Planta Med 2011; 77 - PM106
DOI: 10.1055/s-0031-1282864

Mechanism of action of Fragaria vesca leaf extract on LPS treated macrophages

JT Liberal 1, V Francisco 1, MT Amaral 2, C Marques 3, MC Lopes 4, MT Cruz 4, MT Batista 5
  • 1Center for Pharmaceutical Studies, Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal; Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
  • 2Center for Pharmaceutical Studies, Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
  • 3Center of Ophthalmology and Vision Sciences, Institute of Biomedical Research in Light and Image, Faculty of Medicine, University of Coimbra, Coimbra, Portugal
  • 4Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal; Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
  • 5Center for Pharmaceutical Studies, Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal; Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal

Fragaria vesca L., commonly known as Strawberry, has been used over the years by traditional medicine for the treatment of several diseases. However, scientific reports of its molecular action mechanism are lacking.

Thus, this work aims to investigate the anti-inflammatory effects, of a Fragaria vesca leaves extract obtained by successive extractions with ethanol and 50% aqueous ethanol, on the macrophage cell line, Raw 264.7, stimulated with lipopolysaccharide (LPS). For this purpose nitric oxide (NO) production, scavenging activity and cytotoxicity of the extract were assessed. Furthermore, was evaluated the expression of proteins that are potential targets to prevent or treat chronic inflammation, namely iNOS, COX-2, phospho-IκB-α and IκB-α.

The results demonstrated that Fragaria vesca leaves extract was not cytotoxic and inhibit the production of NO triggered by LPS. Using (S)-Nitroso-N-acetylpenicillamine as NO donor, the extract promoted a significant decrease of NO in the culture medium. Western Blot analysis showed that LPS triggered a significant increase on iNOS and COX-2, though no significant differences were observed between cells treated with LPS or co-treated with the extract. Furthermore, in cells stimulated with LPS we observed a strong decrease on the content of IκB-α, while phosphorylated IκB-α strongly increased. However, an increase on the phosphorylation of IκB-α occurred in cells co-treated with the plant extract and LPS, suggesting a potential reduction of proteasome degradation, since phospho-IκB-α is a target for the ubiquitin-proteasome pathway.

In conclusion, our data show that Fragaria vesca decreased the level of nitrites, mainly through direct NO scavenging activity of the extract.

Keywords: Fragaria vesca, strawberry, anti-inflammatory properties, scavenger activity, proteasome inhibition

Acknowledgement: Research supported by FCT PhD fellowship SFRH/BD/72918/2010 and FCT project PTDC/SAU-FCF/105429/2008 and FEDER/COMPETE (FCOMP-01–0124-FEDER-011096).