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Dive into the research topics where Sri Nurestri Abd Malek is active.

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Featured researches published by Sri Nurestri Abd Malek.


Evidence-based Complementary and Alternative Medicine | 2013

In Vitro Morphological Assessment of Apoptosis Induced by Antiproliferative Constituents from the Rhizomes of Curcuma zedoaria

Syarifah Nur Syed Abdul Rahman; Norhanom Abdul Wahab; Sri Nurestri Abd Malek

Bioassay-guided isolation of the active hexane fractions of Curcuma zedoaria led to the identification of five pure compounds, namely, curzerenone (1), neocurdione (2), curdione (3), alismol (4), and zederone (5) and a mixture of sterols, namely, campesterol (6), stigmasterol (7), and β-sitosterol (8). Alismol has never been reported to be present in Curcuma zedoaria. All isolated compounds except (3) were evaluated for their cytotoxic activity against MCF-7, Ca Ski, and HCT-116 cancer cell lines and noncancer human fibroblast cell line (MRC-5) using neutral red cytotoxicity assay. Curzerenone and alismol significantly inhibited cell proliferation in human cancer cell lines MCF-7, Ca Ski, and HCT-116 in a dose-dependent manner. Cytological observations by an inverted phase contrast microscope and Hoechst 33342/PI dual-staining assay showed typical apoptotic morphology of cancer cells upon treatment with curzerenone and alismol. Both compounds induce apoptosis through the activation of caspase-3. It can thus be suggested that curzerenone and alismol are modulated by apoptosis via caspase-3 signalling pathway. The findings of the present study support the use of Curcuma zedoaria rhizomes in traditional medicine for the treatment of cancer-related diseases. Thus, two naturally occurring sesquiterpenoids, curzerenone and alismol, hold great promise for use in chemopreventive and chemotherapeutic strategies.Bioassay-guided isolation of the active hexane fractions of Curcuma zedoaria led to the identification of five pure compounds, namely, curzerenone (1), neocurdione (2), curdione (3), alismol (4), and zederone (5) and a mixture of sterols, namely, campesterol (6), stigmasterol (7), and β-sitosterol (8). Alismol has never been reported to be present in Curcuma zedoaria. All isolated compounds except (3) were evaluated for their cytotoxic activity against MCF-7, Ca Ski, and HCT-116 cancer cell lines and noncancer human fibroblast cell line (MRC-5) using neutral red cytotoxicity assay. Curzerenone and alismol significantly inhibited cell proliferation in human cancer cell lines MCF-7, Ca Ski, and HCT-116 in a dose-dependent manner. Cytological observations by an inverted phase contrast microscope and Hoechst 33342/PI dual-staining assay showed typical apoptotic morphology of cancer cells upon treatment with curzerenone and alismol. Both compounds induce apoptosis through the activation of caspase-3. It can thus be suggested that curzerenone and alismol are modulated by apoptosis via caspase-3 signalling pathway. The findings of the present study support the use of Curcuma zedoaria rhizomes in traditional medicine for the treatment of cancer-related diseases. Thus, two naturally occurring sesquiterpenoids, curzerenone and alismol, hold great promise for use in chemopreventive and chemotherapeutic strategies.


Frontiers in Microbiology | 2015

Presence of antioxidative agent, Pyrrolo[1,2-a]pyrazine-1,4-dione, hexahydro- in newly isolated Streptomyces mangrovisoli sp. nov.

Hooi-Leng Ser; Uma D. Palanisamy; Wai-Fong Yin; Sri Nurestri Abd Malek; Kok-Gan Chan; Bey-Hing Goh; Learn-Han Lee

