Home About us Contact
|
Home About us Contact | ||
|
|
||
Activity Test (activity + test)
Selected AbstractsPeroxidase activity, chlorophylls and antioxidant profile of two leaf vegetables (Solanum nigrum L. and Amaranthus cruentus L.) under six pretreatment methods before cookingINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 1 2008Odunayo Clement Adebooye Summary The study evaluated the effects of six pretreatment methods before cooking on the peroxidase activity, chlorophyll and antioxidant profile of Amaranthus cruentus L. and Solanum nigrum L. The six pretreatments methods used were chopped only (raw sample) (coded M1); chopped and dried at 50 °C for 5 h (coded M2); chopped and squeezed in water (at room temperature) (coded M3); chopped and soaked in warm water (approximately 60 °C), then cooled and squeezed (coded M4); chopped and soaked in salt-treated water (approximately 20 g NaCl per litre of water) for 15 min, then squeezed (coded M5) and chopped and soaked in boiling water (100 °C), then cooled and squeezed (coded M6). The main effect of vegetable type and the main effect of pretreatment methods have significant effects (P 0.05) on the parameters measured, while the interaction of vegetable type and pretreatment methods have no significant effect on the parameters measured. Statistical analyses (P 0.05) showed that chlorophyll a and b occur in ratio 3:1 in the two vegetables, irrespective of the pretreatment imposed. Peroxidase activity test showed that A. cruentus, irrespective of the pretreatment imposed showed, no peroxidase activity, while S. nigrum showed high peroxidase activity for all the pretreatments except for M6. Results showed that there was a significantly (P 0.05) higher content of carotenoids in A. cruentus when compared with S. nigrum, while the total phenolics, total flavonoids and total tannins contents were higher in S. nigrum when compared with A. cruentus, irrespective of the pretreatment method used. For the two vegetables, the percentage losses in total carotenoids, phenolics, flavonoids and total tannins at M6 when compared with M1 were 53.3,60.5%, 55.6,57.1%, 62.4,63.6% and 66.1,73.5%, respectively. There was a sharp drop in the carotenoids, phenolics, flavonoids and tannins contents of the two vegetables at M4 and M6, with both treatments having closely similar values for each parameter. [source] Physicochemical characterization and antioxidant activity of quercetin-loaded chitosan nanoparticlesJOURNAL OF APPLIED POLYMER SCIENCE, Issue 2 2008Yuying Zhang Abstract Quercetin is an abundant flavonoid in food plants with numerous biological activities and widely used as a potent antioxidant. Being sparingly soluble in water and subject to degradation in aqueous intestinal fluids, the absorption of quercetin is limited upon oral administration. In the present study, chitosan nanoparticles and quercetin-loaded nanoparticles were prepared based on the ionic gelation of chitosan with tripolyphosphate anions. The encapsulation of quercetin in the chitosan nanoparticles were confirmed by differential scanning calorimetry, X-ray powder diffractometry, Fourier transformed infrared spectroscopy, ultraviolet-visible spectrum, and fluorescence spectrum. The morphology of the nanoparticles was characterized by atomic force microscopy. The antioxidant activity of the quercetin-nanoparticles was also evaluated in vitro by two different methods (free radical scavenging activity test and reducing power test), which indicates that inclusion of quercetin in chitosan nanopaticles may be useful in improving the bioavailabilty of quercetin. