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Fulltext Research Priorities of Applying Low-Cost PM2.5 Sensors in Southeast Asian Countries

Lung SC, Thi Hien T, Cambaliza MOL, Hlaing OMT, Oanh NTK, Latif MT, et al.

Int J Environ Res Public Health, 2022 Jan 28;19(3).
PMID: 35162543 DOI: 10.3390/ijerph19031522

The low-cost and easy-to-use nature of rapidly developed PM2.5 sensors provide an opportunity to bring breakthroughs in PM2.5 research to resource-limited countries in Southeast Asia (SEA). This review provides an evaluation of the currently available literature and identifies research priorities in applying low-cost sensors (LCS) in PM2.5 environmental and health research in SEA. The research priority is an outcome of a series of participatory workshops under the umbrella of the International Global Atmospheric Chemistry Project-Monsoon Asia and Oceania Networking Group (IGAC-MANGO). A literature review and research prioritization are conducted with a transdisciplinary perspective of providing useful scientific evidence in assisting authorities in formulating targeted strategies to reduce severe PM2.5 pollution and health risks in this region. The PM2.5 research gaps that could be filled by LCS application are identified in five categories: source evaluation, especially for the distinctive sources in the SEA countries; hot spot investigation; peak exposure assessment; exposure-health evaluation on acute health impacts; and short-term standards. The affordability of LCS, methodology transferability, international collaboration, and stakeholder engagement are keys to success in such transdisciplinary PM2.5 research. Unique contributions to the international science community and challenges with LCS application in PM2.5 research in SEA are also discussed.
The Kuala Lumpur Qigong trial for women in the cancer survivorship phase-efficacy of a three-arm RCT to improve QOL

Loh SY, Lee SY, Murray L

Asian Pac J Cancer Prev, 2014;15(19):8127-34.
PMID: 25338995

BACKGROUND: Qigong is highly favoured among Asian breast cancer survivors for enhancing health. This study examined the hypothesis that quality of life (QoL) in the Qigong group is better than the placebo (aerobic) or usual care group.
MATERIALS AND METHODS: A total of 197 participants were randomly assigned to either the 8-week Kuala Lumpur Qigong Trial or control groups in 2010-2011. Measurement taken at baseline and post- intervention included QoL, distress and fatigue. Analysis of covariance (ANCOVA) and Kruskal Wallis were used to examine for differences between groups in the measurements.
RESULTS: There were 95 consenting participants in this 8week trial. The adherence rates were 63% for Qigong and 65% for the placebo group. The Qigong group showed significant marginal improvement in Quality of life scores compared to placebo (mean difference=7.3 unit; p=0.036), compared to usual care (mean difference=6.7 unit; p=0.048) on Functional Assessment Cancer Therapy-Breast measure. There were no significant changes between the placebo and usual care groups in fatigue or distress at post intervention (8-week).
CONCLUSIONS: Cancer survivors who participated in the Qigong intervention showed slightly better QOL. Follow up studies are greatly needed to evaluate which subgroups may best benefit from Qigong. With a steep rise of cancer survivors, there is an urgent need to explore and engage more cultural means of physical activity to fight side effects of treatment and for cancer control in developing countries.
Quality of life in breast cancer survivors: 2 years post self-management intervention

Loh SY, Chew SL, Lee SY, Quek KF

Asian Pac J Cancer Prev, 2011;12(6):1497-501.
PMID: 22126488

INTRODUCTION: Today, cancer survivors have an added new role to self manage living with the medical, emotional and role tasks that can affect their quality of life (QOL). The purpose of the study was to evaluate the QOL of women two years after participating in a self-management intervention program.
METHOD: The clinical trial was conducted at University Malaya Medical Centre between 2006 and 2008. The experimental group underwent a 4-week self management program, and the control group underwent usual care. Two years after the intervention, questionnaires were randomly posted out to the participants.
RESULTS: A total of 51 questionnaires returned. There were statistically differences between groups in psychological, self-care, mobility and participation aspects in PIPP (p<0.05). The experimental group reported having higher confidence to live with breast cancer compared to control group (p<0.05). There were significant between-group changes in anxiety scores at T2 (immediately after intervention) to T4 (two years later), and the differences in anxiety scores within groups between time point T2 and T4 were significantly different (p<0.05).
CONCLUSION: The SAMA program is potentially capable to serve as a model intervention for successful transition to survivorship following breast cancer treatment. The program needs to be further tested for efficacy in a larger trial involving more diverse populations of women completing breast cancer treatment.
Qualitative experiences of breast cancer survivors on a self-management intervention: 2-year post-intervention

