Evidence suggests that most chemotherapeutic agents are less effective as treatment in patients with estrogen receptor-negative (ER-) breast carcinomas compared to those with estrogen receptor-positive (ER+) breast carcinomas. Moreover, African American Women (AAW) is disproportionately diagnosed with ER- breast cancer compared to their white counterparts. Novel therapies effective against ER- breast carcinomas are urgently needed to ameliorate the health disparity. Previous reports show that low concentrations (microgram/ml) of water-soluble leaf extracts of a Nigerian edible plant, V. amygdalina (VA), potently retards the proliferative activities of ER+ human breast cancerous cells (MCF-7) in vitro in a concentration-dependent fashion. However, the anti-proliferative activities of VA in either ductal or ER- carcinoma cells have not been characterized. The exposure of BT-549 to increasing concentrations of VA (10, 100, and 1000 microg/mL) inhibited cell growth by approximately 14 % (P<0.05), 22 % (p<0.05), and 50 % (p<0.005) respectively. The cell count studies were corroborated by DNA synthesis studies. Treatments of BT-549 with 10, 100, and 1000 microg/mL VA inhibited DNA synthesis in a concentration dependent fashion by 22 %, 76 % (P<0.05), and 86 % (p<0.01) respectively. BT-549 cells were insensitive to 10 and 100 nM paclitaxel (TAX) treatments. Isolation of DNA from dried VA leaves yielded approximately 12.2 and 1 kbp genomic DNA that were Eco RI-insensitive but Hind III and Bam HI-sensitive. These pieces of information may be used to enhance the safety of medicinal botanical VA through authentication, and adulteration detection.