The acetone extract of Sclerocarya birrea (Anacardiaceae) possesses antiproliferative and apoptotic potential against human breast cancer cell lines (MCF-7)

Abstract

Interesting antimicrobial data from the stem bark of Sclerocarya birrea, which support its use in traditional medicine for the treatment of many diseases, have been delineated. The current study was aimed to further study some pharmacological and toxicological properties of the plant to scientifically justify its use. Anticancer activity of water and acetone extracts of S. birrea was evaluated on three different cell lines, HT-29, HeLa, and MCF-7 using the cell titre blue viability assay in 96-well plates. Apoptosis was evaluated using the acridine orange and propidium iodide staining method, while morphological structure of treated cells was examined using SEM. The acetone extract exhibited remarkable antiproliferative activities on MCF-7 cell lines at dose- and time-dependent manners (24 h and 48 h of incubation). The extract also exerted apoptotic programmed cell death in MCF-7 cells with significant effect on the DNA. Morphological examination also displayed apoptotic characteristics in the treated cells, including clumping, condensation, and culminating to budding of the cells to produce membrane-bound fragmentation, as well as formation of apoptotic bodies. The acetone extract of S. birrea possesses antiproliferative and apoptotic potential against MCF-7-treated cells and could be further exploited as a potential lead in anticancer therapy.

Figure 1

Effect of S. birrea acetone extract on proliferation of MCF-7, HT-29 and HeLa cells at 24 h. Each value represented mean ± SEM of six replicates (n = 6).

Figure 2

Effect of S. birrea acetone extract on proliferation of MCF-7 cells at 24 and 72 h. Each value represented mean ± SEM of six replicates (n = 6); *P < 0.05.

Figure 3

Agarose gel (1,5%) profile of DNA from MCF-7 cells treated with acetone extract of S. birrea. Effect of different concentrations of acetone extract (EA) after 24 h incubation. Lane 1: molecular weight marker, lane 2: untreated MCF-7 cells, note that cells were unaffected, lane 3: treated cells with IC₅₀ conc. DNA concentration diminishes with a visible faint band. Lane 4: treated cells with IC₅₀  ×  2 conc, faint band completely disappears; in subsequent lanes. Lane 5: treated cells with IC₅₀  ×  4 conc. Lane 6: treated cells with IC₅₀  ×  8 concentration.

Figure 4

Effect of S. birrea acetone extract on MCF-7 cells at 24 h and subjected to acridine orange (Life technology, South Africa) and propidium iodide staining. (a) Negative control of untreated cells depicting viable cells (green nucleus), (b) cells treated with positive control curcumin (60 μM), showing late apoptosis (thick arrow), (c) treated cells with IC₅₀ (87.6 μg/mL) concentration indicating early apoptosis (thin arrow), and (d) treated cells with IC₅₀  ×  4 showing late apoptosis and secondary necrosis.

Figure 5

Scanning electron micrographs: (a) untreated MCF7 cells (control), (b) MCF-7 cells treated with curcumin (60 μM) (positive control), note clumping and margination culminating to budding of the cells and formation of apoptotic bodies, (c) treated MCF7 cells in IC₅₀ concentration (87.6 μg/mL), (d) treated MCF7 cells in IC₅₀  ×  4 concentration note disintegration and blebbing. Apoptotic body (thin black arrow), thick white arrow, cell disintegration.