Effects of COX1-2/5-LOX blockade in Alzheimer transgenic 3xTg-AD mice.

OBJECTIVE AND DESIGN: Alzheimer's disease (AD) is associated with amyloid plaques (Aβ) and hyperphosphorylated tau protein tangles in the brain. We investigated the possible neuroprotective role of flavocoxid, a dual inhibitor of cyclooxygenases-1/2 (COX-1/2) and 5-Lipoxygenase (5-LOX), in triple-transgenic (3xTg-AD) mice.

SUBJECTS: Mice were 3 months at the beginning of the study.

TREATMENT: Animals received once daily for 3-month saline solution or flavocoxid (20 mg/kg/ip).

METHODS: Morris water maze was used to assess learning and memory. Histology was performed to evidence Aβ plaques and neuronal loss, while inflammatory proteins were determined by western blot analysis.

RESULTS: Saline-treated 3xTg-AD mice showed an impairment in spatial learning and memory (assessed at 6 months of age), and increased expression of inflammatory and apoptotic molecules. Treatment of 3xTg-AD mice with flavocoxid reduced: (1) learning and memory loss; (2) the increased eicosanoid production and the phosphorylation level of amyloid precursor protein (APP-pThr668), Aβ 1-42, p-tau (pThr181), pERK, and the activation of the NLRP3 inflammasome; (3) Aβ plaques; and (4) neuronal loss, compared to saline-treated animals.

CONCLUSIONS: Pharmacological blockade of both COX-1/2 and 5-LOX was able to counteract the progression of AD by targeting pathophysiological mechanisms up- and downstream of Aβ and tau.