Browsing by Author "Stangeland, Torunn"

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    Antioxidant and anti-plasmodial activity of extracts from three Ugandan medicinal plants
    (Journal of Medicinal Plants Research, 2010) Stangeland, Torunn; Wangensteen, Helle; Katuura, Esther; Lye, Kare A.; Paulsen, Berit S.
    Extracts from three plants; Hallea rubrostipulata, Vernonia adoensis and Zanthoxylum chalybeum, were tested for antioxidant activity using three assays 2,2-Diphenyl-1-picrylhydrazyl (DPPH), Ferric Reducing Ability of Plasma (FRAP) and total phenol content) and anti-plasmodial activity using an Enzyme-Linked Immunosorbent Assay (ELISA) on Plasmodium falciparum chloroquine sensitive strain MRA-285 line. The objective of the study was to find candidates for making anti-malarial phytomedicines. The water extract of H. rubrostipulata showed very high anti-plasmodial activity (IC50= 1.95 μg/ml) and high antioxidant activity as well. Thirteen other extracts had high anti-plasmodial activity ranging from 2.14 to 3.63 μg/ml (chloroquine IC50= 8 μg/ml). We found high correlation between the different antioxidant essays
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    The framework tree species approach to conserve medicinal trees in Uganda
    (Agroforestry systems, 2011) Stangeland, Torunn; Tabuti, John; Lye, Kare A.
    Framework species are indigenous tree species planted in a mixed stand to accelerate natural regeneration of forest and encourage biodiversity regeneration. In this study we used the framework species method to make multipurpose tree gardens to provide traditional healers with woody species used for medicine and other needs like food and firewood. We specifically determined the phenology, germination behaviour, survival and growth after planting 19 indigenous and 8 introduced woody species. The species were planted in a mixed stand together at a density of 3125 ha-1. Field performance was assessed by monitoring survival, height and crown width once every month for 13 months after planting. Eleven species (Artocarpus heterophyllus, Calliandra calothyrsus, Callistemon citrinus, Carica papaya, Carissa spinarum, Leucaena leucocephala, Markhamia lutea, Sarcocephalus latifolius, Senna siamea, S. spectabilis and Terminalia schimperiana) proved to be excellent framework species. Eight species qualified as ‘acceptable’ FWS (Albizia coriaria, Ceiba pentranta, Entada abyssinica, Erythrina abyssinica, Eugenia jambos, Ficus sycomorus, Maesopsis eminii and Milicia excelsa), while seven species were ranked as ‘marginally acceptable’ (Acacia macrothyrsa, Calpurnia aurea, Canarium schweinfurthii, Capparis tomentosa, Ficus natalensis, Senna sp. and Warburgia salutaris). Annona squamosa was the only species rejected since both germination and survival was low. Trees with good reforestation traits could be recommended for planting while the species that were marginally acceptable or rejected require extra research since some of them are important medicinal woody species of conservation concern.
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    The Influence Of Light And Temperature On The Germination Of Two Ugandan Medicinal Trees
    (African Journal of Ecology, 2008) Stangeland, Torunn; Tabuti, John R. S.; Lye, Ka°re A.
    For reasons of the problems of establishment of some Ugandan trees in certain environments, we investigated the influence of temperature and light on germination and seedling growth of two locally threatened medicinal trees, Hallea rubrostipulata and Sarcocephalus latifolius, to facilitate their establishment. Field and controlled laboratory experiments were carried out to investigate the species germination requirements and seedling growth. Both species needed light to germinate. Hallea rubrostipulata had a temperature optimum of 25°C with 79% germination, while for S. latifolius, the total germination after 28 days was close to 60% at temperatures from 20 to 35°C. Seedlings of S. latifolius survived well at 35°C, while those of H. rubrostipulata died at this high temperature. Conversely, seedling of S. latifolius died at the low temperature of 15°C. However, in field experiment S. latifolius failed to germinate in the available degraded environments, probably because of predation and because the soil is not able to retain water long enough to support seedling growth. We, therefore, conclude that in this part of Uganda, nursery assistance is needed to establish healthy populations of Sarcocephalus and many other endangered trees.