Loh SY, Ong L, Ng LL, Chew SL, Lee SY, Boniface G

Asian Pac J Cancer Prev, 2011;12(6):1489-95.
PMID: 22126487

BACKGROUND: Increasing survivorship warrants evidence-based intervention to help women manage living effectively with breast cancer. Breast cancer survivors may have many medical and psychosocial issues in the post- treatment period. Qualitative research was carried out to assess survivors' overall experience and if intervention helps in survivorship care. This paper reports exploration of benefit-findings from participation in an earlier 4-week self management intervention.
METHODS: We used a grounded theory approach to analyze three focus groups conducted between May and August 2010 in Kuala Lumpur. We used random sampling to recruit the informants (n=21), all of whom had earlier participated in the 4 week self-management program held two years previously.
FINDINGS: The women reported positive experience and growth with the self management program. Self-efficacy appears as an important underlying theme for successful experiences. The lack of proactive plans to provide bereavement support to surviving women was a key negative experience.
CONCLUSION: The intervention successfully brought women together to work in close partnership with health professionals on ways to self manage the medical, emotional and role task as they live indefinitely with breast cancer, a new chronic illness. The beneficial effect from the 4 week intervention was expressed by women even at 2 years after the program. Having successfully developed a tightly knitted group, a major oversight was the lack of professional support on bereavement for grieving members when close friends passed away.
Fulltext Barriers to exercise: perspectives from multiethnic cancer survivors in Malaysia

Loh SY, Chew SL, Lee SY

Asian Pac J Cancer Prev, 2011;12(6):1483-8.
PMID: 22126486

BACKGROUND: Many cancer survivors are still not active enough to reap the benefits of physical activity. This study aimed to explore the correlation between perceived barriers and participation in exercise among multi- ethnic Malaysian women with breast cancer.

METHODS: A cross-sectional study using a pre-post questionnaire and a media-clip as a cancer control strategy was conducted on a random sample of women with breast cancer. The tools were structured questionnaires to collect socio-medical demographic and physical activity data (e.g. barriers, exercise self-efficacy).

RESULTS: A statistically significant relationship between level of physical activity before and after diagnosis of breast cancer (n=51, χ2=70.14, p<0.01) was found, whereby participants who rated more hours of physical activity before diagnosis were likely to persevere with exercise after diagnosis, r(49)=0.73, p<01. Some 76.5% of women engaged in low level activity and 23.5% of the participants engaged in moderate level of physical activity.

CONCLUSIONS: Despite the many benefits of physical activity, the majority of survivors in this study were not found to be physically active, and did not even consciously think of exercise participation. Lack of time is the main barrier amongst those survivors who are predominantly 40-50 year old housewives juggling with household chores, childcare and/or job commitments. Public health messages stressing that short bouts of exercise or some exercise are better than no exercise needs to be emphasised consistently.
Fulltext Physical activity and women with breast cancer: insights from expert patients

