49 research outputs found

    Mosquito Larvicidal Constituents from Lantana Viburnoides SP Viburnoides Var Kisi (A. rich) Verdc (Verbenaceae).

    Get PDF
    \ud \ud Lantana viburnoides sp viburnoides var kisi is used in Tanzania ethnobotanically to repel mosquitoes as well as in traditional medicine for stomach ache relief. Bioassay-guided fractionation and subtraction bioassays of the dichloromethane extract of the root barks were carried out in order to identify the bioactive components for controlling Anopheles gambiae s.s. mosquito larvae. Twenty late III or early IV instar larvae of An. gambiae s.s. were exposed to various concentrations of the plant extracts, fractions, blends and pure compounds, and were assayed in the laboratory by using the protocol of WHO 1996. Mean mortalities were compared using Dunnett's test (p < 0.05) and lethal concentration calculated by Lackfit Inversel of the SAS programme. The crude extract (LC50 = 7.70 ppm in 72 h) and fractions exhibited different level of mosquito larvicidal activity with subtraction of some fractions resulting in activity enhancement. The active fractions contained furanonaphthaquinones regio-isomers (LC50 = 5.48-5.70 ppm in 72 h) and the lantadene triterpenoid camaric acid (LC50 = 6.19 ppm in 72 h) as active principles while the lupane triterpenoid betulinic acid (LC50 < 10 ppm in 72 h) was obtained from the least active fraction. Crude extracts and some fractions had higher or comparable larvicidal activity to the pure compounds. These results demonstrate that L. viburnoides sp viburnoides var kisi extracts may serve as larvicides for managing various mosquito habitats even in their semi-purified form. The isolated compounds can be used as distinct markers in the active extracts or plant materials belonging to the genus Lantana

    Mapping Nairobi's dairy food system: An essential analysis for policy, industry and research

    Get PDF
    Demand for dairy products in sub-Saharan Africa, is expected to triple by 2050, while limited increase in supply is predicted. This poses significant food security risk to low income households. Understanding how the dairy food system operates is essential to identify mitigation measures to food insecurity impact. This study aims to determine the structure and functionality of Nairobi's dairy system using a value chain mapping approach

    In vitro and in vivo anti-trypanosomal activities of methanol extract of Azadirachta indica stem-bark

    Get PDF
    Background: Current chemotherapeutic agents for the treatment of African trypanosomiasis have become largely ineffective, necessitating the search for alternative compounds. The objective of this study was to evaluate in vitro anti-trypanosomal activities of methanol extracts of parts of Azadirachta indica against Trypanosoma brucei rhodesiense, Trypanosoma brucei brucei and Trypanosoma evansi and establish the in vivo efficacy of the most active extract.Materials and methods: Maceration of powdered leaves, stem bark and root bark of the plant in methanol afforded three extracts. In vitro assays were carried out with the extracts on the three trypanosome strains in 96-well microtitre plates at concentration ranges of 4000 - 1000μg/ml. The most active extract was assayed in vivo using Trypanosoma brucei rhodesiense infected Swiss albino mice at doses of 100, 200 and 400 mg/kg body weight. Melarsoprol and suramin served as positive controls. The infected untreated group served as the negative control. Parasitaemia levels, packed cell volume, body weight changes and mean survival period of all groups were monitored throughout the experimental period.Results: Methanol extract of the stem bark of A.indica was most active in vitro against all the three trypanosome strains (MIC values of 9.93±1.88, 16.25±0.92 and 9.97±0.44μg/ml for T. b. rhodesiense, T. b. brucei and T. evansi, respectively). The extract showed optimum activity at 400 mg/kg and was comparable to the positive control groups. Parasitaemia levels were kept at a significantly low level (p &lt; 0.05) by the extract compared to the negative control. Notably, there was no significant difference (p&gt;0.05) in mean survival time of mice treated with the extract at 400 mg/kg and the positive controls.Conclusion: In vitro and in vivo anti-trypanosomal activities of the methanol extract of A. indica stem bark could be attributed to the presence of constituents of moderate polarity.Keywords: Anti-trypanosomal activity, Azadirachta indica, Trypanosoma brucei brucei, Trypanosoma brucei rhodesiense, Trypanosoma evans

    Influence of Soil and Rain on the Levels of Inorganic Anions in Amaranth Leaves from Selected Parts of Kenya

