Theses and Dissertations (Life and Consumer Sciences)https://hdl.handle.net/10500/31642024-03-29T02:29:38Z2024-03-29T02:29:38ZSupramolecular modification of isoniazid : an in vitro and in silico analysis of combination drug efficacy against mycobacteria speciesSetshedi, Itumeleng Bridgettehttps://hdl.handle.net/10500/309382024-03-13T08:33:37Z2023-10-12T00:00:00ZSupramolecular modification of isoniazid : an in vitro and in silico analysis of combination drug efficacy against mycobacteria species
Setshedi, Itumeleng Bridgette
Tuberculosis was for the longest of time a leading infectious killer instigated by a single pathogen until the emergence of SARS-CoV-2. The disease continues to be a major global health problem causing high rates of morbidity and mortality. Unfortunately, both the estimated disease incidence and mortality related to tuberculosis infections have been reported to be on the rise as treatment of the disease has been neglected due to a shift in attention to address the COVID-19 global pandemic. The remnants thereof still pose a direct negative impact on tuberculosis diagnosis and treatment, resulting in the partial reversal of any progress that had been made in the quest to end tuberculosis prior to the global COVID-19 pandemic. It is presumed that the challenges around tuberculosis treatment and misdiagnosis are as a result of the continuous ability of the pathogen to evade the host’s immune system and development of resistance against tuberculosis drugs. However, diagnosis seems to be the weakest link contributing to delayed treatment thereof.
If detected early, tuberculosis can be cured. However, if tuberculosis is not detected, it definitely cannot be treated; and, if it cannot be treated, it certainly cannot be eradicated. In addition, there is also an emergence of nontuberculous mycobacteria which are caused by mycobacteria species other than those belonging to the Mycobacterium tuberculosis complex. Some of these organisms cause pulmonary infections indistinguishable to those caused by M. tuberculosis infections, presenting with pulmonary and extrapulmonary tuberculosis-like diseases. The prevalence of these diseases has steadily gained traction in recent years, reported and isolated from clinical isolates around the world. Yet, these mycobacteria are not targeted when screening for tuberculosis in clinical isolates. This is a public health problem as nontuberculous mycobacteria are generally resistant to the tuberculosis treatment regimen used in screening assays and if not screened, they can easily be misdiagnosed as Mycobacterium tuberculosis. If there are no obvious ways in which these organisms can be distinguished during diagnosis, it would be beneficial if drugs that are designed could target both Mycobacterium tuberculosis and nontuberculous mycobacteria as nontuberculous mycobacteria are not susceptible to first- and second-line tuberculosis treatment regimens.
The aim of this study was to design and synthesise isoniazid derivatives that are effective against clinically infectious Mycobacterium tuberculosis as well as nontuberculous mycobacteria isolates. To achieve this, methods such as the one-pot reflux method were
employed for the synthesis of the isoniazid derivative. Crystallographic data were collected using the Bruker APEX II CCD area detector diffractometer. Data were reduced and corrected using the SAINT-Plus software and the SADABS software, respectively. Diagrams were generated using WinGX and PLATON software. To test for the efficacy of the derivatives against mycobacteria of choice (M. tuberculosis H37Ra, M. bovis BCG, M. smegmatis, M. avium and M. fortuitum) in comparison to the efficacy of isoniazid and that of rifampicin, a number of disciplines with varying techniques were employed and these include microbiology, where minimum inhibitory concentration experiments were conducted, and cell biology where cell viability was assessed using real-time cell analysis techniques and flow cytometry analysis conducted using the xCELLigence RTCA system and the BD FACSArai™ III cell sorter, respectively. The potential safety of these compounds was also assessed on RAW 264.7 murine macrophage cells where methods such as the MTT assay and real-time cell analysis assay as well as flow cytometry assay (Muse® Cell Analyzer) were employed to conduct cell viability assessment. Lastly, molecular docking and modelling experiments were conducted to determine the target protein and binding of the ligands thereof (protein-ligand binding).
