Displaying publications 1 - 20 of 34 in total

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  1. Thompson PA, Khatami M, Baglole CJ, Sun J, Harris SA, Moon EY, et al.
    Carcinogenesis, 2015 Jun;36 Suppl 1:S232-53.
    PMID: 26106141 DOI: 10.1093/carcin/bgv038
    An emerging area in environmental toxicology is the role that chemicals and chemical mixtures have on the cells of the human immune system. This is an important area of research that has been most widely pursued in relation to autoimmune diseases and allergy/asthma as opposed to cancer causation. This is despite the well-recognized role that innate and adaptive immunity play as essential factors in tumorigenesis. Here, we review the role that the innate immune cells of inflammatory responses play in tumorigenesis. Focus is placed on the molecules and pathways that have been mechanistically linked with tumor-associated inflammation. Within the context of chemically induced disturbances in immune function as co-factors in carcinogenesis, the evidence linking environmental toxicant exposures with perturbation in the balance between pro- and anti-inflammatory responses is reviewed. Reported effects of bisphenol A, atrazine, phthalates and other common toxicants on molecular and cellular targets involved in tumor-associated inflammation (e.g. cyclooxygenase/prostaglandin E2, nuclear factor kappa B, nitric oxide synthesis, cytokines and chemokines) are presented as example chemically mediated target molecule perturbations relevant to cancer. Commentary on areas of additional research including the need for innovation and integration of systems biology approaches to the study of environmental exposures and cancer causation are presented.
  2. Nahta R, Al-Mulla F, Al-Temaimi R, Amedei A, Andrade-Vieira R, Bay SN, et al.
    Carcinogenesis, 2015 Jun;36 Suppl 1:S2-18.
    PMID: 26106139 DOI: 10.1093/carcin/bgv028
    As part of the Halifax Project, this review brings attention to the potential effects of environmental chemicals on important molecular and cellular regulators of the cancer hallmark of evading growth suppression. Specifically, we review the mechanisms by which cancer cells escape the growth-inhibitory signals of p53, retinoblastoma protein, transforming growth factor-beta, gap junctions and contact inhibition. We discuss the effects of selected environmental chemicals on these mechanisms of growth inhibition and cross-reference the effects of these chemicals in other classical cancer hallmarks.
  3. Engström W, Darbre P, Eriksson S, Gulliver L, Hultman T, Karamouzis MV, et al.
    Carcinogenesis, 2015 Jun;36 Suppl 1:S38-60.
    PMID: 26106143 DOI: 10.1093/carcin/bgv030
    The aim of this work is to review current knowledge relating the established cancer hallmark, sustained cell proliferation to the existence of chemicals present as low dose mixtures in the environment. Normal cell proliferation is under tight control, i.e. cells respond to a signal to proliferate, and although most cells continue to proliferate into adult life, the multiplication ceases once the stimulatory signal disappears or if the cells are exposed to growth inhibitory signals. Under such circumstances, normal cells remain quiescent until they are stimulated to resume further proliferation. In contrast, tumour cells are unable to halt proliferation, either when subjected to growth inhibitory signals or in the absence of growth stimulatory signals. Environmental chemicals with carcinogenic potential may cause sustained cell proliferation by interfering with some cell proliferation control mechanisms committing cells to an indefinite proliferative span.
  4. Langie SA, Koppen G, Desaulniers D, Al-Mulla F, Al-Temaimi R, Amedei A, et al.
    Carcinogenesis, 2015 Jun;36 Suppl 1:S61-88.