Loh SY, Chew SL, Lee SY

Asian Pac J Cancer Prev, 2011;12(1):87-94.
PMID: 21517237

INTRODUCTION: Physical activity participation amongst cancer survivors is low. This potent modifiable host factor has been disregarded in the cancer treatment plan for decades, despite its role in cancer control. The purpose of this study was to explore perception of physical activity among women with breast cancer.
METHODS: Focus group with purposive sampling methods were conducted on women at different cancer trajectory - ie. completed treatment (n = 6) and undergoing treatment (n = 8). The taped discussions were transcribed verbatim and analyzed using a grounded theory approach. Concepts were identified as unique or shared between the two groups, and ordered into subcategories.
RESULTS AND DISCUSSION: Three key categories on barriers to exercise; facilitator/motivator towards exercise; and myths around exercise were highlighted. There were more myths and reservations about physical activity in the UT (undergoing treatment) group, than in the CT (completed-treatment) group. Facilitators included positive experience from physical activity engagement, easy-access to facility, and good social support.
CONCLUSIONS: Although both groups expressed difficulties in engaging in physical activity, the newly diagnosed have more negative perception of physical activity engagement. Both groups did not note the significant role of physical activity and cancer prevention/ recurrence, which is a key strategy to promote the uptake of exercise and acceptance of active lifestyle for cancer survivors. Health care clinicians like occupational therapists need to play greater public health role in educating and counseling lifestyle redesign for survivors living with cancer.
Barriers to participation in a randomized controlled trial of Qigong exercises amongst cancer survivors: lessons learnt

Loh SY, Lee SY, Quek KF, Murray L

Asian Pac J Cancer Prev, 2012;13(12):6337-42.
PMID: 23464455

BACKGROUND: Clinical trials on cancer subjects have one of the highest dropout rates. Barriers to recruitment range from patient-related, through institutional-related to staff-related factors. This paper highlights the low response rate and the recruitment barriers faced in our Qigong exercises trial.
MATERIALS AND METHOD: The Qigong trial is a three-arm trial with a priori power size of 114 patients for 80% power. The University Malaya Medical Centre database showed a total of 1,933 patients from 2006-2010 and 751 patients met our inclusion criteria. These patients were approached via telephone interview. 131 out of 197 patients attended the trial and the final response rate was 48% (n=95/197).
RESULTS: Multiple barriers were identified, and were regrouped as patient- related, clinician-related and/or institutional related. A major consistent barrier was logistic difficulty related to transportation and car parking at the Medical Centre. conclusions: All clinical trials must pay considerable attention to the recruitment process and it should even be piloted to identify potential barriers and facilitators to reduce attrition rate in trials.
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.
Electrochemical genosensor assay using lyophilized gold nanoparticles/latex microsphere label for detection of Vibrio cholerae

Liew PS, Lertanantawong B, Lee SY, Manickam R, Lee YH, Surareungchai W

Talanta, 2015 Jul 1;139:167-73.
PMID: 25882423 DOI: 10.1016/j.talanta.2015.02.054

Vibrio cholerae is a Gram-negative bacterium that causes cholera, a diarrheal disease. Cholera is widespread in poor, under-developed or disaster-hit countries that have poor water sanitation. Hence, a rapid detection method for V. cholerae in the field under these resource-limited settings is required. In this paper, we describe the development of an electrochemical genosensor assay using lyophilized gold nanoparticles/latex microsphere (AuNPs-PSA) reporter label. The reporter label mixture was prepared by lyophilization of AuNPs-PSA-avidin conjugate with different types of stabilizers. The best stabilizer was 5% sorbitol, which was able to preserve the dried conjugate for up to 30 days. Three methods of DNA hybridization were compared and the one-step sandwich hybridization method was chosen as it was fastest and highly specific. The performance of the assay using the lyophilized reagents was comparable to the wet form for detection of 1aM to 1fM of linear target DNA. The assay was highly specific for V. cholerae, with a detection limit of 1fM of PCR products. The ability of the sensor is to detect LAMP products as low as 50ngµl(-1). The novel lyophilized AuNPs-PSA-avidin reporter label with electrochemical genosensor detection could facilitate the rapid on-site detection of V. cholerae.
Fulltext DNA barcoding for the identification and authentication of medicinal deer (Cervus sp.) products in China

