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1.
J Pharm Policy Pract ; 15(1): 3, 2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-34986899

RESUMO

BACKGROUND: Substandard and Falsified (SF) medical products are a growing global concern. They harm the individual patient, the healthcare system and the economy. The World Health Organisation (WHO) has highlighted contributing factors globally: insufficient national medicine regulation, poor enforcement of existing legislation, weak stakeholder collaboration and the rise of novel viruses, such as the COVID-19. The study aimed to assess the legislative and policy framework and institutional relationships governing pharmaceuticals and anti-counterfeiting strategies. METHODS: The study was explorative and consisted of two phases. The first phase was between 2016 and 2017. It looked at document analysis (annual reports and press releases from 2011 to 2016) from government institutions involved in medicines regulation and law enforcement for SF seizure reports between 2004 and 2017. The second phase was between 2016 and 2018 through in-depth semi-structured interviews (seven in total) with selected stakeholders. RESULTS: First Phase-the data collected and reported by various departments was sporadic and did not always correlate for the same periods indicating, a lack of a central reporting system and stakeholder collaboration. In South Africa, counterfeiting of medicines mainly involves the smuggling of non-registered goods. The most common counterfeit items were painkillers, herbal teas, herbal ointments, while some were medical devices. Furthermore, Customs identified South Africa as a transhipment point for SF infiltration to neighbouring countries with less robust regulatory systems. Second phase-interview transcripts were analysed by thematic coding. These were identified as the adequacy of legislation, institutional capacity, enforcement and post-market surveillance, stakeholder collaboration and information sharing, and public education and awareness. CONCLUSION: Document analysis and interviews indicate that South Africa already has a national drug policy and legislative framework consistent with international law. However, there is no specific pharmaceutical legislation addressing the counterfeiting of medicines. Law enforcement has also been complicated by poor stakeholder engagement and information sharing.

2.
J Ethnopharmacol ; 194: 1103-1111, 2016 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-27836776

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Clausena anisata is used traditionally by various communities across Africa against pests such as mosquitoes, flies and weevils among others. Pests are a major cause of disease and production losses in various crop and livestock production systems in Africa. This review discusses the available information on the occurrence, chemistry, biological activity and possible commercialization of Clausena anisata with a view to see the plant species being integrated in pest management. MATERIALS AND METHODS: Information on the ethnomedical use, chemistry and biological activity of C. anisata published between 1980 and 2016 was accessed from various databases namely Science Direct, Springer Link and Wiley Online Library. In addition various relevant books were also consulted. RESULTS: The crude extracts as well as different fractions of C. anisata have been evaluated for activity against various insect pests and have been shown to be active. Furthermore, close to 50 compounds have been isolated and identified from C. anisata, which include coumarins, carbazole alkaloids, limonoids and essential oils (monoterpenes). Some of these compounds have been proven to exhibit pesticidal properties in both laboratory and field studies against various pests including mosquitoes, flies and weevils. The possible mechanisms of action of these compounds have been explored in this review. CONCLUSION: The results of pesticidal and phytochemical screening of C. anisata strongly indicate that the species is endowed with pesticidal properties that can be harnessed into commercial products. However, one glaring challenge in the evaluation of this plant species for pesticidal activity has been the non-availability of standard testing systems. Researchers have used various methods which they developed based on their own circumstances and resources. Formulation, standard appropriate testing systems and agronomic research are key in unlocking the potential of this important African species.


Assuntos
Clausena/química , Insetos/efeitos dos fármacos , Controle de Pragas/métodos , Extratos Vegetais/farmacologia , África , Animais , Humanos , Extratos Vegetais/química
3.
Artigo em Inglês | MEDLINE | ID: mdl-26600208

RESUMO

The aim of this study was to assess mycotoxin contamination of crops grown by rural subsistence farmers over two seasons (2011 and 2012) in two districts, Vhembe District Municipality (VDM, Limpopo Province) and Gert Sibande District Municiality (GSDM, Mpumalanga Province), in northern South Africa and to evaluate its impact on farmers' productivity and human and animal health. A total of 114 maize samples were collected from 39 households over the two seasons and were analysed using a validated liquid chromatography-tandem mass spectrometry mycotoxins method. Aflatoxin B1 (AFB1) occurrence ranged from 1 to 133 µg kg(-1) in VDM while AFB1 levels in GSDM were less than 1.0 µg kg(-1) in all maize samples. Fumonisin B1 levels ranged from 12 to 8514 µg kg(-1) (VDM) and 11-18924 µg kg(-1) (GSDM) in 92% and 47% positive samples, respectively, over both seasons. Natural occurrence and contamination with both fumonisins and aflatoxins in stored home-grown maize from VDM was significantly (p < 0.0001) higher than from GSDM over both seasons.