    PMID: 26106144 DOI: 10.1093/carcin/bgv031
    Genome instability is a prerequisite for the development of cancer. It occurs when genome maintenance systems fail to safeguard the genome's integrity, whether as a consequence of inherited defects or induced via exposure to environmental agents (chemicals, biological agents and radiation). Thus, genome instability can be defined as an enhanced tendency for the genome to acquire mutations; ranging from changes to the nucleotide sequence to chromosomal gain, rearrangements or loss. This review raises the hypothesis that in addition to known human carcinogens, exposure to low dose of other chemicals present in our modern society could contribute to carcinogenesis by indirectly affecting genome stability. The selected chemicals with their mechanisms of action proposed to indirectly contribute to genome instability are: heavy metals (DNA repair, epigenetic modification, DNA damage signaling, telomere length), acrylamide (DNA repair, chromosome segregation), bisphenol A (epigenetic modification, DNA damage signaling, mitochondrial function, chromosome segregation), benomyl (chromosome segregation), quinones (epigenetic modification) and nano-sized particles (epigenetic pathways, mitochondrial function, chromosome segregation, telomere length). The purpose of this review is to describe the crucial aspects of genome instability, to outline the ways in which environmental chemicals can affect this cancer hallmark and to identify candidate chemicals for further study. The overall aim is to make scientists aware of the increasing need to unravel the underlying mechanisms via which chemicals at low doses can induce genome instability and thus promote carcinogenesis.
  5. Ochieng J, Nangami GN, Ogunkua O, Miousse IR, Koturbash I, Odero-Marah V, et al.
    Carcinogenesis, 2015 Jun;36 Suppl 1:S128-59.
    PMID: 26106135 DOI: 10.1093/carcin/bgv034
    The purpose of this review is to stimulate new ideas regarding low-dose environmental mixtures and carcinogens and their potential to promote invasion and metastasis. Whereas a number of chapters in this review are devoted to the role of low-dose environmental mixtures and carcinogens in the promotion of invasion and metastasis in specific tumors such as breast and prostate, the overarching theme is the role of low-dose carcinogens in the progression of cancer stem cells. It is becoming clearer that cancer stem cells in a tumor are the ones that assume invasive properties and colonize distant organs. Therefore, low-dose contaminants that trigger epithelial-mesenchymal transition, for example, in these cells are of particular interest in this review. This we hope will lead to the collaboration between scientists who have dedicated their professional life to the study of carcinogens and those whose interests are exclusively in the arena of tissue invasion and metastasis.
  6. Casey SC, Vaccari M, Al-Mulla F, Al-Temaimi R, Amedei A, Barcellos-Hoff MH, et al.
    Carcinogenesis, 2015 Jun;36 Suppl 1:S160-83.
    PMID: 26106136 DOI: 10.1093/carcin/bgv035
    Potentially carcinogenic compounds may cause cancer through direct DNA damage or through indirect cellular or physiological effects. To study possible carcinogens, the fields of endocrinology, genetics, epigenetics, medicine, environmental health, toxicology, pharmacology and oncology must be considered. Disruptive chemicals may also contribute to multiple stages of tumor development through effects on the tumor microenvironment. In turn, the tumor microenvironment consists of a complex interaction among blood vessels that feed the tumor, the extracellular matrix that provides structural and biochemical support, signaling molecules that send messages and soluble factors such as cytokines. The tumor microenvironment also consists of many host cellular effectors including multipotent stromal cells/mesenchymal stem cells, fibroblasts, endothelial cell precursors, antigen-presenting cells, lymphocytes and innate immune cells. Carcinogens can influence the tumor microenvironment through effects on epithelial cells, the most common origin of cancer, as well as on stromal cells, extracellular matrix components and immune cells. Here, we review how environmental exposures can perturb the tumor microenvironment. We suggest a role for disrupting chemicals such as nickel chloride, Bisphenol A, butyltins, methylmercury and paraquat as well as more traditional carcinogens, such as radiation, and pharmaceuticals, such as diabetes medications, in the disruption of the tumor microenvironment. Further studies interrogating the role of chemicals and their mixtures in dose-dependent effects on the tumor microenvironment could have important general mechanistic implications for the etiology and prevention of tumorigenesis.
  7. Chan PF, Ang KP, Hamid RA
    Biometals, 2021 04;34(2):365-391.
