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Alice Muchugi - One of the best experts on this subject based on the ideXlab platform.
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analysis of the impact of domestication of Warburgia ugandensis sprague on its genetic diversity based on amplified fragment length polymorphism
African Journal of Biotechnology, 2016Co-Authors: Nkatha Gacheri, Ramni Jamnadass, Bramwel Wanjala, Alice MuchugiAbstract:Warburgia ugandensis Sprague (Canellaceae) occurs in East and Central Africa and is an important multipurpose tree species. Over-exploitation of natural forests for medicinal purposes and clearance for farming threaten the species survival. Cultivation of the tree species would ensure sustainable medicinal source and its conservation. However, on-farm genetic diversity of the species is currently unknown. The genetic diversity of the on-farm W. ugandensis populations and their proximate natural populations were analyzed using the amplified fragment length polymorphism (AFLP). Four primer combinations produced a total of 223 polymorphic bands. Both the natural and on-farm populations had high genetic diversity ranging from H = 0.2892 to H = 0.1278. Principal co-ordinates analysis and dendrogram separated the ten populations into two major groups corresponding to Kenyan and Tanzanian populations, respectively. Ugandan populations were shared between the two major groups; this is probably because Uganda is believed to be the centre of diversity for W. ugandensis. Close genetic relationships between the on-farm and their proximate natural population were revealed. Analysis of molecular variance (AMOVA) revealed that a total of 54% AFLP variation resided within populations with 46% reside among populations. The high genetic diversity of W. ugandensis on-farm populations could be useful in germplasm collection and conservation strategies. Key words : Warburgia ugandensis, amplified fragment length polymorphism (AFLP), domestication, genetic diversity, on-farm, natural.
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antimicrobial drimane sesquiterpenes and their effect on endophyte communities in the medical tree Warburgia ugandensis
Frontiers in Microbiology, 2014Co-Authors: Sigrid Drage, Ramni Jamnadass, Alice Muchugi, Birgit Mitter, Angela Sessitsch, Franz HadacekAbstract:Metabolite profiles (GC–MS), drimane sesquiterpenes, sugars and sugar alcohols, were compared with bacterial and fungal endophyte communities (T-RFLP, DNA clones, qPCR) in leaves and roots of the pepper bark tree, Warburgia ugandensis (Canellaceae). Ten individuals each were assessed from two locations east and west of the Great Rift Valley, Kenya, Africa, which differed in humidity and vegetation, closed forest versus open savannah. Despite organ- and partially site-specific variation of drimane sesquiterpenes, no clear effects on bacterial and fungal endophyte communities could be detected. The former were dominated by gram-negative Gammaproteobacteria, Pseudomonadaceae and Enterobacteriaceae, as well as gram-positive Firmicutes; the fungal endophyte communities were more diverse but no specific groups dominated. Despite initial expectations, the endophyte community of the pepper bark tree did not differ from other trees that much.
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identification of specific markers linked to regional differentiation of Warburgia ugandensis
Journal of Life Sciences, 2013Co-Authors: Onyango Noel Ochieng, Edward Muge, Alice Muchugi, Bonaventure Omondi Aman, Ramni JamnadassAbstract:Warburgia ugandensis is an important African medicinal tree. The species population has shown a high genetic differentiation in the Kenya's Rift Valley. Nine populations were analysed by Bulk Segregant Analysis employing Random Amplified Polymorphic DNA marker technique to identify regional differentiation-linked markers within and across Kenyan Rift Valley. Five primers showed putative East and West genetic differentiation. Diagnostic markers were isolated, cloned, sequenced and compared with Genbank sequences using BLAST algorithms. Three, (WarburgiaIC15E, WarburgiaIC55E and WarburgiaIC28W) sequences showed homology to plant and bacterial-like chromosomal sequences with low E-values. Sequence alignment indicated conserved protein domains of plants and bacteria-like sequences. Phylogenetic analysis revealed high rates of genetic distances (H" 0.8) and a low rate of disparity indices of (0), suggesting some evolutionary forces behind demographic differentiation. These imply that genetic differentiation observed might be due to genetic mutants in certain domains of chromosome that may have some implication on genome functionality.
