ABSTRACT
This review summarises recent developments in the search for natural products with
effect on the isoenzyme cyclooxygenase-2 (COX-2). Two strategies are described, whose
objective is to find substances of natural origin, which either affect the in vitro
prostaglandin biosynthesis which is catalysed by COX-2, or which affect the expression
of COX-2. The effect on COX-2 of a number of plant extracts and of 65 isolated com-
pounds with origins in terrestrial plants, microorganisms and marine organisms, are
summarised and discussed. Examples are also given of how inhibitors of cyclooxygenase
catalysed biosynthesis in vitro can be isolated using bioassay guidance. The COX-2 regu-
lators which are identified, are of many different origins and represent a molecular
diversity which includes stilbenes, antrhaquinones, flavonoids, alkaloids, fatty acids and
terpenoids. All of these have different selective activities on COX-2. The search for regu-
lators of COX-2 from natural sources can reveal novel structure-activity relationships
which can be used in the drug discovery process, such as the development of improved
anti-inflammatory drugs and use as pharmacological probes in inflammatory research.