    PMID: 33555494 DOI: 10.1007/s10534-021-00286-0
    Interest in bismuth(III) dithiocarbamate complexes as potential drug candidates is increasing due to their low toxicity compared to other group 15 elements (pnictogen) of the periodic table. Bismuth dithiocarbamate compounds have been reported to induce greater cytotoxicity in various human carcinoma cancer cell lines. Using various in vitro cancer-related assays, we investigated the antiproliferative activity of bismuth diethyldithiocarbamate, denoted as 1, against the MCF-7 human breast adenocarcinoma cell line and the effect on genes that may be involved in antiproliferation, apoptosis, DNA fragmentation, invasion and polyubiquitination functions. In general, 1 exhibited high cytotoxicity in MCF-7 cells, with an IC50 of 1.26 ± 0.02 µM, by inducing the intrinsic apoptotic pathway, as ascertained by measurements of intracellular reactive oxygen species (ROS), caspase activity, the amount of cytochrome c released and the extent of DNA fragmentation and by staining assays that reveal apoptotic cells. In addition, 1 significantly attenuated cell invasion and modulated several cancer-related genes, including PLK2, FIGF, FLT4, PARP4, and HDAC11, as determined via gene expression analysis. The NF-κB signaling pathway was inhibited by 1 upon the activation of Lys48- and Lys63-linked polyubiquitination, thus leading to its degradation via the proteasome. Overall, 1 has the potential to act as an antiproliferative agent and a proteasome inhibitor in estrogen-positive breast cancer.
  8. Ang KP, Chan PF, Hamid RA
    Biometals, 2021 02;34(1):141-160.
    PMID: 33196940 DOI: 10.1007/s10534-020-00269-7
    Based on the recent studies depicting the potential of heterometallic gold complexes as potent antiproliferative agents, herein we first reported the preliminary mechanistic data on the in-vitro antiproliferative activity of tricyclohexylphosphanegold(I) n-mercaptobenzoate, Cy3PAu(n-MBA) where n = 2 (1), 3 (2) and 4 (3), and MBA = mercaptobenzoic acid, treated using MCF-7 breast cancer and A2780 ovarian cancer cells, respectively. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was used to assess the cytotoxicity of both cancer cells treated with 1-3, respectively. The IC50 of 1-3 were applied to the subsequent assays including cell invasion and thioredoxin reductase (TrxR) as well as ubiquitin activities specifically on Lys48 and Lys63-linked polyubiquitin chains via flowcytometric analysis. The mechanistic effect of 1-3 towards both cells were evaluated on human p53 signaling gene expressions via RT2 profiler Polymerase Chain Reductase (PCR) array. 1-3 were found to be highly cytotoxic towards both MCF-7 and A2780 cancer cell lines with the compounds were more sensitive towards the latter cells. 1-3 also suppressed TrxR and cell invasion activities by modulating p53 related genes related with proliferation, invasion and TrxR activities i.e. CCNB1, TP53, CDK4 etc. 1-3 also regulated Lys48 and Lys63-linked polyubiquitination by reactivation of p53, suggesting the ability of this gene in regulating inhibition of cytoskeletal reorganization via epithelial-mesenchymal transition (EMT), required for tumor progression. Taken together, the overall findings denoted that 1-3 exerted potent antiproliferative activity in MCF-7 and A2780 cells via activation of the p53 signaling pathway.
  9. Blin JA, Ali RM, Nurdin A, Hamid RA
    Inflammopharmacology, 2021 Jun;29(3):771-788.
    PMID: 34091811 DOI: 10.1007/s10787-021-00816-9
    Rheumatoid arthritis (RA) is a chronic joint disorder, of which, excessive angiogenesis is the well-established factor contributing to synovitis and joint destruction. Ardisia crispa (Primulaceae) is a medicinal herb with evidenced anti-angiogenic properties, attributed to 2-methoxy-6-undecyl-1,4-benzoquinone (BQ) found in its roots. However, it is still unclear how BQ is able to inhibit angiogenesis in RA. Hence, we investigated the anti-arthritic potential of quinone-rich fraction (QRF) separated from Ardisia crispa roots hexane extract (ACRH) by targeting angiogenesis on collagen-induced arthritis (CIA) in rats. The QRF was priorly identified by quantifying the BQ content in the fraction using GC-MS. Male Sprague-Dawley rats (n = 6) were initially immunised with type II collagen (150 µg) subcutaneously at the base of the tail on day 0. QRF (3, 10, and 30 mg/kg/day) and celecoxib (5 mg/kg/day) were orally administered for 13 consecutive days starting from day 14 post-induction, except for the vehicle and arthritic controls. QRF at all dosages moderately ameliorated the arthritic scores, ankle swelling, and hind paw oedema with no significant (p > 0.05) modulation on the bodyweights and organ weights (i.e., liver, kidney, and spleen). Treatment with QRF at 3, 10, and 30 mg/kg, significantly (p 
  10. Ang KP, Chan PF, Hamid RA
    J Biol Inorg Chem, 2021 10;26(7):833-853.
