A Review of the Toxicity and Phytochemistry of Medicinal Plant Species Used by Herbalists in Treating People Living With HIV/AIDS in Uganda

Introduction: Despite concerns about toxicity, potentially harmful effects and herb-drug interactions, the use of herbal medicines remains widely practiced by people living with HIV/AIDS (PLHIV) in Uganda. Objective: The objective of the paper was to comprehensively review the literature on the toxicity and chemical composition of commonly used medicinal plant species in treating PLHIV in Uganda. Methods: We reviewed relevant articles and books published over the last sixty years on ethnobotany, antiviral/anti-HIV activity, toxicity, phytochemistry of Vachellia hockii, Albizia coriaria, Bridelia micrantha, Cryptolepis sanguinolenta, Erythrina abyssinica, Gardenia ternifolia, Gymnosporia senegalensis, Psorospermum febrifugium, Securidaca longipendunculata, Warburgia ugandensis and Zanthoxylum chalybeum and their synonyms. We searched PubMed, Web of Science, Scopus, Science Direct and Google Scholar. Discussion: Most of the plant species reviewed apart from P. febrifugium, S. longipedunculata and C. sanguinolenta lacked detailed phytochemical analyses as well as the quantification and characterization of their constituents. Crude plant extracts were the most commonly used. However, purified/single component extracts from different plant parts were also used in some studies. The U87 human glioblastoma was the most commonly used cell line. Water, ethanol, methanol and DMSO were the commonest solvents used. In some instances, isolated purified compounds/extracts such as Cryptolepine and Psorospermin were used. Conclusion: Cytotoxicity varied with cell type, solvent and extract type used making it difficult for direct comparison of the plant species. Five of the eleven plant species namely, A. coriaria, C. sanguinolenta, G. ternifolia, P. febrifugium and Z. chalybeum had no cytotoxicity studies in animal models. For the remaining six plant species, the crude aqueous and ethanol extracts were mainly used in acute oral toxicity studies in mice. Herbalists reported only A. coriaria and W. ugandensis to cause toxic side effects in humans. However, selective cytotoxic plant extracts can potentially be beneficial as anticancer or anti-tumour drugs

Nutritional value of selected wild edible plants in Teso-Karamoja Region, Uganda

The use of wild plants for food in the rural communities of Uganda is widespread. This is attributed to food scarcity, perceived nutritional value,  medicinal and health benefits and cultural preservation. However, the claims on the nutritional value of some wild edible plant species have not  been fully validated. In cognizance of this, the macroelement, beta-carotene and ascorbic acid profile of five wild plants commonly used for food in and around eight forest reserves of Teso-Karamoja region, Uganda, were analysed. The plants prioritized for analysis were Vigna kirkii (Baker) J.B. Gillett, Maerua angolensis D.C., Leptadenia hastata (Schumach. & Thonn.) Decne, Senna obtusifolia (L.) H.S. Irwin & Barneby and Dioscorea sp.). The  macro-element, ascorbic acid and beta-carotene composition of these plants was analyzed in triplicate. The variance in parameter means was  analysed using one-way Analysis of Variance in SPSS ver. 16.0. The results showed that all the means of species were significantly different at the p=0.05 level. The highest macro-nutrient means were 80.74±0.34 %/100 g moisture content in V. kirkii, 3.95±0.23 g/100 g ash content in M.  angolensis, 19.04±0.37 Kcal gross energy in M. angolensis, 27.93±0.85 g/100 g dietary fibre in L. hastata, 3.40±0.13 g/100 g crude fat in L. hastata, 65.43±2.91 g/100 g carbohydrate in Dioscorea sp., 36.37±0.42 g/100 g crude protein in M. angolensis. The highest ascorbic acid mean was 14.71±3.56 mg/100 g in M. angolensis while beta-carotene was 1082.1±0.08 μg/100 g in S. obtusifolia. These results show that these wild edible plants have a significantly variable nutritional value. Some of the macro elements can sufficiently meet the Recommended Daily Allowance (RDA) and Adequate Intakes (AI) for certain life stages and groups if consumed in ideal quantities. This information is vital in enhancing food and nutrition security awareness in the community and uplifting the social appeal and acceptability of these plants. This can be enhanced by investigating the micro-nutrients of public health significance, anti-nutrient factors, and toxic compounds in these plants. Key words: Nutritional value, wild edible plants, macro-nutrient, ascorbic acid, betacarotene,Teso-Karamoja, Ugand

Farmland biodiversity and agricultural management on 237 farms in 13 European and two African regions

