Displaying publications 81 - 100 of 888 in total

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  1. 4-chloro-1,2-phenylenediamine induces apoptosis in Mardin-Darby canine kidney cells via activation of caspases
    Onn LC, Ching CS, Lian TY, Foon LV, Chew Hee N, Moi CS
    Environ Toxicol, 2014 Jun;29(6):655-64.
    PMID: 22778066 DOI: 10.1002/tox.21792
    4-Chloro-1,2-phenylenediamine (4-Cl-o-PD) is a halogenated aromatic diamine that was used as a precursor for manufacturing permanent hair dyes. Despite its well-documented mutagenic and carcinogenic effects in a number of in vitro and in vivo models, its cytotoxicity and mode of action have not received similar attention. Here, we investigated the effect of 4-Cl-o-PD on Mardin-Darby canine kidney cells. It induced apoptosis and the evidence suggests its initiation by reactive oxygen species (ROS). The results of various assays used show a dose-dependent (i) decrease in cell viability, (ii) increase in cells at sub-G1 phase and the G0/G1 phase arrested in cell cycle, (iii) increase in intracellular ROS accompanied by depletion of glutathione, and (iv) that apoptotic cell death probably involves activation of both intrinsic and extrinsic pathways.
    Matched MeSH terms: Cell Survival/drug effects
  2. Neuroprotective activity of galloylated cyanogenic glucosides and hydrolysable tannins isolated from leaves of Phyllagathis rotundifolia
    Tan HP, Wong DZ, Ling SK, Chuah CH, Kadir HA
    Fitoterapia, 2012 Jan;83(1):223-9.
    PMID: 22093753 DOI: 10.1016/j.fitote.2011.10.019
    The galloylated cyanogenic glucosides based on prunasin (1-7), gallotannins (8-14), ellagitannins (15-17), ellagic acid derivatives (18, 19) and gallic acid (20) isolated from the leaves of Phyllagathis rotundifolia (Melastomataceae) were investigated for their neuroprotective activity against hydrogen peroxide (H(2)O(2))-induced oxidative damage in NG108-15 hybridoma cell line. Among these compounds, the gallotannins and ellagitannins exhibited remarkable neuroprotective activities against oxidative damage in vitro as compared to galloylated cyanogenic glucosides and ellagic acid derivatives in a dose-dependent manner. They could be explored further as potential natural neuroprotectors in various remedies of neurodegenerative diseases.
    Matched MeSH terms: Cell Survival/drug effects
  3. Bioactive oligostilbenoids from Shorea maxwelliana King and their chemotaxonomic significance
    Zawawi NK, Ahmat N, Mazatulikhma MZ, Shafiq RM, Wahid NH, Sufian AS
    Nat Prod Res, 2013;27(17):1589-93.
    PMID: 23035830 DOI: 10.1080/14786419.2012.730047
    Phytochemical investigation on the stem bark of Shorea maxwelliana yielded five oligostilbenoids identified as α-viniferin (1), maximol A (2), vaticanol A (3), suffruticosol A (4) and vaticanol G (5). Chemotaxonomy of isolated compounds was discussed briefly. Major compounds were tested for neurotoxic and cytotoxic activities. Neurotoxicity for all tested compounds did not pose any toxic effect against cultured cell (cell viability range ±100-94%). Compounds 2-5 possessed active cyctotoxic activity against HL60 cell line with IC50 values range of 2.7-78 µg mL(-1).
    Matched MeSH terms: Cell Survival/drug effects
  4. Fulltext Flavone enhances dengue virus type-2 (NGC strain) infectivity and replication in vero cells
    Zandi K, Lani R, Wong PF, Teoh BT, Sam SS, Johari J, et al.
    Molecules, 2012;17(3):2437-45.