    PMID: 34476610 DOI: 10.1007/s00775-021-01892-6
    Tricyclohexylphosphanegold(I) n-mercaptobenzoate (n = 2, 3, 4) labelled as 1-3 were previously reported to significantly suppress thioredoxin reductase (TrxR) activities towards ovarian cancer cells, A2780, in vitro. Herein, we explored the role of 1-3 for their apoptosis inducing ability against A2780 cells. 1-3 exhibited IC50 values at 1.19 ± 0.03 µM, 2.28 ± 0.04 μM and 0.78 ± 0.01 μM, respectively, compared to cisplatin at 26.8 ± 0.15 µM. The compounds induced A2780 apoptosis via a caspase-dependent mitochondrion pathway as evidenced by ROS production, cytochrome c release, caspases-3/7, -8, -9 and -10 activation, APAF1 and BAX upregulation as well as BCL2A1 and BCL2 genes' downregulation. In addition, the death mode of 1-3 was also mediated via death receptor extrinsic pathway manifested by FAS, FASL, FADD, and TNFR1 genes' upregulation via Human Rt PCR analysis. In addition, 1-3 significantly caused A2780 arrest at S phase, which was associated with the upregulation of TP53, E2F1, RB1 and CDKN1A upregulation and downregulation of CDK1, CDK4, CDC25A and CDC25C genes. Based on these promising results, these phosphanegold(I) thiolate derivatives could act as feasible candidates for further advanced in vivo ovarian cancer studies to develop novel chemotherapeutic agents derived from metal-based agents.
  11. Pian AK, Foong CP, Hamid RA
    Life Sci, 2022 Dec 15;311(Pt B):121161.
    PMID: 36375571 DOI: 10.1016/j.lfs.2022.121161
    We have previously reported the inhibition of thioredoxin reductase (TrxR) and invasion by tricyclohexylphosphine gold (I) n-mercaptobenzoate (n = 2, 3, 4) labeled as 1-3 towards MCF-7 cells, in vitro. Nevertheless, the mode of death and its apoptotic pathway has yet to be revealed. The main aim of this study is to investigate the anti-neoplastic activity of this phosphanegold (I) thiolates against breast adenocarcinoma cells, MCF-7. Herein, we explored the role of gold(I) series, 1-3 for their apoptosis-inducing ability against MCF-7 cells. They were scrutinized for their antiproliferative activities which exhibited their IC50 values of 8.14 μM ± 0.10, 7.26 μM ± 0.33, and 9.03 μM ± 0.69, respectively, and indicated better cytotoxicities than that of cisplatin (positive control). Further, the mechanisms of their actions were studied by analyzing the status of ROS generation (by DCFH-DA), cytochrome c release (by ELISA), and activation of caspases 3/7, 8, 9, and 10, annexin V staining and cell cycle analysis by flow cytometry, respectively. It was observed that the compounds, 1-3 can promote ROS generation, cytochrome c release, and activation of caspases 3/7, caspase 8, caspase 9, and caspase 10 on MCF-7 cells. In addition, the compounds are shown to induce MCF-7 cell arrest at S-phase. Gene analysis via PCR array further clarified their effects by modulating the related genes upon the compounds' treatment. Further investigation on other breast cancer cells as well as in vivo studies on these compounds will further increase their potential as anti-breast cancer agents.
  12. Lim WJ, Chan PF, Hamid RA
    Saudi Pharm J, 2024 Jan;32(1):101891.
