Magister Scientiae - MSc (Medical BioSciences)

Permanent URI for this collectionhttps://hdl.handle.net/10566/17104

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Exploring South African honey: a focus on chemical composition and antimicrobial activity against pathogenic organisms
(University of the Western Cape, 2025) Rohman Tanya; Abrantes Pedro
Honey has been used as an alternative medicinal agent for many years. Several factors give honey its antimicrobial ability including the presence of hydrogen peroxide, phenolic compounds, low moisture content, low pH, and high sugar concentrations. In South Africa, data on the antimicrobial activity of indigenous honey is limited, as there are many floral sources that are still underexplored. Additionally, very few studies highlight the influence that antimicrobial properties may have on the honey’s antimicrobial activity. The aim of this study was to investigate whether ten honey samples collected from different regions within South Africa possess antibacterial activity against clinically relevant pathogenic bacteria, namely Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli and Pseudomonas aeruginosa, and to determine whether the physicochemical properties of the honey samples collected influenced their antimicrobial activity. Samples were mainly collected from regions within the Western Cape and Northern Cape. The phenol equivalence assay was employed to assess antibacterial activity at honey concentrations ranging from 5 – 50% (w/v). Physicochemical properties were assessed, including moisture content, colour intensity, pH, and chemical composition. Results of this study revealed that S. aureus was the most susceptible bacterium and P. aeruginosa the least. Honey obtained from the Succulent Karoo region exhibited exceptional antibacterial activity, whereas most Graafwater region samples exhibited poor or no activity. Despite no statistical correlation being observed between the physicochemical properties and the antibacterial activity of the honey samples, all Succulent Karoo samples (Niewoudtville – Loeriesfontein and Vanrhynsdorp – Niewoudtville) possessed a high pH (4.36 and 4.59) and moisture content (4.42% and 8.39%) and were darkest in colour (211.89 mm and 323.27 mm) compared to other samples. Furthermore, 1H NMR analysis revealed that Succulent Karoo samples are chemically unique compared with other honeys, with unidentified resonances that could correspond to bioactive compounds. In conclusion, this study revealed that honey derived from the Succulent Karoo region in South Africa has the potential to be used therapeutically and provides insight on the chemical composition of South African honeys, contributing towards the chemical profile of South African flora
Exploring the in vitro effects of chronic Methamphetamine exposure on selected Cancer cell lines
(University of the Westen Cape, 2025) Sasman Sasha-lee; Willemse Chontrelle
Methamphetamine (METH) is a potent psychostimulant widely associated with neurotoxicity and oxidative stress. Although its acute effects are well documented in multiple organ systems, the cellular consequences of chronic METH exposure in cancer biology remain poorly defined. Understanding how tumour cells respond to sustained psychostimulant-induced stress may provide insight into metabolic and redox adaptations relevant to cancer progression. Five cancer cell lines, namely MCF-7, MDA-MB-231, HeLa, U87, and SK-N-BE-2 cancer cells were exposed to physiological and supraphysiological concentrations of METH (0.1-250μM) chronically for 96 hours. Cell viability and proliferation were assessed using the trypan blue exclusion assay. Mitochondrial activity was evaluated using the XTT assay. Intracellular reactive oxygen species (ROS) levels were quantified using the H₂DCFDA assay. All measurements were analysed relative to controls to identify dose- and time-dependent trends. Across all five cell lines, chronic METH exposure did not induce cytotoxicity, as dead cell numbers remained comparable to controls at all time points. Instead, METH produced cytostatic modulation varied by cell line and concentration. All lines exhibited delayed mitochondrial hyperactivity, suggesting potential metabolic compensation in response to sustained stress. ROS measurements revealed oscillatory redox dynamics, characterised by early ROS perturbations followed by significant ROS suppression at later time points, indicating activation of antioxidant responses. Collectively, the data show that cells respond to repeated METH exposure not by undergoing cell death but by adjusting proliferation, mitochondrial function, and redox homeostasis. Chronic methamphetamine exposure alters cancer cell types’ physiology differently through cytostatic, metabolic, and redox adaptation, rather than through direct cytotoxicity. These findings highlight the need for deeper mechanistic studies into how psychostimulant use may influence cancer cell behaviour, metabolic resilience, and stress-response pathways.
