• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 451
  • 424
  • 58
  • 45
  • 19
  • 9
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 3
  • Tagged with
  • 1068
  • 1068
  • 405
  • 403
  • 176
  • 161
  • 151
  • 142
  • 122
  • 120
  • 106
  • 93
  • 85
  • 83
  • 82
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
961

Bioprospecting and intellectual property rights on African plant commons and knowledge: a new form of colonization viewed from an ethical perspective

Lenkabula, Puleng 09 1900 (has links)
This study engages in an ethical examination of contemporary socio-ecological and economic issues which takes seriously the plight of Africa, African communities, indigenous knowledge and biodiversity. It studies the impact of bioprospecting, biopiracy and intellectual property rights regimes on the protection, use, access to, and conservation of biodiversity and indigenous knowledge in Africa. The study also examines the ways in which northern multinational pharmaceutical and biotechnology companies and their agents prospect and convert African resources (biological commons and indigenous knowledge) into their intellectual property as well as private property. It argues that the transfer of African biological commons and indigenous knowledge is exacerbated by economic globalisation and the neo-colonial mentality of conquest concealed under the guise of commerce. The study demonstrates through concrete case studies the tactics used by northern multinational corporations to claim these resources as their intellectual property rights and private property. It observes that the privatisation of biological commons and indigenous knowledge only brings about nominal or no benefits to African communities who have nurtured and continue to nurture them. It also observes that this privatisation results in fewer benefits for biodiversity as they lead to the promotion of monoculture, i.e. commercialisation of all things. To address the injustice and exploitative implications of bioprospecting, biopiracy and intellectual property rights, the study recommends the adoption and implementation of the African model law, the establishment of defensive intellectual property rights mechanisms, and the strategy of resistance and advocacy. It suggests that these measures ought to be grounded on the African normative principle of botho and the Christian ethical principle of justice. / Systematic Theology and Theological Ethics / D.Th.(Theological Ethics)
962

Value chain constraints analyses of selected medicinal and aromatic plants indigenous to South Africa

Speirs, Unati Corrie 11 1900 (has links)
Text in English / The introduction of the New Growth Path (NGP) and the New Industrial Policy Framework (NIPF) have created an opportunity for the industrialisation of indigenous medicinal and aromatic plants (MAPs Amarula (Sclerocarya birrea), Buchu (Agathosma betulina), and Pelargonium (Pelargonium sidoides) for job creation and economic development in South Africa. The aim is to create a locally sustainable industry which creates jobs as well as improvement of the balance of payments. The National Growth Plan highlights some of the opportunities for industrialization as well as creation of decent jobs. There is increasing pressure on the harvesting of wild indigenous medicinal and aromatic plants (MAPS). The establishment of a local pharmaceutical and nutraceutical industry for processing MAPS remains a challenge in South Africa and many low income countries. The objective of this study was to assess the challenges and their impact looking at particular species, Amarula, Buchu and Pelargonium by using structured focus group interviews with users in communities and businesses in KwaZulu Natal Province, Eastern Cape and the Western Cape. More data/information was also collected from key stakeholder companies including desk-top reviews. Data/information was analysed using the SPSS computer programme and the Atlas software to summarize data and the results. Graphs and tables were used where necessary. The qualitative research reported on some qualitative assessments and challenges facing the establishment of medicinal and aromatic plants in South Africa. Comparative findings from BRICS were also reported. The results of the study indicated that there is continuous exploitation of several medicinal plant species, for plant trade, from the wild and substantial loss of their habitat. The research identifies a number of challenges such as: poor standards for raw materials, lack of research and development linking industry driven revenues, demand exceeding supply, regulatory risk, community risk, lack of understanding of judicious agronomic practices, ethical challenges, liquidity risk as well as political instability fail to attract foreign direct investments. The research concludes that for the establishment of a viable local pharmaceutical industry, iii beverage industry and nutraceutical industry with sustainable harvesting, there are serious hegemonic challenges which will require multi-stakeholder analysis. However, for the South African (SA) industry to be competitive, detailed feasibility studies need to be done comparing SA with other BRICS countries. There is also a need for the Research and Development to be strengthened. It must also be linked into industrial development in the industry. Furthermore there is a need to initiate the incentivizing of the pharmaceutical manufacturing to lower the cost of setting up the businesses in the industry and lessen the need to harvest from South African forests. Furthermore there is a need for programmes of production so that key species are given opportunity for cultivation and the attention they deserve to preserve these depleting resources. / Agriculture and  Animal Health / M.Sc. (Agriculture)
963

Isolation and characterisation of the active phyto-pharmaceutical ingredient from Lobostemon trigonus for use in the development of a microbicide

