Preparation

Piperine is commercially available. If desired, it may be extracted from black pepper using dichloromethane. The amount of piperine varies from 1-2% in long pepper, to 5-9% in the white and the black peppers of commerce. Further, it may be prepared by treating the solvent-free residue from an alcoholic extract of black pepper, with a solution of sodium hydroxide to remove resin (said to contain chavicine, an isomer of piperine) and solution of the washed, insoluble residue in warm alcohol, from which the alkaloid crystallises on cooling.

Biological activity

The pungency caused by capsaicin and piperine is caused by activation of the heat and acidity sensing TRPV ion channel TRPV1 on nociceptors (pain sensing nerve cells).

Piperine has also been found to inhibit human CYP3A4 and P-glycoprotein, enzymes important for the metabolism and transport of xenobiotics and metabolites. In animal studies, piperine also inhibited other enzymes important in drug metabolism. By inhibiting drug metabolism, piperine may increase the bioavailability of various compounds. Notably, piperine may enhance bioavailability of curcumin by 2000% in humans.