Efficacy and toxicity of Anatolian propolis on healthy nasal epithelial cells.

OBJECTIVE In our study we aimed to evaluate the effects of applying propolis topically to epithelial cells of the nasal cells, to discover whether this causes any toxic effect upon the cells. MATERIALS AND METHODS Samples of healthy human primary nasal epithelium harvested during septoplasty from volunteers were incubated in cell culture. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays may be utilized when assessing cellular damage (toxicity), as evidenced by DNA fragmentation, nuclear condensation, alteration in the outer plasma membrane and cytoskeletal alteration. This was the method used in the study. Cultured epithelial cells were incubated with propolis (Bee&You) for 24 hours at 37°C. The MTT assay was then performed, and the cell morphology was examined by confocal microscopy. In addition, via wound healing assay, cellular proliferation was assessed by the artificial scratch method followed by light microscopy. RESULTS MTT assay results showed that the primary nasal cells were not affected by the topical application of propolis for 24 hours. All of the applied doses not changed significantly the viability of the cells. The agent was not found to be cytotoxic to the primary nasal cells in the application time of 24 hours. Our confocal microscopy findings supported the MTT findings. According to the confocal images, control cells that were not treated with test agent were with compact morphology and undamaged fusiform cell shape and nucleus. In test group of nasal cells, Propolis was found not to be cytotoxic on the cellular morphology and not changed the cells. When evaluating the results from the wound healing assay, the clear area of scratch obtained at the start of incubation (0th) was closed totally with the proliferated primary nasal cells after incubation of 24 hours with propolis. These findings are supported by our MTT findings that imply to the slight induce of proliferation of the primary cells by Propolis. CONCLUSIONS Topically applied propolis did not have a cytotoxic effect on nasal epithelium cells. Considering its antibacterial and antioxidant effects, it has been concluded that topical application in sinonasal inflammatory diseases (e.g., acute and chronic rhinosinusitis) may have an auxiliary effect in treatment. Moreover, there is a slight induce of proliferation of the primary cells by propolis which may help wound healing in septal surgeries and epistaxis.