Browsing by Author "Swai, Hulda"

Now showing 1 - 20 of 67

Abrogating the nsp10–nsp16 switching mechanisms in SARS-CoV-2 by phytochemicals from Withania somnifera: a molecular dynamics study
(Taylor & Francis Online, 2021-09-14) Vuai, Said; Onoka, Isaac; Sahini, Mtabazi; Swai, Hulda; Shadrack, Daniel
The search for therapeutic small molecules and vaccines for Covid-19 treatment is an urgent but evolving topic. The virus has claimed over 3,782,490 lives (as of 12 June 2021), with the figure expected to rise due to the high versatility of the SAR-CoV-2 variant. Therapeutic options based on SARS-CoV-2 inhibitor are essential. Withanolides have a long history in traditional medicines with versatile biological properties including antiviral activities. In this study, the inhibitory potential of withanolides from Withania somnifera (Ashwagandha) against SARS-CoV-2 non-structural protein 10 (nsp10) was investigated by employing atomistic in silico methods viz molecular docking, molecular dynamics and binding free energy calculations. Investigated Withania somnifera compounds demonstrated binding affinity to the nsp10 and in its complex form, that is, nsp10-nsp16 heterodimer. Two withanolides; withanoside IV and withanoside V isolated from the roots of Withania somnifera demonstrated strong inhibition with binding free energies of −29.5 and −29.1 kJ/mol, respectively. Molecular dynamics and binding free energy ascertained the stability of withanoside IV. Water molecules, although known to play an important role in mediating biological systems, herein, water was found to have a repulsive binding effect to some residues, suggesting that the binding of withanoside IV would require dewetting of the nsp10 or displacing the water to bulk solvents. Interestingly, residues in the nsp10 that are responsible for forming stable interaction at the nsp10–nsp16 were found to be strongly interacting with withanoside IV, hence weakening the nsp10–nsp16 interaction and recognition. Further in vitro and in vivo experiments are recommended to validate the anti-SARS-COV-2 potential of these phytochemicals.
Acute and sub-acute toxicity studies of chloroform extracts of cucumis metuliferus and lippia kituiensis in mice and rats model
(World Journal of Pharmaceutical Research, 2020) Mzena, Theopista; Swai, Hulda; Chacha, Musa
Objective: To evaluate the acute and sub-acute oral toxicity of Cucumis metuliferus and Lippia kituiensis leaf chloroform extracts in mice and rats model. Methods: Acute oral toxicity study of chloroform extracts of L. kituiensis and C. metuliferus was carried out by administration of 300, 600, 1500, mg/kg body weight to mice in the respective groups. The LD50 of the C. metuliferus and L. kituiensis extracts was determined to be not greater than 2000 mg/kg body weight. Sub-acute toxicity study was conducted by oral administration of the extracts at daily doses of 150, 300 and 500mg/kg body weight in the respective groups of rats for 28 days, and a positive control consisting of 1% DMSO and 5 mL was given to each. Results: In acute toxicity, all treated groups revealed neither mortality nor significant alteration in behavior, body weight, and hematology parameters. However, the significance different was observed in organ weight at a dose of 600mg/kg and 1500mg/kg of the tested plant extract in both plants. In sub acute study the result revealed neither mortality nor significant alteration in behavior between treated and control. The significant different was observed in body weight in all doses in both plants and organ weight and haematological parameter in dose level 300 mg/kg and 500 mg/kg compared to control. Moreover the significant change was observed in biochemical parameters of both sexes in dose of 300 mg/kg and 500 mg/kg body weight of C. metuliferus and L. kituiensis extract. A significant histological change was observed in liver, kidney, lungs and spleen in all extract of C. metuliferus and L. kituiensis in a dose of 300 mg/kg and 500 mg/kg body weight. Conclusion: These plants can causes‟ severe toxicity to animals.
