Browsing by Author "Gouws, Chrisna"
Now showing items 1-20 of 24
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Absorptive and secretory transport of selected artemisinin derivatives across Caco-2 cell monolayers
Heyns, Jaco; Willers, Clarissa; Haynes, Richard K.; Wong, Ho N.; Hamman, Josias; Gouws, Chrisna (Bentham Science, 2018)Background: Malaria continues to be a major health concern and affects more than 200 million people a year. Drugs currently used for treatment of malaria are increasingly rendered ineffectual by the ongoing emergence of ... -
Aloe vera gel and whole leaf extract: functional and versatile excipients for drug delivery?
Laux, Alex; Gouws, Chrisna; Hamman, Josias H. (Taylor & Francis, 2019)Aloe vera (L.) Burm.f. (Aloe barbadensis Miller) is a perennial xerophyte plant that has many medicinal applications. A. vera leaves contain water storage tissue, which is fundamentally made up of a viscous mucilage contained ... -
Assessing the DNA methylation status of single cells with the comet assay
Wentzel, Johannes F.; Gouws, Chrisna; Huysamen, Cristal; Van Dyk, Etresia; Koekemoer, Gerhard; Pretorius, Pieter J. (Elsevier, 2010)The comet assay (single cell gel electrophoresis) is a cost-effective, sensitive, and simple technique that is traditionally used for analyzing and quantifying DNA damage in individual cells. The aim of this study was to ... -
Cell-free DNA in a three-dimensional spheroid cell culture model: a preliminary study
Aucamp, Janine; Calitz, Carlemi; Bronkhorst, Abel J.; Hamman, Sias; Gouws, Chrisna; Pretorius, Piet J. (Elsevier, 2017)Background Investigating the biological functions of cell-free DNA (cfDNA) is limited by the interference of vast numbers of putative sources and causes of DNA release into circulation. Utilization of three-dimensional ... -
Characterization of an alginate encapsulated LS180 spheroid model for anti-colorectal cancer compound screening
Smit, Tanya; Calitz, Carlemi; Willers, Clarissa; Svitina, Hanna; Hamman, Josias; Gouws, Chrisna; Wrzesinski, Krzysztof (ACS, 2020)Colorectal cancer is one of the leading causes of cancer-related deaths. A main problem for its treatment is resistance to chemotherapy, requiring the development of new drugs. The success rate of new candidate cancer drugs ... -
Combination therapy of western drugs and herbal medicines: recent advances in understanding interactions involving metabolism and efflux
Gouws, Chrisna; Steyn, Dewald; Du Plessis, Lissinda; Steenekamp, Jan; Hamman, Josias H. (Taylor & Francis, 2012)Introduction: While complementary and alternative medicine markets prosper with an increasing number of consumers of herbal medicines, there is an associated likelihood for herb–drug interactions to occur. Modulation of ... -
Combining chemical permeation enhancers for synergistic effects
Du Toit, Trizel; Malan, Maides M.; Lemmer, Hendrik J.R.; Gouws, Chrisna; Aucamp, Marique E.; Breytenbach, Wilma J.; Hamman, Josias H. (Springer, 2016)Currently, macromolecular drugs such as proteins are mainly administered by means of injections due to their low intestinal epithelial permeability and poor stability in the gastrointestinal tract. This study ... -
Efflux as a mechanism of antimicrobial drug resistance in clinical relevant microorganisms: the role of efflux inhibitors
Willers, Clarissa; Wentzel, Johannes Frederik; Du Plessis, Lissinda Hester; Gouws, Chrisna; Hamman, Josias Hendrik (Taylor & Francis, 2017)Introduction: Microbial resistance against antibiotics is a serious threat to the effective treatment of infectious diseases. Several mechanisms exist through which microorganisms can develop resistance against antimicrobial ... -
Enhancing the solubility and in vitro permeability of pyrimethamine
Heunis, F.J. (North-West University (South-Africa), 2021)ABSTRACT Malaria poses a substantial health problem, with nearly half of the world’s population susceptible to it. Malaria causes an estimated one million deaths per year. People who fall prey to malaria are also burdened ... -
Evaluation of isolated fractions of aloe vera gel materials on indinavir pharmacokinetics: in vitro and in vivo studies
Wallis, Lonette; Malan, Maides; Gouws, Chrisna; Steyn, Dewald; Ellis, Suria; Hamman, Josias; Otto, Daniel P. (Bentham Science, 2016)Aloe vera is a plant with a long history of traditional medicinal use and is consumed in different products, sometimes in conjunction with prescribed medicines. A. vera gel has shown the ability to modulate drug absorption ... -
