Effects of Plantago major L. leaf extracts on oral epithelial cells in a scratch assay

Ethnopharmacological relevanceThe present study was undertaken to evaluate the effects from different leaf extracts of the traditional medicinal herb Plantago major L. (plantain) on cell proliferation and migration in vitro, as a test for potential wound healing properties.Materials and methodsWater and ethanol-based extracts were prepared from Plantago major fresh and dried leaves, and tested in vitro in a scratch assay with oral epithelial cells.ResultsThe scratch assay produced reliable results after 18 h. Most of the tested extracts increased the proliferation/migration of the oral epithelial cells compared to the negative control. A concentration of 1.0 mg/mL (on dry weight basis) appears to be optimal regardless of type of extract, and among the alternatives, 0.1 mg/mL was always better than 10 mg/mL. Ethanol-based extracts with a concentration of 10 mg/mL had very detrimental effects on cell proliferation/migration. At the other two concentrations, ethanol-based extracts had the most beneficial effect, followed by water extracts of fresh leaves, ethanol plus water extracts of dried leaves and, finally, water extracts of dried leaves.ConclusionsThis study suggests that both the water extracts and the more polyphenol-rich ethanol-based extracts of Plantago major leaves have medicinal properties. Further research is, however, needed to determine what compounds are responsible for the wound healing effects.