Mbobela, Phindiwe Felicia 01 1900 (has links)
The HIV-1 pandemic affects millions of people worldwide with approximately 70% of those affected residing in sub-Saharan Africa (SSA) relying on traditional medicines for treatment. The key aim of the study was to isolate and characterise an active phyto-pharmaceutical ingredient (API) from L. trigonus for use as a vaginal microbicide. The aerial parts of L. trigonus were oven-dried at 80°C, ground and then extracted with boiling water for 30 minutes. Aqueous extracts were screened using an HIV-1 neutralization assay in TZM bl cells. Chromatographic and spectroscopic techniques were used to purify, isolate and identify the API. The API (BP36-117-26464C) was identified as a polymeric macromolecule with IC50 = 0.04 μg/ml against HIV-1 HXB 2 subtype B. This activity is comparable to the ARV drug, enfuvirtide (IC50 = 0.02 μg/ml). The API consists of galacturonic acid polymer and a mixture of seven compounds. Its mode of action may involve inhibiting virus attachment. The activity of this precipitate (BP36-117-26464C) tested against HIV-1 subtype C pseudovirions and shown to compare favorably with that of enfuvirtide (T20). The water-soluble nature of this API and its mode of action identified it as a potential microbicide. In the current form, the precipitate (API) would be difficult to develop as an oral treatment for HIV, as high-molecular weight agents often have poor bioavailability following oral administration. However, large molecules with potent anti-HIV activity are ideal for topical use and potent development as a microbicide. / Life & Consumer Sciences / M.Sc (Life Sciences)
964

Intellectual property rights and the protection of traditional knowledge in Western Cape agriculture