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genetic variation of kenyan populations of Warburgia ugandensis an important east african highlands medicinal tree species
Journal of Life Sciences, 2012Co-Authors: Alice Muchugi, Edward Muge, G. M. Muluvi, R. Kindt, Hillary Kipruto, Ramni JamnadassAbstract:Warburgia ugandensis is an important medicinal tree species in Eastern Africa used to treat several ailments. Wild populations are under great threat due to unsustainable harvesting for medicines and indiscriminate felling of trees for timber and firewood. There is an urgent need for developing and implementing conservation strategies of this species and information on genetic structure is a crucial input. Analysis of molecular variance (AMOVA), which employed 141 AFLP markers revealed most genetic variation to be among individuals within populations (59%, P< 0.0001), but variation among populations (41%, P< 0.0001) was highly significant as well. Constrained ordination analysis illustrating the relationship among populations showed a clear distinction between W. ugandensis from Uganda and western Kenya and other W. ugandensis populations. No correspondence was shown in some cases on pair-wise genetic distances and geographic distances among populations. These findings suggested that conservation strategies for the species in Kenya should place relatively more emphasis on the revealed genetic structuring within the country.
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vegetative propagation of Warburgia ugandensis sprague an important medicinal tree species in eastern africa
Journal of Medicinal Plants Research, 2011Co-Authors: Alice Muchugi, F Akwatulira, Samson Gwali, John Bosco Lamoris Okullo, P Ssegawa, S B Tumwebaze, J R MbwamboAbstract:Warburgia ugandensis is an important medicinal tree species whose bark is widely harvested for its valuable anti-bacterial and anti-fungal properties. Consequently, this tree species is considered threatened. Therefore, this species is ranked as one of the priority species for management and conservation. This study investigated an appropriate technique for propagation of W. ugandensis using stem cuttings. Three types of stem cutting (hardwood, semi-hardwood and softwood) were obtained from Mabira Forest Reserve, Uganda and propagated in a factorial experiment using non-misting tunnels. Data on callusing root and shoot formation, number and length of roots and shoots were collected over a period of 93 days. Data manipulation was done by employing general linear model analysis of variance and Chi - square tests. There was significant variation (p < 0.05) in callus formation, root and shoot development, number and length of roots and shoots for different stem cutting types. The highest percentage of callusing, rooting and shoot regeneration (46, 49 and 57%) was recorded in softwood cuttings which also produced the highest number and longest roots and shoots. Successful propagation of W. ugandensis can therefore be appropriately achieved through softwood stem cuttings rather than either hardwood or semi-hardwood cuttings.
Ramni Jamnadass - One of the best experts on this subject based on the ideXlab platform.
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analysis of the impact of domestication of Warburgia ugandensis sprague on its genetic diversity based on amplified fragment length polymorphism
African Journal of Biotechnology, 2016Co-Authors: Nkatha Gacheri, Ramni Jamnadass, Bramwel Wanjala, Alice MuchugiAbstract:Warburgia ugandensis Sprague (Canellaceae) occurs in East and Central Africa and is an important multipurpose tree species. Over-exploitation of natural forests for medicinal purposes and clearance for farming threaten the species survival. Cultivation of the tree species would ensure sustainable medicinal source and its conservation. However, on-farm genetic diversity of the species is currently unknown. The genetic diversity of the on-farm W. ugandensis populations and their proximate natural populations were analyzed using the amplified fragment length polymorphism (AFLP). Four primer combinations produced a total of 223 polymorphic bands. Both the natural and on-farm populations had high genetic diversity ranging from H = 0.2892 to H = 0.1278. Principal co-ordinates analysis and dendrogram separated the ten populations into two major groups corresponding to Kenyan and Tanzanian populations, respectively. Ugandan populations were shared between the two major groups; this is probably because Uganda is believed to be the centre of diversity for W. ugandensis. Close genetic relationships between the on-farm and their proximate natural population were revealed. Analysis of molecular variance (AMOVA) revealed that a total of 54% AFLP variation resided within populations with 46% reside among populations. The high genetic diversity of W. ugandensis on-farm populations could be useful in germplasm collection and conservation strategies. Key words : Warburgia ugandensis, amplified fragment length polymorphism (AFLP), domestication, genetic diversity, on-farm, natural.
