Displaying publications 61 - 80 of 128 in total

Abstract:
Sort:
  1. The complete chloroplast genome of Pandanus amaryllifolius Roxb. ex Lindl. (Pandanaceae) and its phylogenetic relationship
    Chin JH, Wong XJ, Chong TF, Muangkot P, Heng AT, Tanee T, et al.
    Mitochondrial DNA B Resour, 2024;9(4):541-545.
    PMID: 38665928 DOI: 10.1080/23802359.2024.2345773
    Pandanus amaryllifolius of Pandanaceae, a plant native to Southeast Asia, has been domesticated for its health benefits and aromatic leaves. It is also used for phytoremediation and soil rehabilitation. However, genetic studies of this species are limited. This study aims to expand its genomic information by assembling and characterizing the complete chloroplast genome of P. amaryllifolius. The chloroplast genome, which was 157,839 bp long, contains a total of 133 genes, including 87 protein-coding (CDS), 38 tRNA, and eight rRNA genes. The overall G/C content was 37.7%. A phylogenetic analysis using 79 shared unique CDS revealed a monophyletic relationship in Pandanales. Based on the limited sampling size, Pandanus amaryllifolius was the first to diverge in Pandanaceae. The genomic data will be useful for future phylogenetic and evolutionary studies of Pandanaceae.
  2. Comparative Analyses of Chloroplast Genome Provide Effective Molecular Markers for Species and Cultivar Identification in Bougainvillea
    Lin X, Lee SY, Ni J, Zhang X, Hu X, Zou P, et al.
    Int J Mol Sci, 2023 Oct 13;24(20).
    PMID: 37894819 DOI: 10.3390/ijms242015138
    Bougainvillea is popular in ornamental horticulture for its colorful bracts and excellent adaptability, but the complex genetic relationship among this genus is fuzzy due to limited genomic data. To reveal more genomic resources of Bougainvillea, we sequenced and assembled the complete chloroplast (cp) genome sequences of Bougainvillea spectabilis 'Splendens'. The cp genome size was 154,869 bp in length, containing 86 protein-coding genes, 38 tRNAs, and eight rRNAs. Cp genome comparison across 12 Bougainvillea species (B. spectabilis, B. glabra, B. peruviana, B. arborea, B. praecox, B. stipitata, B. campanulata, B. berberidifolia, B. infesta, B. modesta, B. spinosa, and B. pachyphylla) revealed five mutational hotspots. Phylogenetic analysis suggested that B. spectabilis published previously and B. glabra clustered into one subclade as two distinct groups, sister to the subclade of B. spectabilis 'Splendens'. We considered the phylogeny relationships between B. spectabilis and B. glabra to be controversial. Based on two hypervariable regions and three common plastid regions, we developed five molecular markers for species identification in Bougainvillea and applied them to classify 53 ornamental Bougainvillea cultivars. This study provides a valuable genetic resource for Bougainvillea breeding and offers effective molecular markers to distinguish the representative ornamental species of Bougainvillea.
  3. Highly divergent regions in the complete plastome sequences of Aquilaria are suitable for DNA barcoding applications including identifying species origin of agarwood products
    Hishamuddin MS, Lee SY, Syazwan SA, Ramlee SI, Lamasudin DU, Mohamed R
    3 Biotech, 2023 Mar;13(3):78.
    PMID: 36761338 DOI: 10.1007/s13205-023-03479-1
    Members of Aquilaria Lam. (Thymelaeaceae) are evergreen trees that are widely distributed in the Indomalesia region. Aquilaria is highly prized for its unique scented resin, agarwood, which is often the subject of unlawful trade activities. Survival of the tree is heavily threatened by destructive harvesting and agarwood poaching, leading to its protection under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Unfortunately, an efficient species identification method, which is crucial to aid in the conservation efforts of Aquilaria is lacking. Here, we described our search for a suitable specific DNA barcode for Aquilaria species using eight complete plastome sequences. We identified five highly variable regions (HVR) (matK-rps16, ndhF-rpl32, psbJ-petA, trnD, and trnT-trnL) in the plastomes. These regions were further analyzed using the neighbor-joining (NJ) method to assess their ability at discriminating the eight species. Coupled with in silico primer design, two potential barcoding regions, psbJ-petA and trnT-trnL, were identified. Their strengths in species delimitation were evaluated individually and in combination, via DNA barcoding analysis. Our findings showed that the combined dataset, psbJ-petA + trnT-trnL, effectively resolved members of the genus Aquilaria by clustering all species into their respective clades. In addition, we demonstrated that the newly proposed DNA barcode was capable at identifying the species of origin of six commercial agarwood samples that were included as unknown samples. Such achievement offers a new technical advancement, useful in the combat against illicit agarwood trades and in assisting the conservation of these valuable species in natural populations.

    SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-023-03479-1.

  4. Fulltext In Vitro Wound Healing Potential of Flavonoid C-Glycosides from Oil Palm (Elaeis guineensis Jacq.) Leaves on 3T3 Fibroblast Cells
    Che Zain MS, Lee SY, Sarian MN, Fakurazi S, Shaari K
    Antioxidants (Basel), 2020 Apr 17;9(4).
    PMID: 32316665 DOI: 10.3390/antiox9040326
    Oil palm (Elaeis guineensis Jacq.) leaves (OPL) are widely available at zero cost in Southeast Asia countries, especially in Malaysia and Indonesia due to large scale oil palm plantations. OPLs contain a large amount of flavonoids in particular flavonoid C-glycosides, which are known to possess useful biological properties including antioxidant and wound healing properties. The present study aimed at evaluating the wound healing efficacy of OPL in various solvent extracts and flavonoid enriched fractions and to determine the contribution of flavonoid C-glycosides (orientin, isoorientin, vitexin and isovitexin) using in-vitro scratch assay on 3T3 fibroblast cells. Solvent crude extracts with different polarity were screened and the most active extract was subjected to acid hydrolysis. The crude and acid hydrolysed extracts were further enriched using macroporous resins, XAD7HP. UHPLC-UV/PDA and LC-MS/MS analysis were applied for identification and confirmation of flavonoid C-glycosides. The wound healing properties comprised of cell viability, cell proliferation and cell migration were studied. Allantoin was used as a positive control to compare the efficacy among the tested samples. The results revealed all OPL crude extracts, flavonoid enriched fractions and flavonoid C-glycosides were non-toxic at concentrations below 25 µg/mL and showed better cell proliferation and migration activities at low concentrations than higher concentrations.. This study also demonstrated orientin, isoorientin, vitexin and isovitexin presented in OPL extracts and flavonoid enriched fractions stimulated proliferation and migration of 3T3 fibroblast cells. Hence, these findings may pose potential therapeutic bioactive agents for wound healing by enhancing fibroblast proliferation and migration.
  5. Fulltext Optimization of protein extraction from Chlorella Vulgaris via novel sugaring-out assisted liquid biphasic electric flotation system
    Koyande AK, Chew KW, Lim JW, Lee SY, Lam MK, Show PL
    Eng Life Sci, 2019 Dec;19(12):968-977.
    PMID: 32624986 DOI: 10.1002/elsc.201900068
    Microalgae biomass has been consumed as animal feed, fish feed and in human diet due to its high nutritional value. In this experiment, microalgae specie of Chlorella Vulgaris FSP-E was utilized for protein extraction via simple sugaring-out assisted liquid biphasic electric flotation system. The external electric force provided to the two-phase system assists in disruption of rigid microalgae cell wall and releases the contents of microalgae cell. This experiment manipulates various parameters to optimize the set-up. The liquid biphasic electric flotation set-up is compared with a control liquid biphasic flotation experiment without the electric field supply. The optimized separation efficiency of the liquid biphasic electric flotation system was 73.999 ± 0.739% and protein recovery of 69.665 ± 0.862% compared with liquid biphasic flotation, the separation efficiency was 61.584 ± 0.360% and protein recovery was 48.779 ± 0.480%. The separation efficiency and protein recovery for 5 × time scaled-up system was observed at 52.871 ± 1.236% and 73.294 ± 0.701%. The integration of simultaneous cell-disruption and protein extraction ensures high yield of protein from microalgae. This integrated method for protein extraction from microalgae demonstrated its potential and further research can lead this technology to commercialization.
  6. Fulltext Comparison of eight complete chloroplast genomes of the endangered Aquilaria tree species (Thymelaeaceae) and their phylogenetic relationships
    Hishamuddin MS, Lee SY, Ng WL, Ramlee SI, Lamasudin DU, Mohamed R
    Sci Rep, 2020 Aug 03;10(1):13034.
    PMID: 32747724 DOI: 10.1038/s41598-020-70030-0
    Aquilaria tree species are naturally distributed in the Indomalesian region and are protected against over-exploitation. They produce a fragrant non-timber product of high economic value, agarwood. Ambiguous species delimitation and limited genetic information within Aquilaria are among the impediments to conservation efforts. In this study, we conducted comparative analysis on eight Aquilaria species complete chloroplast (cp) genomes, of which seven were newly sequenced using Illumina HiSeq X Ten platform followed by de novo assembly. Aquilaria cp genomes possess a typical quadripartite structure including gene order and genomic structure. The length of each of the cp genome is about 174 kbp and encoded between 89 and 92 proteins, 38 tRNAs, and 8 rRNAs, with 27 duplicated in the IR (inverted repeat) region. Besides, 832 repeats (forward, reverse, palindrome and complement repeats) and nine highly variable regions were also identified. The phylogenetic analysis suggests that the topology structure of Aquilaria cp genomes were well presented with strong support values based on the cp genomes data set and matches their geographic distribution pattern. In summary, the complete cp genomes will facilitate development of species-specific molecular tools to discriminate Aquilaria species and resolve the evolutionary relationships of members of the Thymelaeaceae family.
  7. Machine Learning-Assisted Real-Time Polymerase Chain Reaction and High-Resolution Melt Analysis for SARS-CoV-2 Variant Identification
    Promja S, Puenpa J, Achakulvisut T, Poovorawan Y, Lee SY, Athamanolap P, et al.
    Anal Chem, 2023 Jan 12.
    PMID: 36633573 DOI: 10.1021/acs.analchem.2c05112
    Since the declaration of COVID-19 as a pandemic in early 2020, multiple variants of the severe acute respiratory syndrome-related coronavirus (SARS-CoV-2) have been detected. The emergence of multiple variants has raised concerns due to their impact on public health. Therefore, it is crucial to distinguish between different viral variants. Here, we developed a machine learning web-based application for SARS-CoV-2 variant identification via duplex real-time polymerase chain reaction (PCR) coupled with high-resolution melt (qPCR-HRM) analysis. As a proof-of-concept, we investigated the platform's ability to identify the Alpha, Delta, and wild-type strains using two sets of primers. The duplex qPCR-HRM could identify the two variants reliably in as low as 100 copies/μL. Finally, the platform was validated with 167 nasopharyngeal swab samples, which gave a sensitivity of 95.2%. This work demonstrates the potential for use as automated, cost-effective, and large-scale viral variant surveillance.
  8. Job satisfaction of foreign-educated nurses in Malaysia: A cross-sectional study
    Lee SY, Soh KL, Japar S, Ong SL, Soh KG, Tsujita Y
    Belitung Nurs J, 2021;7(5):361-369.
    PMID: 37496510 DOI: 10.33546/bnj.1682
    BACKGROUND: The transition process of migration to work abroad can be challenging and, depending on how it is handled, can impact the job satisfaction level of these foreign-educated nurses. A clear understanding of migrant nurses' job satisfaction is critical for effective translation of nursing practice across the health systems and cultures.

