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1.
Planta Med ; 86(1): 10-18, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31731314

RESUMO

The recent publication of a World Scientists' Warning to Humanity highlighted the fact that climate change, absent strenuous mitigation or adaptation efforts, will have profound negative effects for humanity and other species, affecting numerous aspects of life. In this paper, we call attention to one of these aspects, the effects of climate change on medicinal plants. These plants provide many benefits for human health, particularly in communities where Western medicine is unavailable. As for other species, their populations may be threatened by changing temperature and precipitation regimes, disruption of commensal relationships, and increases in pests and pathogens, combined with anthropogenic habitat fragmentation that impedes migration. Additionally, medicinal species are often harvested unsustainably, and this combination of pressures may push many populations to extinction. A second issue is that some species may respond to increased environmental stresses not only with declines in biomass production but with changes in chemical content, potentially affecting quality or even safety of medicinal products. We therefore recommend actions including conservation and local cultivation of valued plants, sustainability training for harvesters and certification of commercial material, preservation of traditional knowledge, and programs to monitor raw material quality in addition to, of course, efforts to mitigate climate change.


Assuntos
Mudança Climática , Plantas Medicinais , Conservação dos Recursos Naturais , Extinção Biológica
2.
BMC Complement Altern Med ; 18(1): 93, 2018 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-29544492

RESUMO

BACKGROUND: Sutherlandia frutescens (L.) R. Br is endemic to Southern Africa where it has been traditionally used for cancer and diabetes. In recent times it has been marketed for its reputed (but not proven) anticancer, antidiabetic and anti-HIV properties. Little is known about the mutagenic and antimutagenic potential of extracts and common marker compounds of Sutherlandia frutescens. Therefore this study aimed to investigate the putative efficacy and possible long-term adverse effects of using this herb. METHODS: Ethylacetate (EA) and 50% Methanol (MeOH) extracts were screened for mutagenic and antimutagenic activity using the Ames assay utilising TA97a, TA98, TA100 and TA102 in the presence and absence of metabolic activation. Four compounds, L-arginine, L-canavanine, GABA and D-pinitol known to occur in sutherlandia were also included. The total polyphenolic content of the both extracts was determined using the Folin-Ciocalteau method and FRAP and ABTS were used to determine the anti-oxidant potential of the extracts. RESULTS: The extracts and the standards did not show any cytotoxicity except in TA97a. The EA extract exhibited antimutagenicity against all the bacterial strains at all concentrations tested. The MeOH extract showed both pro-mutagenic and antimutagenic activities with 2-acetamidofluorene and aflatoxin B1 in the presence of metabolic activation of TA98 and TA100, respectively. All compounds, except L-canavanine exhibited antimutagenic activity against all strains. L-canavanine, on the other hand showed co-mutagenicity with 9-aminoacridine on TA97a, at all test concentrations. The extracts and pure compounds exhibited their antimutagenic activity in a dose response manner. L-arginine and GABA showed an some antimutagenic response. EA extract had three times the total phenolic content (12.56 µg GE / mg) observed in the MeOH extract. There was correlation between total phenolic content, antioxidant potential and antimutagenicity. CONCLUSION: Both extracts exhibited a protective effect, with the EA extract exhibiting greater potency. L-canavanine acted as a co-mutagen in a dose response manner without metabolic activation. It is suggested that the EA extract be priotized for future development work as it showed a better risk profile and activity.


Assuntos
Antimutagênicos/farmacologia , Fabaceae/química , Mutagênicos/farmacologia , Extratos Vegetais/farmacologia , África Austral , Antimutagênicos/química , Antimutagênicos/isolamento & purificação , Mutagênese/efeitos dos fármacos , Testes de Mutagenicidade , Mutagênicos/química , Mutagênicos/isolamento & purificação , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/genética
3.
J Appl Toxicol ; 37(4): 395-399, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-27933645

