Displaying publications 1 - 20 of 168 in total

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  1. Subramani T, Rathnavelu V, Alitheen NB
    Mediators Inflamm, 2013;2013:639468.
    PMID: 23690667 DOI: 10.1155/2013/639468
    Gingival overgrowth is a side effect of certain medications. The most fibrotic drug-induced lesions develop in response to therapy with phenytoin, the least fibrotic lesions are caused by cyclosporin A, and the intermediate fibrosis occurs in nifedipine-induced gingival overgrowth. Fibrosis is one of the largest groups of diseases for which there is no therapy but is believed to occur because of a persistent tissue repair program. During connective tissue repair, activated gingival fibroblasts synthesize and remodel newly created extracellular matrix. Proteins such as transforming growth factor (TGF), endothelin-1 (ET-1), angiotensin II (Ang II), connective tissue growth factor (CCN2/CTGF), insulin-like growth factor (IGF), and platelet-derived growth factor (PDGF) appear to act in a network that contributes to the development of gingival fibrosis. Since inflammation is the prerequisite for gingival overgrowth, mast cells and its protease enzymes also play a vital role in the pathogenesis of gingival fibrosis. Drugs targeting these proteins are currently under consideration as antifibrotic treatments. This review summarizes recent observations concerning the contribution of TGF-β, CTGF, IGF, PDGF, ET-1, Ang II, and mast cell chymase and tryptase enzymes to fibroblast activation in gingival fibrosis and the potential utility of agents blocking these proteins in affecting the outcome of drug-induced gingival overgrowth.
  2. Alitheen NB, McClure S, McCullagh P
    Immunol Cell Biol, 2010 01 19;88(4):445-50.
    PMID: 20084079 DOI: 10.1038/icb.2009.119
    Interspecies variations in the processes of B-cell development and repertoire generation contrast with the greater consistency of T-cell development. B-cell development in mice and humans, with postnatal B-cell generation of new repertoire in the bone marrow throughout life, is regarded as the 'standard' pattern. In contrast, accounts of B cells in birds, sheep, cattle, rabbits and pigs (the 'other' species) describe cessation of gene diversification in the perinatal period, with the gut-associated lymphoid tissue (GALT) functioning as the primary lymphoid organ thereafter. It has become customary to regard the developmental pathways of T and B cells within any individual species as being as dissimilar as the functions of the two mature cell types. Reinterpretation of B-cell development patterns in different species is overdue in response to two types of reports. The first of these describe T-B 'crossover', specifically the intrathymic production of B cells and the extrathymic production of T cells. The second attests to the extent of sharing of B-cell developmental features across the two groups of species. We propose that, as is a feature of other haematopoietic cells, a menu of alternative B- and T-cell pathways has been retained and shared across species. A single pathway usually predominates in any species, masking alternatives. The observed predominance of any pathway is determined by factors such as placental permeability, extent of maturation of the immune system by birth and the feasibility of direct experimental intervention in development.
  3. Yap WB, Tey BT, Alitheen NB, Tan WS
    J Biosci Bioeng, 2012 Jan;113(1):26-9.
    PMID: 22024533 DOI: 10.1016/j.jbiosc.2011.09.007
    The C-terminal domain of Nipah virus (NiV) nucleocapsid protein (NP₄₀₁₋₅₃₂) was inserted at the N-terminus and the immunodominant loop of hepatitis B core antigen (HBc). The stability of NP₄₀₁₋₅₃₂ increased tremendously when displayed on the HBc particles. These particles reacted specifically with the swine anti-NiV and the human anti-HBc antisera.
  4. Yap WB, Tey BT, Alitheen NB, Tan WS
    J Chromatogr A, 2010 May 21;1217(21):3473-80.
