Recently, there has been considerable interest in using 4-methylumbelliferone (4-MU) to inhibit hyaluronan synthesis in mouse models of cancer, autoimmunity, and a variety of other inflammatory disorders where hyaluronan (HA) has been implicated in disease pathogenesis. In order to facilitate future studies in this area, we have examined the dosing, treatment route, treatment duration, and metabolism of 4-MU in both C57BL/6 and BALB/c mice. Mice fed chow containing 5% 4-MU, a dose calculated to deliver 250 mg/mouse/day, initially lose substantial weight but typically resume normal weight gain after one week. It also takes up to a week to see a reduction in serum HA in these animals, indicating that at least a one-week loading period on the drug is required for most protocols. At steady state, over 90% of the drug is present in plasma as the glucuronidated metabolite 4-methylumbelliferyl glucuronide (4-MUG), with the sulfated metabolite, 4-methylumbelliferyl sulfate (4-MUS) comprising most of the remainder. Chow containing 5% but not 0.65% 4-MU was effective at preventing disease in the experimental autoimmune encephalomyelitis (EAE) mouse model of multiple sclerosis as well as in the DORmO mouse model of autoimmune diabetes. While oral 4-MU was effective at preventing EAE, daily intraperitoneal injections of 4-MU were not. Factors potentially affecting 4-MU uptake and plasma concentrations in mice include its taste, short half-life and low bioavailability. These studies provide a practical resource for implementing oral 4-MU treatment protocols in mice. This article is protected by copyright. All rights reserved.
View details for DOI 10.1111/cei.12815
View details for PubMedID 27218304