Investigating the anti-inflammatory effects of helenalin on wound healing

Arnica montana is used for its anti-inflammatory and tissue healing properties after trauma, bruises, or tissue injuries, but its cellular and molecular mechanisms are completely unknown yet. One of the main active compounds of A. montana is helenalin, a sesquiterpene lactone that can be found in various plants in Asteraceae. In this study, wound healing activity of helenalin in LPS-stimulated and non-stimulated medium conditions on HaCaT cells was evaluated. THP-1 cells were stimulated by LPS containing medium. Firstly, HaCaT and THP-1 cells were treated with different concentrations (between 50 to 0,095 µM) of helenalin for determining the toxic or non-toxic concentrations by using WST-1 method. Then the effects of non-cytotoxic concentrations (0,02, 0,2 and 2 µM) of helenalin on HaCaT cell proliferation and cell migration were determined using Real Time Cell Analysis System (xCELLigence). Scratch assay was performed in relation to wound closure. Cytokine levels of helenalin were measured at inflammatory and non-inflammatory conditions at 48h. As a result, high concentrations (higher than 1,56 µM) of helenalin showed significant cytotoxic effects on HaCaT and THP-1 cells. Therefore, wound healing activity at 0,02, 0,2 and 2 µM concentrations of helenalin were investigated. According to the results of real time cell proliferation, migration, scratch and cytokine analyses, HaCaT cells treated with 0,02 and 0,2 µM helenalin in LPS-stimulated medium have significantly increased cell proliferation, scratch closure and antiinflammatory effects. In particular, the highest wound healing activity on HaCaT cells was determined with 0.02 µM helenalin concentration in LPS-stimulated medium.