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Aloe Vera Juice: IC 50 and Dual Mechanistic Inhibition of CYP3A4 and CYP2D6
Author(s) -
Djuv Ane,
Nilsen Odd Georg
Publication year - 2012
Publication title -
phytotherapy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.019
H-Index - 129
eISSN - 1099-1573
pISSN - 0951-418X
DOI - 10.1002/ptr.3564
Subject(s) - cyp3a4 , dextromethorphan , quinidine , pharmacology , chemistry , cyp2d6 , ketoconazole , enzyme , potency , ic50 , biochemistry , in vitro , cytochrome p450 , biology , microbiology and biotechnology , antifungal
The aim of this study was to evaluate the inhibitory potency (IC 50 values) of ethanol extracts of two commercially available aloe vera juice (AVJ) products, on CYP3A4 and CYP2D6 activities in vitro and to determine if such inhibitions could be mechanism‐based. Recombinant human CYP3A4 and CYP2D6 enzymes were used and the activities were expressed by the metabolism of testosterone and dextromethorphan with ketoconazole and quinidine as positive inhibitor controls, respectively. The formed metabolites were quantified by validated HPLC techniques. Time‐ and NADPH‐ dependent inhibition assays were performed to evaluate a possible mechanism‐based inhibition. One of the AVJ extracts showed about twice the inhibitory potency towards both CYP enzymes over the other with IC 50 values of 8.35 ± 0.72 and 12.5 ± 2.1 mg/mL for CYP3A4 and CYP2D6, respectively. The AVJ was found to exert both CYP mediated and non‐CYP mediated inhibition of both CYP3A4 and CYP2D6. This dual mechanistic inhibition, however, seems to be governed by different mechanisms for CYP3A4 and CYP2D6. Estimated IC 50 inhibition values indicate no major interference of AVJ with drug metabolism in man, but the dual mechanistic inhibition of both enzymes might be of clinical significance. Copyright © 2011 John Wiley & Sons, Ltd.