18 research outputs found

    Zeolite structures loading with an anticancer compound as drug delivery systems

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    The authors are thankful to Dr. A. S. Azevedo for collecting the powder diffraction data.Two different structures of zeolites, faujasite (FAU) and Linde type A (LTA), were studied to investigate their suitability for drug delivery systems (DDS). The zeolites in the sodium form (NaY and NaA) were used as hosts for encapsulation of α-cyano-4- hydroxycinnamic acid (CHC). CHC, an experimental anticancer drug, was encapsulated in both zeolites by diffusion in liquid phase. These new drug delivery systems, CHC@zeolite, were characterized by spectroscopic techniques (FTIR, 1H NMR, 13C and 27Al solidstate MAS NMR, and UV−vis), chemical analysis, powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effect of the zeolites and CHC@zeolite drug deliveries on HCT-15 human colon carcinoma cell line viability was evaluated. Both zeolites alone revealed no toxicity to HCT-15 cancer cells. Importantly, CHC@zeolite exhibit an inhibition of cell viability up to 585-fold, when compared to the non-encapsulated drug. These results indicate the potential of the zeolites for drug loading and delivery into cancer cells to induce cell deathO.M. and R.A. are recipients of fellowships (SFRH/BD/36463/2007, SFRH/BI/51118/2010) from Fundação para a Ciência e a Tecnologia (FCT, Portugal). This work was supported by the FCT projects refs PEst-C/ QUI/UI0686/2011, PEst-C/CTM/LA0011/2011, and PTDC/ SAU-FCF/104347/2008, under the scope of “Programa Operacional Temático Factores de Competitividade” (COMPETE) of “Quadro Comunitário de Apoio III” and cofinanced by Fundo Comunitário Europeu FEDER, and the Centre of Chemistry and Life and Health Sciences Research Institute (University of Minho, Portugal)

    Quality assessment of information systems in SMEs: A study of Eldoret town, Kenya

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    The use of Information Systems (IS) of acceptable quality has been viewed to be vital for improving the efficiency and effectiveness of business operations. Many SMEs in developing countries are beginning to embrace the use of IS to help improve their competitiveness. This venture, however, has not yielded the much anticipated benefits for many of these SMEs. For this reason, a number SMEs in developing countries have ended up dissatisfied with their IS investments. A considerable percentage IS solutions used within the SMEs in developing countries are inefficient and ineffective in helping meet the unique needs of the SMEs. This paper presents the results of an exploratory study into the quality of IS used within SMEs in Eldoret town, situated in Kenya. The study employs a qualitative research methodology with multiple case studies of seven SMEs. The results of the study indicate that the SMEs that participated in the study use IS solutions that were of unacceptable quality. The study further identifies factors that are responsible for this poor quality of IS and recommends actions that can be taken to improve the quality of IS within the SMEs

    Impact of ICT used within SMEs in Eldoret, Kenya.

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    A number of Small and Medium Enterprises (SMEs) in developing countries are slowly but steadily beginning to embrace the use of Information and Communication Technology (ICT). With such proliferation it is critical that the much anticipated positive impacts from such investments are realized. This has, however, not been true for many SMEs in developing countries, largely because a number of ICT solutions used within the SMEs do not adequately address their unique needs. As a result, many have ended up frustrated with their ICT investments. Our objective in this study was to build a snapshot on the impact of ICT used in SMEs in Eldoret, Kenya. Findings from this study reveal low positive impact of ICT on the SMEs. In the study, we identify factors that are responsible for the low impact of ICT on the SMEs and recommend actions that can be taken to ensure the adopted ICT brings positive change to the SMEs. Impact of ICT used within SMEs in Eldoret, Kenya - ResearchGate. Available from: http://www.researchgate.net/publication/272795296_Impact_of_ICT_used_within_SMEs_in_Eldoret_Kenya [accessed Oct 14, 2015]

    Anti-protozoal activity of aporphine and protoberberine alkaloids from Annickia kummeriae (Engl. & Diels) Setten & Maas (Annonaceae)

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    BACKGROUND: Malaria, trypanosomiasis and leishmaniasis have an overwhelming impact in the poorest countries in the world due to their prevalence, virulence and drug resistance ability. Currently, there is inadequate armory of drugs for the treatment of malaria, trypanosomiasis and leishmaniasis. This underscores the continuing need for the discovery and development of new anti-protozoal drugs. Consequently, there is an urgent need for research aimed at the discovery and development of new effective and safe anti-plasmodial, anti-trypanosomal and anti-leishmanial drugs. METHODS: Bioassay-guided chromatographic fractionation was employed for the isolation and purification of antiprotozoal alkaloids. RESULTS: The methanol extract from the leaves of Annickia kummeriae from Tanzania exhibited a strong anti-plasmodial activity against the multi-drug resistant Plasmodium falciparum K1 strain (IC50 0.12 +/- 0.01 mug/ml, selectivity index (SI) of 250, moderate activity against Trypanosoma brucei rhodesiense STIB 900 strain (IC50 2.50 +/- 0.19 mug/ml, SI 12) and mild activity against Leishmania donovani axenic MHOM-ET-67/82 strain (IC50 9.25 +/- 0.54 mug/ml, SI 3.2). Bioassay-guided chromatographic fractionation led to the isolation of four pure alkaloids, lysicamine (1), trivalvone (2), palmatine (3), jatrorrhizine (4) and two sets of mixtures of jatrorrhizine (4) with columbamine (5) and palmatine (3) with (-)-tetrahydropalmatine (6). The alkaloids showed low cytotoxicity activity (CC50 30 - <90 mug/ml), strong to moderate anti-plasmodial activity (IC50 0.08 +/-

    In vitro antiplasmodial activity and toxicity assessment of plant extracts used in traditional malaria therapy in the Lake Victoria Region

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    As part of our program screening the flora of the Lake Victoria Region, a total of 54 organic extracts from seven plant families (8 species) were individually tested for antiplasmodial activity against chloroquine-sensitive [Sierra Leone (D-6)] and chloroquine-resistant [Vietnam (W-2)] strains. Only 22% of these extracts exhibited very high in vitro antiplasmodial activity. Six methanol (MeOH) extracts and one chloroform extract showed in vitro antiplasmodial activity against the D-6 Plasmodium falciparum strain, while only three MeOH extracts were active against the W-2 strain. All of the ethyl acetate extracts proved to be inactive against both strains of P. falciparum. A brine shrimp cytotoxicity assay was used to predict the potential toxicity of the extracts. The cytotoxicity to antiplasmodial ratios for the MeOH extracts were found to be greater than 100, which could indicate that the extracts are of low toxicity
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