The implementation of in vitro assays to screen environmental samples for male reproductive toxicity
(University of the Western Cape, 2010) Ebrahim, Mozaffar
Endocrine–disrupting compounds (EDCs) are exogenous compounds/chemicals which interfere with, or have adverse effects on the production, distribution and function of natural hormones, thereby affecting normal endocrine activity, health and quality of life of both humans and wildlife. The reproductive system is highly susceptible to EDCs due to it being controlled by an array of hormonal signals. The effects of EDCs on the male reproductive system include infertility, decreased sperm count, function and morphology, abnormal development of secondary sex characteristics, reproductive function and sexual behaviour as well as decreased libido. There are various sources by which EDCs enter the environment which include effluents from several industries (mining, agriculture, smelting, hazardous waste sites, manufacturing industries, etc.), sewage treatment effluents, urban and agricultural runoff and effluents which include natural and pharmaceutical chemicals excreted in the urine of humans and domestic livestock, pesticides, polychlorinated biphenyls, dioxins, plasticizers, surfactants, etc. Humans and animals can also be affected by EDCs by consuming food containing endocrine active substances. The growing concern regarding adverse effects due to EDC exposure of humans and wildlife, as well as the increased incidence of EDC contamination has prompted extensive research into the development and validation of screening tests to detect and monitor known EDCs and new substances with endocrine-disrupting capability. These screening tests involve assessing the effect of known and potential EDCs on reproductive function and development as well as hormone production. To assess the effect of EDCs on the reproductive system different methods are employed which include in vitro, in vivo and ex vivo methods. In vitro methods have been suggested as a suitable screening tool for EDC monitoring due to low costs, reduced animal usage, the use of standard and basic equipment as well as the ability to screen a large number of samples with multiple endpoints. Of the available in vitro methods, the minced testes method has been suggested as the most suitable method for screening EDCs and for this reason has been employed in this study. The aim of this study was thus to employ a minced testes method to screen samples for male reproductive toxicity using cell viability and hormone production (testosterone and estradiol) as endpoints. The first objective of this study was to optimize an in vitro testicular cell culture assay by determining both optimal luteinizing hormone (LH) concentration and incubation time needed for testosterone production. Testicular cell cultures were prepared and cells were treated with varying concentrations of LH (10, 1, 0.1, 0.01 and 0 mu/ml) and incubated for 4 hours and 20 hours. Testosterone production was evaluated for each incubation period. Testosterone production was significantly increased for both incubation periods at all LH concentrations tested as compared to the control. For both incubation periods, there was no significant difference in testosterone production between the different LH concentrations tested. From the data obtained, the 4 hour incubation period as well as the LH concentration of 10 mu/ml were selected as optimal for the testicular cell culture assay. The second objective of this study was to determine the effect of Tulbaghia violacea Harv. on the male reproductive system. T. violacea is a plant species indigenous to southern Africa and is used locally as a herbal remedy/medicine to treat several ailments. Cells were treated with varying concentrations of the T. violacea ethanol extract (with/without LH-treatment) and incubated for 4 hours. Hormone production and cell viability were evaluated. The results obtained from this pilot in vitro study demonstrated that the ethanol extract of T. violacea has androgenic properties by significantly increasing LH-induced testosterone production in mouse testes with no significant change in cell viability. The third objective of this study was to assess the effect of Sutherlandia frutescens(L.) R.Br and Artemisia afra Jacq. Ex Willd. on the male reproductive system. S. frutescens and A. afra are also plant species indigenous to southern Africa and used locally as a herbal remedy/medicine to treat several ailments. Ethanol extracts of each plant was prepared and cells were treated with varying concentrations of each extract (0, 156.25, 312.5, 625, 1250, 2500 and 5000 µg/ml) with or without LH-treatment and incubated for 4 hours. Cytotoxicity by LDH measurement and hormone production (testosterone and estradiol) were endpoints that were evaluated. The results obtained showed that the ethanol extracts of both plants are not cytotoxic to testicular cells and that A. afra decreases testosterone production at high concentrations. The fourth and final objective of this study was to assess the acute effect of four heavy metals, namely manganese, copper, cadmium and magnesium on the male reproductive system. These heavy metals are used extensively in manufacturing and mining industries. Cells were treated with varying concentrations of each metal salt (200, 100, 50, 25, 12.5, and 6.25 µM) with or without LH-treatment and incubated for 4 hours. Endpoints evaluated included cell viability, testosterone and estradiol production. The results obtained showed that manganese, cadmium and copper are highly toxic to testicular cells in vitro and therefore may potentially cause reproductive toxicity.
