49 research outputs found
Chemical and biological evaluation of palythoa tuberculosa collected from the red sea
Masters of ScienceA chemical study on the total extract of the zoanthid Palythoa tuberculosa, collected
from the Red Sea, resulted in the isolation of seven polyhydroxylated sterols viz:
palysterols A-G, six of which are new. Their chemical structures were elucidated on the basis of their 1D and 2D NMR and MS spectroscopic data. Palysterols B and G
demonstrated cytotoxic activity on three human cancer cell lines (MCF-7, HeLa, and HT- 29). Palysterol G, in particular, was able to induce apoptosis in breast adenocarcinoma(MCF-7) cell
Controlled-Release Carbamazepine Matrix Granules and Tablets Comprising Lipophilic and Hydrophilic Components
The objective of this study was to investigate the effect of lipophilic (Compritol® 888 ATO) and hydrophilic components (combination of HPMC and Avicel) on the release of carbamazepine from granules and corresponding tablet. Wet granulation followed by compression was employed for preparation of granules and tablets. The matrix swelling behavior was investigated. The dissolution profiles of each formulation were compared to those of Tegretol® CR tablets and the mean dissolution time (MDT), dissolution efficiency (DE%), and similarity factor (f2 factor) were calculated. It was found that increase in the concentration of HPMC results in reduction in the release rate from granules and achievement of zero-order is difficult from the granules. The amount of HPMC plays a dominant role for the drug release. The release mechanism of CBZ from matrix tablet formulations follows non-Fickian diffusion shifting to Case II by the increase of HPMC content, indicating significant contribution of erosion. Increasing in drug loading resulted in acceleration of the drug release and in anomalous controlled-release mechanism due to delayed hydration of the tablets. These results suggest that wet granulation followed by compression could be a suitable method to formulate sustained release CBZ tablets
Green synthesis and characterization of gold nanoparticles from South African plants and their biological evaluations
Philosophiae Doctor - PhDThe field of nanotechnology continues to offer solutions for biotechnologists whose
target is to improve the quality of life by finding new therapies to combat diseases.
Gold nanoparticles (AuNPs) have been showing great potentials in many biomedical
applications. The antibacterial activity of the AuNPs presents a therapeutic option for
conditions caused by bacterial infections such as chronic wounds. Also, these versatile
particles can offer solutions in the treatments of infectious diseases and can also be
exploited as “smart” vehicles to carry drugs, such as antibiotics, for improved
efficiency. Moreover, the anti-inflammatory activity of AuNPs makes them useful in
the management of prolonged inflammation caused by bacterial infections.
The synthesis of AuNPs can be achieved by variety of physical and chemical methods
that have been successfully applied in labs and industry. Nonetheless, the drawbacks
of these “conventional” methods in terms of high cost, adverse health side effects and
incompatibility with the ecosystem cannot be overlooked. Thus, new safer and more
cost-effective protocols have been reported for the synthesis of AuNPs. Plants have
provided alternate synthesis methods in which the reducing capabilities of the
phytochemicals, found in the aqueous plant extracts, can be used to chemically
synthesize AuNPs from gold precursors.
The biosynthesis and characterization of AuNPs from the phytochemicals of several
South African plants is investigated in this study. The study also reports the
optimization of the AuNPs biosynthesis by varying reaction conditions such as
temperature and plant extracts’ concentrations. Furthermore, the study highlights the
wound healing activity of the AuNPs synthesized from selected plants by investigating
their antibacterial activity on bacterial strains known to cause chronic wounds. The
ability of these AuNPs to carry ampicillin in order to enhance the antibacterial activity
is also described herein. The cytotoxicity of the biosynthesized AuNPs was evaluated on human normal fibroblasts cells (KMST-6). Additionally, the immunomodulatory
effect of the biosynthesized AuNPs on the cytokines production from macrophages and
Natural Killer (NK) cells was examined.
The study was successful to produce biocompatible and safe AuNPs synthesized from
the tested aqueous plant extracts. The resulted AuNPs showed different
physicochemical properties by varying the reaction conditions. The AuNPs exhibited
antibacterial activity against several Gram-positive and Gram-negative bacteria. Also,
ampicillin was successfully loaded on the biosynthesized AuNPs, which led to the
formation of more antibacterial active conjugated AuNPs compared to the free AuNPs.
