Thesis (M. Sc. (Biochemistry)) -- University of Limpopo, 2021 / Plant-derived products have been used for years in the treatment of various ailments
with low or no side effects. Thus, screening of medicinal plants for potential
anticancer activity, in vitro, could help identify plant extracts or compounds that can
be developed for use as anticancer agents with less or no side effects. The aim of
this study was to investigate the probable anticancer effects and induced mechanism
of action of Momordica balsamina crude leaf acetone extract in lung A549 cancer
cells. The effect of the extract on cell viability, proliferation and cell division cycle
were determined using Muse count & viability, Ki67 proliferation and cell cycle assay
kits, respectively. The presence of biochemical and morphological features
associated with apoptosis were analysed by Muse annexin-V & dead cell assay kit
and Acridine orange/Ethidium bromide dual staining. The effect of the extract on the
mRNA expression levels of cell cycle regulatory genes was determined using RT PCR. Proteome profiler antibody array was used to determine the effect of the
extract on the protein expression levels of apoptosis regulatory genes. The findings
revealed that the crude leaf acetone extract of M. balsamina decreased the
percentage viability of lung A549 cells with less effect on the percentage viability of
normal cells (KMST-6). Furthermore, a significant anti-proliferative effect in extract treated A549 cells was observed. Characteristic nuclear and morphological features
of apoptosis such as chromatin and nuclear condensation, externalisation of
phosphatidylserine and loss of cell membrane function were observed in A549 cells
treated with the extract. Although there was no relative upregulation of Bax and Bad
protein expression, a downregulation of the Bcl-xl and Bcl-2 protein expression was
observed in extract-treated cells. This led to the release of Cytochrome c and
HTRA2/Omi leading to pro-caspase-3 cleavage. Furthermore, presence of
HTRA2/Omi in the cytosol inhibited the functions of IAPs such as XIAP and cIAP1/2.
Phosphorylation of p53 at different serine residues led to upregulated protein
expression levels of p27/Kip1 protein which resulted in the cell division cycle arrest
at G0/G1-phase. Reverse transcriptase polymerase chain reaction results showed
that the extract modulated mRNA expression levels of p53, p21, cyclin B and cdc2
genes. In summary, M. balsamina extract induced cell division cycle arrest and
apoptosis in A549 cells through intrinsic apoptosis pathway via p53-mediated
mechanism. / South African Medical Research Council (SAMRC)
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:ul/oai:ulspace.ul.ac.za:10386/3811 |
| Date | January 2019 |
| Creators | Mudalahothe, Maedza |
| Contributors | Mbazima, V. G., Poopedi, K. W. |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | xii, 67 leaves |
| Relation |
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