In vitro Antiproliferative Effects of Cotinus coggygria Scop. on human non-melanoma and melanoma skin cancer cells

Skin cancer is one of the most frequently diagnosed malignancies worldwide and its incidence constantly increases. The disease divides in two major subtypes: non-melanoma and melanoma skin cancer. The main drawbacks of the traditional skin cancer therapy are primary and acquired drug resistance and serious side effects due to the nonspecific treatments targeting. Despite advances in therapy strategies there is a need of new affordable natural anti-skin cancer agents, which to possess higher efficiency without causing detrimental side effects. Medicinal plants provide great possibility for the discovery of new anticancer therapeutics with preventive and treatment potential. Cotinus coggygria Scop. is a plant species widely applied in phytotherapy predominantly against disorders of the skin and mucosal tissues. The herb has a large range of valuable biological activities but its anticancer properties have not been thoroughly studied. The aim of the present research was to assess the antiproliferative properties of the crude leaf aqueous ethanolic extract from Bulgarian herb C. coggygria and its chloroformic and aqueous fractions on a panel of human skin cancer cell lines: basal cell carcinoma (TE 354.T), squamous cell carcinoma (A431) and malignant melanoma (A375) and to compare them to the cell growth inhibitory potential on normal dermal cell line (BJ). The antiproliferative capacity of the plant substances was investigated using MTT assay and microscopy cell morphology observation after 72 h cell treatment in a wide scale of concentrations. The obtained results showed that the crude extract and both fractions inhibit significant proliferation of A431 squamous cell carcinoma and A375 melanoma cells with the highest cytostatic effect registered for the aqueous fraction on A375 cells with a half maximal inhibitory concentration value of 44.33 ?g/ml. C. coggygria exhibited no cytostatic activity towards TE 354.T basal cell carcinoma cells. The established marked slighter reduction in the growth of normal BJ cell line in comparison to cancer A375 and A431 cells was indicative for a selectivity in the antiproliferative action. It could be concluded that medicinal plant C. coggygria possesses promising antiproliferative properties against A375 and A431 skin cancer cell lines which will be further investigated in details.