Mechanisms of action of traditional herbal medicines used in the management of diabetes mellitus: a review of the literature

Background: The prevalence of diabetes mellitus is increasing rapidly in both developed and developing countries. There are various conventional medicines used for the management of the disease, but there is also increased interest in the use of traditional herbal medicines. Although the concepts of illness and diseases in traditional medicine may differ from conventional medicine the outcomes are similar. The antihyperglycemic effects of various herbal medicines prescribed by traditional healers in the management of diabetes mellitus have been proven scientifically using several in-vitro and in-vivo models as well as clinical studies in humans.Materials and methods: Literature search was done in several databases. Firstly, the search was conducted using the key terms: diabetes mellitus and traditional medicine, diabetes mellitus and herbs, diabetes mellitus and plants, traditional concepts of health and sickness and diabetes mellitus. After identifying the herbs or plants used in diabetes a search was then conducted by name of herb and efficacy in management of diabetes mellitus.Results: This review highlights the similarities and differences in mechanisms of action of various traditional herbal medicines and conventional medicines. The major observation is that, herbal medicines often have multiple mechanisms of action ideally making them combination therapies. The review further highlights the need to develop an algorithm of a minimum battery of in-vitro and animal studies that can provide solid evidence of the potential of traditional medicines as anti-diabetic treatments.Conclusion: Traditional herbal medicines often have multiple phytoconstituents and hence multiple mechanisms of action ideally making them combination therapies.Keywords: traditional herbal medicines, diabetes mellitus, mechanisms of actio

MECHANISMS OF ACTION OF TRADITIONAL HERBAL MEDICINES USED IN THE MANAGEMENT OF DIABETES MELLITUS: A REVIEW OF THE LITERATURE

Background: The prevalence of diabetes mellitus is increasing rapidly in both developed and developing countries. There are various conventional medicines used for the management of the disease, but there is also increased interest in the use of traditional herbal medicines. Although the concepts of illness and diseases in traditional medicine may differ from conventional medicine the outcomes are similar. The antihyperglycemic effects of various herbal medicines prescribed by traditional healers in the management of diabetes mellitus have been proven scientifically using several in-vitro and in-vivo models as well as clinical studies in humans. Materials and methods: Literature search was done in several databases. Firstly, the search was conducted using the key terms: diabetes mellitus and traditional medicine, diabetes mellitus and herbs, diabetes mellitus and plants, traditional concepts of health and sickness and diabetes mellitus. After identifying the herbs or plants used in diabetes a search was then conducted by name of herb and efficacy in management of diabetes mellitus. Results: This review highlights the similarities and differences in mechanisms of action of various traditional herbal medicines and conventional medicines. The major observation is that, herbal medicines often have multiple mechanisms of action ideally making them combination therapies. The review further highlights the need to develop an algorithm of a minimum battery of in-vitro and animal studies that can provide solid evidence of the potential of traditional medicines as anti-diabetic treatments. Conclusion: Traditional herbal medicines often have multiple phytoconstituents and hence multiple mechanisms of action ideally making them combination therapies

Phytochemical profile and in vitro antioxidant activity of Emelia M (EMB), Mshikazi and Delosma H herbal medicines as demonstrated in THP-1 and Jurkat leukaemia cell lines

Background: Three decoctions, namely Emelia M (EMB), Mshikazi and Delosma H are used by traditional health practitioners in KwaZulu-Natal, South Africa to treat and manage leukaemia and related conditionsObjectives: This study evaluated the in vitro antioxidant activity and phytochemical profile of the aqueous extracts of Emelia M (EMB), Mshikazi and Delosma H decoctions.Methods: Antioxidant activity of the extracts was evaluated using1-diphenyl-2-picrylhydrazyl (DPPH), glutathione (GSH), phosphomolybdate and thiobarbituric acid reactive substance (TBARS) assays. Phytochemical screening was used to determinethe presence of compounds.Results: The DPPH radical scavenging activity was similar to ascorbic acid for EMB and Delosma H, but not for Mshikazi. At 24 h, EMB increased GSH in both THP-1 and Jurkat cells similar to Delosma H while Mshikazi demonstrated the lowest activity. At 48 h, EMB and Delosma H revealed increased GSH in THP-1 cells with no significant decrease in GSH levels in Jurkat cells. However, EMB showed the lowest lipid peroxidation activity compared to Delosma H and Mshikazi after 24 h treatment of both cells. Phenols, flavonoids, terpenoids, saponins were present in all extracts.Conclusion: Extracts of the three decoctions possess both antioxidant and prooxidant properties through high scavenging activity and increased in lipid peroxidation. Keywords: Antioxidants; herbal medicines; Emelia M; Mshikazi; Delosma H

