The effects of indigenous South African plant extracts (Cotyledon orbiculata and Tulbaghia. Violacea) on triple negative breast cancer cells


Session type:


Mohammed Alaouna1,Rodney Hull2,Clem Penny3,Zodwa Dlamini4
1witwatersrand university,2Pretoria University,3University of the Witwatersrand,4University of Pretoria



Triple-negative breast cancer (TNBC) is characterised by the lack of receptors for oestrogen, progesterone, and human epidermal growth factor 2 . In South Africa TNBC primarily affects younger black females. This aggressive cancer has high relapse and mortality rates. The lack of hormone receptors renders current therapies ineffective. This study aimed to evaluate the ability of extracts from two indigenous South African plants, Tulbaghia  violacea and Cotyledon orbiculata on TNBC cell lines in vitro.


Aqueous and methanol extracts from both plants will be tested for cytotoxic activity against TNBC and normal breast cell lines. Active compounds will be purified from crude extracts of C. orbiculata and T. violacea that have cytotoxic or inhibitory effects on TNBC cells. Lead compounds will be selected based on their IC50 profiles. The effect of plant extracts on cancer-related processes, including cell adhesion, cell invasion and migration will be investigated. Changes in the miRNA profile of normal breast cells and TNBC cells treated with plant extracts will be determined using next-generation sequencing and validated using RT-PCR. Bioinformatic tools will be used to identify aberrant gene networks and associated signalling pathways.


Aqueous and methanol soluble extracts were successfully prepared. These extracts showed cytotoxic activity against the MDA-MB-231 cells. The IC50 of the crude extracts was established using Alamar and trypan Blue cell viability assays. The IC50 for T. violacea extracts was 70 µg/mL for water soluble and 110 µg/mL for methanol soluble. The IC50 determined for C.  orbiculate was 68 µg/mL for water soluble and 102 µg/mL for methanol soluble.


The crude plant extracts from both species have cytotoxic effects against the TNBC cell line and could contain potential lead compounds for the development of new drug therapies. Further purification and characterisation of these compounds is underway.