Hydroalcoholic plant extracts with anti-inflammatory activity.

The aim of the present study was to investigate if standardized hydroalcoholic plant extracts such as Calendula officinalis, Hypericum perforatum, Plantago lanceolata and Glycyrrhiza glabra can suppress in cell-free systems the activities of 5-lipoxygenase (5-LO) and cyclooxygenase-2 (COX-2), key enzymes in the formation of proinflammatory eicosanoids from arachidonic acid (AA). Studies were undertaken to compare the above mentioned plant extracts to a known NSAID (nimesulide) in their ability to inhibit both cyclooxygenase (COX-2) and lipoxygenase (5-LO) activities in cell-free systems. We report on 2 vegetal extracts (Hypericum perforatum and Glycyrrhiza glabra) that inhibit 5-LO activity and 2 vegetal extracts (Plantago lanceolata and Glycyrrhiza glabra) that inhibit COX-2 activity.