The composition and antimicrobial activity of leaf essential oils of selected agathosma species ( rutaceae )

A research report submitted to the faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Medicine ( Pharmaceutical Affairs )This project was conducted to investigate properties and to record the essential oil profiles of a selection of species belonging to the genus agasthosma. Plants have been used for many years by the local South African to treat various infections and illnesses. This knowledge has largely been untapped. Buchu is one of the plant species that are used extensively by the San and Khoi people. It is remarkable that of the ca. 150 agathosma species indigenous to South Africa only two species ( Agasthosma crenulata and agathosma betulina ) have been investigated for biological activity. The genus Agasthosma is traditionally used for the following conditions ; stomach ailments, fever, coughs, cold, flu, urinary tract, and kidney infections, haematuria, prostatitis, rheumatism, gout, bruises and for antiseptic purposes.IT201

The role of Serum Amyloid A in NLRP3 inflammasome signalling in breast and colon cancer

Thesis (PhD)--Stellenbosch University, 2022.ENGLISH ABSTRACT: Introduction: Cancer is a complex disease with multiple interactions targeting the organism on cellular, tissue and systemic levels. The main research focus for the past decades has been on the genome and on the molecular level where signaling pathways were dissected for the development of targeted therapies. However, in order to develop more efficient therapeutic regimes, a better understanding on systemic level is required. Over the past few years, the role of serum amyloid A (SAA) has gathered significant evidence which highlights its role in the pathogenesis of several cancers, including breast and colorectum carcinomas. To date, SAA has been shown to bind to several pattern recognition receptors, which might suggest that inflammasomes play a role in the tumour-promoting properties of SAA. Inflammasomes are cytoplasmic multiprotein complexes characterized by a sensor protein, an adaptor protein, and inflammatory caspases. However, the role of inflammasomes in cancer remain controversial. The aim of this study was therefore to investigate the role of SAA in inflammasome signaling in breast and colon cancer. Methods: In this 3-part animal study, tissues were subjected to immunoblotting, real-time PCR, haematoxylin and eosin staining and immunohistochemistry. For the first inflammatory model, wild-type and SAA double knockout C57BL/6 mice received 2.5% dextran sulfate sodium, which was administered for a total of 5 days. To assess tumourigenesis, colitis-associated cancer and triple negative breast cancer models were used, respectively. For colitis- associated cancer, wild-type and SAA double knockout C57BL/6 mice received an intraperitoneal injection of 12.5 mg/kg azoxymethane. After one week, dextran sulfate sodium treatment was administered at a concentration of 2.5% for a total of 5 days, followed by a recovery period of 16 days. Dextran sulfate sodium treatment was administered for a total of 3 cycles. Triple negative breast tumours were established in wild-type and SAA double knockout C57BL/6 mice by injecting EO771 cells subcutaneously at the fourth mammary fat pad. The experimental endpoint was reached when tumour volumes reached 300-400 mm3. Results: In this study we have showed that in an in vivo model of dextran sulfate sodium induced colitis, SAA ablation exerted pro-inflammatory properties independent of the NLRP3 inflammasome. The ablation of serum amyloid A1/2 was associated with the increased expression of pro- inflammatory cytokines. In contrast, in an in vivo colitis-associated cancer and in a triple negative breast cancer model, the ablation of SAA suppressed canonical NLRP3 inflammasome activation, which was associated with anti-inflammatory properties. These findings suggest that during tumourigenesis, SAA functions as an endogenous damage associated molecular pattern in the tumour microenvironment. Conclusion: Here we show for