Zinc and propolis reduces cytotoxicity and proliferation in skin fibroblast cell culture: total polyphenol content and antioxidant capacity of propolis.

It has been demonstrated that zinc exerts its beneficial influence on skin fibroblasts. Propolis, a complex mixture of plant-derived and bees' products, was reported to stimulate cicatrization processes in skin and prevent infections. The aim of this study was to find out how zinc and propolis influence human skin fibroblasts in cell culture and to compare the effect of individual compounds to the effect of a mixture of zinc and propolis. In this study, zinc, as zinc aspartate, at a concentration of 16 μM, increased human fibroblasts proliferation in cell culture, whereas propolis at a concentration of 0.01% (w/v) revealed antiproliferative and cytotoxic action followed by mild cell necrosis. In culture, zinc was effectively transported into fibroblasts, and propolis inhibited the amount of zinc incorporated into the cells. An addition of propolis to the medium caused a decrease in the Zn(II) amount incorporated into fibroblasts. The obtained results also indicate an appreciable antioxidant property of propolis and revealed its potential as a supplement when applied at doses lower than 0.01% (w/v). In conclusion, the present study showed that zinc had a protective effect on human cultured fibroblasts' viability, although propolis revealed its antiproliferative action and caused mild necrosis.