Annona stenophylla aqueous extract stimulate glucose uptake in established C2Cl2 muscle cell lines

Background: Annona stenophylla is a folk medicine popularly used in Zimbabwe for the treatment of many ailments. This study was carried out to determine some of the possible anti diabetic mechanisms of its action using in vitro cell culturing methods.Methods: A. stenophylla’s effects on glucose uptake were tested using muscle cells (C2Cl2). Expression of glucose 4 transporters was determined by treating cell lines with plant extract. Total RNA was isolated and using RT-PCR, GLUT 4 expression levels were quantified. Translocation of GLUT 4 was assessed using FITC fluorescence measured by flow cytometry.Results: Treatment of cells with plant extract significantly increased glucose uptake in a concentration dependent manner, with the highest concentration (250 μg/ml) giving 28% increased uptake compared to the negative control. The increase in glucose uptake (2.5 times more than control) was coupled to increase in GLUT 4 mRNA and subsequently GLUT 4 translocation. Wortmannin expunged the A. stenophylla induced increase in GLUT 4 mRNA and glucose uptake.Conclusion: The results suggest that A. stenophylla aqueous extract increases glucose uptake partly through increasing the GLUT 4 mRNA and translocation potentially acting via the PI-3-K pathway. This study confirms the ethnopharmacological uses of A.stenophylla indicating potential for anti-diabetic products formulation.Keywords: Annona stenophylla, glucose uptake, GLUT 4, diabetes, wortmannin

Prevalence and risk factors associated with retinopathy in diabetic patients at Parirenyatwa Hospital outpatients’ clinic in Harare, Zimbabwe

Diabetic retinopathy is the fifth leading cause of blindness worldwide accounting for nearly 5% of all blindness. However, most of the prevalence and incidence data is from developed countries, with very limited information from sub-Saharan Africa. The study sought to determine the prevalence of, and factors associated with, retinopathy in diabetic patients. Diabetes mellitus patients attending the outpatients’ clinic at Parirenyatwa Group of Hospitals between October 2013 and July 2014 were recruited into this analytical cross-sectional study. Demographic information was collected. A nurse carried out anthropometric measurements. An ophthalmologist using slit lamp indirect ophthalmoscopy with a 20-diopter and a 90-diopter lens diagnosed retinopathy. Blood samples were collected and analysed for triglycerides, total cholesterol, HDL cholesterol, glycosylated hemoglobin and serum creatinine. A total of 340 patients were enrolled into the study, of whom 73.2% were female. Mean (SD) age was 57.5 (14.9) years and there was no difference in age between females [57.6 (14.1) years] and males [57.2 (16.8) years]. The overall prevalence of diabetic retinopathy was 28.4%. Using multivariate logistic regression analysis retinopathy was associated with longerduration of diabetes mellitus (OR 1.06, 95% CI 1.03-1.09, p value ˂ 0.001) and lower serum creatinine (OR 0.99, 95% CI 0.97-1.00, p value 0.025). The prevalence of diabetic retinopathy was 28.4%. Longer duration of diabetes mellitus and lower serum creatinine, which is a marker of renal damage, were independent risk factors of diabetic retinopathy.Keywords: Diabetes mellitus; Diabetic retinopathy; Complications; Blindness; Prevalence; Risk facto

The University of Zimbabwe College of Health Sciences (UZ-CHS) BIRTH COHORT study: rationale, design and methods.

