Inhibition of P-glycoprotein by HIV protease inhibitors increases intracellular accumulation of berberine in murine and human macrophages.
BACKGROUND
HIV protease inhibitor (PI)-induced inflammatory response in macrophages is a major risk factor for cardiovascular diseases. We have previously reported that berberine (BBR), a traditional herbal medicine, prevents HIV PI-induced inflammatory response through inhibiting endoplasmic reticulum (ER) stress in macrophages. We also found that HIV PIs significantly increased the intracellular concentrations of BBR in macrophages. However, the underlying mechanisms of HIV PI-induced BBR accumulation are unknown. This study examined the role of P-glycoprotein (P-gp) in HIV PI-mediated accumulation of BBR in macrophages.


RESULTS
Cultured mouse RAW264.7 macrophages, human THP-1-derived macrophages, Wild type MDCK (MDCK/WT) and human P-gp transfected (MDCK/P-gp) cells were used in this study. The intracellular concentration of BBR was determined by HPLC. The activity of P-gp was assessed by measuring digoxin and rhodamine 123 (Rh123) efflux. The interaction between P-gp and BBR or HIV PIs was predicated by Glide docking using Schrodinger program. The results indicate that P-gp contributed to the efflux of BBR in macrophages. HIV PIs significantly increased BBR concentrations in macrophages; however, BBR did not alter cellular HIV PI concentrations. Although HIV PIs did not affect P-gp expression, P-gp transport activities were significantly inhibited in HIV PI-treated macrophages. Furthermore, the molecular docking study suggests that both HIV PIs and BBR fit the binding pocket of P-gp, and HIV PIs may compete with BBR to bind P-gp.


CONCLUSIONS
HIV PIs increase the concentration of BBR by modulating the transport activity of P-gp in macrophages. Understanding the cellular mechanisms of potential drug-drug interactions is critical prior to applying successful combinational therapy in the clinic.
Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, Virginia, United States of America.
Weibin
W
Zha
Guangji
G
Wang
Weiren
W
Xu
Xuyuan
X
Liu
Yun
Y
Wang
Beth S
BS
Zha
Jian
J
Shi
Qijin
Q
Zhao
Phillip M
PM
Gerk
Elaine
E
Studer
Phillip B
PB
Hylemon
William M
WM
Pandak
Huiping
H
Zhou
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001599:Berberine / Q000494:pharmacology*; D001667:Binding, Competitive; D001692:Biological Transport / Q000187:drug effects; D002460:Cell Line; D002851:Chromatography, High Pressure Liquid; D004077:Digoxin; D004285:Dogs; D015870:Gene Expression / Q000187:drug effects; D017320:HIV Protease Inhibitors / Q000494:pharmacology*; D006801:Humans; D008264:Macrophages / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D061985:Madin Darby Canine Kidney Cells; D051379:Mice; D062105:Molecular Docking Simulation; D011485:Protein Binding; D020112:Rhodamine 123; D019438:Ritonavir / Q000494:pharmacology*
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D017320:HIV Protease Inhibitors; D001599:Berberine; D020112:Rhodamine 123; D004077:Digoxin; D019438:Ritonavir