RESUMO

Aflatoxins are highly toxic fungal metabolites produced by some members of the Aspergillus species. They are low molecular weight lipophilic compounds that are easily absorbed from the gastrointestinal tract. They contaminate most staple foods, including maize, peanuts, peanut butter and sorghum mainly in the tropics where hot and humid conditions promote fungal growth. Absorbed aflatoxins are metabolized by the cytochrome P450 enzyme system in the liver into toxic metabolites. Aflatoxin B (AFB)1 is the most toxic, carcinogenic and mutagenic naturally occurring toxin. Aflatoxin exposure assessment has been traditionally achieved through food use frequency questionnaires and laboratory analysis of food samples. However, estimation of individual exposure to aflatoxins based on these methods may not be accurate. The use of aflatoxin biomarkers in urine and blood for use in exposure studies has emerged in more recent times. However, the current biomarkers (e.g., AFB-N7 -guanine and AFB1 -albumin adduct) in use have a short half-life and are only practically useful to indicate levels over 24 h-3 months post-exposure. There is therefore an immediate need to study and evaluate alternative biomarkers in non-conventional matrices such as hair and nails. Hair analysis revealed considerable interest in forensic analysis particularly in the detection of drugs of abuse where it has emerged as a sensitive and specific technique complementary to blood and urinalysis. This article provides an overview of aflatoxins, current aflatoxin biomarkers and proposes the use of hair as a potential matrix for biomarkers of long-term aflatoxin exposure. Copyright © 2016 John Wiley & Sons, Ltd.


Assuntos
Aflatoxinas/análise , Aflatoxinas/toxicidade , Biomarcadores/análise , Cabelo/química , Aflatoxinas/metabolismo , Animais , Humanos
5.
BMC Complement Altern Med ; 14: 99, 2014 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-24621275

RESUMO

BACKGROUND: Salvia africana-lutea L., an important medicinal sage used in the Western Cape (South Africa), can be termed a 'broad-spectrum remedy' suggesting the presence of a multiplicity of bioactive metabolites. This study aimed at assessing wild S. africana-lutea populations for chemotypic variation and anti-Fusarium properties. METHODS: Samples were collected from four wild growing population sites (Yzerfontein, Silwerstroomstrand, Koeberg and Brackenfell) and one garden growing location in Stellenbosch. Their antifungal activities against Fusarium verticillioides (strains: MRC 826 and MRC 8267) and F. proliferatum (strains: MRC 6908 and MRC 7140) that are aggressive mycotoxigenic phytopathogens were compared using an in vitro microdilution assay. To correlate antifungal activity to chemical profiles, three techniques viz. Gas chromatography-mass spectrometry (GC-MS); Liquid chromatography-mass spectrometry (LC-MS) and 1H Nuclear Magnetic Resonance (NMR) were employed. Principal Component Analysis (PCA) was applied to the NMR data. The partial least squares-discriminant analysis (PLS-DA) was used to integrate LC-MS and NMR data sets. All statistics were performed with the SIMCA-P+12.0 software. RESULTS: The dichloromethane:methanol (1:1; v/v) extracts of the plant species collected from Stellenbosch demonstrated the strongest inhibition of F. verticillioides and F. proliferatum with minimum inhibitory concentration (MIC) values of 0.031 mg ml(-1) and 0.063 mg ml(-1) respectively. GC-MS showed four compounds which were unique to the Stellenbosch extracts. By integrating LC-MS and 1H NMR analyses, large chemotype differences leading to samples grouping by site when a multivariate analysis was performed, suggested strong plant-environment interactions as factors influencing metabolite composition. Signals distinguishing the Stellenbosch profile were in the aromatic part of the 1H NMR spectra. CONCLUSIONS: This study shows the potential of chemotypes of Salvia africana-lutea in controlling fungal growth and consequently mycotoxin production. Products for use in the agricultural sector may be developed from such chemotypes.


Assuntos
Antifúngicos/farmacologia , Fusarium/efeitos dos fármacos , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Salvia/química , Salvia/metabolismo , Antifúngicos/química , Cromatografia Gasosa-Espectrometria de Massas , Espectroscopia de Ressonância Magnética , Metabolômica , Extratos Vegetais/química
6.
Heliyon ; 9(11): e22218, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38045165

