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Crude extracts of Dracaena steudneri bark (DSB), Sapium ellipticum bark (SEB) and Capparis erythrocarpos root (CER) were investigated for their antifungal activity in immunocompromised mice infected with Candida albicans in an in vivo mice infection model. Extracts of these plant species are commonly used to treat fungal infections in East African countries. Three groups of white albino mice were immunosuppressed with 200 mg/kg body weight of cyclophosmamide for four consecutive days after which they were administered with 0.3 ml of 0.5 McFarland standard inoculum of C. albicans. The groups were treated with escalating doses of 100, 200 and 400 mg/kg of body weight of dichloromethane extracts. There was substantial dose dependency in all treatments given, with mice survival to the end of the experiment correlating well to the dose levels. At a dose of 400 mg/kg, C. erythrocarpos was the most effective with mice survival of 60% and organ burden clearance ranging from 64.0%–99.9% (P < 0.0001) in all treatments. The results revealed that C. erythrocarpos possessed significant potential for development into antifungal drugs suitable for control of Candida infections. The effectiveness of the plant extracts in vivo was a confirmation of the value of ethnopharmacological leads in drug discovery.

Objective: To evaluate the free radical scavenging ability and antiradical activities of Ximenia caffra fruit extracts in their different ripening stages. Methods: Using standard procedures, Ximenia caffra fruit extracts were determined for ferrous ions chelating ability, nitric oxide and hydroxyl radical scavenging ability. Antiradical activities were assessed using 1,1-diphenyl-2-picrylhydrazyl (DPPH) in which the fruit extracts were evaluated for the number of antiradical units (AU515), the number of antiradical units per 1 mg of extracts (EAU515) and the total number of antiradical units per 1g of raw fruits (TAU515). Results: The fruit extracts exhibited significant higher ferrous ion chelating and free radical scavenging capacity compared to synthetic antioxidants (standard). Fruit extracts in early ripening stage (ERS) exhibited stronger ion chelation, nitric oxide and hydroxyl radical scavenging ability with low effective fruit extract concentration required to reduce free radicals by 50% (EC50) that were 14, 25 and 30µg/ml respectively than the late ripening stage (LRS) extracts. The fruit extracts also showed high AU515, EAU515 and TAU515. The values of AU515 ranged from 0.93 to 0.95, while EAU515 from 78.30 to 79.34 and TAU515 ranged from 19762.46 to 23821.23 of the extracts in LRS and ERS respectively. Conclusion: Based on these observations Ximenia caffra is potentially beneficial to human health due to its strong ability to scavenge free radicals. Its utilization can potentially reduce the risk of degenerative diseases to human beings.

Two new anti-HIV xanthones, 6,7,11-trihydroxy-10-methoxy-9-(7-methoxy-3-methyl-1-oxoisochroman-5-yl)-2-methyl-12-oxo-12H-benzo[b]xanthene-4-carboxylic acid (1) and 6,7-dihydroxy-10,11-dimethoxy-9-(7-methoxy-3-methyl-1-oxoisochroman-5-yl)-2-methyl-12-oxo-12H-benzo[b]xanthene-4-carboxylic acid (2), and a new hexadecahydrochrysen-3-ol (3) were isolated from the tubers of Pyrenacantha kaurabassana. Compounds 1 and 2 showed moderate anti-HIV activity when tested in the deCIPhR assay on HIV virus type NL4-3, with IC₅₀ values of 21 and 2 μg/mL, respectively.

This study was conducted to investigate the potential of predicting alpha diversity and turnover rates of a highly diverse herbivorous insect family (Geometridae) based on vascular plant species richness and vegetation structure.The study was carried out on the south-western slopes of Mount Kilimanjaro within a wide range of habitats between 1200 and 3150 m elevation.The floristic and structural composition of the vegetation was recorded at 48 plots of 400 m(2). Geometrid moths were sampled manually at light sources located at the plot centres. Principal components analysis, redundancy analysis and multiple linear regression were used to explore how alpha diversity and species turnover of geometrid moths are related to vegetation structure and plant species richness.Alpha diversity of geometrid moths was significantly correlated with species diversity patterns in the most common vascular plant families (R-2 = 0.49) and with plant structural parameters (R-2 = 0.22), but not with overall floristic diversity. Species turnover of geometrid moths was strongly linked to diversity changes in a range of plant families (40% explained variance), less strongly to changes in vegetation physiognomy (25%), and only weakly to overall floristic diversity (5%). Changes in elevation were a better predictor of both alpha diversity and species turnover of geometrid moths than any principal component extracted from the vegetation data.Vegetation composition, diversity and structure all showed significant correlations with the diversity and species composition of geometrid moth assemblages. Nevertheless, in most cases relationships were indirect, via environmental parameters such as temperature and humidity, which influenced both vegetation and moth fauna. Possible direct links between geometrid diversity and potential food plants were much weaker. The lack of a significant correlation between overall plant species richness and geometrid diversity indicates that tropical geometrid moths may not be very selective in their food plant choice. Accordingly, a clear correlation between floral diversity and herbivore species richness must be regarded as overly simplistic, and the diversity of vascular plants cannot universally be used as a suitable biodiversity indicator for diverse insect taxa at higher trophic levels.