    PMID: 20388569 DOI: 10.1016/j.chroma.2010.03.012
    Hepatitis B core antigen (HBcAg) is used as a diagnostic reagent for the detection of hepatitis B virus infection. In this study, immobilized metal affinity-expanded bed adsorption chromatography (IMA-EBAC) was employed to purify N-terminally His-tagged HBcAg from unclarified bacterial homogenate. Streamline Chelating was used as the adsorbent and the batch adsorption experiment showed that the optimal binding pH of His-tagged HBcAg was 8.0 with a binding capacity of 1.8 mg per ml of adsorbent. The optimal elution condition for the elution of His-tagged HBcAg from the adsorbent was at pH 7 in the presence of 500 mM imidazole and 1.5 M NaCl. The IMA-EBAC has successfully recovered 56% of His-tagged HBcAg from the unclarified E. coli homogenate with a purification factor of 3.64. Enzyme-linked immunosorbent assay (ELISA) showed that the antigenicity of the recovered His-tagged HBcAg was not affected throughout the IMA-EBAC purification process and electron microscopy revealed that the protein assembled into virus-like particles (VLP).
  5. Subramani T, Rathnavelu V, Alitheen NB, Padmanabhan P
    Int J Mol Med, 2015 May;35(5):1151-8.
    PMID: 25812632 DOI: 10.3892/ijmm.2015.2144
    Gingival overgrowth is an undesirable outcome of systemic medication and is evidenced by the accretion of collagenous components in gingival connective tissues along with diverse degrees of inflammation. Phenytoin therapy has been found to induce the most fibrotic lesions in gingiva, cyclosporine caused the least fibrotic lesions, and nifedipine induced intermediate fibrosis in drug‑induced gingival overgrowth. In drug‑induced gingival overgrowth, efficient oral hygiene is compromised and has negative consequences for the systemic health of the patients. Toll‑like receptors (TLRs) are involved in the effective recognition of microbial agents and play a vital role in innate immunity and inflammatory signaling responses. TLRs stimulate fibrosis and tissue repairs in several settings, although with evident differences between organs. In particular, TLRs exert a distinct effect on fibrosis in organs with greater exposure to TLR ligands, such as the gingiva. Cumulative evidence from diverse sources suggested that TLRs can affect gingival overgrowth in several ways. Numerous studies have demonstrated the expression of TLRs in gingival tissues and suggested its potential role in gingival inflammation, cell proliferation and synthesis of the extracellular matrix which is crucial to the development of gingival overgrowth. In the present review, we assessed the role of TLRs on individual cell populations in gingival tissues that contribute to the progression of gingival inflammation, and the involvement of TLRs in the development of gingival overgrowth. These observations suggest that TLRs provide new insight into the connection among infection, inflammation, drugs and gingival fibrosis, and are therefore efficient therapeutic target molecules. We hypothesize that TLRs are critical for the development and progression of gingival overgrowth, and thus blocking TLR expression may serve as a novel target for antifibrotic therapy.
  6. Rathnavelu V, Alitheen NB, Sohila S, Kanagesan S, Ramesh R
    Biomed Rep, 2016 Sep;5(3):283-288.
    PMID: 27602208
    Pineapple has been used as part of traditional folk medicine since ancient times and it continues to be present in various herbal preparations. Bromelain is a complex mixture of protease extracted from the fruit or stem of the pineapple plant. Although the complete molecular mechanism of action of bromelain has not been completely identified, bromelain gained universal acceptability as a phytotherapeutic agent due to its history of safe use and lack of side effects. Bromelain is widely administered for its well-recognized properties, such as its anti-inflammatory, antithrombotic and fibrinolytic affects, anticancer activity and immunomodulatory effects, in addition to being a wound healing and circulatory improvement agent. The current review describes the promising clinical applications and therapeutic properties of bromelain.
  7. Subramani T, Rathnavelu V, Yeap SK, Alitheen NB
    Mediators Inflamm, 2013;2013:275172.
    PMID: 23431239 DOI: 10.1155/2013/275172
    Mast cells (MCs) are multifunctional effector cells that were originally thought to be involved in allergic disorders. Now it is known that they contain an array of mediators with a multitude of effects on many other cells. MCs have become a recent concern in drug-induced gingival overgrowth (DIGO), an unwanted outcome of systemic medication. Most of the studies have confirmed the significant presence of inflammation as a prerequisite for the overgrowth to occur. The inflammatory changes within the gingival tissue appear to influence the interaction between the inducing drug and the fibroblast activity. The development of antibodies to MC-specific enzymes, tryptase and chymase, has facilitated the study of mast cells in DIGO. Many immunohistochemical studies involving MCs have been conducted; as a result, DIGO tissues are found to have increased the number of MCs in the gingiva, especially in the area of fibrosis. At the cellular level, gingival fibrogenesis is initiated by several mediators which induce the recruitment of a large number of inflammatory cells, including MCs. The purpose of this paper is to access the roles played by MCs in gingival overgrowth to hypothesize a relationship between these highly specialized cells in the pathogenesis of DIGO.