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strategies for sustainable supply of and trade in threatened medicinal tree species a case study of genus Warburgia
Ethnobotany Research and Applications, 2014Co-Authors: Stepha Mcmullin, Maarten Nieuwenhuis, Ramni JamnadassAbstract:The use of medicinal tree, shrub, and plant products as a health resource is long-established on the continent of Africa. The continued reliance on such medicinal material and the dominance of its collection from natural populations of species has implications for sustainable use. For many species there is a lack of research on the trade of medicinal material and especially, species-specific data relating to the population, distribution, uses, market prospects, and potential for cultivation. The genus Warburgia Engl. includes four tree species found throughout eastern and southern Africa that are used for their medicinal properties to treat numerous human and livestock diseases. This study was undertaken to assess the supply chain for Warburgia in Kenya through market surveys using questionnaires in the three most populous cities: Nairobi, Kisumu, and Mombasa. Findings from this study indicate that the supply of Warburgia has declined in the last two years and that traders engage in unsustainable practices for addressing supply deficits. These include substitution of species or sourcing species material from different geographical locations. Such strategies can have implications for human and land health. Regional movement of Warburgia for trade is occurring, as it is sourced in Tanzania for trade in Kenyan urban markets. This movement of material indicates a high demand for Warburgia and implies extraneous pressure on available natural resources. The reliance and use of the bark and roots in the markets is a further threat to the use, and alternative, less destructive harvesting strategies should be developed. Normal 0 false false false EN-GB X-NONE X-NONE Normal 0 false false false EN-US X-NONE X-NONE
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antimicrobial drimane sesquiterpenes and their effect on endophyte communities in the medical tree Warburgia ugandensis
Frontiers in Microbiology, 2014Co-Authors: Sigrid Drage, Ramni Jamnadass, Alice Muchugi, Birgit Mitter, Angela Sessitsch, Franz HadacekAbstract:Metabolite profiles (GC–MS), drimane sesquiterpenes, sugars and sugar alcohols, were compared with bacterial and fungal endophyte communities (T-RFLP, DNA clones, qPCR) in leaves and roots of the pepper bark tree, Warburgia ugandensis (Canellaceae). Ten individuals each were assessed from two locations east and west of the Great Rift Valley, Kenya, Africa, which differed in humidity and vegetation, closed forest versus open savannah. Despite organ- and partially site-specific variation of drimane sesquiterpenes, no clear effects on bacterial and fungal endophyte communities could be detected. The former were dominated by gram-negative Gammaproteobacteria, Pseudomonadaceae and Enterobacteriaceae, as well as gram-positive Firmicutes; the fungal endophyte communities were more diverse but no specific groups dominated. Despite initial expectations, the endophyte community of the pepper bark tree did not differ from other trees that much.
