Displaying publications 41 - 60 of 679 in total

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  1. Goniothalamin selectively induces apoptosis on human hepatoblastoma cells through caspase-3 activation
    Al-Qubaisi M, Rosli R, Subramani T, Omar AR, Yeap SK, Ali AM, et al.
    Nat Prod Res, 2013;27(23):2216-8.
    PMID: 23767409 DOI: 10.1080/14786419.2013.800979
    Goniothalamin is a biologically active styrylpyrone derivative isolated from various Goniothalamus species. The ability of goniothalamin to induce apoptosis via caspase-3 activation against hepatoblastoma (HepG2) and normal liver cells (Chang cells) was studied using morphological and biochemical evaluations. HepG2 and Chang cells were treated with goniothalamin for 72 h and analysed by TUNEL and Annexin-V/PI staining. Furthermore, the post-mitochondrial caspase-3 was quantified using ELISA. In view of our results, goniothalamin induced apoptosis on treated cells via alteration of cellular membrane integrity and cleavage of DNA. On the other hand, post-mitochondrial caspase-3 activity was significantly elevated in HepG2 cells treated with goniothalamin after 72 h. These findings suggest that goniothalamin induced apoptosis on HepG2 liver cancer cells via induction of caspase-3 with less sensitivity on the cell line of Chang cells.
    Matched MeSH terms: Cells, Cultured
  2. Fulltext Cytotoxic Effects of Betel Quid and Areca Nut Aqueous Extracts on Mouse Fibroblast, Human Mouth-Ordinary-Epithelium 1 and Human Oral Squamous Cell Carcinoma Cell Lines
    Al-Tayar BA, Ahmad A, Yusoff ME, Abdullah SF, Mohamad NK, Md Hashim SN, et al.
    Asian Pac J Cancer Prev, 2020 Apr 01;21(4):1005-1009.
    PMID: 32334462 DOI: 10.31557/APJCP.2020.21.4.1005
    BACKGROUND: Betel quid chewing is more common among the older generation in rural areas of Malaysia. Oral cancer in Asia has been associated with the habit of chewing betel quid and areca nut.

    OBJECTIVE:   This study aims to investigate the cytotoxic effects of betel quid and areca nut extracts on the fibroblast (L929), mouth-ordinary-epithelium 1 (MOE1) and oral squamous cell carcinoma (HSC-2) cell lines.

    METHODS: L929, MOE1 and HSC-2 cells were treated with 0.1, 0.2 and 0.4 g/ml of betel quid and areca nut extracts for 24, 48 and 72 h. MTT assay was performed to assess the cell viability.

    RESULTS: Both extracts, regardless of concentration, significantly reduced the cell viability of L929 compared with the control (P<0.05). Cell viability of MOE1 was significantly enhanced by all betel quid concentrations compared with the control (P<0.05). By contrast, 0.4 g/ml of areca nut extract significantly reduced the cell viability of MOE1 at 48 and 72 h of incubation. Cell viability of HSC-2 was significantly lowered by all areca nut extracts, but 0.4 g/ml of betel quid significantly increased the cell viability of HSC-2 (P<0.05).

    CONCLUSION: Areca nut extract is cytotoxic to L929 and HSC-2, whereas the lower concentrations of areca nut extract significantly increased the cell viability of MOE1 compared to the higher concentration and control group. Although betel quid extract is cytotoxic to L929, the same effect is not observed in MOE1 and HSC-2 cell lines. Further investigations are needed to clarify the mechanism of action.
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    Matched MeSH terms: Cells, Cultured
  3. Fulltext Evaluation of the genotoxicity of zerumbone in cultured human peripheral blood lymphocytes
    Al-Zubairi AS, Abdul AB, Syam MM
    Toxicol In Vitro, 2010 Apr;24(3):707-12.