Evaluation of the efficacy of selected anticancer compounds in multidrug resistant cell culture models
Rossouw, Michael Jacques (North-West University (South-Africa). Potchefstroom Campus, 2019)Small cell lung cancer (SCLC) has an aggressive disseminating nature and the relapse of cancer patients after initial treatment is common. Acquired multidrug resistance (MDR) can often be attributed to over-expression of ... -
Herb-drug pharmacokinetic interactions: transport and metabolism of indinavir in the presence of selected herbal products
Calitz, Carlemi; Gouws, Chrisna; Viljoen, Joe; Steenekamp, Jan; Hamman, Josias (MDPI, 2015)Patients receiving anti-retroviral drug treatment are sometimes simultaneously taking herbal remedies, which may result in pharmacokinetic herb-drug interactions. This study aimed to determine if pharmacokinetic interactions ... -
Herbal hepatotoxicity: current status, examples, and challenges
Calitz, Carlemi; Du Plessis, Lissinda; Gouws, Chrisna; Steyn, Dewald; Steenekamp, Jan; Muller, Christo; Hamman, Sias (Taylor & Francis, 2015)Introduction: Herbal medicines have commonly been considered safe by the general public due to their natural origin and long history of traditional uses. In contrast to this belief, many plants produce toxic substances as ... -
Impact of traditional African medicine on drug metabolism and transport
Calitz, Carlemi; Steenekamp, Jan H.; Steyn, Johan D.; Gouws, Chrisna; Viljoen, Joe M.; Hamman, Josias H. (Taylor & Francis, 2014)Introduction: Africa is a continent of rich plant biodiversity with many indigenous plants having a long history of being used for medicinal purposes. A considerable number of patients consult traditional healers in ... -
In vitro evaluation of the efficacy of selected medicinal plant extracts against multidrug resistant cancer cells
Swanepoel, Roan Albertus (North-West University (South-Africa). Potchefstroom Campus, 2019)Cancer is ranked as one of the leading causes of death globally, and a significant number of these diagnosed malignancies are found in lung tissue. Small cell lung cancer (SCLC) is a high grade neuroendocrine cancer, which ... -
Isolation and in vitro permeation of phenylpropylamino alkaloids from Khat (Catha edulis) across oral and intestinal mucosal tissues
Atlabachew, Minaleshewa; Hamman, Josias H.; Gouws, Chrisna; Combrinck, Sandra; Viljoen, Alvaro M. (Elsevier, 2016)Ethnopharmacological relevance: Khat, the leaves of Catha edulis, is used as a “natural amphetamine-like” stimulant in eastern and southern Africa, as well as in the Arabian Peninsula. Leaves are masticated to elicit a ... -
Modifying the comet assay for measuring global DNA methylation in a variety of tissue cells
Wentzel, Johannes Frederik (North-West University, 2010)It is becoming abundantly clear that DNA methylation plays a crucial role in gene regulation and that aberrant regulation of DNA methylation influences the development of certain diseases such as cancer. Although a wide ... -
Novel non-invasive protein and peptide drug delivery approaches
Wallis, Lonette; Kleynhans, Elmarie; Du Toit, Trizel; Gouws, Chrisna; Steyn, Dewald; Steenekamp, Jan; Viljoen, Joe; Hamman, Josias (Bentham Science, 2014)Protein and peptide based therapeutics are typically administered by injection due to their poor uptake when administered via enteral routes of drug administration. Unfortunately, chronic administration of these drugs ... -
O6-methylguanine-DNA methyltransferase (MGMT): can function explain a suicidal mechanism?
Gouws, Chrisna; Pretorius, Pieter J. (Elsevier, 2011)Why does O6-methylguanine-DNA methyltransferase (MGMT), an indispensable DNA repair enzyme, have a mechanism which seems to run counter to its importance? This enzyme is key to the removal of detrimental alkyl adducts from ... -
Recent advances in three-dimensional cell culturing to assess liver function and dysfunction: from a drug biotransformation and toxicity perspective
Calitz, Carlemi; Hamman, Josias H.; Gouws, Chrisna; Fey, Stephen J.; Wrzesinski, Krzysztof (Taylor & Francis, 2018)The liver is a vital organ fulfilling a central role in over 500 major metabolic functions, including serving as the most essential site for drug biotransformation. Dysfunction of the drug biotransformation processes may ...