Water and ethanol extracts of Plantago major leaves show anti-inflammatory activity on oral epithelial cells

CONTEXT: The leaves of Plantago major have been used for the treatment of wounds and inflammation in folk medicine from prehistoric times. However there is no report on the use of P. major to treat inflammation in oral epithelial cell lines. OBJECTIVE: The present study was undertaken to reveal possible anti-inflammatory effects of Plantago major leaf extracts on oral epithelial cells in-vitro. MATERIALS AND METHODS: Water- and ethanol-based extracts of P. major leaves were prepared from freeze-dried plant material, and tested in-vitro using the oral epithelial cell line H400. The anti-inflammatory activity of P. major was tested against E. coli lipopolysaccharide (LPS) using the nuclear factor kappa beta (NF-kB) assay. RESULTS: Both the water- and the ethanol-based extracts, as well as a combination of the two extracts, showed anti-inflammatory activity. A concentration of 0.1 mg/mL (on dry weight basis) yielded the best results for all extracts. DISCUSSION AND CONCLUSION: The results show that synergistic effects of both polyphenols and water-soluble compounds (possibly polysaccharides) are responsible for anti-inflammatory activities of P. major.