Displaying publications 21 - 40 of 169 in total

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  1. Phuah NH, Azmi MN, Awang K, Nagoor NH
    Onco Targets Ther, 2017;10:1695-1705.
    PMID: 28356756 DOI: 10.2147/OTT.S117492
    BACKGROUND: Cervical cancer is the fourth most frequent malignancy affecting women worldwide, but drug resistance and toxicities remain a major challenge in chemotherapy. The use of natural compounds is promising because they are less toxic and able to target multiple signaling pathways. The 1'S-1'-acetoxychavicol acetate (ACA), a natural compound isolated from wild ginger Alpinia conchigera, induced cytotoxicity on various cancer cells including cervical cancer. MicroRNAs (miRNAs) are short noncoding RNAs that regulate numerous biological processes, such as apoptosis and chemosensitivity. Past studies reported that miR-629 is upregulated in many cancers, and its expression was altered in ACA-treated cervical cancer cells. However, the role of miR-629 in regulating sensitivity toward ACA or other anticancer agents has not been reported. Hence, this study aims to investigate the role of miR-629 in regulating response toward ACA on cervical cancer cells.

    METHODS: The miR-629 expression following transfection with miR-629 hairpin inhibitor and hairpin inhibitor negative control was measured using quantitative real-time polymerase chain reaction (RT-qPCR). The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to investigate sensitivity toward ACA. Apoptosis was detected using Annexin V/propidium iodide and Caspase 3/7 assays. The gene target for miR-629 was identified using miRNA target prediction programs, luciferase reporter assay and Western blots. Gene overexpression studies were performed to evaluate its role in regulating response toward ACA.

    RESULTS: Transfection with miR-629 hairpin inhibitor downregulated its expression in both cervical cancer cell lines. Suppression of miR-629 increased sensitivity toward ACA by reducing cell proliferation and inducing apoptosis. Luciferase reporter assay confirmed RSU1 as a direct target of miR-629. Overexpression of miR-629 decreased RSU1 protein expression, while inhibition of miR-629 increased RSU1 protein expression. Overexpression of RSU1 augmented antiproliferative and apoptosis-inducing effects of ACA.

    CONCLUSION: Our findings showed that combination of ACA with miR-629 and RSU1 may provide a potential strategy in treating cervical cancer.

  2. Kassim NK, Lim PC, Ismail A, Awang K
    Food Chem, 2019 Jan 30;272:185-191.
    PMID: 30309531 DOI: 10.1016/j.foodchem.2018.08.045
    The application of preparative thin layer chromatography-2,2-diphenyl-1-picrylhydrazyl (PTLC-DPPH) bioautography technique successfully isolated a lignan sesamin (1), two prenylated coumarins (2 and 3) and a marmesin glycosides (4) from Micromelum minutum methanol bark extract. Compounds 2 and 3 were identified as new compounds whereas 1 and 4 were first isolated from Micromelum genus. Structural identification of all compounds were done by detailed spectroscopic analyses and comparison with literature data. Antioxidant capacities of extract, active fraction and compounds were measured based on DPPH free radical savenging activity, oxygen radical absorbance capacity (ORAC) and β-carotene bleaching. The DPPH activity of methanol extract and its fraction present the IC50 values of 54.3 and 168.9 µg/mL meanwhile the β-carotene bleaching results were 55.19% and 5.75% respectively. The ORAC measurements of M. minutum extract, compounds 2 and 4 showed potent antioxidant activity with the values of 5123, 5539 and 4031 µmol TE/g respectively.
  3. Loo KY, Leong KH, Sivasothy Y, Ibrahim H, Awang K
    Chem Biodivers, 2019 Jun;16(6):e1900032.
    PMID: 30957403 DOI: 10.1002/cbdv.201900032
    The inhibition of carbohydrate-hydrolyzing enzymes in human digestive organs is crucial in controlling blood sugar levels, which is important in treating type 2 diabetes. In the current study, pahangensin A (1), a bis-labdanic diterpene characterized previously in the rhizomes of Alpinia pahangensis Ridl., was identified as an active dual inhibitor for α-amylase (IC50 =114.80 μm) and α-glucosidase (IC50 =153.87 μm). This is the first report on the dual α-amylase and α-glucosidase inhibitory activities of a bis-labdanic diterpene. The Lineweaver-Burk plots of compound 1 indicate that it is a mixed-type inhibitor with regard to both enzymes. Based on molecular docking studies, compound 1 docked in a non-active site of both enzymes. The dual inhibitory activity of compound 1 makes it a suitable natural alternative in the treatment of type 2 diabetes.