the first time, in models of CAC and TNBC, the novel role of SAA in the activation of the NLRP3 inflammasome and the generation of pro-inflammatory cytokines, two mechanisms known to promote tumour development and metastasis. This study emphasizes the notion that the tumour-induced systemic environment acts as a critical regulator of cancer progression and metastasis. In conclusion, simultaneously targeting SAA and NLRP3 components could be beneficial for cancer treatments.AFRIKAANSE OPSOMMING: Inleiding: Kanker is 'n komplekse siekte met verskeie interaksies wat die organisme op sellulêre, weefsel- en sistemiese vlakke teiken. Die hoof navorsingsdoel vir die afgelope dekades was op die genoom sowel as seinoordragpaaie op molekulêre vlak te dissekteer vir die ontwikkeling van geteikende terapieë. Om meer doeltreffende terapeutiese prosedures te ontwikkel, is 'n beter begrip op sistemiese vlak egter nodig. Oor die afgelope paar jaar het die rol van serum amiloïed A (SAA), 'n akuut-fase proteïen, hoofsaaklik deur hepatosiete geproduseer, beduidende bewyse gelewer vir die rol daarvan in die patogenese van verskeie kankers, insluitend bors- en kolorektumkarsinome. Dit is al bewys dat SAA aan verskeie reseptore bind, soos TLRs, wat voorstel dat inflammasome 'n rol speel in tumorgenese. Inflammasome is sitoplasmiese multiproteïen-komplekse wat gekenmerk word deur 'n sensorproteïen, 'n adapterproteïen en inflammatoriese kaspases. Die rol van inflammasome in kanker bly egter omstrede. Die doel van hierdie studie was dus om die rol van SAA in inflammasoom aktivering in bors- en kolonkanker te ondersoek. Metodes: In hierdie 3-delige dierestudie is weefsels ondersoek deur gebruik te maak van qPCR, hematoksilien- en eosienkleuring en immunohistochemie. Vir die eerste inflammatoriese model het wilde-tipe (WT) asook muise wat nie SAA gene besit nie (SAADKO), 2.5% dekstraansulfaatnatrium (DSS) ontvang, wat vir 'n totaal van 5 dae toegedien is. Om tumorgenese te ondersoek, is kolitis-geassosieerde kanker- (CAC) en trippel negatiewe borskankermodelle (TNBC) onderskeidelik gebruik. Vir CAC het wilde-tipe en SAADKO C57BL/6 muise 'n intraperitoneale inspuiting van 12.5 mg/kg asoksimetaan ontvang. Na een week is DSS-behandeling toegedien in geoutoklaveerde drinkwater teen 'n konsentrasie van 2.5 % vir 'n totaal van 5 dae, gevolg deur 'n herstelperiode van 16 dae. DSS-behandeling is vir 'n totaal van 3 siklusse toegedien. TNBC gewasse is gevestig in WT en SAADKO C57BL/6 muise deur EO771 selle onderhuids in die vetweefsel van die vierde melkklier in te spuit. Die eksperimentele eindpunt is bereik toe tumorvolumes 300-400 mm3 bereik het. Resultate: In hierdie studie het ons getoon dat in 'n in vivo model van dekstraansulfaat natrium- geïnduseerde kolitis, SAA ablasie pro-inflammatoriese eienskappe uitgeoefen het onafhanklik van die NLRP3 inflammasoom. Die ablasie van SAA1/2 was geassosieer met die verhoogde uitdrukking van pro-inflammatoriese sitokiene. In teenstelling hiermee, in 'n in vivo kolitis- geassosieerde kanker en in 'n trippel negatiewe borskankermodel, het die ablasie van SAA kanonieke NLRP3-inflammasoomaktivering onderdruk, wat geassosieer was met anti- inflammatoriese eienskappe. Hierdie bevindinge dui daarop dat SAA as 'n endogene skade- geassosieerde molekulêre patroon in die tumor mikro-omgewing tydens tumorgenese, funksioneer. Gevolgtrekking: Hier wys ons vir die eerste keer, in modelle van CAC en TNBC, die nuwe rol van SAA in die aktivering van die NLRP-inflammasoom en die generering van pro-inflammatoriese sitokiene, twee meganismes wat bekend is om tumorontwikkeling en metastase te bevorder. Hierdie studie beklemtoon die idee dat die tumor-geïnduseerde sistemiese omgewing optree as 'n belangrike reguleerder van kankerprogressie en metastase. Ten slotte, deur gelyktydig SAA en NLRP3-komponente te teiken deur reseptore te inhibeer of deur stroomafwaartse seinoordrag meganismes te voorkom, kan dit voordelig wees vir kankerbehandelings.Doctora

Associations between plasma tenofovir concentration and renal function markers in HIV-infected women

