role of natural P-gp inhibitor in the effective delivery for chemotherapeutic agents.

Multi-drug resistance has shown to be one of the leading threats faced currently in many chemotherapeutic agents. Permeability glycoprotein (P-gp) is an efflux transporter in membrane, an integral part of ATP-binding cassette (ABC) transporters widely distributed in the body for cellular uptake. It is present enormously in cancerous cells and is in charge of generating transporter mediated resistance to treatments of tumorous cells in addition to blocking the entry of chemotherapeutic drugs into the cell. Natural P-gp inhibitors are derived from natural plant sources possessing basic structures like alkaloids, flavonoids, phenolics, terpenoids, saponins, sapogenins, sterols, coumarins and miscellaneous structures acting on P-gp substrate for inhibition of multi-drug resistance via inhibiting the efflux pump. They do not depict their action on the healthy cells and thus it is proven to be more effective and less toxic than synthetic P-gp inhibitor leading to enhancement in bioavailability of chemotherapeutic drugs. The significant objective of the present review is surfing through the impact of natural P-gp inhibitors having basic structures derived from the plant sources and how it inhibits the resistance of chemotherapeutic drugs together with how well it delivers chemotherapy medicines.