Discovery of COX-1 and 5-LOX dual inhibitors by UHPLC-HRFTMS-metabolomics

Recently, a methodology for the evaluation of Asteraceae extracts in vitro in the cyclooxygenase-1 (COX-1) and 5-lipoxygenase (5-LOX) enzymes has been developed [1]. In that study, 57 extracts were evaluated and 13 of them displayed dual inhibition of COX-1 and 5-LOX [1]. Based on the results in vitro, a combined strategy using UHPLC-HRFTMS-metabolomics and in silico methods has been used to detect dual inhibitors in the bioactive extracts [2,3]. Although this strategy allowed dereplication, no compound has been isolated and tested directly on the enzymes to confirm its activity. In this work, we used a similar strategy to target bioactive compounds from the leaf extracts of 24 uninvestigated Brazilian species of the genus Aldama as well as to confirm the in vitro effects of the compounds. In vitro enzyme inhibition tests [1] were carried out with the extracts and three of them displayed dual inhibition. The chemical profiles of the 24 extracts were obtained by UHPLC-HRFTMS [2,3] and an OPLS-DA model (R ²= 0.98 and Q ²= 0.51) was developed with the aim of detecting the compounds responsible for the dual activity. Four compounds were correlated with the bioactivity and extract dereplication using the Dictionary of Natural Products and our in-house data base AsterDB (www.asterbiochem.org/asterdb) led to the identification of four known phenolic compounds in the extract of A. robusta, two flavonoids and two trans-cinnamic acid derivatives. The four compounds were further obtained and evaluated directly on the enzymes. As a result, three compounds (3-O-E-caffeoylquinic acid, rutin and 3-O- methylquercetin) were found to be able to inhibit both enzymes and one 5-LOX only. In conclusion, the present study allowed the detection of COX-1 and 5-LOX dual inhibitors and their activities were further confirmed in experiments on the enzymes, therefore showing the usefulness of our strategy.

Acknowledgements: FAPESP (grant # 10/51454 – 3).

Keywords: Asteraceae, COX-1 and 5-LOX dual inhibitors, metabolomics, OPLS-DA, UHPLC-HRFTMS.

References:

[1] Chagas-Paula DA, Oliveira TB, Faleiro DPV, Oliveira RB, Da Costa FB. Outstanding anti-inflammatory potential of selected Asteraceae species through the potent dual inhibition of cyclooxygenase-1 and 5-lipoxygenase. Planta Med 2015; 81: 1296 – 1307

[2] Chagas-Paula DA, Oliveira TB, Zhang T, Edrada-Ebel R, Da Costa FB. Prediction of anti-inflammatory plants and discovery of their biomarkers by machine learning algorithms and metabolomic studies. Planta Med 2015; 81: 450 – 458

[3] Chagas-Paula DA, Zhang T, Da Costa FB, Edrada-Ebel R. A metabolomic approach to target compounds from the Asteraceae family for dual COX and LOX inhibition. Metabolites 2015; 5: 404 – 430