Unit cells were collected for all nineteen synthesised derivatives, where nine have been previously synthesised and ten were found to be novel. Of the ten, six were refined successfully and five of those published in peer-reviewed journals. All derivatives were screened against mycobacteria of choice and only a few were found to have inhibitory effects against some of the mycobacteria with some noteworthy concentrations varying between 0.25 μg/mL and 11.36 μg/mL as single compounds, and 0.09 μg/mL and 0.59μg/mL for combination drug treatments. Isoniazid was comparable against single and combination derivatives with concentrations ranging between 3.9 μg/mL and 22.73 μg/mL, and rifampicin gave competitive results at concentrations ranging between 0.16 μg/mL and 15.65 μg/mL against single and derivatives. In most cases, the derivatives were observed to cause direct apoptotic effects on mycobacterial cells at competitive percentages of between 59% and 90%, thus better than the apoptosis percentage induced by isoniazid and rifampicin of less than 10%. Nonetheless, the related apoptosis results were in accordance with RTCA and flow cytometry results that saw most derivatives posing less toxicity against murine macrophage cells and the ability of the said cells to recover as compared to when exposed to isoniazid and rifampicin. The molecular modelling results also saw a few molecules and combinations possessing exceptional binding abilities with the catalase-peroxidase enzyme with no degree of displacement and good drug residence time, thus suggestive of some derivatives being effective mycobacteria inhibitors targeting the catalase-peroxidase enzyme with docking scores ranging from -4.879 kcal/mol, -5.390 kcal/mol, to -6.065 kcal/mol.
2023-10-12T00:00:00ZExpression, purification, and characterisation of the Alpha-helical and Beta-sheet domains of Rotavirus VP6Strachan, Milaanhttps://hdl.handle.net/10500/308222024-02-15T11:31:11Z2023-08-20T00:00:00ZExpression, purification, and characterisation of the Alpha-helical and Beta-sheet domains of Rotavirus VP6
Strachan, Milaan
The capsid protein VP6 is of paramount importance to the stability and infectivity of Rotaviruses. Through interactions of VP6s’ beta-sheet (VP6) and alpha-helical (VP6) domains with the viral particle's outer- and innermost layers, respectively, VP6 stabilises matured Rotaviruses and activates transcription of the viral genome upon cell entry. This study focused on the individual domains of Rotavirus VP6. The aim of the study was to probe the structure and stability of VP6 and VP6 when expressed independently of each other. The objectives of the study were: (1) optimise the bacterial expression of VP6 and VP6 through modulation of the expression conditions (2) solubilise and then purify the domains by immobilised metal chromatography (IMAC), (3) characterise by means of spectroscopy (mass spectroscopy, far-UV circular dichroism (CD), and intrinsic tryptophan fluorescence spectroscopy) and gel electrophoresis (native-PAGE), the primary, secondary, tertiary, and quaternary structures of the domains, (4) characterise the conformational stability by means of spectroscopy (far-UV CD and intrinsic tryptophan fluorescence) of VP6 and VP6 when thermally and chemically challenged, and (5) determine the melting temperature by differential scanning calorimetry (DSC). To this end, two Escherichia coli strains BL21(DE3) and NiCo21 (DE3) were transformed with pET15a plasmids containing the codon-optimised DNA consensus sequences of VP6 and VP6. The expression of VP6 and VP6 was done at different temperatures (37°C and 20°C), inducer concentrations (1 × and 10 × IPTG), and post-induction incubation times (2 h – 7 h, and 16 h) in both E. coli strains and the outcomes were visualised by SDS-PAGE. All conditions tested produced the domains in an insoluble form and though expression levels appeared to be comparable between strains, the NiCo21 (DE3) was ultimately selected for further expression of the domains as expression could be induced with the lowest concentration of IPTG. The insoluble domains were subjected to a solubilisation study where the domains were frozen in various Tris-HCl buffers differing in pH (7 – 10) and urea concentration (0 M, 2 M, and 5 M) and thawed. The results of the solubilisation study showed that both domains could effectively be solubilized in 2 M urea, provided that the pH of the freezing buffer was at least one unit higher than the pI of the domain. The solubilised VP6 and VP6 were purified by nickel affinity chromatography in yields of 13.32 mg and 25 mg from 1 L of NiCo21 (DE3) culture, respectively and were confirmed by mass spectroscopy, far-UV CD, and intrinsic tryptophan fluorescence spectroscopy, to have native-like sequences and structural features. The quaternary analysis revealed that VP6 existed as a single monomeric species in solution while VP6 formed different-sized structures in solution. The conformational stability of VP6 and VP6 was demonstrated as the domains had resisted structural changes up to 46°C and 50°C, respectively and the DSC analysis revealed melting points of 67.94°C for VP6 and 68.55°C for VP6. The domains were noted to aggregate extensively which prevented the recovery of their native structures upon cooling. The chemical unfolding study was done in 1 M – 5 M guanidine hydrochloride (GdCl) and 1 M – 8 M urea, and revealed the chemical stability of the domains and their respective unfolding pathways. Approximately 1.5 M and 2.25 M GdCl were needed to denature 50% of VP6 and VP6, respectively. Urea concentrations of 4.5 M (VP6) and 4 M (VP6) also resulted in a 50% loss of native structures. The observation of non-cooperative unfolding pathways that differed between the spectroscopic probes suggested a complex unfolding process involving the formation of one or more intermediates. Though native-like structures could be recovered upon denaturant removal, the refolding and unfolding pathways differed, which was indicative of irreversibility. Overall, VP6 and VP6 were easily producible and purifiable in quantities suitable for further studies. Further investigations could highlight the potential applications the domains could have in vaccine development and drug-delivery. Non-cooperative folding indicated the necessity of interactions between VP6 and VP6 in the full-length protein for cooperative folding.