Assuntos
Poluentes Ambientais/química , Análise de Alimentos , Contaminação de Alimentos , Micotoxinas/química , Zea mays/química , Agricultura , Armazenamento de Alimentos , Humanos , África do Sul
4.
J Ethnopharmacol ; 164: 203-9, 2015 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-25683299

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Infusions of Tulbaghia violacea (wild garlic) in water are used in traditional medicine in Southern Africa to treat numerous diseases, including cancer. Several studies have previously demonstrated the cytotoxic activities of extracts of T. violacea in cultured cancer cells. Their findings support the potential anti-cancer properties of this plant. However, these studies made use of organic solvent extraction methods, while the traditional use of the plant involves the preparation of infusions in water. MATERIALS AND METHODS: In the current study, we investigated the potential anti-cancer properties of infusions of T. violacea. We also performed a comparative study investigating the cytotoxic activities of T. violacea bulbs and leaves. A panel of four cancer cell lines (HepG2, MCF7, H157, and HT29) and one non-cancerous cell line (KMST6) was treated with the two extracts and the effects of the extracts on the growth of the cells were evaluated. We also investigated whether the growth inhibitory effects were associated with the induction of apoptosis and whether the mechanism of cell death is the result of oxidative stress and the activation of caspase-3. RESULT: We found that extracts of the leaves and not the bulbs have growth inhibitory effects and that this is the result of the induction of apoptosis, which is associated with the production of Reactive Oxygen Species (ROS) and the activation of caspase-3. The leaf extract demonstrated variable selective toxicity towards the cancer lines. Although the extract also induced cell death in the non-cancerous cell line (KMST6), we found that the levels of toxicity were lower in this cell line. CONCLUSION: this study confirms that infusions of T. violacea have potential anti-cancer activity and that this bioactivity is contained in the leaf extract. This study lends support to claims that this plant can be used to treat cancer.


Assuntos
Allium , Antineoplásicos/farmacologia , Extratos Vegetais/farmacologia , Folhas de Planta/química , Raízes de Plantas/química , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Linhagem Celular , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos , Espécies Reativas de Oxigênio/metabolismo , Solventes/química , Água/química
5.
J Food Prot ; 77(10): 1814-8, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25285504

RESUMO

Mycotoxins are toxic secondary metabolites produced by filamentous fungi that may contaminate food and pose a health risk, especially in developing countries, where there is a lack of food security and quality is subsumed by food insufficiency. Aflatoxins are the most toxic known mycotoxins and are a significant risk factor for liver and kidney cancer, teratogenicity, undernutrition, and micronutrient malabsorption in both humans and animals. The main aim of the study was to determine the extent of fungal and aflatoxin contamination in peanuts and peanut butter being sold in both the formal and informal markets in Bulawayo, Zimbabwe. Eighteen peanut samples and 11 peanut butter samples were purchased from retail shops and the informal market. Fungal contamination was determined using standard mycology culture methods, while aflatoxin contamination was determined using high-performance liquid chromatography-fluorescence detection. Four of the six peanut samples tested for fungal contamination were infected with Aspergillus flavus/parasiticus, ranging from 3 to 20% of the kernels examined, while 27% (3 of 11) of the peanut butter samples were infected with A. flavus/parasiticus. Ninety-one percent (10 of 11) of the peanut butter samples were contaminated with aflatoxins (mean, 75.66 ng/g, and range, 6.1 to 247 ng/g), and aflatoxin B1 was the most prevalent (mean, 51.0 ng/g, and range, 3.7 to 191 ng/g). Three of the 18 peanut samples were contaminated with aflatoxins (range, 6.6 to 622 ng/g). The commercial peanut butter samples had very high aflatoxin levels, and manufacturers should be sensitized to the detrimental effects of aflatoxins and measures to reduce contamination.