    Get PDF
    The aim of this work was to determine the level of inorganic anions (NO3-, Cl-, SO42-, PO43-, F- and I-) in the leaves of two species of amaranth (Amaranthus hypochondriacus and Amaranthus cruentus) planted in Kenya. The mean levels of inorganic anions, nitrate (NO3-), chloride (Cl-), sulphate (SO42-), phosphate (PO43-), fluoride (F-) and iodide (I-), in the soil from four study regions (Kenyatta University (KU), Bureti, Kisii and Elgon) of Kenya were quantitatively determined. The levels were determined using spectrophotometric, potentiometric and titrimetric methods. The mean levels of  Cl-, SO42-, PO43-, NO3-, F- and I- in soils ranged from 1146.54 to 2733.31 mg/100 g, 1821.60 to 2185.33 mg/100 g, 828.54 to 1111.36 mg/100 g, 1015.55 to 1910.66 mg/100 g, 66.95 to 79.77 mg/100 g and  8.00 to 12.57 mg/kg respectively. The levels of most anions in leaves of A. hypochondriacus and A. cruentus were not significantly different. The means levels of the anions in leaves of the two species indicated that Cl- ion had range of 503.74 to 673.81 mg/100 g, SO42- 701.61 to 955.17 mg/100 g, PO43 532.36 to 629.46 mg/100 g, NO3- 495.79 to 880.99 mg/100 g, F- 7.22 to 9.67 mg/100 g while I- ranged from 2.54 mg/kg to 5.26 mg/kg dry weight. The levels of all inorganic anions determined were found to be within the allowed daily intake (ADI) values. Based on the results of this study, it is recommended that leaves and grains from both species of amaranthus grown in most regions in Kenya may be consumed for nutritional requirements. The consumption of between 250 g and 300 g of fresh amaranthus leaves is sufficient to provide the required daily intake of all the anions considered in this study for all healthy individuals. Keywords: Amaranth, Anions, Amaranthus, Tonui

    Antimicrobial and phytochemical investigation of herbal suspensions used in management of oral health in Nairobi County, Kenya

    Get PDF
    An increasing number of Kenyans are using natural herbal products for general and oral health care due to high cost of conventional medicine. Few of these products, however, have undergone rigorous testing, as evidenced by the limited amount of information on their safety and efficacy in the literature. This study investigated the antimicrobial and phytochemical properties of 10 suspensions based on herbal products sold in Nairobi Kenya. Phytochemical evaluation was carried out using standard methods while agar well diffusion was used to study antimicrobial work.  Results reveal lack of detectable levels of phytochemicals while 50% of the investigated products lacked antimicrobial activity against test bacteria (Staphyloccus aureus ATCC 25923, Pseudomonas aeruginosa (P.a) ATCC 27853, Proteus vulgaris ATCC 6380, Bacillus subtilis ATCC 14579, Candida albicans ATCC 10231, Esherichia coli ATCC 25922, Streptococcus mutans, Enterococcus faecalis, ATCC 9790 and Lactobacillus acidophilus). The study concludes that some products in the market may not be based on herbs as indicated in the label. Thorough investigation of antimicrobial, phytochemical work as well as toxicity should be carried out on such products. The results provide practitioners and consumers with insight into the claims of natural herbal products antimicrobial effects. Key words: antimicrobial activity, herbal products, activity index, phytochemica

    IN VITRO AND IN VIVO ANTI-TRYPANOSOMAL ACTIVITIES OF METHANOL EXTRACT OF AZADIRACHTA INDICA STEM-BARK

    Get PDF
    Background: Current chemotherapeutic agents for the treatment of African trypanosomiasis have become largely ineffective, necessitating the search for alternative compounds. The objective of this study was to evaluate in vitro anti-trypanosomal activities of methanol extracts of parts of Azadirachta indica against Trypanosoma brucei rhodesiense, Trypanosoma brucei brucei and Trypanosoma evansi and establish the in vivo efficacy of the most active extract. Materials and methods: Maceration of powdered leaves, stem bark and root bark of the plant in methanol afforded three extracts. In vitro assays were carried out with the extracts on the three trypanosome strains in 96-well microtitre plates at concentration ranges of 4000 - 1000μg/ml. The most active extract was assayed in vivo using Trypanosoma brucei rhodesiense infected Swiss albino mice at doses of 100, 200 and 400 mg/kg body weight. Melarsoprol and suramin served as positive controls. The infected untreated group served as the negative control. Parasitaemia levels, packed cell volume, body weight changes and mean survival period of all groups were monitored throughout the experimental period. Results: Methanol extract of the stem bark of A.indica was most active in vitro against all the three trypanosome strains (MIC values of 9.93±1.88, 16.25±0.92 and 9.97±0.44μg/ml for T. b. rhodesiense, T. b. brucei and T. evansi, respectively). The extract showed optimum activity at 400 mg/kg and was comparable to the positive control groups. Parasitaemia levels were kept at a significantly low level (p 0.05) in mean survival time of mice treated with the extract at 400 mg/kg and the positive controls. Conclusion: In vitro and in vivo anti-trypanosomal activities of the methanol extract of A. indica stem bark could be attributed to the presence of constituents of moderate polarity

    Constituents of the Essential Oil of Suregada zanzibariensis Leaves are Repellent to the Mosquito, Anopheles gambiae s.s.

