Elaiophylin exerts antitumor effects in human breast cancer cells by inducing apoptosis and modulating MAPK signaling: Therapeutic implications.

Breast cancer (BC) is a leading contributor to cancer-associated deaths among women, underscoring the urgent need for novel therapeutic options. Elaiophylin, a macrocyclic lactone antibiotic, has attracted increasing interest because of its potential antitumor activity. We evaluated the effects of Elaiophylin in human BC cell lines (MCF-7 and MDA-MB-231) and in the non-tumorigenic mammary epithelial cell line MCF-10A. Elaiophylin inhibited breast cancer cell growth and induced G2/M-phase arrest. It also promoted apoptosis, accompanied by increased Bax expression and reduced Bcl-2 levels. Mechanistically, Elaiophylin decreased ERK phosphorylation while increasing p38 MAPK phosphorylation, consistent with modulation of MAPK signaling. Elaiophylin showed comparatively limited cytotoxicity in MCF-10A cells, suggesting preferential activity toward malignant cells. These findings provide mechanistic insight into the antitumor activity of Elaiophylin and support its further preclinical evaluation in breast cancer.