Abstract:
Prostate and cervical cancers are among the leading cancer in men and women
respectively. The World Health Organization ranks cervical cancer as the fourth most
common cancer among women globally. The numbers are estimated to be 604,000 new
cases and 342,000 deaths in 2020. From this, about 90% of the new cases and deaths
worldwide in 2020 occurred in low and middle-income countries in the world (WHO,
2022). Current conventional cancer therapies like chemotherapy and radiotherapy present
severe side effects and in many developing countries are inaccessible to many cancer
patients. Traditional plant-based medicines have long been used to treat various diseases
as the plants are readily available. However, the inadequate understanding of the
therapeutic mechanisms at a cellular level has contributed to the growing difficulty of
bringing these drugs to conventional use. Using the MTT assay method, this study
investigated the anti-proliferative activity of methanol and water extracts from four plant
species- namely Aloe secundiflora, Maytenus obscura, Vernonia zanzibarensis and
Dichrostachys cinerea, against prostate cancer cells (Du145 and 22RV1), cervical cancer
cells (HeLa) and African green monkey (Vero) cell lines. The extracts studied suppressed
the growth of the cancer cells in a dose-dependent manner at concentrations of 1.37 µg/ml
to 1000 µg/ml. Extracts of V. zanzibarensis reported low antiproliferative activity against
DU145, 22RV1 and HeLa cell lines while the aqueous extract of M. obscura stem bark
and A. Secundiflora had moderate activity on DU145, 22RV1 and HeLa. The methanol
extract of D. cinerea stem bark had the highest anti-proliferative activity with an IC50 of
8.04 ± 2.8 µg/ml against the 22RV1 cells and a low cytotoxic effect against the Vero cells
with CC50 of 812.1 ± 12.72µg/ml. This study shows that the D. cinerea stem bark has
anti-proliferative activity with low cytotoxicity to normal cells. These results suggest that
the D. cinerea stem bark extract anti-proliferative activity can be linked to its ability to
up-regulate the expression of tumor suppressor gene p53. This was after analysis of p53
gene modulation by the D. cinerea stem bark extract which showed that the extract
upregulated the gene expression in Du145 cells by 1.76 folds. The conclusion of this study
details the survey literature of ethno medicinal uses and validates phytochemical profile
for management of cancer after an investigative focus to the synergistic pharmacological
effect in killing the cancer cells.