    OBJECTIVE: This study examined the job satisfaction of the foreign-educated nurses in Malaysia, which includes the job satisfaction dimensions and the significant difference between sociodemographic status and job satisfaction.

    METHODS: A cross-sectional survey of 102 foreign-educated nurses working in private hospitals, clinics, hemodialysis centers, nursing homes, and private homes in Malaysia was conducted from September 2017 to March 2018. Data were collected using a structured questionnaire. Descriptive statistics, Mann-Whitney U, and Kruskal Wallis tests were used to analyze the data.

    RESULTS: The study revealed that the participants had a median satisfaction score of 22 (IQR = 19 to 24). Serving the sick and needy and participants' self-respect were the highest satisfaction dimensions among the participants (Median = 3, IQR = 3 to 3). Moreover, the job satisfaction was significantly higher for registered foreign-educated nurses (mean rank = 62.5) than for unregistered foreign-educated nurses (mean rank = 48.65) when working in other countries (p = 0.02). Indian nurses (mean rank = 60.36) also expressed higher satisfaction in terms of working in other countries than Filipino nurses (mean rank = 46.88; p = 0.02). In addition, positive relationships with colleagues and superiors led to higher satisfaction among Indian nurses (mean rank = 61.02) than among Filipino nurses (mean rank = 47.24; p = 0.04). The job satisfaction of male foreign-educated nurses was significantly higher than their female counterparts in terms of self-respect, relationship with fellow nurses and superiors, working in other countries, career development, and ease of finding employment (p < 0.05).

