Ugandan medicinal plants used traditonally for oral care : investigation of extracts for anti-bacterial, cytotoxic and anti-inflammatory effects

The use of traditional medicine for treating human diseases remain widespread in low-resource settings. Medicinal plants form the backbone for traditional medicine systems in many parts of the world. In Uganda, most communities rely on medicinal plants to prevent and treat oral diseases. Despite the long history and widespread use of these plants in oral health care, there is limited scientific evidence on the efficacy and safety of these plants. The aim of this thesis was to investigate various extracts from the medicinal plants for anti-bacterial, cytotoxic and potential anti-inflammatory effects. The thesis is based on three studies. Study 1 investigated 16 commonly used plant species from different parts of Uganda. Pulp juice from fresh plant materials and solvent extracts (hexane, methanol and water) from dry plant materials were obtained and tested for their anti-bacterial effects on periodontopathic bacteria Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia and cariogenic bacteria Streptococcus mutans, Streptococcus sobrinus, Lactobacillus acidophilus. Study II assessed the essential oil extracts from ten Ugandan aromatic medicinal plants for growth inhibitory effects on periodontopathic bacteria A. actinomycetemcomitans, P. gingivalis, and cariogenic bacteria S. mutans and L. acidophilus. Chemical compositions of the oils were explored by gas chromatography–mass spectrometry. Study III investigated the cytotoxicity of essential oils from four promising plants (Bidens pilosa, Ocimum gratissimum, Cymbopogon nardus, Zanthoxylum chalybeum) that had shown strong anti-bacterial effects on Gram-negative periodontopathic bacteria A. actinomycetemcomitans, P. gingivalis in Study II. Potential effects of the oils on the production of pro-inflammatory cytokines (IL-6, IL-8 and prostaglandin E2) by human gingival fibroblasts induced by IL-1β were also investigated. In study I, the major findings were that fresh pulp juice prepared from Zanthoxylum chalybeum and Euclea latidens showed activity against all the bacterial species tested and at all strengths. Hexane extract from the aerial part of Helichrysum odoratissimum exhibited the best activity with MIC ranging from 0.0125 to 0.5mg/ml on all the bacterial species tested except A. actinomycetemcomitans. Methanol extract from Lantana trifolia was active on all the bacteria tested with MIC ranging 0.25 to 1mg/ml. In study II, the major findings were that essential oil from Cymbopogon nardus exhibited the highest activity with complete growth inhibition of A. actinomycetemcomitans, P. gingivalis at all the three concentrations tested, the major constituents in the oil being mainly oxygenated sesquiterpenes. Essential oils extracted from Teclea nobilis. Hoslundia opposita, Ocimum gratissimum and Bidens pilosa were also considered promising because they showed marked growth inhibitory effects on least 2 bacterial species. In study III, essential oil from Z. chalybeum was the most cytotoxic while the oil from C. nardus the least cytotoxic. Essential oil from O. gratissimum significantly decreased baseline and induced secretion of Prostaglandin E2. We conclude that fresh extracts from the roots of Z. chalybeum and E. latidens had anti-bacterial effects on the cariogenic and periodontopathic bacteria, confirming the use of chewing sticks prepared from these plants as a tool for brushing teeth. The hexane extract from the aerial part of H. odoratissimum had strong anti-bacterial effects on cariogenic and periodontopathic bacteria, suggesting the potential use of this extract, or isolated active principles, in the treatment or prevention of dental caries and periodontal diseases. The marked inhibitory effects of the essential oils on periodontopathic bacteria A. actinomycetemcomitans and P. gingivalis suggest these oils could be avenues to explore for possible application in treatment of periodontal diseases. The essential oil extracted from O. gratissimum demonstrated both anti-bacterial and anti-inflammatory effects suggesting the oil could be worth exploring for possible application in treatment of periodontitis

Teachers’ Perception on Implementing the Revised Lower Secondary Curriculum in Selected Schools in Uganda: A Focus on Emerging Issues and Coping Strategies

