Outstanding Anti-inflammatory Potential of Selected Asteraceae Species through the Potent Dual Inhibition of Cyclooxygenase-1 and 5-Lipoxygenase.

Cyclooxygenase and 5-lipoxygenase are enzymes that catalyze important inflammatory pathways, suggesting that dual cyclooxygenase/lipoxygenase inhibitors should be more efficacious as anti-inflammatory medicines with lower side effects than the currently available nonsteroidal anti-inflammatory drugs. Many plants from the family Asteraceae have anti-inflammatory activities, which could be exerted by inhibiting the cyclooxygenase-1 and 5-lipoxygenase enzymes. Nevertheless, only a small number of compounds from this family have been directly evaluated for their ability to inhibit the enzymes in cell-free assays. Therefore, this study systematically evaluated 57 Asteraceae extracts in vitro in enzyme activity experiments to determine whether any of these extracts exhibit dual inhibition of cyclooxygenase-1 and 5-lipoxygenase. The chemical profiles of the extracts were obtained by the high-performance liquid chromatography-ultraviolet-diode array detector method, and their major constituents were dereplicated. Of the 57 tested extracts, 13 (26.6 %, IC50 range from 0.03-36.2 µg/mL) of them displayed dual inhibition. Extracts from known anti-inflammatory herbs, food plants, and previously uninvestigated species are among the most active. Additionally, the extract action was found to be specific with IC50 values close to or below those of the standard inhibitors. Thus, the active extracts and active substances of these species are potent inhibitors acting through the mechanism of dual inhibition of cyclooxygenase-1 and 5-lipoxygenase. The extracts were prepared for this study using nontoxic extraction solvents (EtOH-H2O), requiring only a small amount of plant material to carry out the bioassays and the phytochemical analyses. In summary, this study demonstrated the potential of the investigated species as dual inhibitors, revealing their potential as pharmaceuticals or nutraceuticals.