Daya, Yusuf 12 1900 (has links)
Thesis (MComm)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: This study analyses the extent to which the current intellectual property system is suited to the protection of traditional knowledge in the Western Cape. Employing a multidisciplinary approach that incorporates economic and legal theory as well as legal philosophy, this study argues that although advances in the fields of biotechnology has brought with it the need for greater intellectual property rights protection, the protection of traditional knowledge has largely been ignored. Traditional ethnobotanical knowledge holds immense economic value for both commercial entities seeking to develop products based on traditional knowledge as well as for the communities that possess such knowledge. Protecting traditional knowledge is necessary to ensure that the communities contributing their knowledge are recognized and compensated for such contributions. In order for a system to provide adequate protection for traditional knowledge it has to be consistent with and suited to the needs of traditional knowledge holders. This study therefore evaluates the prevailing system of knowledge protection as embodied in the intellectual property rights regime as a means of protecting traditional knowledge. The analysis reveals that the dominant justification for the existence ofIPRs is based on utilitarian considerations that promote IPRs as a necessary incentive encouraging innovative activity. This utilitarian justification also provides the basis for an economic justification for the existence of IPRs that suggests that the conferring of exclusive rights (in the form of IPRs) to innovators ensure that such innovators are able to recover their research costs and realize profits from their inventions. The IPR system as it exists is underpinned by these considerations and embedded in principles of individualism and private property. The WTO reinforces and promotes this approach to intellectual property in the TRIPs agreement by recognizing intellectual property as a 'trade related' issue. The inclusion of IPRs as a 'trade related' issue in the multilateral framework of the WTO reflects the interests of multinational corporations and developed nations who rely extensively on these mechanisms to maintain their power and wealth in an increasingly knowledge driven global economy. The exclusion of traditional knowledge within the TRIPs, coupled with the desire to extend patents to cover life forms is also indicative of this bias inherent in the system. South African intellectual property legislation is then applied to the traditional knowledge of an indigenous medicinal plant to test whether IPRs are able to provide adequate protection to traditional knowledge. In this regard it is found that patent protection, which could potentially provide the greatest form of protection for traditional knowledge is. not suited to the needs of traditional knowledge holders. Problems of identifying owners, determining inventors and novelty, time limited rights and costs all limits the potential of patents as a tool for protecting traditional knowledge. Similar constraints limit the potential of other categories of IPRs to provide protection for traditional knowledge. However, it was found that IPRs do provide a certain measure of defensive protection. The study therefore concludes that the IPR system as it exists, both in the international trade environment as well as at the national level, fails to adequately address the threat of appropriation and the concerns of traditional knowledge holders. Amending the IPR system and/or developing sui generis systems of protection are therefore necessary to ensure that the knowledge of communities are protected and such communities are able to benefit from the exploitation oftheir knowledge and resources. / AFRIKAANSE OPSOMMING: Die doel van hierdie studie is om vas te stel in hoe 'n mate die huidige sisteem vir die beskerming van intellektuele eiendom geskik is vir die beskerming van tradisionele kennis in die Wes-Kaap. 'n Multidissiplinêre benadering, wat uit elemente van ekonomiese- en regsteorie sowel as regsfilosofie haal, is gevolg om te wys dat die beskerming van tradisionele kennis grootliks geïgnoreer is, alhoewel nuwe deurbrake in biotegnologie die behoefte skep vir groter bekerming van intellektuele eiendom. Tradisionele etnobotaniese kennis het geweldige ekonomiese waarde vir beide die kommersiële entiteite wat produkte uit sodanige kennis wil produseer sowel as vir tradisionele gemeenskappe aan wie die kennis behoort. Dus, indien sulke gemeenskappe voordeel wil trek uit hierdie kennis, is dit nodig dat hul bydraes erken moet word, en dat hulle daarvoor vergoed moet word. Sulke beskerming sal net doeltreffend wees indien dit aangepas is by die behoeftes van hierdie gemeenskappe. Dus word die huidige sisteem vir die beskerming van tradisionele kennis geevalueer in hierdie studie. Die ondersoek wys dat die sisteem vir die beskerming van intellektuele eiendom berus op die teoretiese basis van nutsmaksimering, waar die hoofdoel te vinde is in die bydrae wat dit kan maak tot ekonomiese welvaart deur middel van innovasie. In hierdie opsig word beskerming van intellektuele eiendom beskou as 'n manier waardeur die innoveerder sy navorsings- en ontwikkelingskostes kan delg en wins kan maak. Hierdie benadering word onderskryf deur die WTO in die TRIPS Ooreenkoms. In hierdie opsig word die belange van veral die ryk lande en die multinasionale maatskappye bevorder, 'n sleutelvoordeel in 'n wêreld waar kennis gepaardgaan met mag in die mark. Hierdie verskynsel word versterk deur die uitsluiting van tradisionele kennis van die TRIPS Ooreenkoms en die behoefte daaraan om patentregte uit te brei. Suid-Afrikaanse wetgewing oor intellektuele eiendom word vervolgens toegepas op die geval van tradisionele kennis oor 'n inheemse medisinale plant om te toets of intellektuele eiendomsreg genoegsame beskerming aan tradisionele kennis bied. Daar is gevind dat patentregte, wat potensieël die grootste mate van beskerming sou kon bied, nie gepas is in die geval van houers van tradisionele kennis nie. Probleme wat voorkom sluit in die identifisering van eienaars, innoveerders en innoverings, die tydsbeperking op regte, asook kosteoorwegings. Ander vorms van beskerming is aan soortgelyke kritiek onderhewig, alhoewel bevind is dat intellektuele eiendomsreg wel 'n mate van defensiewe beskerming bied. Die gevolgtrekking word dus gemaak dat die huidige vorms van beskerming vir intellektuele eiendomsreg, beide internasionaal sowel as in Suid-Afrika, nie die belange van die houers van tradisionele kennis beskerm nie. Dit is dus nodig om die huidige vorms aan te spreek, of om sui generis beskerming te ontwikkel om hiervoor te sorg.
965

Knowledge and use of traditional medicinal plants by the Setswana-speaking community of Kimberley, Northern Cape of South Africa