Antimalarial activity of Cucumis metuliferus and Lippia kituiensis against Plasmodium berghei infection in mice
(Dovepress, 2018) Mzena, Theopista; Swai, Hulda; Chacha, Musa
Background: The search for new antimalarial drugs has become progressively urgent due to plasmodial resistance to most of the commercially available antimalarial drugs. As part of this effort, the study evaluated the antimalarial activity of Cucumis metuliferus and Lippia kituiensis, which are traditionally used in Tanzania for the treatment of malaria. Materials and methods: In vivo antimalarial activity was assessed using the 4-day suppressive antimalarial assay. Mice were infected by injecting via tail vein 1×107 erythrocytes infected by Plasmodium berghei ANKA. Extracts were administered orally; chloroquine (10 mg/kg/day) and dimethyl sulfoxide (5 mL/kg/day) were used as positive and negative controls, respectively. The level of parasitemia, survival time, packed cell volume (PCV) and variation in body weight of mice were used to determine the antimalarial activity of the extract. Results: The ethyl acetate, methanolic and chloroform extracts of C. metuliferus and L. kituiensis significantly (p<0.05) inhibited parasitemia in a dose-dependent manner and prevented loss of body weight at the dose levels of 600 mg/kg and 1500 mg/kg, respectively. In addition, the extracts prolonged the mean survival time of P. berghei-infected mice compared to the non-treated control. The plant extracts did not show reduction of PCV except at the low dose of 300 mg/kg. The highest suppression was recorded at the dose level of 1,500 mg/kg. At this dose, C. metuliferus in chloroform, methanolic and ethyl acetate extracts had percentage suppression of 98.55%, 88.89% and 84.39%, respectively, whereas L. kituiensis in ethyl acetate, chloroform and methanolic extracts exhibited suppression of the pathogens of 95.19%, 93.88% and 74.83%, respectively. Conclusion: It is worth reporting that the two plants induced suppression which is equivalent to that induced by chloroquine (C. metuliferus chloroform and L. Kituiensis ethyl acetate). The two plants have been demonstrated to be potential sources of antimalarial templates.
Antimalarial potential and phytochemical composition of fractions of Lippia kituiensis Vatke (Verbenaceae) growing in Northern Tanzania
(Journal of Medicinal Plants Research, 2020-08-31) Ng’etich, Japheth; Swai, Hulda; Njokah, Joseph; Wachira, Sabina; Koech, Lilian; Gathirwa, Jeremiah
Despite past decades of steady advances in the fight against Malaria, statistics show that the disease is still a threat to human health. Previous successes in the development of antimalarial drugs from medicinal plants have fuelled research in this area. However, antimalarial studies on fractionated extracts from such plants have progressed slowly. This study reports the antimalarial potential of fractions from Lippia kituiensis Vatke, for the first time. Column chromatography was used during fractionation. Antiplasmodial assay against chloroquine-sensitive (D6) and resistant (W2) plasmodium strains were done using hypoxanthine incorporation assay. MTT assay was used to assess the cytotoxicity of fractions against the Vero cell line. Fractions obtained exhibited varied inhibitory concentrations (IC50); with the most efficacious being, Lk-5 (19.45 ± 6.20 μg/ml), Lk-3 (30.43 ± 0.68 μg/ml), Lk-4 (30.82 ± 18.01 μg/ml), and Lk-6 (36.53 ± 14.42 μg/ml) against D6. Generally, lower activity against W2 was obtained with the most active being LK-4 (24.18±2.50 μg/ml), and Lk-5 (24.42±5.95 μg/ml), while chloroquine (positive control) exerted IC50 of 77.86±4.09 ng/ml (W2) and 15.71±6.49 ng/ml (D6). LK-4 was the most cytotoxic showing cytotoxic concentration (CC50), 46.26 μg/ml. When tested in mice, fractions suppressed Plasmodium berghei significantly compared to the negative control with Lk-3 being most efficacious (80.01±1). Due to substantive efficacy, GC-MS done on Lk-3 revealed 8 compounds where three have previously been ascribed to antimalarial activity and other pharmacological effects. This study adds to present knowledge of antimalarial efficacy of L. kituiensis and provides the basis for further work to be done on the isolation of compounds from its extracts.
