Cytotoxic effects of different solvents and essential oil of eucalyptus on human fibroblast cells

There are reports that essential oils of different species of eucalyptus have special properties including anti-bacterial, antiviral, anticancer and insecticidal activities. Most of plant essential oils are dissolved in polar or non-polar solvents before examination. The aim of this study was to determine the cytotoxic effects of different solvents and essential oil of eucalyptus on human fibroblast cells. This experimental study was performed in the Institute of Biotechnology affiliated to Iranian Research Organization for Science and Technology during 2013-2014. The studied solvents were including ethanol, propylene glycol, dichloromethane, and dimethyl sulfoxide. Fibroblast cells were seeded in 96-well plates. After 24 h incubation at 37ºC, the cells were treated with different concentrations of the solvents or essential oil of eucalyptus (0.05-1 mg/ml). The viability of the cells was determined by the colorimetric MTT assay. Data were analyzed using T-test and One-way ANOVA. The lowest cytotoxic effect against fibroblast cells was related to 1% ethanol and propylene glycol, while the highest cytotoxic effect was related to 10% dimethyl sulfoxide that decreased cell survival by 47%. Essential oil of eucalyptus also induced fibroblast cell death at concentrations higher than 0.05 mg/ml. For clinical application of essential oil of eucalyptus, using solvent with appropriate concentration is necessary to prevent its cytotoxic effects.