Background: Cancer is a major cause of death worldwide. Limitations of current cancer therapies necessitate the search for
new anticancer drugs. Plants represent an immeasurable source of bioactive compounds for drug discovery. The objective
of this study was to assess the anti-proliferative and antioxidant potential of four indigenous South African plants
commonly used in traditional medicine.
Materials and Methods: The anti-proliferative activity of the plant extracts were assessed by the 2,3-Bis-(2-Methoxy-4-Nitro-5-Sulfophenyl)-2H-Tetrazolium-5-Carboxanilide (XTT) assay on A431; HaCat; HeLa; MCF-7 and UCT-Mel 1 cells
and sulforhodamine-B (SRB) assay on HCT-116 and HCT-15 cell lines. Antioxidant activity was determined using the 2,
2-diphenyl-1-picrylhydrazyl (DPPH), nitric oxide (NO) and superoxide scavenging assays.
Results: Three of the plant extracts (
Combretum molle
fruit,
Euclea crispa subsp.
crispa
leaves and stems and
Sideroxylon inerme
leaves and stems showed anti-proliferative activity on the A431 cells with IC
50values ranging between 26.9 - 46.7
μg/ml. The
Euclea crispa subsp.
crispa extract also showed anti-proliferative activity on the MCF-7 cell line (45.7 μg/ml).
All of the plant extracts (
Combretum molle leaves and fruit,
Euclea crispa subsp.
crispa leaves and stems,
Sideroxylon
inerme leaves and stems and
Terminalia prunioides
leaves and stems) showed DPPH scavenging activity with IC
50 values
ranging from 1.8 μg/ml to 11.5 μg/ml.
Conclusion: These results indicate that the active extracts of
Combretum molle,
Euclea crispa subsp.
Crispa and
Sideroxylon inerme warrant further investigation to determine the mechanism of anti-proliferative activity against
cancerous cells. These plant extracts also show potential for further evaluation in the prevention and treatment of cancer.
