title: Sex-, Species-, and Tissue-Specific Metabolism of Empagliflozin in Male Mouse Kidney Forms an Unstable Hemiacetal Metabolite (M466/2) That Degrades to 4-Hydroxycrotonaldehyde, a Reactive and Cytotoxic Species.
abstract: Following oral administration of empagliflozin (1000 mg/kg/day) to male and female CD-1 mice for 2 years, renal tubular injury was identified in male mice. Renal injury was not detected in male mice (≤300 mg/kg/day), in female mice (1000 mg/kg/day), or in male or female Han Wistar rats (700 mg/kg/day). Using transfected HEK293 cells and Xenopus oocytes, empagliflozin was found to be a substrate of various mouse and rat organic anion transporters (oat/Oat) and organic anion transporting polypeptide (oatp/Oatp) transporters: mouse oat3, rat Oat3, mouse oatp1a1, and rat Oatp1a1. However, using isolated kidney slices from male and female mice and rats, no sex-based difference in the extent of uptake of empagliflozin occurred. Metabolism studies using hepatic and renal microsomes from male and female mice, rats, and humans revealed a hemiacetal metabolite of empagliflozin (M466/2), predominantly formed in male mouse kidney microsomes. Formation of M466/2 in male mouse kidney microsomes was 31-fold higher compared to that in female mouse kidney microsomes and was ∼29- and ∼20-fold higher compared to that in male and female mouse liver microsomes, respectively. M466/2 is unstable and degrades to form a phenol metabolite (M380/1) and 4-hydroxycrotonaldehyde (4-OH CTA). Formed 4-OH CTA was trapped by reduced GSH, and the structure of the GSH adduct was confirmed by mass spectrometry. Stoichiometric formation of M380/1 from M466/2 was observed (93-96% at 24 h); however, formation of 4-OH CTA was considerably lower (∼17.5% at 40 h), which is consistent with 4-OH CTA being a highly reactive species. These data represent a highly selective tissue-, species-, and sex-specific lesion in male CD-1 mice associated with a cytotoxic metabolite product, 4-OH CTA. In humans, glucuronidation of empagliflozin is the most prevalent metabolic pathway, and oxidation is a minor pathway. Thus, renal toxicity due to the formation of 4-OH CTA from empagliflozin is not expected in humans.
authors.affiliation: Drug Metabolism & Pharmacokinetics, Boehringer Ingelheim Pharmaceuticals, Inc. , Ridgefield, Connecticut 06877-0368, United States.
authors.forename: Mitchell E
authors.initials: ME
authors.lastname: Taub
authors.affiliation: Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany.
authors.forename: Eva
authors.initials: E
authors.lastname: Ludwig-Schwellinger
authors.affiliation: Pharmacokinetics and Non-Clinical Safety Department, Nippon Boehringer Ingelheim Co., Ltd. , Kobe, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Ishiguro
authors.affiliation: Pharmacokinetics and Non-Clinical Safety Department, Nippon Boehringer Ingelheim Co., Ltd. , Kobe, Japan.
authors.forename: Wataru
authors.initials: W
authors.lastname: Kishimoto
authors.affiliation: Drug Metabolism & Pharmacokinetics, Boehringer Ingelheim Pharmaceuticals, Inc. , Ridgefield, Connecticut 06877-0368, United States.
authors.forename: Hongbin
authors.initials: H
authors.lastname: Yu
authors.affiliation: Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Wagner
authors.affiliation: Drug Metabolism & Pharmacokinetics, Boehringer Ingelheim Pharmaceuticals, Inc. , Ridgefield, Connecticut 06877-0368, United States.
authors.forename: Donald
authors.initials: D
authors.lastname: Tweedie
mesh_terms: D000447:Aldehydes / Q000378:metabolism*; D000818:Animals; D001559:Benzhydryl Compounds / Q000378:metabolism*; D003603:Cytotoxins / Q000378:metabolism*; D005260:Female; D005960:Glucosides / Q000378:metabolism*; D057809:HEK293 Cells; D006801:Humans; D007004:Hypoglycemic Agents / Q000378:metabolism*; D007668:Kidney / Q000378:metabolism*; D007674:Kidney Diseases / Q000139:chemically induced / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D051379:Mice; D008861:Microsomes / Q000378:metabolism; D009865:Oocytes / Q000378:metabolism; D027361:Organic Anion Transporters / Q000378:metabolism; D017208:Rats, Wistar; D012737:Sex Factors; D013045:Species Specificity; D014982:Xenopus laevis
chemical_list: D000447:Aldehydes; D001559:Benzhydryl Compounds; D003603:Cytotoxins; D005960:Glucosides; D007004:Hypoglycemic Agents; D027361:Organic Anion Transporters; C042543:penitricin B; C570240:empagliflozin