  4. Hematpoor A, Liew SY, Azirun MS, Awang K
    Sci Rep, 2017 10 03;7(1):12576.
    PMID: 28974710 DOI: 10.1038/s41598-017-12898-z
    Hexane, dichloromethane and methanol extracts of the roots of Piper sarmentosum Roxb. were screened for toxicity towards Sitophilus oryzae (L.), Rhyzopertha dominica (F.), and Plodia interpunctella (Hübner) and the hexane extract exhibited the highest mortality percentage. Bioassay-guided fractionation of the hexane extract resulted in the isolation of asaricin 1, isoasarone 2, and trans-asarone 3. Asaricin 1 and isoasarone 2 were the most toxic compounds to Sitophilus oryzae, Rhyzopertha dominica, and Plodia interpunctella. Sitophilus oryzae and Rhyzopertha dominica exposed to asaricin 1 and isoasarone 2 required the lowest median lethal time. Insecticidal activity of trans-asarone 3 showed consistent toxicity throughout the 60 days towards all three insects as compared to asaricin 1 and isoasarone 2. Asaricin 1 and isoasarone 2 at different doses significantly reduced oviposition and adult emergence of the three insects in treated rice. Trans-asarone 3 had lowest toxicity with highest LC and LT values in all tested insects relative to its mild oviposition inhibition and progeny activity. Moreover, asaricin 1 and isoasarone 2 significantly inhibited acetylcholinesterase in comparison with trans-asarone 3 and the control. Acetylcholinesterase inhibition of Rhyzopertha dominica and Plodia interpunctella by asaricin 1 and isoasarone 2 were lower than that of Sitophilus oryzae, which correlated with their higher resistance.
  5. Salim F, Ismail NH, Awang K, Ahmad R
    Molecules, 2011 Aug 04;16(8):6541-8.
    PMID: 21818057 DOI: 10.3390/molecules16086541
    Two new heteroyohimbine-type oxindole alkaloids, rauniticine-allo-oxindole B and rauniticinic-allo acid B, have been successfully isolated from the stems extract of Malaysian Uncaria longiflora var. pteropoda. The structures of the two new alkaloids were determined by spectroscopic analysis.
  6. Phuah NH, Azmi MN, Awang K, Nagoor NH
    Mol Cells, 2017 Apr;40(4):291-298.
    PMID: 28401751 DOI: 10.14348/molcells.2017.2285
    MicroRNAs (miRNAs) are short non-coding RNAs that regulate genes posttranscriptionally. Past studies have reported that miR-210 is up-regulated in many cancers including cervical cancer, and plays a pleiotropic role in carcinogenesis. However, its role in regulating response towards anti-cancer agents has not been fully elucidated. We have previously reported that the natural compound 1'S-1'-acetoxychavicol acetate (ACA) is able to induce cytotoxicity in various cancer cells including cervical cancer cells. Hence, this study aims to investigate the mechanistic role of miR-210 in regulating response towards ACA in cervical cancer cells. In the present study, we found that ACA down-regulated miR-210 expression in cervical cancer cells, and suppression of miR-210 expression enhanced sensitivity towards ACA by inhibiting cell proliferation and promoting apoptosis. Western blot analysis showed increased expression of mothers against decapentaplegic homolog 4 (SMAD4), which was predicted as a target of miR-210 by target prediction programs, following treatment with ACA. Luciferase reporter assay confirmed that miR-210 binds to sequences in 3'UTR of SMAD4. Furthermore, decreased in SMAD4 protein expression was observed when miR-210 was overexpressed. Conversely, SMAD4 protein expression increased when miR-210 expression was suppressed. Lastly, we demonstrated that overexpression of SMAD4 augmented the anti-proliferative and apoptosis-inducing effects of ACA. Taken together, our results demonstrated that down-regulation of miR-210 conferred sensitivity towards ACA in cervical cancer cells by targeting SMAD4. These findings suggest that combination of miRNAs and natural compounds could provide new strategies in treating cervical cancer.
  7. Awang K, Abdullah NH, Hadi AH, Fong YS
    J Biomed Biotechnol, 2012;2012:876458.
