Anti-Breast Cancer Properties Of Some Medicinal Plants In Ghana

ABSTRACT Cancer remains a killer disease worldwide and research into various anticancer agents must continue unabated to assuage the devastating effects of the disease. Medicinal plants have been utilised since antiquity to cure various ailments and plant species continue to serve as sources of prototypes for drug discovery. The study sought to screen Ghanaian traditional medicinal plants for their antiproliferative effect on MCF7 breast cancer cell line and determine the mechanism of induction of cytotoxicity. A total of 40 fractions comprising 14 fractions of ethyl acetate, 14 fractions of dichloromethane and 12 fractions of petroleum ether from 16 plant species were examined for their cytotoxic activity on MCF-7 breast cancer cell line using the MTT assay. Aqueous and 50% hydroethanolic extracts of M. oleifera were also examined analogously to evaluate their antioxidant activities. The results showed a dose dependent activity of the fractions on the breast cancer cell line with varying IC50 values. F. exasperata, P. pinnata, H. indicum, P. macrocarpus, A. melegueta, M. charantia, A. conyzoides, S. rotundifolius and A. cordifolia. were species that demonstrated the strongest cytotoxicity against the breast cancer cell line with IC50 values ranging from 3.8 µg/mL to 33.7 µg/mL with selectivity indices for most of the bioactive fractions > 2. The selectivity indices for the most bioactive fractions ranged from 1.5 to 10.5. O. gratissimum, F. aestuans, and A. zygia demonstrated moderate cytotoxicity with IC50 values of ranging from 41.9 µg/mL to 51.2 µg/mL. Aqueous and hydroethanolic extracts of M. oleifera showed no significant antiproliferative activities towards the MCF-7 breast cancer cells. The antioxidant activities of the aqueous and hydroethanolic extracts were 3.0 mg/mL and 3.1 mg/mL respectively indicating a good free radical scavenging property. The total phenolic content of the extracts were 177 mgGAE/g of extract and 168 mgGAE/g of extract for the aqueous and 50% hydroethanolic extracts, respectively. The selectivity indices of some of the bioactive fractions identified them as excellent candidates for further research and possible utilisation as drug leads. Some of the results also give empirical evidence as to the anecdotal use of the plants in folk medicine. Examination of the petroleum ether fraction of Aframomum melegueta demonstrated that apoptosis is induced as a mechanism of cytotoxicity.