Aqueous extract of Plinia edulis leaves: Antioxidant activity and cytotoxicity to human breast cancer MCF-7 cell line

Abstract

The aqueous extract of Plinia edulis leaves (AEP) was evaluated for its in vitro antioxidant potential and cytotoxicity to MCF-7 cells, a human breast adenocarcinoma cell-line that express the estrogen receptor α (ER+). AEP exhibited total antioxidant capacity (324.20±3.14mg/g) and strong scavenging activity on DPPH free radical, with maximum effect at 20μg/mL. AEP and cyclophosphamide (cytotoxic agent) treatment for 24 and 48h decreased the cell protein content, as compared to control cells. Morphological analysis, after hematoxylin–eosin staining of cells, showed changes such as cell rounding-up, shrinkage, nuclear condensation and reduction of colony and cell diameter (p<0.01), thereby indicating that AEP is cytotoxic to MCF-7 cells. AEP treatment also induced cell death, with a maximum effect at 5μg/mL, and its mechanism of action seems to include the induction of apoptosis, as a DNA ladder-pattern was obtained in the DNA analysis. Oxidative stress is supposed to play an important role in cancer initiation and progression. Considering that AEP showed to be antioxidant and cytotoxic, the extract seems to be a chemopreventive agent and a good candidate for antineoplastic drug development.