Li W, Ren Q, Feng J, Lee SY, Liu Y

PLoS One, 2024;19(1):e0297164.
PMID: 38241246 DOI: 10.1371/journal.pone.0297164

Deer products from sika deer (Cervus nippon) and red deer (C. elaphus) are considered genuine and used for Traditional Chinese Medicine (TCM) materials in China. Deer has a very high economic and ornamental value, resulting in the formation of a characteristic deer industry in the prescription preparation of traditional Chinese medicine, health food, cosmetics, and other areas of development and utilization. Due to the high demand for deer products, the products are expensive and have limited production, but the legal use of deer is limited to only two species of sika deer and red deer; other wild deer are prohibited from hunting, so there are numerous cases of mixing and adulteration of counterfeit products and so on. There have been many reports that other animal (pig, cow, sheep, etc.) tissues or organs are often used for adulteration and confusion, resulting in poor efficacy of deer traditional medicine and trade fraud in deer products. To authenticate the deer products in a rapid and effective manner, the analysis used 22 deer products (antler, meat, bone, fetus, penis, tail, skin, and wool) that were in the form of blind samples. Total DNA extraction using a modified protocol successfully yielded DNA from the blind samples that was useful for PCR. Three candidate DNA barcoding loci, cox1, Cyt b, and rrn12, were evaluated for their discrimination strength through BLAST and phylogenetic clustering analyses. For the BLAST analysis, the 22 blind samples obtained 100% match identity across the three gene loci tested. It was revealed that 12 blind samples were correctly labeled for their species of origin, while three blind samples that were thought to originate from red deer were identified as C. nippon, and seven blind samples that were thought to originate from sika deer were identified as C. elaphus, Dama dama, and Rangifer tarandus. DNA barcoding analysis showed that all three gene loci were able to distinguish the two Cervus species and to identify the presence of adulterant species. The DNA barcoding technique was able to provide a useful and sensitive approach in identifying the species of origin in deer products.
Fulltext 4R of rubber waste management: current and outlook

Leong SY, Lee SY, Koh TY, Ang DT

J Mater Cycles Waste Manag, 2023;25(1):37-51.
PMID: 36466440 DOI: 10.1007/s10163-022-01554-y

Excessive accumulation of rubber waste necessitates the need to revisit the effectiveness of the existing rubber waste management system. This review provides an overview of the legislative frameworks, techniques, challenges, and trends of rubber waste management in various countries. The 4R (reduce, reuse, recycle and recover) framework applied in waste management system in some countries appears to be viable for the processing of rubber waste. Certain countries especially some of the European Union (EU) members have implemented extended producer responsibility (EPR) system to manage the collection of rubber waste, particularly used tires. The processing of rubber waste in each level of the 4R hierarchy was then discussed, with detailed elaboration on the most practiced 'R', recycling which encompasses the direct recycling of products, as well as material recycling via physical and/or chemical means. The challenges faced in the implementation of rubber waste management system in different countries were highlighted and recommendations for a more sustainable rubber consumption were provided at the end of this review.
Genetic and immunologic relationships between vaccine and field strains for vaccine selection of type A foot-and-mouth disease virus circulating in East Asia

Lee SY, Park ME, Kim RH, Ko MK, Lee KN, Kim SM, et al.

Vaccine, 2015 Jan 29;33(5):664-9.
PMID: 25528521 DOI: 10.1016/j.vaccine.2014.12.007

Of the seven known serotypes of foot-and-mouth disease virus (FMDV), type A has the most diverse variations. Genetic variations also occur frequently at VP1, VP2, VP3, and VP4 because these proteins constitute the viral capsid. The structural proteins of FMDV, which are closely related to immunologic correlations, are the most easily analyzed because they have highly accessible information. In this study we analyzed the type A vaccine viruses by alignment of available sequences in order to find appropriate vaccine strains. The matching rate of ASIA topotype-specific sites (20 amino acids) located on the viral surface, which are mainly VP1 and VP2, was highly related to immunologic reactivity. Among the available vaccines analyzed in this study, we suggest that A Malaysia 97 could be used as a vaccine virus as it has the highest genetic similarity and immunologic aspects to field strains originating in East Asia.
DNA fluorescence shift sensor: a rapid method for the detection of DNA hybridization using silver nanoclusters

Lee SY, Hairul Bahara NH, Choong YS, Lim TS, Tye GJ

J Colloid Interface Sci, 2014 Nov 01;433:183-188.
PMID: 25129336 DOI: 10.1016/j.jcis.2014.07.033

