Antimicrobial Activity, In Vitro Anticancer Effect (MCF7 Breast Cancer Cell Line), Antiangiogenic and Immunomodulatory Potentials of Populus Nigra L. Buds Extract

Purpose: The aim of this study was to evaluate the antioxidant potential, antimicrobial activity, the in vitro anticancer effect (MCF7 breast cancer cell line), as well as the antiangiogenic and immunomodulatory potential of Populus nigra L. bud (Pg) extract collected from the western part of Romania. Results: : Populus nigra L. bud extract presents an important antioxidant activity, due to the rich phytochemical composition. Regarding the biological activity, results have shown that poplar bud extract presents a significant inhibitory activity against Gram-positive bacteria and a dose-dependent decrease of MCF7 tumor cell viability with an IC 50 of 66.26 µg/mL, while not affecting healthy cells. Phenomena of early apoptotic events at the maximum concentration tested (150 µg/mL) were detected by Annexin V-PI double staining. The extract induced G0/G1 phase cell cycle arrest. In addition, Pg extract showed antiangiogenic potential on the chorioallantoic membrane. Also, at the highest concentration (150 µg/mL), good tolerability and no signs of toxicity upon vascular plexus were observed. Moreover, in low concentrations, the Pg extract had immunomodulatory activity on primary human dendritic cells by upregulating IL-12 and IL-23 subunits. Conclusion: The study concludes that poplar bud extract elicited antioxidant activity, antitumor properties on the breast cancer cell line, followed by an antiangiogenic effect and an immunomodulatory potential on human primary dendritic cells. The biological activity of Populus nigra L. buds extract may open new directions of research on the topic addressed.