Pharmacological evaluation of 1-(carboxymethyl)-3,5-diphenyl-2-methylbenzene, a novel arylacetic acid with potential anti-inflammatory properties

Abstract.

Objective and Design: 1-(Carboxymethyl)-3,5-diphenyl-2-methylbenzene (CDB), a novel arylacetic acid, was evaluated in vivo for its ability to inhibit acute and chronic inflammation as well as acute pain.¶Materials and Methods: The effects of CDB were evaluated using the following assays: 1) acute inflammation induced by the injection of carrageenan, bradykinin and serotonin into the subplantar region of the hind paw of rats; 2) chronic inflammation produced by the injection of Mycobacterium butyricum into the base of the tail of rats; 3) acute pain induced by the i.p. injection of phenyl-p-quinone into mice resulting in the production of writhes; 4) cyclooxygenase (COX) activity, including COX-1 and COX-2, evaluated using whole blood; and 5) activity of peptidylglycine α-monooxygenase (PAM) isolated from Xenopus laevis skin.¶Results: CDB (10 to 100 mg/kg s.c.) produced a dose-dependent inhibition of carrageenan edema (ED₅₀ of 41 mg/kg at 3 h) which continued for up to 12 h. Using a therapeutic dosing regimen, this compound inhibited hind paw inflammation (>70%) and arthogram scores in rats with adjuvant-induced arthritis. This compound also possessed significant analgesic activity in mice (70% inhibition with 50 mg/kg). CDB, however, lacked inhibitory activity on bradykinin and serotonin-induced edema. In addition, CDB significantly inhibited COX-1 activity (IC₅₀ ≅ 17 μM) while having only a weak inhibitory activity on both COX-2 and PAM activity.¶Conclusions: CDB is an effective anti-inflammatory/analgesic agent whose mechanism of action appears to be associated with inhibition of COX-1 activity.