In contrast to their well-studied counterparts in the Neotropics and in Asia, East African montane rain forests are surrounded by semi-arid savanna plains. These plains have a high erosion potential for salt crusts accumulated at the soil surface. Hence it may be hypothesized that East African montane forest ecosystems experience strongly enhanced nutrient inputs via dry deposition, which alters their overall biogeochemistry. The aim of our study was to test this hypothesis by investigating K, Mg, Ca, Na and N-forms in rainfall, throughfall, fine litter, litter percolate and soil solution of a montane rain forest at Mt. Kilimanjaro. Four forest plots situated at elevations between 2250 and 2350 m asl on the south-western slopes of Mt. Kilimanjaro were studied for 2 y. In contradiction to our hypothesis, inputs of K, Mg, Ca and Na via rainfall (7.5, 0.9, 2.3 and 6.2kg ha−1y−1) and throughfall (35, 2.0, 3.5 and 11kg ha−1−1) were low on Mt. Kilimanjaro. Fluxes of NH4-N and NO3-N were within the range observed at other montane rain forests, with NO3-N being the only nutrient partly absorbed in the forest canopies (2.9kg ha−1y−1 in rainfall, 0.9kg ha−1y−1 in throughfall). The highest overall nutrient concentrations in water samples occurred in litter percolate (1.4mg l−1 K, 0.3mg l−1 Mg, 0.8mg l−1 Ca, 0.3mg l−1 NH4-N, 0.9mg l−1 NO3-N), with values still being low compared to other sites. Nutrient concentrations in seepage water strongly declined with increasing soil depth. Thus, both inputs and losses of base cations from the forest by water pathways are assumed to be low. N or P limitation of growth is not expected since high fluxes of N and P in fine litter (119 and 5.9kg ha−1y−1 for N and P respectively) indicate low within-stand efficiency.

Aim This study investigates diversity patterns of vascular plants and plant-feeding geometrid moths during montane rain forest regeneration in relation to the biogeographical and historical conditions of Mt Kilimanjaro.Location Investigations were undertaken on the south-western slopes of Mt Kilimanjaro at altitudes between 2075 and 2265 m.Methods Thirteen plots were selected for this study. Four of these were situated in the middle of large clearings (> 1000 m(2)), three in secondary forest, two in mature forest remnants surrounded by secondary forest and four plots within continuous closed mature forest. Vascular plant species were recorded in an area of 20 x 20 m(2). Geometrid moths were attracted using lamps placed inside reflective gauze cylinders.Results Ninety-three species of vascular plants were recorded on the plots. Plant diversity increased in the course of forest regeneration from clearings and secondary forest to mature forest remnants and mature forest. This increase was visible in all vegetation strata as well as in the species number of Dicotyledoneae. The diversity of geometrid moths conversely decreased from early to late successional stages. A total of 2276 Geometridae representing 114 morphospecies were included in the study. Local values of Fisher's alpha varied from 10.3 to 18.3 on clearings and in secondary forest, whereas they remained below 8.0 in mature forest and mature forest remnants. There was a significant negative correlation between the diversity of Geometridae and the number of dicots, and of plant species in the shrub layer.Main conclusions Contrary to an expected positive correlation between the diversity of vascular plants and herbivorous geometrid moths, diversity patterns of these two groups are strongly diverging due to biogeographical and ecological factors differently affecting the two groups. The increase in plant diversity can chiefly be explained with an increase in epiphyte diversity which is related to the occurrence of suitable habitats in extensive moss layers on huge Ocotea usambarensis (Engl.) trees in the mature forest. The low diversity of geometrid moths in these forests may be connected to the isolation and relatively young age of the montane rain forests on Mt Kilimanjaro. Hence only a small number of moth species adapted to the cool and perhumid conditions within moist mature forest have so far immigrated into these habitats, and time was insufficient for the evolution of many new species.

