Browsing by Author "Kasenene, John M."

Now showing 1 - 5 of 5
  • Thumbnail Image
    Item
    Cycloartane triterpenes from the leaves of Neoboutonia macrocalyx L.
    (Elsevier, 2014) Namukobe, Jane; Kiremire, Bernard T.; Byamukama, Robert; Kasenene, John M.; Dumontet, Vincent; Guéritte, Françoise; Krief, Sabrina; Florent, Isabelle; Kabasa, John D
    Neoboutonia macrocalyx is used by people in south western Uganda around Kibale National Park in the treatment of malaria. Phytochemical investigation on the leaves of this plant led to the isolation of nine cycloartane triterpenes (1–9) and one phenanthrene; 7-methoxy-2,8 dimethyl-9, 10-dihydrophenantherene-3,6 diol (10) along with three known compounds which included 22-de-Oacetyl- 26-deoxyneoboutomellerone (11), mellerin B (12) and 6-hydroxystigmast-4-en-3-one (13). The chemical structures of the compounds were established mainly through a combination of spectroscopic techniques. The isolated compounds were evaluated for antiplasmodial activity against the chloroquine-resistant FcB1/Colombia strain of Plasmodium falciparum and for cytotoxicity against the KB (nasopharyngeal epidermoid carcinoma) and MRC-5 (human diploid embryonic lung) cells. Seven out of 13 compounds exhibited good antiplasmodial activity with IC50 of 65 lg/ml with two compounds exhibiting low cytotoxicity and five compounds having significant cytotoxicity.
  • Thumbnail Image
    Item
    Elephants, Selective Logging and Forest Regeneration in the Kibale Forest, Uganda
    (Journal of Tropical Ecology, 1996) Struhsaker, Thomas T.; Lwanga, Jeremiah S.; Kasenene, John M.
    The Kibale Forest, western Uganda, is the only site where studies have compared the impact of elephants on rainforest regeneration in logged and unlogged control areas. Elephants used heavily logged areas more than lightly logged and unlogged areas. Forest gaps were used more by elephants than closed-canopy areas and large gaps more than small ones. Gaps were larger in logged than unlogged forest. There were lower densities of young trees (saplings and poles) and a higher incidence of elephant damage to them in heavily logged forest than in lightly logged and unlogged sites. Elephant use of an area and damage to young trees was inversely or unrelated to the density of young trees and directly related to the density of herbaceous tangle. Heavy logging resulted in large areas of herbaceous tangle, which attracted elephants who suppressed forest regeneration by damaging young trees and perpetuating the herbaceous tangle. The tangle directly competed with regeneration of young trees while also attracting elephants and rodents (seed and seedling predators) and facilitating increased windthrow of trees. Selective browsing of young trees by elephants affected rates of regeneration, growth form and species composition. Rather than remove elephants, a more effective and humane approach to long-term management of logging is to reduce logging offtake and incidental damage caused by timber extraction.
  • Thumbnail Image
    Item
    Plants For Malaria Treatment in Southern Uganda: Traditional Use, Preference and Ecological Viability
    (Journal of Ethnobiology, 2007) Ssegawa, Paul; Kasenene, John M.
    A study on ethno medicinal use, preference for species, and ecological viability of plants used for treating malaria was carried out among the communities living around the Sango Bay Forest Reserve in southern Uganda. Semi-structured interviews and informal discussions were used to collect ethno botanical information. Abundance and demographic patterns of the key forest tree species used to treat malaria were determined, using 45 plots of 0.1 ha. Sixteen species representing 11 families and 14 genera were reportedly used to treat malaria, including four new reports. Hallea rubrostipulata (K. Schum.) J.-F.Leroy, Warburgia ugandensis Sprague, and Syzygium guineense (Willd.) DC. were the most important forest tree species used to treat malaria and were chosen for further study. The three species were found to be highly valued in the treatment of malaria and similarly used by the local people as determined by the clustering procedure. The species generally had an inverse J-shaped curve in their population structures, indicating viable regenerating populations. The recognition of the use of traditional medicine by the local communities as an integral and essential part of their health care system is vital in the conservation and sustainable utilization of these plants.
  • Thumbnail Image
    Item
    Regeneration of an afromontane forest Following agricultural encroachment in Southwestern Uganda
    (Israel Journal Of Plant Sciences, 2000) Lejju, Julius Bunny; Oryem-Origa, Hannington; Kasenene, John M.
    A study of the regeneration of an Afromontane forest was carried out in Mgahinga Gorilla National Park (MGNP), southwestern Uganda, following agricultural encroachment in the last 50 years. The landscape was changed by terracing and removing the indigenous vegetation and replacing it with exotic tree species. This study also examined the soil nutrient status of the formerly encroached area in the park. Species richness of indigenous trees was high in the formerly cultivated area. Twenty-six indigenous species were found in the formerly cultivated area, compared with 20 species in the natural forest and 12 species of indigenous trees found under exotic woodlots. There was a significant difference in species richness and density in the three habitat types. The natural forest supported the highest stem density (75%), and the lowest stem density (4%) was recorded under exotic woodlots. Seedlings (<2 cm diameter at breast height) accounted for the majority of juveniles in the three habitats. The natural forest had the highest density (24,625 seedlings/ha), and exotic woodlots supported the lowest stem density (1,350 seedlings/ha).
  • Thumbnail Image
    Item
    Regeneration of indigenous trees in Mgahinga Gorilla National Park, Uganda
    (African Journal of Ecology, 2001) Lejju, Julius B.; Oryem-Origa, Hannington; Kasenene, John M.
    This study examines the regeneration of indigenous tree species in the formerly encroached area in Mgahinga Gorilla National Park (MGNP), south-western Uganda. Before gazetting in 1992, MGNP had basically been agricultural land for well over 50 years. The distribution of exotic vegetationwas established using a Geo- graphical Positioning System receiver and indigenous vegetation was sampled by establishment of quadrats along transect lines.