DNA-templated silver nanoclusters (AgNC) are a class of subnanometer sized fluorophores with good photostability and brightness. It has been applied as a diagnostic tool mainly for deoxyribonucleic acid (DNA) detection. Integration of DNA oligomers to generate AgNCs is interesting as varying DNA sequences can result in different fluorescence spectra. This allows a simple fluorescence shifting effect to occur upon DNA hybridization with the hybridization efficiency being a pronominal factor for successful shifting. The ability to shift the fluorescence spectra as a result of hybridization overcomes the issue of background intensities in most fluorescent based assays. Here we describe an optimized method for the detection of single-stranded and double-stranded synthetic forkhead box P3 (FOXP3) target by hybridization with the DNA fluorescence shift sensor. The system forms a three-way junction by successful hybridization of AgNC, G-rich strand (G-rich) to the target DNA, which generated a shift in fluorescence spectra with a marked increase in fluorescence intensity. The DNA fluorescence shift sensor presents a rapid and specific alternative to conventional DNA detection.
N-O, carboxymethyl chitosan enhanced scaffold porosity and biocompatibility under e-beam irradiation at 50 kGy

Lee SY, Kamarul T

Int J Biol Macromol, 2014 Mar;64:115-22.
PMID: 24325858 DOI: 10.1016/j.ijbiomac.2013.11.039

In this study, a chitosan co-polymer scaffold was prepared by mixing poly(vinyl alcohol) (PVA), NO, carboxymethyl chitosan (NOCC) and polyethylene glycol (PEG) solutions to obtain desirable properties for chondrocyte cultivation. Electron beam (e-beam) radiation was used to physically cross-link these polymers at different doses (30 kGy and 50 kGy). The co-polymers were then lyophilized to form macroporous three-dimensional (3-D) matrix. Scaffold morphology, porosity, swelling properties, biocompatibility, expression of glycosaminoglycan (GAG) and type II collagen following the seeding of primary chondrocytes were studied up to 28 days. The results demonstrate that irradiation of e-beam at 50 kGy increased scaffold porosity and pore sizes subsequently enhanced cell attachment and proliferation. Scanning electron microscopy and transmission electron microscopy revealed extensive interconnected microstructure of PVA-PEG-NOCC, demonstrated cellular activities on the scaffolds and their ability to maintain chondrocyte phenotype. In addition, the produced PVA-PEG-NOCC scaffolds showed superior swelling properties, and increased GAG and type II collagen secreted by the seeded chondrocytes. In conclusion, the results suggest that by adding NOCC and irradiation cross-linking at 50 kGy, the physical and biological properties of PVA-PEG blend can be further enhanced thereby making PVA-PEG-NOCC a potential scaffold for chondrocytes.
Supermacroporous poly(vinyl alcohol)-carboxylmethyl chitosan-poly(ethylene glycol) scaffold: an in vitro and in vivo pre-assessments for cartilage tissue engineering

Lee SY, Wee AS, Lim CK, Abbas AA, Selvaratnam L, Merican AM, et al.

J Mater Sci Mater Med, 2013 Jun;24(6):1561-70.
PMID: 23512151 DOI: 10.1007/s10856-013-4907-4

This study aims to pre-assess the in vitro and in vivo biocompatibility of poly(vinyl alcohol)-carboxylmethyl-chitosan-poly(ethylene glycol) (PCP) scaffold. PCP was lyophilised to create supermacroporous structures. 3-(4, 5-dimethyl-thiazol-2yl)-2, 5-diphenyltetrazolium bromide (MTT) assay and immunohistochemistry (IHC) were used to evaluate the effectiveness of PCP scaffolds for chondrocytes attachment and proliferation. The ultrastructural was assessed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Extracellular matrix (ECM) formation was evaluated using collagen type-II staining, glycosaminoglycan (GAG) and collagen assays. Histological analysis was conducted on 3-week implanted Sprague-Dawley rats. The MTT, IHC, SEM and TEM analyses confirm that PCP scaffolds promoted cell attachment and proliferation in vitro. The chondrocyte-PCP constructs secreted GAG and collagen type-II, both increased significantly from day-14 to day-28 (P
Unconfined compression properties of a porous poly(vinyl alcohol)-chitosan-based hydrogel after hydration

Lee SY, Pereira BP, Yusof N, Selvaratnam L, Yu Z, Abbas AA, et al.