The green synthesized AuNPs were also found to have anti-inflammatory responses as
shown by the reduction of pro-inflammatory cytokines from immune cells. In vitro
assays showed that the biogenic AuNPs were not toxic to KMST-6 cells. Overall, the
data suggest that plant extracts produce biologically safe AuNPs with antibacterial and
anti-inflammatory activities that can be exploited in the treatment of chronic wounds
and in the management of chronic inflammation
Inhibition of bacteria associated with wound infection by biocompatible green synthesized gold nanoparticles from South African plant extracts
Unlike conventional physical and chemical methods, the biogenic synthesis of gold
nanoparticles (GNPs) is considered a green and non-toxic approach to produce biocompatible
GNPs that can be utilized in various biomedical applications. This can be achieved by using
plant-derived phytochemicals to reduce gold salt into GNPs. Several green synthesized GNPs
have been shown to have antibacterial effects, which can be applied in wound dressings to prevent
wound infections. Therefore, the aim of this study is to synthesize biogenic GNPs from the South
African Galenia africana and Hypoxis hemerocallidea plants extracts and evaluate their antibacterial
activity, using the Alamar blue assay, against bacterial strains that are known to cause wound
infections. Additionally, we investigated the toxicity of the biogenic GNPs to non-cancerous human
fibroblast cells (KMST-6) using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT)
assay. In this paper, spherical GNPs, with particle sizes ranging from 9 to 27 nm, were synthesized
and fully characterized. The GNPs from H. hemerocallidea exhibited antibacterial activity against all
the tested bacterial strains, whereas GNPs produced from G. africana only exhibited antibacterial
activity against Pseudomonas aeruginosa. The GNPs did not show any significant toxicity towards
KMST-6 cells, which may suggest that these nanoparticles can be safely applied in wound dressings
Reports of plant-derived nanoparticles for prostate cancer therapy
Plants have demonstrated potential in providing various types of phytomedicines with
chemopreventive properties that can combat prostate cancer. However, despite their promising
in vitro activity, the incorporation of these phytochemicals into the market as anticancer agents
has been hindered by their poor bioavailability, mainly due to their inadequate aqueous solubility,
chemical instability, and unsatisfactory circulation time. To overcome these drawbacks, it has been
suggested that the incorporation of phytochemicals as nanoparticles can offer a solution. The use
of plant-based chemicals can also improve the biocompatibility of the formulated nanoparticles
by avoiding the use of certain hazardous chemicals in the synthesis, leading to decreased toxicity
in vivo. Moreover, in some cases, phytochemicals can act as targeting agents to tumour sites. This
review will focus on and summarize the following points: the different types of nanoparticles that
contain individual phytochemicals or plant extracts in their design with the aim of improving the
bioavailability of the phytochemicals; the therapeutic evaluation of these nanoparticles against
prostate cancer both in vitro and in vivo and the reported mode of action and the different types of
anticancer experiments used; how the phytochemicals can also improve the targeting effects of these
nanoparticles in some instances; and the potential toxicity of these nanoparticles
Role and merits of green based nanocarriers in cancer treatment
The use of nanocarriers for biomedical applications has been gaining interests from researchers
worldwide for the delivery of therapeutics in a controlled manner. These “smart” vehicles
enhance the dissolution and the bioavailability of drugs and enable their delivery to the target
site. Taking the potential toxicity into consideration, the incorporation of natural “green” materials,
derived from plants or microbial sources, in the nanocarriers fabrication, improve their safety and
biocompatibility. These green components can be used as a mechanical platform or as targeting
ligand for the payload or can play a role in the synthesis of nanoparticles. Several studies reported
the use of green based nanocarriers for the treatment of diseases such as cancer. This review article
provides a critical analysis of the different types of green nanocarriers and their synthesis mechanisms,
characterization, and their role in improving drug delivery of anticancer drugs to achieve
precision cancer treatment. Current evidence suggests that green-based nanocarriers can constitute
an effective treatment against cancer.The National Research Foundation of South Africa and the South African Medical Research Council (SAMRC).https://www.mdpi.com/journal/cancersam2022Internal Medicin
The antimicrobial and anti-inflammatory effects of silver nanoparticles synthesised from cotyledon orbiculata aqueous extract
Cotyledon orbiculata, commonly known as pig’s ear, is an important medicinal plant of South
Africa. It is used in traditional medicine to treat many ailments, including skin eruptions, abscesses,
inflammation, boils and acne. Many plants have been used to synthesize metallic nanoparticles,