2023-08-20T00:00:00ZAn integrated attitude-intention model describing the essence of South African consumer attitudes toward UHT milk alternative productsWassenaar, Anjolizehttps://hdl.handle.net/10500/305682023-10-24T10:20:35Z2023-01-01T00:00:00ZAn integrated attitude-intention model describing the essence of South African consumer attitudes toward UHT milk alternative products
Wassenaar, Anjolize
While various factors such as health conditions, lifestyle trends and special nutritional requirements create increased consumer interest in the UHT milk alternative category, little is known about the South African market and the meaning consumers ascribe to these products. This remains a hindrance to marketing strategies and the development of products which meet consumer requirements. The industry needs to understand what influences consumer decisions to purchase products in this unique category. The purpose of the study was to gather deeper insights into the essence of South African consumer attitudes toward UHT milk alternatives and their related purchase intentions.
The research utilised a postpositivist, qualitative approach to shape the perspective of the exploratory-descriptive phenomenological study. The geographical location of the study was within the borders of South Africa, to gather insight from South African consumers shopping in the South African retail market. The original research plan was to gather data through in-person mini-focus groups. Due to the coronavirus disease of 2019 (COVID-19) pandemic restrictions on in-person meetings implemented during the data-gathering phase of the research, data-gathering methods were continued online rather than in person. The study used two in-person mini-focus groups, eight online mini-focus groups and eleven semi-structured online interviews, collecting data from 35 participants. Participants for the in-person mini-focus groups were initially recruited from the UNISA Main and Florida campuses via the university’s internal email communication network. However, due to limitations placed on in-person meetings during the COVID-19 pandemic and a change to online mini-focus groups and semi-structured interviews, the recruitment strategy was expanded to requests for participation posted on social media (Facebook) for individuals with a potential interest in milk alternatives. Participants in both recruitment strategies were self-selected by choosing to participate or not in the online mini-focus groups and booking a timeslot using the online SignUp Genius platform. Individuals who could not join the timeslots of online mini-focus groups were accommodated with semi-structured online interviews. The number of participants was not pre-determined, instead, participant recruitment and data-gathering concluded once a point of saturation was established from the new insights gathered from the thematic data analysis.
A discussion guide was used to initiate discussions during data-gathering activities. The discussion was guided by the research questions and objectives. The same discussion guide was used for the mini-focus groups and semi-structured interviews. The questions were used as a guideline only to initiate discussions to maintain the emergent design of the study and enough flexibility to explore new concepts which arose during the discussions.
Questions from the discussion guide were occasionally rephrased and follow-up questions were formulated during the discussions to adapt to and expand on new insights as provided by participants, allowing the research to continue in its emergent design.
The research proposal, including the research methodology, was approved by the Ethics Committee of the College of Agriculture and Environmental Science at the University of South Africa for approval before the study commenced and adhered to during the entire research process. The trustworthiness of the findings was supported by credibility, transferability, dependability, confirmability and reflexivity. Data was analysed using an inductive-deductive thematical analysis approach. During the inductive thematic analysis phase, data was analysed to find the emerging codes, subthemes and themes. A deductive thematic analysis phase followed the inductive phase to verify that the data supported the subthemes and themes found during the first phase and that any gaps or duplications of themes were addressed. Once a point of saturation was reached, as determined by the number, or lack of, new insights gained with each participant response, data-gathering activities were concluded.