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008 [source] The effect of long-term streptozotocin-induced diabetes mellitus (STZ-DM) on cynomolgus (Macaca Fascicularis) monkeysJOURNAL OF MEDICAL PRIMATOLOGY, Issue 1 2009D. Wu Abstract Background, This study aimed to retrospectively analyze the effect of long-term streptozotocin-induced diabetes mellitus (STZ-DM) on adolescent cynomolgus monkeys. Methods, A total of 12 monkeys (six STZ-DM and six controls) were monitored for fasting glucose levels and locomotor activities, tested for hematological and serum parameters, measured for body weight and somatometric values. Results, Fasting glucose was maintained at high levels in STZ-DM monkeys. At the age when normal adolescent monkeys dramatically increased their weight, STZ-DM led to the retardation of weight increase in diabetic monkeys. Moreover, STZ-DM monkeys showed abnormal lipid levels and somatometric measurements. In locomotor activity test, STZ-DM monkeys were more active than control ones. Conclusions, Long-term STZ-DM disrupts the normal growth of young monkeys and interferes with some aspects of hormone, lipid metabolism and physical activities. Mean plasma glucose (MPG) appeared to be an important factor in physical activity abnormalities of STZ-DM monkeys. [source] The anxiolytic effect of Sho-ju-sen, a Japanese herbal medicine, assessed by an elevated plus-maze test in micePHYTOTHERAPY RESEARCH, Issue 2 2001Hisashi Kuribara Abstract Sho-ju-sen (SK), a Japanese herbal medicine with a nourishing tonic action, is composed of a water extract of Kumazasa leaves (Sasa kurinensis Makino et Sibata) (SS), and ethanol extracts of Japanese red pine needles (Pinus densiflora Sieb. et Zucc) (PN) and Ginseng roots (Panax ginseng C. A. Meyer) (PX) in the ratio 8:1:1. In this study, an elevated plus-maze test in mice was carried out to assess whether SK had an anxiolytic effect. No significant change was observed in either the plus-maze or activity test following a single administration of SK (10 and 20,mL/kg p.o.). However, mice allowed a free intake of SK (10% solution) for 5 days and longer showed a significant prolongation of the time spent in the open arms (an anxiolytic effect), as long as that caused by the benzodiazepine anxiolytic diazepam (1,mg/kg p.o.). SK (1%, 3% and 30% solutions for 7 days) tended to develop the anxiolytic effect. Of the constituents of SK, SS (8% solution), but not PN (1% solution) or PX (1% solution), resulted in the anxiolytic effect. Except for a slight acceleration in the motor activity by PN (1% solution), no significant change in the motor activity was produced by any treatment with SK, SS or PX. The combined treatment of SK (10% solution) or SS (8% solution) with 1,mg/kg diazepam enhanced the anxiolytic effect. Flumazenil (0.1,mg/kg s.c.), a benzodiazepine receptor antagonist, alone did not change the time spent in the open arms. However, it completely reversed the anxiolytic effect of SK, SS and diazepam. The present results suggest that: (1) long-term treatment with SK develops an anxiolytic effect, (2) SS is the main constituent for the anxiolytic effect of SK, and (3) benzodiazepine receptors are involved in the anxiolytic effect of SK and SS. Copyright © 2001 John Wiley & Sons, Ltd. [source] Synthesis, characterization, and in vitro antimicrobial activities of organotin(IV) complexes of Schiff bases with ONO-type donor atomsHETEROATOM CHEMISTRY, Issue 6 2010Gülgün Yeni, ehirli A new series of diorganotin complexes of the type R2SnL (L1: N -(2-hydroxy-5-chlorophenyl)- 3-ethoxysalicylideneimine, R = Me, (Me2SnL1), R = n -Bu, (n -Bu2SnL1), R = Ph, (Ph2SnL1), L2: N -(2-hydroxy-4-nitro-5-chlorophenyl)-3-ethoxysalicylideneimine, R = Ph, Ph2SnL2, L3: N -(2-hydroxy-4-nitrophenyl)-3-methoxysalicylideneimine, R = Me, (Me2SnL3), R = n -Bu, (n -Bu2SnL3), L4: N -(2-hydroxy-4-nitrophenyl)-3-ethoxysalicylideneimine, R = Me, (Me2SnL4), R = n -Bu, (n -Bu2SnL4)) were synthesized and characterized by elemental analysis, infrared (IR), 1H, and 13C NMR mass spectroscopic techniques, and electrochemical measurements. Ph2SnL1 and Ph2SnL2 were also characterized by X-ray diffraction analysis and were found to show a fivefold C2NO2 coordination geometry nearly halfway between a trigonal bipyramidal and distorted square pyramidal arrangement. The CSnC angles in the complexes were calculated using Lockhart's equations with the 1J(117/119Sn- 13C) and 2J(117/119Sn- 1H) values from the 1H NMR and 13C NMR spectra. Biocidal activity tests against several micro-organisms and some fungi indicate that all the complexes are mildly active against Gram (+) bacteria and the fungi, A. niger and inactive against Gram (,) bacteria. