PXR, also known as pregnane X receptor, is a nuclear receptor protein that plays a crucial role in the regulation of drug metabolism and detoxification in humans. It belongs to the nuclear receptor superfamily and is primarily expressed in the liver and intestine.
The main function of PXR is to act as a transcription factor, meaning it binds to specific DNA sequences, known as response elements, in the promoter regions of target genes. Upon binding, PXR can activate or repress the transcription of these target genes, thereby influencing various physiological processes.
PXR is especially involved in the metabolism of xenobiotics, which refers to foreign substances found in the body such as drugs, environmental pollutants, and dietary compounds. When xenobiotics enter the body, they are often metabolized by enzymes, and PXR is responsible for inducing the expression of these enzymes. By doing so, PXR helps to enhance the clearance and elimination of harmful substances from the body.
Furthermore, PXR is also known to have an impact on the expression of drug transporters, which are proteins involved in the entry and exit of drugs into and out of cells. By regulating the expression of drug transporters, PXR can influence the absorption, distribution, and excretion of drugs in the body, thereby affecting their therapeutic efficacy and potential toxicity.
Overall, the pivotal role of PXR in drug metabolism and detoxification pathways highlights its significance in human health and the potential for therapeutic interventions targeting this receptor for the treatment of various diseases.