    PMID: 20123012 DOI: 10.1016/j.tiv.2010.01.011
    The chromosomal aberrations (CA) assay and micronucleus (MN) test were employed to investigate the effect in vitro of zerumbone (ZER) on human chromosomes. ZER is a sesquiterpene compound isolated from the rhizomes of wild ginger, Zingiber zerumbet Smith. The rhizomes of the plant are employed as a traditional medicine for some ailments and as condiments. ZER has been shown to have anti-cancer and apoptosis-inducing properties against various human tumour cells. It has also been shown to be active in vivo against a number of induced malignancies. Studies on ZER genotoxicity in cultured human peripheral blood lymphocytes (PBL) have not been reported so far. Therefore, the present study was undertaken to investigate the ability of ZER to induce chromosomal aberrations and micronuclei formation in human lymphocytes in vitro. Human blood samples were obtained from four healthy, non-smoking males aged 25-35years. Cultures were exposed to the drug for 48h at four final concentrations: 10, 20, 40 and 80 microM. Mitomycin C (MMC) was used as a positive control. The results of chromosomal aberrations assay showed that ZER was not clastogenic, when compared to untreated control, meanwhile MN test results showed a dose-dependent increase in MN formation. The overall clastogenic effect of ZER on human PBL was statistically not significant. In conclusion, ZER is a cytotoxic but not a clastogenic substance in human PBL.
    Matched MeSH terms: Cells, Cultured
  4. Apoptosis induction, cell cycle arrest and in vitro anticancer activity of gonothalamin in a cancer cell lines
    Alabsi AM, Ali R, Ali AM, Al-Dubai SA, Harun H, Abu Kasim NH, et al.
    Asian Pac J Cancer Prev, 2012;13(10):5131-6.
    PMID: 23244123
    Cancer is one of the major health problems worldwide and its current treatments have a number of undesired adverse side effects. Natural compounds may reduce these. Currently, a few plant products are being used to treat cancer. In this study, goniothalamin, a natural occurring styryl-lactone extracted from Goniothalamus macrophyllus, was investigated for cytotoxic properties against cervical cancer (HeLa), breast carcinoma (MCF-7) and colon cancer (HT29) cells as well as normal mouse fibroblast (3T3) using MTT assay. Fluorescence microscopy showed that GTN is able to induce apoptosis in HeLa cells in a time dependent manner. Flow cytometry further revealed HeLa cells treated with GTN to be arrested in the S phase. Phosphatidyl serine properties present during apoptosis enable early detection of the apoptosis in the cells. Using annexin V/PI double staining it could be shown that GTN induces early apoptosis on HeLa cells after 24, 48 and 72 h. It could be concluded that goniothalamin showing a promising cytotoxicity effect against several cancer cell lines including cervical cancer cells (HeLa) with apoptosis as the mode of cell death induced on HeLa cells by Goniothalamin was.
    Matched MeSH terms: Cells, Cultured
  5. Fulltext RNA-Seq analysis revealed genes associated with UV-induced cell necrosis through MAPK/TNF-α pathways in human dermal fibroblast cells as an inducer of premature photoaging
    Alafiatayo AA, Lai KS, Ahmad S, Mahmood M, Shaharuddin NA
    Genomics, 2020 01;112(1):484-493.
    PMID: 30946891 DOI: 10.1016/j.ygeno.2019.03.011
    Exposing the skin to solar UV radiation induces cascades of signaling pathways and biological alterations such as redox imbalance, suppression of antioxidant genes and programmed cell death. Therefore, the aim of this study was to use RNA-Seq to unravel the effects of UV radiation on Normal Human Adult Fibroblast cells (NHDF). Cells were exposed to UV (20 mJ/cm2 for 3 mins) and incubated for 24 h. Total mRNA from the cells generated libraries of 72,080,648 and 40,750,939 raw reads from UV-treated and control cells respectively. Of the differentially expressed genes (DEGs) produced 2,007 were up-regulated and 2,791 were down-regulated (fold change ≥2, p 
    Matched MeSH terms: Cells, Cultured
  6. Pluronic-F127 composite film loaded with erythromycin for wound application: formulation, physicomechanical and in vitro evaluations
    Alavi T, Rezvanian M, Ahmad N, Mohamad N, Ng SF
    Drug Deliv Transl Res, 2019 04;9(2):508-519.
    PMID: 29181832 DOI: 10.1007/s13346-017-0450-z
    Composite film dressings composed of pluronic F127 (PL)-pectin (PC) and pluronic (PL) F127-gelatin (GL) were investigated as potential drug delivery system for wound healing. Composite films were solvent cast by blending PL with PC or GL in different ratios using glycerol (2.5%) as plasticizer. Erythromycin (ER) (0.1%) was incorporated in films as model hydrophobic antibiotic. The optimized composite films were characterized for physical appearance, morphology, mechanical profile, and thermal behavior. In addition, drug release, antibacterial activity, and cytocompatibility of the films were investigated to assess their potential as drug delivery system. The composite films exhibited excellent wound dressing characters in terms of appearance, stability, and mechanical profile. Moreover, ER-loaded composite films released ER in controlled manner, exhibited antibacterial activity against Staphylococcus aureus, and were non-toxic to human skin fibroblast. These findings demonstrate that these composite films hold the potential to be formulated as antibacterial wound dressing.