Assuntos
Aflatoxinas/análise , Arachis/microbiologia , Aspergillus/isolamento & purificação , Contaminação de Alimentos/análise , Microbiologia de Alimentos/métodos , Aflatoxina B1/análise , Cromatografia Líquida de Alta Pressão , Qualidade de Produtos para o Consumidor , Fungos/isolamento & purificação , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Zimbábue
6.
Pharm Biol ; 52(6): 756-61, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24559378

RESUMO

CONTEXT: Numerous plants are used by the local communities of South Africa for the treatment and management of type II diabetes. OBJECTIVES: For this study, we undertook a survey of the plants sold for the management of diabetes in the town of Newcastle, South Africa. Identified plants were subsequently evaluated for their in vitro antidiabetic activity. MATERIALS AND METHODS: Plants were identified through an interview with a herbalist at the market. Antidiabetic activity of extracts of purchased plants was evaluated using in vitro α-amylase and α-glucosidase activity, as well as islets of Langerhans excretory activity. RESULTS: Senna alexandrina Mill. (Fabaceae), Cymbopogon citrates Stapf. (Poaceae), Cucurbita pepo L. (Cucuribitaceae), Nuxia floribunda Benth. (Stilbaceae), Hypoxis hemerocallidea Fisch. and Mey (Hypoxidaceae), and Cinnamomum cassia Blume (Lauraceae) were identified. The hexane extract of S. alexandrina (EC50=0.083 mg/ml), ethyl acetate extract of H. hemerocallidea (EC50=0.29 mg/ml), and methanol extracts of Cymbopogon citratus (EC50=0.31 mg/ml) and Cinnamomum cassia (EC50=0.12 mg/ml) had the highest α-amylase inhibitory activity, albeit lower than acarbose (EC50=0.50 mg/ml). All the plants had good α-glucosidase inhibitory activity (>50%) with the exception of some methanol (Cinnamomum cassia, N. floribunda, and Cymbopogon citratus) and acetone extracts (Cucurbita pepo and N. floribunda). Only the H. hemerocallidea acetone extract had an insulin stimulatory effect (2.5 U/ml at 8 µg/ml). CONCLUSION: All the evaluated plants demonstrated inhibitory activity against the specific GIT enzyme systems evaluated. Only H. hemerocallidea had insulin secretory activity, adding evidence to the traditional use of these purchased plants in the management of the type II diabetic post-prandial hyperglycemia.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Extratos Vegetais/uso terapêutico , Plantas Medicinais , Animais , Células Cultivadas , Diabetes Mellitus Tipo 2/sangue , Avaliação Pré-Clínica de Medicamentos/métodos , Hipoglicemiantes/isolamento & purificação , Hipoglicemiantes/farmacologia , Ilhotas Pancreáticas/efeitos dos fármacos , Ilhotas Pancreáticas/metabolismo , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Ratos , Ratos Sprague-Dawley , África do Sul , Resultado do Tratamento
7.
J Appl Microbiol ; 109(4): 1479-86, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20553341

RESUMO

AIMS: To investigate the antifungal activity of aqueous and organic extracts of four weedy plant species viz. Tagetes minuta, Lippia javanica, Amaranthus spinosus and Vigna unguiculata against isolates of four agriculturally important fungi, i.e. Fusarium verticillioides, F. proliferatum, Aspergillus flavus and A. parasiticus. METHODS AND RESULTS: Dried powdered aerial parts of the plants were extracted sequentially with hexane, dichloromethane, methanol and water and tested for activity using a serial microdilution assay. Results were read every day over 120 h. All extracts except for the water extracts showed growth inhibitory activity against most isolates of the Fusarium spp. The most active were the methanol and hexane extracts of V. unguiculata and A. spinosus with minimum inhibitory concentration (MIC) values of <0.5 mg ml(-1) after 48 h against Fusarium spp. No inhibition of the Aspergillus spp. tested was observed, but conidium formation was stimulated on plates treated with plant extracts when visually compared to the growth controls. CONCLUSIONS: The results obtained from this study indicated that chemical constituents from these plant species may be developed as potential agrochemical fungicides. SIGNIFICANCE AND IMPACT OF THE RESEARCH: Food and feed are subject to infection by a variety of micro-organisms that can induce spoilage and/or produce metabolites that are toxic to humans and animals. Extracts of V. unguiculata and A. spinosus were most active and maybe developed into environmentally friendly fungicides, which are affordable to rural farmers in developing countries.


Assuntos
Antifúngicos/farmacologia , Aspergillus/efeitos dos fármacos , Fusarium/efeitos dos fármacos , Plantas Daninhas , Amaranthus , Fabaceae , Lippia , Testes de Sensibilidade Microbiana , Micotoxinas/metabolismo , Extratos Vegetais/farmacologia , Tagetes
8.
J Ethnopharmacol ; 119(3): 686-99, 2008 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-18805474