Findings were described, visualising the links between themes and subthemes which collectively shape consumer attitudes and purchase intentions toward UHT milk alternative products within the South African market. Meaningful links were discovered from the multiple participant perspectives, developing a complex representation of the factors involved in their purchase intentions. Consumer product-related attitudes specifically focused on the participant’s meaning ascribed to the product category, were comprised of the consumer product beliefs and their evaluation of the product, with all its supporting sub-themes. Non-product-related attitudes, such as attitudes toward expected outcomes, the social norm and control, were also found to impact consumers’ purchase intentions. The research found that none of the factors could be used in isolation to describe participant attitudes and purchase intentions. These attitudes and intentions must be considered holistically for the essence of South African consumer attitudes toward UHT milk alternative products and purchase intentions to be understood, leading to the development of the Integrated Attitude-Intention Model. The proposed Integrated Attitude-Intention Model was developed to visually depict the impact of consumer product beliefs (cognitive attitude component) and evaluation of product (affective attitude component), collectively suggested to be product-related attitudes, as well as expected outcomes, the social norm and control (cognitive attitude component), collectively suggested shaping non-product-related attitudes, on consumer purchase intentions.
The research contributions include practical recommendations to industry to provide insight for product development and marketing strategies, as well as contributions to theory through the proposed model, addressing gaps in the body of literature and contributing to research methodology. Limitations of the study were indicated as applicable to theory, the research design and methodology and in context of the interpretation and application of the research findings. Finally, recommendations for future research were presented to expand on the depth of understanding through further qualitative research, as well as testing and confirming research findings further through quantitative research.; Le hoja dintlha tse fapaneng tse kang maemo a bophelo bo botle, mekgwa ya bophelo le ditlhoko tse kgethehileng tsa phepo di baka thahasello e eketsehileng ya bareki sehlopheng sa mefuta e meng ya lebese la UHT, ha ho tsejwe hakaalo ka mmaraka wa Afrika Borwa le moelelo wa bareki ba dihlahiswa tsena. Sena e ntse e le tshitiso ho maano a papatso le ntshetsopele ya dihlahiswa tse fihlelang ditlhoko tsa bareki. Indasteri e hloka ho utlwisisa hore na ke eng e susumetsang diqeto tsa bareki ho reka dihlahiswa tsa mofuta ona o ikgethang.Sepheo sa thuto e ne e le ho bokella dintlha tse tebileng mabapi le moelelo wa maikutlo a bareki ba Afrika Borwa mabapi le mefuta e meng ya lebese la UHT le merero ya bona ya ho reka.
Diphuphutso di sebedisitse mokgwa wa ho totobatsa dintlha tse hlokomelehang tsa boleng ho bopa pono ya thuto e hlalosang seo batho ba fetileng ho sona. Thuto ena e sebedisitse dihlopha tse pedi tsa batho, dihlopha tse robedi tsa inthaneteng tse tsepamisitseng maikutlo ho inthanete le dipuisano tse tebileng tsa inthanete tse leshome le motso o le mong, ho bokelletswe dintlha ho tswa ho bankakarolo ba 35. Tataiso ya dipuisano e ile ya sebediswa ho qala dipuisano mme ya fetolwa ho latela moralo o hlahang wa dipatlisiso. Botshepehi ba diphumano bo ne bo tshehetswa ke ho tshepahala, ho fetiswa, ho tsitsa ha dintho tse fumanweng, ho tiisa, le ho ananela karolo e nkilweng dipatlisisong. Dintlha di ile tsa manollwa ho sebediswa mokgwa wa ho tlisa-ho beha diqeto ka mabaka ho hlalosa mekgwa ya moelelo ka hara dintlha tsa boleng. Diphumano di ile tsa hlaloswa, ho bontsha dikamano dipakeng tsa dihlooho le dihloohwana tse amang maikutlo a bareki ka kopanelo le merero ya ho reka mabapi le dihlahiswa tse ding tsa lebese la UHT ka hara mmaraka wa Afrika Borwa.