An investigation of student engagement, learning strategies, and challenges in anatomy learning within the context of South African higher education: insights from Mind, Brain, and Education (MBE) Science
(University of the Western Cape, 2025) Fritz, Kaylyn Anastacia
Background: Human anatomy forms the basis of all undergraduate medical and health science degrees; however, the content-heavy nature of the discipline is often a challenge. Therefore, it is imperative that higher education institutions understand how students prefer to assimilate new information and adapt content delivery approaches to their unique experiences and needs in order to support academic success. Hence, in an effort to enhance the teaching and learning process, this research study aimed to investigate how student engagement, learning strategies, and challenges influenced the anatomy learning experience of first-year students at the University of the Western Cape (UWC). The Mind, Brain, and Education (MBE) Science theoretical framework was used to inform the study aims and objectives. Study design: Using a concurrent mixed-methods approach by means of an online Google Form questionnaire, qualitative and quantitative data were simultaneously collected and then analysed to draw comprehensive conclusions. The study examined independent variables including age, home language (HL), method of payment (MOP) for tuition fees, and degree programme in relation to the dependent variables including student engagement (access, use and preference) with pedagogical approaches, perceived effectiveness of pedagogical approaches, perceived benefits of pedagogical approaches, learning strategies, and perceived influences that affect the anatomy learning experience. Data was obtained from 126 participants (during 2022 - 2023) who were randomly assigned to the pilot study group (n = 20) and main study group (n = 106). All procedures were approved by the Humanities and Social Sciences Research Ethics Committee (HS21/10/38) at UWC. Main study results: Participants predominantly accessed and used the face-to-face theory lecture teaching method and the teaching slides (ppt/pdf) resources. They also preferred face-to-face teaching methods (theory lectures, 29.2%; practicals, 16.0%), and also found it to be more effective learning measures (theory lectures, 91.5%; practicals, 98.1%) than the alternative live online methods. In terms of teaching resources, the majority of participants preferred teaching slides (ppt/pdf) (10.4%) and found it to be an effective learning measure (92.5%). When studying anatomy, participants commonly made use of teaching slides (92.5%), narrated pre-recorded lectures (69.8%), and textbooks or e-textbooks (55.7%). Learning strategies such as spaced practice (27.4%, 3.70 ± 1.91) and elaboration (19.8%, 4.13 ± 1.40) were strongly preferred among participants.