A novel Streptomyces, strain MUSC 149T was isolated from mangrove soil. A polyphasic approach was used to study the taxonomy of MUSC 149T, which shows a range of phylogenetic and chemotaxonomic properties consistent with those of the members of the genus Streptomyces. The diamino acid of the cell wall peptidoglycan was LL-diaminopimelic acid. The predominant menaquinones were identified as MK9(H8) and MK9(H6). Phylogenetic analysis indicated that closely related strains include Streptomyces rhizophilus NBRC 108885T (99.2% sequence similarity), S. gramineus NBRC 107863T (98.7%) and S. graminisoli NBRC 108883T (98.5%). The DNA–DNA relatedness values between MUSC 149T and closely related type strains ranged from 12.4 ± 3.3% to 27.3 ± 1.9%. The DNA G + C content was determined to be 72.7 mol%. The extract of MUSC 149T exhibited strong antioxidant activity and chemical analysis reported identification of an antioxidant agent, Pyrrolo[1,2-a]pyrazine-1,4-dione, hexahydro-. These data showed that metabolites of MUSC 149T shall be useful as preventive agent against free-radical associated diseases. Based on the polyphasic study of MUSC 149T, the strain merits assignment to a novel species, for which the name S. mangrovisoli sp. nov. is proposed. The type strain is MUSC 149T (=MCCC 1K00699T=DSM 100438T).


Journal of Agricultural and Food Chemistry | 2011

Chemical composition and antioxidant properties of extracts of fresh fruiting bodies of pleurotus sajor-caju (Fr.) singer

Gowri Kanagasabapathy; Sri Nurestri Abd Malek; Umah Rani Kuppusamy; S. Vikineswary

The chemical composition and in vitro antioxidant activity of aqueous butanol and ethyl acetate extracts of Pleurotus sajor-caju were investigated in this study. Twenty-two compounds comprising methyl esters, hydrocarbon fatty acids, ethyl esters, and sterols were identified in ethyl acetate extracts, while cinnamic acid, nicotinamide, benzeneacetamide, and 4-hydroxybenzaldyhde were identified in butanol extracts by gas chromatography-mass spectrometry and NMR analysis. The antioxidant activity was determined by a β-carotene bleaching method, ferric reducing antioxidant power, trolox equivalent antioxidant capacity, and lipid peroxidation assays, while the total phenolic content in P. sajor-caju was assessed by Folin-Ciocalteaus method. The aqueous and butanol extracts exhibited the highest antioxidant activity, corresponding to the total phenolic content. The subfractions from the ethyl acetate extract (EP1, EP2, EP3, and EP4), however, showed moderate antioxidant activity. The regular consumption of P. sajor-caju as a part of our diet may render nutritional and nutraceuticals benefits for good health.


Frontiers in Microbiology | 2016

Streptomyces antioxidans sp. nov., a Novel Mangrove Soil Actinobacterium with Antioxidative and Neuroprotective Potentials.

Hooi-Leng Ser; Loh Teng-Hern Tan; Uma D. Palanisamy; Sri Nurestri Abd Malek; Wai-Fong Yin; Kok-Gan Chan; Bey-Hing Goh; Learn-Han Lee

A novel strain, Streptomyces antioxidans MUSC 164T was recovered from mangrove forest soil located at Tanjung Lumpur, Malaysia. The Gram-positive bacterium forms yellowish-white aerial and brilliant greenish yellow substrate mycelium on ISP 2 agar. A polyphasic approach was used to determine the taxonomy status of strain MUSC 164T. The strain showed a spectrum of phylogenetic and chemotaxonomic properties consistent with those of the members of the genus Streptomyces. The cell wall peptidoglycan was determined to contain LL-diaminopimelic acid. The predominant menaquinones were identified as MK-9(H6) and MK-9(H8), while the identified polar lipids consisted of aminolipid, diphosphatidylglycerol, glycolipid, hydroxyphosphatidylethanolamine, phospholipid, phosphatidylinositol, phosphatidylethanolamine, phosphatidylglycerol and lipid. The cell wall sugars consist of galactose, glucose and ribose. The predominant cellular fatty acids (>10.0%) were identified as iso-C15:0 (34.8%) and anteiso-C15:0(14.0%). Phylogenetic analysis identified that closely related strains for MUSC 164T as Streptomyces javensis NBRC 100777T (99.6% sequence similarity), Streptomyces yogyakartensis NBRC 100779T (99.6%) and Streptomyces violaceusniger NBRC 13459T (99.6%). The DNA–DNA relatedness values between MUSC 164T and closely related type strains ranged from 23.8 ± 0.3% to 53.1 ± 4.3%. BOX-PCR fingerprints comparison showed that MUSC 164T exhibits a unique DNA profile, with DNA G + C content determined to be 71.6 mol%. Based on the polyphasic study of MUSC 164T, it is concluded that this strain represents a novel species, for which the name Streptomyces antioxidans sp. nov. is proposed. The type strain is MUSC 164T (=DSM 101523T = MCCC 1K01590T). The extract of MUSC 164T showed potent antioxidative and neuroprotective activities against hydrogen peroxide. The chemical analysis of the extract revealed that the strain produces pyrazines and phenolic-related compounds that could explain for the observed bioactivities.


