Screening of 35 plants used in Austrian folk medicine for PPAR-α and -γ activation and NFkB inhibition

Austria and its adjacent regions have a great history in traditional folk medicine. Folk-medicinal knowledge was collected over years and transferred to the VOLKSMED database [1] which contains an exact botanical description of each used plant. The aim of this study was to investigate the potential in vitro anti-inflammatory activity of plants selected from that database, using luciferase reporter gene assays.

Thirty five preselected plants were extracted with dichloromethane (DCM) and methanol (MeOH) using the Accelerated Solvent Extractor (Dionex ASE200). The chlorophyll, if present, was separated from the DCM extract, whereas the tannins were removed from the MeOH extract, in order to avoid possible interferences with the assay formats [2]. Crude and purified extracts were then examined for activation of PPAR-α and -γ and inhibition of NFκB using HEK293 cells transfected with green fluorescence protein plasmid (as internal control). The cells were also accordingly transfected with PPAR-α or -γ plasmids and reporter plasmid pPPRE-tk3x-Luc in the PPAR assay, while a pNFκB-luc transfection and a TNF-α stimulation were used in the NF-kB assay. Luciferase activity and fluorescence intensity were then measured using a GeniosPro plate reader.

The extracts of fifteen plants showed no activity in the applied assays, while the other twenty exhibited activity in one or more of the test systems. The three most active ones in both assays were the DCM extract with the chlorophyll separated of Urtica dioica leaves, the MeOH extract with the tannin separated of Sambucus nigra fruits and the DCM extract with the chlorophyll separated of Prunella vulgaris herb.

Acknowledgements: This work is funded by the Austrian Science Fund FWF: S10704-B037

References: [1] Saukel, J. (2006) Sci. Pharm. 74:36.

[2] Potterat, O. and Hamburger, M. (2006) Curr. Org. Chem. 10:899–920