Farmland is a major land cover type in Europe and Africa and provides habitat for numerous species. The severe decline in farmland biodiversity of the last decades has been attributed to changes in farming practices, and organic and low-input farming are assumed to mitigate detrimental effects of agricultural intensification on biodiversity. Since the farm enterprise is the primary unit of agricultural decision making, management-related effects at the field scale need to be assessed at the farm level. Therefore, in this study, data were collected on habitat characteristics, vascular plant, earthworm, spider, and bee communities and on the corresponding agricultural management in 237 farms in 13 European and two African regions. In 15 environmental and agricultural homogeneous regions, 6–20 farms with the same farm type (e.g., arable crops, grassland, or specific permanent crops) were selected. If available, an equal number of organic and non-organic farms were randomly selected. Alternatively, farms were sampled along a gradient of management intensity. For all selected farms, the entire farmed area was mapped, which resulted in total in the mapping of 11 338 units attributed to 194 standardized habitat types, provided together with additional descriptors. On each farm, one site per available habitat type was randomly selected for species diversity investigations. Species were sampled on 2115 sites and identified to the species level by expert taxonomists. Species lists and abundance estimates are provided for each site and sampling date (one date for plants and earthworms, three dates for spiders and bees). In addition, farmers provided information about their management practices in face-to-face interviews following a standardized questionnaire. Farm management indicators for each farm are available (e.g., nitrogen input, pesticide applications, or energy input). Analyses revealed a positive effect of unproductive areas and a negative effect of intensive management on biodiversity. Communities of the four taxonomic groups strongly differed in their response to habitat characteristics, agricultural management, and regional circumstances. The data has potential for further insights into interactions of farmland biodiversity and agricultural management at site, farm, and regional scale

Application of algae in biomonitoring and phytoextraction of heavy metals contamination in urban stream water

Biological technologies for wastewater remediation techniques employed to remove contaminants in urban stream water are increasingly receiving attention worldwide. The purpose of this study was therefore to determine the concentrations of lead, cadmium, copper, zinc, manganese and iron in algal biomass and establish the feasibility of using algae in phytoextraction and bio-monitoring of environmental quality. Analysis of algal biomass samples in the Nakivubo urban stream ecosystem, Kampala, Uganda, showed that there was contamination by lead, cadmium, copper and zinc as indicated by enrichment factor and pollution load index values. It is suspected that industrial and vehicular emissions are the major sources of these pollutants. Calculated bio-concentration factor was = 1000 but with low concentration thresholds in each element, suggesting that algal biomass was a very good heavy metal accumulator. The bio-concentration values in algal biomass were found to be in the order of copper > zinc > lead > cadmium in the Nakivubo Channelized stream. In conclusion, algae can be a promising aquatic bio-filter plant for phytoextraction and bio-monitoring of polluted urban stream ecosystems and wastewater

Scientific Basis For Banana Cultivar Proportions On-Farm In East Africa

Banana ( Musa spp.) production and diversity in the East African region, has been on the decline for the last 20 years due to both a biotic and biotic problems. There has been an ecological and socio-economic imbalance in the East African Highland banana (Musa AAA-EA) growing systems due to this decline. However, farmers have been growing these bananas in cultivar mixtures, a practice which ensures the continuous sustainability of the system. Cultivar mixtures, however, seem to be in specific proportions based on the strength and weakness of each cultivar and so affecting the clone sets to which cultivars belong, as well as providing predictions on the conservation status of each clone set. The primary objective of the study was to account for the farmers' perceptions behind cultivar proportions and to understand the scientific basis of these proportions in selected sites in East Africa. The study was carried out in Karagwe, Bushenyi and Masaka districts in East Africa, a region considered to be a secondary centre of diversity for bananas. Thirty farms were sampled in one selected parish/ ward in the three sites for ecological data. The quadrat method was used to record abundances of identified cultivars in order to determine the cultivar proportions. Ethno-botanical data collected on traditional knowledge was analysed for twenty-three identified traditional cultivar-selection criteria used in the participatory rural appraisal (PRA), as well as interviews from 15 key informants of each study area. A total of 105 cultivars were identified, 76% of which were the East African Highland bananas. Although fourteen cultivars were common to the three sites, Masaka had the highest proportion with Nfuuka cultivar leading the five clone sets. Cultivar diversity indices explained the proportions in terms of richness and evenness and Nfuuka was the richest clone set. Although all clone sets were represented at each site, they were not evenly distributed; a factor which is disadvantageous in the conservation status of the crop. While results indicated that the agro-ecological and traditional utilisation criteria formed the basis for cultivar proportions on farm for both Karagwe and Masaka, farmers were found to do so because of the high traditional values attached to the crop. However, knowing cultivar proportions in terms of richness and evenness can assist in predicting the stability or change in diversity of banana growing sites.La production et la diversité de la banane ( Musa spp) dans cette région, a été sur le déclin pour le dernier 20 ans en raison des problèmes biotiques. Il y a eu un déséquilibre écologique et socio-économique dans la région montagneuse Africaine del 'Est (banane de montagne, Musa AAA-pièce) des systèmes de croissance en raison de ce déclin. Cependant, les agriculteurs ont grandi ces bananes dans les cultivars associés, une pratique qui garantit la durabilité continue du système d'association de cultivar, cependant, semble être dans les proportions spécifiques fondées sur la resistance et la faiblesse de chaque cultivar et affectant si les séries clones semblables aux lesquelles les cultivars appartiennent, de même que fournir les prédictions sur le statut de conservation de chaque série absolument semblable. L'objectif primaire de l'étude était de représenter les agriculteurs les perceptions derrière les proportions de cultivar et comprendre la base scientifique de ces proportions dans les sites choisis en Afrique de l'Est. L'étude a été exécuté dans Karagwe, les quartiers de Bushenyi et Masaka dans l'Afrique de l'est, une région considérée être un centre secondaire de diversité pour les bananes. Trente fermes ont été echantillonné dans une localité/section choisie dans les trois sites pour les données écologiques. La méthode de quadrat a été utilisée pour enregistrer des abondances de cultivars identifiés pour déterminer les proportions de cultivar. Les données Ethno-botaniques recueillies sur la connaissance traditionnelle ont été analysées pour vingt-trois critères de sélection traditionnelle de cultivar identifiés utilisés dans l'estimation rurale participative (PRA), de même que les entretiens de 15 informateurs clés de chaque secteur d'étude. Un total de 105 cultivars a été identifié, 76% dont étaient les bananes de montagne de l'Afrique de l'Est. Bien que quatorze cultivars étaient communs aux trois sites, Masaka a eu la plus haute proportion de cultivar de Nfuuka menant les cinq séries des clones. Les index de diversité de cultivar ont expliqué les proportions sur le plan de la richesse et de l'égalité et Nfuuka était la série de clone la plus riche. Bien que toutes séries de clones aient été représentées à chaque site, ils n'ont pas été également distribués ; un facteur qui est défavorable dans le statut de conservation de la récolte. Pendant que les résultats ont indiqué que les critères d'utilisation agro-écologiques et traditionnels ont formé la base pour les proportions de cultivar sur la ferme pour Karagwe et Masaka, les agriculteurs ont été trouvés entrain de beaucoups travailler à cause des hautes valeurs traditionnelles attachées à la récolte. Cependant, sachant les proportions de cultivar sur le plan de la richesse et de l'égalité peuvent aider à prédire la stabilité ou le changement dans la diversité de croissance de banane dans les sites

