Activities of Some Medicinal Plants on the Proliferation and Invasion of Brain Tumor Cell Lines

Abstract

Cancer is a debilitating disease that is on the increase in both developed and developing countries. Anticancer drugs are often expensive, have narrow spectrum of activities, and are associated with toxicities and side effects such as myelosuppression, immunosuppression, gastrointestinal disturbance, alopecia, skin toxicity, and hepatotoxicity. Plants have been the major source of anticancer drugs both in orthodox and traditional medicine. Many of the plants claimed by the traditional medicine practitioners (TMPs) to be effective in the treatment of cancer are yet to be evaluated scientifically. In this work, five medicinal plants used by TMPs in Borno State, Nigeria, were tested against two brain tumor cell lines. Ethanol extracts of Securidaca longepedunculata, Andira inermis subsp. rooseveltii, Annona senegalensis, Carissa edulis, and Parinari polyandra were used. U87 and U231 brain tumor cell lines were used for proliferation assay, U251 cell line was used for the invasion assay in collagen V coated inserts, and U87 cell line was used for the western blot detection of cleaved Poly-ADP-Ribose-Polymerase (PARP). The result revealed that all tested extracts significantly (p < 0.05) inhibited the proliferation of U87 and U231 cell lines with the respective IC₅₀ values ranging between 8 and 20 μg/ml for S. longepedunculata and 100 and 90 μg/ml for P. polyandra. The five extracts significantly (p < 0.05) inhibited the invasion of U251 cell line at the concentration of 10 μg/ml (S. longepedunculata), 20 μg/ml (A. inermis), 50 μg/ml (A. senegalensis), 50 μg/ml (C. edulis), and 50 μg/ml (P. polyandra). Securidaca longepedunculata extract induced the cleavage of PARP. It was concluded that these medicinal plants have antiproliferative and anti-invasive activities and possess good prospects as source of anticancer agents especially S. longepedunculata which induced apoptosis in U87 cell line.

Figure 1

Effect of various plant extracts on the proliferation of U87. ^∗p < 0.05 compared with the control or PBS group. There is concentration-dependent inhibition by administration of S. longepedunculata extract 48 h after treatment on U87 cell lines. Significant (p < 0.05) antiproliferation is observed from 3 μg/ml on U87 and 10 μg/ml in U251 cell lines. PBS was used in S. longepedunculata, and DMSO (≤1:1000) was used in all other extracts. U87 cells were exposed to A. inermis at 25, 50, and 100 μg/ml with significant inhibition at 50 μg/ml. The concentrations are different from the one in the figure and could not be presented together.

Figure 2

Effect of various plant extracts on the proliferation of U251. ^∗p < 0.05 compared with the control or PBS group. There is concentration-dependent inhibition by administration of the extracts 48 h after treatment on U251 cell lines. Significant (p < 0.05) antiproliferation is observed from 10 μg/ml in by all extracts except P. polyandra which is at 100 μg/ml. PBS was used in S. longepedunculata, and DMSO (≤1:1000) was used in all other extracts.

Figure 3

Effect of various plant extracts on the invasion of U251 cell line. ^∗p < 0.05 compared with the control. All extracts inhibited invasion significantly (p < 0.05). Highest activities are in A. inermis and S. longepedunculata.

Figure 4

Effect of ethanol extracts S. longepedunculata, A. inermis, and A. senegalensis on induction of PARP protein in U87 cell line. PARP was cleaved in cells treated with S. longepedunculata root bark extract only.