Monakisi, Charlotte M. 12 1900 (has links)
Thesis (MSc)--University of Stellenbosch, 2007. / ENGLISH ABSTRACT: The majority of South Africans still depend on the use of traditional remedies, as these are sometimes the only types of health care systems available, especially within rural communities. South Africa comprises approximately 400 000 traditional healers and an estimated 60 to 80% of individuals consulting such traditional healers. As a result, the over-harvesting of many traditional medicinal plants has become a threat to the country’s species diversity and has resulted in the scarcity of certain medicinal plant species. The non-sustainable use of traditional medicinal plants stems from their intense harvesting from the wild to supply the high demands from urban and rural markets. As a result of the escalating population growth rate; high rural unemployment; and fundamental value attached to traditional medicinal plants (socio-economic factors), the national and regional trade of traditional medicines is currently higher than it has ever been. Another reason for the increased threat to traditional medicinal plants is the degradation and weakening of customary laws that have previously regulated such resources. This study focuses on the use of traditional medicinal plants by the Setswana-speaking community for self-medication and as a form of primary health care. Research was conducted in Kimberley, Northern Cape of South Africa and focuses on the issue of the sustainability of medicinal plant use in the area, specifically on use and users as well as the acquisition of material sold by a single trader and harvesting techniques. This is to determine whether harvesting of medicinal plants is a potential threat to plant communities in the area. To address the shortcomings of medicinal anthropology the study also investigates the impacts of relocation and resettlement of various communities in the area, on plant use, methods of collection, the sustainability of the natural resource, as well as the transmission of Setswana indigenous knowledge inter-generationally. most abundant under high disturbances. Certain species reacted positively to disturbance and were most abundant in disturbed habitats. These included Elephantorrhiza elephantina and a Helichrysum sp. To minimise destructive harvesting in the Kimberley area and to ensure the sustainable harvesting of plant material, it is important that local harvesters are educated on proper harvesting techniques and that local gatherers are educated on sustainability issues as well as other ecologically fundamental issues. / AFRIKAANSE OPSOMMING: Die meeste Suid-Afrikaners is steeds afhanklik van tradisionele geneesmiddels aangesien dit soms, veral in landelike gemeenskappe, die enigste beskikbare gesondheidsorg is. Suid-Afrika het sowat 400 000 tradisionele geneeshere wat deur ’n geraamde 60% tot 80% van individue geraadpleeg word. As gevolg hiervan hou die oorontginning van talle tradisionele medisinale-planthulpbronne ’n bedreiging vir die land se spesiediversiteit in en het dit reeds tot ’n skaarste aan sekere medisinale plante gelei. Tradisionele medisinale plante word tans nievolhoubaar aangewend aangesien dit op groot skaal in die veld geoes word om in die groot vraag van stedelike en landelike markte te voorsien. As gevolg van die stygende bevolkingsgroeikoers, hoë landelike werkloosheidsyfer en die grondliggende waarde wat aan tradisionele medisinale plante geheg word (sosio-ekonomiese faktore), is die nasionale en streekhandel in tradisionele geneesmiddels tans groter as ooit tevore. Nog ’n rede vir die toenemende bedreiging van tradisionele medisinale plante is die verslapping en versagting van gewoonteregwetgewing wat voorheen sodanige hulpbronne gereguleer het. Hierdie studie fokus op die gebruik van tradisionele medisinale plante deur die Setswanagemeenskap vir selfbehandeling en as ’n vorm van primêre gesondheidsorg. Die navorsing vir die studie is in Kimberley in die Noord-Kaapprovinsie van Suid-Afrika gedoen en fokus op die kwessie van volhoubare medisinale-plantgebruik in die gebied, met bepaalde klem op gebruik en gebruikers, die verkryging van middels wat deur ’n enkele handelaar verkoop word, en oestegnieke. Die doel van die navorsing was om te bepaal of die oes van medisinale plante ’n moontlike bedreiging vir plantgemeenskappe in die gebied inhou. Om die tekortkominge van medisinale antropologie aan te pak, ondersoek die studie ook die uitwerking van die verskuiwing en hervestiging van verskeie gemeenskappe in die gebied op plantgebruik, oesmetodes, die volhoubaarheid van die natuurlike hulpbronne, asook die oordrag van inheemse Setswana-kennis oor geslagte heen. Selfbehandeling en die gebruik van tradisionele medisinale plante speel steeds ’n groot rol in Kimberley, aangesien die meeste van die individue wat aan die navorsing deelgeneem het steeds tradisionele geneesmiddels as deel van hulle kultuur en tradisie gebruik. Daar word in ’n uiteenlopende verskeidenheid plantmateriaal handel gedryf. Hoewel sommige van die middels plaaslik ingesamel word, word die meeste van ander dele van die land, en in party gevalle van buurlande soos Lesotho en Swaziland, ingevoer. Hoewel die meeste van die materiaal dus nie plaaslik ingesamel word en dus nie bepaald op hierdie studie betrekking het nie, is dit steeds aanduidend van oes- en volhoubaarheidskwessies in ander dele van die land. Die kruiekenner dryf in sewentig tradisionele medisinale-plantsoorte handel, waarvan party beskermd en erg bedreig is, waaronder Prunus africana en Warburgia salutaris wat slegs in beskermde gebiede in die land voorkom. Prunus africana is ’n gelyste spesie in CITES, aanhangsel 2. Ander bedreigde spesies sluit Ocotea bullata, Bersama lucens, Curtisia dentata en ’n Eugenia-spesie in. Die meeste van die plante wat (in Kimberley) geoes word, is in die vorm van ondergrondse bergingsorgane (uitlopers en bolle). Hoewel hierdie plante van stingelskade en die skade aan ondergrondse bergingsorgane kan herstel, vat hulle swak pos indien hulle oorgebruik en oorontgin word, en kan hulle dus mettertyd al hoe minder voorkom. In hierdie studie word die mettertydse afname in plantbevolkings deur die toename in reisafstande na insamelingspunte aangetoon. Hierdie tendens is egter nie in die handelsprys en -materiaalhoeveelhede oor die afgelope eeu weerspieël nie. Die meeste van die studiedeelnemers het bevestig dat die prys en hoeveelheid van die handelsmateriaal deurentyd betreklik stabiel gebly het. Van die teikenspesies wat vir kwesbaarheid of sensitiwiteit vir ontwrigting ondersoek is, het Withania somnifera, Boophane disticha, Dicoma anomala en Bulbine natalensis die laagste oorlewingspotensiaal en die hoogste ontwrigtingsensitiwiteit getoon. Die meeste van hierdie spesies het in baie klein hoeveelhede op die gekose terreine voorgekom. In die geval van Withania somnifera kon die negatiewe resultate egter met die laereënvalseisoen gedurende daardie betrokke jaar in verband gebring word. Hierdie spesie word oor die algemeen as ’n onkruid in ontwrigte gebiede geklassifiseer en kom meestal onder erg ontwrigte toestande voor. Sekere spesies, soos Elephantorrhiza elephantina en ’n Helichrysum-spesie, het positief op ontwrigting gereageer en het volop in ontwrigte habitatte voorgekom. Om vernietigende oestery in die Kimberley-omgewing te minimaliseer en die volhoubare ontginning van planthulpbronne te verseker, is dit belangrik dat plaaslike plukkers in gepaste oestegnieke, en plaaslike insamelaars oor volhoubaarheidskwessies en ander ekologies belangrike sake opgelei word.
966

