Does etodolac affect TRPA1 functionality in human?

OBJECTIVES

In preclinical research, etodolac, a non-steroidal anti-inflammatory drug, affected transient receptor potential ankyrin 1 (TRPA1) activation. Yet, whether the interaction between etodolac and TRPA1 translates to altered TRPA1 functionality in human remains to be investigated.

METHODS

A randomized, double-blinded, celecoxib-controlled study was conducted to assess the effect of etodolac on TRPA1-mediated dermal blood flow (DBF) changes on the forearm of 15 healthy, male volunteers aged between 18 and 45 years. Over four study visits, separated by at least five days wash-out, a single or four-fold dose of etodolac 200 mg or celecoxib 200 mg was administered orally. Two hours post-dose, TRPA1 functionality was evaluated by assessing cinnamaldehyde-induced DBF changes. DBF changes were quantified and expressed in Perfusion Units (PUs) using laser Doppler imaging during 60 min post-cinnamaldehyde application. The corresponding area under the curve (AUC) was calculated as summary measure. Statistical analysis was performed using Linear mixed models with post-hoc Dunnett.

RESULTS

Neither the single dose of etodolac nor celecoxib inhibited the cinnamaldehyde-induced DBF changes compared to no treatment (AUC ± SEM of 17,751 ± 1,514 PUsmin and 17,532 ± 1,706 PUsmin vs. 19,274 ± 1,031 PUsmin, respectively, both p=1.00). Similarly, also a four-fold dose of both compounds failed to inhibit the cinnamaldehyde-induced DBF changes (19,235 ± 1,260 PUsmin and 19,367 ± 1,085 PUsmin vs. 19,274 ± 1,031 PUsmin, respectively, both p=1.00).

CONCLUSIONS

Etodolac did not affect the cinnamaldehyde-induced DBF changes, suggesting that it does not alter TRPA1 functionality in human.