    Matched MeSH terms: Cells, Cultured
  7. A critical role of TRPM2 channel in Aβ42 -induced microglial activation and generation of tumor necrosis factor-α
    Alawieyah Syed Mortadza S, Sim JA, Neubrand VE, Jiang LH
    Glia, 2018 03;66(3):562-575.
    PMID: 29143372 DOI: 10.1002/glia.23265
    Amyloid β (Aβ)-induced neuroinflammation plays an important part in Alzheimer's disease (AD). Emerging evidence supports a role for the transient receptor potential melastatin-related 2 (TRPM2) channel in Aβ-induced neuroinflammation, but how Aβ induces TRPM2 channel activation and this relates to neuroinflammation remained poorly understood. We investigated the mechanisms by which Aβ42 activates the TRPM2 channel in microglial cells and the relationships to microglial activation and generation of tumor necrosis factor-α (TNF-α), a key cytokine implicated in AD. Exposure to 10-300 nM Aβ42 induced concentration-dependent microglial activation and generation of TNF-α that were ablated by genetically deleting (TRPM2 knockout ;TRPM2-KO) or pharmacologically inhibiting the TRPM2 channel, revealing a critical role of this channel in Aβ42 -induced microglial activation and generation of TNF-α. Mechanistically, Aβ42 activated the TRPM2 channel via stimulating generation of reactive oxygen species (ROS) and activation of poly(ADPR) polymerase-1 (PARP-1). Aβ42 -induced generation of ROS and activation of PARP-1 and TRPM2 channel were suppressed by inhibiting protein kinase C (PKC) and NADPH oxidases (NOX). Aβ42 -induced activation of PARP-1 and TRPM2 channel was also reduced by inhibiting PYK2 and MEK/ERK. Aβ42 -induced activation of PARP-1 was attenuated by TRPM2-KO and moreover, the remaining PARP-1 activity was eliminated by inhibiting PKC and NOX, but not PYK2 and MEK/ERK. Collectively, our results suggest that PKC/NOX-mediated generation of ROS and subsequent activation of PARP-1 play a role in Aβ42 -induced TRPM2 channel activation and TRPM2-dependent activation of the PYK2/MEK/ERK signalling pathway acts as a positive feedback to further facilitate activation of PARP-1 and TRPM2 channel. These findings provide novel insights into the mechanisms underlying Aβ-induced AD-related neuroinflammation.
    Matched MeSH terms: Cells, Cultured
  8. Fulltext Ultrastructure of Felis catus whole fetus (Fcwf-4) cell culture following infection with feline coronavirus
    Alazawy A, Arshad SS, Bejo MH, Omar AR, Tengku Ibrahim TA, Sharif S, et al.
    J Electron Microsc (Tokyo), 2011;60(4):275-82.
    PMID: 21593079 DOI: 10.1093/jmicro/dfr031
    Feline coronavirus (FCoV) consists of two biotypes based on their growth in cell culture and their antigenicity. Infections with FCoV are highly prevalent in the cat population worldwide. In this study, Felis catus whole fetus (Fcwf-4)cell culture was infected with FCoV UPM11C/08. Virus multiplication in cell culture was monitored and examined under the transmission electron microscope. The virus particles revealed the characteristic morphology of feline FCoV represented by envelope viruses surrounded by peplomers. Virus attachment and entry into the cell occurred 15 h post-infection (pi), and the myriad of virus particles were observed both extracellularly and intracellularly after 48 h pi. Thereafter, intracellular virus particles were observed to be present in vacuoles or present freely in the cytoplasm.
    Matched MeSH terms: Cells, Cultured/ultrastructure; Cells, Cultured/virology
  9. Cell based therapy for osteoarthritis in a sheep model: gross and histological assessment
    Alfaqeh H, Norhamdan MY, Chua KH, Chen HC, Aminuddin BS, Ruszymah BH
    Med J Malaysia, 2008 Jul;63 Suppl A:37-8.