Background: Tenofovir disoproxil fumarate (TDF) has been associated with kidney tubular dysfunction and reduced renal function. Limited studies were performed in Europe and Asia that related plasma tenofovir (TFV) concentration with renal function; no such studies to date have been performed on Africans.Objective: To investigate the correlation between plasma tenofovir (TFV)  concentration and certain renal function markers in HIV-infected women on TDF antiretroviral therapy (ART). These markers were also compared to a HIV-uninfected control group.Methods: HIV-infected women (n = 30) on TDF-based ART were matched with 30 controls for age and body mass index. Renal markers analysed were estimated glomerular filtration rate (eGFR), creatinine clearance (CrCl), serum creatinine, albuminuria, glucosuria, serum urea, serum uric acid, urine sodium and maximum tubular reabsorption of phosphate. Baseline eGFR and CrCl data were obtained retrospectively for the HIV-infected women. Plasma TFV was assayed using a validated HPLC-MS/MS method. Stepwise regression, Mann–Whitney test, unpaired and paired t-tests were applied in the statistical analyses.Results: TFV concentration was independently associated with albuminuria (adjusted r2 = 0.339; p = 0.001) in HIV-infected women. In the adjusted (weight) analysis, eGFR (p = 0.038), CrCl (p = 0.032) and albuminuria (p = 0.048) were significantly higher in HIV-infected compared to the uninfected women, but eGFR was abnormally high in HIV-infected women. Both eGFR (p < 0.001) and CrCl (p = 0.008) increased from baseline to follow-up in HIV-infected women.Conclusion: Plasma TFV concentration was associated with increased albuminuria in HIVinfected women in this sub-study. Both eGFR and CrCl were increased in HIV-infected women from baseline. These findings should be confirmed in larger studies, and hyperfiltration in HIV-infected women warrants further investigation

Clinical and demographic factors associated with sexual behaviour in children with autism spectrum disorders

INTRODUCTION : The sexual behaviour and development of children with autism spectrum disorders (ASDs) have been mostly overlooked in research and practice. This study aimed to determine the association between certain clinical and demographic factors found in a sample of children with ASDs, and their reported sexual behaviour (RSB). METHODS : The study was conducted at a school in Gauteng, South Africa, for learners with ASDs. Two questionnaires completed by caregivers/parents enquired about family stability, clinical profile and RSB (if any) in their child. RSB was analysed via three domains: self-care, socio-sexual skills and actual RSB, with additional information from school records. RESULTS : Of the 107 questionnaires distributed, only 31 parents responded and 24 agreed to participate. The 24 (100%) children included 10 pubertal and 14 pre-pubertal children, of which 18 (n = 18) had more stable primary caregiver statuses as well as more stable socioeconomic and family environments. Two of the 14 pre-pubertal children had abnormal self-care, whereas none of the 10 pubertal children had any abnormal self-care. Eight of the 18 children from more stable environments displayed abnormal sexual behaviours. Of the 6 children from less stable environments, two displayed more abnormal socio-sexual skills, whereas 9 of the 18 children from more stable environments displayed more abnormal sexual behaviour. In contrast with the postulated hypothesis that children from less stable socioeconomic and family environments would exhibit more abnormal sexual behaviours, this study did not find any evidence of such a relationship or association. CONCLUSION : ASDs are characterised by deficits in communication and social skills. These may lead to an affected individual struggling to develop appropriate sexual behaviour. If specific risk factors that contribute to the development of abnormal sexual behaviour can be identified, one can try to modify/prevent these where some degree of prevention or alleviation may be possible.http://www.sajpsychiatry.orgam2017Psychiatr

The metabolic syndrome and renal function in an African cohort infected with human immunodeficiency virus

Introduction: The human immunodeficiency virus (HIV) is often accompanied by renal dysfunction. It is expected that metabolic syndrome (MetS) may exacerbate renal impairment.Objective: We therefore determined the prevalence of MetS and the association thereof with renal function in a South African cohort infected with HIV.Methods: We matched 114 HIV-infected (77.3% on antiretroviral therapy [ART] and 22.7% ART-naïve) and 114 HIV-uninfected individuals according to age, sex and locality. We examined cardiovascular, anthropometric and metabolic measurements and determined the MetS. Renal function was assessed using standardised procedures.Results: The prevalence of MetS was lower in the HIV-infected individuals as compared to the uninfected individuals (28% vs. 44%, p = 0.013). The HIV-infected group presented with a lower body mass index (BMI) and waist circumference (WC) (all p < 0.001), as well as blood pressure (BP) ( p ≤ 0.0021). The results were confirmed when comparing the HIV-infected group using ART (N = 85) and the HIV-uninfected group. When comparing the HIV-infected individuals with MetS to the HIV-uninfected individuals with MetS, no differences in BP were seen. With regard to renal function, the HIV-infected individuals with MetS (n = 32) had 43% higher urinary albumin-creatinine ratio (uACR) compared to the HIV-uninfected individuals with MetS, after adjusting for age, sex and WC (p = 0.032). None of the other renal function markers differed after adjustments for WC or BMI.Conclusion: The HIV-infected Africans with MetS had almost twofold higher uACR, despite the low prevalence of MetS, compared to their uninfected counterparts. The combination of HIV and MetS seemed to increase the risk for renal impairment