Inter and intra-specific differences in medicinal plant use for the treatment of type II diabetes symptoms by the Cree Elders of Eeyou Istchee (QC)

Downing, Ashleigh A. 07 1900 (has links)
Au Canada, nous remarquons une prédominance du diabète de type 2 au sein des communautés autochtones. Une approche ethnobotanique est utilisée en collaboration avec la Nation Crie de Eeyou Istchee afin de déterminer quels traitements à base de plantes peuvent être utilisés pour contrer les différentes conditions qui, collectivement, forment le diabète. Les pharmacopées de deux communautés cries, soit celles de Waskaganish et de Nemaska, ont été établies puis comparées à celles de étudiées antérieurement : communautés Whapmagoostui et Mistissini. Malgré les différences géographiques de ces groupes, leurs utilisations sont majoritairement semblables, avec pour seule exception le contraste entre les communautés de Nemaska et de Whapmagoostui. De plus, nous avons complété l’évaluation du taux cytoprotecteur des aiguilles, de l’écorce et des cônes de l’épinette noire (Picea mariana). Les extraits provenant de tous les organes des plantes démontrent une protection qui dépend de la concentration. La réponse spécifique d’organes peut varier selon l’habitat; ainsi, les plantes poussant dans les tourbières ou dans les forêts, sur le littoral ou à des terres l’intérieur démontrent des différences quant à leur efficacité. Bref, l’écorce démontre une relation dose-effet plus forte dans la forêt littorale, tandis que les aiguilles n’indiquent pas de changements significatifs selon leur environnement de croissance. La bioactivité observée démontre une corrélation avec le contenu phénolique et non avec l’activité de l’agent antioxydant. Ces résultats contribuent à péciser les activités antidiabétiques des plantes de la forêt boréale canadienne, telles qu’identifiées au niveau cellulaire par les guérisseurs Cries. / In Canada there is an overwhelming prevalence of type II diabetes in First Nations communities. Here an ethnobotanical approach has been used in cooperation with the Cree Nation of Eeyou Istchee to focus on finding plant based treatments for the conditions which collectively make up the symptoms of diabetes. The pharmacopoeias of two Cree communities (Waskaganish and Nemaska) are elucidated then compared with previously studied populations (Whapmagoostui and Mistissini). Despite differences in north-south east-west geography, plant ranking and use matrices were similar with the exception of Nemaska/Whapmagoostui. We have also completed the evaluation of Black spruce (Picea mariana) needle, bark and cone cytoprotectivity. Extracts from all organs exhibited concentration-dependent protection. Organ-specific response was habitat and growth environment dependent with plants grown either in bog or forest habitats in coastal or inland environments exhibiting differences in efficacy. Observed bioactivity correlated with total phenolic content but not with antioxidant activity. Together, these results contributed to the understanding of antidiabetic activity of Canadian boreal forest plants identified by the Cree of Eeyou Istchee healers at the cellular level.
967

Effets de plantes réputées antidiabétiques sur un modèle cellulaire hépatique de résistance à l’insuline induite par le palmitate