    PMID: 22374315 DOI: 10.3390/molecules17032437
    This study investigates the effects of 2-phenyl-1-benzopyran-4-one (flavone) on DENV-2 infectivity in Vero cells. Virus adsorption and attachment and intracellular virus replication were investigated using a foci forming unit assay (FFUA) and quantitative RT-PCR, respectively. Addition of flavone (100 μg/mL) significantly increased the number of DENV-2 foci by 35.66% ± 1.52 and 49.66% ± 2.51 when added during and after virus adsorption to the Vero cells, respectively. The average foci size after 4 days of infection increased by 33% ± 2.11 and 89% ± 2.13. The DENV-2 specific RNA copy number in the flavone-treated infected cells increased by 6.41- and 23.1-fold when compared to the mock-treated infected cells. Flavone (100 μg/mL) did not promote or inhibit Vero cell proliferation. The CC₅₀ value of flavone against Vero cells was 446 µg/mL. These results suggest that flavone might enhance dengue virus replication by acting antagonistically towards flavonoids known to inhibit dengue virus replication.
    Matched MeSH terms: Cell Survival/drug effects
  5. Cytotoxic effect of organotin(IV) benzylisopropyldithiocarbamate compounds on Chang liver cell and hepatocarcinoma HepG2 cell
    Awang N, Kamaludin NF, Ghazali AR
    Pak J Biol Sci, 2011 Aug 01;14(15):768-74.
    PMID: 22303582
    Cancer is one of the main causes of mortality and morbidity in world. New compounds are currently being synthesized to combat this disease. The organotins are gaining more attention as anti-cancer agents due to their potent cytotoxicity properties. In this study, a series of newly synthesized organotins namely dimethyltin (IV) (compound 1), dibutyltin (IV) (compound 2) and triphenyltin (IV) benzylisopropyldithiocarbamate (compound 3) were assessed for their cytotoxic activities against human Chang liver cells and hepatocarcinoma HepG2 cells. The cytotoxicity of these organotins in both cells upon 24 h treatment was assessed using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Compound 2 and 3 exhibited potent cytotoxic activities towards both cells where the IC50 values were less then 10 microM. The IC50 value for compound 2 was 2.5 microM in Chang liver cells and 7.0 microM in HepG2 cells whereas compound 3 exhibited an IC50 value of 1.5 microM in Chang liver cells and 2.5 microM in HepG2 cells. Therefore, compound 2 and 3 were more toxic against human Chang liver cells as compared to hepatocarcinoma HepG2 cells. Interestingly, compound 1 did not have any IC50 value in both cells and hence can be classified as non-toxic. In conclusion, organotin (IV) benzylisopropyldithiocarbamate with insertion of dibutyl and triphenyl functional group possess potent cytotoxicity properties. Structural modification of these compounds can be carried out in further studies to produce less or non toxic effects towards normal human cell.
    Matched MeSH terms: Cell Survival/drug effects
  6. 3,5-dibenzyloxy-4'-hydroxystilbene induces early caspase-9 activation during apoptosis in human K562 chronic myelogenous leukemia cells
    Roslie H, Chan KM, Rajab NF, Velu SS, Kadir SA, Bunyamin I, et al.
    J Toxicol Sci, 2012 Feb;37(1):13-21.
    PMID: 22293408
    A series of 22 stilbene derivatives based on resveratrol were synthesized incorporating acetoxy-, benzyloxy-, carboxy-, chloro-, hydroxy- and methoxy functional groups. We examined the cytotoxicity of these 22 stilbenes in human K562 chronic myelogenous leukemia cells. Only four compounds were cytotoxic namely 4'-hydroxy-3-methoxystilbene (15), 3'-acetoxy-4-chlorostilbene (19), 4'-hydroxy-3,5-dimethoxystilbene or pterostilbene (3) and 3,5-dibenzyloxy-4'-hydroxystilbene (28) with IC(50)s of 78 µM, 38 µM, 67 µM and 19.5 µM respectively. Further apoptosis assessment on the most potent compound, 28, confirmed that the cells underwent apoptosis based on phosphatidylserine externalization and loss of mitochondrial membrane potential. Importantly, we observed a concentration-dependent activation of caspase-9 as early as 2 hr with resultant caspase-3 cleavage in 28-induced apoptosis. Additionally, a structure-activity relationship (SAR) study proposed a possible mechanism of action for compound 28. Taken together, our data suggests that the pro-apoptotic effects of 28 involve the intrinsic mitochondrial pathway characterized by an early activation of caspase-9.