    PMID: 22536026 DOI: 10.1155/2012/876458
    The dichloromethane (DCM) extract of Andrographis paniculata Nees was tested for cardiovascular activity. The extract significantly reduced coronary perfusion pressure by up to 24.5 ± 3.0 mm Hg at a 3 mg dose and also reduced heart rate by up to 49.5 ± 11.4 beats/minute at this dose. Five labdane diterpenes, 14-deoxy-12-hydroxyandrographolide (1), 14-deoxy-11,12-didehydroandrographolide (2), 14-deoxyandrographolide (3), andrographolide (4), and neoandrographolide (5), were isolated from the aerial parts of this medicinal plant. Bioassay-guided studies using animal model showed that compounds, (2) and (3) were responsible for the coronary vasodilatation. This study also showed that andrographolide (4), the major labdane diterpene in this plant, has minimal effects on the heart.
  8. Rouhollahi E, Moghadamtousi SZ, Hajiaghaalipour F, Zahedifard M, Tayeby F, Awang K, et al.
    Drug Des Devel Ther, 2015;9:5805-13.
    PMID: 26604683 DOI: 10.2147/DDDT.S88196
    Curcuma purpurascens BI. is a member of Zingiberaceae family. The purpose of this study is to investigate the wound healing properties of hexane extract of C. purpurascens rhizome (HECP) against excisional wound healing in rats.
  9. Tiong SH, Looi CY, Arya A, Wong WF, Hazni H, Mustafa MR, et al.
    Fitoterapia, 2015 Apr;102:182-8.
    PMID: 25665941 DOI: 10.1016/j.fitote.2015.01.019
    Vindogentianine, a new indole alkaloid together with six known alkaloids, vindoline, vindolidine, vindolicine, vindolinine, perivine and serpentine were isolated from leaf extract (DA) of Catharanthus roseus (L.) G. Don. Their structures were elucidated by spectroscopic methods; NMR, MS, UV and IR. Vindogentianine is a dimer containing a vindoline moiety coupled to a gentianine moiety. After 24h incubation, vindogentianine exhibited no cytotoxic effect in C2C12 mouse myoblast and β-TC6 mouse pancreatic cells (IC50>50μg/mL). Real-time cell proliferation monitoring also indicated vindogentianine had little or no effect on C2C12 mouse myoblast cell growth at the highest dose tested (200μg/mL), without inducing cell death. Vindogentianine exhibited potential hypoglycemic activity in β-TC6 and C2C12 cells by inducing higher glucose uptake and significant in vitro PTP-1B inhibition. However, in vitro α-amylase and α-glucosidase inhibition assay showed low inhibition under treatment of vindogentianine. This suggests that hypoglycemic activity of vindogentianine may be due to the enhancement of glucose uptake and PTP-1B inhibition, implying its therapeutic potential against type 2 diabetes.
  10. Ibrahim H, Sivasothy Y, Syamsir DR, Nagoor NH, Jamil N, Awang K
    ScientificWorldJournal, 2014;2014:430831.
    PMID: 24987733 DOI: 10.1155/2014/430831
    The essential oils obtained by hydrodistillation of the unripe and ripe fruits of Alpinia mutica Roxb. and Alpinia latilabris Ridl. were analysed by capillary GC and GC-MS. The oils were principally monoterpenic in nature. The unripe and ripe fruit oils of A. mutica were characterized by camphor (21.0% and 15.8%), camphene (16.6% and 10.2%), β-pinene (8.6% and 13.5%), and trans,trans-farnesol (8.0% and 11.2%), respectively. The oils of the unripe and ripe fruits were moderately active against Staphylococcus aureus, Bacillus subtilis, Trichophyton mentagrophytes, and Trichophyton rubrum. 1,8-Cineole (34.2% and 35.9%) and β-pinene (20.2% and 19.0%) were the two most abundant components in the unripe and ripe fruit oils of A. latilabris. The oil of the unripe fruits elicits moderate activity against Staphylococcus aureus and Trichophyton mentagrophytes while Candida glabrata was moderately sensitive to the oil of the ripe fruits.
  11. Sim KS, Ibrahim H, Malek SN, Syamsir DR, Awang K
    Pharmacogn Mag, 2014 Jan;10(37):70-2.
    PMID: 24695515 DOI: 10.4103/0973-1296.126666
    Alpinia murdochii (Zingiberaceae) is a wild ginger species restricted to mountain areas of Peninsular Malaysia. Due to rapid development and deforestation activities, this species is becoming rare. This is the first report of the cytotoxic activity of A. murdochii.
