29 research outputs found

    Impact force of melon seeds during shelling

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    Melon seeds are shelled in a rotating impeller – a type of machine to obtain the cotyledons.  The seeds exit the impeller and impact a cylindrical ring shelling the seeds.  Because of the impact force, some of the seeds are broken, which would deteriorate in storage and make lower market value.  An analytical method was used to determine the factors affecting the impact force on the ring.  Experimental compression tests were carried out to determine the static force for breaking melon seeds.  Some seeds were also shelled with an experimental shelling machine and the number of broken seeds was counted. Analysis results showed that the factors affecting the impact force were impeller speed, seed cross-section area at impact and mass ratio.  The mean forces for breaking melon seeds were 13.14×10-3 N, 19.62×10-3 N and 19.55×10-3 N for orientations of breadthwise, lengthwise with tip up and lengthwise with tip down respectively.Keywords: impact force, melon seeds, shelling, analysis Citation: Okokon F. B., E. Ekpenyong, C. Nwaukwa, N. Akpan, and F. I. Abam.  Impact force of melon seeds during shelling.  Agric Eng Int: CIGR Journal, 2010, 12(1): 182-188.&nbsp

    In vivo efficacy and metabolism of the antimalarial cycleanine and improved in vitro antiplasmodial activity of novel semisynthetic analogues.

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    Bisbenzylisoquinoline (BBIQ) alkaloids are a diverse group of natural products that demonstrate a range of biological activities. In this study, the in vitro antiplasmodial activity of three BBIQ alkaloids (cycleanine (1), isochondodendrine (2) and 2'-norcocsuline (3)) isolated from the Triclisia subcordata Oliv. medicinal plant traditionally used for the treatment of malaria in Nigeria are studied alongside two semi-synthetic analogues (4 and 5) of cycleanine. The antiproliferative effects against a chloroquine-resistant Plasmodium falciparum strain were determined using a SYBR Green 1 fluorescence assay. The in vivo antimalarial activity of cycleanine (1) is then investigated in suppressive, prophylactic and curative murine malaria models after infection with a chloroquine-sensitive Plasmodium berghei strain. BBIQ alkaloids (1-5) exerted in vitro antiplasmodial activities with IC50 at low micromolar concentrations with the two semi-synthetic cycleanine analogues showing an improved potency and selectivity than cycleanine. At oral doses of 25 and 50mg/kg body weight of infected mice, cycleanine suppressed the levels of parasitaemia, and increased mean survival times significantly compared to the control groups. The metabolites and metabolic pathways of cycleanine (1) were also studied using high performance liquid chromatography electrospray ionization tandem mass spectrometry. Twelve novel metabolites were detected in rats after intragastic administration of cycleanine. The metabolic pathways of cycleanine were demonstrated to involve hydroxylation, dehydrogenation, and demethylation. Overall, these in vitro and in vivo results provide a basis for the future evaluation of cycleanine and its analogues as leads for further development

    A characterization of the antimalarial activity of the bark of Cylicodiscus gabunensis Harms

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    ETHNOPHARMACOLOGICAL RELEVANCE AND AIM: A decoction of the bark of Cylicodiscus gabunensis Harms is used as a traditional medicine in the treatment of malaria in Nigeria. This study aims to validate the antimalarial potency of this decoction in vitro against Plasmodium falciparum and define potential bioactive constituents within the C. gabunensis bark. MATERIALS AND METHODS: A bioassay-guided separation and fractionation protocol was applied to C. gabunensis extracts, exploiting the use of a Malaria Sybr Green I Fluorescence assay method to monitor antiproliferative effects on parasites as well as define 50% inhibition concentrations. Spectroscopic techniques, including GC-MS, TOF LC-MS and (1)H NMR were used to identify phytochemicals present in bioactive fractions. Analogues of gallic acid were synthesized de novo to support the demonstration of the antimalarial action of phenolic acids identified in C. gabunensis bark. In vitro cytotoxicity of plant extracts, fractions and gallate analogues was evaluated against the HepG2 cell line. RESULTS: The antimalarial activity of ethanolic extracts of C. gabunensis bark was confirmed in vitro, with evidence for phenolic acids, primarily gallic acid and close analogues such as ethyl gallate, likely providing this effect. Further fraction produced the most potent fraction with a 50% inhibitory concentration of 4.7µg/ml. Spectroscopic analysis, including (1)H NMR, LC-MS and GC-MS analysis of this fraction and its acid hydrolyzed products, indicated the presence of conjugates of gallic acid with oligosaccharides. The extracts/fractions and synthetic alkyl gallate showed moderate selectivity against P. falciparum. CONCLUSIONS: These results support the use of the bark of C. gabunensis as a traditional medicine in the treatment of human malaria, with phenolic acid oligosaccharide complexes evident in the most bioactive fractions

    Use of the WHO Access, Watch, and Reserve classification to define patterns of hospital antibiotic use (AWaRe): an analysis of paediatric survey data from 56 countries