Galenia africana extract as an alternative to typical azoles against Candida species
(University of the Western Cape, 2025) Mouton, Charnice Rene’
Candidiasis is a common infection caused by Candida species, often associated with immune compromised patients. Due to the prevalence of candidal resistance to typical azole treatments, alternative forms of therapies should be investigated. The use of medicinal plants as an alternative form of therapy has become a topic of interest in the scientific community. Galenia africana has shown a lot of potential as an antimicrobial plant extract. In this study, the antifungal activity of the ethanolic and ethyl acetate extraction of Galenia africana was investigated against fluconazole-resistant and susceptible Candida species. High-performance liquid chromatography and nuclear magnetic resonance were employed to separate, isolate and purify the active compounds of Galenia africana followed by evaluating the antifungal activity using broth microdilution, synergistic and time kill assays. Three compounds were isolated from Galenia africana, identified as (S)-5,7-dihydroxy flavone (1), (E)-2',4'-dihydroxychalcone (2), and (S)-2',5,7,-trihydroxyflavanone (3). The results showed significant antifungal activity below 500μg/ml which confirms that Galenia africana can be used as a potential antifungal against fluconazole resistant strains of Candida.
Aggregatibacter actinomycetemcomitans serotypes in gingival crevicular fluid of mothers delivering preterm.
(University of the Western Cape, 2024) Messeir, Ilze
Preterm birth (PTB), defined as delivery before 37 weeks of gestation, is a significant global public health concern. It has a tremendous impact on both the healthcare system and the individual families affected. Low birth weight (LBW), is a direct consequence of PTB or intrauterine growth restriction, and is a major determinant of neonatal infant morbidity and mortality. The primary aim of this study was to determine if the prevalence of Aggregatibacter actinomycetemcomitans (Aa) serotypes in gingival crevicular fluid (GCF) stored for more than ten years could be used as microbial biomarkers to predict preterm delivery. The study samples included 185 samples from “preterm birth” and “normal birth” mothers with pregnancy gingivitis.
Aspects of the interrelation between hypertension and insulin resistance: A preliminary study
(University of the Western Cape, 2024) Nwabuisi Osuafor, Godswill; Dietrich Daneel
It is well known that some genetic factors and dietary factors. such as excessive salt intake and excessive caloric intake (resulting in obesity) are risk factors for hypertension. Fifty percent of all hypertensive patients are also insulin resistant. Both hypertension and insulin resistance are again risk factors for other cardiovascular diseases such as atherosclerosis and heart fai lure. The nature of the association between hypertension and insulin resistance has not heen clearly elucidated. Spontaneously hypertensive rats are the ideal models to study the aspects of the relationships between hypertension and insulin resistance. Models of high-fat feeding induce obesity, hypertension and insulin resistance and are thus used extensively to study hypertension because these models closely mimic some of the renal and cardiovascular changes found in human hypertensive pati ents. The present study was initiated to evaluate if insulin resistance will develop within 6 weeks in a model of high- fat diet induced hypertension and if so. to determine whether captopril will affect the presence of insulin resistance. This model should in future be used to study vascular reactivity to phenylephrine (PHE), acetylcholinc (AC!-1) and sodium ni troprusside (S~P) in hypertensive animals in the absence or presence of insulin resistance and in normotensive insulin resistant animals.
Isolation and characterization of attachment-induced regulatory elements in Pseudomonas aeruginosa P AOI
(University of the Western Cape, 2024) Weyers Jakobus Barnad; Brozel V. S.
Bacteria exhibit a remarkable tendency to attached to biological (biotic) and abiological (dead) surfaces (Zobell. 1943). This tendency of bacteria to interact with surfaces appears to be increased or amplified under certain "stress" conditions. Environmental conditions implicated in promoting bacterial attachment and biofilm growth include nutrient limitation or starvation, increased osmolarity, membrane perturbation, and harmful chemicals (Costerton et al. , 1987; Marshall, 1992). In addition to environmental condition that enhance bacterial attachment. The interaction of bacteria with biotic surfaces appears to be very complex due to the interaction of prokaryotic and eukaryotic cell surface receptors with the host cell, and would therefore be very specific (Hoepelman and Tuomanen. 1992). The current body of data suggests that bacteria attach to surfaces under environmental ··stress·' conditions in order to cope better with the harsh environmental conditions. Attached bacteria would, therefore, have advantages over their planktonic counterparts during growth under environmental stress conditions. This is evident from reports stating that biofilms constitute major self purification systems with the abi lity to minimize the build-up of pollutants, transform inorganic compounds and biodegrade organic compounds (Marshall. 1992). Bacteria in biofilms are generally much more resistant to biocides and antibiotics than are their planktonic counterparts (Costerton et al., 1987). Attached bacteria have a protection barrier against phagocytosis, bacteriophages. antibiotics. biocides. surfactants and antibodies (Costerton et al .. 1995; Dooley and Trust, 1988; Sleyter and Messner, 1983).