Antimicrobial dependence of silver nanoparticles on surface plasmon resonance bands against Escherichia coli
(Dove Press Journal, 2016-12-16) Mlalila, Nichrous; Swai, Hulda; Hilonga, Askwar; Kadam, Dattatreya
This study presents a simple and trouble-free method for determining the antimicrobial properties of silver nanoparticles (AgNPs) based on the surface plasmon resonance (SPR) bands. AgNPs were prepared by chemical reduction method using silver nitrates as a metallic precursor and formaldehyde (HCHO) as a reducing agent and capped by polyethylene glycol. Effects of several processing variables on the size and shape of AgNPs were monitored using an ultraviolet–visible spectrophotometer based on their SPR bands. The formed particles showing various particle shapes and full width at half maximum (FWHM) were tested against Escherichia coli by surface spreading using agar plates containing equal amounts of selected AgNPs samples. The NPs exhibited higher antimicrobial properties; however, monodispersed spherical NPs with narrow FWHM were more effective against E. coli growth. The NPs prepared are promising candidates in diverse applications such as antimicrobial agents in the food and biomedical industries.
Antimicrobial packaging based on starch, poly(3-hydroxybutyrate) and poly(lactic-co-glycolide) materials and application challenges
(Elsevier Ltd., 2018-04) Mlalila, Nichrous; Hilonga, Askwar; Swai, Hulda; Devlieghere, Frank; Ragaert, Peter
Background In recent years, food packaging has focused on two scientific pillars; adopting the biodegradable packaging materials and development of antimicrobial packaging for extended shelf life, quality and safety of food products. The bioplastic materials provide a promising application in the packaging industry to substitute environmentally deleterious petrochemical-based plastics. Scope and approach This paper gives insights to very recent progress on the antimicrobial application of starch, polyhydroxybutyrate (PHB) and poly (lactic-co-glycolide) (PLGA) as well as their blends and nanocomposites in food packaging research. It also presents an overview of the antimicrobial application of these materials particularly in food and biomedical industry. Key findings and conclusions PHB, starch and PLGA materials have unique properties towards novel application in foods, cosmetics, medicines as well as various composites. The materials necessitate critical studies to improve their industrial performance both for processing engineering and antimicrobial packaging due to functional and technical limitations.
Catalytic hydrothermal liquefaction of orange peels into biocrude: An optimization approach by central composite design
(Elsevier B.V., 2023-08) Kariim, Ishaq; Waidi, Yusuf; Swai, Hulda; Kivevele, Thomas
Global instability, persistent increase in pump-price, inflation and depletion of fossil fuel resources amidst the continuous discharge of greenhouse gases from fossil fuels combustion call for urgent attention. The application of novel catalyst towards an improved biocrude production and enhanced biomass conversion are required for effective performance of hydrothermal liquefaction of biomass feedstocks. In the present study, iron supported carbon nanospheres (Fe/CNSs) catalyst has been developed using wet impregnation approach and explored for its catalytic potency in improving yield of biocrude using an optimization approach; central composite design. Hydrothermal liquefaction (HTL) was adopted as a process route where the catalyst dosage (3–6 wt%) and the reaction temperature (330–430 °C) were optimized on the constant weight of orange feedstock (10 g), reaction time of (15 mins) and solvents’ ratio of 3:1 (acetone to ethanol). The performance of the catalyst was found to be aided with the even dispersion of the Fe on the surfaces of the CNSs support and improved surface area. The effects of reaction temperature were observed to be more progressive on biocrude yield formation over the catalyst loading. The optimum biocrude yield, solid residue, biomass conversion and gas yield were obtained to be 71.09 wt%, 28.18 wt%, 71.82 wt% and 40.14 mL/g at 430 °C and 3 wt% catalyst loading. The obtained analysis of variance suggests a good correlation between the experimental and predicted data in all responses. The selectivity of Fe/CNSs catalyst to high yield of phenolics and aromatic compounds in the biocrude suggest that, the biocrude can be further be upgraded into transportation fuel through hydrodeoxygenation process. The findings have further suggested the viability of the developed Fe/CNSs as an effective catalyst for improved HTL products in a batch reactor.