This study explored teachers’ perception on the implementation of Comptency-based Curriculum (CBC) in lower secondary schools in Uganda that was rolled out in 2020. The shift from the Knowledge-Based Curriculum (KBC) to CBC caused a cultural shock to those who had been nurtured in a purely teacher-centred curriculum! Teachers got challenged over their authority and autonomy in the delivery of instruction. Discussion was centred on teachers’ readiness to implement; pedagogical competences to plan, facilitate and assess CBC. In this phenomenological study, data was collected from 12 randomly selected secondary schools in urban, semi-urban and rural areas of Uganda. The population comprised teachers of Lower Secondary, Directors of Studies and Headteachers. Data was analyzed qualitatively through codes and themes and reported thematically, backed with verbatim quotations and statements from participants. Majority of the teachers were struggling with gaps in planning and content delivery, CBC stimulated hands-on-learning, teachers’ preparedness was considerably low due to lack of prior training, ICT integration was still an uphill task, majority of teachers were still stuck to traditional methodologies. CBC is too demanding and ambitious! NCDC should, therefore, design retooling packages for continuous capacity building, schools should promote peer mentorship, collaboration and Network initiatives

Factors influencing adherence to antiretroviral therapy among people living with HIV in an urban and rural setting, Tanzania

Adherence is one of the most crucial determinants of treatment response to antiretroviral therapy (ART). An analytical cross-sectional study was conducted in 24 Care and Treatment Centres (CTC) in Dar es Salaam and Iringa regions in Tanzania. Data was collected using questionnaire and appointments records. A total of 943 patients attending at the care and treatment sites in Dar es Salaam and Iringa were recruited. Adherence based on keeping appointments and on four days recall was 65% and 70%, respectively. Adherence based on taking ART more than 95% of the time in one month was 83%. Satisfaction with health services, having treatment support, having knowledge on the use of ART, early presentation to CTC, and being on ART for more than one year, were associated with good adherence. Being in the urban region, using traditional medicine, medicine side effects and alcohol consumption problems negatively associated with adherence to ART.Keywords: Adherence barriers, antiretroviral therapy, HIV, Tanzania, rural, urba

Risk factors of visceral leishmaniasis in East Africa: a case-control study in Pokot territory of Kenya and Uganda

BACKGROUND: In East Africa, visceral leishmaniasis (VL) is endemic in parts of Sudan, Ethiopia, Somalia, Kenya and Uganda. It is caused by Leishmania donovani and transmitted by the sandfly vector Phlebotomus martini. In the Pokot focus, reaching from western Kenya into eastern Uganda, formulation of a prevention strategy has been hindered by the lack of knowledge on VL risk factors as well as by lack of support from health sector donors. The present study was conducted to establish the necessary evidence-base and to stimulate interest in supporting the control of this neglected tropical disease in Uganda and Kenya. METHODS: A case-control study was carried out from June to December 2006. Cases were recruited at Amudat hospital, Nakapiripirit district, Uganda, after clinical and parasitological confirmation of symptomatic VL infection. Controls were individuals that tested negative using a rK39 antigen-based dipstick, which were recruited at random from the same communities as the cases. Data were analysed using conditional logistic regression. RESULTS: Ninety-three cases and 226 controls were recruited into the study. Multivariate analysis identified low socio-economic status and treating livestock with insecticide as risk factors for VL. Sleeping near animals, owning a mosquito net and knowing about VL symptoms were associated with a reduced risk of VL. CONCLUSIONS: VL affects the poorest of the poor of the Pokot tribe. Distribution of insecticide-treated mosquito nets combined with dissemination of culturally appropriate behaviour-change education is likely to be an effective prevention strategy

To err is human, to correct is public health: a systematic review examining poor quality testing and misdiagnosis of HIV status.

