Asparagus officinalis L. aqueous extracts mediate cell cycle block and migration inhibition in breast cancer cells

Breast cancer (BC) is the most common cancer among women that shows high rate of resistance and loss of treatment response. Asparagus Officinalis (Asp) is cultivated both for food industry and medical use. In this study, we characterized the chemical content of new aqueous extracts derived from the non-edible portion of the plant that represents a food industry waste product. Biocompatibility and bioactivity of extracts were assayed in vitro on normal fibroblasts and on cellular models of BC (estrogen receptor-positive MCF-7 and triple-negative MDA-MB231). Results showed no interference with fibroblast viability, while a significant G1/S cell cycle arrest and low levels of apoptosis, were specifically observed in breast cancer cells. Asp extracts were also shown to significantly reduce cell migration after 24 hours of treatment in BC cells, in a dose-dependent manner. Additional investigation showed that Asp extracts exert specific pro-oxidant activity against tumoral cells and, notably, their combination with menadione resulted in a significant increase of oxidants production compared with menadione alone only in breast cancer cells (but not in normal cells). Moreover, based on U-SENSTM test performed on lymphoma cell line U937, used to evaluate the alteration of CD86, a cell surface marker involved in the activation of immune cells as monocytes and dendritic cells, the extracts can be classified as non-sensitizer, confirming their safety profile. Our results make the aqueous Asp extracts good candidates for deeper analysis in breast cancer research. The selectivity of action on tumoral cells and the relatively easy preparation make them attractive to test their role as co-adjuvant agents of clinical drug therapies.