    Get PDF
    In traditional African communities, repellent volatiles from certain plants generated by direct burning or by thermal expulsion have played an important role in protecting households against vectors of malaria and other diseases. Previous research on volatile constituents of plants has shown that some are good sources of potent mosquito repellents. In this bioprospecting initiative, the essential oil of leaves of the tree, Suregada zanzibariensis Verdc. (Angiospermae: Euphobiaceae) was tested against the mosquito, Anopheles gambiae s.s. Giles (Diptera: Culicidae) and found to be repellent. Gas chromatography (GC), GC-linked mass spectrometry (GC-MS) and, where possible, GC-co-injections with authentic compounds, led to the identification of about 34 compounds in the essential oil. About 56% of the constituents were terpenoid ketones, mostly methyl ketones. Phenylacetaldehyde (14.4%), artemisia ketone (10.1%), (1S)-(-)-verbenone (12.1%) and geranyl acetone (9.4%) were the main constituents. Apart from phenylacetaldehyde, repellent activities of the other main constituents were higher than that of the essential oil. The blends of the main constituents in proportions found in the essential oil were more repellent to An. gambiae s.s. than was the parent oil (p < 0.05), and the presence of artemisia ketone in the blend caused a significant increase in the repellency of the resulting blend. These results suggested that blends of some terpenoid ketones can serve as effective An. gambiae s.s. mosquito repellents

    Repellent Properties of δ-Octalactone Against the Tsetse Fly, Glossina morsitans Morsitans

    Get PDF
    δ-octalactone, produced by several Bovidae, has been suggested as a potential repellant of tsetse fly attack. Racemic δ-octalactone was synthesized via an abbreviated route. The product was assayed against 3-day old starved teneral female tsetse flies, Glossina morsitans morsitans Wiedemann (Diptera: Glossinidae), in a choice wind tunnel and found to be a potent tsetse repellent at doses ≥0.05 mg in 200 µl of paraffin oil (0.05 >p >0.01)

    Teatro na educação de crianças e adolescentes participantes de ensaio clínico

    Get PDF
    OBJETIVO: Analisar os efeitos de uma intervenção pedagógica na aprendizagem de crianças e adolescentes participantes de pesquisa clínica. MÉTODOS: Estudo quantitativo, quasi-experimental e longitudinal, parte de um conjunto de estudos envolvidos no teste de uma vacina contra ancilostomíase. Amostra por conveniência com 133 estudantes de dez a 17 anos, de ambos os sexos, da Escola Municipal de Maranhão, MG, Brasil, 2009. Utilizou-se um questionário estruturado aplicado pré e pós-intervenção. O dispositivo pedagógico foi o Teatro do Oprimido. As variáveis dependentes foram o conhecimento específico e global sobre pesquisa clínica e sobre verminoses; a variável independente foi a participação na intervenção educativa. RESULTADOS: Houve aumento do conhecimento sobre sinais e sintomas, susceptibilidade à reinfecção e modo de contágio da verminose após a intervenção educativa. Aumentaram acertos relativos à duração da pesquisa clínica, aos procedimentos previstos, à possibilidade de desistência da participação e de ocorrência de eventos adversos. Permaneceu a noção de que o propósito primário da pesquisa é terapêutico, embora tenha reduzido o percentual de participantes que associaram a pesquisa ao tratamento médico. O Teatro do Oprimido possibilitou que as discussões acerca da helmintose e da pesquisa clínica fossem contextualizadas e materializadas. Os sujeitos puderam se despojar ou reduzir suas representações prévias. CONCLUSÕES: A participação de crianças e adolescentes em ensaios clínicos deve ser precedida de intervenção educativa, já que indivíduos dessa faixa etária nem sequer reconhecem que têm direito a decidir por si próprios

    Heart failure in chronic kidney disease: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies conference

    Get PDF
    The incidence and prevalence of heart failure (HF) and chronic kidney disease (CKD) are increasing, and as such a better understanding of the interface between both conditions is imperative for developing optimal strategies for their detection, prevention, diagnosis, and management. To this end, Kidney Disease: Improving Global Outcomes (KDIGO) convened an international, multidisciplinary Controversies Conference titled Heart Failure in CKD. Breakout group discussions included (i) HF with preserved ejection fraction (HFpEF) and nondialysis CKD, (ii) HF with reduced ejection fraction (HFrEF) and nondialysis CKD, (iii) HFpEF and dialysis-dependent CKD, (iv) HFrEF and dialysis-dependent CKD, and (v) HF in kidney transplant patients. The questions that formed the basis of discussions are available on the KDIGO website http://kdigo.org/conferences/heart-failure-in-ckd/, and the deliberations from the conference are summarized here
    corecore