    Matched MeSH terms: Cell Survival/drug effects
  7. Fulltext Shelf-life evaluation of bilayered human skin equivalent, MyDerm™
    Seet WT, Manira M, Maarof M, Khairul Anuar K, Chua KH, Ahmad Irfan AW, et al.
    PLoS One, 2012;7(8):e40978.
    PMID: 22927903 DOI: 10.1371/journal.pone.0040978
    Skin plays an important role in defense against infection and other harmful biological agents. Due to its fragile structure, skin can be easily damaged by heat, chemicals, traumatic injuries and diseases. An autologous bilayered human skin equivalent, MyDerm™, was engineered to provide a living skin substitute to treat critical skin loss. However, one of the disadvantages of living skin substitute is its short shelf-life, hence limiting its distribution worldwide. The aim of this study was to evaluate the shelf-life of MyDerm™ through assessment of cell morphology, cell viability, population doubling time and functional gene expression levels before transplantation. Skin samples were digested with 0.6% Collagenase Type I followed by epithelial cells dissociation with TrypLE Select. Dermal fibroblasts and keratinocytes were culture-expanded to obtain sufficient cells for MyDerm™ construction. MyDerm™ was constructed with plasma-fibrin as temporary biomaterial and evaluated at 0, 24, 48 and 72 hours after storage at 4°C for its shelf-life determination. The morphology of skin cells derived from MyDerm™ remained unchanged across storage times. Cells harvested from MyDerm™ after storage appeared in good viability (90.5%±2.7% to 94.9%±1.6%) and had short population doubling time (58.4±8.7 to 76.9±19 hours). The modest drop in cell viability and increased in population doubling time at longer storage duration did not demonstrate a significant difference. Gene expression for CK10, CK14 and COL III were also comparable between different storage times. In conclusion, MyDerm™ can be stored in basal medium at 4°C for at least 72 hours before transplantation without compromising its functionality.
    Matched MeSH terms: Cell Survival/drug effects
  8. Fulltext An evaluation of dose equivalence between synchrotron microbeam radiation therapy and conventional broad beam radiation using clonogenic and cell impedance assays
    Ibahim MJ, Crosbie JC, Yang Y, Zaitseva M, Stevenson AW, Rogers PA, et al.
    PLoS One, 2014;9(6):e100547.
    PMID: 24945301 DOI: 10.1371/journal.pone.0100547
    High-dose synchrotron microbeam radiation therapy (MRT) has shown the potential to deliver improved outcomes over conventional broadbeam (BB) radiation therapy. To implement synchrotron MRT clinically for cancer treatment, it is necessary to undertake dose equivalence studies to identify MRT doses that give similar outcomes to BB treatments.
    Matched MeSH terms: Cell Survival/radiation effects
  9. Fulltext Release behavior and toxicity profiles towards leukemia (WEHI-3B) cell lines of 6-mercaptopurine-PEG-coated magnetite nanoparticles delivery system
    Dorniani D, Kura AU, Hussein-Al-Ali SH, bin Hussein MZ, Fakurazi S, Shaari AH, et al.
    ScientificWorldJournal, 2014;2014:972501.
    PMID: 24895684 DOI: 10.1155/2014/972501
    The coating of an active drug, 6-mercaptopurine, into the iron oxide nanoparticles-polyethylene glycol (FNPs-PEG) in order to form a new nanocomposite, FPEGMP-2, was accomplished using coprecipitation technique. The resulting nanosized with a narrow size distribution magnetic polymeric particles show the superparamagnetic properties with 38.6 emu/g saturation magnetization at room temperature. Fourier transform infrared spectroscopy and the thermal analysis study supported the formation of the nanocomposite and the enhancement of thermal stability in the resulting nanocomposite comparing with its counterpart in free state. The loading of 6-mercaptopurine (MP) in the FPEGMP-2 nanocomposite was estimated to be about 5.6% and the kinetic experimental data properly correlated with the pseudo-second order model. Also, the release of MP from the FPEGMP-2 nanocomposite shows the sustained release manner which is remarkably lower in phosphate buffered solution at pH 7.4 than pH 4.8, due to different release mechanism. The maximum percentage release of MP from the nanocomposite reached about 60% and 97% within about 92 and 74 hours when exposed to pH 7.4 and 4.8, respectively.