RESUMO

AIM OF THE STUDY: Members of the Combretaceae family are widely traded in the traditional medicine market in southern Africa. The family is also used for medicinal purposes in the rest of Africa and Asia for close to 90 medicinal indications. Many of these indications are related to treating infections. This contribution summarizes work done to date and identifies avenues for future research. MATERIALS AND METHODS: Substantial work has already been done on the chemistry of especially Combretum and Terminalia species over many years. During the last decade we have focussed on bio-assay guided isolation of biologically active compounds with the aim of producing new effective antimicrobial products. RESULTS AND DISCUSSION: Methods developed to facilitate this process and data on 25 compounds isolated from 7 species are presented. The large majority of compounds isolated were known, but the biological activities were not known. In practically all cases the antibacterial or antifungal activity of compounds isolated were much lower than expected from the activity of the crude extracts. It appears that synergism plays a role in antimicrobial activity of plant extracts and that the hope of isolating a single compound that can be used as a new agent to address antibiotic resistance has been frustrated. By simple manipulation such as selective extraction the activity of some crude extracts could however, be increased substantially and this offers a new approach to address antibiotic resistance via the herbal medicine industry. Practically all extracts obtained using intermediate polarity extractants had reasonable to very good activity with MICs as low as 40 microg/ml, validating the traditional use for infectious diseases. Aqueous extracts however, generally had hardly any activity. CONCLUSIONS: The Combretaceae contains a diversity of antimicrobial compounds. Because poor people usually have only water available as extractant, it raises the question how plants growing in poor rural communities can be used to treat infections more effectively, and what the mechanism of activity of aqueous extracts used to treat infections in traditional medicine are.


Assuntos
Combretaceae/química , Animais , Antibacterianos/farmacologia , Antifúngicos/química , Antifúngicos/farmacologia , Antioxidantes/farmacologia , Antiparasitários/farmacologia , Antivirais/farmacologia , Bactérias/efeitos dos fármacos , Combretaceae/anatomia & histologia , Combretaceae/classificação , Combretaceae/toxicidade , Etnobotânica , Humanos , Medicina Tradicional Africana , Testes de Sensibilidade Microbiana , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Extratos Vegetais/toxicidade , África do Sul
9.
Hum Exp Toxicol ; 27(11): 793-8, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19244286

RESUMO

Traditional medicine is an important aspect of healthcare delivery in South Africa and is used by at least 70% of the country's population. The trade in medicinal plants is a multi-million rand business which is a major driver for rural economies. However, the conditions in which these plant products are transported and stored make them prone to fungal contamination which results in economic losses to the traders and pose potential health hazards to consumers. Of major concern is the possible presence of toxigenic fungi and mycotoxins. This study assessed fungal and mycotoxin contamination of African herbal products sold in Cape Town and Tshwane (formerly Pretoria) in South Africa. Of the 16 samples analyzed, 15 were contaminated with at least one of these three fungal genera: Aspergillus, Fusarium, and Penicillium. Fumonisin B(1) was present in 13 of the samples in quantities ranging from 14 to 139 microg/kg (detection limit 5 microg/kg). None of the samples was contaminated with aflatoxigenic fungi or aflatoxin (detection limit 0.5 microg/kg). This is the first study to report on mycological and mycotoxin contamination of commercial traditional African medicines in South Africa. There is a need to expand the study to other urban centers to gain enough insight into this problem and then to intervene with measures that can protect the public from potential harm.


Assuntos
Aflatoxinas/análise , Contaminação de Medicamentos , Fumonisinas/análise , Medicina Tradicional Africana , Micotoxinas/análise , Preparações de Plantas/efeitos adversos , Aflatoxina B1/análise , Cromatografia Líquida de Alta Pressão , Fungos/química , Indicadores e Reagentes , Preparações de Plantas/análise , Preparações de Plantas/normas , Plantas Medicinais/microbiologia , África do Sul
10.
Food Addit Contam ; 24(6): 630-4, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17487604

RESUMO

A study of apple juice products sold in Italy and South Africa was initially carried out on 20 samples bought in Cesena, Italy, and Tygerberg in Cape Town, South Africa. The samples were bought at random and analysed for patulin contamination. All 12 of the Italian samples had no detectable levels of patulin, except one, which was just slightly above the lowest regulatory limit of 10 ng ml(-1). On the other hand, five of the eight South African samples were all contaminated with patulin levels above 10 ng ml(-1), with one showing a concentration of 75 ng ml(-1), well above the highest regulated limit of 50 ng ml(-1). This latter result led to a more targeted investigation with 14 samples being purchased in the low-income areas of Tygerberg where the initial samples were sourced. These samples confirmed that there might be a problem of mycotoxin contamination in apple juices products sold to low-income consumers because half of the samples showed patulin contamination of which four had levels well above the acceptable limits. This is the first study in South Africa to look at apple juice products in low-income areas and it points to a need to intervene and introduce quality systems in the supply chain of the manufacture and packaging of apple juice products by independent small business.