  8. Biabanikhankahdani R, Ho KL, Alitheen NB, Tan WS
    Nanomaterials (Basel), 2018 Apr 13;8(4).
    PMID: 29652827 DOI: 10.3390/nano8040236
    Modifications of virus-like nanoparticles (VLNPs) using chemical conjugation techniques have brought the field of virology closer to nanotechnology. The huge surface area to volume ratio of VLNPs permits multiple copies of a targeting ligand and drugs to be attached per nanoparticle. By exploring the chemistry of truncated hepatitis B core antigen (tHBcAg) VLNPs, doxorubicin (DOX) was coupled covalently to the external surface of these nanoparticles via carboxylate groups. About 1600 DOX molecules were conjugated on each tHBcAg VLNP. Then, folic acid (FA) was conjugated to lysine residues of tHBcAg VLNPs to target the nanoparticles to cancer cells over-expressing folic acid receptor (FR). The result demonstrated that the dual bioconjugated tHBcAg VLNPs increased the accumulation and uptake of DOX in the human cervical and colorectal cancer cell lines compared with free DOX, resulting in enhanced cytotoxicity of DOX towards these cells. The fabrication of these dual bioconjugated nanoparticles is simple, and drugs can be easily conjugated with a high coupling efficacy to the VLNPs without any limitation with respect to the cargo's size or charge, as compared with the pH-responsive system based on tHBcAg VLNPs. These dual bioconjugated nanoparticles also have the potential to be modified for other combinatorial drug deliveries.
  9. Mohamad NE, Abu N, Yeap SK, Alitheen NB
    Integr Cancer Ther, 2019 11 23;18:1534735419880258.
    PMID: 31752555 DOI: 10.1177/1534735419880258
    Background: This study aimed to evaluate the antitumor enhancing effect of bromelain consumption on 4T1-challenged mice treated with cisplatin. Methods: Mice challenged with 4T1 triple-negative breast cancer cells received water, bromelain, cisplatin, or bromelain + cisplatin treatment for 28 days. Tumor size was measured, and lung metastasis was evaluated by clonogenic assay. Expression of tumor inflammatory genes of the harvested tumor was quantified by polymerase chain reaction array and ELISA (enzyme-linked immunosorbent assay). Results: All treatments significantly reduced the size of tumor and lung metastasis, with combination treatment showing the best effect. Also, bromelain alone and combination treatment showed downregulation of the expression of tumor inflammatory genes (Gremlin [GREM1], interleukin 1β [IL-1β], interleukin-4 [IL-4], nuclear factor κB subunit 1 [NFκB1], and prostaglandin-endoperoxide synthase 2 [PTGS2]), tumor nitric oxide level, and serum IL-1β, and IL-4 levels. On the other hand, cisplatin treatment increased the expression of selected inflammatory markers. Conclusion: This study suggests that bromelain treatment could potentiate the antitumor effect of cisplatin on triple-negative breast cancer 4T1 cells through modulating the tumor environmental inflammation.
  10. Tan MP, Mohamed Alitheen NB, Tan WS, Yap WB
    Vaccines (Basel), 2022 Dec 01;10(12).
    PMID: 36560475 DOI: 10.3390/vaccines10122066
    The current influenza vaccines only confer protection against the circulating influenza subtypes, therefore universal vaccines are needed to prevent upcoming influenza outbreaks caused by emerging influenza subtypes. The extracellular domain of influenza A M2 protein (M2e) is highly conserved among different subtypes of influenza A viruses, and it is able to elicit protective immunity against the viruses. The influenza nucleoprotein (NP) was used to display the M2e in this study due to its promising T-cell response and adjuvanticity. The M2e gene was fused to the 5'-end of the NP gene and then cloned into pRSET B vector. The DNA sequencing analysis revealed six point mutations in the M2e-NP fusion gene, including one mutation in the M2e peptide and five mutations in the NP. The mutations were reverted using PCR site-directed mutagenesis. The recombinant plasmids (pRSET B-M2e-NP and pRSET B-mM2e-NP) were introduced into Escherichia coli (E. coli) BL21 (DE3) for protein expression. The mutated and non-mutated proteins were subsequently expressed and named mM2e-NP and M2e-NP, respectively. The expression of mM2e-NP and M2e-NP was not affected by the mutations. The binding of anti-M2e antibody to the purified native mM2e-NP and M2e-NP also remained active. However, when the anti-NP antibody was tested, the signal produced by mM2e-NP was very weak. The results implied that the amino acid changes in the NP had adversely impacted on the conformation of mM2e-NP and subsequently affected the antibody binding. In light of the remarkable antibody binding to the M2e-NP fusion protein, this study highly recommends the potential of M2e-NP as a universal influenza vaccine candidate.