    PMID: 19024972
    This study was to determine if autologous bone marrow mesenchymal stem cells (BMSCs) cultured in chondrogenic medium could repair surgically induced osteoarthritis. Sheep BMSCs were cultured in medium containing 5ng/ml TGFbeta3 + 50ng/ml IGF-1 for three weeks. The cultured cells were then suspended at density of 2x10(6) cell/ml and injected intraarticularly into the osteoarthritic knee joint. After six weeks, the distal head of the femur and the proximal tibial plateau were removed and stained with H&E. The results indicated that knee joints treated with autologous BMSCs cultured in chondrogenic medium showed clear evidence of articular cartilage regeneration in comparison with other groups.
    Matched MeSH terms: Cells, Cultured
  10. Helicobacter pylori: molecular detection of vacA gene and vacuolating activity in human gastric adenocarcinoma cells
    Alfizah H, Noraziah MZ, Chao MY, Rahman MM, Ramelah M
    Clin Ter, 2013;164(4):301-5.
    PMID: 24045512 DOI: 10.7417/CT.2013.1577
    Helicobacter pylori strains secrete a vacuolating cytotoxin (VacA), plays an important role for the development of peptic ulcer disease and gastro-duodenal diseases. vacA gene is responsible to regulate the activity of the vacuolating cytotoxin. The objective of this study was molecular detection of vacA gene and observes the vacuolating activity on human gastric adenocarcinoma (AGS) cells.
    Matched MeSH terms: Tumor Cells, Cultured
  11. Fulltext Inhibition of dengue virus entry and multiplication into monocytes using RNA interference
    Alhoot MA, Wang SM, Sekaran SD
    PLoS Negl Trop Dis, 2011 Nov;5(11):e1410.
    PMID: 22140591 DOI: 10.1371/journal.pntd.0001410
    Dengue infection ranks as one of the most significant viral diseases of the globe. Currently, there is no specific vaccine or antiviral therapy for prevention or treatment. Monocytes/macrophages are the principal target cells for dengue virus and are responsible for disseminating the virus after its transmission. Dengue virus enters target cells via receptor-mediated endocytosis after the viral envelope protein E attaches to the cell surface receptor. This study aimed to investigate the effect of silencing the CD-14 associated molecule and clathrin-mediated endocytosis using siRNA on dengue virus entry into monocytes.
    Matched MeSH terms: Cells, Cultured
  12. Antitumour-promoting and antitumour activities of the crude extract from the leaves of Juniperus chinensis
    Ali AM, Mackeen MM, Intan-Safinar I, Hamid M, Lajis NH, el-Sharkawy SH, et al.
    J Ethnopharmacol, 1996 Sep;53(3):165-9.
    PMID: 8887024
    Matched MeSH terms: Cells, Cultured; Tumor Cells, Cultured
  13. Cytotoxicity and electron microscopy of cell death induced by goniothalamin
    Ali AM, Mackeen MM, Hamid M, Aun QB, Zauyah Y, Azimahtol HL, et al.
    Planta Med, 1997 Feb;63(1):81-3.
    PMID: 9063100
    The cytotoxicity of goniothalamin was found to be strong towards both cancerous (HGC-27, MCF-7, PANC-1, HeLa), and non-cancerous (3T3) cell lines, especially in cases of dividing cells. Drug exposure studies indicated that the cytotoxic action of goniothalamin was time- and dose-dependent. At the ultrastructural level, goniothalamin-induced cytotoxicity revealed a necrotic mode of cell death towards MCF-7 cells.
    Matched MeSH terms: Tumor Cells, Cultured
  14. Evaluation of Ultra-Microscopic Changes and Proliferation of Apoptotic Glioblastoma Multiforme Cells Induced by Velogenic Strain of Newcastle Disease Virus AF2240
    Ali- Saeed R, Alabsi AM, Ideris A, Omar AR, Yusoff K, Ali AM
    Asian Pac J Cancer Prev, 2019 Mar 26;20(3):757-765.
    PMID: 30909682
    Aim: Newcastle disease virus (NDV) is a member of genus Avulavirus within the family Paramyxoviridae. Interest
    of using NDV as an anticancer agent has arisen from its ability to kill tumor cells with limited toxicity to normal cells.