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identification of specific markers linked to regional differentiation of Warburgia ugandensis
Journal of Life Sciences, 2013Co-Authors: Onyango Noel Ochieng, Edward Muge, Alice Muchugi, Bonaventure Omondi Aman, Ramni JamnadassAbstract:Warburgia ugandensis is an important African medicinal tree. The species population has shown a high genetic differentiation in the Kenya's Rift Valley. Nine populations were analysed by Bulk Segregant Analysis employing Random Amplified Polymorphic DNA marker technique to identify regional differentiation-linked markers within and across Kenyan Rift Valley. Five primers showed putative East and West genetic differentiation. Diagnostic markers were isolated, cloned, sequenced and compared with Genbank sequences using BLAST algorithms. Three, (WarburgiaIC15E, WarburgiaIC55E and WarburgiaIC28W) sequences showed homology to plant and bacterial-like chromosomal sequences with low E-values. Sequence alignment indicated conserved protein domains of plants and bacteria-like sequences. Phylogenetic analysis revealed high rates of genetic distances (H" 0.8) and a low rate of disparity indices of (0), suggesting some evolutionary forces behind demographic differentiation. These imply that genetic differentiation observed might be due to genetic mutants in certain domains of chromosome that may have some implication on genome functionality.
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genetic variation of kenyan populations of Warburgia ugandensis an important east african highlands medicinal tree species
Journal of Life Sciences, 2012Co-Authors: Alice Muchugi, Edward Muge, G. M. Muluvi, R. Kindt, Hillary Kipruto, Ramni JamnadassAbstract:Warburgia ugandensis is an important medicinal tree species in Eastern Africa used to treat several ailments. Wild populations are under great threat due to unsustainable harvesting for medicines and indiscriminate felling of trees for timber and firewood. There is an urgent need for developing and implementing conservation strategies of this species and information on genetic structure is a crucial input. Analysis of molecular variance (AMOVA), which employed 141 AFLP markers revealed most genetic variation to be among individuals within populations (59%, P< 0.0001), but variation among populations (41%, P< 0.0001) was highly significant as well. Constrained ordination analysis illustrating the relationship among populations showed a clear distinction between W. ugandensis from Uganda and western Kenya and other W. ugandensis populations. No correspondence was shown in some cases on pair-wise genetic distances and geographic distances among populations. These findings suggested that conservation strategies for the species in Kenya should place relatively more emphasis on the revealed genetic structuring within the country.
J Van Staden - One of the best experts on this subject based on the ideXlab platform.
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in vitro culture of two threatened south african medicinal trees ocotea bullata and Warburgia salutaris
Plant Growth Regulation, 2001Co-Authors: B. Kowalski, J Van StadenAbstract:The aim of the project was to develop micropropagation procedures for theheavily exploited and endangered South African trees black stinkwood (Ocotea bullata) and pepperbark (Warburgia salutaris) to facilitateconservation and reforestation. Both species are difficult to establish andgrow in tissue culture because of their high phenolic content. A protocol forthe establishment of explants in vitro was developed comprisingdecontamination, the application of antioxidants and cold treatment.
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isolation of an antibacterial sesquiterpenoid from Warburgia salutaris
Journal of Ethnopharmacology, 2000Co-Authors: T. Rabe, J Van StadenAbstract:Abstract The bark of Warburgia salutaris is used in traditional medicine as an expectorant and smoked for coughs and colds, including a topical application for sores and inflammation. A previous screening of South African medicinal plants showed that this plant had promising antibacterial activity. Subsequently, this endangered tree species was selected for bioassay-guided fractionation in order to identify the active principles. Fractionation of the ethyl acetate extract of the stem bark by chromatographic techniques yielded a sesquiterpenoid which exhibited antimicrobial activity against Gram-positive bacteria. The compound, muzigadial, has previously been reported in two other Warburgia species, this being the first time it has been reported from W. salutaris . Muzigadial had minimum inhibitory concentration values ranging from 12.5 to 100 μg ml −1 .
Ian Edwin Cock - One of the best experts on this subject based on the ideXlab platform.
