Final answer:
The question focuses on P-glycoprotein, a protein that can be induced or inhibited by various substances, impacting drug absorption and drug-drug interactions. Certain antiepileptic drugs and St. John's Wort induce P-glycoprotein, increasing drug efflux, while some antibiotics and antiarrhythmic drugs inhibit it, decreasing efflux.
Step-by-step explanation:
The question pertains to P-glycoprotein (PgP), a membrane protein that acts as an efflux transporter, influencing the absorption and distribution of drugs in the body. Specifically, it inquires about the substances that can induce or inhibit P-glycoprotein's function, which is crucial for evaluating drug-drug interaction potential during drug discovery. Inducers of P-glycoprotein, like certain antiepileptic drugs and extracts from St. John's Wort, may reduce the effectiveness of drugs that are substrates of PgP by increasing their efflux out of cells. Conversely, inhibitors, including some antibiotics or antiarrhythmic drugs, can enhance the action of PgP substrates by decreasing their efflux. However, flavonoids present in citrus fruit are typically not inhibitors of P-glycoprotein; rather, they could potentially act as inducers. To evaluate the transport via PgP efficiently, in vitro studies such as those using a Using chamber with a mouse intestine membrane can help identify whether specific new chemical entities (NCEs) are substrates or inhibitors of the intestinal efflux transporter PgP.