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 21:373,385, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20628 [source] Enantioselective Reduction of 4-Fluoroacetophenone at High Substrate Concentration using a Tailor-Made Recombinant Whole-Cell CatalystADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 4-5 2007Harald Gröger Abstract A practical and highly efficient biocatalytic synthesis of optically active (R)-4-fluorophenylethan-1-ol has been developed based on reduction of the corresponding 4-fluoroacetophenone in the presence of a tailor-made recombinant whole-cell biocatalyst, containing an alcohol dehydrogenase and a glucose dehydrogenase. The reaction proceeds in a pure aqueous solvent media at a substrate concentration of ca. 0.5,M, and gives the desired product with high conversion (>95,%), good yield (87,%) and with an excellent enantioselectivity of >99,% ee. In addition, activity tests further showed that also the analogous 2- and 3-fluoroacetophenones are promising substrates. [source] The in vitro antioxidant and antimicrobial activities of the essential oil and methanol extracts of Achillea biebersteini Afan. (Asteraceae)PHYTOTHERAPY RESEARCH, Issue 6 2004Atalay Sökmen Abstract The essential oil and methanol extracts from A. biebersteinii Afan. (Asteraceae) were evaluated for their antimicrobial and antioxidant activities in vitro. The oil showed stronger antimicrobial activity than the extracts. Their antioxidant features were also evaluated using diphenyl-1-picrylhydrazyl (DPPH), inhibition of superoxide and hydroxyl radicals and inhibition of the lipid peroxidation assays. Particularly, polar subfraction of the methanol extract showed antioxidant activity. The GC-MS analysis of the oil has resulted in the identi,cation of 23 components; piperitone, eucalyptol, camphor, chrysanthenone and borneol were the main components. Antimicrobial activity tests carried out with the fractions of the oil showed that the activity was mainly observed in those containing eucalyptol and camphor, in particular, followed by borneol and piperitone. Copyright © 2004 John Wiley & Sons, Ltd. [source] Optimization of Allium sativum Solvent Extraction for the Inhibition of in Vitro Growth of Helicobacter PyloriBIOTECHNOLOGY PROGRESS, Issue 6 2002Pablo Cañizares Helicobacter pylori (Hp) is the bacterium responsible for serious gastric diseases such as ulcers and cancer. The work described here involved the study of the inhibitory power of Allium sativum extracts against the in vitro growth of Hp(Hp ivg). We used purple garlic of the "Las Pedroñeras" variety for this study. The effects of two different extraction methods (Soxhlet, stirred tank extractor) and four solvents with different characteristics (water, acetone, ethanol, and hexane) were investigated in terms of the efficiency of the extraction process. Satisfactory results were obtained in most cases in the activity tests, indicating that different extracts gave rise to good inhibitory activity against Hp ivg. The extracts that showed the highest bacteriostatic activities were selected to evaluate the influence of the most important operation variables on the extraction yield: stirring speed, operation time, garlic conditioning, and garlic storage time. The best results were obtained using ethanol and acetone as solvents in a stirred tank. The inhibitory powers of these extracts were compared to those shown by some commercial antibiotics used in the medical treatment of Hp infections. The results of this study show that garlic extracts produce levels of inhibition similar to those of the commercial materials. These extracts were also tested against other common bacteria, and equally satisfactory results were obtained. The research described here represents an important starting point in the fight against and/or prevention of peptic ulcers, as well as other pathologies associated with Hp infections such us gastric cancer. The extracted material can be used by direct application and involves a simple and economical extraction procedure that avoids isolation or purification techniques. [source] | |||||||||||||