Afshar, Arvind 04 1900 (has links)
La pharmacopée Cris est riche en plantes médicinales et plusieurs d’entre elles sont étudiées par notre laboratoire pour leur potentiel antidiabétique. Certaines espèces ont démontré leur capacité à stimuler la protéine kinase activée par l’AMP (AMPK), une enzyme qui favorise la translocation de transporteurs de glucose à la membrane (effet hypoglycémiant). L’AMPK stimule également d’autres fonctions, telle l’oxydation des graisses, dans le but de rétablir l’énergie cellulaire. Ce projet a comme objectifs d’évaluer, premièrement, le stress métabolique induit par huit des extraits dans des cellules musculaires et des hépatocytes, effet qui serait responsable de l’activation de l’AMPK. Ce stress peut être déterminé en mesurant l’acidification du milieu extracellulaire ainsi que la déplétion du contenu en ATP des cellules suite aux traitements. Le deuxième objectif est de mesurer l’efficacité des extraits à réduire le contenu en gras (oxydation des graisses) et à ainsi normaliser la résistance à l’insuline dans des hépatocytes rendus insulino-résistants. Les hépatocytes sont rendus résistants à l’insuline (condition fortement lié à l’obésité) via traitement avec un acide gras saturé, le palmitate. Les résultats montrent que la majorité des extraits semble induire un stress métabolique de courte durée dans les cellules. Parmi les extraits, seul un a réussi à faire diminuer significativement le taux de triglycérides intracellulaire suite au traitement au palmitate sans toutefois améliorer la sensibilité à l’insuline. En conclusion, le potentiel hypoglycémiant des extraits serait du à leur capacité à affecter la respiration mitochondriale (stress métabolique). Toutefois, leur capacité à améliorer la sensibilité à l’insuline n’a pu être établie. / Cree pharmacopeia is rich in medicinal plants and many of them are studied by our laboratory for their antidiabetic potential. Some of the species tested have shown to activate the AMP-activated protein kinase (AMPK), an enzyme responsible for the translocation of glucose transporters to the cell membrane (hypoglycaemic activity). AMPK is also known to activate other cellular functions, like fat oxidation, in order to restore cell energy loss. The objectives of this study are, first, to measure the metabolic stress induced by eight of the species in muscular and liver cells, an effect believed to be responsible for the AMPK activation. Metabolic stress is evaluated by measuring extracellular medium acidification and cellular ATP depletion. The second objective is to assess the capacity of the extracts to clear intracellular fat (fat oxidation) and, by doing this, restore insulin sensitivity in insulin-resistant driven hepatocytes. To become insulin-resistant (a condition strongly linked to obesity), the hepatocytes are treated with a saturated fatty acid, palmitate. The results show that most of the extracts seem to increase the metabolic stress in muscular cells and hepatocytes for a short period of time. Among all extracts, only one has significantly reduced intracellular triglycerides in palmitate treated hepatocytes, an effect not followed by an increase in insulin sensitivity. In conclusion, the species tested in this study seem to exert their hypoglycaemic potential by affecting mitochondrial respiration (metabolic stress). However, the experimentations have not clearly shown the capacity of the species to restore insulin sensitivity in insulin-resistant liver cells.
968

Inuit ethnobotany and ethnoecology in Nunavik and Nunatsiavut, northeastern Canada