The effects of water extracts on testosterone production in-vitro
(University of the Western Cape, 2012) Harribhai, Hitesh Ishwarlal; Pool, Edmund
The reproductive success of any species is dependent on the optimal functioning of both the male and female reproductive systems of that species. The male reproductive system is a highly intricate system that works interdependently with the endocrine system to maintain homeostasis. The system not only produces functioning male gametes, but is responsible for producing steroid hormones such as testosterone. The biosynthesis of testosterone involves multiple steps initiated by the stimulation of the Leydig cells in the testes by luteinising hormone. This biosynthetic pathway is highly susceptible to interference by substances mimicking the actions of the intermediate enzymes. These substances are referred to as endocrine disrupting chemicals (EDCs). These EDCs are found in high concentrations in wastewater. The city of Windhoek, Namibia, is an arid city where available surface and ground water resources do not meet domestic and industrial demands. To supplement Windhoek's water supply, the city started reclaiming water from the wastewater generated primarily from domestic sources.
Induction of metronidazole and clindamycin resistance in gardnerella vaginalis
(University of the Western Cape, 2023) Belford, Robyn Beth; Africa, Charlene
Bacterial vaginosis (BV) is known to be the most common polymicrobial vaginal disorder in females of childbearing age. It is characterised by a change in the healthy vaginal microbiome, from an environment dominated by hydrogen-producing lactobacilli, to the overgrowth of opportunistic pathogenic bacteria particularly Gardnerella vaginalis. G. vaginalis is a gram-variable pleomorphic bacterium which under normal conditions is considered to exhibit low virulence. G. vaginalis is the most common bacterial species isolated from patients with BV, and isolated in over 98% of BV cases. BV and other infections associated with G. vaginalis are typically treated with metronidazole or clindamycin. There has recently been an increase in recurrent BV infections and treatment failure. Antimicrobial resistance in bacteria has proven to lead to higher rates of adverse health outcomes. Understanding the susceptibility and resistance mechanisms of G. vaginalis is crucial in reducing the number of recurrent infections and treatment failures. Ten commercially acquired G. vaginalis type strains were tested in this study. The Kirby-Bauer and E-Test protocols were performed to determine the antibiotic susceptibility of selected strains and the minimum inhibitory concentrations (MIC) of metronidazole and clindamycin respectively.
The antioxidant potential of indigenous herbal extracts and their antimicrobial effect on human keratinocytes
(Universty of the Western Cape, 2023) Mpeke, Dimpho; Rahiman, Farzana
Medicinal plants are rich sources of antioxidants and due to their many biological properties, are used in the treatment and prevention of many skin-related conditions as alternative therapy to replenish and improve the skin’s barrier functions. Plant extracts produce secondary metabolites, known as phytochemicals which play an important role in their growth and development. These phytochemicals possess strong antioxidant and antimicrobial activities. Reactive oxygen species (ROS) play a pivotal role in the development of several allergic or inflammatory skin diseases. Antioxidants have the potential to counteract these ROS-induced effects, protecting the skin against free radicals. The purpose of this study was to determine the antioxidant potential of the hydroethanolic extracts of Galenia africana, Kigelia africana and Lessertia frutescens and their effect on the antimicrobial skin barrier.
The development of a sars-cov-2 pseudoparticle assay for the detection of neutralizing antibodies in sera from covid-19 patients
(University of the Western Cape, 2024) Daniels, Ame-Leigh; Shaw, Megan L.
