title: Pre-clinical evidence for altered absorption and biliary excretion of irinotecan (CPT-11) in combination with quercetin: possible contribution of P-glycoprotein.
abstract: P-glycoprotein (P-gp) is found to play a very significant role in intestinal and biliary transport of irinotecan and its active metabolite, SN-38. This makes P-gp inhibition a logical strategy for improving irinotecan's oral efficacy and reducing its toxicity. The objective of the present study was to identify the most suitable P-gp inhibitor, amongst various commonly used herbal components via in vitro screening; followed by determination of in vivo effects in rats. Caco-2 cell monolayers were used to investigate the influence of various components (quercetin, hesperitin, piperine, curcumin and naringenin) on the transport of irinotecan. The secretory transport (basolateral-to-apical) was significantly decreased by all components (p<0.05) except piperine. In the apical-to-basolateral transport, quercetin showed the highest absorptive permeability enhancement and P-gp interaction potential making it an appropriate candidate for further in vivo studies in female Wistar rats. Quercetin pre-treatment resulted in increased irinotecan C(max) and area under curve (AUC) with a concomitant decrease in t(max), plasma clearance and volume of distribution (p<0.05). The absolute bioavailability (F) of irinotecan control was 33%, which was increased to 43% (1.3 fold) by quercetin administration. The amounts of irinotecan and SN-38 eliminated in bile in control rats, is reduced to almost half when treated with quercetin. Our studies not only propose a safe approach for bioavailability enhancement and reducing toxicity of irinotecan by P-gp inhibition but in another way also reiterate the significance of elucidating herb-drug interactions for future insights.
authors.affiliation: Department of Pharmaceutics, Faculty of Pharmacy, Jamia Hamdard, Hamdard University, Hamdard Nagar, New Delhi 110062, India. dr.tripta@gmail.com
authors.forename: Tripta
authors.initials: T
authors.lastname: Bansal
authors.forename: Anshumali
authors.initials: A
authors.lastname: Awasthi
authors.forename: Manu
authors.initials: M
authors.lastname: Jaggi
authors.forename: Roop K
authors.initials: RK
authors.lastname: Khar
authors.forename: Sushama
authors.initials: S
authors.lastname: Talegaonkar
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000009:adverse effects / Q000493:pharmacokinetics*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000493:pharmacokinetics; D000975:Antioxidants / Q000493:pharmacokinetics*; D001646:Bile / Q000378:metabolism*; D001682:Biological Availability; D001692:Biological Transport / Q000187:drug effects; D018938:Caco-2 Cells; D002166:Camptothecin / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D004354:Drug Screening Assays, Antitumor / Q000379:methods; D005260:Female; D006801:Humans; D007408:Intestinal Absorption / Q000187:drug effects*; D000077146:Irinotecan; D011794:Quercetin / Q000493:pharmacokinetics*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000972:Antineoplastic Agents, Phytogenic; D000975:Antioxidants; D000077146:Irinotecan; D011794:Quercetin; D002166:Camptothecin