particularly silver nanoparticles (AgNPs). However, the synthesis of AgNPs from C. orbiculata has
never been reported before. The aim of this study was to synthesize AgNPs using C. orbiculata
and evaluate their antimicrobial and immunomodulatory properties. AgNPs were synthesized and
characterized using Ultraviolet-Visible Spectroscopy (UV-Vis), Dynamic Light Scattering (DLS) and
High-Resolution Transmission Electron Microscopy (HR-TEM)
Role and merits of green based nanocarriers in cancer treatment
The use of nanocarriers for biomedical applications has been gaining interests from researchers worldwide for the delivery of therapeutics in a controlled manner. These “smart” vehicles
enhance the dissolution and the bioavailability of drugs and enable their delivery to the target
site. Taking the potential toxicity into consideration, the incorporation of natural “green” materials,
derived from plants or microbial sources, in the nanocarriers fabrication, improve their safety and
biocompatibility. These green components can be used as a mechanical platform or as targeting
ligand for the payload or can play a role in the synthesis of nanoparticles. Several studies reported
the use of green based nanocarriers for the treatment of diseases such as cancer. This review article
provides a critical analysis of the different types of green nanocarriers and their synthesis mechanisms, characterization, and their role in improving drug delivery of anticancer drugs to achieve
precision cancer treatment. Current evidence suggests that green-based nanocarriers can constitute
an effective treatment against cancer
Large Scale Screening of Southern African Plant Extracts for the Green Synthesis of Gold Nanoparticles Using Microtitre-Plate Method
The preparation of gold nanoparticles (AuNPs) involves a variety of chemical and physical methods. These methods use toxic and environmentally harmful chemicals. Consequently, the synthesis of AuNPs using green chemistry has been under investigation to develop eco-friendly nanoparticles. One approach to achieve this is the use of plant-derived phytochemicals that are capable of reducing gold ions to produce AuNPs. The aim of this study was to implement a facile microtitre-plate method to screen a large number of aqueous plant extracts to determine the optimum concentration (OC) for the bio-synthesis of the AuNPs. Several AuNPs of different sizes and shapes were successfully synthesized and characterized from 17 South African plants. The characterization was done using Ultra Violet-Visible Spectroscopy, Dynamic Light Scattering, High Resolution Transmission Electron Microscopy and Energy-Dispersive X-ray Spectroscopy. We also studied the effects of temperature on the synthesis of the AuNPs and showed that changes in temperatures affect the size and dispersity of the generated AuNPs. We also evaluated the stability of the synthesized AuNPs and showed that some of them are stable in biological buffer solutions
Role of precision oncology in type II endometrial and prostate cancers in the African population : global cancer genomics disparities
Precision oncology can be defined as molecular profiling of tumors to identify targetable
alterations. Emerging research reports the high mortality rates associated with type II endometrial
cancer in black women and with prostate cancer in men of African ancestry. The lack of adequate
genetic reference information from the African genome is one of the major obstacles in exploring the
benefits of precision oncology in the African context. Whilst external factors such as the geography,
environment, health-care access and socio-economic status may contribute greatly towards the
disparities observed in type II endometrial and prostate cancers in black populations compared to
Caucasians, the contribution of African ancestry to the contribution of genetics to the etiology of these
cancers cannot be ignored. Non-coding RNAs (ncRNAs) continue to emerge as important regulators
of gene expression and the key molecular pathways involved in tumorigenesis. Particular attention
is focused on activated/repressed genes and associated pathways, while the redundant pathways
(pathways that have the same outcome or activate the same downstream effectors) are often ignored.
However, comprehensive evidence to understand the relationship between type II endometrial
cancer, prostate cancer and African ancestry remains poorly understood. The sub-Saharan African
(SSA) region has both the highest incidence and mortality of both type II endometrial and prostate
cancers. Understanding how the entire transcriptomic landscape of these two reproductive cancers
is regulated by ncRNAs in an African cohort may help elucidate the relationship between race and
pathological disparities of these two diseases. This review focuses on global disparities in medicine,
PCa and ECa. The role of precision oncology in PCa and ECa in the African population will also
be discussed.This research was funded by the South African Medical Research Council (SAMRC) Grant No. 23108 and the National Research Foundation (NRF) Grant No. 138139.The South African Medical Research Council and the National Research Foundation.https://www.mdpi.com/journal/ijerphMedical OncologyUrolog