RESUMO

A national medicine policy (NMP), formerly referred to as a national drug policy (NDP) is a document that serves as a political commitment and guide for action by the government to provide safe, efficacious, quality assured, available, affordable and rationally used medicines. This is the first study to review the implemented components of the NMPs of the 16 South African Development Community (SADC) countries over the past ten years (2011-2021). Information published between 2011 and 2021 of each country such as pharmaceutical profiles, official government documents, WHO/HAI/World Bank datasets and research studies on the implemented components were appraised. Significant progress has been made by 16 SADC countries over the period 2011-2021 in implementing the NMP. The most commonly implemented components included the concept of essential medicines, pricing, and regulation. Though traditional and herbal medicines component is yet to be implemented by the majority. The pharmacist-patient ratio of 1:2300 was below the target for all countries, prompting the need to strengthen the pharmacy personnel in the healthcare systems. Medicine pricing, affordability, and availability studies are necessary to develop equitable pricing policies that will improve the accessibility of medicines in all countries and the SADC region. With the exception of the Republic of Tanzania, SADC countries need to urgently revise their NMPs, thus adopting progressive processes such as incorporating Health Technology Assessment (HTA) in the NMP. All SADC countries require a strong, internationalistic evaluation culture built-in their policy formulation. As the first study to investigate the implemented NMPs in the SADC region, it could serve as a springboard for the countries to address their common pharmaceutical challenges thus improving their readiness for universal health coverage (UHC). Future in-depth cross-country studies in the SADC region are necessary to comprehensively evaluate the implemented components of NMPs.

7.
BMJ Glob Health ; 8(8)2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37558269

RESUMO

Management of COVID-19 in Africa is challenging due to limited resources, including the high cost of vaccines, diagnostics, medical devices and routine pharmaceuticals. These challenges, in addition to wide acceptability, have resulted in increased use of herbal medicines based on African traditional medicines (ATMs) by patients in Africa. This is in spite of the often-significant gaps in evidence regarding these traditional medicines as to their efficacy and safety for COVID-19. African scientists, with some support from their governments, and guidance from WHO and other bodies, are addressing this evidence gap, developing and testing herbal medicines based on ATMs to manage mild-to-moderate cases of COVID-19. Such efforts need further support to meet public health needs.


Assuntos
COVID-19 , Humanos , Medicinas Tradicionais Africanas , Pandemias , África , Extratos Vegetais
8.
J Ethnopharmacol ; 286: 114867, 2022 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-34822956

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: In South Africa, medicinal plants have a history of traditional use, with many species used for treating wounds. The scientific basis of such uses remains largely unexplored. AIM OF THE STUDY: To screen South African plants used ethnomedicinally for wound healing based on their pro-angiogenic and wound healing activity, using transgenic zebrafish larvae and cell culture assays. MATERIALS AND METHODS: South African medicinal plants used for wound healing were chosen according to literature. Dried plant material was extracted using six solvents of varying polarities. Pro-angiogenesis was assessed in vivo by observing morphological changes in sub-intestinal vessels after crude extract treatment of transgenic zebrafish larvae with vasculature-specific expression of a green fluorescent protein. Subsequently, the in vitro anti-inflammatory, fibroblast proliferation and collagen production effects of the plant extracts that were active in the zebrafish angiogenesis assay were investigated using murine macrophage (RAW 264.7) and human fibroblast (MRHF) cell lines. RESULTS: Fourteen plants were extracted using six different solvents to yield 84 extracts and the non-toxic (n=72) were initially screened for pro-angiogenic activity in the zebrafish assay. Of these plant species, extracts of Lobostemon fruticosus, Scabiosa columbaria and Cotyledon orbiculata exhibited good activity in a concentration-dependent manner. All active extracts showed negligible in vitro toxicity using the MTT assay. Lobostemon fruticosus and Scabiosa columbaria extracts showed noteworthy anti-inflammatory activity in RAW 264.7 macrophages. The acetone extract of Lobostemon fruticosus stimulated the most collagen production at 122% above control values using the MRHF cell line, while all four of the selected extracts significantly stimulated cellular proliferation in vitro in the MRHF cell line. CONCLUSIONS: The screening of the selected plant species provided valuable preliminary information validating the use of some of the plants in traditional medicine used for wound healing in South Africa. This study is the first to discover through an evidence-based pharmacology approach the wound healing properties of such plant species using the zebrafish as an in vivo model.