    Methods: In this investigation, the proliferation of brain tumor cell line, glioblastoma multiform (DBTRG.05MG)
    induced by NDV strain AF2240 was evaluated in-vitro, by using MTT proliferation assay. Furthermore, Cytological
    observations were studied using fluorescence microscopy and transmission electron microscopy, DNA laddering in
    agarose gel electrophoresis assay used to detect the mode of cell death and analysis of the cellular DNA content by
    flowcytometery. Results: MTT proliferation assay, Cytological observations using fluorescence microscopy and
    transmission electron microscopy show the anti-proliferation effect and apoptogenic features of NDV on DBTRG.05MG.
    Furthermore, analysis of the cellular DNA content showed that there was a loss of treated cells in all cell cycle phases
    (G1, S and G2/M) accompanied with increasing in sub-G1 region (apoptosis peak). Conclusion: It could be concluded
    that NDV strain AF2240 is a potent antitumor agent that induce apoptosis and its cytotoxicity increasing while increasing
    of time and virus titer.
    Matched MeSH terms: Tumor Cells, Cultured
  15. Cytotoxic effects of commercial wheatgrass and fiber towards human acute promyelocytic leukemia cells (HL60)
    Alitheen NB, Oon CL, Keong YS, Chuan TK, Li HK, Yong HW
    Pak J Pharm Sci, 2011 Jul;24(3):243-50.
    PMID: 21715255
    Cytotoxicity, the possible selective activity upon HL60 as well as the anti-proliferation effect of local health supplement wheatgrass and mixture of fibers were investigated in vitro using various cancerous cell line and normal blood cell culture. The IC(50) of wheatgrass-treated HL60 (17.5 ± 1.1, 12.5 ± 0.3, and 16 ± 0.5 microgram/ml for 24, 48 and 72 h, respectively) and fibers-treated HL60 (86.0 ± 5.5, 35.0 ± 2.5, and 52.5 ± 4.5 microgram/ml for 24, 48 and 72 h, respectively) showed that both extracts possessed optimum effect after 48 hours of treatment. No significant cytotoxic effect was observed on other type of cells. For trypan blue dye exclusion method, wheatgrass reduced the number of viable cells by 13.5% (±1.5), 47.1% (±3.6), and 64.9% (±2.7) after 24, 48 and 72 h exposure, respectively. Mixture of fibers reduced the number of viable cells by 36.4% (±2.3), 57.1% (±3.1), and 89.0% (±3.4) after 24, 48 and 72 h exposure, respectively, indicated that necrosis is also an alternative to the apoptotic mechanism of cell death. Annexin-V/propidium iodide staining revealed that both extracts induced apoptosis where early apoptosis had been detected concurrently with the reduction of percentage of cell viability. Cell cycle analysis revealed that in HL60, the percentage of apoptosis increased with time (wheatgrass: 16.0% ± 2.4, 45.3% ± 3.4 and 39.6% ± 4.1; mixture of fibers: 14.6% ± 1.8, 45.4% ± 2.3 and 45.9% ± 1.2) after exposure for 24, 48 and 72 h, respectively at the concentration of 100 microgram/ml and showed optimum effect at 48 hours. Thus, these health products can be a potential alternative supplement for leukaemia patients.
    Matched MeSH terms: Cells, Cultured
  16. Fulltext Establishment of an in vitro system representing the chicken gut-associated lymphoid tissue
    Alitheen NB, McClure SJ, Yeap SK, Kristeen-Teo YW, Tan SW, McCullagh P
    PLoS One, 2012;7(11):e49188.
    PMID: 23185307 DOI: 10.1371/journal.pone.0049188
    The bursa of Fabricius is critical for B cell development and differentiation in chick embryos. This study describes the production in vitro, from dissociated cell suspensions, of cellular agglomerates with functional similarities to the chicken bursa. Co-cultivation of epithelial and lymphoid cells obtained from embryos at the appropriate developmental stage regularly led to agglomerate formation within 48 hours. These agglomerates resembled bursal tissue in having lymphoid clusters overlaid by well organized epithelium. Whereas lymphocytes within agglomerates were predominantly Bu-1a(+), a majority of those emigrating onto the supporting membrane were Bu-1a(-) and IgM(+). Both agglomerates and emigrant cells expressed activation-induced deaminase with levels increasing after 24 hours. Emigrating cells were actively proliferating at a rate in excess of both the starting cell population and the population of cells remaining in agglomerates. The potential usefulness of this system for investigating the response of bursal tissue to avian Newcastle disease virus (strain AF2240) was examined.
