Synergistic anti-inflammatory activities of a new flavone and other flavonoids from Tephrosia hildebrandtii vatke

Abstract

A new flavone, named hildeflavone (1) along with 7 other known flavonoids were isolated from the aerial parts of Tephrosia hildebrandtii Vatke. Their characterisation was based on NMR and MS data analysis. The anti-inflammatory properties of the crude extract, isolated compounds and combination of the compounds were investigated in lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cells (PBMCs). Treatment of the LPS-stimulated PBMCs with the isolated flavonoids at a concentration of 100 µM significantly reduced the production of interleukins (IL-1β, IL-2 and IL-6), interferon-gamma (IFN-γ), granulocyte macrophage-colony stimulating factor (GM-CSF) and tumour necrosis factor-alpha (TNF-α). It was also found that the combination of a flavone and flavanones exhibited remarkable synergistic anti-inflammatory effects on the production of the cytokines.

Keywords:

• Fabaceae
• Tephrosia hildebrandtii
• flavonoid
• anti-inflammatory
• hildeflavone
• cytokine
• synergy

Acknowledgments

ROO is grateful to the German Academic Exchange Services (DAAD) for a doctoral scholarship which was offered through the Natural Products Research Network for Eastern and Central Africa (NAPRECA) which also supported his research stay in TU Dortmund. Mr. Patrick Mutiso (The Herbarium, School of Biological Sciences, University of Nairobi) is acknowledged for authentication of the plant. We are thankful to Dr. Wolf Hiller (Faculty of Chemistry and Chemical Biology, TU Dortmund) for the realization of the NMR measurements, Mr. Michael Kubicki for the acquisitions of HRESIMS and Mrs. G. Hardes (INFU, TU Dortmund) for technical assistance.

Disclosure statement

No potential conflict of interest was reported by the authors