Acta Biomater, 2009 Jul;5(6):1919-25.
PMID: 19289306 DOI: 10.1016/j.actbio.2009.02.014

A poly(vinyl alcohol) (PVA) hydrogel composite scaffold containing N,O-carboxymethylated chitosan (NOCC) was tested to assess its potential as a scaffold for cartilage tissue engineering in a weight-bearing environment. The mechanical properties under unconfined compression for different hydration periods were investigated. The effect of supplementing PVA with NOCC (20wt.% PVA:5vol.% NOCC) produced a porosity of 43.3% and this was compared against a non-porous PVA hydrogel (20g PVA: 100ml of water, control). Under non-hydrated conditions, the porous PVA-NOCC hydrogel behaved in a similar way to the control non-porous PVA hydrogel, with similar non-linear stress-strain response under unconfined compression (0-30% strain). After 7days' hydration, the porous hydrogel demonstrated a reduced stiffness (0.002kPa, at 25% strain), resulting in a more linear stiffness relationship over a range of 0-30% strain. Poisson's ratio for the hydrated non-porous and porous hydrogels ranged between 0.73 and 1.18, and 0.76 and 1.33, respectively, suggesting a greater fluid flow when loaded. The stress relaxation function for the porous hydrogel was affected by the hydration period (from 0 to 600s); however the percentage stress relaxation regained by about 95%, after 1200s for all hydration periods assessed. No significant differences were found between the different hydration periods between the porous hydrogels and control. The calculated aggregate modulus, H(A), for the porous hydrogel reduced drastically from 10.99kPa in its non-hydrated state to about 0.001kPa after 7days' hydration, with the calculated shear modulus reducing from 30.92 to 0.14kPa, respectively. The porous PVA-NOCC hydrogel conformed to a biphasic, viscoelastic model, which has the desired properties required for any scaffold in cartilage tissue engineering.
Fulltext Antioxidants and α-glucosidase inhibitors from Neptunia oleracea fractions using 1H NMR-based metabolomics approach and UHPLC-MS/MS analysis

Lee SY, Mediani A, Ismail IS, Maulidiani, Abas F

BMC Complement Altern Med, 2019 Jan 07;19(1):7.
PMID: 30616569 DOI: 10.1186/s12906-018-2413-4

BACKGROUND: Neptunia oleracea is a plant cultivated as vegetable in Southeast Asia. Previous works have revealed the potential of this plant as a source of natural antioxidants and α-glucosidase inhibitors. Continuing our interest on this plant, the present work is focused in identification of the bioactive compounds from different polarity fractions of N. oleracea, namely hexane (HF), chloroform (CF), ethyl acetate (EF) and methanol (MF).
METHODS: The N. oleracea fractions were obtained using solid phase extraction (SPE). A metabolomics approach that coupled the use of proton nuclear magnetic resonance (1H NMR) with multivariate data analysis (MVDA) was applied to distinguish the metabolite variations among the N. oleracea fractions, as well as to assess the correlation between metabolite variation and the studied bioactivities (DPPH free radical scavenging and α-glucosidase inhibitory activities). The bioactive fractions were then subjected to ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) analysis to profile and identify the potential bioactive constituents.
RESULTS: The principal component analysis (PCA) discriminated EF and MF from the other fractions with the higher distributions of phenolics. Partial least squares (PLS) analysis revealed a strong correlation between the phenolics and the studied bioactivities in the EF and the MF. The UHPLC-MS/MS profiling of EF and MF had tentatively identified the phenolics present. Together with some non-phenolic metabolites, a total of 37 metabolites were tentatively assigned.
CONCLUSIONS: The findings of this work supported that N. oleracea is a rich source of phenolics that can be potential antioxidants and α-glucosidase inhibitors for the management of diabetes. To our knowledge, this study is the first report on the metabolite-bioactivity correlation and UHPLC-MS/MS analysis of N. oleracea fractions.
Fulltext Momordica charantia Suppresses Inflammation and Glycolysis in Lipopolysaccharide-Activated RAW264.7 Macrophages