BACKGROUND Commencing lifelong antiretroviral therapy (ART) immediately following HIV diagnosis (Option B+), has greatly improved maternal-infant health. Thus, large and increasing numbers of HIV-infected women are on ART during pregnancy, a situation concurrently increasing numbers of HIV-exposed-uninfected (HEU) infants. Compared to their HIV-unexposed-uninfected (HUU) counterparts, HEU infants show higher rates of adverse birth outcomes, mortality, infectious/non-communicable diseases including impaired growth and neurocognitive development. There is an urgent need to understand the impact of HIV and early life ART exposures, immune-metabolic dysregulation, comorbidities and environmental confounders on adverse paediatric outcomes. METHODS Six hundred (600) HIV-infected and 600 HIV-uninfected pregnant women ≥20 weeks of gestation will be enrolled from four primary health centres in high density residential areas of Harare. Participants will be followed up as mother-infant-pairs at delivery, week(s) 1, 6, 10, 14, 24, 36, 48, 72 and 96 after birth. Clinical, socio-economic, nutritional and environmental data will be assessed for adverse birth outcomes, impaired growth, immune/neurodevelopment, vertical transmission of HIV, hepatitis-B/C viruses, cytomegalovirus and syphilis. Maternal urine, stool, plasma, cord blood, amniotic fluid, placenta and milk including infant plasma, dried blood spot and stool will be collected at enrolment and follow-up visits. The composite primary endpoint is stillbirth and infant mortality within the first two years of life in HEU versus HUU infants. Maternal mortality in HIV-infected versus -uninfected women is another primary outcome. Secondary endpoints include a range of maternal and infant outcomes. Sub-studies will address maternal stress and malnutrition, maternal-infant latent tuberculosis, Helicobacter pylori infections, immune-metabolomic dysregulation including gut, breast milk and amniotic fluid dysbiosis. DISCUSSION The University of Zimbabwe-College of Health-Sciences-Birth-Cohort study will provide a comprehensive assessment of risk factors and biomarkers for HEU infants' adverse outcomes. This will ultimately help developing strategies to mitigate effects of maternal HIV, early-life ART exposures and comorbidities on infants' mortality and morbidity. TRIAL REGISTRATION ClinicalTrial.gov Identifier: NCT04087239 . Registered 12 September 2019

Validity of oral mucosal transudate specimens for HIV testing using enzyme-linked immunosorbent assay in children in Chimanimani district, Zimbabwe

Objective. To assess the validity of oral mucosal transudate (OMT) specimens for HIV testing in children using enzyme-linked immunosorbent assay (ELISA). Methods. A cross-sectional descriptive study was conducted as part of a community-based behavioural and HIV sero-status survey of adults and children in the Chimanimani district of Zimbabwe. Dried blood spot (DBS) and OMT samples were collected from children aged between 2 and 14 years, inclusive. Both samples were tested for HIV using the Vironostika Uniform II plus O kits. The main study outcomes were the sensitivity and specificity of OMT samples, with DBS as the gold-standard specimen. Results. Paired DBS and OMT specimens were available from 1 274 (94.4%) of the 1 350 children enrolled. Using the DBS, HIV prevalence was 3.2%. Overall sensitivity of OMT was 48.8% (95% confidence interval (CI) 33.3 - 64.5), and specificity was 98.5% (95% CI 97.7 - 99.1). Conclusion. The overall sensitivity of OMT specimens for HIV testing in children using ELISA was low. Stratifying the analysis by sector showed that OMT samples are good specimens for HIV testing. It is important to note that factors such as the low HIV prevalence in our study population, quality of the OMT, diet and oral hygiene could have influenced the results

Current status and future prospects of epidemiology and public health training and research in the WHO African region

Background To date little has been published about epidemiology and public health capacity (training, research, funding, human resources) in WHO/AFRO to help guide future planning by various stakeholders. Methods A bibliometric analysis was performed to identify published epidemiological research. Information about epidemiology and public health training, current research and challenges was collected from key informants using a standardized questionnaire. Results From 1991 to 2010, epidemiology and public health research output in the WHO/AFRO region increased from 172 to 1086 peer-reviewed articles per annum [annual percentage change (APC) = 10.1%, P for trend 90%) reported that this increase is only rarely linked to regional post-graduate training programmes in epidemiology. South Africa leads in publications (1978/8835, 22.4%), followed by Kenya (851/8835, 9.6%), Nigeria (758/8835, 8.6%), Tanzania (549/8835, 6.2%) and Uganda (428/8835, 4.8%) (P < 0.001, each vs South Africa). Independent predictors of relevant research productivity were ‘in-country numbers of epidemiology or public health programmes' [incidence rate ratio (IRR) = 3.41; 95% confidence interval (CI) 1.90-6.11; P = 0.03] and ‘number of HIV/AIDS patients' (IRR = 1.30; 95% CI 1.02-1.66; P < 0.001). Conclusions Since 1991, there has been increasing epidemiological research productivity in WHO/AFRO that is associated with the number of epidemiology programmes and burden of HIV/AIDS cases. More capacity building and training initiatives in epidemiology are required to promote research and address the public health challenges facing the continen