  11. Ho WY, Liew SS, Yeap SK, Alitheen NB
    PMID: 34712346 DOI: 10.1155/2021/6355236
    Elephantopus scaber Linn, a traditional herb, exhibited anticancer properties, and it was cytotoxic against the monolayer estrogen receptor-positive breast cancer cell line, MCF-7, in the previous study. In order to determine the potential of E. scaber as a complementary medicine for breast cancer, this study aimed to evaluate the synergism between E. scaber and tamoxifen in cytotoxicity using MCF-7 in the form of 3-dimensional multicellular tumor spheroid (MCTS) cultures. MCTS represents a more reliable model for studying drug penetration as compared to monolayer cells due to its greater resemblance to solid tumor. Combination of E. scaber ethanol extract and tamoxifen, which were used in concentrations lower than their respective IC50 values, had successfully induced apoptosis on MCTS in this study. The combinatorial treatment showed >58% increase of lactate dehydrogenase release in cell media, cell cycle arrest at the S phase, and 1.3 fold increase in depolarization of mitochondrial membrane potential. The treated MCTS also experienced DNA fragmentation; this had been quantified by TUNEL-positive assay, which showed >64% increase in DNA damaged cells. Higher externalization of phospatidylserine and distorted and disintegrated spheroids stained by acridine orange/propidium iodide showed that the cell death was mainly due to apoptosis. Further exploration showed that the combinatorial treatment elevated caspases-8 and 9 activities involving both extrinsic and intrinsic pathways of apoptosis. The treatment also upregulated the expression of proapoptotic gene HSP 105 and downregulated the expression of prosurvival genes such as c-Jun, ICAM1, and VEGF. In conclusion, these results suggested that the coupling of E. scaber to low concentration of tamoxifen showed synergism in cytotoxicity and reducing drug resistance in estrogen receptor-positive breast cancer.
  12. Tan MP, Tan WS, Mohamed Alitheen NB, Yap WB
    Vaccines (Basel), 2021 Jul 04;9(7).
    PMID: 34358155 DOI: 10.3390/vaccines9070739
    Discovery of conserved antigens for universal influenza vaccines warrants solutions to a number of concerns pertinent to the currently licensed influenza vaccines, such as annual reformulation and mismatching with the circulating subtypes. The latter causes low vaccine efficacies, and hence leads to severe disease complications and high hospitalization rates among susceptible and immunocompromised individuals. A universal influenza vaccine ensures cross-protection against all influenza subtypes due to the presence of conserved epitopes that are found in the majority of, if not all, influenza types and subtypes, e.g., influenza matrix protein 2 ectodomain (M2e) and nucleoprotein (NP). Despite its relatively low immunogenicity, influenza M2e has been proven to induce humoral responses in human recipients. Influenza NP, on the other hand, promotes remarkable anti-influenza T-cell responses. Additionally, NP subunits are able to assemble into particles which can be further exploited as an adjuvant carrier for M2e peptide. Practically, the T-cell immunodominance of NP can be transferred to M2e when it is fused and expressed as a chimeric protein in heterologous hosts such as Escherichia coli without compromising the antigenicity. Given the ability of NP-M2e fusion protein in inducing cross-protective anti-influenza cell-mediated and humoral immunity, its potential as a universal influenza vaccine is therefore worth further exploration.
  13. Salehinejad P, Alitheen NB, Ali AM, Omar AR, Moshrefi M, Motamedi B, et al.
    Cytotechnology, 2015 May;67(3):449-60.
