In vivo anti‐inflammatory activity of Fabaceae species extracts screened by a new ex vivo assay using human whole blood

• Published in: Phytochemical analysis Vol. 32; no. 5; pp. 859 - 883
• Main Authors: Rosa, Welton, Silva Domingos, Olívia, Oliveira Salem, Paula Pio, Caldas, Ivo Santana, Murgu, Michael, Lago, João Henrique Ghilardi, Sartorelli, Patricia, Dias, Danielle Ferreira, Chagas‐Paula, Daniela Aparecida, Soares, Marisi Gomes
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01-09-2021
• Subjects: Assaying; Bioassays; Blood; Chromatography; dereplication; Drug development; ear edema; Ethics; Fabaceae; Inflammation; LC–MS/MS; Lipopolysaccharides; Liquid chromatography; LPS; Mass spectrometry; Mass spectroscopy; PGE2; plants; plasma samples; Prostaglandin E2; Quadrupoles; Scientific imaging; Screening; SPE; Species; Spectroscopy; UPLC‐ESI‐QTOF‐MS2; LC-MS/MS; PGE2; ear edema; plasma samples; plants; SPE; UPLC-ESI-QTOF-MS2; dereplication; LPS
• ISSN: 0958-0344; 1099-1565
• DOI: 10.1002/pca.3031

Introduction
Plants have been considered a promising source for discovering new compounds with pharmacological activities. The Fabaceae family comprises a large variety of species that produce substances with diverse therapeutic potential, including anti‐inflammatory activity. The limitations of current anti‐inflammatories generate the need to research new anti‐inflammatory structures with higher efficacy as well as develop methods for screening multiple samples, reliably and ethically, to assess such therapeutic properties.
Objective
Validate and apply a quantification method for prostaglandin E2 (PGE2) production from an ex vivo assay in human blood in order to screen anti‐inflammatory activity present in many Fabaceae species extracts.
Methods
Human blood was incubated with extracts from 47 Fabaceae species. After lipopolysaccharide (LPS)‐induced inflammation, PGE2 was quantified in the plasma by liquid chromatography with tandem mass spectrometry (LC–MS/MS). The extracts that presented PGE2 production inhibition were further assessed through in vivo assay and then chemically characterised through an analysis of ultra‐performance liquid chromatography electrospray ionisation quadrupole time‐of‐flight tandem mass spectrometry (UPLC‐ESI‐QTOF‐MS2) data.
Results
The new ex vivo anti‐inflammatory assay showed that five out of the 47 Fabaceae species inhibited PGE2 production. Results from an in vivo assay and the metabolic profile of the active extracts supported the anti‐inflammatory potential of four species.
Conclusion
The quantification method for PGE2 demonstrated fast, sensitive, precise, and accurate results. The new ex vivo anti‐inflammatory assay comprised a great, reliable, and ethical approach for the screening of a large number of samples before an in vivo bioassay. Additionally, the four active extracts in both ex vivo and in vivo assays may be useful for the development of more efficient anti‐inflammatory drugs.
We developed a new ex vivo assay in human blood to screen anti‐inflammatory activity present in Fabaceae species extracts. Five out of forty‐seven Fabaceae species assessed inhibited PGE2 production in LPS‐induced blood. In vivo anti‐inflammatory assay for ear edema inhibition assessment confirmed the pharmacological potential of four out of five active species in the new ex vivo assay. Dereplication of the five active extracts in ex vivo assay supported the anti‐inflammatory potential of those active species assessed.