28 research outputs found

    Serotonin transporter affinity of (−)-loliolide, a monoterpene lactone from Mondia whitei

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    AbstractMondia whitei (Apocynaceae) is used in traditional medicine to treat nervous disorders. Previous studies have shown in vivo antidepressant-like activity in the forced swimming test and affinity to the serotonin transporter of an ethanolic leaf extract of M. whitei. The aim of this study was to isolate the compound(s) responsible for in-vitro serotonin transporter affinity in M. whitei. Bioassay guided isolation lead to the identification of the monoterpene lactone (−)-loliolide. An ethanol extract was prepared from dry leaves. The residue was dissolved in ethyl acetate, extracted with water by liquid–liquid partitioning. This was followed by VLC fractionation. Through HPLC-UV separation the active compound was isolated and characterized by GC-MS, LC-MS and 1H-NMR. The activity of (−)-loliolide was tested in a serotonin transporter binding assay using [3H]-citalopram as ligand, giving an IC50-value of 997µM, corresponding to a Ki-value of 409µM. Loliolide is a non-nitrogenous compound and might bind to the transporter in a different way to nitrogen-containing inhibitors. The results provide a rationale for the use of M. whitei in the treatment of depression and other central nervous system diseases in traditional medicine

    Global burden and strength of evidence for 88 risk factors in 204 countries and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

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    Background: Understanding the health consequences associated with exposure to risk factors is necessary to inform public health policy and practice. To systematically quantify the contributions of risk factor exposures to specific health outcomes, the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 aims to provide comprehensive estimates of exposure levels, relative health risks, and attributable burden of disease for 88 risk factors in 204 countries and territories and 811 subnational locations, from 1990 to 2021. Methods: The GBD 2021 risk factor analysis used data from 54 561 total distinct sources to produce epidemiological estimates for 88 risk factors and their associated health outcomes for a total of 631 risk–outcome pairs. Pairs were included on the basis of data-driven determination of a risk–outcome association. Age-sex-location-year-specific estimates were generated at global, regional, and national levels. Our approach followed the comparative risk assessment framework predicated on a causal web of hierarchically organised, potentially combinative, modifiable risks. Relative risks (RRs) of a given outcome occurring as a function of risk factor exposure were estimated separately for each risk–outcome pair, and summary exposure values (SEVs), representing risk-weighted exposure prevalence, and theoretical minimum risk exposure levels (TMRELs) were estimated for each risk factor. These estimates were used to calculate the population attributable fraction (PAF; ie, the proportional change in health risk that would occur if exposure to a risk factor were reduced to the TMREL). The product of PAFs and disease burden associated with a given outcome, measured in disability-adjusted life-years (DALYs), yielded measures of attributable burden (ie, the proportion of total disease burden attributable to a particular risk factor or combination of risk factors). Adjustments for mediation were applied to account for relationships involving risk factors that act indirectly on outcomes via intermediate risks. Attributable burden estimates were stratified by Socio-demographic Index (SDI) quintile and presented as counts, age-standardised rates, and rankings. To complement estimates of RR and attributable burden, newly developed burden of proof risk function (BPRF) methods were applied to yield supplementary, conservative interpretations of risk–outcome associations based on the consistency of underlying evidence, accounting for unexplained heterogeneity between input data from different studies. Estimates reported represent the mean value across 500 draws from the estimate's distribution, with 95% uncertainty intervals (UIs) calculated as the 2·5th and 97·5th percentile values across the draws. Findings: Among the specific risk factors analysed for this study, particulate matter air pollution was the leading contributor to the global disease burden in 2021, contributing 8·0% (95% UI 6·7–9·4) of total DALYs, followed by high systolic blood pressure (SBP; 7·8% [6·4–9·2]), smoking (5·7% [4·7–6·8]), low birthweight and short gestation (5·6% [4·8–6·3]), and high fasting plasma glucose (FPG; 5·4% [4·8–6·0]). For younger demographics (ie, those aged 0–4 years and 5–14 years), risks such as low birthweight and short gestation and unsafe water, sanitation, and handwashing (WaSH) were among the leading risk factors, while for older age groups, metabolic risks such as high SBP, high body-mass index (BMI), high FPG, and high LDL cholesterol had a greater impact. From 2000 to 2021, there was an observable shift in global health challenges, marked by a decline in the number of all-age DALYs broadly attributable to behavioural risks (decrease of 20·7% [13·9–27·7]) and environmental and occupational risks (decrease of 22·0% [15·5–28·8]), coupled with a 49·4% (42·3–56·9) increase in DALYs attributable to metabolic risks, all reflecting ageing populations and changing lifestyles on a global scale. Age-standardised global DALY rates attributable to high BMI and high FPG rose considerably (15·7% [9·9–21·7] for high BMI and 7·9% [3·3–12·9] for high FPG) over this period, with exposure to these risks increasing annually at rates of 1·8% (1·6–1·9) for high BMI and 1·3% (1·1–1·5) for high FPG. By contrast, the global risk-attributable burden and exposure to many other risk factors declined, notably for risks such as child growth failure and unsafe water source, with age-standardised attributable DALYs decreasing by 71·5% (64·4–78·8) for child growth failure and 66·3% (60·2–72·0) for unsafe water source. We separated risk factors into three groups according to trajectory over time: those with a decreasing attributable burden, due largely to declining risk exposure (eg, diet high in trans-fat and household air pollution) but also to proportionally smaller child and youth populations (eg, child and maternal malnutrition); those for which the burden increased moderately in spite of declining risk exposure, due largely to population ageing (eg, smoking); and those for which the burden increased considerably due to both increasing risk exposure and population ageing (eg, ambient particulate matter air pollution, high BMI, high FPG, and high SBP). Interpretation: Substantial progress has been made in reducing the global disease burden attributable to a range of risk factors, particularly those related to maternal and child health, WaSH, and household air pollution. Maintaining efforts to minimise the impact of these risk factors, especially in low SDI locations, is necessary to sustain progress. Successes in moderating the smoking-related burden by reducing risk exposure highlight the need to advance policies that reduce exposure to other leading risk factors such as ambient particulate matter air pollution and high SBP. Troubling increases in high FPG, high BMI, and other risk factors related to obesity and metabolic syndrome indicate an urgent need to identify and implement interventions. Funding: Bill & Melinda Gates Foundation