    CONCLUSION: The overall job satisfaction among the foreign-educated nurses in Malaysia is high, mainly when serving the sick and needy, and their degree of self-respect. Understanding job satisfaction among foreign-educated nurses in Malaysia enables the management team to develop effective strategies for addressing nursing shortages and improving the quality of patient care.

  9. Direct recovery of malate dehydrogenase from highly turbid yeast cell homogenate using dye-ligand affinity chromatography in stirred fluidized bed
    Chen KH, Lee SY, Show PL, Hong SC, Chang YK
    J Chromatogr B Analyt Technol Biomed Life Sci, 2018 Nov 15;1100-1101:65-75.
    PMID: 30292951 DOI: 10.1016/j.jchromb.2018.09.039
    Dye-ligand affinity chromatography in a stirred fluidized bed has been developed for the rapid recovery of malate dehydrogenase (MDH) from highly turbid baker's yeast cell homogenate in a single step. The most suitable dye, namely Reactive Orange 4, in its optimal immobilized concentration of 8.78 mg/mL was immobilized onto high-density STREAMLINE matrix. To further examine optimal adsorption and elution conditions, the enzyme recovery operation was carried out using unclarified cell homogenates in stirred fluidized bed system. Aiming to develop a non-specific eluent, namely NaCl, to effectively elute the MDH adsorbed, direct recovery of MDH from highly turbid cell homogenate (50% w/v) in a stirred fluidized bed adsorption system was performed. The proposed system successfully achieved a recovery yield of 73.6% and a purification factor of 73.5 in a single step by using 0.6 M NaCl as an eluent at a high liquid velocity of 200 cm/h.
  10. Fulltext An Ultrasensitive Voltammetric Genosensor for the Detection of Bacteria Vibrio cholerae in Vegetable and Environmental Water Samples
    Futra D, Tan LL, Lee SY, Lertanantawong B, Heng LY
    Biosensors (Basel), 2023 Jun 04;13(6).
    PMID: 37366981 DOI: 10.3390/bios13060616
    In view of the presence of pathogenic Vibrio cholerae (V. cholerae) bacteria in environmental waters, including drinking water, which may pose a potential health risk to humans, an ultrasensitive electrochemical DNA biosensor for rapid detection of V. cholerae DNA in the environmental sample was developed. Silica nanospheres were functionalized with 3-aminopropyltriethoxysilane (APTS) for effective immobilization of the capture probe, and gold nanoparticles were used for acceleration of electron transfer to the electrode surface. The aminated capture probe was immobilized onto the Si-Au nanocomposite-modified carbon screen printed electrode (Si-Au-SPE) via an imine covalent bond with glutaraldehyde (GA), which served as the bifunctional cross-linking agent. The targeted DNA sequence of V. cholerae was monitored via a sandwich DNA hybridization strategy with a pair of DNA probes, which included the capture probe and reporter probe that flanked the complementary DNA (cDNA), and evaluated by differential pulse voltammetry (DPV) in the presence of an anthraquninone redox label. Under optimum sandwich hybridization conditions, the voltammetric genosensor could detect the targeted V. cholerae gene from 1.0 × 10-17-1.0 × 10-7 M cDNA with a limit of detection (LOD) of 1.25 × 10-18 M (i.e., 1.1513 × 10-13 µg/µL) and long-term stability of the DNA biosensor up to 55 days. The electrochemical DNA biosensor was capable of giving a reproducible DPV signal with a relative standard deviation (RSD) of <5.0% (n = 5). Satisfactory recoveries of V. cholerae cDNA concentration from different bacterial strains, river water, and cabbage samples were obtained between 96.5% and 101.6% with the proposed DNA sandwich biosensing procedure. The V. cholerae DNA concentrations determined by the sandwich-type electrochemical genosensor in the environmental samples were correlated to the number of bacterial colonies obtained from standard microbiological procedures (bacterial colony count reference method).
  11. Fulltext 1H NMR-Based Metabolomics Approach Revealing Metabolite Variation of Black Turmeric (Curcuma caesia) Extracts and Correlation with Its Antioxidant and α-Glucosidase Inhibitory Activities
    Ain Ibrahim NN, Kamal N, Mediani A, Sajak AAB, Lee SY, Shaari K, et al.
    Food Technol Biotechnol, 2023 Mar;61(1):107-117.
    PMID: 37200789 DOI: 10.17113/ftb.61.01.23.7711
    RESEARCH BACKGROUND: Curcuma species (Zingiberaceae) are well known medicinal herbs in India and Southeast Asia. Despite various findings reporting their beneficial biological activities, very little information has been recorded on the Curcuma caesia. Thus, this study aims to determine the phenolic content, antioxidant and α-glucosidase inhibitory activity of both rhizome and leaves of C. caesia.