The metabolic syndrome and renal function in an African cohort infected with human immunodeficiency virus

Introduction: The human immunodeficiency virus (HIV) is often accompanied by renal dysfunction. It is expected that metabolic syndrome (MetS) may exacerbate renal impairment. Objective: We therefore determined the prevalence of MetS and the association thereof with renal function in a South African cohort infected with HIV. Methods: We matched 114 HIV-infected (77.3% on antiretroviral therapy [ART] and 22.7% ART-naïve) and 114 HIV-uninfected individuals according to age, sex and locality. We examined cardiovascular, anthropometric and metabolic measurements and determined the MetS. Renal function was assessed using standardised procedures. Results: The prevalence of MetS was lower in the HIV-infected individuals as compared to the uninfected individuals (28% vs. 44%, p = 0.013). The HIV-infected group presented with a lower body mass index (BMI) and waist circumference (WC) (all p < 0.001), as well as blood pressure (BP) (p ≤ 0.0021). The results were confirmed when comparing the HIV-infected group using ART (N = 85) and the HIV-uninfected group. When comparing the HIV-infected individuals with MetS to the HIV-uninfected individuals with MetS, no differences in BP were seen. With regard to renal function, the HIV-infected individuals with MetS (n = 32) had 43% higher urinary albumin-creatinine ratio (uACR) compared to the HIV-uninfected individuals with MetS, after adjusting for age, sex and WC (p = 0.032). None of the other renal function markers differed after adjustments for WC or BMI. Conclusion: The HIV-infected Africans with MetS had almost twofold higher uACR, despite the low prevalence of MetS, compared to their uninfected counterparts. The combination of HIV and MetS seemed to increase the risk for renal impairment

Clinical and demographic factors associated with sexual behaviour in children with autism spectrum disorders

INTRODUCTION : The sexual behaviour and development of children with autism spectrum disorders (ASDs) have been mostly overlooked in research and practice. This study aimed to determine the association between certain clinical and demographic factors found in a sample of children with ASDs, and their reported sexual behaviour (RSB). METHODS : The study was conducted at a school in Gauteng, South Africa, for learners with ASDs. Two questionnaires completed by caregivers/parents enquired about family stability, clinical profile and RSB (if any) in their child. RSB was analysed via three domains: self-care, socio-sexual skills and actual RSB, with additional information from school records. RESULTS : Of the 107 questionnaires distributed, only 31 parents responded and 24 agreed to participate. The 24 (100%) children included 10 pubertal and 14 pre-pubertal children, of which 18 (n = 18) had more stable primary caregiver statuses as well as more stable socioeconomic and family environments. Two of the 14 pre-pubertal children had abnormal self-care, whereas none of the 10 pubertal children had any abnormal self-care. Eight of the 18 children from more stable environments displayed abnormal sexual behaviours. Of the 6 children from less stable environments, two displayed more abnormal socio-sexual skills, whereas 9 of the 18 children from more stable environments displayed more abnormal sexual behaviour. In contrast with the postulated hypothesis that children from less stable socioeconomic and family environments would exhibit more abnormal sexual behaviours, this study did not find any evidence of such a relationship or association. CONCLUSION : ASDs are characterised by deficits in communication and social skills. These may lead to an affected individual struggling to develop appropriate sexual behaviour. If specific risk factors that contribute to the development of abnormal sexual behaviour can be identified, one can try to modify/prevent these where some degree of prevention or alleviation may be possible.http://www.sajpsychiatry.orgam2017Psychiatr