    In vitro cytotoxic and mutagenic evaluation of thirteen commercial herbal mixtures sold in KwaZulu-Natal, South Africa

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    AbstractCytotoxic and mutagenic effects of thirteen commercial herbal mixtures sold in KwaZulu-Natal, South Africa were evaluated using the neutral red uptake (NRU) assay and the Ames test. The herbal mixtures tested included Umzimba omubi, Umuthi wekukhwehlela ne zilonda, Mvusa ukunzi, Umpatisa inkosi, Imbiza ephuzwato, Vusa umzimba, Ingwe® muthi mixture, Ibhubezi™, Supreme one hundred™, Sejeso herbal mixture Ingwe®, Lion izifozonke Ingwe®, Stameta™ BODicare® and Ingwe® special muti. The relative cytotoxicity of the herbal mixtures was established by determining their NI50 values (50% inhibition of neutral red uptake). The test revealed that the most toxic herbal mixture was Umpatisa inkosi with an NI50 value of 0.016mg/mL and the least toxic mixture was Stameta™ BODicare® with an NI50 value of 28.00mg/mL. The herbal mixtures showed no mutagenic effects against Salmonella typhimurium tester strains TA98, TA100, TA102, TA1535 and TA1537 when the assay was done without S9 metabolic activation. However, four herbal mixtures, Umpatisa inkosi, Imbiza ephuzwato, Vusa umzimba and Stameta™ BODicare® showed mutagenic effects against TA98 but not the rest of the tester strains after using S9 metabolic activation. Umpatisa inkosi also exhibited weak mutagenic activity against TA1535 after metabolic activation. The remaining mixtures did not show mutagenic effects against all the tester strains after S9 metabolic activation. The cytotoxic and mutagenic results reported here offer a step toward determining the safety of commercial herbal mixtures in South Africa. Herbal mixtures showing higher cytotoxic and mutagenic effects need to be further investigated for their possible effects on humans

    Acetylcholinesterase inhibitory activity of plants used as memory- enhancers in traditional South African medicine

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    In traditional South African medicine there are a few plants used to improve memory and to treat Alzheimer's disease. Aqueous and ethanol extracts of five of these plants: Malva parviflora (leaves), Boophane disticha (leaves and bulbs), Albizia adianthifolia (stem bark), Albizia suluensis (root bark) and Crinum moorei (bulbs) were investigated. They were screened for acetylcholinesterase (AChE) inhibiting activity using thin- layer chromatography (TLC) and microtitre plate assays. Inhibition of AChE is an important approach in treating Alzheimer's disease. Promising results were obtained with bulbs of B. disticha and C. moorei. The aqueous and ethanol extracts of B. disticha (0.1mgml−1) yielded 38% and 27% inhibition in the microplate assay, respectively, while the ethanol extract of C. moorei had good dose-dependent inhibiting activity with 67% inhibition at the highest concentration. Aqueous and ethanol extracts of C. moorei and B. disticha showed AChE inhibiting activity in the TLC assay
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