    EXPERIMENTAL APPROACH: Rhizome and leaves of C. caesia were dried with oven (OD) and freeze (FD)-drying methods, and extracted with different Φ(ethanol,water)=100:0, 80:20, 50:50 and 0:100. The bioactivities of C. caesia extracts were evaluated using in vitro tests; total phenolic content (TPC), antioxidant (DPPH and FRAP) and α-glucosidase inhibitory activity. Proton nuclear magnetic resonance (1H NMR)-based metabolomics approach was employed to differentiate the most active extracts based on their metabolite profiles and correlation with bioactivities.

    RESULTS AND CONCLUSIONS: The FD rhizome extracted with Φ(ethanol,water)=100:0 was observed to have potent TPC expressed as gallic acid equivalents, FRAP expressed as Trolox equivalents and α-glucosidase inhibitory activity with values of (45.4±2.1) mg/g extract, (147.7±8.3) mg/g extract and (265.5±38.6) µg/mL (IC50), respectively. Meanwhile, for DPPH scavenging activity, the Φ(ethanol,water)=80:20 and 100:0 extracts of FD rhizome showed the highest activity with no significant difference between them. Hence, the FD rhizome extracts were selected for further metabolomics analysis. Principal component analysis (PCA) showed clear discrimination among the different extracts. Partial least square (PLS) analysis showed positive correlations of the metabolites, including xanthorrhizol derivative, 1-hydroxy-1,7-bis(4-hydroxy-3-methoxyphenyl)-(6E)-6-heptene-3,4-dione, valine, luteolin, zedoardiol, β-turmerone, selina-4(15),7(11)-dien-8-one, zedoalactone B and germacrone, with the antioxidant and α-glucosidase inhibition activities, whereas curdione and 1-(4-hydroxy-3,5-dimethoxyphenyl)-7-(4-hydroxy-3-methoxyphenyl)-(lE,6E)-1,6-heptadiene3,4-dione were correlated with α-glucosidase inhibitory activity.

    NOVELTY AND SCIENTIFIC CONTRIBUTION: C. caesia rhizome and leaf extracts contained phenolic compounds and had varies antioxidant and α-glucosidase inhibitory capacities. These findings strongly suggest that the rhizomes of C. caesia are an invaluable natural source of active ingredients for applications in pharmaceutical and food industries.

  12. High Carriage of tetA, sul1, sul2 and bla TEM Resistance Genes among the Multidrug-resistant Uropathogenic Escherichia coli (UPEC) Strains from Malaysian Patients
    Chin JJ, Lee HM, Lee SY, Lee YY, Chew CH
    Trop Life Sci Res, 2024 Jul;35(2):211-225.
    PMID: 39234470 DOI: 10.21315/tlsr2024.35.2.10
    The rapid emergence of multidrug-resistant (MDR) uropathogenic Escherichia coli (UPEC) strains pose a critical challenge in urinary tract infection (UTI) treatments. However, little work elucidated the resistance mechanisms of the MDR UPEC clinical strains in Malaysia. Therefore, this study aimed to determine the antimicrobial susceptibility profiles and the prevalence of antimicrobial resistance genes among the UPEC strains. Polymerase chain reactions were conducted to detect the presence of 6 antimicrobial resistance genes among 60 UPEC strains. Meanwhile, the antimicrobial resistance profiles against 9 antimicrobials were examined through the Kirby-Bauer disk diffusion method. In this study, the MDR isolates accounted for 40.0% (24/60), with the highest prevalence of resistance towards ampicillin (43/60; 71.7%), followed by tetracycline (31/60; 51.7%), nalidixic acid (30/60; 50.0%), co-trimoxazole (20/60, 33.3%), ciprofloxacin (19/60, 31.7%), levofloxacin (16/60, 21.6%) and chloramphenicol (10/60, 16.7%). In contrast, low resistance rates were observed among minocycline (1/60; 1.7%) and imipenem (0/60; 0.0%). bla TEM was the most prevalent gene (36/60; 60.0%), followed by tetA (27/60; 45.0%), sul2 (25/60; 41.7%), sul1 (13/60; 21.7%) and tetB (8/60; 13.3%). Surprisingly, bla SHV was not detected among the UPEC isolates. The MDR, ampicillin and tetracycline-resistant isolates were significantly associated with a higher prevalence of tetA, sul1, sul2 and bla TEM. In contrast, tetB displayed no significant relationship with any of the antimicrobials tested. The patient's age and gender were not the risk factors for the carriage of the resistance genes. Our findings identified the common resistance genes carried by the antimicrobial resistant UPEC isolates and provide valuable insights into developing the best antibiotic prescription regime to treat UTIs in our local scene.
  13. Optimising operating theatre (OT) efficiency while maintaining the standardised patient care in adolescent idiopathic scoliosis (AIS) surgery with the dedicated spine team approach: a specialised spine unit experience
    Lee SY, Chan CYW, Chiu CK, Chung WH, Hasan MS, Kwan MK
    Eur Spine J, 2024 Oct;33(10):3806-3813.
    PMID: 38861024 DOI: 10.1007/s00586-024-08352-0
    PURPOSE: To report the efficiency of OT utilisation and perioperative outcomes with a dedicated spine team approach in AIS patients who underwent posterior spinal fusion (PSF) surgeries in a consecutive case operation list.

