In Vivo Inhibition Profile of CYP2C9 by Pineapple Juice

NCT ID: NCT01649492

Last Updated: 2012-07-25

Basic Information

• Recruitment Status: UNKNOWN
• Clinical Phase: PHASE4
• Total Enrollment: 10 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2012-09-30
• Study Completion Date: 2012-10-31

Brief Summary

The goal of this study is to evaluate the actual potential for in vivo pineapple juice inhibition with CYP2C9 substrates in human volunteers with use of diclofenac as a marker of CYP2C9 activity.

Detailed Description

For ovarian cancer, colorectal and gastric cancers presenting with peritoneal metastases, complete tumor removal at surgery is the most important independent prognostic factor. Consequently, accurate detection of tumors often compromising resectability, like extra-abdominal metastases, liver metastases, portal and superior mesenteric artery deposits and extensive intestinal serosal invasion is pivotal prior to treatment selection. Computed tomography (CT) has variable accuracy for staging, due to the difficult detection of low-contrast or small-sized peritoneal or nodal metastases. Fluorodeoxyglucose positron emission tomography/CT (FDG-PET/CT) improves detection of thoraco-abdominal lymphadenopathy and liver metastases, but inconsistently detects small (<5mm) peritoneal metastases. Therefore a diagnostic staging laparoscopy under general anesthesia is currently the necessary standard of clinical practice in addition to imaging for assessment of operability.

Whole body diffusion-weighted magnetic resonance imaging is researched at the department of radiology, University Hospitals Leuven in collaboration with the departments of abdominal surgery, oncologic surgery, oncologic gynaecology and digestive oncology. The technique holds high promise to combine a high accuracy in systemic thoraco-abdominal staging and peritoneal assessment of operability. Technological progress has enabled time-efficient WB-DWI with thin-slice-acquisition and multiplanar image reformatting. DWI depicts lesions by measuring water diffusion differences, correlating with cellular density. Tumors are depicted with high signal compared to background by combining a short-T1-inversion-time inversion recovery (STIR) prepulse - suppressing ascites, blood vessels, fat, bowel and visceral organs - and heavy diffusion weighting. However, due to contraction and mucosal cellularity, the bowel wall can show increased signal-intensity (SI), hampering the detection of serosal deposits. This is overcome by suppressing contractions by intravenous antispasmodic and by distending the bowel wall and suppressing the signal of bowel content by peroral pineapple juice which shows negative contrast properties due to the manganese-content. In a first pilot study in ovarian cancer at this center in 32 patients, an accuracy for detection of intestinal serosal metastases of 90% was reached by WB-DWI combined with peroral pineapple juice. As such, the pineapple juice plays a pivotal role as a peroral contrast in addition to WB-DWI for accurate peritoneal staging.

To date, the inhibitory potential of pineapple juice on cytochrome P450 2C9 activity has only been described in vitro in human microsomes. In this model, in which diclofenac and its metabolite 4-OH-diclofenac have been used as probes for CYP2C9 activity, it has been shown that pineapple juice is capable to inhibit CYP2C9 very potently (IC50 0.08%) in an irreversible manner. It has been suggested that the main effect is caused by bromelain, a 24-26 kDa cysteine protease enzyme present in pineapple juice. The intestinal absorption of intact bromelain after oral intake has been described in 19 healthy men, which is surprising as the adult intestinal epithelium has traditionally been described as non-permeable to proteins. The (limited) absorption is thought to occur via the paracellular route, which could explain that the catalytic activity bromelain is preserved following absorption into the blood circulation. Although no effects of bromelain on CYP2C9 activity are expected in vivo (due to low oral bioavailability), no in vivo trials have been undertaken to elucidate if pineapple juice, and more specifically bromelain, is capable of inhibiting intestinal and, more importantly, hepatic CYP2C9 in a clinically relevant manner.

The in vivo inhibitory profile of CYP2C9 by pineapple juice will be evaluated in this study in 10 healthy volunteers, by examining the impact on the area-under-the-curves (AUCs) of diclofenac and its metabolite 4-OH diclofenac.

Conditions

Healthy Volunteers

Keywords

diclofenac; CYP2C9; bromelain; pineapple juice

Study Design

• Allocation Method: NON_RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: NONE

Study Groups

diclofenac without pineapple juice

single dose of diclofenac 25 mg without pre-exposure to pineapple juice

Group Type: NO_INTERVENTION

No interventions assigned to this group

diclofenac with pineapple juice

single dose of diclofenac 25 mg with pre-exposure to pineapple juice

Group Type: ACTIVE_COMPARATOR

pineapple juice (Carrefour n°1) 500 ml/day 5 days

Intervention Type: DIETARY_SUPPLEMENT

Interventions

pineapple juice (Carrefour n°1) 500 ml/day 5 days

Intervention Type: DIETARY_SUPPLEMENT

Eligibility Criteria

Inclusion Criteria

• adult healthy volunteers

Exclusion Criteria

• younger than 18 yrs
• older than 60 yrs
• pregnant or lactating women
• medical history of gastric or duodenal ulcers, gastro-oesofageal reflux disease, dyspepsia, asthma, any allergy to NSAIDS
• patients taking co-medication

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 60 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Universitaire Ziekenhuizen KU Leuven

OTHER

Sponsor Role: lead

Responsible Party

Isabelle Spriet

PharmD, PhD

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Isabel Spriet, PharmD PhD

Role: PRINCIPAL_INVESTIGATOR

Pharmacy Dpt, University Hospitals Leuven

Hans Prenen, MD PhD

Role: STUDY_CHAIR

Digestive Oncology, University Hospitals Leuven

Vincent Vandecaveye, MD PhD

Role: STUDY_CHAIR

Radiology Dpt, University Hospitals Leuven

Pieter Annaert, PharmD PhD

Role: STUDY_CHAIR

Laboratory for Pharmacotechnology and Biopharmacy, Catholic University Leuven

Locations

University Hospitals Leuven

Leuven, , Belgium

Countries

Belgium

Central Contacts

Isabel Spriet, PharmD PhD

Role: CONTACT

Phone: 0032 16 34 30 80

Email: isabel.spriet@uzleuven.be

Pieter Annaert, PharmD PhD

Role: CONTACT

Phone: 0032 16 33 03 03

Email: pieter.annaert@pharm.kuleuven.be

Other Identifiers

S54465

Identifier Type: -

Identifier Source: org_study_id