Assuntos
Anti-Inflamatórios/farmacologia , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Cicatrização/efeitos dos fármacos , Animais , Animais Geneticamente Modificados , Anti-Inflamatórios/isolamento & purificação , Linhagem Celular , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Humanos , Inflamação/tratamento farmacológico , Inflamação/patologia , Larva , Macrófagos/efeitos dos fármacos , Macrófagos/patologia , Medicinas Tradicionais Africanas , Camundongos , Células RAW 264.7 , África do Sul , Peixe-Zebra
9.
Plants (Basel) ; 10(5)2021 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-33922037

RESUMO

Plants that exhibit foaming properties when agitated in aqueous solutions are commonly referred to as soapy plants, and they are used in different communities for washing, bathing, and hair shampooing. The frothing ability of these plants is attributed to saponins which are also well-documented to possess antimicrobial attributes. In the light of COVID-19, soap and hand hygiene have taken center stage. The pandemic has also revealed the low access to running water and commercial soaps in many marginalized and poor communities to the detriment of global health. Thus, soapy plants, either in their natural form or through incorporation in commercial products, may be a relevant additional weapon to assist communities to improve hand hygiene and contribute to curbing COVID-19 and other communicable infections. This review paper was compiled from a review of literature that was published between 1980 and 2020. We found 68 plant species, including those which are already used as traditional soaps. Our findings support the potential use of extracts from soapy plants because of their putative viricidal, bactericidal, and fungicidal activities for use in crude home-based formulations and possibly for developing natural commercial soap products.

10.
South Afr J HIV Med ; 22(1): 1200, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33936791

RESUMO

BACKGROUND: The proportion of individuals with a history of exposure ('pre-exposure') to antiretrovirals (ARVs) prior to formal initiation into antiretroviral treatment (ART) is unknown. OBJECTIVES: This study describes the detection of ARVs in plasma and/or hair, of persons who self-reported no pre-exposure to ART at their first-time initiation onto ART in three clinics in the province of Limpopo, South Africa (SA). METHOD: Concentrations of tenofovir (TDF), emtricitabine (FTC) and efavirenz (EFV) in the plasma and hair of individuals initiating ART were analysed using a validated liquid chromatography tandem mass spectrometry (LC-MS/MS) method. Next generation sequences of HIV polymerase gene were analysed with Geneious software 11.15, and drug resistance (DR) mutations were determined according to the Stanford HIV Drug-Resistance database. Participants' demographic data were collected on a structured questionnaire. Data that describe prior exposure to ARV were also collected by this self-reporting method. RESULTS: Paired blood and hair samples were collected from 77 individuals newly initiated onto ART from 2017 to 2019. We detected at least one of the drugs in the plasma or hair of 41/77 (53.2%) patients who responded with a 'no' to the question 'have you received ARVs before initiation onto ART?' Thirty-one participants (n = 31/77, 40.3%) had TDF in either plasma or hair. Emtricitabine and EFV were found in the plasma or hair of 12/77 (15.6%) and 25/77 (32.4%) of participants respectively. Six (n = 6/77, 7.792%) had all three ARVs in plasma or hair. Prevalence of DR mutations at the > 5% significance threshold level in those known to have had ARV-exposure determined by LC-MS/MS prior to ART-initiation was not significant (χ2 = 0.798; p = 0.372), when compared to those who had no prior exposure but still showed DR. CONCLUSION: Antiretroviral levels in the hair of individuals initiating treatment imply prolonged prior-exposure to that ARV. The presence of ARV in plasma and hair of persons living with HIV (PLWH) who deny ARV-use, requires an explanation. A larger study at multiple sites and regular DR surveillance of ART-naïve PLWH will be necessary to confirm the generalisability of these findings to the wider South African population.

11.
Toxins (Basel) ; 13(8)2021 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-34437441

RESUMO

Analysis of body fluids and tissues of aflatoxin exposed individuals for the presence of aflatoxins and aflatoxin metabolites has emerged as a reliable indicator of exposure and metabolism of aflatoxins. However, current aflatoxin biomarkers are not appropriate for investigating the long-term effects of aflatoxin exposure. In this explorative study, we investigated the analysis of hair as a complementary or alternative matrix for the assessment of biomarkers of long-term aflatoxin exposure. Three groups of guinea pigs were orally dosed with 5 ugkg-1bw-1, 50 ugkg-1bw-1, and 100 ugkg-1bw-1 of AFB1. Urine and hair samples were collected on days 0, 1, 2, 3, 7, 30, 60, and 90 and analysed for AFB1 and AFM1 using UHPLC-MS/MS. AFB1 and AFM1 were detected in 75% and 13.6%, respectively, of the day 1 to day 7 urine samples. AFB1 was detected in hair samples collected from day 3 up to day 60. This is the first report to confirm the deposition of AFB1 in the hair of experimental animals. These findings indicate that hair analysis has the potential to provide an accurate long-term historical record of aflatoxin exposure with potentially important implications for the field of aflatoxin biomarkers.