Dihokelo tse nang le morero di ile tsa sibollwa ho tswa mekgweng e mengata ya ditjhebo tsa bankakarolo, ho ntshetsapele boemedi bo rarahaneng ba dintlha tse amehang mererong ya bona ya ho reka. Maikutlo a bareki a ne a tsepamisitse maikutlo haholo moelelong wa bankakarolo o tsamaellanang le sehlopha sa sehlahiswa, a ne a entswe ka ditumelo tsa sehlahiswa sa bareki le tlhahlobo ya bona ya sehlahiswa, le dihloohwana tsohle tse tshehetsang.Maikemisetso a theko ya bareki hangata a ne a tsepamisitswe dinthong tse sa amaneng le sehlahiswa, jwalo ka diphetho tse lebelletsweng, tlwaelo ya setjhaba le taolo, tse ileng tsa ama merero ya ho reka ya bareki. Leha ho le jwalo, merero ya ho reka e ile ya angwa haholo ke maikutlo a bareki mabapi le sehlahiswa ka bosona.Diphuphutso di fumane hore ha ho le ha e le nngwe ya dintlha tse ka sebediswang ka thoko ho hlalosa maikutlo a bankakarolo le merero ya ho reka. Maikutlo le maikemisetso ana a tlameha ho nahanwa ka botlalo molemong wa maikutlo a bareki ba Afrika Borwa
mabapi le dihlahiswa tse ding tsa lebese la UHT le maikemisetso a ho reka hore a utlwisiswe, e leng se lebisang ho ntshetsopele ya Mokgwa o Kopanetsweng wa Boikutlo ba Bareki.; Nakuba izici ezihlukahlukene njengezimo zempilo, izitayela zokuphila kanye nezidingo ezikhethekile zokudla okunomsoco kudala intshisekelo ekhulayo yomthengi esigabeni esihlukile sobisi lwe-UHT, kuncane okwaziwayo ngemakethe yaseNingizimu Afrika kanye nencazelo abathengi abayibeka ngale mikhiqizo. Lokhu kusalokhu kuyisithiyo kumasu okumaketha kanye nokuthuthukiswa kwemikhiqizo ehlangabezana nezidingo zabathengi. Imboni idinga ukuqonda ukuthi yini enomthelela ezinqumeni zabathengi zokuthenga imikhiqizo kulesi sigaba esiyingqayizivele. Inhloso yocwaningo bekuwukuqoqa imininingwane ejulile mayelana nengqikithi yesimo sengqondo sabathengi baseNingizimu Afrika maqondana nezinye izindlela zobisi lwe-UHT kanye nezinhloso zalo zokuthenga ezihlobene.
Ucwaningo lusebenzise indlela yokuhumusha iqiniso ngokwezibalo, echazayo ukuze ilolonge umbono wocwaningo lokuqala emcabangweni wombono. Lolu cwaningo lusebenzise amaqembu amabili okugxilwa kuwo kumuntu, amaqembu ayisishiyagalombili agxile ku-inthanethi anabahlanganyeli abambalwa kanye nezingxoxo ezijulile eziyishumi nanye eziku-inthanethi, ukuqoqa imininingwane kubahlanganyeli abangama-35. Umhlahlandlela wokuxoxisana wasetshenziswa ukuqalisa izingxoxo futhi washintshwa ngokuvumelana nomklamo wocwaningo oluvelayo. Ukwethembeka kokutholakele kusekelwe ngukukholeka, ukudluliswa, ukwethembeka, ukuqinisekiswa, kanye nokuvumelana nezimo. Imininingwane yahlaziywa kusetshenziswa indlela yokuhlaziya evumela imininingwane inqume indikimba kanye nesekelwe olwazini olukhona. Okutholakele kwachazwa, kubukwa ngeso lengqondo lokuxhumana phakathi kwezindikimba nezindikimba zesibili ezakha ngokuhlangene izimo zengqondo zabathengi kanye nezinhloso zokuthenga mayelana nemikhiqizo yobisi lwe-UHT ehlukile phakathi kwemakethe yaseNingizimu Afrika.
Izixhumanisi ezibalulekile zitholwe emibonweni yabahlanganyeli abaningi, ukuthuthukisa ukumelwa okuyinkimbinkimbi kwezinto ezibandakanyekayo ezinhlosweni zabo zokuthenga. Izimo zengqondo zabathengi ezigxile ngokukhethekile encazelweni yomhlanganyeli eshiwo esigabeni somkhiqizo, bekuhlanganiswa izinkolelo zomkhiqizo wabathengi kanye nokuhlola kwabo umkhiqizo, nazo zonke izingqikithi zesibili ezisekelayo. Izinhloso zokuthenga kwabathengi zazivame ukugxila ezintweni ezingahlobene nomkhiqizo, njengemiphumela elindelekile, inkambiso yomphakathi nokulawula, okube nomthelela ezinhlosweni zokuthenga zabathengi. Kodwa-ke, izinhloso zokuthenga nazo zathintwa kakhulu yisimo sengqondo somthengi ngomkhiqizo ngokwawo. Ucwaningo luthole ukuthi azikho izici ezingasetshenziswa zodwa ukuchaza izimo zengqondo
ix
zabahlanganyeli kanye nezinhloso zokuthenga. Lezi zimo zengqondo nezinhloso kufanele zibhekwe ngokuphelele ukuze kubhekwe ingqikithi yesimo sengqondo sabathengi baseNingizimu Afrika mayelana nemikhiqizo ehlukile yobisi lwe-UHT kanye nezinhloso zokuthenga ukuze ziqondwe, okuholela ekuthuthukisweni Kwesifanekiso Sesimo Sengqondo Somthengi Esididiyelwe.