    Matched MeSH terms: Cell Survival/drug effects
  10. Genotoxicity evaluation of dental restoration nanocomposite using comet assay and chromosome aberration test
    Musa M, Ponnuraj KT, Mohamad D, Rahman IA
    Nanotechnology, 2013 Jan 11;24(1):015105.
    PMID: 23221152 DOI: 10.1088/0957-4484/24/1/015105
    Nanocomposite is used as a dental filling to restore the affected tooth, especially in dental caries. The dental nanocomposite (KelFil) for tooth restoration used in this study was produced by the School of Dental Sciences, Universiti Sains Malaysia, Malaysia and is incorporated with monodispersed, spherical nanosilica fillers. The aim of the study was to determine the genotoxic effect of KelFil using in vitro genotoxicity tests. The cytotoxicity and genotoxicity of KelFil was evaluated using MTT assay, comet assay and chromosome aberration tests with or without the addition of a metabolic activation system (S9 mix), using the human lung fibroblast cell line (MRC-5). Concurrent negative and positive controls were included. In the comet assay, no comet formation was found in the KelFil groups. There was a significant difference in tail moment between KelFil groups and positive control (p < 0.05). Similarly, no significant aberrations in chromosomes were noticed in KelFil groups. The mitotic indices of treatment groups and negative control were significantly different from positive controls. Hence, it can be concluded that the locally produced dental restoration nanocomposite (KelFil) is non-genotoxic under the present test conditions.
    Matched MeSH terms: Cell Survival/drug effects
  11. Size-related assessment on viability and insulin secretion of caprine islets in vitro
    Vakhshiteh F, Allaudin ZN, Mohd Lila MA, Hani H
    Xenotransplantation, 2013 02 14;20(2):82-8.
    PMID: 23406308 DOI: 10.1111/xen.12023
    BACKGROUND: The successful isolation, purification, and culture of caprine islets has recently been reported. The present study shows arange of size distribution in caprine islet diameter from 50 to 250 μm, in which 80% of the total islet yield was comprised of small islets.

    METHODS: Caprine islets were isolated and purified. Islets were handpicked and the diameter of the islets was recorded using light microscopy. Viablility of the islets was analyzed by confocal microscopy. Insulin secretion assay was carried out and analyzed by ELISA.

    RESULTS: When tested at 48 h after isolation, these small islets were 29.3% more viable compared to the large-sized islets. Large islets showed a high ratio (P 

    Matched MeSH terms: Cell Survival/physiology
  12. Characterization and cytotoxicity of nanostructured lipid carriers formulated with olive oil, hydrogenated palm oil, and polysorbate 80
    How CW, Rasedee A, Abbasalipourkabir R
    IEEE Trans Nanobioscience, 2013 Jun;12(2):72-8.
    PMID: 23268387 DOI: 10.1109/TNB.2012.2232937
    Nanostructured lipid carriers (NLC) composed of solid and liquid lipids, and surfactants are potentially good colloidal drug carriers. Before NLC can be used as drug carriers, the cytotoxicity of their components must be ascertained. The cytotoxicity of solid lipids (trilaurin, palmitin, docosanoid acid, and hydrogenated palm oil [HPO]) and surfactants (Polysorbate 20, 80, and 85) were determined on BALB/c 3T3 cells. The HPO and Polysorbate 80 were least cytotoxic and used with olive oil in the formulation of NLC. The particle size, polydispersity index, zeta potential, specific surface area, and crystallinity index of the NLC were 61.14 nm, 0.461, -25.4 mV, and 49.07 m(2) and 27.12% respectively, while the melting point was 4.3 °C lower than of HPO. Unlike in serum-free, NLC incubated in fetal bovine serum-supplemented medium did not show particle growth, suggesting that serum proteins in medium inhibit nanoparticles aggregation. The study also showed that NLC was less toxic to BALB/c 3T3 cells than Polysorbate 80. Thus, NLC with olive oil, HPO, and Polysorbate 80 as components are potentially good drug carriers with minimal cytotoxicity on normal cells.
