Animal experiment:

First, Ketoprofen (RP-19583) (0.1-1.0 mg/kg) and morphine (0.1-1.0 mg/kg) are evaluated for their effectiveness to block U69,593-induced depression of nesting. For these studies, Ketoprofen (RP-19583) or morphine is administered 30 min before nesting, 1.0 mg/kg U69,593 is administered 15 min before nesting, and each set of conditions is tested in a group of six mice[2].

Ketoprofen (RP-19583) is a non-steroidal antiinflammatory agent, acting as a potent inhibitor of COX, with IC50s of 2 nM and 26 nM for COX-1 and COX-2 in human blood monocytes, respectively.

Ketoprofen (Compound 2) is a non-steroidal antiinflammatory agent, acting as a potent inhibitor of COX, with IC50s of 2 nM and 26 nM for COX-1 and COX-2 in human blood monocytes, respectively[1].

Ketoprofen (RP-19583) (0.32-10 mg/kg, s.c) dose-dependently inhibits acid-induced depression of nesting (IC50, 2.05 mg/kg), and reverses CFA-induced such depression at 0.1-10 mg/kg, with an IC50 of 0.18 mg/kg in mice[2].

References:
[1]. Palomer A, et al. Structure-based design of cyclooxygenase-2 selectivity into ketoprofen. Bioorg Med Chem Lett. 2002 Feb 25;12(4):533-7.
[2]. Negus SS, et al. Effects of ketoprofen, morphine, and kappa opioids on pain-related depression of nesting in mice. Pain. 2015 Jun;156(6):1153-60.