    PMID: 38111673 DOI: 10.1016/j.jsps.2023.101891
    The root hexane extract of Ardisia crispa (ACRH), which belongs to the Primulaceae family, has been reported to possess anti-inflammatory, chemopreventive, anti-arthritic, and antiangiogenic activities. In this study, we isolated a p-benzoquinone derivative, 2-methoxy-6-undecyl-1,4-benzoquinone (AC2), from ACRH and investigated its potential antiangiogenic activity in human umbilical vein endothelial cells (HUVECs) and zebrafish embryo models. Prior to this study, AC2 was characterized using 1H NMR spectroscopy and MS. AC2 significantly suppressed HUVEC proliferation in a time-independent manner, with an IC50 value of 1.35 ± 0.05, 1.15 ± 0.02, and 1.00 ± 0.01 µg/mL at 24, 48, and 72 h, respectively. AC2 also induced apoptosis in HUVECs and significantly suppressed their migration, invasion, and tube formation in a concentration-dependent manner. Additionally, AC2 significantly attenuated most of the analyzed protein markers, including pro-MMP-2, VEGF-C, VEGF-D, angiopoietin-2, endothelin-1, fibroblast growth factor (FGF)-1, FGF-2, follistatin, heparin-binding epidermal growth factor-like growth factor (HB-EGF), and hepatocyte growth factor (HGF) at all tested concentrations. Furthermore, AC2 significantly inhibited zebrafish embryo intersegmental vessels (ISVs), confirming its antiangiogenic role. In conclusion, AC2 exhibits a potential anti-angiogenic effect by suppressing several proangiogenic and growth factors. Further studies are needed to investigate their effects on other excessive angiogenic diseases.
  13. Chan PF, Ang KP, Hamid RA
    J Biol Inorg Chem, 2024 Feb 18.
    PMID: 38369679 DOI: 10.1007/s00775-023-02041-x
    We previously reported that the bismuth(III) dithiocarbamate derivative, bismuth diethyldithiocarbamate (1) exhibited greater cytotoxicity while inducing apoptosis via the intrinsic pathway in MCF-7 cells. We further evaluated the other bismuth(III) dithiocarbamate derivatives, Bi[S2CNR]3, with R = (CH2CH2OH)(iPr), (CH2)4, and (CH2CH2OH)(CH3), denoted as 2, 3, and 4, respectively, in the same MCF-7 cell line. 2-4 were found to exhibit IC50 values of 10.33 ± 0.06 µM, 1.07 ± 0.01 µM and 25.37 ± 0.12 µM, respectively, compared to that of cisplatin at 30.53 ± 0.23 µM. Apoptotic promotion via the mitochondrial-dependent pathway was due to the elevation of intracellular reactive oxygen species (ROS), promotion of caspases, release of cytochrome c, fragmentation of DNA, and results of staining assay observed in all compound-treated cells. 2-4 are also capable of suppressing MCF-7 cell invasion and modulate Lys-48 also Lys-63 linked polyubiquitination, leading to proteasomal degradation. Analysis of gene expression via qRT-PCR revealed their modulation, which supported all activities conducted upon treatment with 2-4. Altogether, bismuth dithiocarbamate derivatives, with bismuth(III) as the metal center bound to ligands, isopropyl ethanol, pyrrolidine, and methyl ethanol dithiocarbamate, are potential anti-breast cancer agents that induce apoptosis and suppress metastasis. Further studies using other breast cancer cell lines and in vivo studies are recommended to clarify the anticancer effects of these compounds.
  14. Khazaei S, Esa NM, Ramachandran V, Hamid RA, Pandurangan AK, Etemad A, et al.
    Front Pharmacol, 2017;8:5.