    Matched MeSH terms: Cells, Cultured
  17. Fulltext Acute toxicity evaluation, antibacterial, antioxidant and immunomodulatory effects of Melastoma malabathricum
    Alnajar ZA, Abdulla MA, Ali HM, Alshawsh MA, Hadi AH
    Molecules, 2012;17(3):3547-59.
    PMID: 22433579 DOI: 10.3390/molecules17033547
    Melastoma malabathricum (MM) is a well-known plant in Malaysian traditional medicine, locally known as senduduk. Its ethanol and aqueous extracts have been used in the present investigation to study the immunomodulatory role on human peripheral blood mononuclear cell (PBMC), and the DPPH, ABTS and FRAP free radical scavenging activities were also measured. Total flavonoids and total phenolic contents were assayed and the antibacterial effect was tested against four species of bacteria; two Gram-positive (Staphylococcus aureus and Streptococcus agalactiae) and two Gram-negative (Escherichia coli and Klebsilla pneumonia). The tests were carried out using the disc diffusion, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) methods. Moreover, the acute toxicity was evaluated in vivo on the ethanol extract of MM to establish its safety when administered orally. In our results, both extracts of MM showed abilities to scavenge DPPH and ABTS free radicals, IC(50) values: (11.599 ± 0.84, 10.573 ± 0.58 µmol/L) and (62.657 ± 0.78, 63.939 ± 0.48 µmol/L) for ethanol and aqueous extracts respectively. Indeed the ethanol extract evidenced high phenolic content (384.33 ± 0.005 mg/g), flavonoids contents (85.8 ± 0.009 mg/g) and ferric reducing antioxidant power (33,590 ± 0.038 mmol/g), with high activity against S. aureus and S. agalactiae (11 ± 0.3 and 12 ± 0.6 mm inhibition zones). Likewise, the percentage of peripheral blood mononuclear cells (PBMC) viability was increased in response to MM, IC(50) values (1.781 ± 1.2 and 6.545 ± 0.93 µg/mL) for ethanol and aqueous extracts, respectively. In addition, our results showed that the MM extract is safe even at a high dose of 5,000 mg/kg and has no oral toxicity. These findings suggest the excellent medicinal bioactivity of MM and explain the popularity of this plant in the folk medicine as a remedy for different illnesses.
    Matched MeSH terms: Cells, Cultured
  18. Fulltext Effect of Catha edulis (khat) on pancreatic functions in streptozotocin-induced diabetes in male Sprague-Dawley rats
    Alsalahi A, Alshawsh MA, Chik Z, Mohamed Z
    Exp Anim, 2018 Nov 01;67(4):517-526.
    PMID: 29973470 DOI: 10.1538/expanim.18-0057
    People consume Catha edulis (khat) for its euphoric effect, and type 1 diabetics have claimed that khat could reduce elevated levels of blood sugar. However, khat has been suggested to provoke diabetes mellitus through destruction of pancreatic β-cells. This study investigated the effect of an ethanolic khat extract on pancreatic functions in type 1 diabetes (T1DM)-induced male Sprague-Dawley rats and to assess its in vitro cytotoxicity in rat pancreatic β-cells (RIN-14B). T1DM was induced in a total of 20 rats with a single intraperitoneal injection of 75 mg/kg of streptozotocin. The rats were distributed into four groups (n=5): the diabetic control, 8 IU insulin-treated, 200 mg/kg khat-treated, and 400 mg/kg khat-treated groups. Another 5 rats were included as a nondiabetic control. Body weight, fasting blood sugar, and caloric intake were recorded weekly. Four weeks after treatment, the rats were sacrificed, and blood was collected for insulin, lipid profile, total protein, amylase, and lipase analysis, while pancreases were harvested for histopathology. In vitro, khat exerted moderate cytotoxicity against RIN-14B cells after 24 and 48 h but demonstrated greater inhibition against RIN-14B cells after 72 h. Neither 200 mg/kg nor 400 mg/kg of khat produced any significant reduction in blood sugar; however, 200 mg/kg khat extract provoked more destruction of pancreatic β-cells as compared with the diabetic control. Ultimately, neither 200 mg/kg nor 400 mg/kg of khat extract could produce a hypoglycemic effect in T1DM-induced rats. However, 200 mg/kg of khat caused greater destruction of pancreatic β-cells, implying that khat may cause a direct cytotoxic effect on pancreatic β-cells in vitro.