    Matched MeSH terms: Cell Survival/drug effects
  13. Antioxidant and cytoprotective effects of an ethanol extract of Acalypha wilkesiana var. macafeana from Malaysia
    Din WM, Chu J, Clarke G, Jin KT, Bradshaw TD, Fry JR, et al.
    Nat Prod Commun, 2013 Mar;8(3):375-80.
    PMID: 23678815
    In the annals of biomedical theory perhaps no single class of natural product has enjoyed more ingenious speculation than antioxidants formally aimed at counteracting oxidative insults which are involved in the pathophysiology of Alzheimer's and Parkinson's disease, cancer, amyotrophic lateral sclerosis, skin ageing and wound healing. In pursuing our study of Malaysian traditional medicines with antioxidant properties, we became interested in Acalypha wilkesiana var. macafeana hort., used traditionally to heal wounds. To examine whether Acalypha wilkesiana var. macafeana hort. could suppress oxidation an ethanol extract was tested by conventional chemical in vitro assays i.e., ferric reducing antioxidant potential assay (FRAP), DPPH scavenging assay and beta-carotene bleaching (BCB) assay. To explore whether Acalypha wilkesiana var. macafeana hort. protected cells against oxidative injuries, we exposed human hepatocellular liver carcinoma (HepG2) cells to tert-butylhydroperoxide (t-BHP). In all the aforementioned experiments, the ethanol extracts elicited potent antioxidant and cytoprotective activities. To gain a better understanding of the phytochemical nature of the antioxidant principle involved, five fractions (F1-F5) obtained from the ethanol extract were tested using FRAP, DPPH and BCB assays. Our results provided evidence that F5 was the most active fraction with antioxidant potentials equal to 2.090 +/- 0.307 microg/mL, 0.532 +/- 0.041 microg/mL, 0.032 +/- 0.025 microg/mL in FRAP, DPPH and BCB assay, respectively. Interestingly, F5 protected HepG2 against t-BHP oxidative insults. To further define the chemical identity of the antioxidant principle, we first performed a series of phytochemical tests, followed by liquid-chromatography and mass spectrometry (LC/MS) profiling which showed that the major compound contained in F5 was geraniin. To the best of our knowledge, this is the first report showing that the wound healing property of Acalypha wilkesiana var. macafeana hort. is mediated by a geraniin containing extract. Furthermore, our data leads us to conclude that geraniin could be used as a potential pharmaceutical and/or cosmetic topical agent.
    Matched MeSH terms: Cell Survival/drug effects
  14. New bioactive secondary metabolites from Bornean red alga, Laurencia similis (Ceramiales)
    Kamada T, Vairappan CS
    Nat Prod Commun, 2013 Mar;8(3):287-8.
    PMID: 23678792
    A Bomean red algal population of Laurencia similis Nam et Saito was analyzed for its secondary metabolite composition. Seven compounds were identified: ent-1(10)-aristolen-9beta-ol (1), (+)-aristolone (2), axinysone B (3), 9-aristolen-1alpha-ol (4), 2,3,5,6-tetrabromoindole (5), 1-methyl-2,3,5,6-tetrabromoindole (6), and 1-methyl-2,3,5-tribromoindole (7). Compound 1 was identified as a new optical isomer of 1(10)-aristolen-9beta-ol. Compounds 1, 4 and 5 exhibited good antibacterial activity against antibiotic resistant clinical bacteria and cytotoxic effects against selected cancer cell lines.
    Matched MeSH terms: Cell Survival/drug effects
  15. Anti-proliferative and anti-invasive properties of a purified fraction from Streptomyces sp. H7372
    Yip WK, Cheenpracha S, Chang LC, Ho CC, Seow HF
    Int J Oncol, 2010 Nov;37(5):1229-41.
