Displaying publications 1 - 20 of 24 in total

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  1. Wong KH, Lal SK
    Virus Genes, 2023 Feb;59(1):25-35.
    PMID: 36260242 DOI: 10.1007/s11262-022-01935-3
    Influenza A (IAV) is a major human respiratory pathogen that contributes to a significant threat to health security, worldwide. Despite vaccinations and previous immunisations through infections, humans can still be infected with influenza several times throughout their lives. This phenomenon is attributed to the antigenic changes of hemagglutinin (HA) and neuraminidase (NA) proteins in IAV via genetic mutation and reassortment, conferring antigenic drift and antigenic shift, respectively. Numerous findings indicate that slow antigenic drift and reassortment-derived antigenic shift exhibited by IAV are key processes that allow IAVs to overcome the previously acquired host immunity, which eventually leads to the annual re-emergence of seasonal influenza and even pandemic influenza, in rare occasions. As a result, current therapeutic options hit a brick wall quickly. As IAV remains a constant threat for new outbreaks worldwide, the underlying processes of genetic changes and alternative antiviral approaches for IAV should be further explored to improve disease management. In the light of the above, this review discusses the characteristics and mechanisms of mutations and reassortments that contribute to IAV's evolution. We also discuss several alternative RNA-targeting antiviral approaches, namely the CRISPR/Cas13 systems, RNA interference (RNAi), and antisense oligonucleotides (ASO) as potential antiviral approaches against IAV.
  2. Wong KA, Lam SM, Sin JC
    J Nanosci Nanotechnol, 2019 08 01;19(8):5271-5278.
    PMID: 30913844 DOI: 10.1166/jnn.2019.16816
    Shaped-controlled ZnO architectures including spherical, rod, rice-like and flower-like were fabricated via a reflux method in which the morphology, crystallinity, functional group and optical properties were tailored under different pH values in the precursor solution. The photoactivities of the prepared ZnO were evaluated under UV irradiation and the findings implied that the flower-like ZnO synthesized at pH 12 displayed superior activities on palm oil mil effluent degradation than those of other structures. The photocatalytic enhancement of flower-like ZnO was ascribed to its unique architecture, good crystallinity and superior optical properties. The flower-like ZnO with excellent photocatalytic performance have been confirmed by formation of hydroxyl radicals using a terephthalic acid-photoluminescence test. There was an optimal photocatalyst amount of 1.0 g/L, at which a maximum chemical oxygen demand removal of palm oil mill effluent was achieved under exposure of UV light. The phytotoxicity experiment via mung beans demonstrated a decrease in phytotoxicity.
  3. Wong KA, Singh VA, Pailoor J
    Singapore Med J, 2013 Nov;54(11):e228-9.
    PMID: 24276110
    Intra-articular haemangioma is a rare and uncommon condition that sometimes presents in infants. The lesion can be a diagnostic challenge, with misdiagnosis often leading to delayed diagnosis and treatment. It is essential to establish and treat the condition early, as intra-articular haemangioma can lead to destruction of the joint and secondary arthrosis. Herein, we report the case of a five-year-old boy who presented with intra-articular haemangioma and discuss the management of his condition.
  4. Kwan MK, Wong KA, Lee CK, Chan CY
    Eur Spine J, 2016 Feb;25(2):401-8.
    PMID: 25962815 DOI: 10.1007/s00586-015-4016-9
    PURPOSE: To introduce a new clinical neck tilt grading and to investigate clinically and radiologically whether neck tilt and shoulder imbalance is the same phenomenon in AIS patients.

    METHODS: 89 AIS Lenke 1 and 2 cases were assessed prospectively using the new clinical neck tilt grading. Shoulder imbalance and neck tilt were correlated with coracoid height difference (CHD), clavicle\rib intersection distance (CRID), clavicle angle (CA), radiographic shoulder height (RSH), T1 tilt and cervical axis.

    RESULTS: Mean age was 17.2 ± 3.8 years old. 66.3 % were Lenke type 1 and 33.7 % were type 2 curves. Strong intraobserver (0.79) and interobserver (0.75) agreement of the clinical neck tilt grading was noted. No significant correlation was observed between clinical neck tilt and shoulder imbalance (0.936). 56.3 % of grade 3 neck tilt, 50.0 % grade 2 neck tilt patients had grade 0 shoulder imbalance. In patients with grade 2 shoulder imbalance, 42.9 % had grade 0, 35.7 % grade 1, 14.3 % grade 2 and only 7.1 % had grade 3 neck tilt. CHD, CRID, CA and RSH correlated with shoulder imbalance. T1 tilt and cervical axis measurements correlated with neck tilt.

    CONCLUSIONS: In conclusion, neck tilt is distinct from shoulder imbalance. Clinical neck tilt has poor correlation with clinical shoulder imbalance. Clinical neck tilt grading correlated with cervical axis and T1 tilt whereas clinical shoulder grading correlated with CHD, RSH CRID and CA.