  12. Beniddir MA, Le Borgne E, Iorga BI, Loaëc N, Lozach O, Meijer L, et al.
    J Nat Prod, 2014 May 23;77(5):1117-22.
    PMID: 24798019 DOI: 10.1021/np400856h
    Two new acridone alkaloids, chlorospermines A and B (1 and 2), were isolated from the stem bark of Glycosmis chlorosperma, together with the known atalaphyllidine (3) and acrifoline (4), by means of bioguided isolation using an in vitro enzyme assay against DYRK1A. Acrifoline (4) and to a lesser extent chlorospermine B (2) and atalaphyllidine (3) showed significant inhibiting activity on DYRK1A with IC50's of 0.075, 5.7, and 2.2 μM, respectively. Their selectivity profile was evaluated against a panel of various kinases, and molecular docking calculations provided structural details for the interaction between these compounds and DYRK1A.
  13. Islam MK, Saha S, Mahmud I, Mohamad K, Awang K, Jamal Uddin S, et al.
    J Ethnopharmacol, 2014 Feb 3;151(2):921-30.
    PMID: 24342778 DOI: 10.1016/j.jep.2013.11.056
    Madhupur forest area, Tangail is one of early human settlements in Bangladesh. Having abode in the vicinity of the forest, a strong ethnobotanical practice has prevailed in this area since ancient time. Due to the rapid deforestation during the last few decades, many plants have already disappeared or are facing extinction. Thus we attempted to document the medicinal plant use of Madhupur forest area with a view to preserve the ethnobotanical knowledge and in order to protect the biodiversity of this area.
  14. Kassim NK, Rahmani M, Ismail A, Sukari MA, Ee GC, Nasir NM, et al.
    Food Chem, 2013 Aug 15;139(1-4):87-92.
    PMID: 23561082 DOI: 10.1016/j.foodchem.2013.01.108
    The ethyl acetate and methanol bark extracts of Melicope glabra were evaluated for their antioxidant capacities by 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity and β-carotene bleaching/linoleic acid system. Both extracts exhibited strong inhibition against the DPPH radical (IC50 values of 24.81 and 13.01 μg ml(-1), respectively) and strong antioxidant activity in β-carotene bleaching assay. Both samples were found to have high phenolic content with values of 39 and 44 mg GAE/g as indicated by Follin-Ciocalteau's reagent. Antioxidant TLC assay-guided isolation on the methanol extract led to the isolation of a new pyranocoumarin, glabranin (1), umbelliferone (2), scopoletin (3) and sesamin (4), and their structures were determined by spectroscopy. Compounds (1-3) showed significant activities on DPPH free radical with the IC50 of 240.20, 810.02 and 413.19 μg ml(-1), respectively. However, in β-carotene bleaching assay, sesamin (4) showed higher inhibitory activity (1 mg ml(-1), 95%) than glabranin (1) (1 mg ml(-1), 74%), whilst umbelliferone (2) and scopoletin (3) were slightly pro-oxidant.
  15. In LL, Arshad NM, Ibrahim H, Azmi MN, Awang K, Nagoor NH
    PMID: 23043547 DOI: 10.1186/1472-6882-12-179
    Oral cancers although preventable, possess a low five-year survival rate which has remained unchanged over the past three decades. In an attempt to find a more safe, affordable and effective treatment option, we describe here the use of 1'S-1'-acetoxychavicol acetate (ACA), a component of Malaysian ginger traditionally used for various medicinal purposes.
  16. Phuah NH, In LL, Azmi MN, Ibrahim H, Awang K, Nagoor NH
    Reprod Sci, 2013 May;20(5):567-78.