2023-01-01T00:00:00ZThe effects of acute energy drink consumption on the cardiovascular system of University StudentsNyalela, Ayanda Nompumelelohttps://hdl.handle.net/10500/305072023-09-18T13:18:11Z2023-01-01T00:00:00ZThe effects of acute energy drink consumption on the cardiovascular system of University Students
Nyalela, Ayanda Nompumelelo
Introduction: Among the changes in dietary behaviour in South Africa is the increased consumption of energy drinks (EDs), shown to affect the cardiovascular system (CVS) due to high caffeine and bioactive compound concentrations. Cardiovascular disease (CVD) is a concern, especially in black cohorts with a reported high prevalence of hypertension, as increased consumption highlights the adverse effects of EDs on the CVS. Aim: This study’s aim was to determine the effects of acute ED exposure on the CVS of generally healthy, black, male university students. Methodology: A randomised, controlled, cross-over study was conducted on 26 male students aged between 18-29 years. A Monster® carbonated ED (intervention) and a diluted fruit juice concentrate with carbonated water (placebo) were administered to participants in a single-blinded manner on two non-consecutive days. Heart rate (HR; bpm) and blood pressure (BP; mmHg) were measured twice on the left arm of participants using an automated BP monitor. Measurements were recorded at 0-; 10-; 30-; 60-; 90-; and 120-minutes. Questionnaires were used to obtain demographical data and assess ED and caffeine usage. Results: Self-reported consumption frequency for caffeinated beverages was predominantly ≥14 servings/week (50%). The reported purpose for caffeine consumption was attributed to mainly academic purposes (61.5%). The preferred caffeinated beverage was EDs (77%). For ED consumption relative to baseline, systolic and diastolic BP were higher from 30-minutes (p<0,001 and p=0,015, respectively), HR was reduced at 10-minutes (p=0,015), while pulse pressure and MAP were increased from 30-minutes (p=0,043 and p<0,001). Following placebo consumption, blood pressure remained stable relative to baseline with BP reaching maximum values at 120-minutes. Although overall HR dropped below baseline in both groups over the study period, HR increased much later in the placebo group compared to the ED group, reaching its lowest point at 90-minutes, which in contrast, was the peak time point for ED consumption. For ED consumption relative to the placebo, BP was higher at all time points from baseline (p<0,001), while HR showed a significant increase at 90-minutes (p<0,001). Pulse pressure and MAP were higher for ED consumption, with significance observed at 90-minutes (p<0,001) for pulse pressure, and at all time points for MAP. The study found that drink type had a significant effect on BP (p<0,001) and a partial significance on HR (p=0,052). The interaction between drink type and time points had a significant effect on systolic BP
v
(p<0,001) and MAP (p<0,001) and a partial significance on diastolic BP (p=0,057). Conclusion: EDs significantly increased BP over a period of 2-hours relative to the placebo. These observations can be attributed to the sympathomimetic actions of the bioactive contents of EDs, especially as a result of the synergy between caffeine and taurine. Heart rate decreased slower in the ED group versus the placebo group which presented more stability. These changes can be attributed to caffeine’s stimulatory effects as well as its half-life in an adult body.; Inleiding: Die verhoogde inname van energiedrankies (ED’s) maak deel uit van Suid Afrikaners se dieet. Daar is bevind dat ED’s vanweë hulle hoë kaffeïeninhoud en
bioaktiewe verbinding konsentrasies die kardiovaskulêre stelsel (KVS) affekteer.