    PMID: 28197098 DOI: 10.3389/fphar.2017.00005
    Natural products are considered potent sources for novel drug discovery and development. The multiple therapeutic effects of natural compounds in traditional medicine motivate us to evaluate the cytotoxic activity of bulb of Allium atroviolaceum in MCF7 and MDA-MB-231, HeLa and HepG2 cell lines. The bulb methanol extract of A. atroviolaceum was found to be an active cell proliferation inhibitor at the time and dose dependent manner. Determination of DNA content by flow cytometry demonstrated S and G2/M phase arrest of MCF-7 cell, correlated to Cdk1 downregulation, S phase arrest in MDA-MB-231 which is p53 and Cdk1-dependent, sub-G0 cell cycle arrest in HeLa aligned with Cdk1 downregulation, G0/G1, S, G2/M phase arrest in HepG2 which is p53-dependent. Apoptosis as the mechanism of cell death was confirmed by morphology study, caspases activity assay, as well as apoptosis related gene expression, Bcl-2. Caspase-8, -9, and -3 activity with downregulation of Bcl-2 illustrated occurrence of both intrinsic and extrinsic pathways in MCF7, while caspase-3 and -8 activity revealed extrinsic pathway of apoptosis, although Bcl-2 downregulated. In HeLa cells, the activity of caspase-9 and -3 and downregulation of Bcl-2 shows intrinsic pathway or mitochondrial pathway, whereas HepG2 shows caspase independent apoptosis. Further, the combination of the extract with tamoxifen against MCF7 and MDA-MB-231 and combination with doxorubicin against HeLa and HeG2 demonstrated synergistic effect in most concentrations, suggests that the bulb of A. atroviolaceum may be useful for the treatment of cancer lonely or in combination with other drugs.
  15. Baharum Z, Akim AM, Taufiq-Yap YH, Hamid RA, Kasran R
    Molecules, 2014 Nov 10;19(11):18317-31.
    PMID: 25389662 DOI: 10.3390/molecules191118317
    The aims of this study were to determine the antioxidant and antiproliferative activity of the following Theobroma cacao plant part methanolic extracts: leaf, bark, husk, fermented and unfermented shell, pith, root, and cherelle. Antioxidant activity was determined using 2,2-diphenyl-2-picrylhydrazyl (DPPH), thiobarbituric acid-reactive substances (TBARS), and Folin-Ciocalteu assays; the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium (MTT) assay was used to determine antiproliferative activity. The root extract had the highest antioxidant activity; its median effective dose (EC50) was 358.3±7.0 µg/mL and total phenolic content was 22.0±1.1 g GAE/100 g extract as compared to the other methanolic plant part extracts. Only the cherelle extract demonstrated 10.4%±1.1% inhibition activity in the lipid peroxidation assay. The MTT assay revealed that the leaf extract had the highest antiproliferative activity against MCF-7 cells [median inhibitory concentration (IC50)=41.4±3.3 µg/mL]. Given the overall high IC50 for the normal liver cell line WRL-68, this study indicates that T. cacao methanolic extracts have a cytotoxic effect in cancer cells, but not in normal cells. Planned future investigations will involve the purification, identification, determination of the mechanisms of action, and molecular assay of T. cacao plant extracts.
  16. Yeong LT, Hamid RA, Yazan LS, Khaza'ai H
    Asian Pac J Cancer Prev, 2013;14(4):2301-5.
    PMID: 23725131
    Ardisia crispa (Family: Myrsinaceae) is an evergreen, fruiting shrub that has been traditionally used as folklore medicine. Despite a scarcity of research publications, we have succeeded in showing suppressive effects on murine skin papillomagenesis. In extension, the present research was aimed at determining the effect of a quinone-rich fraction (QRF) isolated from the same root hexane extract on both initiation and promotion stages of carcinogenesis, at the selected dose of 30 mg/kg. Mice (groups I-IV) were initiated with a single dose of 7,12-dimethylbenz(α)anthracene (DMBA, 100 μg/100 μl) followed by repeated promotion of croton oil (1%) twice weekly for 20 weeks. In addition, group I (anti-initiation) received QRF 7 days before and after DMBA; group II (anti-promotion) received QRF 30 minutes before each croton oil application; group III (anti-initiation/ promotion) was treated with QRF as a combination of group I and II. A further two groups served as vehicle control (group V) and treated control (group VI). As carcinogen control, group IV showed the highest tumor volume (8.79±5.44) and tumor burden (3.60±1.17). Comparatively, group III revealed only 20% of tumor incidence, tumor burden (3.00±1.00) and tumor volume (2.40±1.12), which were significantly different from group IV. Group II also showed significant reduction of tumor volume (3.11), tumor burden (3.00) and tumor incidence (11.11%), along with prominent increase of latency period of tumor formation (week 12). Group I, nonetheless, demonstrated marked increment of tumor incidence by 40% with prompted latency period of tumor formation (week 7). No tumor formation was observed in groups V and VI. This study provided clear evidence of inhibitory effects of QRF during promotion period which was in agreement with our previous findings. The mechanism(s) underlying such effects have yet to be elucidated.