BMC Complementary and Alternative Medicine | 2014

Phytochemical constituents, nutritional values, phenolics, flavonols, flavonoids, antioxidant and cytotoxicity studies on Phaleria macrocarpa (Scheff.) Boerl fruits.

Ma Ma Lay; Saiful Anuar Karsani; Sadegh Mohajer; Sri Nurestri Abd Malek

BackgroundThe edible fruits of Phaleria macrocarpa (Scheff.) Boerl are widely used in traditional medicine in Indonesia. It is used to treat a variety of medical conditions such as - cancer, diabetes mellitus, allergies, liver and heart diseases, kidney failure, blood diseases, high blood pressure, stroke, various skin diseases, itching, aches, and flu. Therefore, it is of great interest to determine the biochemical and cytotoxic properties of the fruit extracts.MethodsThe methanol, hexane, chloroform, ethyl acetate, and water extracts of P. macrocarpa fruits were examined for phytochemicals, physicochemicals, flavonols, flavonoids and phenol content. Its nutritional value (A.O.A.C method), antioxidant properties (DPPH assay) and cytotoxicity (MTT cell proliferation assay) were also determined.ResultsA preliminary phyotochemical screening of the different crude extracts from the fruits of P. macrocarpa showed the presence secondary metabolites such as of flavonoids, phenols, saponin glycosides and tannins. The ethyl acetate and methanol extracts displayed high antioxidant acitivity (IC50 value of 8.15±0.02 ug/mL) in the DPPH assay comparable to that of the standard gallic acid (IC50 value of 10.8±0.02 ug/mL). Evaluation of cytotoxic activity showed that the crude methanol extract possessed excellent anti-proliferative activity against SKOV-3 (IC50 7.75±2.56 μg/mL) after 72 hours of treatment whilst the hexane and ethyl acetate extracts displayed good cytotoxic effect against both SKOV-3 and MDA-MB231 cell lines. The chloroform extract however, showed selective inhibitory activity in the breast cancer cell line MDA-MB231 (IC50 7.80±1.57 μg/mL) after 48 hours of treatment. There was no cytotoxic effect observed in the Ca Ski cell line and the two normal cell lines (MRC-5 and WRL-68).ConclusionThe methanol extract and the ethyl acetate fraction of P. macrocarpa fruits exhibited good nutritional values, good antioxidant and cytotoxic activities, and merits further investigation to identify the specific compound(s) responsible for these activities.


Evidence-based Complementary and Alternative Medicine | 2013

Beta-Glucan-Rich Extract from Pleurotus sajor-caju (Fr.) Singer Prevents Obesity and Oxidative Stress in C57BL/6J Mice Fed on a High-Fat Diet

Gowri Kanagasabapathy; Sri Nurestri Abd Malek; A. A. Mahmood; Kek Heng Chua; S. Vikineswary; Umah Rani Kuppusamy

Mushrooms have been used in folk medicine for thousands of years. In this study, the effect of β-glucan-rich extract of P. sajor-caju (GE) on lipid lowering and antioxidant potential was assessed in C57BL/6J mice fed on a high-fat diet. Obesity was induced in C57BL/6J mice by feeding a high-fat diet. The control groups in this study were ND (for normal diet) and HFD (for high-fat diet). The treated groups were ND240 (for normal diet) (240 mg/kg b.w) and HFD60, HFD120, and HFD240 (for high-fat diet), where the mice were administrated with three dosages of GE (60, 120, and 240 mg GE/kg b.w). Metformin (2 mg/kg b.w) served as positive control. GE-treated groups showed significantly reduced body weight, serum lipid, and liver enzymes levels. GE also attenuated protein carbonyl and lipid hydroperoxide levels by increasing the enzymic antioxidants (SOD, CAT, and GPx) activities in the mice. GE-treated groups induced the expression of hormone sensitive lipase (HSL) and adipose triglyceride lipase (ATGL) while downregulated the expression of peroxisome proliferator-activated receptor gamma (PPAR-γ), sterol regulatory binding protein-1c (SREBP-1c), and lipoprotein lipase (LPL). Hence, GE prevented weight gain in the mice by inducing lipolysis and may be valuable in the formulation of adjuvant therapy for obesity.


