Background: Dillenia indica L. (Dilleniaceae) and Anogeissus leiocarpus (DC.) Guill.
& Perr. (Combretaceae) are used in traditional Nigerian medicine to treat various forms of cancer.
This study investigated the cytotoxic effects of these plant extracts using COV434 granulosa tumor
and MCF-7 breast cancer cells.
Methods: Samples of D. indica and A. leiocarpus were collected in Ibadan, Nigeria, air-dried, and
extracted with methanol. Cell viability and cytotoxicity were determined using CellTiter-Glo® 2.0
assay at concentrations from 1 to 100 μg/mL. Caspase activity and apoptosis were determined using
Caspase-Glo® 3/7, Caspase-Glo® 8, and ApoTox-Glo™ triplex assays, and qPCR. Autophagy
was measured using a Cyto-ID Autophagy Detection Kit.
Results: In COV434, aqueous partitions of A. leiocarpus root (ALR-Aq) and stem bark (ALS-Aq)
had IC50s of 23.5 and 26.7 μg/mL, respectively. In MCF-7 cells, the ALR MeOH extract had IC50 of
12.75 μg/mL, while the DIS-Aq had IC50 of 65.28 μg/mL. None of the extracts inhibited the
growth of human osteoblasts or rat myoblasts at similar concentrations. Treatment with ALR-Aq
and DIS-Aq induced mitochondrial apoptosis in MCF-7 and COV434. Both ALR-Aq and DIS-Aq
induced autophagy in COV434 cells, while ALR-Aq induced autophagy in MCF-7 cells. Ellagic
acid (IC50 of 3.27μg/mL in COV434 cells) was isolated from ALR-Aq using bioassay-guided fractionation.
Conclusion: DIS-Aq and ALR-Aq induced apoptosis in MCF-7 and COV434 cancer cells. Ellagic
acid was isolated as the active constituent. Taken together, these data suggest that both plant extracts
have strong anti-proliferative effects, and further investigation for their anticancer effects is