INTRODUCTION: In accordance with global testing and treatment targets, many countries are seeking ways to reach the "90-90-90" goals, starting with diagnosing 90% of all people with HIV. Quality HIV testing services are needed to enable people with HIV to be diagnosed and linked to treatment as early as possible. It is essential that opportunities to reach people with undiagnosed HIV are not missed, diagnoses are correct and HIV-negative individuals are not inadvertently initiated on life-long treatment. We conducted this systematic review to assess the magnitude of misdiagnosis and to describe poor HIV testing practices using rapid diagnostic tests. METHODS: We systematically searched peer-reviewed articles, abstracts and grey literature published from 1 January 1990 to 19 April 2017. Studies were included if they used at least two rapid diagnostic tests and reported on HIV misdiagnosis, factors related to potential misdiagnosis or described quality issues and errors related to HIV testing. RESULTS: Sixty-four studies were included in this review. A small proportion of false positive (median 3.1%, interquartile range (IQR): 0.4-5.2%) and false negative (median: 0.4%, IQR: 0-3.9%) diagnoses were identified. Suboptimal testing strategies were the most common factor in studies reporting misdiagnoses, particularly false positive diagnoses due to using a "tiebreaker" test to resolve discrepant test results. A substantial proportion of false negative diagnoses were related to retesting among people on antiretroviral therapy. Conclusions HIV testing errors and poor practices, particularly those resulting in false positive or false negative diagnoses, do occur but are preventable. Efforts to accelerate HIV diagnosis and linkage to treatment should be complemented by efforts to improve the quality of HIV testing services and strengthen the quality management systems, particularly the use of validated testing algorithms and strategies, retesting people diagnosed with HIV before initiating treatment and providing clear messages to people with HIV on treatment on the risk of a "false negative" test result

Enhancing quality of student teachers’ practices through reflective journal writing during school practice

This paper explores the role of journal writing in enhancing student teachers’ learning during school practice. It analyses data from 22 student teachers’ journals and 23 questionnaires. The study focuses on the areas that student teachers reflected on most, the nature of their reflection and the extent to which previous experiences informed their subsequent reflection and learning. Findings showed that student teachers frequently reflected on handling indiscipline issues, procedures and outcomes of supervision, but less on their own learning. Inadequate reflection on their learning suggests that journal writing has not yet sufficiently promoted student teachers’ professional growth. Generally, the examination and cultural orientation in the Ugandan society influence student teachers’ journal writing. Finally, the paper proposes strategies for improving journal writing in order to enhance the potential of students learning from reflection during school practice

Enhancing quality of student teachers’ practices through reflective journal writing during school practice

This paper explores the role of journal writing in enhancing student teachers’ learning during school practice. It analyses data from 22 student teachers’ journals and 23 questionnaires. The study focuses on the areas that student teachers reflected on most, the nature of their reflection and the extent to which previous experiences informed their subsequent reflection and learning. Findings showed that student teachers frequently reflected on handling indiscipline issues, procedures and outcomes of supervision, but less on their own learning. Inadequate reflection on their learning suggests that journal writing has not yet sufficiently promoted student teachers’ professional growth. Generally, the examination and cultural orientation in the Ugandan society influence student teachers’ journal writing. Finally, the paper proposes strategies for improving journal writing in order to enhance the potential of students learning from reflection during school practice

Characterization of an Electroless Plated Silver/Cysteine Sensor Platform for the Electrochemical Determination of Aflatoxin B 1

An electroless plated silver/cysteine sensor platform [Glass|silver|cysteine|aflatoxin B 1 |horseradish peroxidase] for the Electrochemical detection of aflatoxin B 1 was developed and characterized. This involved four major steps: (1) an electroless deposition of silver (plating) onto a glass slide, (2) immobilization of cysteine; (3) conjugation of aflatoxin B 1 to cysteine groups; and (4) blocking of free cysteine groups with horseradish peroxidase (HRP). The binding of cysteine to the silver was demonstrated by the disappearance of thiol (S-H) groups at 2500 cm −1 using Fourier transmittance infrared spectra (FT-IR), while the subsequent steps in the assembly of sensor platform were monitored using both FT-IR and cyclic voltammetry, respectively. The sensor platform exhibited a broadened nonsymmetrical redox couple as indicated by cyclic voltammetry. The platform was further characterized for sensitivity and limit of detection. The indirect competitive immunoassay format, whereby free and immobilized aflatoxin B 1 on the sensor competed for the binding site of free anti-aflatoxin B 1 antibody, was used at various concentrations of aflatoxin B 1 . The sensor generated differential staircase voltammogram that was inversely proportional to the concentration of aflatoxin B 1 and aflatoxin B 1 in the range of 0.06-1.1 ng/mL with a detection limit of 0.08 ng/mL could be detected