    METHODS: Three AIS patients operated in a day (8:00 AM-8:00 PM) by a dedicated spine team were recruited between 2021 and 2022. The dedicated team comprised of three senior spine consultants who operated using a dual attending surgeon strategy, an anaesthetic consultant, dedicated surgical scrub nurses, anaesthesiology nurses, radiographers, and neuromonitoring technicians. Patients were categorised according to the sequence of operation list of the day (Case 1, Case 2, and Case 3). OT efficiency was represented by OT time in five stages (preoperative time, operative time, postoperative time, total OT time, and turnover time). OT time and perioperative outcomes were compared.

    RESULTS: 102 cases were analysed. On average, Case 1 began at 8:38 AM whereas Case 3 ended by 5:54 PM. OT efficiency was consistent throughout the day of operation with comparable OT time in all five stages between groups (p > 0.05). The mean turnover time was 15.1 ± 13.5 min and the mean operative time was 123.0 ± 28.1 min. Intraoperative arterial blood gas (ABG) parameters were maintained in an optimal range. The complication rate was 2.0% (N = 2/102).

    CONCLUSION: Consistent OT efficiency was demonstrated with a dedicated spine team approach. Despite performing three AIS cases in a consecutive case operation list, patients' safety was not compromised as perioperative outcomes between groups were comparable.