Assessment of heavy metal pollution in the urban stream sediments and its tributaries

Globally, aquatic ecosystems are highly polluted with heavy metals arising from anthropogenic and terrigenous sources. The objective of this study was to investigate the pollution of stream sediments and possible sources of pollutants in Nakivubo Channel Kampala, Uganda. Stream sediments were collected and analysed for heavy metal concentration using flame atomic absorption spectrophotometer. The degree of pollution in Nakivubo channelized stream sediments for lead, cadmium, copper, zinc, manganese and iron was assessed using enrichment factor, geoaccumulation index and pollution load index. The results indicated that (1) the sediments have been polluted with lead, cadmium and zinc and have high anthropogenic influences; (2) the calculation of geo-accumulation index suggest that Nakivubo stream sediments have background concentration for copper, manganese and Fe (Igeo ≤ 0); (3) factor analysis results reveal three sources of pollutants as explained by three factors (75.0 %); (i) mixed origin or retention phenomena of industrial and vehicular emissions; (ii) terrigenous and (iii) dual origin of zinc (vehicular and industrial). In conclusion, the co-precipitation (inclusion, occlusion and adsorption) of lead, cadmium and zinc with manganese and iron hydroxides, scavenging ability of other metals, very low dissolved oxygen and slightly acidic to slightly alkaline pH in stream water could account for the active accumulation of heavy metals in Nakivubo stream sediments. These phenomena may pose a risk of secondary water pollution under sediment disturbance and/or changes in the geo-chemistry of sediments

Heavy metal assessment and water quality values in urban stream and rain water

Water quality monitoring in developing countries is inadequate, especially in stream water affected by urban effluents and runoff. The purpose of this study was to investigate heavy metal contaminants in the Nakivubo Stream water in Kampala, Uganda. Water samples Nakivubo Channelized Stream, tributaries and industrial effluents that drain into the stream were collected and analysed for the total elemental concentration using flame atomic absorption spectrophotometer. The results showed that: 1) the wastewater was highly enriched with lead and manganese above the maximum permissible limit; 2) the levels of dissolved oxygen were below the maximum permissible limit, while the biological oxygen demand was above the maximum permissible limit. All industrial effluents/wastewater were classified as strong (> 220 mg/L). Factor analysis results reveal two sources of pollutants; 1) mixed origin or chemical phenomena of industrial and vehicular emissions and 2) multiple origin of lead (vehicular, commercial establishment and industrial). In conclusion, Nakivubo Channelized Stream water is not enriched with heavy metals. These heavy metals (lead, cadmium and zinc) were rapidly removed by co-precipitation with manganese and iron hydroxides and total dissolved solids into stream sediments. This phenomena is controlled by pH in water