Abstracts
Zealand weed risk assessment was used to assess the potential invasiveness of the species and Southern African Plant Invaders Atlas for locality data and data collected by the authors from 2010 to 2014. To determine the potential distribution of V. thapsus we developed a species distribution model using MaxEnt 3.3.3e. The distribution map and habitat records indicated that the species has managed to establish in natural areas. Risk assessment results and the species distribution model indicate that the species has a high potential of being invasive in South Africa, with Cape Floristic Region being the most likely region to be colonised by V. thapsus. V. thapsus is a pioneer species and can thrive in a variety of habitats including natural grasslands, disturbed areas, roadsides, pastures and forest margins. This species is still on its early stages of naturalisation and therefore needs to be regulated and managed before it becomes a major problem.
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as being used by traditional healers and community members. The bulb of this species was exclusively uprooted for the herbal preparation. There is currently no effective management strategies used to conserve or preserve the aforementioned species. Only one population of S. aethiopicus with limited number of individuals was observed in the wild. Thus, it indicates an urgent need for the domestication of this species. doi:10.1016/j.sajb.2015.03.173
What is killing Acacia erioloba trees in the Kathu region of the Northern Cape Province? C. Ncedanaa,b, D. Pavlic-Zupanca, J. Rouxb Biosystematics Programme-Mycology Unit, Plant Protection Research Institute, Agricultural Research Council (ARC-PPRI), Pretoria 0001, South Africa b DST/NRF Centre of Excellence in Tree Health Biotechnology (CTHB), Forestry and Agricultural Biotechnology Institute (FABI), Department of Microbiology and Plant Pathology, University of Pretoria, Private Bag X20, Pretoria 0028, South Africa a
doi:10.1016/j.sajb.2015.03.171
The anticancer activity and phytochemical analysis of six methanol extracts T.E. Ntimane, I.D. Manduna, S.S. Mashele Department of Health Sciences, School of Health and Environmental Sciences, Central University of Technology, Free State, Private Bag X20539, Bloemfontein 9300, South Africa Cancer is amongst the three leading causes of death and morbidity. Plants have significant bioactive compounds that combat chronic ailments including cancer. The objective of this study was to determine the anticancer activity of the five methanolic plant extracts from three plants. The Sulforhodamine B (SAB) assay against three cancer cell lines (TK10, UACC62 & MCF7) was used. The study also investigated the antioxidant activity and determined the phytochemical contents of the extracts. Extracts from Scilla sp. had potent activity of IC50 b6.25 μg/ml against all three cell lines. The leaves of Buxus macowanii and the stems of Polygala myrtifolia exhibited moderate activity. The presence of flavonoids, saponins, steroids and alkaloids was determined from the plant extracts and these may account for the anticancer activity. The plants used in this study show potential in the development of anticancer agents. doi:10.1016/j.sajb.2015.03.172
Acacia erioloba (camel thorn) is an indigenous tree species in South Africa. It was declared a protected tree, according to the National Forest Act (84) of 1998 and plays important ecological and economic roles. Death of camel thorn trees in the Kathu area of the Northern Cape Province has been reported since the early 1980s. Speculated causes included the mining activities in the area, environmental changes, pathogens and the age of trees. The aim of this study is to identify possible biotic causal agents of tree die-off, with a focus on pathogenic fungal species, and to investigate the correlation of their distribution with climate, growth conditions, land use practices, mining dust and insect pests. We conducted a pilot survey of the health status of camel thorn trees in the Northern Cape, Free State and Limpopo Provinces. Higher numbers of dying trees were encountered in the Kathu area, compared to the Boshof and Limpopo sites. Symptoms observed on trees included branch flagging, presence of fungal fruiting bodies and insect damage. Fungal species in the Botryosphaeriaceae, Fusarium, Phellinus and Ganodermas.l.were most commonly obtained, while the larvae of cerambycid beetles were often found in dying branches. Further in depth investigation is required to understand the role of these fungi in tree death and the interactions with insects and abiotic factors.
The use, management and distribution of Siphonochilus aethiopicus in the Limpopo Province, South Africa
doi:10.1016/j.sajb.2015.03.174
M.T. Rasethea, M.J. Potgietera, M.F. Pfabb a Department of Biodiversity, University of Limpopo, Private Bag X1106, Sovenga 0727, South Africa b South African National Biodiversity Institute, 2 Cussonia Avenue, Brummeria, Pretoria, South Africa
The antimicrobial activity of commercial essential oils against skin pathogens
Siphonochilus aethiopicus is commonly used as a medicinal plant in South Africa and is currently listed as critically endangered on the South African Red Data list of plants. Information on the use of this species was collected using a semi-structured questionnaire by interviewing 180 traditional healers and 110 community members across the Limpopo Province. The management of the species was documented also by using a semi-structured questionnaire with local traditional leaders and environmental officers from where the species is distributed. Data on the distribution was recorded using a field data sheet provided by South African National Biodiversity Institute. A total of 25 medicinal uses of S. aethiopicus were recorded
A. Van Der Merwe, S.F. Van Vuuren Department of Pharmacy and Pharmacology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown 2193, South Africa Plant essential oils are the most widely used of all natural therapies to date and their use in dermatology independently and in combination has been recorded since antiquity. The aim of this study was to validate/ provide credence to the claimed therapeutic applications of essential oils by evaluating their antimicrobial efficacy against dermatologically relevant pathogens such as, Candida albicans, Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa and Escherichia coli. The antimicrobial activities of 59 essential oils alone and in combination were evaluated using the minimum inhibitory concentration (MIC)