Catalytic hydrothermal liquefaction of orange peels into biocrude: An optimization approach by central composite design
(Elsevier, 2023) Kariim, Ishaq; Waidi, Yusuph; Swai, Hulda; Kivevele, Thomas
Global instability, persistent increase in pump-price, inflation and depletion of fossil fuel resources amidst the continuous discharge of greenhouse gases from fossil fuels combustion call for urgent attention. The application of novel catalyst towards an improved biocrude production and enhanced biomass conversion are required for effective performance of hydrothermal liquefaction of biomass feedstocks. In the present study, iron supported carbon nanospheres (Fe/CNSs) catalyst has been developed using wet impregnation approach and explored for its catalytic potency in improving yield of biocrude using an optimization approach; central composite design. Hydrothermal liquefaction (HTL) was adopted as a process route where the catalyst dosage (3–6 wt%) and the reaction temperature (330–430 °C) were optimized on the constant weight of orange feedstock (10 g), reaction time of (15 mins) and solvents’ ratio of 3:1 (acetone to ethanol). The performance of the catalyst was found to be aided with the even dispersion of the Fe on the surfaces of the CNSs support and improved surface area. The effects of reaction temperature were observed to be more progressive on biocrude yield formation over the catalyst loading. The optimum biocrude yield, solid residue, biomass conversion and gas yield were obtained to be 71.09 wt%, 28.18 wt%, 71.82 wt% and 40.14 mL/g at 430 °C and 3 wt% catalyst loading. The obtained analysis of variance suggests a good correlation between the experimental and predicted data in all responses. The selectivity of Fe/CNSs catalyst to high yield of phenolics and aromatic compounds in the biocrude suggest that, the biocrude can be further be upgraded into transportation fuel through hydrodeoxygenation process. The findings have further suggested the viability of the developed Fe/CNSs as an effective catalyst for improved HTL products in a batch reactor.
Catalytic hydrothermal liquefaction of orange peels into biocrude: An optimization approach by Central Composite Design
(Elsevier B.V., 2023-06-01) Kariim, Ishaq; Waidi, Yusuf; Swai, Hulda; Kivevele, Thomas
Global instability, persistent increase in pump-price, inflation and depletion of fossil fuel resources amidst the continuous discharge of greenhouse gases from fossil fuels combustion call for urgent attention. The application of novel catalyst towards an improved biocrude production and enhanced biomass conversion are required for effective performance of hydrothermal liquefaction of biomass feedstocks. In the present study, iron supported carbon nanospheres (Fe/CNSs) catalyst has been developed using wet impregnation approach and explored for its catalytic potency in improving yield of biocrude using an optimization approach; central composite design. Hydrothermal liquefaction (HTL) was adopted as a process route where the catalyst dosage (3-6 wt.%) and the reaction temperature (330-430 oC) were optimized on the constant weight of orange feedstock (10 g), reaction time of (15 mins) and solvents’ ratio of 3:1 (acetone to ethanol). The performance of the catalyst was found to be aided with the even dispersion of the Fe on the surfaces of the CNSs support and improved surface area. The effects of reaction temperature were observed to be more progressive on biocrude yield formation over the catalyst loading. The optimum biocrude yield, solid residue, biomass conversion and gas yield were obtained to be 71.09 wt.%, 28.18 wt. %, 71.82 wt.% and 40.14 mL/g at 430 oC and 3 wt.% catalyst loading. The obtained analysis of variance suggests a good correlation between the experimental and predicted data in all responses. The selectivity of Fe/CNSs catalyst to high yield of phenolics and aromatic compounds in the biocrude suggest that, the biocrude can be further be upgraded into transportation fuel through hydrodeoxygenation process. The findings have further suggested the viability of the developed Fe/CNSs as an effective catalyst for improved HTL products in a batch reactor.