Assuntos
Aflatoxinas/análise , Aflatoxinas/toxicidade , Aflatoxinas/urina , Biomarcadores/análise , Biomarcadores/urina , Monitoramento Ambiental/métodos , Cabelo/química , Animais , Relação Dose-Resposta a Droga , Cobaias , Modelos Animais , África do Sul , Fatores de Tempo
12.
J AOAC Int ; 93(6): 1882-7, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21313816

RESUMO

A new method that uses HPLC with a photochemical reactor for enhanced detection was developed and validated for the determination of aflatoxins in cassava flour. Samples were spiked with a mixture of four aflatoxins at 5, 10, and 20 microg/kg mixed with either 1 or 5 g NaCI and extracted with methanol-water (80 + 20, v/v) by shaking for 10 or 30 min. An immunoaffinity column was used for cleanup. HPLC with postcolumn derivatization, for enhancement of aflatoxin fluorescence, and fluorescence determination were used for quantitation of the toxin concentration. The method was validated for recovery, linearity, and precision at the three concentrations tested. Recovery ranges were 52-70, 69-85, and 80-89% for the spiking levels of 5.0, 10.0, and 20.0 microg/kg, respectively. It appears that the amount of salt (NaCl) and the shaking time are critical factors in this method; optimal performance was obtained when 1 g salt was used and the shaking time was 10 min. The good linearity and precision of the method allowed baseline separation from interferences, e.g., coumarins.


Assuntos
Aflatoxinas/análise , Carcinógenos/análise , Manihot/química , Cromatografia Líquida de Alta Pressão , Raízes de Plantas/química , Padrões de Referência , Reprodutibilidade dos Testes , Cloreto de Sódio/análise , Extração em Fase Sólida , Solventes , Espectrofotometria Ultravioleta
13.
Afr Health Sci ; 19(2): 2219-2229, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31656507

RESUMO

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.


Assuntos
Annona/química , Glicemia/metabolismo , Transportador de Glucose Tipo 4/metabolismo , Células Musculares/metabolismo , Extratos Vegetais/farmacologia , Glicemia/efeitos dos fármacos , Linhagem Celular , Células Cultivadas , Relação Dose-Resposta a Droga , Transportador de Glucose Tipo 4/efeitos dos fármacos , RNA Mensageiro/metabolismo , Wortmanina/farmacologia , Zimbábue
14.
J Pharm Sci ; 107(10): 2720-2730, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29936204

RESUMO

To assess drug quality and pharmaceutical care in South Africa, "mystery" (i.e., anonymous) customers collected 316 samples from July to September 2016. Solid dosage forms containing amoxicillin alone or in combination with clavulanic acid as well as analgesics containing paracetamol alone or in combination with other drugs were sampled in a randomized fashion from the formal market (pharmacies) and by convenient sampling from the informal market. Visual inspection, uniformity of dosage units, and dissolution testing were performed to evaluate adherence to pharmacopoeial quality standards and to identify counterfeit, degraded, or substandard drugs. Although no counterfeited products were identified, only 55.4% (173/312) of samples were able to fulfill all pharmacopeial requirements for quality. Most of the 139 samples that failed were unable to pass the visual inspection due to inappropriate labeling and packaging. In addition, several substandard products were identified: 17 (5.4%) samples failed dissolution testing and 15 (4.8%) failed the content uniformity test. To improve drug quality and the quality of pharmaceutical care, better education of pharmaceutical professionals and monitoring of the pharmaceutical supply chain in South Africa are needed. Further field studies are necessary to evaluate risks and quality issues for other drug classes and distribution channels.