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    BACKGROUND: Improving the quality of hospital antibiotic use is a major goal of WHO's global action plan to combat antimicrobial resistance. The WHO Essential Medicines List Access, Watch, and Reserve (AWaRe) classification could facilitate simple stewardship interventions that are widely applicable globally. We aimed to present data on patterns of paediatric AWaRe antibiotic use that could be used for local and national stewardship interventions. METHODS: 1-day point prevalence survey antibiotic prescription data were combined from two independent global networks: the Global Antimicrobial Resistance, Prescribing, and Efficacy in Neonates and Children and the Global Point Prevalence Survey on Antimicrobial Consumption and Resistance networks. We included hospital inpatients aged younger than 19 years receiving at least one antibiotic on the day of the survey. The WHO AWaRe classification was used to describe overall antibiotic use as assessed by the variation between use of Access, Watch, and Reserve antibiotics, for neonates and children and for the commonest clinical indications. FINDINGS: Of the 23 572 patients included from 56 countries, 18 305 were children (77·7%) and 5267 were neonates (22·3%). Access antibiotic use in children ranged from 7·8% (China) to 61·2% (Slovenia) of all antibiotic prescriptions. The use of Watch antibiotics in children was highest in Iran (77·3%) and lowest in Finland (23·0%). In neonates, Access antibiotic use was highest in Singapore (100·0%) and lowest in China (24·2%). Reserve antibiotic use was low in all countries. Major differences in clinical syndrome-specific patterns of AWaRe antibiotic use in lower respiratory tract infection and neonatal sepsis were observed between WHO regions and countries. INTERPRETATION: There is substantial global variation in the proportion of AWaRe antibiotics used in hospitalised neonates and children. The AWaRe classification could potentially be used as a simple traffic light metric of appropriate antibiotic use. Future efforts should focus on developing and evaluating paediatric antibiotic stewardship programmes on the basis of the AWaRe index. FUNDING: GARPEC was funded by the PENTA Foundation. GARPEC-China data collection was funded by the Sanming Project of Medicine in Shenzhen (SZSM2015120330). bioMérieux provided unrestricted funding support for the Global-PPS

    Pharmacological Studies On Root Extract Of Vernonia amygdalina

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    Administration of ethanolic extract of root of Vernonia amygdalina (100,200,400,600mg/kg p.o) offered significant (P>0.05) protection against pentylenetetrazole (PTZ)- induced lethality. The extract also had a significant (p > 0.05) analgesic activity against acetic acid induced abdominal constriction in a dose dependent fashion compared to control. It exhibited an antipyretic activity which was significant (p>0.05) compared to control but was less effective than acetyl salicylic acid. These observations suggested that the root extract possesses a CNS depressant action. Key words: Vernonia amygdalina, Compositae, anticonvulsant, analgesic, antipyretic. Nig. J. Nat. Prod. and Med. Vol.8 2004: 59-6

    Antiulcerogenic Activity of Ethanolic Leaf Extract of Croton Zambesicus Muell. Arg

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    Croton Zambesicus Muell. Arg. is often used in traditional medicine by Ibibios of Niger Delta region of Nigeria for the treatment of several diseases including gastrointestinal disorders especially ulcer. The antiulcer activity of the ethanolic extract of the crude leaf extract was investigated against indomethacin, ethanol and histamine – induced ulcer models in rats. The crude leaf extract of Croton zambesicus (200 – 600mg/kg) significantly (p<0.001) inhibited ulcers produced by the ulcerogens used; indomethacin, ethanol and histamine.The results of this work suggest that the leaf extract of Croton zambesicus possesses antiulcer activity, supporting the ethnomedical use of the plant

    Antiulcerogenic Activity of Ethanolic Leaf Extract of Croton zambesicus in Rats

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    Croton zambesicus Muell. Arg. is often used in traditional medicine by Ibibios of Niger Delta region of Nigeria for the treatment of several diseases including gastrointestinal disorders especially ulcer. The antiulcer activity of the ethanolic extract of the crude leaf extract was investigated against indomethacin, ethanol and histamine – induced ulcer models in rats. The crude leaf extract of Croton zambesicus (200 – 600mg/kg) significantly (p<0.001) inhibited chemically – induced ulcers in rats. These effects may in part be due to phytochemical constituents of the extract. The results of this work suggest that the leaf extract of Croton zambesicus possesses antiulcer activity, supporting the ethnomedical use of the plant among the Ibibio tribe of Niger Delta

    In vitro and in vivo antimalarial activity and chemical profiling of sugarcane leaves.

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    Saccharum officinarum Linn. (sugarcane, Family-Poaceae) is employed in Ibibio traditional medicine for the treatment of various infections and diseases such as malaria. We This study aims to assess the antiplasmodial effect of the leaf extract and fractions on human malaria parasite (Plasmodium falciparum) in vitro, and rodent malaria parasite (P. berghei) in vivo, and analyse the bioactive components of the active fraction(s). The leaf extract and fractions of S. officinarum were prepared and their growth inhibitory effects tested against the chloroquine resistant P. falciparum strain (Dd2) and P. berghei infection in mice. An acute toxicity of the extract was determined. A combination of gas chromatography and liquid chromatography-mass spectrometry, and nuclear magnetic resonance spectroscopy was applied for metabolites profiling of crude extract and active fractions. The leaf extract and fractions demonstrated moderate activity against P. falciparum with the dichloromethane fraction producing the most potent activity (EC50 = 15.4 µg/mL). The leaf extract (170-510 mg/kg, p.o., LD50 = 1732 mg/kg) and fractions demonstrated significant (p < 0.05-0.001) effect on P. berghei infection in prophylactic  tests as well as in established infection with n-butanol fractions producing the highest effect. An unusual sulphur-containing compound, dilaurylthiodipropionate, fatty acids, phenolic acids, flavonoid and flavonoid glycoside were identified in the active fractions. These results give credence to the use of sugarcane leaves as malarial remedy locally by confirming the in vitro and in vivo antiplasmodial potential of leaf extract/fractions of S. officinarum
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