Chitosan-coated liposomes of Carrisa spinarum extract: synthesis, analysis and anti-pneumococcal potency
(ICE Publishing, 2023-02-16) Rubaka, Clarence; Gathirwa, Jeremiah; Malebo, Hamisi; Swai, Hulda; Sibuyi, Nicole; Hilonga, Askwar; Dube, Admire
In the present study, a chitosan (CS)-coated liposome (LipCsP-Chitosan) nanocarrier was fabricated for the delivery of Carissa spinarum (CsP) polyphenols to improve bioavailability and anti-pneumococcal potential against Klebsiella pneumoniae. LipCsP-Chitosan was synthesized by the ion gelation method and characterized by using a Malvern zetasizer and Fourier Transform Infrared (FTIR); CsP encapsulation and release kinetics were investigated. Anti-pneumococcal activity of the nanoformulations was accessed by agar-well diffusion and microdilution assays. LipCsP-chitosan exhibited a hydrodynamic size and zeta potential of 365.22 ± 0.70 nm and +39.30 ± 0.61 mV, respectively. CsP had an encapsulation efficiency of 81.5%. FTIR analysis revealed the interaction of the liposomes with chitosan and the CsP. A biphasic CsP release profile followed by a sustained release pattern was observed. LiPCsP-Chitosan presented a higher bioaccessibility of polyphenols in the simulated gastric phase (74.1% ± 1.3) than in the simulated intestinal phase (63.32% ± 1.00). LipCsP-chitosan had a relative inhibition zone diameter of 84.33% ± 2.51 when compared to CsP. At minimum inhibition concentration of 31.25 mg/mL, LipCsP-Chitosan reduced the viability of Klebsiella pneumoniae by 57.45% ± 3.76 after 24 h. The results obtained from the current study offer a new approach to the utilization of LipCsP-Chitosan as nanocarriers for candidate anti-pneumococcal agents.
Comparative in vitro transportation of pentamidine across the blood-brain barrier using polycaprolactone nanoparticles and phosphatidylcholine liposomes
(Taylor & Francis Group., 2019-04-22) Omarch, Geofrey; Kippie, Yunus; Mentor, Shireen; Ebrahim, Naushaad; Fisher, David; Murilla, Grace; Swai, Hulda; Dube, Admire
Nanoparticles (NPs) have gained importance in addressing drug delivery challenges across biological barriers. Here, we reformulated pentamidine, a drug used to treat Human African Trypanosomiasis (HAT) in polymer based nanoparticles and liposomes and compared their capability to enhance pentamidine penetration across blood brain barrier (BBB). Size, polydispersity index, zeta potential, morphology, pentamidine loading and drug release profiles were determined by various methods. Cytotoxicity was tested against the immortalized mouse brain endothelioma cells over 96 h. Moreover, cells monolayer integrity and transportation ability were examined for 24 h. Pentamidine-loaded polycaprolactone (PCL) nanoparticles had a mean size of 267.58, PDI of 0.25 and zeta potential of –28.1 mV and pentamidine-loaded liposomes had a mean size of 119.61 nm, PDI of 0.25 and zeta potential 11.78. Pentamidine loading was 0.16 mg/mg (w/w) and 0.17 mg/mg (w/w) in PCL NPs and liposomes respectively. PCL nanoparticles and liposomes released 12.13% and 22.21% of pentamidine respectively after 24 h. Liposomes transported 87% of the dose, PCL NPs 66% of the dose and free pentamidine penetration was 63% of the dose. These results suggest that liposomes are comparatively promising nanocarriers for transportation of pentamidine across BBB.
A computational study on the role of water and conformational fluctuations in Hsp90 in response to inhibitors
(Elsevier Inc., 2020-05) Shadrack, Daniel M.; Swai, Hulda; Hassanali, Ali
Molecular chaperone Heat Shock Protein 90 (Hsp90) represents an interesting chemotherapeutic target for cancer treatments as it plays a role in cancer proliferation. Thus, continued effort to identify novel inhibitors of this target is an important task. Drug design using computational approach has gained significant attention in recent years. This work aims to propose docking protocols to re-purpose FDA-approved drugs targeting Hsp90. Sensitivity of results to different docking protocols such apo, holo and receptor ensembles (relaxed complex) structures, the role of water and conformational changes of Hsp90, are described. We show that the protein conformation and water have effects on drug binding. Holo relaxed complex receptors ensembles improves the binding energy of ligands to the protein. We also compare and contrast structural stability of three drugs namely: ezetimibe, pitavastatin and vilazodon in the Hsp90 protein. The results obtained serves as a possible basis towards developing Hsp90 inhibitors.