Assuntos
Bebidas/análise , Contaminação de Alimentos/análise , Malus/química , Patulina/análise , Cromatografia Líquida de Alta Pressão/métodos , Análise de Alimentos/métodos , Itália , Mutagênicos/análise , África do Sul
11.
J Ethnopharmacol ; 93(2-3): 207-12, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15234754

RESUMO

Preliminary studies with Combretum erythrophyllum showed antimicrobial activity against Gram-positive and Gram-negative bacteria. Seven antibacterial flavonoids were subsequently isolated by bioassay-guided fractionation, i.e. apigenin; genkwanin; 5-hydroxy-7,4'-dimethoxyflavone, rhamnocitrin; kaempferol; quercetin-5,3'-dimethylether; rhamnazin. All compounds had good activity against Vibrio cholerae and Enterococcus faecalis, with MIC values in the range of 25-50 microg/ml. Rhamnocitrin and quercetin-5,3'-dimethylether also inhibited Micrococcus luteus and Shigella sonei at 25 microg/ml. With the exception of 5-hydroxy-7,4'-dimethoxy-flavone the flavonoids were not toxic towards human lymphocytes. This compound is potentially toxic to human cells and exhibited the poorest antioxidant activity whereas rhamnocitrin and rhamnazin exhibited strong antioxidant activity. Genkwanin; rhamnocitrin; quercetin-5,3'-dimethylether; rhamnazin had a higher anti-inflammatory activity than the positive control mefenamic acid. Although these flavonoids are known, this is the first report of biological activity with several of these compounds.


Assuntos
Antibacterianos/farmacologia , Combretum , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Fitoterapia , Extratos Vegetais/farmacologia , Antibacterianos/administração & dosagem , Antibacterianos/uso terapêutico , Aspergillus niger/efeitos dos fármacos , Flavonoides/administração & dosagem , Flavonoides/farmacologia , Flavonoides/uso terapêutico , Humanos , Testes de Sensibilidade Microbiana , Extratos Vegetais/administração & dosagem , Extratos Vegetais/uso terapêutico , Folhas de Planta
12.
Cent Afr J Med ; 46(1): 9-13, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14674200

RESUMO

OBJECTIVE: To investigate the effects of Heteromorpha trifoliata on rat uterine and skeletal muscle. DESIGN: Laboratory based study using experimental animals. Investigating the effects of the plant extract and agonists on isolated muscle preparations. SETTING: Department of Physiology, University of Zimbabwe. SUBJECTS: 28 Sprague-Dawley rats. MAIN OUTCOME MEASURES: Amplitude of contraction of uterine smooth muscle and skeletal muscle. RESULTS: Experiments were performed on the isolated rat uterus preparation in which strips of myometrium were placed in tissue baths filled with Kreb's solution. The aqueous extract of the root bark of Heteromorpha trifoliata ("dombwe") contracted the rat uterus. The contractions were not antagonised by atropine but were blocked by both cyproheptadine and verapamil. In addition, "dombwe" induced a contracture of the rat diaphragm muscle in the presence of alcuronium. CONCLUSIONS: The contractile effects on the uterus appear to involve stimulation of 5-HT2 receptors leading to an increase in calcium influx into the smooth muscle cell. Promotion of calcium influx could also explain the effects observed on the skeletal muscle preparation since the contracture induced by "dombwe" occurred in the presence of the nicotinic antagonist, alcuronium. In view of the effects of "dombwe" on other smooth muscle preparations (from previous work) it appears that the pharmacological profile of the crude aqueous extract of the root bark of Heteromorpha trifoliata is complex and suggestive of the presence of more than one active ingredient.


Assuntos
Apiaceae/fisiologia , Medicina Tradicional Africana , Contração Muscular/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Miométrio/efeitos dos fármacos , Fitoterapia/métodos , Extratos Vegetais/farmacologia , Contração Uterina/efeitos dos fármacos , Alcurônio/farmacologia , Animais , Atropina/farmacologia , Bloqueadores dos Canais de Cálcio/farmacologia , Ciproeptadina/farmacologia , Avaliação Pré-Clínica de Medicamentos , Feminino , Técnicas In Vitro , Masculino , Antagonistas Muscarínicos/farmacologia , Antagonistas Nicotínicos/farmacologia , Casca de Planta/fisiologia , Extratos Vegetais/agonistas , Extratos Vegetais/antagonistas & inibidores , Ratos , Ratos Sprague-Dawley , Receptores 5-HT2 de Serotonina/efeitos dos fármacos , Antagonistas da Serotonina/farmacologia , Verapamil/farmacologia , Zimbábue
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