J Pharm Pharmaceut Sci (www.cspscanada.org) - 2006
Our paper (1) contained the following passage which was taken with some modification from a comment by David Aronoff published in a website (2). The reference to the Aronoff's statement was, however, inadvertently omitted from our paper. We acknowledge this oversight.
"A significant limitation of this study is that the basal PGHS activities (as measured by PGE2 production from exogenous arachidonic acid) of the three Sf9 constructs were significantly different. For example, the COX-3 construct was approximately 20% as active as the COX-1 construct and was only ca. 4% as active as the COX-2 construct. Therefore, it is difficult to know whether ApAP truly has a greater ability to inhibit COX-3>COX-1>>COX-2, or if the IC50's merely reflect the variable activities of the Sf9 constructs. The authors could have improved this assay by using Sf9 constructs with equivalent arachidonic acid utilization. Employing purified (or microsomal) preparations of the three COX isoforms exhibiting similar specific activities would also allow a better comparison of the inhibitory potency of ApAP against the isoforms."
NM Davies, RLGood, KA Roupe, JA Yanez
College of Pharmacy Washington State University
Pullman, WA, USA, 99164-6534