The COVID-19 pandemic has caused devastating effects on the global socio-economic landscape. Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is the causative agent of COVID-19, and infections have led to approximately 7 million fatalities worldwide. Previous findings have confirmed that neutralizing antibodies are a highly predictive measure of immune protection. Thus, measuring SARS-CoV-2 neutralizing responses after infection or vaccination remains a priority, especially in the event of newly emerging SARS-CoV-2 variants. Due to the limitations of working with live virus in a BSL3 facility, pseudoparticles are an alternative tool used to study viral surface proteins. This research aims to develop a SARSCoV-2 pseudoparticle system to detect neutralizing antibodies in sera from previously infected or vaccinated individuals. The use of vesicular stomatitis virus (VSV) as a vector for the pseudoparticle system, provides several advantages over the lentivirus system including faster assay time, and lack of interference from antiretroviral drugs present in sera from HIVpositive patients on antiretroviral therapy (ART). The latter is particularly relevant in South Africa where there are more than 7.8 million HIV people living with HIV. After generating VSV pseudoparticles bearing the SARS-CoV-2 spike from the Wuhan/D614G, Beta, Delta and Omicron variants, a neutralizing assay was optimized using characterized human monoclonal antibodies. The assay was then applied to a sample set of patient sera and the ID50 values were compared to those obtained using a lentivirus-based SARS-CoV-2 neutralization assay. The comparison highlighted a strong concordance between the VSV and lentivirus neutralization assays particularly for the Wuhan/D614G and Omicron variants. The findings indicate that the development of a VSV-based neutralization assay is a valuable contribution to our ongoing efforts to characterize protective immune responses arising from SARS-CoV-2 infection or vaccination.
The phenomenon of skin lightening among young adults, and the effect of selected plant extracts on tyrosinase and melanogenesis activity
(University of the Western Cape, 2023) Opperman, Laurentia Joan; Rahiman, F Fisher
Skin lightening practice refers to the use of skin lightening products to achieve a fairer skin complexion. This is common practice among people of several Asian, North American, South American countries. On the African continent, the practice is popular in countries such as Nigeria, Togo, Senegal, Mali and South Africa. It has been reported that skin lightening products contain dangerous chemicals such as hydroquinone, mercury and steroids. The chronic use of these chemicals can lead to severe adverse effects such as skin irritations, skin infections and skin damage. Despite the health risks associated with this practice, demand and prevalence is on the rise as the global skin lightening industry is estimated to be worth USD 24 billion by 2027 and, thus, arises the need to identify less toxic alternatives. Africa`s forests are known as the world`s second largest tropical reservoir and holds significant biodiversity resources in which only 10.8% of its flora is known to be applied in traditional medicine. As the use of skin lightening agents are accompanied with the emergence of several complications, several studies have shown the use of natural plant extracts as a potential alternative with limited side effects to current synthesized skin lightening products. Plants are well known as an alternate treatment option for various ailments and the diversity of plants used in traditional medicine globally has been estimated between approximately 10 000 to 53 000 species. Considering the growing demand of skin lighteners which lead to an increase in the emergence of side effects and the alternative prospects presented by plant extracts, the overall aim of this study is to investigate the perceptions, knowledge and practice of skin lightening among young adults ata university within the Western Cape, South Africa. In addition, the study aims to evaluate the potential effect of plant extracts on melanin and enzyme tyrosinase activity on skin cells. The objectives were as follows: 1) to conduct a cross-sectional survey among male and female young adults aged 18 to 30 to explore their perceptions on skin lightening, 2) to conduct a comprehensive literature search on in vitro and in vivo studies to identify plant extracts capable of inhibiting melanogenesis and enzyme tyrosinase activity and 3) to assess the in vitro bio-activity of selected plant extracts on melanocytes.