Flora, vegetation and seed bank were studied in a dry Afromontane forest in the Kondoa Irangi Hills, Tanzania with the objective to obtain information necessary for the promotion of conservation of this forest, which is rapidly degenerating due to human pressure. A preliminary checklist of 104 vascular plants occurring in the forest is provided. Based on 27 plots, each of 400 m2, the forest had the following ecological features: mean tree density 408 stems · ha−1; basal area 66.56 m2 · ha−1; Shannon and Wiener diversity 2.6406; evenness 0.7585 and species richness 31 tree species per 1.08 ha. The seed bank was dominated by woody species, including mature forest tree species, and had several species in common with the standing vegetation. The forest contains species that are phytogeographically linked to Madagascan, Western and Southern African floras and also species disjunctly distributed in this forest and the Eastern Arc Mountains of Tanzania. Correspondence Analysis of tree species based on size classes showed that the timber species had declining populations, indicating the possibility of genetic erosion, while other species showed expanding or interrupted populations. Some DBH-size classes (e.g. 145.0–189.9 cm) have disappeared from the forest, presumably due to their selective removal. We recommend detailed integrated floristic and faunistic studies of the forest, targeting the ecologically sensitive indicators of habitat change such as orchids, birds, reptiles and amphibians. Finally, a proposal to conserve the forest under a community-based forest conservation scheme is put forward.

A seed rain study in semi-arid central Tanzania was conducted with the objective of providing guidelines on how to rehabilitate the degraded vegetation on the hillslopes of the Kondoa Irangi. The s ...

Use of multi-plant extracts against infectious diseases is increasing in rural Tanzania. The study evaluated this ethnomedicinal practice by using mixed root extracts of Carisa edulis, Ximenia caffra, Harrisonia abyssinica and Euclea natalensis against single extracts of the same plants. Disc diffusion assay and Tube dilution techniques were used to compare bioactivity of plant extracts in-vitro. The ANOVA test indicated significant difference (P0.05) between these extracts types. Multi-plant extracts had inhibition zones of up to 26 mm as compared to 14 mm for single extracts. Minimum Inhibitory Concentration for multi-plant extract was 8.3 microg/ml against 69 microg/ml for single extracts. Multi-plant extracts inhibited all the five test bacterial species while single extracts inhibited three species. Eight out of ten multi-plant extracts (80%) were bactericidal while only two out of four single extracts (50%) were bactericidal. Generally, multi-plant extracts were more superior over single plant extracts and could be developed into more potent antibiotics against resistant pathogens.

© Cambridge University Press 2010. The montane rain forest belt on Mt. Kilimanjaro forms an important water source for northern Tanzania that is threatened by both logging and fire. The aim of this study was to investigate consequences of forest fragmentation on various aspects of the water cycle. Soil properties, rainfall, throughfall, and soil water suction were analyzed for mature forest, secondary forest patches, and large clearings. A total of 10 plots located on the south-western slopes of the mountain between 2100 and 2300 m.a.s.l. were monitored from May 2000 until June 2002. Annual rainfall amounts ranged from 2000–2600 mm and showed high spatial and inter-annual variability. Rainfall interception ranged from 3% to 9% of incident rainfall in clearings to a maximum of 32% in forests. In general, soils under mature forest were wettest and showed only minor moisture fluctuations through the year. Soils of secondary forest sites were driest and soil water suction exhibited the largest fluctuations. The difference between the two forest types may reflect a combination of differences in interception, evaporation from the forest floor, and transpiration, because ventilation and radiation penetration can be expected to be enhanced in fragmented secondary forest. In clearings the higher throughfall and presumably lower transpiration rates led to moister conditions compared to adjacent secondary forest sites. Top-soil sand contents of the Andisols differed between sites, with disturbed sites having higher sand contents and consequently lower water contents at similar soil water suctions than did mature forest sites. […].

Fungal infections represent a significant cause of morbidity and mortality especially in immunocompromised patients in the world today. Dichloromethane (DM) and aqueous (W) extracts of nine plants used traditionally for the treatment of fungal infections in Bukoba rural district in Tanzania were screened for antifungal activity against Candida albicans, Cryptococcus neoformans, and Aspergillus niger using agar well and disk diffusion methods. Dichloromethane extracts of Capparis erythrocorpos [CE] Isert (Capparaceae), Cussonia arborea [CA] Hochst. Ex A. Rich (Araliaceae), Drocaena steudneri [DS] Engl. (Dracaenaceae), Lannea schimperi [LS] (A. Rich) Engl. (Anacardiaceae), Rouvolfia vomitoria [RV] Afz (Apocynaceae), and Sapium ellipticum [SE] (Krauss) Pax (Euphorbiaceae) showed activity against all three fungi. Extracts of Rumex usambarensis [RU] (Dammer) Dammer (Polygonaceae) and Zehneria scabro [ZS] (L.f.) Sond. (Cucurbitaceae) had an activity limited to only one or two of the test organisms. Rhoicissus tridentata [RT] (L.Q Wild & Drum (Vitaceae) was the only plant without activity. Fractions of the active extracts CE, CA, DS, LS, and SE exhibited higher antifungal activity against one or more of the three fungi. Four compounds isolated from S. ellipticum also exhibited antifungal activity against one or more of the three fungi. The minimum inhibitory concentrations (MICs) and minimum fungicidal concentrations (MFCs), determined using the microplate assay method, ranged between 0.4 and 50.0 mu g/mL for crude extracts, 1.6 and 50.0 mu g/mL for semi-purified fractions, and 0.12 and 1.0 mu g/mL for pure compounds, as compared to 0.016-1.5 mu g/mL for fluconazole. We confirm the potential of traditionally used plants as a source of new drugs for treatment of fungal infections.

