Potentially Profound Fluctuation in Tacrolimus Concentration on the Consumption of Pomegranate: Computed by Lc-Ms/Ms and Md Simulation Studies

Presently, varied case reports demonstrated an increase or decrease in blood concentration of diverse conventional drugs, often co-administered with edible fruits, spices, or vegetables. The overarching aim of this research is to elucidate the fluctuations in tacrolimus (TAC) blood concentration on the consumption of pomegranate rind extract (PG). Pharmacokinetic (PK) study was conducted with two groups, viz-a-viz PG (200 mg/kg) + TAC (2mg/kg) and TAC (3mg/kg) alone group. For this, the PG (200 mg/kg) was given to the Wistar rats on day 0 and continued till 6 days. On the 7th day, respective doses of TAC were administered orally, in rats 1 hr after oral administration of the PG. All the blood samples (approximately 300 μl) were withdrawn at diverse time intervals i.e. 30 min, 1 hr, 2hr, 4hr, 8hr, and 12hr after oral administration of TAC. Estimation of TAC in rat plasma was done by using the hyphenated technique LC-MS/MS where the mass spectrometer used was triple-stage quadruple and using multiple reactions monitoring (MRM) mode. Findings depict that on comparison with TAC (3mg/kg) alone group, the Cmax was found to be 4.34±0.60 ng/ml; AUC from time zero to infinity (AUC0-∞), 31.58±1.47 ngh/ml, whilst TAC (2mg/kg)+ PG group exhibited an increase in PK parameters of TAC (Cmax 15.08±1.56 ng/ml; AUC0-∞69.38±3.68 ng h/ml). The authors further investigated in what manner the PG affects the PK of TAC in animals. For this, a CYP3A4 inhibitory assay was conducted, and to validate our findings, docking studies with selected phytoconstituents and CYP3A4 isoenzyme was carried out. Ellagitannins (dock score -11.64) and punicalagin (dock score -10.68) were again used for molecular simulation studies with TAC. Based on integrated in-vivo and in-silico studies, we concluded that punicalagin interacts strongly with CYP isoenzyme, and therefore responsible for the altered PK profile of TAC.