The effect of doxorubicin encapsulated chitosan alginate nanoparticles and curcumin on multidrug resistant colon cancer cell lines
(University of the Western Cape, 2024) Audrey Masindi, Mutshidzi; Star, Khoza
Purpose: Although chemotherapeutic drugs have improved the survival rate of patients diagnosed with colorectal cancer, resistance to chemotherapy frequently leads to therapeutic failure and poor patient outcomes. Multidrug resistance (MDR) is a serious threat to cancer treatment efficacy and may be linked to the overexpression of drug efflux pumps. P-glycoprotein (P-gp) is a drug efflux transporter that triggers doxorubicin (DOX) resistance. This has led to an interest in chitosan alginate nanoparticles (CANPs) as novel anticancer drug carriers and curcumin (CUR) as an inhibitor of P-gp. Chitosan (CS) and alginate (ALG) are among the most extensively used polymers for nanoparticle (NP) preparation as they possess excellent non-toxic and biodegradable characteristics. The aim of this study was to investigate the effect of DOX encapsulated CANPs and CUR on MDR colon cancer cell lines (Caco-2 cells).
Dexamethasone's impact on LPS-induced inflammation of blood-brain barrier endothelial cells
(University of the Western Cape, 2023) Jeftha, Tershlin; Fisher, David
The blood-brain barrier (BBB) serves as a protective and regulatory barrier between the blood and the brain. Microvascular endothelial cells provide homeostatic regulation of the central nervous system (CNS). BBB integrity is compromised by inflammation, which contributes to a wide range of neurological disorders. It has been shown that glucocorticoids (GCs) have anti-inflammatory functions on a variety of cells. A particular example is Dexamethasone (Dex), which is used for the treatment of inflammatory conditions and has recently been found to be effective in attenuating COVID-19. Aim: The purpose of this study was to determine whether low or high concentrations of Dex can attenuate the inflammatory response induced by LPS on the in vitro BBB model.
In vitro neuroprotective potential of phyllanthin in MPP+- induced toxicity in SH-SY5Y neuroblastoma cells
(University of the Western Cape, 2023) Delport, Joshua; Ekpo, Okobi
Parkinson’s disease (PD) is the second most common age-related neurodegenerative disease after Alzheimer’s disease, with an estimated 9 million people projected to be affected worldwide by the year 2030. PD is associated with numerous motor symptoms such as tremor, bradykinesia (slowness of movements), hypokinesia (reduction in movement amplitude) and akinesia (absence of normal unconscious movements). However, in addition to these motor symptoms, several nonmotor manifestations are common, such as sensory symptoms (pain, tingling), hyposmia, sleep disturbance, depression, and cognitive impairment.
An evaluation of the biopesticidal characteristics of Helichrysum marifolium and Helichrysum patulum and their effects on animal metabolism
(University of the Western Cape, 2002) Speelman, Abigail; Johnson, Quinton
There are a number of pesticides that are suspected to be endocrine disrupters Many of these pesticides are man-made. Endocrine disrupters are chemicals that can lead to an increase in birth defects, sexual abnormalities, and reproductive failure. Marine animals seem to be the most vulnerable to the effects of pesticides since the ocean is the final sink for many pollutants. Endocrine disrupters can exert their effects in many ways. They can either bind to the hormone's receptor and mimic the hormone, or block the action of the hormone' An experiment done of newborn female rats injected with 1mg DDT/day on days 2-4 after birth had early onset of puberty and accelerated loss of fertility. In another experiment, vinclozolin (also a pesticide) at dosage levels of 3mg/kg/day resulted in feminized male rats in the womb, and an abnormal number of nipples were observed (11). Pesticides can be absorbed through the skin, by inhalation or oral ingestion. There are, however, important quantitative differences between the various derivatives. The skin poorly absorbs DDT in solution, whereas dieldrin absorption by the skin is very efficient. The major effects of insecticides in humans are qualitatively similar and cause effects on the central nervous system (9). Endocrine disrupters encompass more than just environmental estrogens and include any agent that adversely affects any aspect of the entire endocrine system. Endocrine disrupters are usually either natural products or synthetic chemicals that mimic, enhance, or inhibit the action of natural hormones (5). Low levels of many endocrine-disrupting chemicals can lead to high levels in the body tissues of animals and humans. This is due to the fact that many endocrine disrupters are stored in fat tissues through biomagnifications (2).