    PMID: 20878070
    Secondary metabolites from actinomycetes especially the genus Streptomyces may be one of the most important sources for novel anticancer agents. A purified fraction from a novel actinomycete strain, Streptomyces sp. H7372, was elucidated in breast cancer cells. We have isolated three purified fractions from a novel strain, Streptomyces sp. H7372. One of the fractions, designated as 31-2, exhibited the strongest growth-inhibitory effect and thereby was selected for further studies. 31-2 exerted a growth-inhibitory effect on a panel of 15 human cancer and 2 non-malignant cell lines. In MCF-7 and MDA-MB-231 breast cancer cells, 31-2 induced a cytostatic (anti-proliferative) effect without causing cytotoxicity (cell death). Our data suggest that the cytostasis resulted from cell cycle arrest at the G1 phase in MCF-7 cells and at the S phase in MDA-MB-231 cells. Western blot analysis demonstrated a modulation of phosphorylation of the Rb and CDC2 proteins and of CDK4, cyclin D1 and cyclin D3 in the 31-2-treated breast cancer cell lines. The protein levels of CDK2, CDK6, and PCNA were not affected by 31-2 treatment. 31-2 also exhibited an anti-invasive effect in MDA-MB-231 cells. However, this effect is not attributed to the modulation of proteolytic activity in MDA-MB-231 cells as the enzymatic degradation of type IV collagen was not affected by 31-2. The 31-2 is a potent cytostatic and anti-invasive agent and modulates the cell cycle pathway. Together, these results will have important implications in searching for novel approaches to treat cancer.
    Matched MeSH terms: Cell Survival/drug effects
  16. Modulation of the benzene metabolite hydroquinone induced toxicity: evidence for an important role of fau
    Inayat-Hussain SH, Ibrahim HA, Siew EL, Rajab NF, Chan KM, G T Williams, et al.
    Chem Biol Interact, 2010 Mar 19;184(1-2):310-2.
    PMID: 20025857 DOI: 10.1016/j.cbi.2009.12.009
    Matched MeSH terms: Cell Survival/drug effects
  17. Erythrocarpines A-E, new cytotoxic limonoids from Chisocheton erythrocarpus
    Awang K, Lim CS, Mohamad K, Morita H, Hirasawa Y, Takeya K, et al.
    Bioorg Med Chem, 2007 Sep 1;15(17):5997-6002.
    PMID: 17576066
    Five new cytotoxic limonoids, erythrocarpines A-E (1-5), were isolated from the bark of Chisocheton erythrocarpus Hiern. Chemical structures, stereochemistry, and conformation were fully elucidated and characterized by 2D NMR, MS, and computational methods.
    Matched MeSH terms: Cell Survival/drug effects
  18. Cryopreservation of scalps of Malaysian bananas using a pre-growth method
    Sipen P, Anthony P, Davey MR
    Cryo Letters, 2011 May-Jun;32(3):197-205.
    PMID: 21766149
    The effect of preculture with different sugars and mannitol on cryopreservation of scalps of the banana (Musa) cvs. Pisang Mas, Pisang Nangka, Pisang Berangan and Pisang Awak was investigated. Scalps (0.3 square cm) were precultured on semi-solid MS-based medium, containing 0.4 or 0.5 M sucrose, glucose, fructose, trehalose or mannitol, for 14 days under a 16 h light and 8 h dark photoperiod prior to rapid cooling and storage in liquid nitrogen. Explants were rewarmed rapidly in a water bath at 40 degree C for 1 min, followed by recovery on two layers of sterile filter paper overlaying 25 ml aliquots of semi-solid MS-based medium with 5 mg per liter benzylaminopurine, 0.2 mg per liter indole acetic acid and 10 mg per liter ascorbic acid (PM8 medium) for 2 days in the dark. Subsequently, scalps were transferred onto 25 ml aliquots of semi-solid PM8 medium and incubated in the dark for 1 week prior to incubation in the light. Shoot regeneration from 5 - 48 percent of cryopreserved scalps of all the banana cvs., was observed only following preculture with 0.4 or 0.5 M glucose or fructose, and with 0.4 M trehalose for the cvs. Pisang Berangan and Pisang Awak. Preculture with 0.4 M glucose resulted in maximum shoot regeneration of cryopreserved scalps of 10 percent, 13 percent, 42 percent and 48 percent for the cvs. Pisang Mas, Pisang Nangka, Pisang Berangan and Pisang Awak, respectively. Concentrations of 0.5 M trehalose, or 0.4 and 0.5 M sucrose or mannitol were extremely toxic to scalps of all the cvs. investigated.