  17. Blin JA, Hamid RA, Khaza'ai H
    BMC Complement Med Ther, 2021 Jun 25;21(1):176.
    PMID: 34172047 DOI: 10.1186/s12906-021-03341-y
    BACKGROUND: Ardisia crispa (Thunb.) A.DC (Primulaceae), is a medicinal herb traditionally used by Asian people as remedies to cure inflammatory related diseases, including rheumatism. The plant roots possess various pharmacological activities including antipyretic, anti-inflammation and antitumor. Previous phytochemical studies of the plant roots have identified long chain alkyl-1,4-benzoquinones as major constituents, together with other phytochemicals. Hexane fraction of the plant roots (ACRH), was previously reported with anti-angiogenic and anti-arthritic properties, while its effect on their anti-arthritic in vitro, is yet unrevealed. Considering the significance of angiogenesis inhibition in developing new anti-arthritic agent, thus we investigated the anti-arthritic potential of Ardisia crispa roots by suppressing angiogenesis, in vitro.

    METHODS: Ardisia crispa roots hexane extract (ACRH) was prepared from the plant roots using absolute n-hexane. ACRH was fractionated into quinone-rich fraction (QRF) and further isolated to yield benzoquinonoid compound (BQ), respectively. In vitro experiments using VEGF-induced human umbilical vein endothelial cells (HUVECs) and IL-1β-induced human fibroblast-like synoviocytes for rheumatoid arthritis (HFLS-RA) were performed to evaluate the effects of these samples on VEGF-induced HUVECs proliferation and tube formation, and towards IL-1β-induced HFLS-RA proliferation, invasion, and apoptosis, respectively. Therapeutic concentrations (0.05, 0.5, and 5 μg/mL) tested in this study were predetermined based on the IC50 values obtained from the MTT assay.

    RESULTS: ACRH, QRF, and BQ exerted concentration-independent antiproliferative effects on VEGF-induced HUVECs and IL-1β-induced HFLS-RA, with IC50 values at 1.09 ± 0.18, 3.85 ± 0.26, and 1.34 ± 0.16 μg/mL in HUVECs; and 3.60 ± 1.38, 4.47 ± 0.34, and 1.09 ± 0.09 μg/mL in HFLS-RA, respectively. Anti-angiogenic properties of these samples were verified via significant inhibition on VEGF-induced HUVECs tube formation, in a concentration-independent manner. The invasiveness of IL-1β-induced HFLS-RA was also significantly inhibited in a concentration-independent manner by all samples. ACRH and BQ, but not QRF, significantly enhanced the apoptosis of IL-1β-induced HFLS-RA elicited at their highest concentration (5 μg/mL) (P RA's cellular functions in vitro, possibly mediated via their anti-angiogenic effects.

  18. Guo HF, Ali RM, Hamid RA, Zaini AA, Khaza'ai H
    Int J Burns Trauma, 2017;7(6):107-114.
