Multiple effects of Alchemilla vulgaris L. extract on melanoma cells and tumor microenvironment

Abstract

Several ethnobotanical reports on Alchemilla vulgaris L. pointed out diverse biological properties against problems such as dysmenorrhea, pruritus vulvae, menopausal complaints as well as related diseases in women. Also previous studies have shown that Alchemilla vulgaris L. extracts are exhibiting antiinflammatory, antioxidant, wound healing and neuroprotective activity. The aim of this study was to evaluate the direct effect of Alchemilla vulgaris L. ethanol extract against melanoma cells in vitro and in vivo, as well as its effect on tumor microenvironment ex vivo. This study was performed on two different mouse melanoma cell lines, B16 and B16F10, and on syngeneic mouse melanoma model in vivo. Obtained results revealed dose‐dependent decrease of cell viability after 72 h‐ treatment with Alchemilla vulgaris L. extract. The observed effect was followed by loss of dividing potential in both tested cell lines. In parallel with this, certain percentage of B16F10 cells was subjected to programmed cell death in a caspase independent manner while in B16 cells estimation of the presence of autophagosomes by flow cytometry has shown that autophagy is occurring after the treatment and it is shown to be mechanism of death. Concerning in vivo studies Alchemilla vulgaris L. extract significantly reduced tumor growth in B16 melanoma model partly through stimulation of antitumor immune responce. It altered dendritic cells phenotype which activated cytotoxic and CD4+ T lymphocytes to successfully destroy tumor cells. In summary, these data indicate that Alchemilla vulgaris L. is valuable of further investigation in the field of experimental oncology.