    Matched MeSH terms: Cell Survival/drug effects
  19. Enhancement of viability of a probiotic Lactobacillus strain for poultry during freeze-drying and storage using the response surface methodology
    Khoramnia A, Abdullah N, Liew SL, Sieo CC, Ramasamy K, Ho YW
    Anim Sci J, 2011 Feb;82(1):127-35.
    PMID: 21269371 DOI: 10.1111/j.1740-0929.2010.00804.x
    A rotatable central composite design (CCD) was used to study the effect of cryoprotectants (skim milk, sucrose and lactose) on the survival rate of a probiotic Lactobacillus strain, L. reuteri C10, for poultry, during freeze-drying and storage. Using response surface methodology, a quadratic polynomial equation was obtained for response value by multiple regression analyses: Y = 8.59546-0.01038 X(1)-0.09382 X(2)-0.07771 X(3)-0.054861 X(1)(2)-0.04603 X(3)(2)-0.10938 X(1)X(2). Based on the model predicted, sucrose exerted the strongest effect on the survival rate. At various combinations of cryoprotectants, the viability loss of the cells after freeze-drying was reduced from 1.65 log colony forming units (CFU)/mL to 0.26-0.66 log CFU/mL. The estimated optimum combination for enhancing the survival rate of L. reuteri C10 was 19.5% skim milk, 1% sucrose and 9% lactose. Verification experiments confirmed the validity of the predicted model. The storage life of freeze-dried L. reuteri C10 was markedly improved when cryoprotectants were used. At optimum combination of the cryoprotectants, the survival rates of freeze-dried L. reuteri C10 stored at 4°C and 30°C for 6 months were 96.4% and 73.8%, respectively. Total viability loss of cells which were not protected by cryoprotectants occurred after 12 and 8 weeks of storage at 4°C and 30°C, respectively.
    Matched MeSH terms: Cell Survival*
  20. Cryopreservation of whole seeds and excised embryonic axes of Citrus suhuiensis cv. limau langkat in accordance to their desiccation sensitivity
    Makeen MA, Noor NM, Dussert S, Clyde MM
    Cryo Letters, 2005 Jul-Aug;26(4):259-68.
    PMID: 19827255
    Following the investigation of desiccation sensitivity and freezing tolerance of the whole seed of Citrus suhuiensis cv. limau langkat, desiccation sensitivity and cryopreservation of the excised embryonic axes from the seeds of the same species were examined. Three drying conditions were employed: desiccation by equilibrium for the whole seeds and desiccation in laminar airflow and over silica gel for the excised embryonic axes. The relevance of desiccation sensitivity (WC50) to cryopreservation of whole seeds and excised axes was investigated. High desiccation tolerance (WC50 = 0.034 g H2O x g(-1)dw) was acquired for axes desiccated with faster dehydration rate (1.5 g x g(-1) x h(-1)) in laminar airflow compared to substantially lower desiccation tolerance (WC50 = 0.132 and 0.110 g H2O x g(-1)dw) acquired under slower dehydration rates (1.0 and 0.005 g x g(-1) x h(-1)) for axes desiccated over silica gel and whole seeds desiccated by equilibrium respectively. While few whole seeds (8.3%) survived freezing, high recovery percentages of axes (83.3% and 62.2%) after freezing were obtained under laminar airflow and silica gel drying conditions respectively. Irrespective of the drying method employed, axes survival percentages after exposure to LN temperature commensurate with the desiccation sensitivity pattern. For the whole seeds, a factor other than desiccation sensitivity that limits the tolerance to exposure to LN temperature seems to exist and still needs to be defined.
    Matched MeSH terms: Cell Survival/physiology
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