Curdlan-Conjugated PLGA Nanoparticles Possess Macrophage Stimulant Activity and Drug Delivery Capabilities
(Springer, 2015-03-28) Tukulula, Matshawandile; Hayeshi, Rose; Fonteh, Pascaline; Meyer, Debra; Ndamase, Abongile; Madziva, Michael T.; Khumalo, Vincent; Lubuschagne, Philip; Naicker, Brendon; Swai, Hulda; Dube, Admire
Purpose There is significant interest in the application of nanoparticles to deliver immunostimulatory signals to cells.We hypothesized that curdlan (immune stimulating polymer) could be conjugated to PLGA and nanoparticles from this copolymer would possess immunostimulatory activity, be non-cytotoxic and function as an effective sustained drug release system. Methods Carbodiimide chemistry was employed to conjugate curdlan to PLGA. The conjugate (C-PLGA) was characterized using 1H and 13C NMR, FTIR, DSC and TGA. Nanoparticles were synthesized using an emulsion-solvent evaporation technique. Immunostimulatory activity was characterized in THP-1 derived macrophages. MTTassay and real-time impedance measurements were used to characterize polymer and nanoparticle toxicity and uptake in macrophages. Drug delivery capability was assessed across Caco-2 cells using rifampicin as a model drug. Results Spectral characterization confirmed successful synthesis of C-PLGA. C-PLGA nanoparticles enhanced phosphorylated ERK production in macrophages indicating cell stimulation. Nanoparticles provided slow release of rifampicin across Caco-2 cells. Polymers but not nanoparticles altered the adhesion profiles of the macrophages. Impedance measurements suggested Ca2+ dependent uptake of nanoparticles by the macrophages. Conclusions PLGA nanoparticles with macrophage stimulating and sustained drug delivery capabilities have been prepared. These nanoparticles can be used to stimulate macrophages and concurrently deliver drug in infectious disease therapy.
Design and formulation of nano-sized spray dried efavirenz-part I: influence of formulation parameters
(Springer Nature Switzerland AG., 2012-10-25) Katata, Lebogang; Tshweu, Lesego; Naidoo, Saloshnee; Kalombo, Lonji; Swai, Hulda
Efavirenz (EFV) is one of the first-line antiretroviral drugs recommended by the World Health Organisation for treating HIV. It is a hydrophobic drug that suffers from low aqueous solubility (4 μg/mL), which leads to a limited oral absorption and low bioavailability. In order to improve its oral bioavailability, nano-sized polymeric delivery systems are suggested. Spray dried polycaprolactone-efavirenz (PCL-EFV) nanoparticles were prepared by the double emulsion method. The Taguchi method, a statistical design with an L8 orthogonal array, was implemented to optimise the formulation parameters of PCL-EFV nanoparticles. The types of sugar (lactose or trehalose), surfactant concentration and solvent (dichloromethane and ethyl acetate) were chosen as significant parameters affecting the particle size and polydispersity index (PDI). Small nanoparticles with an average particle size of less than 254 ± 0.95 nm in the case of ethyl acetate as organic solvent were obtained as compared to more than 360 ± 19.96 nm for dichloromethane. In this study, the type of solvent and sugar were the most influencing parameters of the particle size and PDI. Taguchi method proved to be a quick, valuable tool in optimising the particle size and PDI of PCL-EFV nanoparticles. The optimised experimental values for the nanoparticle size and PDI were 217 ± 2.48 nm and 0.093 ± 0.02.
Development and Characterization of Nanovesicles Containing Phenolic Compounds of Carissa spinarum: Encapsulation, Release Kinetics, Antimicrobial Activity and Mathematical Modeling
(Trans Tech Publications Ltd, 2023-05) Rubaka, Clarence; Gathirwa, Jeremiah; Malebo, Hamisi; Swai, Hulda; Hilonga, Askwar
The aim of this study was to develop and characterize a delivery system for polyphenols from an extract of Carissa spinarum leaves, based on liposomes. Liposomes loaded with Carissa spinarum polyphenols (nanoliposomal CsP) were prepared by ethanol-solvent injection method and characterized in terms of zeta potential, size, and polydipersity index by using Zeta sizer and Fourier Transform Infrared spectrum analysis. Total Phenolic content was measured by using Folin-Ciocalteu method and entrapment efficiency was evaluated. The release behavior was conducted in Phosphate Buffer Saline (PBS) solution at pH, 7.4 and Kinetic model fitted to evaluate mechanism of release. Disc diffusion sensitivity test was used to evaluate antimicrobial activity of free extract and nanoliposomal CsP. The mean diameter of nanoliposomal CsP was 181 ± 1.02 nm and had 0.345 ± 0.014 polydipersity index. Zeta potential value for nanoliposomal CsP was-45.6 ± 8.84 mV. Entrapment efficiency under the optimum conditions was 66.11 ± 1.11%. and the nanoliposomal CsP was stable over 30 days. The antibacterial activity of nanoliposomal CsP exhibited inhibition zone diameter of 14.33 ± 1.53 mm and 12.00 ± 1.23 mm against S. aureus and E. coli respectively The results reveal the Carrisa spinarum liposome can be applied as potential carrier for delivery of polyphenols to improves therapeutic action against bacterial strain.