The paracrine effects of fibroblasts on Doxorubicin-treated breast cancer cells

CITATION: Carla, F., et al. 2019. The paracrine effects of fibroblasts on Doxorubicin-treated breast cancer cells. Experimental Cell Research, 381(2):280-287. doi:10.1016/j.yexcr.2019.05.020The original publication is available at https://www.sciencedirect.com/journal/experimental-cell-researchThe Doctoral/Master’s degree for this article is available at [http://hdl.handle.net/10019.1/106181]Breast cancer is frequently diagnosed in women and poses a major health problem throughout the world. Currently, the unresponsiveness of cancer cells to chemotherapeutics is a major concern. During chemotherapeutic treatment with Doxorubicin, neighbouring cells in the tumor microenvironment are also damaged. Depending on the concentration of Doxorubicin, apoptotic or senescent fibroblasts in the tumor microenvironment can then secrete a variety of bioactive molecules which promote tumor growth, metastasis and drug resistance. Mouse embryonic fibroblasts (MEFs) were treated with Doxorubicin to induce apoptosis and senescence respectively. Conditioned media was collected from the MEFs and was used to assess the paracrine effects between fibroblasts and E0771 murine breast cancer cells. Senescent fibroblasts significantly increased cell viability in E0771 cells following Doxorubicin treatment by activating Akt and ERK. Autophagy contributed to cancer cell death and not to treatment resistance in breast cancer cells. Our results highlight the complexity of the tumor microenvironment where chemotherapeutic agents such as Doxorubicin can induce significant changes fibroblasts which can affect tumor growth via the secretion of paracrine factors. Here we have demonstrated that those secreted paracrine factors enhance breast cancer growth and induce therapeutic resistance through the evasion of apoptotic cell death.https://www.sciencedirect.com/science/article/pii/S0014482719302617?via%3DihubPublisher's versio

The use of confocal microscopy in quantifying changes in membrane potential

Monitoring the plasma membrane potential and its changes can be a time consuming and challenging task especially when conventional electrophysiological techniques are used. The use of potentiometric fluorophores, namely tetramethylrhodamine methylester (TMRM), and digital imaging devices (laser scanning confocal microscopy) provides reliable and time efficient method. Two scorpion pore-forming peptides, namely PP and OP1, were used as a tool to induce depolarization of the plasma membrane potential of neuroblastoma cell line and cardiac myocytes. Alternative methods for the neuroblastoma cells and cardiac myocytes were used. Depolarization of the neuroblastoma cells was calibrated with 140 mM KCl solution with 1 µM valinomycin, after which intensity readers were substituted in the Nernst equation for quantification. Calibration of the alternative method used of the cardiac myocytes&apos; plasma membrane potential changes was calibrated with the use of 5, 20, 40, and 80 mM KCl solutions with 1 µM valinomycin. A calibration curve was then constructed from which plasma membrane potential could be calculated

Serum amyloid A and inflammasome activation : a link to breast cancer progression?

CITATION: Fourie, C. et al. 2021.Serum amyloid A and inflammasome activation: A link to breast cancer progression? Cytokine & Growth Factor Reviews, 59:62-70. doi:10.1016/j.cytogfr.2020.10.006The original publication is available at https://www.sciencedirect.com/journal/cytokine-and-growth-factor-reviewsBreast cancer is the most frequently diagnosed cancer in women globally. Although there have been many significant advances made in the diagnosis and treatment of breast cancer, numerous unresolved challenges remain, which include prevention, early diagnosis, metastasis and recurrence. The role of inflammation in cancer development is well established and is believed to be one of the leading hallmarks of cancer progression. Recently, the role of the inflammasome, a cytosolic multiprotein complex, has received attention in different cancers. By contributing to the activation of inflammatory cytokines the inflammasome intensifies the inflammatory cascade. The inflammasome can be activated through several pathways, which include the binding of pattern associated molecular patterns (PAMPs) and damage associated molecular patterns (DAMPs) to toll-like receptors (TLRs). Serum amyloid A (SAA), a non-specific acute-phase protein, can function as an endogenous DAMP by binding to pattern recognition receptors like TLRs on both breast cancer cells and cancer associated fibroblasts (CAFs). SAA can thus stimulate the production of IL-1β, thereby creating a favourable inflammatory environment to support tumour growth. The aim of this review is to highlight the possible role of SAA as an endogenous DAMP in the tumour microenvironment (TME) thereby promoting breast cancer growth through the activation of the NLRP3 inflammasome.https://www.sciencedirect.com/science/article/pii/S1359610120302203?via%3DihubPublishers versio