  14. Fulltext Diversity and Characterization of Endophytic Fungi Isolated From the Tropical Mangrove Species, Rhizophora mucronata, and Identification of Potential Antagonists Against the Soil-Borne Fungus, Fusarium solani
    Hamzah TNT, Lee SY, Hidayat A, Terhem R, Faridah-Hanum I, Mohamed R
    Front Microbiol, 2018;9:1707.
    PMID: 30090097 DOI: 10.3389/fmicb.2018.01707
    Rhizophora mucronata is an important ecosystem entity of the Malaysian mangrove forest. Since the species grows in a harsh environment, any organism that is isolated from this species would be of huge interest due to its potential in having novel bioactive compounds. In the present work, we isolated, identified and characterized, a total of 78 fungal isolates harboring inside the leaf tissues of R. mucronata. Molecular identification using the nuclear ribosomal DNA internal transcribe spacer (ITS) sequences returned with high similarity matches to known sequences in the GenBank. Maximum likelihood analysis revealed the phylogenetic relationship of all isolates from this study. Most of the dominating fungal endophytes were from the genera Pestalotiopsis, followed by Alternaria and Cladosporium. Six isolates representing the genera Alternaria, Fusarium, Nigrospora, Pestalotiopsis, Phoma, and Xylaria, were further screened for their antagonism activities. Dual culture test assay revealed their inhibition percentages against the phytopathogenic fungus Fusarium solani between 45-66%, and 0.8-23% when using non-volatile test assay. Of the six isolates, only Fusarium lateritium and Xylaria sp. showed antibacterial activities against the pathogenic bacteria, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus, with the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) ranging from 0.5 to 2 mg/mL. The DPPH radical scavenging assay recorded a high level of antioxidant activity in Xylaria sp., 3-fold above that of F. lateritium. We demonstrate for the first time, two members belonging to the endophytic fungal community in the tropical mangrove species that have potential use as antagonists and antibacterial agents for future biotechnological applications.
  15. Fulltext Metabolite Characterization and Correlations with Antioxidant and Wound Healing Properties of Oil Palm (Elaeis guineensis Jacq.) Leaflets via 1H-NMR-Based Metabolomics Approach
    Che Zain MS, Lee SY, Nasir NM, Fakurazi S, Shaari K
    Molecules, 2020 Nov 30;25(23).
    PMID: 33265992 DOI: 10.3390/molecules25235636
    Oil palm (Elaeis guineensis Jacq.) leaflets (OPLs) are one of the major agricultural by-products generated from the massive cultivation of Malaysian palm oil. This biomass is also reported to be of potential value based on its health-improving effects. By employing proton nuclear magnetic resonance (1H-NMR) spectroscopy combined with multivariate data analysis (MVDA), the metabolite profile of OPLs was characterized and correlated with their antioxidant and wound healing properties. Principal component analysis (PCA) classified four varieties of extracts, prepared using solvents ranging from polar to medium polarity, into three distinct clusters. Cumulatively, six flavonoids, eight organic acids, four carbohydrates, and an amine were identified from the solvent extracts. The more polar extracts, such as, the ethyl acetate-methanol, absolute methanol, and methanol-water, were richer in phytochemicals. Based on partial least square (PLS) analysis, the constituents in these extracts, such as (+)-catechin, (-)-epicatechin, orientin, isoorientin, vitexin, and isovitexin, were strongly correlated with the measured antioxidant activities, comprising ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and nitric oxide (NO) free radical scavenging activities, as well as with cell proliferation and migration activities. This study has provided crucial evidence on the importance of these natural antioxidant compounds on the wound healing properties of OPL.
  16. Fulltext DNA Barcoding of the Endangered Aquilaria (Thymelaeaceae) and Its Application in Species Authentication of Agarwood Products Traded in the Market
    Lee SY, Ng WL, Mahat MN, Nazre M, Mohamed R
    PLoS One, 2016;11(4):e0154631.
    PMID: 27128309 DOI: 10.1371/journal.pone.0154631
    The identification of Aquilaria species from their resinous non-wood product, the agarwood, is challenging as conventional techniques alone are unable to ascertain the species origin. Aquilaria is a highly protected species due to the excessive exploitation of its precious agarwood. Here, we applied the DNA barcoding technique to generate barcode sequences for Aquilaria species and later applied the barcodes to identify the source species of agarwood found in the market. We developed a reference DNA barcode library using eight candidate barcode loci (matK, rbcL, rpoB, rpoC1, psbA-trnH, trnL-trnF, ITS, and ITS2) amplified from 24 leaf accessions of seven Aquilaria species obtained from living trees. Our results indicated that all single barcodes can be easily amplified and sequenced with the selected primers. The combination of trnL-trnF+ITS and trnL-trnF+ITS2 yielded the greatest species resolution using the least number of loci combination, while matK+trnL-trnF+ITS showed potential in detecting the geographical origins of Aquilaria species. We propose trnL-trnF+ITS2 as the best candidate barcode for Aquilaria as ITS2 has a shorter sequence length compared to ITS, which eases PCR amplification especially when using degraded DNA samples such as those extracted from processed agarwood products. A blind test conducted on eight agarwood samples in different forms using the proposed barcode combination proved successful in their identification up to the species level. Such potential of DNA barcoding in identifying the source species of agarwood will contribute to the international timber trade control, by providing an effective method for species identification and product authentication.
  17. Fulltext Genome Size, Molecular Phylogeny, and Evolutionary History of the Tribe Aquilarieae (Thymelaeaceae), the Natural Source of Agarwood
    Farah AH, Lee SY, Gao Z, Yao TL, Madon M, Mohamed R
    Front Plant Sci, 2018;9:712.