Development of a Natural Product Rich in Bioavailable Omega-3 DHA from Locally Available Ingredients for Prevention of Nutrition Related Mental Illnesses
(Taylor & Francis Online, 2020-03-19) Charles, Christina; Swai, Hulda; Msagati, Titus; Chacha, Musa
Objectives: Poor mental health remains a serious public concern worldwide. The most vulnerable individuals are children and adolescents in developing countries. Nutritional deficiency of long-chain omega-3 fatty acids, particularly docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), have long been recognized as a major contributing factor for mental health illnesses. Provision of ready-to-use natural product rich in preformed Omega-3 DHA and EPA could address this problem. However, most commonly used products are expensive and contain less or no preformed Omega-3 DHA and EPA, making them less suitable for prevention of mental illnesses in resource-poor countries. The main objective of this study was to develop a natural product rich in preformed Omega-3 DHA and EPA from locally available ingredients. Methods: Linear programing (LP) was used to formulate a natural product rich in preformed Omega-3 DHA and other essential nutrients using locally available ingredients other than fish and dairy products. Laboratory analysis was then performed to validate the nutritional value of the LP-formulation using standard analytical methods. The relative difference between the LP tool calculated values, and the laboratory-analyzed values were calculated. Sensory testing was also done to evaluate consumer acceptance of the final product. Results: Optimal formulation contained about 220 mg of preformed Omega-3 DHA + EPA, enough to meet the RDI for children aged 2-10 years. The LP analysis further showed that the cost of the developed product is USD 0.15/100 g, which is 50% lower than that of Plumpy’nut. Laboratory analysis revealed similar results as that of LP at P = 0.05. Conclusions: These findings indicate that ready-to-use natural food rich in preformed DHA and EPA can be developed from locally available ingredients.
Development of a Natural Product Rich in Bioavailable Omega-3 DHA from Locally Available Ingredients for Prevention of Nutrition Related Mental Illnesses.
(Taylor & Francis online, 2020-03-19) Charles, Christina; Swai, Hulda; Msagati, Titus; Chacha, Musa
Poor mental health remains a serious public concern worldwide. The most vulnerable individuals are children and adolescents in developing countries. Nutritional deficiency of long-chain omega-3 fatty acids, particularly docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), have long been recognized as a major contributing factor for mental health illnesses. Provision of ready-to-use natural product rich in preformed Omega-3 DHA and EPA could address this problem. However, most commonly used products are expensive and contain less or no preformed Omega-3 DHA and EPA, making them less suitable for prevention of mental illnesses in resource-poor countries. The main objective of this study was to develop a natural product rich in preformed Omega-3 DHA and EPA from locally available ingredients. Linear programing (LP) was used to formulate a natural product rich in preformed Omega-3 DHA and other essential nutrients using locally available ingredients other than fish and dairy products. Laboratory analysis was then performed to validate the nutritional value of the LP-formulation using standard analytical methods. The relative difference between the LP tool calculated values, and the laboratory-analyzed values were calculated. Sensory testing was also done to evaluate consumer acceptance of the final product. Optimal formulation contained about 220 mg of preformed Omega-3 DHA + EPA, enough to meet the RDI for children aged 2-10 years. The LP analysis further showed that the cost of the developed product is USD 0.15/100 g, which is 50% lower than that of Plumpy'nut. Laboratory analysis revealed similar results as that of LP at P = 0.05. These findings indicate that ready-to-use natural food rich in preformed DHA and EPA can be developed from locally available ingredients.