Kardiovaskulêre siektes is veral onder swart mense rede tot kommer gesien die
nadele wat die verhoogde inname van ED’s vir die KVS inhou. Oogmerk: Die oogmerk
van hierdie studie was om vas te stel watter uitwerking ’n akute inname van ED’s op
die KVS van gesonde swart manlike universiteitstudente het. Metodologie: Altesame
26 manlike studente tussen 18 en 29 jaar het aan hierdie ewekansige, beheerde
oorkruisstudie deelgeneem. ’n Monster®-ED (ingryping) en ’n vrugtesapkonsentraat
verdun met sodawater (plasebo) is op twee nieopeenvolgende dae volgens die
enkelblindmetode aan deelnemers toegedien. Hulle hartklop (HK; bpm) en bloeddruk
(BD; mmHg) is twee keer met ’n geoutomatiseerde sfigmomanometer aan die
linkerarm gemeet. Meterlesings is na 0; 10; 30; 60; 90 en 120 minute aangeteken.
Deelnemers se demografiese data en inname van ED’s en kaffeïen is met behulp van
vraelyste bepaal. Bevindings: Die self-gerapporteerde innamefrekwensie van
kaffeïendrankies was oorwegend ≥14 porsies/week (50%). Volgens die deelnemers
het ’n hoë kaffeïeninname hulle beter laat studeer (61,5%). ED’s was hulle
gunstelingkaffeïendrankie (77%). Vir die inname van ED met betrekking tot die
aanvangsmeting was die sistoliese en diastoliese BD ná 30 minute hoër (p<0,001 en
p=0,015 onderskeidelik), HK ná 10 minute stadiger (p=0,015), terwyl polsdruk en
gemiddelde arteriële druk (GAD) ná 30 minute hoër (p=0,043 en p<0,001). Vir ED inname met betrekking tot die plasebo was BD op alle metingstye hoër as die
aanvangsmeting (p<0,001) en was HK ná 90 minute beduidend hoër (p<0,001).
Polsdruk en GAD was hoër ná ED-inname. Beduidendheid is veral vir polsdruk ná 90
minute (p<0,001) en vir GAD op alle metingstye waargeneem. Die studie het bevind
dat die soort drankie ’n beduidende effek op BD (p<0,001) en ’n gedeeltelike
beduidende effek op HK gehad het (p=0,052). Die wisselwerking tussen die soort
drankie en die metingstye het ’n beduidende effek op sistoliese BD (p<0,001) en GAD
(p<0,001), maar ’n gedeeltelike beduidendheid op diastoliese BD (p=0,057) gehad.
Gevolgtrekking: ED’s het BD met betrekking tot die plasebo oor ’n tydperk van twee
uur beduidend laat styg. Ofskoon HK gedaal het, was waardes vir ED hoër met
betrekking tot die plasebo. Hierdie waarnemings kan toegeskryf word aan die
vasostimulant en simpatomimetiese werking van die bioaktiewe inhoud van ED’s as
gevolg van veral die sinergie tussen kaffeïen en tourien.; Intshayelelo: Phakathi kweenguqu ezenzekileyo eMzantsi Afrika kwindlela yokutya
kukunyuka kokusetyenziswa kweziselo ezinika amandla (iziselo ezinika
Amandla,EDs), eziboniswa zichaphazela inkqubo yemithambo yentliziyo (CVS)
ngenxa ye-khafini (caffeine) eninzi kunye nomxube oyingqumbululu wezinto
ezisebenzayo (bioactive). Isifo semithambo yentliziyo (CVD) yinkxalabo, ngakumbi
kumaqela abantu abamnyama, njengoko ukwanda kokusetyenziswa kuveza
imiphumo emibi yeziselo ezinika amandla (ED) kwimithambo yentliziyo (CVS).