Clark, Courtenay 12 1900 (has links)
Les habitats uniques de l'écotone forêt boréale-subarctique dans le nord du Canada subissent les contrecoups du changement climatique. Combinés aux effets de la mondialisation, les changements environnementaux touchent les Inuits de cette région et imposent des contraintes importantes sur leur mode de vie traditionnel, ce qui a des répercussions sur leur langue et les savoirs qui l'accompagnent. Cette étude compare deux aspects de l’ethnobiologie inuite : a) les noms et les utilisations des plantes par les Inuits de Nain, Nunatsiavut, suivis par une comparaison des utilisations avec la communauté inuite de Kangiqsualujjuaq, Nunavik, et b) une analyse des types de lieux ou d’habitats que les Inuits reconnaissent et nomment. Des interviews semi-dirigés ont été menés à Nain, Nunatsiavut et à Kangiqsualujjuaq, au Nunavik. Les plantes mentionnées sont utilisées comme aliment, thé, médecine, combustible, construction, nettoyage, et autres utilisations. Les deux communautés ont utilisé un nombre égal de plantes, avec des proportions équivalentes de taxons vasculaires/invasculaires, de formes de croissance (habitus), et d’espèces par catégorie d'utilisation. Les éléments du paysage les plus fréquemment rapportés sont d’ordre topographique, hydrologique ou écologique. L’intégration des concepts inuits, quant aux plantes et au paysage, à ceux de la science occidentale peut améliorer notre compréhension de l'écologie subarctique, aider à impliquer les acteurs locaux dans les décisions sur le développement de leur territoire et, conséquemment, modifier l'aménagement du territoire ainsi que les initiatives de conservation de la biodiversité. Ces concepts ont également des répercussions sur les stratégies d'adaptation face aux changements climatiques. / Unique habitats of the boreal-subarctic ecotone in northeastern Canada are being impacted by climate change. Combined with effects of globalization, changing environmental conditions are causing Inuit of this region to see significant strains on their traditional lifestyle and on the language and knowledge that go with it. This study compared two aspects of Inuit ethnobiology: we compared plant names and uses from two Inuit communities and examined what kinds of places or habitats Inuit recognize and name. Semi-structured interviews were conducted in Nain, Nunatsiavut and Kangiqsualujjuaq, Nunavik, by showing interviewees (mostly Elders) plant specimens or photos of the region. Plants were used for food, tea, medicine, fuel, construction, cleaning, and other uses. Both communities used equal numbers of plants, with equivalent proportions of vascular/non-vascular taxa, growth forms, and species per use category. Forty-three species were reported in each community, for a total of 78 species from 39 families. Despite high overlap in species distributions, only half of all species were shared, reflecting community-specific bodies of traditional knowledge, or perhaps an overall decline in ethnobotanical knowledge use. The most frequently reported landscape features were topographical, hydrological, and ecological (i.e. plant associations and animal habitats). Some Inuit categories reflected their significance to traditional Inuit lifestyle (e.g. ‘berry-patch’, ‘seal-place’), aiding navigation and resource finding. Integrating Inuit conceptions of plants and landscape with those of contemporary science can improve our understanding of subarctic ecology, help involve local stakeholders in sustainable development discussions, and inform land-use planning, biodiversity conservation initiatives, and climate change adaptation strategies.
969

Evaluation of biological activities of nine anti-inflammatory medicinal plants and characterization of antimicrobial compounds from Pomaria sandersonii and Alepidea amatymbica