BMC Complementary and Alternative Medicine | 2012

Glucan-rich polysaccharides from Pleurotus sajor-caju (Fr.) Singer prevents glucose intolerance, insulin resistance and inflammation in C57BL/6J mice fed a high-fat diet

Gowri Kanagasabapathy; Umah Rani Kuppusamy; Sri Nurestri Abd Malek; Mahmood Ameen Abdulla; Kek Heng Chua; Vikineswary Sabaratnam

BackgroundPleurotus sajor-caju (P. sajor-caju) has been extremely useful in the prevention of diabetes mellitus due to its low fat and high soluble fiber content for thousands of years. Insulin resistance is a key component in the development of diabetes mellitus which is caused by inflammation. In this study, we aimed to investigate the in vivo efficacy of glucan-rich polysaccharide of P. sajor-caju (GE) against diabetes mellitus and inflammation in C57BL/6J mice fed a high-fat diet.MethodsDiabetes was induced in C57BL/6J mice by feeding a high-fat diet. The mice were randomly assigned to 7 groups (n=6 per group). The control groups in this study were ND (for normal diet) and HFD (for high-fat diet). The treated groups were ND240 (for normal diet) (240 mg/kg b.w) and HFD60, HFD120 and HFD240 (for high-fat), where the mice were administrated with three dosages of GE (60, 120, 240 mg GE/kg b.w respectively). Metformin (2 mg/kg b.w) served as positive control. The glucose tolerance test, glucose and insulin levels were measured at the end of 16 weeks. Expressions of genes for inflammatory markers, GLUT-4 and adiponectin in the adipose tissue of the mice were assessed. One-way ANOVA and Duncan’s multiple range tests (DMRT) were used to determine the significant differences between groups.ResultsGE treated groups improved the glucose tolerance, attenuated hyperglycemia and hyperinsulinemia in the mice by up-regulating the adiponectin and GLUT-4 gene expressions. The mice in GE treated groups did not develop insulin resistance. GE also down-regulated the expression of inflammatory markers (IL-6, TNF-α, SAA2, CRP and MCP-1) via attenuation of nuclear transcription factors (NF-κB).ConclusionGlucan-rich polysaccharide of P. sajor-caju can serve as a potential agent for prevention of glucose intolerance, insulin resistance and inflammation.


The Scientific World Journal | 2014

Cytotoxic Constituents from the Rhizomes of Curcuma zedoaria

Omer Abdalla Ahmed Hamdi; Syarifah Nur Syed Abdul Rahman; Khalijah Awang; Norhanom Abdul Wahab; Chung Yeng Looi; Noel F. Thomas; Sri Nurestri Abd Malek

