Abstract:
The rising costs of health care, the outbreak of drug resistant organisms, health
depleting lifestyles and the risky side effects of currently used drugs are world-wide
problems. This has led to the search for novel drugs and drug leads. Traditional
healers and other individuals across the globe possess unlimited knowledge on the
healing powers of different plants that has been passed on through generations. This
knowledge together with scientific investigations can lead to the eradication of most
of the diseases either by treatment or prevention.
Aloe ferox Mill. is one of the plants that have gained a lot of interest from the
pharmaceutical industry. The plant has over 80 documented medicinal uses. These
include treatment of impotence and infertility, sexually transmitted infections, arthritis,
hypertension, leukaemia, bacterial and fungal infections. It is also known as a blood
purifier, widely used as a laxative and anti- inflammatory agent. More research is
required to discover more about A. ferox and its benefits to health as well as to
investigate its potential for the development of novel drugs.
The current study was focused at investigating the anti- cancer, anti- microbial antidiabetic,
cytotoxic activities and phytochemical composition of leaf extracts of A.
ferox. Three cancer cell lines namely: breast (MCF7), colon (HCT116) and prostate
(PC3) cancer cell lines were used to investigate the anticancer activity of the extracts
using the Sulforhodamine B (SRB) method.
To determine the anti- diabetic activity of the plant extracts the C2C12 and Chang
cell in- vitro models of glucose uptake were used. The micro- dilution technique was
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used to evaluate the antibacterial and antifungal activity of the extract. The safety of
these extracts against normal human foetal lung fibroblasts (W138), Chang and
C2C12 cells was done by through the SRB and the MTT methods. To determine the
phytochemical profile of A. ferox the DPPH radical scavenging and the Folin
Ciocalteu methods were used to test the antioxidant activity and the total phenolic
content of the different extracts respectively. Different methods were used to
determine the presence of phytochemicals such as steroids, saponins, alkaloids,
carbohydrates and flavonoids. LCMS was also done to detect the elemental
composition of the plant extracts.
According to the CSIR criteria A. ferox was inactive against the cancer cell lines
used. It however exhibited antioxidant activity even at low concentrations, with an
EC50 of 0.865 ± 0.783. The methanol extract showed more phenolic content than
the dichloromethane and aqueous extracts at a concentration of 5mg/ml. It is
believed that the antioxidant activity correlates with the phenolic content and quality
of the phenols present in the plant and more assays have to be done to prove this
hypothesis. Other phytochemicals found in the extract included saponins, steroids,
alkaloids as well as flavonoids. Both the methanol and aqueous extracts of A. ferox
caused a significant increase in glucose uptake by C2C12 cells but caused a slightly
decreased uptake by the Chang cells. The plant extracts inhibited the growth of
Staphylococcus epidermidis, Streptococcus pneumonia, Escherichia coli and
Candida albicans at a concentration of 15mg/ml extract. Candida tropicalis and
Escherichia faecalis were resistant to A. ferox extracts. Finally the extracts showed
no toxic activity against the normal foetal lung fibroblasts, Chang and C2C12 cells
validating the safety of this plant for human use.
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The results in conjunction with literature findings show A. ferox to be a promising
source of drugs and therapeutic agents. Due to the fact that traditional healers
already rely on it as treatment for different ailments, it is important that the safety of
the plant for use has been validated though other studies and clinical trial still need
to be done to fully confirm this. All the information gathered also showed this plant to
be of great benefit against major health problems, responsible for millions of deaths
each year such as cancer, cardiovascular and inflammatory diseases, and diabetes.
There is however still a great need for more investigation to be done on this plant
against a vast majority of organisms and diseases so as to fully benefit from it.