In vitro and in vivo profiling of CHF5022 and CHF5074: Two β-amyloid 1–42 lowering agents

Abstract

Long-term use of non-steroidal anti-inflammatory drugs (NSAIDs) may delay or prevent the onset of Alzheimer's disease (AD). A subset of NSAIDs, including flurbiprofen, has been shown to selectively inhibit the production of β-amyloid 1–42 (Aβ42), independently from their cyclooxygenase (COX) inhibiting activity. We evaluated the in vitro and in vivo profiles of CHF5022 and CHF5074, two flurbiprofen analogues. The in vitro Aβ inhibiting activity was evaluated in a human neuroglioma cell line (H4) carrying the double Swedish mutation (K595N/M596L) of the human amyloid precursor protein (APPsw). The in vitro anti-COX activity was evaluated using human recombinant enzymes isolated from transfected Sf-9 cells. The in vivo pharmacokinetic and pharmacodynamic profiles of the two compounds were evaluated in young APPsw transgenic mice (Tg2576) after oral gavage (100 or 300 mg kg −1 day −1 for 4–5 days) and after medicated diet (375 ppm for 4 weeks). R-Flurbiprofen was used as comparator. In vitro, CHF5022 and CHF5074 were found to be 3- and 7-fold more potent than R-flurbiprofen in inhibiting Aβ42 secretion (IC 50s of 92, 40 and 268 μM, respectively). Differently from R-flurbiprofen, CHF5022 and CHF5074 did not affect COX-1 (at 100 μM) and COX-2 (at 300 μM) activity. Similarly to R-flurbiprofen, no significant alteration in the expression profile of a subset of Notch intracellular domain-responsive genes was observed with either CHF5022 or CHF5074. In Tg2576 mice, CHF5022 was well tolerated when administered by oral gavage (100 mg kg −1 day −1 for 5 days) or by medicated diet (56 mg kg −1 day −1 for 4 weeks). R-Flurbiprofen was poorly tolerated in the diet (32 mg kg −1 day −1) with 55% of the animals dying during the first week of treatment. After 4–5 days of oral gavage, CHF5022 and CHF5074 plasma and brain levels at 3 h were found to increase with the dose, leading to brain concentrations of about 10% and 5% of the corresponding plasma concentrations, respectively. In animals fed for 4 weeks with compound-supplemented diet, mean plasma (580 μM) and brain (20 μМ) concentrations of CHF5022 were 8 and 15 times higher than those of R-flurbiprofen. Plasma Aβ42 concentration was dose-dependently decreased by CHF5022 and CHF5074. Brain Aβ levels (formic acid-extractable) were not significantly affected by either compound, although Aβ42 levels tended to inversely correlate ( P = 0.105) with CHF5022 concentration in the brain. CHF5022 and CHF5074 thus appear to have a promising in vitro and in vivo profile. This warrants further evaluation of their long-term effects on Aβ brain pathology.