Time-Dependent Inhibition of hOAT1 and hOAT3 by Anthraquinones

Abstract

We previously showed that anthraquinones (including rhein, emodin, aloe-emodin, chrysophanol and physcion) were inhibitors of human organic anion transporter 1 (hOAT1) and hOAT3, causing transporter-mediated drug-drug interactions in rats. In this study, the time-dependent inhibition (TDI) of hOAT1 and hOAT3 by anthraquinones was investigated. Madin-Darby canine kidney (MDCK)-hOAT1, HEK293-hOAT3 and their parental cells were used. Preincubation with chrysophanol or physcion for 30 min significantly increased the inhibition of hOAT1, but preincubation with rhein, emodin, aloe-emodin or probenecid had no effect on hOAT1 activity. By contrast, preincubation of hOAT3 with emodin, aloe-emodin, chrysophanol or physcion for 30 min significantly increased its inhibition, but preincubation with rhein or probenecid had no effect on activity. As the incubating time lengthened, from 0 to 60 min, both the inhibition of hOAT1 by chrysophanol and physcion and the inhibition of hOAT3 by emodin, aloe-emodin, chrysophanol and physcion were observed to increase in a time-dependent manner. In conclusion, our results suggest that some anthraquinones contribute to the TDI of hOAT1 and hOAT3. An inhibition study without the preincubation procedure may underestimate the inhibitory potential of anthraquinones against hOAT1 and hOAT3. The underlying mechanisms of TDI of hOAT1 and hOAT3 need to be further investigated. Key words organic anion transporter; anthraquinone; timedependent inhibitionIn CYP450 enzyme-mediated metabolism, time-dependent inhibition (TDI) has attracted significant attention. TDI of CYP450 enzymes refers to a change in the inhibitory potency during an in vitro incubation or dosing period in vivo. 1)However, does drug transporter-based TDI exist? Amundsen et al.2) reported that inhibition of organic anion transporting polypeptide 1B1 (OATP1B1) by cyclosporine A occurred in a time-dependent manner. Preincubation of OATP1B1 with cyclosporine A increased the inhibition of this protein; however, the underlying mechanism was not described in that report. Other researchers found that preincubation of OATP2B1 with apple juice or orange juice increased their inhibition effect.3)In general, there are very few articles that report on drug transporter-based TDI.In our previous study, we found that anthraquinones (rhein, emodin, aloe-emodin, chysophanol or physcion) inhibited human organic anion transporter 1 (hOAT1) and hOAT3. 4)Anthraquinones were coincubated with substrates of hOAT1 or hOAT3 in that study. However, we observed that preincubation of hOAT1 and hOAT3 with some of the anthraquinones increased hOAT1 and hOAT3 inhibition. Currently, TDI of the OATs family has not been studied. Therefore, in this study, the inhibitory effect of preincubation anthraquinones with hOAT1 and hOAT3 was investigated. The results provide evidence for the complex inhibitory mechanisms of drug transporters.

Chrysophanol: a review of its pharmacology, toxicity and pharmacokinetics

“…In addition, there were toxic metabolites by naphthalene and anthraquinone bioactivation pathways . Chrysophanol exhibited significant time‐dependent inhibition for human organic anion transporter 1 (hOAT1), hOAT3 and hOAT4 in 0–60 min …”

“…[80] Chrysophanol exhibited significant time-dependent inhibition for human organic anion transporter 1 (hOAT1), hOAT3 and hOAT4 in 0-60 min. [81] Pharmacokinetics Researcher found that the accumulation of chrysophanol in Caco-2 cells was four times higher than emodin, which may be related to the structure of chrysophanol and emodin and the specific transport system. [82] The main metabolic pathway of the bound anthraquinones was the hydrolysis of the glycosidic group followed by hydrogenation of the quinone moiety or further acetylation.…”

A Systematic In Vitro Investigation of the Inhibitor Preincubation Effect on Multiple Classes of Clinically Relevant Transporters

“…Early evidence for this came from studies in which the inhibitory effect of a single dose of CsA on the hepatic clearance of bromsulphthalein persisted for at least 3 days in rats (Shitara et al, 2009), and preincubation before coincubation of OATP1B1 with CsA, compared with coincubation only, resulted in up to a 20-fold reduction in the measured IC 50 values (Amundsen et al, 2010;Shitara et al, 2012). Recent literature indicates that additional compounds, including ritonavir, saquinavir, and anthraquinones, can exert a more potent inhibition of uptake transport activity upon preincubation (Amundsen et al, 2010;Shitara et al, 2013;Ma et al, 2015;Shitara and Sugiyama, 2017).…”

“…Most studies concerning PTIP have focused on OATPs, prompting regulatory agencies to recommend the inclusion of a preincubation step when OATP transport inhibition is being examined. Although sporadic studies have addressed the effect of preincubation on OATs (Ma et al, 2015) and OCTs (Arakawa et al, 2017), the lack of a systematic examination of non-OATP transporters has limited our knowledge of whether such mechanisms may be of additional clinical relevance.…”

Renal drug transporters and their significance in drug–drug interactions

“…While the plasma concentrations of the inhibitor drug are used for DDI prediction, the actual concentrations of inhibitor that the transporter encounters at the site of inhibition may be significantly different and difficult to measure. Lastly, substrate-dependent and time-dependent inhibitions have been recently reported 136 , 137 , 138 , 139 , which further complicates the assessment and in vitro –to– in vivo prediction of DDIs. Nevertheless, the field of drug transporters is rapidly evolving.…”