Metabolomic approach and in silico methods for the discovery of dual inhibitors of COX and LOX from Aldama species (Asteraceae)

Abstract

The genus Viguiera Kunth is the largest taxa of subtribe Helianthinae (tribe Heliantheae, Asteraceae) and recently its South American species were transferred to the genus Aldama La Llave [1]. Previous studies have shown that Aldama species have anti-inflammatory potential due to the presence of sesquiterpene lactones [2] as well as phenolic compounds. Thus, this study aimed to investigate the in vitro anti-inflammatory potential of Aldama species through inhibition of the enzymes cyclooxygenase (COX) and lipoxygenase (LOX) concomitantly as well as to identify their bioactive compounds using a metabolomic approach and in silico methods. Seventy nine species from different genera of Asteraceae were collected in the Brazilian vegetations “Mata Atlântica”, “Pampa” and, principally, in the “Cerrado”, and among them 21 comprised Aldama species. Dried and powdered leaves of each species were macerated in EtOH-H2O 7:3 (v/v, 2 mL; 25 oC) in an orbital shaker for 24h to yield their respective crude extracts. One aliquot of each extract was analyzed by UHPLC-UV-HRFTMS (Thermo Fisher Scientific, USA), and another one was tested in vitro using COX-1 and 5-LOX inhibitor screening assay kits (Cayman Chemical®, USA). From the 79 species, 14 showed dual inhibition. LC-MS data in the negative mode were normalized using the software MZmine 2.10 (MZmine Development Team, USA) and evaluated in SIMCA-P 13.0.2.0© (Umetrics, Sweden). A prediction model using O2PLS-DA was built using nine active species (R2 = 0.99, Q2 = 0.67 and accuracy = 68.75%) and it was found that three so far uninvestigated Aldama species have potencial to inhibit both enzymes. The active compounds were dereplicated using commercial and in house natural products databases and are currently being isolated to further confirm their biological activities.