Genotoxicity testing of peptides: Folate deprivation as a marker of exaggerated pharmacology

Journal Article · Mon Sep 15 04:00:00 EDT 2014 · Toxicology and Applied Pharmacology

DOI:https://doi.org/10.1016/J.TAAP.2014.06.022· OSTI ID:22439840

Guérard, Melanie; Zeller, Andreas; Festag, Matthias; Schubert, Christine; Singer, Thomas; Müller, Lutz

The incidence of micronucleated-cells is considered to be a marker of a genotoxic event and can be caused by direct- or indirect-DNA reactive mechanisms. In particular, small increases in the incidence of micronuclei, which are not associated with toxicity in the target tissue or any structurally altering properties of the compound, trigger the suspicion that an indirect mechanism could be at play. In a bone marrow micronucleus test of a synthetic peptide (a dual agonist of the GLP-1 and GIP receptors) that had been integrated into a regulatory 13-week repeat-dose toxicity study in the rat, small increases in the incidence of micronuclei had been observed, together with pronounced reductions in food intake and body weight gain. Because it is well established that folate plays a crucial role in maintaining genomic integrity and pronounced reductions in food intake and body weight gain were observed, folate levels were determined from plasma samples initially collected for toxicokinetic analytics. A dose-dependent decrease in plasma folate levels was evident after 4 weeks of treatment at the mid and high dose levels, persisted until the end of the treatment duration of 13-weeks and returned to baseline levels during the recovery period of 4 weeks. Based on these properties, and the fact that the compound tested (peptide) per se is not expected to reach the nucleus and cause DNA damage, the rationale is supported that the elevated incidence of micronucleated polychromatic erythrocytes is directly linked to the exaggerated pharmacology of the compound resulting in a decreased folate level. - Highlights: • A synthetic peptide has been evaluated for potential genotoxicity • Small increases in an integrated (13-weeks) micronucleus test were observed • Further, animals had a pronounced reductions in food intake and body weight gain • A dose-dependent decrease in plasma folate levels was evident from week 4 onwards • Elevated micronuclei-incidence due to the exaggerated pharmacology.

• OSTI ID: 22439840
• Journal Information: Toxicology and Applied Pharmacology, Journal Name: Toxicology and Applied Pharmacology Journal Issue: 3 Vol. 279; ISSN TXAPA9; ISSN 0041-008X
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
BONE MARROW
DNA
DNA DAMAGES
DOSES
ERYTHROCYTES
FOOD
GAIN
INTAKE
PEPTIDES
PHARMACOLOGY
RATS
RECEPTORS
REDUCTION
TOXICITY