Muleya, Eddwina January 2013 (has links)
D. Tech. (Department of Chemistry, Faculty of Applied and Computer Sciences)|, Vaal University of Technology. / Medicinal plants provide valuable alternative sources of drugs and drug discovery because many have been used in traditional practices for centuries to manage or treat various forms of ailments. The aim of this study was to evaluate the biological activities of nine medicinal plants used by Zulus in Mabandla village, KwaZulu-Natal province, South Africa to treat inflammation and to isolate selected active compounds against studied pathogens from Alepidea amatymbica and Pomaria sandersonii. The plants were selected on the basis of an ethnobotanical survey based on questionnaire response and verbal interviews that were conducted in Mabandla village with the local traditional healers and herbalists. The isolation of compounds from Alepidea amatymbica and Pomaria sandersonii was based on the bioassay based study which was carried out in this study. Bioassay guided study involving in vitro anti-inflammatory measurement using soya bean derived 15 Lipoxygenase, free radical scavenging capacity against the ABTS●+ radical cation and DPPH● radicals; antimicrobial and bioautography assays against Staphylococcus aureus, ATCC 29213, Pseudomonas aeruginosa ATCC 27853, Enterococcus faecalis ATCC 29212, Escherichia coli, ATCC25922, Candida albicans, Cryptococcus neoformans and Aspergillus fumigatus were carried out using the plants extracts, fractions and pure compounds. Isolation of compounds displaying biological activity was carried out by using open column chromatography and preparative thin layer chromatography (PTLC). The compounds were characterised by use of Nuclear Magnetic resonance, (NMR) and Mass Spectrometry (MS). The DPPH sprayed TLC showed that all the nine plants contained antioxidants. Most of which were contained in polar fractions of acetone and methanol. Results of the assays displayed a range of biological activities comparable to the positive controls used for each assay. DPPH● scavenging displayed EC50 values ranging between 1.008 and 467 Kg/ml. The highest activity was observed with the methanol fraction of Berkheya setifera with an EC50 value of 1.008 Kg/ml followed by the crude extract of Gunnera perpensa with EC50 value of 1.069 Kg/ml. Carissa bispinosa hexane fraction had the lowest activity of 467.7 Kg/ml. The Pomaria sandersonii DCM extract had the highest ABTS●+ radical scavenging activity by Pomaria sandersonii DCM extract, (1.273 Kg/ml) for the ethyl acetate, (5.973 Kg/ml) while the hexane fraction from Eucomis autumnalis had the lowest activity (929.4 Kg/ml). The activity of Pomaria sandersonii extracts and fractions demonstrated that the plant contains antioxidants that react with both DPPH and ABTS radicals although higher activities were shown by ABTS as displayed by the lower EC50 values. All the crude fractions and extracts had high to moderate antibacterial activities (20-625 Kg/ml) and anti-fungal activities (20-2500 Kg /ml). Pomaria sandersonii crude and fractions had the highest antimicrobial activity compared to other plants. Some MIC values for P. sandersonii dichloromethane and ethyl acetate fractions (80 Kg/ml in each case) compared well with gentamycin (4 Kg/ml) since they showed same values against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli and Pseudonomus aeruginosa. The dichloromethane, acetone and methanol fractions were also active (20 Kg/ml) against both Candida albicans and Aspergillus fumigatus. Inhibition of pathogen growth demonstrated by the polar fractions of the studied plants suggested that some of the active compounds would be soluble in water. A total of seven compounds were isolated from Alepidea amatymbica and Pomaria sandersonii. We propose three were new compounds after considering literature search involving closely related research to this investigation. These were two diterpenes from Alepidea amatymbica, namely, 14-acetoxo-12-oxokaur-16-en-19-oic acid labelled as 0657 and 16-hydroxy-kaur-6-en-19-oic acid given the label 06-2 in this study. The third suspected new compound is the chalcone dimer, which is referred to as EM86 in this study from Pomaria sandersonii. EM80-2 was obtained as a mixture of the cis and trans of 2’, 4, 4,’-trihydroxychalcone or 1-(2,4-dihydroxyphenyl)-3-(4-hydroxyphenyl)-2-propen-1-one, from Pomaria sandersonii. The three diterpenes, 14-acetoxokaur-16-en-19-oic acid (0652), 13-hydroxy-16-kauren-19-oic acid (06B) and 14-oxokaur-16-en-19-oic acid (06431) were isolated from Alepidea amatymbica for the first time. Isolated compounds were further tested as individual compounds and results showed that 16-hydroxy-kaur-6-en-19-oic acid (06-2) had weak activity against tested bacteria and fungi with the MIC: Staphylococcus aureus (320 Kg/ml) and Candida albicans, (320 Kg/ml). On the other hand 13-hydroxy-kaur-16-en-19-oic acid (06B) was more active against, Staphylococcus aureus (160 Kg/ml) and Aspergillus fumigatus (40 Kg/ml). The yellow compound that was isolated from Pomaria sandersonii, 1-(2, 4-ihydroxyphenyl)-3-(4-hydroxyphenyl)-2-propen-1-one was antimicrobial with the following MICs: Candida albicans: 80 Kg/ml; Pseudomonas aeruginosa, Escherichia coli, Enterococcus faecalis, Staphylococcus aureus: 160 Kg/ml and Aspergillus fumigatus: 625 Kg/ml. There were two mixtures referred to as EM 49 and EM 77 from Pomaria sandersonii which were difficult to purify but had anti-microbial inhibitory activities worth reporting. EM49 had MIC against Candida albicans of: 160μg/ml; Pseudomonas aeruginosa: 320 Kg/ml, Escherichia coli: 80μg/ml, Enterococcus faecalis 80μg/ml, and Staphylococcus aureus: 80μg/ml and Aspergillus fumigatus: 320μg/ml. EM 77 had MIC against Escherichia coli: 80 Kg/ml and Cryptococcus neoformans: 80μg/ml. Further work on their purification need to be done since in this research we are just reporting on their high MIC activities. The medicinal plants used to treat inflammation under different disease conditions in the Zulu community of Mabandla village, Kwa-Zulu Natal, South Africa have some relevant biological activities. The various antimicrobial, antioxidant and anti-inflammatory activities support the validity of their healing capacities that the traditional healers of the community claim to possess. Although there is evidence of good antimicrobial, antioxidant and anti-inflammatory activities by the crude extracts, the high levels of sucrose in P. prunelloides and glucose in G. perpensa should be borne in mind when using their decoctions in traditional medicine particularly by diabetic patients. In vitro results for the antioxidant, antinflammtory and antimicrobial activities carried out in this investigation illustrate that the plants can be a source of treatment and management for inflammation related conditions. These therefore justify their use in Zulu traditional medicine. However, in vivo assays should be carried out in order to completely validate claims by the traditional healers that they treat inflammation related conditions. / Vaal University of Technology
970

Inuit Ethnobotany in the North American Subarctic and Arctic: Celebrating a Rich History and Expanding Research into New Areas Using Biocultural Diversity

Norton, Christian H. 11 1900 (has links)
No description available.

Page generated in 0.0452 seconds