Browsing by Author "Rahiman, Farzana"

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    Corrigendum: Immunological changes during space travel: A ground-based evaluation of the impact of neutron dose rate on plasma cytokine levels in human whole blood cultures
    (Frontiers Media, 2021) Fisher, Randall; Baselet, Bjorn; Rahiman, Farzana
    A better understanding of the combined impact of different space stressors on human health is urgently warranted, considering the upcoming long-duration missions beyond lower Earth orbit. Therefore, a growing number of particle accelerator facilities implement ground-based set-ups to study the effect of simulated space radiation with simulated psychological or physical stressors. The immune system is highly sensitive to these types of stressors and limited information is currently available on the impact of the complex space radiation environment on the astronauts’ immune function. This pilot study presents a first step in the implementation of a ground-based set-up with neutron irradiation, which is considered to be an important secondary component in space radiation fields. The effect of dose rate on immune alterations was studied using the in vitro cytokine release assay. Whole blood samples (n = 8) were exposed to 0.125 or 1 Gy of neutron irradiation (fluence-weighted average energy: 29.8 MeV) at a lower dose rate (LDR) of 0.015 Gy/min and a higher dose rate (HDR) of 0.400 Gy/min. Immediately post-irradiation, blood samples were stimulated with lipopolysaccharide (LPS), heat-killed Listeria monocytogenes (HKLM) or lectin pokeweed mitogen (PWM), and incubated for 24 h.
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    The effects of carbon-based nanoparticle surface functionalization on immune responses
    (University of the Western Cape, 2022) Salie, Imaad; Rahiman, Farzana
    Nano-based technologies are highly desired for the unique properties achieved through size restrictions. Nanoparticles (NPs) achieve a higher surface-to-volume ratio during synthesis. As a result there is a greater rate of interaction between the nanostructure, its surrounding environment, and the biological system it is present within. Research into nanomaterial effects on biological systems are imperative to control the functioning of these materials. A way of overcoming limitations and to meet end point goals within biological systems is the altering of nanomaterial surfaces for greater tolerance by cells.
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    The in vitro effects of artificial and natural sweeteners on the immune system using whole blood culture assays
    (Taylor & Francis, 2013) Rahiman, Farzana; Pool, Edmund John
    This article investigates the effects of commercially available artificial (aspartame, saccharin, sucralose) and natural sweeteners (brown sugar, white sugar, molasses) on the immune system. Human whole blood cultures were incubated with various sweeteners and stimulated in vitro with either phytohemagglutinin or endotoxin. Harvested supernatants were screened for cytotoxicity and cytokine release. Results showed that none of the artificial or natural sweeteners proved to be cytotoxic, indicating that no cell death was induced in vitro. The natural sweetener, sugar cane molasses (10 ug=mL), enhanced levels of the inflammatory biomarker IL-6 while all artificial sweeteners (10 ug=mL) revealed a suppressive effect on IL-6 secretion (P<0.001). Exposure of blood cells to sucralose-containing sweeteners under stimulatory conditions reduced levels of the biomarker of humoral immunity, Interleukin-10 (P<0.001). The cumulative suppression of Interleukin-6 and Interleukin-10 levels induced by sucralose may contribute to the inability in mounting an effective humoral response when posed with an exogenous threat.
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    Preliminary study on the effect of sugar cane (Saccharum officinarum) molasses on steroidogenesis in testicular cell cultures
    (Academic Journals, 2010) Rahiman, Farzana; Pool, Edmund John
    Blackstrap molasses has been used for centuries in the preparation of food products and have also been used to treat numerous ailments such as high blood pressure, arthritis, ulcers, dermatitits, eczema, constipation, colitis, varicose veins and many other health problems. Reports suggest that blackstrap molasses may have endocrine disruptive effects in cattle. The present study investigated the effect of sugar cane (Saccharum officinarium) molasses on steroidogenesis in testis cell culture. Testis cell cultures were incubated with various concentrations of molasses. Luteinizing hormone was used to stimulate the production of testosterone in the testes cell culture. Supernatants of the testes cell cultures were then assayed for testosterone, oestradiol and cytotoxicity using commercially available kits. Results showed that low concentrations (12 - 50 ug/ml) of molasses increase testosterone secretion relative to control cultures (P < 0.05). None of the molasses concentrations tested were cytotoxic. This study has shown that molasses stimulate testosterone production. Therefore, molasses may potentially be used as a diet supplement to increase testosterone levels.
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    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.
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    Tyrosol production of Candida species by plant extracts used for skin treatment remedies
    (University of the Western Cape, 2022) Heredia, Dario Gabriel; Rahiman, Farzana
    The fungal genus Candida is a collection of approximately 150 asporogenous yeast species which are able to cause life-threatening diseases when the normal host defences have been compromised. The most commonly isolated species is Candida albicans (C. albicans), which is a dimorphic fungus that exists in the blastopore and mycelial phase. Factors which are critical for the pathogenicity of Candida are morphological transition between yeast and hyphal forms, thigmotropism, biofilm formation, expression of adhesins, invasins on the cell surface and the secretion of hydrolytic enzymes such as phospholipases, proteases, and haemolysin.