Cell experiment:

BAEC are incubated for 30 min with Naproxen (0.1 ng/mL to 1 mg/mL). Arachidonic acid (30 μM) is then added, and the cells are incubated for a further 15 min at 37℃. The medium is then removed, and radioimmunoassay is used to measure the formation of 6-keto-PGF,a, PGE2, thromboxane B2, or PGF2a[1].

Animal experiment:

Rats[3]To measure the analgesic effects of naproxen in a carrageenaninduced model of monoarthritis, Male Sprague–Dawley rats (n=48, 217±28 g) are randomly divided into four groups of 12 by an internally developed computer program, allowing the blind performance of the behavioral experiment. To induce hyperalgesia by inflammation, animals in groups 1B, 1C, and 1D receive a 40-μL intra-articular injection of a saline solution containing 7.5 mg/mL carrageenan in the left hind limb under isoflurane anesthesia (time=–1 h). Animals in group 1A receive no injection. After 1 h (time=0) the animals in groups 1A, 1B, 1C, and 1D receive oral doses of naproxen in saline of 0, 0, 7.5 and 30 μmol/kg, respectively. The doses and time points of measurements are selected on the basis of simulations predicting measuring a full concentration-effect relationship within the time-span of the experiment[3].Mice[2]Bleomycin (0.05 IU) is instilled intratracheally to C57BL/6 mice, which are then treated by micro-osmotic pump with vehicle, JNJ7777120 (40 mg/kg b.wt.), naproxen (21 mg/kg b.wt.), or a combination of both. Airway resistance to inflation, an index of lung stiffness, is assessed, and lung specimens are processed for inflammation, oxidative stress, and fibrosis markers[2].

(S)-Naproxen is a non-selective COX inhibitor [1,2].

Cyclooxygenase (COX) is the key enzyme required for the conversion of arachidonic acid to prostaglandins. Cyclooxygenase enzymes have been involved in diverse physiological situations and disease processes ranging from inflammation to cancer. Until now, two cyclooxygenase isoforms have been identified, COX-1 and COX-2. The COX-1 enzyme is produced constitutively (i.e., gastric mucosa) and COX-2 is inducible (i.e., sites of inflammation) [3].

(S)-Naproxen inhibited the activity of human recombinant COX-1 and -2 with the IC50 values of 0.6-4.8 μM and 2.0-28.4 μM, respectively [1]. (S)-naproxen bound tightly to Aβfibrils with the Ki value of 5.70 ± 1.31 nM against [18F]FDDNP [2]. Pretreatment with (S)-naproxen significantly reduced the specific binding of [18F]FDDNP to regions of gray matter with SPs in AD specimens [4].

References:
[1] Barnett J, Chow J, Ives D, et al.  Purification, characterization and selective inhibition of human prostaglandin G/H synthase 1 and 2 expressed in the baculovirus system[J]. Biochimica et Biophysica Acta (BBA)-Protein Structure and Molecular Enzymology, 1994, 1209(1): 130-139.
[2] Laneuville O, Breuer D K, Dewitt D L, et al.  Differential inhibition of human prostaglandin endoperoxide H synthases-1 and-2 by nonsteroidal anti-inflammatory drugs[J]. Journal of Pharmacology and Experimental Therapeutics, 1994, 271(2): 927-934.
[3] Dubois R N, Abramson S B, Crofford L, et al.  Cyclooxygenase in biology and disease[J]. The FASEB journal, 1998, 12(12): 1063-1073.
[4] Agdeppa E D, Kepe V, Petri A, et al.  In vitro detection of (S)-naproxen and ibuprofen binding to plaques in the Alzheimer’s brain using the positron emission tomography molecular imaging probe 2-(1-{6-[(2-[18 F] fluoroethyl)(methyl) amino]-2-naphthyl} ethylidene) malononitrile[J]. Neuroscience, 2003, 117(3): 723-730.