    PMID: 29119063
    Burn injuries are one of the most devastating injuries in the world. A uniform burn wound is essential for burn research. The objective of this study was to describe a new model for inducing deep partial-thickness burns in rats. Burn wounds were performed on the dorsal part of Sprague-Dawley rats using a constructed heating device in our laboratory. Digital images of each animal were captured every day for macroscopic evaluation and for assessment of the wound contraction rate. Six animals were sacrificed on days 1, 3, 7, 11, 14, and 21 after onset of burn and their skin tissues were harvested for histological analysis. Uniform deep partial-thickness burns could be achieved in Sprague-Dawley rats under the condition of a contact temperature of 70°C, with the weight of heating devices of 300 g, and a duration of 10 s. Macroscopic evaluation recorded the general appearance of the deep partial-thickness burns. Evaluation of the wound contraction rate showed that the deep partial-thickness wound area was reduced by 90.39% of the original wound area by day 21 after burn. Microscopic evaluation by hematoxylin-eosin staining revealed the histological changes during the wound healing process. This is a standardized and reproducible model for inducing deep partial-thickness burns in Sprague-Dawley rats.
  19. Hu Z, Brooks SA, Dormoy V, Hsu CW, Hsu HY, Lin LT, et al.
    Carcinogenesis, 2015 Jun;36 Suppl 1:S184-202.
    PMID: 26106137 DOI: 10.1093/carcin/bgv036
    One of the important 'hallmarks' of cancer is angiogenesis, which is the process of formation of new blood vessels that are necessary for tumor expansion, invasion and metastasis. Under normal physiological conditions, angiogenesis is well balanced and controlled by endogenous proangiogenic factors and antiangiogenic factors. However, factors produced by cancer cells, cancer stem cells and other cell types in the tumor stroma can disrupt the balance so that the tumor microenvironment favors tumor angiogenesis. These factors include vascular endothelial growth factor, endothelial tissue factor and other membrane bound receptors that mediate multiple intracellular signaling pathways that contribute to tumor angiogenesis. Though environmental exposures to certain chemicals have been found to initiate and promote tumor development, the role of these exposures (particularly to low doses of multiple substances), is largely unknown in relation to tumor angiogenesis. This review summarizes the evidence of the role of environmental chemical bioactivity and exposure in tumor angiogenesis and carcinogenesis. We identify a number of ubiquitous (prototypical) chemicals with disruptive potential that may warrant further investigation given their selectivity for high-throughput screening assay targets associated with proangiogenic pathways. We also consider the cross-hallmark relationships of a number of important angiogenic pathway targets with other cancer hallmarks and we make recommendations for future research. Understanding of the role of low-dose exposure of chemicals with disruptive potential could help us refine our approach to cancer risk assessment, and may ultimately aid in preventing cancer by reducing or eliminating exposures to synergistic mixtures of chemicals with carcinogenic potential.
  20. Kravchenko J, Corsini E, Williams MA, Decker W, Manjili MH, Otsuki T, et al.
    Carcinogenesis, 2015 Jun;36 Suppl 1:S111-27.
    PMID: 26002081 DOI: 10.1093/carcin/bgv033
    An increasing number of studies suggest an important role of host immunity as a barrier to tumor formation and progression. Complex mechanisms and multiple pathways are involved in evading innate and adaptive immune responses, with a broad spectrum of chemicals displaying the potential to adversely influence immunosurveillance. The evaluation of the cumulative effects of low-dose exposures from the occupational and natural environment, especially if multiple chemicals target the same gene(s) or pathway(s), is a challenge. We reviewed common environmental chemicals and discussed their potential effects on immunosurveillance. Our overarching objective was to review related signaling pathways influencing immune surveillance such as the pathways involving PI3K/Akt, chemokines, TGF-β, FAK, IGF-1, HIF-1α, IL-6, IL-1α, CTLA-4 and PD-1/PDL-1 could individually or collectively impact immunosurveillance. A number of chemicals that are common in the anthropogenic environment such as fungicides (maneb, fluoxastrobin and pyroclostrobin), herbicides (atrazine), insecticides (pyridaben and azamethiphos), the components of personal care products (triclosan and bisphenol A) and diethylhexylphthalate with pathways critical to tumor immunosurveillance. At this time, these chemicals are not recognized as human carcinogens; however, it is known that they these chemicalscan simultaneously persist in the environment and appear to have some potential interfere with the host immune response, therefore potentially contributing to promotion interacting with of immune evasion mechanisms, and promoting subsequent tumor growth and progression.
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