Lee SY, Wong WF, Dong J, Cheng KK

Molecules, 2020 Aug 20;25(17).
PMID: 32825228 DOI: 10.3390/molecules25173783

Macrophage activation is a key event that triggers inflammatory response. The activation is accompanied by metabolic shift such as upregulated glucose metabolism. There are accumulating evidences showing the anti-inflammatory activity of Momordica charantia. However, the effects of M. charantia on inflammatory response and glucose metabolism in activated macrophages have not been fully established. The present study aimed to examine the effect of M. charantia in modulating lipopolysaccharide (LPS)-induced inflammation and perturbed glucose metabolism in RAW264.7 murine macrophages. The results showed that LPS-induced NF-κB (p65) nuclear translocation was inhibited by M. charantia treatment. In addition, M. charantia was found to reduce the expression of inflammatory genes including IL6, TNF-α, IL1β, COX2, iNOS, and IL10 in LPS-treated macrophages. Furthermore, the data showed that M. charantia reduced the expression of GLUT1 and HK2 genes and lactate production (-28%), resulting in suppression of glycolysis. Notably, its effect on GLUT1 gene expression was found to be independent of LPS-induced inflammation. A further experiment also indicated that the bioactivities of M. charantia may be attributed to its key bioactive compound, charantin. Taken together, the study provided supporting evidences showing the potential of M. charantia for the treatment of inflammatory disorders.
Fulltext The complete chloroplast genome sequence of Chengal (Neobalanocarpus heimii, Dipterocarpaceae), a durable tropical hardwood

Lee SY, Ng WL, Hishamuddin MS, Mohamed R

Mitochondrial DNA B Resour, 2019;4(1):19-20.
PMID: 33365402 DOI: 10.1080/23802359.2018.1535848

Known for its durable timber quality, Neobalanocarpus heimii (King) Ashton is a highly sought after tree species endemic to the Malay Peninsula. Due to its scarcity and high value, the tree is classified under the IUCN Red List categories of Vulnerable. In this study, we assembled the complete chloroplast (cp) genome of N. heimii using data from high-throughput Illumina sequencing. The Chengal cp genome is 151,191 bp in size and includes two inverted repeat regions of 23,721 bp each, which is separated by a large single copy region of 83,801 bp and a small single copy region of 19,948 bp. A total of 130 genes were predicted, including 37 tRNA, 8 rRNA, and 85 protein-coding genes. Phylogenetic analysis placed N. heimii within the order Malvales.
Egg white lysozyme purification by a stirred cell contactor equipped with a weak ion-exchange nanofiber membrane: Process development and scale-up

Lee SY, Liu BL, Wu JY, Chang YK

Food Chem, 2021 Feb 15;338:128144.
PMID: 33092004 DOI: 10.1016/j.foodchem.2020.128144

A weak ion-exchange membrane (P-COOH) was synthesized by alkaline hydrolysis of a polyacrylonitrile nanofiber membrane prepared by electrospinning process. The P-COOH membrane was characterized for its physical properties and its application for purification of lysozyme from chicken egg white was investigated. The lysozyme adsorption efficiency of the P-COOH membrane operating in a stirred cell contactor (Millipore, Model 8010) was evaluated. The effects of key parameters such as the feed concentration, the rotating speed, the flow rate of feed and the operating pressure were studied. The results showed successful purification of lysozyme with a high recovery yield of 98% and a purification factor of 63 in a single step. The purification strategy was scaled-up to the higher feedstock loading volume of 32.7 and 70 mL using stirred cell contactors of Model 8050 and 8200, respectively. The scale-up processes achieved similar purification results, proving linear scalability of the purification technique adopted.

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