    PMID: 23012319 DOI: 10.1177/1933719112459220
    The aims of this study were to investigate the combined effects of a natural compound 1'S-1'-acetoxychavicol acetate (ACA) with cisplatin (CDDP) on HPV-positive human cervical carcinoma cell lines (Ca Ski-low cisplatin sensitivity and HeLa-high cisplatin sensitivity), and to identify microRNAs (miRNAs) modulated in response toward ACA and/or CDDP. It was revealed that both ACA and CDDP induced dose- and time-dependent cytotoxicity when used as a stand-alone agent, while synergistic effects were observed when used in combination with a combination index (CI) value of 0.74 ± 0.01 and 0.85 ± 0.01 in Ca Ski and HeLa cells, respectively. A total of 25 miRNAs were found to be significantly differentially expressed in response to ACA and/or CDDP. These include hsa-miR-138, hsa-miR-210, and hsa-miR-744 with predicted gene targets involved in signaling pathways regulating apoptosis and cell cycle progression. In conclusion, ACA acts as a chemosensitizer which synergistically potentiates the cytotoxic effect of CDDP in cervical cancer cells. The altered miRNA expression upon administration of ACA and/or CDDP suggests that miRNAs play an important role in anticancer drug responses, which can be manipulated for therapeutic purposes.
  17. Awang K, Loong XM, Leong KH, Supratman U, Litaudon M, Mukhtar MR, et al.
    Fitoterapia, 2012 Dec;83(8):1391-5.
    PMID: 23098876 DOI: 10.1016/j.fitote.2012.10.004
    A study on the leaves of Aglaia exima led to the isolation of one new and seven known compounds: six triterpenoids and two steroids. Their structures were elucidated and analyzed mainly by using spectroscopic methods; 1D and 2D NMR, mass spectrometry, UV spectrometry and X-ray. All the triterpenoids and steroids were measured in vitro for their cytotoxic activities against eight cancer cell lines; lung (A549), prostate (DU-145), skin (SK-MEL-5), pancreatic (BxPC-3), liver (Hep G2), colon (HT-29), breast (MCF-7) and (MDA-MB-231). The new cycloartane triterpenoid, 24(E)-cycloart-24-ene-26-ol-3-one 1, showed potent cytotoxic activity against colon (HT-29) cancer cell line (IC(50) 11.5μM).
  18. Liew SY, Mukhtar MR, Hadi AH, Awang K, Mustafa MR, Zaima K, et al.
    Molecules, 2012 Apr 02;17(4):4028-36.
    PMID: 22469596 DOI: 10.3390/molecules17044028
    A new indole alkaloid, naucline (1) together with four known alkaloids, angustine (2), angustidine (3), nauclefine (4) and naucletine (5), were isolated from the bark of Nauclea officinalis. The structures of all isolated compounds were elucidated with various spectroscopic methods such as 1D- and 2D- NMR, IR, UV and LCMS-IT-TOF. In addition to that of alkaloid 1, the complete 13C-NMR data of naucletine (5) were also reported. Naucline (1) showed a moderate vasorelaxant activity (90% relaxation at 1 × 10(-5) M) whereas, angustine (2), nauclefine (4), and naucletine (5) showed potent vasorelaxant activity (more than 90% relaxation at 1 × 10(-5) M) on an isolated rat aorta.
  19. Hasan N, Osman H, Mohamad S, Chong WK, Awang K, Zahariluddin AS
    Pharmaceuticals (Basel), 2012;5(8):882-9.
    PMID: 24280680 DOI: 10.3390/ph5080882
    Three isoflavanoids, isovestitol (1), medicarpin (2), and sativan (3), along with another known compound, betulinic acid (4), were isolated from the root of Sesbania grandiflora. The structures of the isolated compounds were characterised by means of spectroscopic techniques (UV, IR, MS, 1H- and 13C-NMR, DEPT, COSY, HMQC, HMBC, and MS analysis). All the tested compounds 1-4 exhibited antituberculosis activity against Mycobacterium tuberculosis H37Rv, with MIC values of 50 µg/mL for compounds 1-3, and 100 µg/mL for compound 4, whereas, the methanol extract exhibited antituberculosis activity of 625 µg/mL. This is the first report on the occurrence of isoflavonoids in this plant and their antituberculosis activity.
  20. Nafiah MA, Mukhtar MR, Omar H, Ahmad K, Morita H, Litaudon M, et al.
    Molecules, 2011 Apr 20;16(4):3402-9.
    PMID: 21512448 DOI: 10.3390/molecules16043402
    A phytochemical study of the bark of Alseodaphne perakensis has yielded three aporphine alkaloids: the new compound N-cyanomethylnorboldine (1), and the two known alkaloids N-methyllaurotetanine (2) and norboldine (3). The isolation was achieved by chromatographic techniques and the structural elucidation was performed via spectral methods, notably 1D- and 2D-NMR, UV, IR, and HRFABMS. The vasorelaxation activity of compound 1 has been studied.
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