    Matched MeSH terms: Tumor Cells, Cultured
  19. Bone regeneration performance of surface-treated porous titanium
    Amin Yavari S, van der Stok J, Chai YC, Wauthle R, Tahmasebi Birgani Z, Habibovic P, et al.
    Biomaterials, 2014 Aug;35(24):6172-81.
    PMID: 24811260 DOI: 10.1016/j.biomaterials.2014.04.054
    The large surface area of highly porous titanium structures produced by additive manufacturing can be modified using biofunctionalizing surface treatments to improve the bone regeneration performance of these otherwise bioinert biomaterials. In this longitudinal study, we applied and compared three types of biofunctionalizing surface treatments, namely acid-alkali (AcAl), alkali-acid-heat treatment (AlAcH), and anodizing-heat treatment (AnH). The effects of treatments on apatite forming ability, cell attachment, cell proliferation, osteogenic gene expression, bone regeneration, biomechanical stability, and bone-biomaterial contact were evaluated using apatite forming ability test, cell culture assays, and animal experiments. It was found that AcAl and AnH work through completely different routes. While AcAl improved the apatite forming ability of as-manufactured (AsM) specimens, it did not have any positive effect on cell attachment, cell proliferation, and osteogenic gene expression. In contrast, AnH did not improve the apatite forming ability of AsM specimens but showed significantly better cell attachment, cell proliferation, and expression of osteogenic markers. The performance of AlAcH in terms of apatite forming ability and cell response was in between both extremes of AnH and AsM. AcAl resulted in significantly larger volumes of newly formed bone within the pores of the scaffold as compared to AnH. Interestingly, larger volumes of regenerated bone did not translate into improved biomechanical stability as AnH exhibited significantly better biomechanical stability as compared to AcAl suggesting that the beneficial effects of cell-nanotopography modulations somehow surpassed the benefits of improved apatite forming ability. In conclusion, the applied surface treatments have considerable effects on apatite forming ability, cell attachment, cell proliferation, and bone ingrowth of the studied biomaterials. The relationship between these properties and the bone-implant biomechanics is, however, not trivial.
    Matched MeSH terms: Cells, Cultured
  20. Effects of anodizing parameters and heat treatment on nanotopographical features, bioactivity, and cell culture response of additively manufactured porous titanium
    Amin Yavari S, Chai YC, Böttger AJ, Wauthle R, Schrooten J, Weinans H, et al.
    Mater Sci Eng C Mater Biol Appl, 2015 Jun;51:132-8.
    PMID: 25842117 DOI: 10.1016/j.msec.2015.02.050
    Anodizing could be used for bio-functionalization of the surfaces of titanium alloys. In this study, we use anodizing for creating nanotubes on the surface of porous titanium alloy bone substitutes manufactured using selective laser melting. Different sets of anodizing parameters (voltage: 10 or 20V anodizing time: 30min to 3h) are used for anodizing porous titanium structures that were later heat treated at 500°C. The nanotopographical features are examined using electron microscopy while the bioactivity of anodized surfaces is measured using immersion tests in the simulated body fluid (SBF). Moreover, the effects of anodizing and heat treatment on the performance of one representative anodized porous titanium structures are evaluated using in vitro cell culture assays using human periosteum-derived cells (hPDCs). It has been shown that while anodizing with different anodizing parameters results in very different nanotopographical features, i.e. nanotubes in the range of 20 to 55nm, anodized surfaces have limited apatite-forming ability regardless of the applied anodizing parameters. The results of in vitro cell culture show that both anodizing, and thus generation of regular nanotopographical feature, and heat treatment improve the cell culture response of porous titanium. In particular, cell proliferation measured using metabolic activity and DNA content was improved for anodized and heat treated as well as for anodized but not heat-treated specimens. Heat treatment additionally improved the cell attachment of porous titanium surfaces and upregulated expression of osteogenic markers. Anodized but not heat-treated specimens showed some limited signs of upregulated expression of osteogenic markers. In conclusion, while varying the anodizing parameters creates different nanotube structure, it does not improve apatite-forming ability of porous titanium. However, both anodizing and heat treatment at 500°C improve the cell culture response of porous titanium.
    Matched MeSH terms: Cells, Cultured
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