Curcuma zedoaria also known as Temu putih is traditionally used in food preparations and treatment of various ailments including cancer. The cytotoxic activity of hexane, dichloromethane, ethyl acetate, methanol, and the methanol-soxhlet extracts of Curcuma zedoaria rhizomes was tested on two human cancer cell lines (Ca Ski and MCF-7) and a noncancer cell line (HUVEC) using MTT assay. Investigation on the chemical components in the hexane and dichloromethane fractions gave 19 compounds, namely, labda-8(17),12 diene-15,16 dial (1), dehydrocurdione (2), curcumenone (3), comosone II (4), curcumenol (5), procurcumenol (6), germacrone (7), zerumbone epoxide (8), zederone (9), 9-isopropylidene-2,6-dimethyl-11-oxatricyclo[6.2.1.01,5]undec-6-en-8-ol (10), furanodiene (11), germacrone-4,5-epoxide (12), calcaratarin A (13), isoprocurcumenol (14), germacrone-1,10-epoxide (15), zerumin A (16), curcumanolide A (17), curcuzedoalide (18), and gweicurculactone (19). Compounds (1–19) were evaluated for their antiproliferative effect using MTT assay against four cancer cell lines (Ca Ski, MCF-7, PC-3, and HT-29). Curcumenone (3) and curcumenol (5) displayed strong antiproliferative activity (IC50 = 8.3 ± 1.0 and 9.3 ± 0.3 μg/mL, resp.) and were found to induce apoptotic cell death on MCF-7 cells using phase contrast and Hoechst 33342/PI double-staining assay. Thus, the present study provides basis for the ethnomedical application of Curcuma zedoaria in the treatment of breast cancer.


Evidence-based Complementary and Alternative Medicine | 2015

Xanthohumol Induces Growth Inhibition and Apoptosis in Ca Ski Human Cervical Cancer Cells

Wai Kuan Yong; Sri Nurestri Abd Malek

We investigate induction of apoptosis by xanthohumol on Ca Ski cervical cancer cell line. Xanthohumol is a prenylated chalcone naturally found in hop plants, previously reported to be an effective anticancer agent in various cancer cell lines. The present study showed that xanthohumol was effective to inhibit proliferation of Ca Ski cells based on IC50 values using sulforhodamine B (SRB) assay. Furthermore, cellular and nuclear morphological changes were observed in the cells using phase contrast microscopy and Hoechst/PI fluorescent staining. In addition, 48-hour long treatment with xanthohumol triggered externalization of phosphatidylserine, changes in mitochondrial membrane potential, and DNA fragmentation in the cells. Additionally, xanthohumol mediated S phase arrest in cell cycle analysis and increased activities of caspase-3, caspase-8, and caspase-9. On the other hand, Western blot analysis showed that the expression levels of cleaved PARP, p53, and AIF increased, while Bcl-2 and XIAP decreased in a dose-dependent manner. Taken together, these findings indicate that xanthohumol-induced cell death might involve intrinsic and extrinsic apoptotic pathways, as well as downregulation of XIAP, upregulation of p53 proteins, and S phase cell cycle arrest in Ca Ski cervical cancer cells. This work suggests that xanthohumol is a potent chemotherapeutic candidate for cervical cancer.


The Scientific World Journal | 2014

Essential Oil Content of the Rhizome of Curcuma purpurascens Bl. (Temu Tis) and Its Antiproliferative Effect on Selected Human Carcinoma Cell Lines

Sok-Lai Hong; Guan-Serm Lee; Syarifah Nur Syed Abdul Rahman; Omer Abdalla Ahmed Hamdi; Khalijah Awang; Nurfina Aznam Nugroho; Sri Nurestri Abd Malek

Curcuma purpurascens Bl., belonging to the Zingiberaceae family, is known as temu tis in Yogyakarta, Indonesia. In this study, the hydrodistilled dried ground rhizome oil was investigated for its chemical content and antiproliferative activity against selected human carcinoma cell lines (MCF7, Ca Ski, A549, HT29, and HCT116) and a normal human lung fibroblast cell line (MRC5). Results from GC-MS and GC-FID analysis of the rhizome oil of temu tis showed turmerone as the major component, followed by germacrone, ar-turmerone, germacrene-B, and curlone. The rhizome oil of temu tis exhibited strong cytotoxicity against HT29 cells (IC50 value of 4.9 ± 0.4 μg/mL), weak cytotoxicity against A549, Ca Ski, and HCT116 cells (with IC50 values of 46.3 ± 0.7, 32.5 ± 1.1, and 35.0 ± 0.3 μg/mL, resp.), and no inhibitory effect against MCF7 cells. It exhibited mild cytotoxicity against a noncancerous human lung fibroblast cell line (MRC5), with an IC50 value of 25.2 ± 2.7 μg/mL. This is the first report on the chemical composition of this rhizomes oil and its selective antiproliferative effect on HT29. The obtained data provided a basis for further investigation of the mode of cell death.

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