The effects of doxorubicin loaded chitosan-alginate nanoparticles on SK-N-BE(2) neuroblastoma cells
(University of the Western Cape, 2022) Rahman, Ziyaad; Hiss, Donavon
Cancer is a life-threatening disease and one of the leading causes of death globally. Cancer was thought to be associated with developed countries only but it is increasingly becoming a major health challenge in developing countries, including South Africa. Neuroblastoma is a form of cancer that affects the very early forms of nerve cells and is the most common extra-cranial solid tumour in children. It develops mainly in the adrenal medulla and the sympathetic ganglia. The focus of the present study is the development of a doxorubicin-loaded nanoparticle drug delivery system for the treatment of neuroblastoma. The biological diversity of the neuroblastic tumours that occur in patients has led to a divided approach in therapeutic strategies. Recent research efforts are aimed at designing therapies that will exploit the key oncogenic features of tumours, either within the tumours, in the tumour microenvironment, or both. Although doxorubicin chemotherapy is known to be generally very effective, previous studies have shown that it may result in the undesired toxicity of cardiomyocytes, cardiac fibroblasts, cardiac progenitor cells, endothelial progenitor cells, smooth muscle cells, and mesenchymal stem cells.
An electrophysiological exploration into the Sertoli cell, utilizing plant extracts with a view to contraception
(University of the western cape, 2003) Mosoval, Faisel; Fisher, D; Johnson, Q
Certa in medicinal plant extracts have been shown to have a contraceptive effect on male rats (Rajasekaran et al. , 1988) and mice (Kong et al., 1986). A possible site for the mechanism of action has been identified as the testis. The Sertoli cell s within the seminiferous tubules of the teste s are of fundamental importance to the developing sperm. These cells create a unique environment, which, without, would lead to the cessation of spermatogenesis (Gow et al. , 199 9). Know ledge of the Sertoli cell is thus essential in understanding the control of developing germ cells within the seminiferous tubules of the testis.
The influence of maternal nicotine exposure on neonatal lung development: An enzymatic and metabolic study
(University of the Western Cape, 1999) Kordom, Chontrelle; Martiz, G.S; de Kock, M
Chapter I, the literature review, gives the reader a sound background knowledge of the following: normal lung structural development in humans and rats, metabolic development with reference to structural development, tobacco smoke and nicotine and the effect of nicotine and smoking on metabolism. This will enable the reader to understand the motivation for this study and to give insight to the following chapters. Chapter II comprises the influence of maternal nicotine exposure on the enzymes, hexokinase and phosphofructokinase. The aim of this study was to determine the influence of maternal nicotine exposure during pregnancy and lactation on the enzymes involved in the control of energy metabolism of developing lungs of rats at postnatal days 1, 7,14,21 and 49. The objectives were to determine the effect of maternal nicotine exposure during gestation and lactation on, (a) the activity of selected allosteric enzymes, hexokinase (HK) andphosphofructokinase (PFK), (b) the influence of various ATP concentrations and ATP/ADP ratios within the reaction medium on the activity of these enzymes and (c) to express the activity of these enzymes as a function of age and (d) to correlate the findings with the stage of neonatal lung structural development as explained in the literature. Female Wistar rats were used in this study. The pregnant rats were randomly assigned as a control and an experimental (nicotine) group. The experimental dams received a single dosage of 1 mg nicotinel/ kg body weight/day subcutaneously and the controls received the same volume of saline. The enzymatic activity was determine by means of spectrophotometery. It was found that HK and PFK activity are age dependent.

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