    PMID: 25344875 DOI: 10.1007/s10616-014-9703-6
    Many neural disorders are characterized by the loss of one or several types of neural cells. Human umbilical cord-derived mesenchymal cells (hUCMs) are capable of differentiating into neuron, astroglia-like and oligodendrocyte cell types. However, a reliable means of inducing the selective differentiation of hUCMs into neural cells in vitro has not yet been established. For induction of neural differentiation, hUCMs were seeded onto sterile glass slides and six various cocktails using a base medium (DMEM/LG) supplemented with 10 % FBS, retinoic acid (RA), dimethyl sulfoxide (DMSO), epidermal growth factor (EGF) and fibroblast growth factor (FGF) were used to compare their effect on neuronal, astrocyte and oligodandrocyte differentiation. The hUCMs were positive for mesenchymal markers, while they were negative for hematopoietic markers. Differentiation to adipogenic and osteogenic lineage was detected in these cells. Our data revealed that the cocktail consisting of DMEM/LG, FBS, RA, FGF, and EGF (DF/R/Fg/E group) induced hUCM cells to express the highest percentage of nestin, ß-tubulin III, neurofilament, and CNPase. The DF/Ds/Fg/E group led to the highest percentage of GFAP expression. While the expression levels of NF, GFAP, and CNPase were the lowest in the DF group. The least percentage of nestin and ß-tubulin III expression was observed in the DF/Ds group. We may conclude that FGF and EGF are important inducers for differentiation of hUCMs into neuron, astrocyte and oligodendrocyte. RA can induce hUCMs to differentiate into neuron and oligodendrocyte while for astrocyte differentiation DMSO had a pivotal role.
  14. Shokryazdan P, Sieo CC, Kalavathy R, Liang JB, Alitheen NB, Faseleh Jahromi M, et al.
    Biomed Res Int, 2014;2014:927268.
    PMID: 25105147 DOI: 10.1155/2014/927268
    The objective of this study was to isolate, identify, and characterize some lactic acid bacterial strains from human milk, infant feces, and fermented grapes and dates, as potential probiotics with antimicrobial activity against some human pathogenic strains. One hundred and forty bacterial strains were isolated and, after initial identification and a preliminary screening for acid and bile tolerance, nine of the best isolates were selected and further identified using 16 S rRNA gene sequences. The nine selected isolates were then characterized in vitro for their probiotic characteristics and their antimicrobial activities against some human pathogens. Results showed that all nine isolates belonged to the genus Lactobacillus. They were able to tolerate pH 3 for 3 h, 0.3% bile salts for 4 h, and 1.9 mg/mL pancreatic enzymes for 3 h. They exhibited good ability to attach to intestinal epithelial cells and were not resistant to the tested antibiotics. They also showed good antimicrobial activities against the tested pathogenic strains of humans, and most of them exhibited stronger antimicrobial activity than the reference strain L. casei Shirota. Thus, the nine Lactobacillus strains could be considered as potential antimicrobial probiotic strains against human pathogens and should be further studied for their human health benefits.
  15. Goh SH, Alitheen NB, Yusoff FM, Yap SK, Loh SP
    Pharmacogn Mag, 2014 Jan;10(37):1-8.
    PMID: 24696543 DOI: 10.4103/0973-1296.126650
    Marine brown diatom Chaetoceros calcitrans and green microalga Nannochloropsis oculata are beneficial materials for various applications in the food, nutraceutical, pharmaceutical and cosmeceutical industries.
  16. Lee KH, Abas F, Mohamed Alitheen NB, Shaari K, Lajis NH, Israf DA, et al.
    Int J Rheum Dis, 2015 Jul;18(6):616-27.
    PMID: 24832356 DOI: 10.1111/1756-185X.12341
    Synovial fibroblast has emerged as a potential cellular target in progressive joint destruction in rheumatoid arthritis development. In this study, BDMC33 (2,6-bis[2,5-dimethoxybenzylidene]cyclohexanone), a curcumin analogue with enhanced anti-inflammatory activity has been synthesized and the potency of BDMC33 on molecular and cellular basis of synovial fibroblasts (SF) were evaluated in vitro.
  17. Zamzuri NA, Abd-Aziz S, Rahim RA, Phang LY, Alitheen NB, Maeda T
    J Appl Microbiol, 2014 Apr;116(4):903-10.