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anti proteus activity of some south african medicinal plants their potential for the prevention of rheumatoid arthritis
Inflammopharmacology, 2014Co-Authors: Ian Edwin Cock, S F Van VuurenAbstract:A wide variety of herbal remedies are used in traditional African medicine to treat rheumatoid arthritis (RA) and inflammation. Thirty-four extracts from 13 South African plant species with a history of ethnobotanical usage in the treatment of inflammation were investigated for their ability to control two microbial triggers for RA (Proteus mirabilis and Proteus vulgaris). Twenty-nine of the extracts (85.3 %) inhibited the growth of P. mirabilis and 23 of them tested (67.7 %) inhibited the growth of P. vulgaris. Methanol and water extracts of Carpobrotus edulis, Lippia javanica, Pelargonium viridflorum, Ptaeroxylon obliquum, Syzygium cordatum leaf and bark, Terminalia pruinoides, Terminalia sericea, Warburgia salutaris bark and an aqueous extract of W. salutaris leaf were effective Proteus inhibitors, with MIC values <2,000 μg/ml. The most potent extracts were examined by Reverse phase high performance liquid chromatography and UV–Vis spectroscopy for the presence of resveratrol. Only extracts from T. pruinoides and T. sericea contained resveratrol, indicating that it was not responsible for the anti-Proteus properties reported here. All extracts with Proteus inhibitory activity were also either non-toxic, or of low toxicity in the Artemia nauplii bioassay. The low toxicity of these extracts and their inhibitory bioactivity against Proteus spp. indicate their potential for blocking the onset of rheumatoid arthritis.
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Anti-Proteus activity of some South African medicinal plants: their potential for the prevention of rheumatoid arthritis
Inflammopharmacology, 2014Co-Authors: Ian Edwin Cock, S. F. VuurenAbstract:A wide variety of herbal remedies are used in traditional African medicine to treat rheumatoid arthritis (RA) and inflammation. Thirty-four extracts from 13 South African plant species with a history of ethnobotanical usage in the treatment of inflammation were investigated for their ability to control two microbial triggers for RA ( Proteus mirabilis and Proteus vulgaris ). Twenty-nine of the extracts (85.3 %) inhibited the growth of P. mirabilis and 23 of them tested (67.7 %) inhibited the growth of P. vulgaris . Methanol and water extracts of Carpobrotus edulis , Lippia javanica , Pelargonium viridflorum , Ptaeroxylon obliquum , Syzygium cordatum leaf and bark, Terminalia pruinoides , Terminalia sericea , Warburgia salutaris bark and an aqueous extract of W. salutaris leaf were effective Proteus inhibitors, with MIC values
S F Van Vuuren - One of the best experts on this subject based on the ideXlab platform.
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anti proteus activity of some south african medicinal plants their potential for the prevention of rheumatoid arthritis
Inflammopharmacology, 2014Co-Authors: Ian Edwin Cock, S F Van VuurenAbstract:A wide variety of herbal remedies are used in traditional African medicine to treat rheumatoid arthritis (RA) and inflammation. Thirty-four extracts from 13 South African plant species with a history of ethnobotanical usage in the treatment of inflammation were investigated for their ability to control two microbial triggers for RA (Proteus mirabilis and Proteus vulgaris). Twenty-nine of the extracts (85.3 %) inhibited the growth of P. mirabilis and 23 of them tested (67.7 %) inhibited the growth of P. vulgaris. Methanol and water extracts of Carpobrotus edulis, Lippia javanica, Pelargonium viridflorum, Ptaeroxylon obliquum, Syzygium cordatum leaf and bark, Terminalia pruinoides, Terminalia sericea, Warburgia salutaris bark and an aqueous extract of W. salutaris leaf were effective Proteus inhibitors, with MIC values <2,000 μg/ml. The most potent extracts were examined by Reverse phase high performance liquid chromatography and UV–Vis spectroscopy for the presence of resveratrol. Only extracts from T. pruinoides and T. sericea contained resveratrol, indicating that it was not responsible for the anti-Proteus properties reported here. All extracts with Proteus inhibitory activity were also either non-toxic, or of low toxicity in the Artemia nauplii bioassay. The low toxicity of these extracts and their inhibitory bioactivity against Proteus spp. indicate their potential for blocking the onset of rheumatoid arthritis.