Development, characterization and antimalarial efficacy of dihydroartemisinin loaded solid lipid nanoparticles.
(Elsevier, 2016-04-01) Omwoyo, Wesley; Melariri, Paula; Gathirwa, Jeremiah; Oloo, Florence; Mahanga, Geoffrey; Kalombo, Lonji; Ogutu, Bernhards; Swai, Hulda
Effective use of dihydroartemisinin (DHA) is limited by poor water-solubility, poor pharmacokinetic profile and unsatisfactory clinical outcome especially in monotherapy. To reduce such limitations, we reformulated DHA into solid lipid nanoparticles (SLNs) as a nanomedicine drug delivery system. DHA-SLNs were characterized for physical parameters and evaluated for in vitro and in vivo antimalarial efficacy. DHA-SLNs showed desirable particle characteristics including particle size (240.7 nm), particle surface charge (+ 17.0 mV), drug loadings (13.9 wt %), encapsulation efficacy (62.3%), polydispersity index (0.16) and a spherical appearance. Storage stability up to 90 days and sustained release of drug over 20 h was achieved. Enhanced in vitro (IC50 0.25 ng/ml) and in vivo (97.24% chemosuppression at 2 mg/kg/day) antimalarial activity was observed. Enhancement in efficacy was 24% when compared to free DHA. These encouraging results show potential of using the described formulation for DHA drug delivery for clinical application.
Effects of protein binding on the biodistribution of PEGylated PLGA nanoparticles post oral administration
(Elsevier B.V., 2012-03-15) Semete, Boitumelo; Booysen, Laetitia; Kalombo, Lonji; Ramalapa, Bathabile; Hayeshi, Rose; Swai, Hulda
The surface of nanoparticles is often functionalised with polymeric surfactants, in order to increase systemic circulation time. This has been investigated mainly for intravenously administered nanoparticles. This study aims to elucidate the effect of surface coating with various concentrations of polymeric surfactants (PEG and Pluronics F127) on the in vitro protein binding as well as the tissue biodistribution, post oral administration, of PLGA nanoparticles. The in vitro protein binding varied depending on the polymeric surfactant used. However, in vivo, 1% PEG and 1% Pluronics F127 coated particles presented similar biodistribution profiles in various tissues over seven days. Furthermore, the percentage of PEG and Pluronics coated particles detected in plasma was higher than that of uncoated PLGA particles, indicating that systemic circulation time can also be increased with oral formulations. The difference in the in vitro protein binding as a result of the different poloxamers used versus similar in vivo profiles of these particles indicates that in vitro observations for nanoparticles cannot represent or be correlated to the in vivo behaviour of the nanoparticles. Our results therefore suggest that more studies have to be conducted for oral formulations to give a better understanding of the kinetics of the particles.
Effects of spray-drying on w/o/w multiple emulsions prepared from a stearic acid matrix
(2014-01-01) Mlalila, Nichrous; Swai, Hulda; Kalombo, Lonji; Hilonga, Askwar
The goal of this study was to explore the effects of spray-drying on w/o/w double emulsions of methyltestosterone (MT) loaded in a stearic acid matrix. MT-loaded nanoparticles were formulated by a water-in-oil-in-water emulsion technique using 50, 75, and 100 mg of stearic acid, 2% and 3% w/v polyvinyl alcohol, 5% w/v lactose, and 0.2% w/v chitosan. The emulsions were immediately spray-dried based on an optimized model of inlet temperature and pump rate, and characterized for optimized responses with regard to particle size, polydispersity index, and zeta potential, for both emulsion and powder samples. Dynamic light scattering analysis shown that the nanoparticles increased in size with increasing concentrations of polyvinyl alcohol and stearic acid. Scanning electron microscopy indicated that the MT-loaded nanoparticles were spherical in shape, had a smooth surface, and were in an amorphous state, which was confirmed by differential scanning calorimetry. These MT-loaded nanoparticles are a promising candidate carrier for the delivery of MT; however, further studies are needed in order to establish the stability of the system and the cargo release profile under normal conditions of use.