    PMID: 24314059 DOI: 10.1111/jam.12410
    To isolate a bacterial strain capable of biotransforming ferulic acid, a major component of lignin, into vanillin and vanillic acid by a rapid colorimetric screening method.
  18. Zuhaida AA, Ali AM, Tamilselvan S, Alitheen NB, Hamid M, Noor AM, et al.
    Genet. Mol. Res., 2013;12(4):5547-59.
    PMID: 24301925 DOI: 10.4238/2013.November.18.5
    A phage display library of single chain variable fragment (scFv) against MCF-7 breast cancer cells was constructed from C3A8 hybridoma cells. RNA from the C3A8 was isolated, cDNA was constructed, and variable heavy and light immunoglobulin chain gene region were amplified using PCR. The variable heavy and light chain gene regions were combined with flexible linker, linked to a pCANTAB 5E phagemid vector and electrophoresed into supE strain of Escherichia coli TG1 cells. Forty-eight clones demonstrated positive binding activity to MCF-7 breast cancer cell membrane fragments and the strongest of 48 clones was selected for analysis. The anti-MCF-7 library evaluated by SfiI and NotI digests demonstrated that anti-MCF-7 scFv antibodies possess individual patterns that should be able to recognize distinct human breast cancer cells. The C3A8 scFv, with an apparent molecular weight of 32 kDa, showed high homology (99%) with single chain antibody against rice stripe virus protein P20. In summary, the anti MCF-7 scFv antibody can be used for pretargeting breast cancer for clinical diagnosis of patients; it also has potential for therapeutic applications.
  19. Lee YY, Tang TK, Ab Karim NA, Alitheen NB, Lai OM
    Food Funct, 2014 Jan;5(1):57-64.
    PMID: 24247642 DOI: 10.1039/c3fo60358j
    Structured lipid medium- and long-chain triacylglycerols (MLCT) are claimed to be able to manage obesity. The present study investigated the body fat influence of enzymatically interesterifed palm-based medium- and long-chain triacylglycerols (P-MLCT) on diet-induced obesity (DIO) C57BL/6J mice compared with commercial MLCT oil (C-MLCT) and a control, which was the non enzymatically modified palm kernel and palm oil blend (PKO-PO blend). It also investigated the low fat and high fat effects of P-MLCT. DIO C57BL/6J mice were fed ad libitum with low fat (7%) and high fat (30%) experimental diets for 8 weeks before being sacrificed to obtain blood serum for analysis. From the results, there is a trend that P-MLCT fed mice were found to have the lowest body weight, body weight gain, total fat pad accumulation (perirenal, retroperitoneal, epididymal and mesenteric), total triglyceride levels and efficiency in controlling blood glucose level, compared with C-MLCT and the PKO-PO blend in both low fat and high fat diets. Nevertheless, the PKO-PO blend and P-MLCT caused significantly (P < 0.05) higher total cholesterol levels compared to C-MLCT. P-MLCT present in low fat and high fat dosage were shown to be able to suppress body fat accumulation. This effect is more prominent with the low fat dosage.
  20. Abu N, Ali NM, Ho WY, Yeap SK, Aziz MY, Alitheen NB
    Anticancer Agents Med Chem, 2014 Jun;14(5):750-5.
    PMID: 24164045
    The Noni fruit, or scientifically known as Morinda citrifolia can be found in various parts of the world, especially in the pacific region. It is a small evergreen bushy-like tree originated from the Rubiaceae family. The plant has been used by polynesians as a medicinal herb for more than 2000 years. A substantial amount of phytochemicals can be found in the roots of this plant. Among all, damnacanthal has been found to be the most interesting, versatile and potent compound. Damnacanthal or chemically known as,3- hydroxy-1-methoxyanthraquinone-2-caboxaldehyde (C16H10O5), appears as pale yellow crystals with a melting point of 210-211 °C. This compound is of particular interest due to its striking pharmacological properties. Damnacanthal was shown to inhibit the oncogene Ras, p56lck tyrosine kinase, NF-KB pathway and induce apoptosis in vitro. This review aims to discuss the biological properties of damnacanthal, specifically on its anti-cancer activity that has been reported.
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