Assuntos
Formas de Dosagem/normas , Preparações Farmacêuticas/normas , Acetaminofen/normas , Amoxicilina/normas , Ácido Clavulânico/normas , Medicamentos Falsificados/química , Embalagem de Medicamentos/normas , Controle de Qualidade , Solubilidade , África do Sul
15.
J AOAC Int ; 90(1): 162-6, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17373447

RESUMO

The performance of 4 purification methods for the analysis of patulin in apple juice was evaluated by high-performance liquid chromatography (HPLC). Samples were spiked with patulin at 10, 20, 50, 100, and 150 ppb (ng/mL) and extracted by one of 4 methods (3 solid-phase extraction and one liquid-liquid extraction), and then analyzed by HPLC-UV under the same isocratic conditions. The methods were validated for recovery, linearity, and precision at high and low concentrations. Recoveries were all >70% for spiking range 10-150 ppb. The relative standard deviation for repeatability was found to meet European Union Directive requirements. In addition, all the methods showed baseline separation from hydroxymethylfurfural.


Assuntos
Bebidas/análise , Malus/química , Patulina/isolamento & purificação , Cromatografia Líquida de Alta Pressão/métodos , União Europeia , Furaldeído/análogos & derivados , Furaldeído/isolamento & purificação , Patulina/química , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Raios Ultravioleta
16.
Nutrients ; 9(12)2017 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-29186859

RESUMO

Peanuts (Arachis hypogaea) is an important and affordable source of protein in most of Sub-Saharan Africa (SSA) and a popular commodity and raw material for peanut butter, paste and cooking oil. It is a popular ingredient for foods used at the point of weaning infants from mother's milk. It is at this critical point that childhood undernutrition occurs and the condition manifests as stunting, wasting and growth restriction and accounts for nearly half of all deaths in children under five years of age in SSA. Undernutrition is multi-factorial but weaning foods contaminated with microbiological agents (bacteria and fungi) and natural toxins have been shown to play a big part. While peanuts may provide good nutrition, they are also highly prone to contamination with mycotoxigenic fungi. The high nutritive value of peanuts makes them a perfect substrate for fungal growth and potential aflatoxin contamination. Aflatoxins are highly carcinogenic and mutagenic mycotoxins. This article reviews the nutritional value and aflatoxin contamination of peanuts, the role they play in the development of childhood malnutrition (including the different theories of aetiology) and immunological problems in children. We also discuss the control strategies that have been explored and advocacy work currently taking shape in Africa to create more awareness of aflatoxins and thus combat their occurrence with the goal of reducing exposure and enhancing trade and food safety.


Assuntos
Aflatoxinas/análise , Arachis/química , Arachis/microbiologia , Contaminação de Alimentos/análise , Desnutrição/epidemiologia , África Subsaariana/epidemiologia , Criança , Carboidratos da Dieta/administração & dosagem , Gorduras na Dieta/administração & dosagem , Fibras na Dieta/administração & dosagem , Proteínas Alimentares/administração & dosagem , Microbiologia de Alimentos , Inocuidade dos Alimentos , Humanos , Micronutrientes/administração & dosagem , Valor Nutritivo
17.
PLoS One ; 12(10): e0185887, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28982162

RESUMO

Currently beer is booming, mainly due to the steady rise of craft breweries worldwide. Previous surveys for occurrence of mycotoxins in beer, were mainly focussed on industrial produced beer. The present survey reports the presence of mycotoxins in craft beer and how this compares to industrial produced beer. More than 1000 beers were collected from 47 countries, of which 60% were craft beers. A selection of 1000 samples were screened for the presence of aflatoxin B1, ochratoxin A (OTA), zearalenone (ZEN), fumonisins (FBs), T-2 and HT-2 toxins (T-2 and HT-2) and deoxynivalenol (DON) using a mycotoxin 6-plex immunoassay. For confirmatory analysis, a liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed and applied. The 6-plex screening showed discrepancies with the LC-MS/MS analysis, possibly due to matrix interference and/or the presence of unknown mycotoxin metabolites. The major mycotoxins detected were DON and its plant metabolite deoxynivalenol-3-ß-D-glucopyranoside (D3G). The 6-plex immunoassay reported the sum of DON and D3G (DON+D3G) contaminations ranging from 10 to 475 µg/L in 406 beers, of which 73% were craft beers. The popular craft beer style imperial stout, had the highest percentage of samples suspected positive (83%) with 29% of all imperial stout beers having DON+D3G contaminations above 100 µg/L. LC-MS/MS analysis showed that industrial pale lagers from Italy and Spain, predominantly contained FBs (3-69 µg/L). Besides FBs, African traditional beers also contained aflatoxins (0.1-1.2 µg/L). The presence of OTA, T-2, HT-2, ZEN, ß-zearalenol, 3/15-acetyl-DON, nivalenol and the conjugated mycotoxin zearalenone 14-sulfate were confirmed in some beers. This study shows that in 27 craft beers, DON+D3G concentrations occurred above (or at) the Tolerable Daily Intake (TDI). Exceeding the TDI, may have a health impact. A better control of brewing malts for craft beer, should be put in place to circumvent this potential problem.