Background Ethnobotanical surveys were carried out to document herbal remedies used in the management of HIV/AIDS opportunistic infections in Bukoba Rural district, Tanzania. The district is currently an epicenter of HIV/AIDS and although over 90% of the population in the district relies on traditional medicines to manage the disease, this knowledge is impressionistic and not well documented. The HIV/AIDS opportunistic conditions considered during the study were Tuberculosis (TB), Herpes zoster (Shingles), Herpes simplex (Genital herpes), Oral candidiasis and Cryptococcal meningitis. Other symptomatic but undefined conditions considered were skin rashes and chronic diarrhea. Methods An open-ended semi-structured questionnaire was used in collecting field information. Descriptive statistics were used to analyze the ethnobotanical data collected. Factor of informant consensus (Fic) was used to analyze the ethnobotanical importance of the plants. Results In the present study, 75 plant species belonging to 66 genera and 41 families were found to be used to treat one or more HIV/AIDS related infections in the district. The study revealed that TB and oral candidiasis were the most common manifestations of HIV/AIDS opportunistic infections affecting most of the population in the area. It unveils the first detailed account of ethnomedical documentation of plants focusing the management of HIV/AIDS related infections in the district. Conclusion It is concluded that the ethnopharmacological information reported forms a basis for further research to identify and isolate bioactive constituents that can be developed to drugs for the management of the HIV/AIDS opportunistic infections.

The effect of kadosero , a crude mineral used by traditional healers as a supplement to plant extracts against microbial infections was evaluated. A sample of kadosero from a local market was both analyzed for its basic composition and its role on bioactivity of plant extract. Titrimetric, Gravimetric and Atomic Absorption Spectrometric analyses were used to determine contents of the mineral kadosero . Disc Diffusion Assay was used for bioactivity screening in-vitro. Chemical analysis of kadosero revealed the presence of (0.0038mg/g), Fe2 (0.0027mg/g), Cl- (232.683mg/g) and Na+ (151.25mg/g). In-vitro tests revealed that supplementing extract of Balanites aegyptiaca with a mineral kadosero by using untreated well water reduced number of bacterial from 100 colony forming units to nil at a mass of a mineral between 60-100 mg. On the other hand, a mineral kadosero did not increase bioactivity of the extract of B. aegyptiaca against the test microbes in agar disc diffusion assay. This was attributed by interaction between the mineral kadosero and nutrient agar medium. The crude mineral kadosero can be supplemented to other plant extracts used locally for treatment of general bacterial infections for increased bioactivity. Further study is recommended to determine mechanisms for bacterial vulnerability to this mineral supplement. Keywords : mineral supplement; plant extract; traditional healers The African Journal of Traditional, Complementary and Alternative Medicines Vol. 4 (1) 2007: pp. 1-6

Plants used in traditional medicine in Bukoba Rural district in Tanzania were evaluated for their in vitro antimicrobial activities. Plant materials from eight plant species (Harungana madagascariensis (Lam) Poir., Jatropha curcas L., Lantana trifolia L., Plectranthus barbatus Andr., Pseudospondias microcarpa Engl., Psorospermum febrifugum Spach, Teclea nobilis Del. and Vernonia adoensis [Warp.] SL) were collected based on ethnomedical information provided by traditional herbal practitioners. Results of the study indicate that extracts from the eight plant species were active against at least one or more of the test organisms (Bacillus subtilis, Staphylococcus aureus [gram positive], Escherichia coli, Pseudomonas aeruginosa [gram negative] and Candida albicans [Yeast]). A profile of secondary metabolites (alkaloids, terpenoids, triterpenes, phenolics, tannins, flavonoids, anthraquinones, flavonols/flavones and /or chalcones, sterols and saponins) was obtained for three plant species (Jatropha curcas L., Plectranthus barbatus Andr., and Pseudospondias microcarpa Engl.). The paper discusses the probable therapeutic basis of these traditional plants based on their secondary metabolite profiles and for the first time draws research attention to Bukoba Rural district as a source for plants with potential pharmaceutical applications.