    PMID: 29896211 DOI: 10.3389/fpls.2018.00712
    The tribe Aquilarieae of the family Thymelaeaceae consists of two genera, Aquilaria and Gyrinops, with a total of 30 species, distributed from northeast India, through southeast Asia and the south of China, to Papua New Guinea. They are an important botanical resource for fragrant agarwood, a prized product derived from injured or infected stems of these species. The aim of this study was to estimate the genome size of selected Aquilaria species and comprehend the evolutionary history of Aquilarieae speciation through molecular phylogeny. Five non-coding chloroplast DNA regions and a nuclear region were sequenced from 12 Aquilaria and three Gyrinops species. Phylogenetic trees constructed using combined chloroplast DNA sequences revealed relationships of the studied 15 members in Aquilarieae, while nuclear ribosomal DNA internal transcribed spacer (ITS) sequences showed a paraphyletic relationship between Aquilaria species from Indochina and Malesian. We exposed, for the first time, the estimated divergence time for Aquilarieae speciation, which was speculated to happen during the Miocene Epoch. The ancestral split and biogeographic pattern of studied species were discussed. Results showed no large variation in the 2C-values for the five Aquilaria species (1.35-2.23 pg). Further investigation into the genome size may provide additional information regarding ancestral traits and its evolution history.
  18. Detection of high-risk HPV 16 genotypes in cervical cancers using isothermal DNA amplification with electrochemical genosensor
    Nakowong P, Chatchawal P, Chaibun T, Boonapatcharoen N, Promptmas C, Buajeeb W, et al.
    Talanta, 2024 Mar 01;269:125495.
    PMID: 38043336 DOI: 10.1016/j.talanta.2023.125495
    Cervical cancer emerges as the third most prevalent types of malignancy among women on a global scale. Cervical cancer is significantly associated with the persistent infection of human papillomavirus (HPV) type 16. The process of diagnosing is crucial in order to prevent the progression of a condition into a malignant state. The early detection of cervical cancer through initial stage screening is of the utmost significance in both the prevention and effective management of this disease. The present detection methodology is dependent on quantitative polymerase chain reaction (qPCR), which necessitates the use of a costly heat cycler instrument. In this study, we report the development of an electrochemical DNA biosensor integrated with an isothermal recombinase polymerase amplification (RPA) reaction for the detection and identification of the high-risk HPV-16 genotype. The electrochemical biosensor exhibited a high degree of specificity and sensitivity, as evidenced by its limit of detection (LOD) of 0.23 copies/μL of HPV-16 DNA. The validity of this electrochemical platform was confirmed through the analysis of 40 cervical tissues samples, and the findings were consistent with those obtained through polymerase chain reaction (PCR) testing. Our straightforward electrochemical detection technology and quick turnaround time at 75 min make the assay suitable for point-of-care testing in low-resource settings.
  19. Fulltext Quantitative Analysis and Human Health Risk Assessment of Heavy Metals in Paddy Plants Collected from Perak, Malaysia
    Sibuar AA, Zulkafflee NS, Selamat J, Ismail MR, Lee SY, Abdull Razis AF
    Int J Environ Res Public Health, 2022 Jan 10;19(2).
    PMID: 35055550 DOI: 10.3390/ijerph19020731
    Rice is one of the major crops as well as the staple food in Malaysia. However, historical mining activity has raised a concern regarding heavy metal contamination in paddy plants, especially in Perak, a state with major tin mining during the late nineteenth century. Therefore, the objective of this study is to investigate the heavy metals (As, Cd, Pb, Cu, Cr) contamination in paddy soils and paddy plants in three districts in Perak. The content of heavy metals was determined using ICP-MS, while the absorption and transferability of heavy metals in the paddy plants were investigated through enrichment (EF) and translocation (TF) factors. Principal component analysis (PCA) was employed to recognize the pattern of heavy metal contaminations in different sampling areas. Health risk assessment was performed through calculation of various indices. The quantification results showed that root contained highest concentration of the studied heavy metals, with As exhibiting the highest concentration. The EF results revealed the accumulation of As, Cu, and Cr in the rice grains while PCA showed the different compositional pattern in the different sampling areas. The health risk assessment disclosed both noncarcinogenic and carcinogenic risks in the local adults and children. Overall, findings from this study show that heavy metal contamination poses potential health risks to the residents and control measure is required.
  20. Fulltext Unveiling the enigma of blind box impulse buying curiosity: The moderating role of price consciousness
    Gong X, Yee CL, Lee SY, Saif ANM, Liu M, Anonthi F
    Heliyon, 2024 Dec 30;10(24):e40564.
    PMID: 39759335 DOI: 10.1016/j.heliyon.2024.e40564
    This study explores the causes of curiosity-driven impulse buying in blind boxes using the Stimulus-Organism-Response (S-O-R) model and adaptation level theory. It examines how store environment and product factors contribute to customer curiosity, incorporating price consciousness into the overall framework. Insights from an online survey of 306 Chinese respondents indicate that environmental factors and specific product characteristics positively influence consumer curiosity, while price consciousness has a negative moderate effect. The findings also show that customer curiosity stimulates impulse buying behavior and mediates the relationship between store atmosphere, surprise, and perceived novelty. This study identifies both objective and subjective factors behind blind box impulse buying and offers relevant suggestions for governments and consumers on managing impulse buying.
Related Terms
    Try searching for something
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links