Injongo: Injongo yolu phononongo yayikukuveza imiphumo yeziselo ezinika amandla
eziyingozi kwinkqubo yemithambo yentliziyo (CVS) kubafundi abangamadoda
abantsundu baseyunivesithi abasempilweni ngokubanzi.Indlela. yokwenza:
Uphononongo olulawulwe ngokungakhethiyo olunqamlezileyo lwenziwe kubathathi nxaxheba abaneminyaka ephakathi kwe-18 kunye ne-29. I-Monster® isiselo esinika
Amandla esinekharbon (carbonated ED) (ungenelelo) kunye nengqumbululu yencindi
engxengiweyo kunye namanzi anekharbon (i-placebo) inikezelwe kubathathi nxaxheba ngendlela eyodwa kwiintsuku ezimbini ezingalandelelaniyo. Isantya
sokubetha kwentliziyo (HR; bpm) kunye noxinzelelo lwegazi (BP; mmHg) zilinganiswe
kabini kwingalo yasekhohlo yabathathi-nxaxheba kusetyenziswa isixhobo
esizihambelayo i-sphygmomanometer. Imilinganiselo yarekhodwa kwi-0; 10; 30; 60;
90 kunye 120 yemizuzu. Imibuzo yayisetyenziselwa ukufumana idatha yabantu
bendawo ethile ngokwamanani neemeko zabo kunye nokuhlola i-ED (iziselo ezinika
Amandla) kunye nokusetyenziswa kwe-khafini (caffeine). Iziphumo: Izihlandlo
zokusetyenziswa njalo kweziselo ezinekharbon ubukhulu becala zazine ≥14
ngokokuphaka / ngeveki (50%). Ukusetyenziswa kwekhafini kwabalelwa kwiinjongo
zemfundo (61.5%). Esona siselo sikhethwayo esinekhafini yayiyisiselo esinika
amandla i-EDs (77%). Ukusetyenziswa kwesiselo esinika amandla (ED)
ngokuthelekswa nesiseko, uxinzelelo lwegazi xa intliziyo iqala ukumpompa igazi
(systolic BP) kunye noxinzelelo lwegazi xa intliziyo iyeka ukumpompa igazi (diastolic
BP) zaziphezulu ukusuka kwimizuzu engama-30 (p<0,001 kunye ne-p=0,015,
ngokulandelanayo), i-santya sokubetha kwentliziyo (HR) yehla kwimizuzu eli-10
(p=0,015), ngelixa uxinzelelo lokubetha kwentliziyo kunye ne-MAP zonyuka ukusuka
kwimizuzu engama-30 (p=0,043 kunye ne p<0,001).
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Ukusetyenziswa kwe-ED ngokuthelekiswa nento efaniswa neyeza kodwa elingelilo
esetyenziselwa ekukholiseni nje (placebo), unxinzelelo lwegazi (BP) lwaluphezulu
kuzo zonke indawo ukusuka kwisiseko (p<0,001), ngelixa isantya sokubetha
kwentliziyo (HR) kubonise ukunyuka okukhulu kwimizuzu engama-90 (p<0,001).
Uxinzelelo lokubetha kwentliziyo (Pulse) kunye ne-MAP zaziphezulu ekusebenziseni
iziselo ezinika amandla (ED), zabonakala kakhulu kwimizuzu engama-90 (p<0,001)
yoxinzelelo lokubetha kwentliziyo(pulse), kwaye kuzo zonke iindawo ze-MAP.
Uphononongo lufumanise ukuba uhlobo lwesiselo lunento oluyenzayo ebonakalayo
kuxinzelelo lwegazi (BP) (p<0,001) kwaye lwabonisa okuyinxalenye kwisantya
sokubetha kwentliziyo (HR) (p=0,052). Ukusebenzisana phakathi kohlobo lwesiselo
kunye neendawo zexesha kunefuthe olubonakalayo kuxinzelelo lwegazi xa intliziyo
liqala ukumpompa igazi (systolic) (p<0,001) kunye ne-MAP (p<0,001), kunye
nokuyinxalenye kuxinzelelo lwegazi xa iyekile ukumpompa igazi (diastolic) (p=0,057).
Isiphelo: I-EDs (Iziselo ezinika Amandla) zinyuse kakhulu unxinzelelo lwegazi (BP)
kwixesha elimalunga neyure ezi-2 kuthelekiswa nento efaniswa neyeza kodwa
elingelilo esetyenziselwa ekukholiseni nje (placebo). Nangona isantya sokubetha
kwentlinziyo (HR) sisehla, amaxabiso ayephezulu kwiziselo ezinika amandla (ED)
ngokumalunga nento efaniswa neyeza kodwa elingelilo esetyenziselwa ekukholiseni
nje (placebo). Olu qwalaselo lunokuthi lubalelwe kwizenzo zesivuseleli i-vaso kunye
nechiza ukuvelisa iziphumo zokusebenza kophawu lwenkqubo yemithambo-luvo
enovelwano ngokukhuthaza ukuvuselela imizwa yovelwano. yomthamo we-bioactive
kwiziselo ezinika Amandla (EDs), ngakumbi ngenxa yokuhambelana phakathi kwe khafini (caffeine) kunye nezinto ezimuncu ezisetyenziselwa ukunika amandla
kwiziselo i-taurine; Energy drink; Isiselo esinika amandla
2023-01-01T00:00:00Z