Dictyota dichotoma (phaeophyceae) methanolic extracts exhibit antitumoral effects on breast cancer cells and induce osteoblasts differentiation

Abstract

There is a growing interest in macroalgae as natural products with antioxidant and anticancer activity. In this work, we studied the anti-tumoral effect of an algal extract (AE) derived from the marine alga Dictyota dichotoma on human breast cancer cells (MCF-7). We also evaluated the cytotoxic effects on non-tumorigenic cells and the effects on ostoblastogenesis in vitro. We found that the AE contains high levels of polyphenols and anti-oxidant activity measured by DPPH and Folin-Ciocalteu methods, respectively. Using trypan blue and MTS assays we demonstrated a significant inhibition of MCF-7 cell proliferation and viability. The changes in protein phosphorylation levels were examined through Western blot analysis, finding a decrease of phosphorylated AKT (Ser473) and its target molecule BAD (Ser136). In addition, AE inhibits cell migration determined through the wound healing assay and decreases cellular adhesion at all concentrations probed. Interestingly, AE does not affect the number and morphology of normal osteoblastic human cells, indicating its selectivity. Moreover, using colorimetric methods, we found that low doses of AE increase the production of osteoblastogenesis markers. These findings indicate that D. dichotoma is a valuable source of bioactive compounds for its regulatory effects on processes involved in metastasis and healthy effects in osteoblasts.