Quantum Chemical and Docking Insights into Bioavailability Enhancement of Curcumin by Piperine in Pepper.
We combine quantum chemical and molecular docking techniques to provide new insights into how piperine molecule in various forms of pepper enhances bioavailability of a number of drugs including curcumin in turmeric for which it increases its bioavailability by a 20-fold. We have carried out docking studies of quantum chemically optimized piperine structure binding to curcumin, CYP3A4 in cytochrome P450, p-Glycoprotein and UDP-glucuronosyltransferase (UGT), the enzyme responsible for glucuronosylation, which increases the solubility of curcumin. All of these studies establish that piperine binds to multiple sites on the enzymes and also intercalates with curcumin forming a hydrogen bonded complex with curcumin. The conjugated network of double bonds and the presence of multiple charge centers of piperine offer optimal binding sites for piperine to bind to enzymes such as UDP-GDH, UGT, and CYP3A4. Piperine competes for curcumin's intermolecular hydrogen bonding and its stacking propensity by hydrogen bonding with enolic proton of curcumin. This facilitates its metabolic transport, thereby increasing its bioavailability both through intercalation into curcumin layers through intermolecular hydrogen bonding, and by inhibiting enzymes that cause glucuronosylation of curcumin.
School of Pharmacy, Bharat Institute of Technology , Partapur, Meerut 250 103, Uttar Pradesh, India.
Vaishali M
VM
Patil
Discipline of Pharmacology, School of Medicine, The University of Adelaide , Adelaide, South Australia 5005, Australia.
Sukanya
S
Das
School of Molecular Sciences, Arizona State University , Tempe, Arizona 85287-1604, United States.
Krishnan
K
Balasubramanian
D000470:Alkaloids / Q000737:chemistry*; D052117:Benzodioxoles / Q000737:chemistry*; D001682:Biological Availability; D003474:Curcumin / Q000737:chemistry* / Q000378:metabolism / Q000493:pharmacokinetics*; D055808:Drug Discovery; D062105:Molecular Docking Simulation; D031701:Piper / Q000737:chemistry*; D010880:Piperidines / Q000737:chemistry*; D053284:Polyunsaturated Alkamides / Q000737:chemistry*; D011487:Protein Conformation; D011789:Quantum Theory
D000470:Alkaloids; D052117:Benzodioxoles; D010880:Piperidines; D053284:Polyunsaturated Alkamides; D003474:Curcumin; C008922:piperine