Effects of novel 5-lipoxygenase inhibitors on the incidence of pulmonary adenomas in the A/J murine model when administered via nose-only inhalation.

Abstract

The objective of this study was to determine the effects of 5-lipoxygenase (5-LO) inhibitors on the incidence of benzo(a)pyrene-induced pulmonary adenomas in female A/J mice. Two novel compounds, S-29606 and S-30621, and the Food and Drug Administration-approved Zileuton were investigated. S-29606 and S-30621 were selected from a group of similar active structures on the basis of local versus systemic 5-LO inhibitory activity. Preliminary studies found them to lack oral bioavailability, in direct contrast to Zileuton. Treatment was initiated 1 week following exposure to the carcinogen benzo(a)pyrene. Both S-29606 and S-30621 were dosed via nose-only inhalation 5 days a week, for 16 weeks, whereas Zileuton was administered orally. Dose levels for S-29606 and S-30621 were determined to be 220 and 430 microg/kg for the low- and high-dose groups, respectively, whereas the dose of Zileuton was 245 mg/kg. Both test compounds exhibited a significant reduction of pulmonary adenomas, compared with a positive control for high and low doses, P < 0.05. Additionally, a dose response for both S-29606 and S-30621 was observed when compared with placebo. Despite a dose 575 times greater than that of the novel test compounds, orally administered Zileuton did not produce a reduction in adenoma occurrence. The findings of this study offer compelling preliminary data for the use of S-29606 and S-30621 in further investigations of the treatment of pulmonary adenomas and support the use of inhalation drug delivery as an alternate to oral delivery for these compounds.

• Authors: P B Myrdal, K Karlage, P J Kuehl, B S Angersbach, B A Merrill, P D Wightman
• Journal: Carcinogenesis (Carcinogenesis) Vol. 28 Issue 5 Pg. 957-61 (May 2007) ISSN: 0143-3334 [Print] England
• PMID: 17114645 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Hydroxamic Acids
• Lipoxygenase Inhibitors
• Phenylurea Compounds
• S 29606
• S 30621
• Benzo(a)pyrene
• zileuton
• Hydroxyurea

Topics

• Adenoma (chemically induced, prevention & control)
• Administration, Inhalation
• Administration, Oral
• Animals
• Benzo(a)pyrene
• Disease Models, Animal
• Dose-Response Relationship, Drug
• Female
• Hydroxamic Acids (pharmacology)
• Hydroxyurea (analogs & derivatives, pharmacology)
• Incidence
• Lipoxygenase Inhibitors (administration & dosage, pharmacology)
• Lung Neoplasms (chemically induced, prevention & control)
• Mice
• Mice, Inbred Strains
• Phenylurea Compounds (pharmacology)