Chronic treatment with ivermectin changes drug disposition in mice - PowerPoint PPT Presentation

10th French-Belgian ABC meeting Brussels, Belgium, October 19-20, 2012 Chronic treatment with ivermectin changes drug disposition in mice through modulation of metabolism gene expression Mélanie Albérich , Cécile Ménez, Anne Lespine “Membrane Transporters and Resistance”, INRA ToxAlim unit, Toulouse, France

Macrocyclic Lactone Anthelmintics Ivermectin Human medicine Veterinary medicine Gastro intestinal nematodes Filarial nematode Onchocerca volvulus Very efficient low dose (0,2 mg/kg) + broad spectrum of activity Extensive use (…repeated dose) Emergence of resistant parasites

Substrate of ABC transporter P-glycoprotein (P-gp) (Shinckel et al, 1994) Metabolised by cytochromes P450 (Cyp) Human (Cyp3A), Rat (Cyp3A + 1A1) Ivermectin (Skalova et al, 2001) Drug concentration Drug efficacy in the organism

Ivermectin induces Pgp gene expression (Menez et al, 2012) In mamallian In cells cells Ivermectin-resistance increases ABC transporter genes expression (James and Davey, 2009) • Ppgs and MRPs in Caenorbaditis elegans (Yan et al, 2012) • Ppg9 in Teladorsagia circumcincta (J.Dicker et al, 2011) In nematodes • Ppg1 and Pgp9 in Haemonchus contortus (Williamson et al, 2011)

Ivermectin exposure of the host whole organism? Effect on the transport and biotransformation genes: ABC Transporter genes = abcb1a, abcb1b, abcc1, abcc2, abcc3, abcg2 Cytochrome P450 genes = Cyp1a2, Cyp2b10, Cyp3a11 Impact on drug disposition? 0,2 mg/kg ACUTE ADMINISTRATION � Gene expression in Single gavage intestine and liver by qRT ‐ PCR � Ivermectin concentration and CHRONIC ADMINISTRATION main metabolite in plasma, Reapeated gavage intestine, liver and brain by HPLC (Twice a week during 5 weeks)

Gene expression in the intestine after ivermectin exposure INTESTINE ACUTE TREATMENT 2,5 CHRONIC TREATMENT 9 (Fold induction relative to control) (Fold induction relative to control) * 8 ** *** 2 Gene expression level Gene expression levels * 7 6 1,5 * 5 4 1 3 Ivermectin and its main metabolite in organs 2 0,5 Ivermectin and its main metabolite in plasma PLASMA 1 A B 0 0 2,5 60 Ratio Metabolite/ Ivermectin in plasma (%) * IVM concentration in plasma (ng/ml) 50 2,0 40 1,5 * 30 1,0 20 0,5 10 0,0 0 ACUTE CHRONIC ACUTE CHRONIC TREATMENT TREATMENT TREATMENT TREATMENT

Ivermectin Chronic administration of ivermectin Main metabolite INTESTINAL P ‐ glycoprotein EPITHELIUM MRPs Cytochromes PLASMA CYP BLOOD CIRCULATION P ‐ gp INTESTINAL LUMEN LIVER Increases expression of gene of ABC transporters and cytochromes Ivermectin Main metabolite concentration rate

Long term exposure to ivermectin decreases ivermectin concentration in the host through regulation of metabolism gene ? Sub-lethal concentrations ? ? Selection of resistant parasites Decrease efficacy of other drug • Relates gene expression and protein (western, activity, Pgp inhibitors) • Study the synergism between Pgp and cytochrom: single and double KO • Impact of a long acting treatment with ivermectin in sheep

Membrane transporters and Resistance team Anne Lespine Cécile Menez Laurence Payrastre Chantal Lebrun Stéphane Orlowski Edwin Fouché Jean ‐ François Sutra Cécile Sotto