Assuntos
Cerveja/microbiologia , Micotoxinas/análise , Cromatografia Líquida , Limite de Detecção , Espectrometria de Massas em Tandem
18.
J Agric Food Chem ; 53(23): 9293-6, 2005 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-16277436

RESUMO

The fumonisin mycotoxins are mainly produced by the fungi Fusarium verticillioides and Fusarium proliferatum, which are both field pathogens of maize. The natural occurrence of fumonisins has been verified in maize and a large range of maize-based products in many countries of the world. However, occasional reports have emerged of fumonisins being detected in wheat, despite the main producing fungi not being pathogens of this cereal. An investigation was conducted into a recent report of the natural occurrence of fumonisins in the 2003/2004 South African wheat crop at levels up to 1.7 mg/kg, as determined by immunoaffinity column cleanup and direct fluorometric measurement. An AOAC International high-performance liquid chromatographic (HPLC) method for the determination of fumonisins in maize was modified and validated for the determination of fumonisins in spiked wheat samples. HPLC analysis of the wheat samples previously found to be positive for fumonisins revealed no detectable (<5 microg/kg) fumonisins in the 30 samples analyzed. These results, which lay doubt on previous reports of fumonisins in wheat, emphasize the fact that screening methods, especially if used outside their range or matrix of applicability, can produce false positive results despite the use of immunoaffinity cleanup. Such results should be validated and confirmed with a more definitive technique.


Assuntos
Fumonisinas/análise , Triticum/química , Cromatografia Líquida de Alta Pressão , Fusarium/crescimento & desenvolvimento , Fusarium/metabolismo , Triticum/microbiologia , Zea mays/química
19.
Phytochemistry ; 65(4): 433-8, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-14759537

RESUMO

A dichloromethane extract of the aerial parts of Combretum albopunctatum Suesseng afforded five phenolic compounds-three known flavonoids and two novel cyclobutane chalcone dimers. The chemical structures were determined by standard spectroscopic techniques and the structure and relative stereochemistry of one chalcone dimer, rel-(1 alpha,2 beta)-di-(2,6-dimethoxy-4-hydroxy)-benzoyl-rel-(3 alpha,4 beta)-diphenylcyclobutane, were confirmed by single crystal X-ray diffraction.


Assuntos
Combretum/química , Ciclobutanos/química , Ciclobutanos/isolamento & purificação , Chalcona/análogos & derivados , Chalcona/isolamento & purificação , Dimerização , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Componentes Aéreos da Planta/química , Extratos Vegetais/química , Estereoisomerismo , Difração de Raios X
20.
Phytochemistry ; 63(1): 81-8, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12657301

RESUMO

Four pentacyclic tritepenes were isolated from Combretum imberbe Engl. & Diels, of which two are novel glycosidic derivatives of 1alpha,3beta,23-trihydroxyolean-12-en-29-oic acid (hydroxyimberbic acid). Terminalia stuhlmannii Engl. & Diels stem bark yielded two glycosides of hydroxyimberbic acid, one of which is reported for the first time. The structures of the isolated compounds were elucidated by spectroscopic methods. Several of the compounds had antibacterial activity, imberbic acid showing particularly potent activity against Mycobacterium fortuitum and Staphylococcus aureus.


Assuntos
Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Plantas Medicinais/química , Terminalia/química , Triterpenos/isolamento & purificação , Triterpenos/farmacologia , Antibacterianos/química , Testes de Sensibilidade Microbiana , Mycobacterium fortuitum/efeitos dos fármacos , Ressonância Magnética Nuclear Biomolecular , Casca de Planta/química , Folhas de Planta/química , Staphylococcus aureus/efeitos dos fármacos , Triterpenos/química
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