  5. Wong KP, Lee FCH, Teh PL, Chan AHS
    PMID: 33923234 DOI: 10.3390/ijerph18094525
    Today's workers are struggling to achieve a balance between their work and personal life roles because of both specific needs and limited resources. This study explored the socioecological factors that influence work-life balance (WLB) and how they operate. The relationships between WLB, subjective wellbeing, employee wellbeing and quality time allocation were examined. A total of 1063 responses were received, using an online survey. The results show that relational, community and societal factors directly influenced the individual factors and were indirectly associated with perceived WLB. Individual factors (i.e., personal feelings, behaviours and health) were found to be the crucial determinants of an individual's perceived WLB. It was found that WLB positively correlated with employee wellbeing and quality and quantity of personal life-time. Subjective wellbeing was found to be a significant moderator in the relationship between WLB and its outcomes. This study demonstrated the process of how workers determine their own WLB by applying the socioecological framework for categorising the determinants and suggested new avenues that improve the whole wellbeing of workers and also foster long-term development of organisations.
  6. Tang MC, Wong KH, Azman AS, Lani R
    Animal Model Exp Med, 2024 Jul 10.
    PMID: 38987937 DOI: 10.1002/ame2.12471
    Vector-borne diseases caused by arthropod-borne viruses (arboviruses) are a considerable challenge to public health globally. Mosquito-borne arboviruses, such as Chikungunya, Dengue, and Zika viruses, cause a range of human illnesses and may be fatal. Currently, efforts to control these diseases still face challenges due to growing vector resistance towards insecticides, urbanization, and limited effective antiviral treatments and vaccines. Animal models are crucial in antiviral research on mosquito-borne arboviruses, playing a role in understanding disease mechanisms, vaccine development, and toxicity testing, but the application of animal models still faces the challenges of ethical considerations and animal-to-human translational success. Genetically engineered mouse models, hamster models and non-human primate (NHP) are currently used in arbovirus research, but new models such as tree shrews and novel humanized mice are emerging. In the context of Malaysian research, the use of long-tailed macaques as potential NHP models for arbovirus research is possible; however, it faces the ethical dilemma of using an endangered species for scientific purposes. Overall, animal models play a crucial role in advancing infectious disease research, but a balance between medical research and species conservation must be upheld.
  7. Low ZY, Wong KH, Wen Yip AJ, Choo WS
    Curr Res Microb Sci, 2023;5:100202.
    PMID: 37700857 DOI: 10.1016/j.crmicr.2023.100202
    Influenza virus infection, more commonly known as the 'cold flu', is an etiological agent that gives rise to recurrent annual flu and many pandemics. Dated back to the 1918- Spanish Flu, the influenza infection has caused the loss of many human lives and significantly impacted the economy and daily lives. Influenza virus can be classified into four different genera: influenza A-D, with the former two, influenza A and B, relevant to humans. The capacity of antigenic drift and shift in Influenza A has given rise to many novel variants, rendering vaccines and antiviral therapies useless. In light of the emergence of a novel betacoronavirus, the SARS-CoV-2, unravelling the underpinning mechanisms that support the recurrent influenza epidemics and pandemics is essential. Given the symptom similarities between influenza and covid infection, it is crucial to reiterate what we know about the influenza infection. This review aims to describe the origin and evolution of influenza infection. Apart from that, the risk factors entail the implication of co-infections, especially regarding the COVID-19 pandemic is further discussed. In addition, antiviral strategies, including the potential of drug repositioning, are discussed in this context. The diagnostic approach is also critically discussed in an effort to understand better and prepare for upcoming variants and potential influenza pandemics in the future. Lastly, this review encapsulates the challenges in curbing the influenza spread and provides insights for future directions in influenza management.
  8. Beng TS, Ghee WK, Hui NY, Yin OC, Kelvin KWS, Yiling ST, et al.
    Palliat Support Care, 2021 Mar 15.
    PMID: 33715663 DOI: 10.1017/S1478951521000262
    OBJECTIVE: Dying is mostly seen as a dreadful event, never a happy experience. Yet, as palliative care physicians, we have seen so many patients who remained happy despite facing death. Hence, we conducted this qualitative study to explore happiness in palliative care patients at the University of Malaya Medical Centre.

    METHOD: Twenty terminally ill patients were interviewed with semi-structured questions. The results were thematically analyzed.

    RESULTS: Eight themes were generated: the meaning of happiness, connections, mindset, pleasure, health, faith, wealth, and work. Our results showed that happiness is possible at the end of life. Happiness can coexist with pain and suffering. Social connections were the most important element of happiness at the end of life. Wealth and work were given the least emphasis. From the descriptions of our patients, we recognized a tendency for the degree of importance to shift from the hedonic happiness to eudaimonic happiness as patients experienced a terminal illness.

    SIGNIFICANCE OF RESULTS: To increase the happiness of palliative care patients, it is crucial to assess the meaning of happiness for each patient and the degree of importance for each happiness domain to allow targeted interventions.

  9. Naftalin CM, Wong NS, Chan DP, Wong KH, Reidpath DD, Lee SS
    Int J STD AIDS, 2015 Oct;26(11):803-9.
    PMID: 25281539 DOI: 10.1177/0956462414553826
    To explore the heterogeneity of CD4 responses following highly active antiretroviral therapy, the patterns of CD4 recovery of HIV-1-infected Chinese patients who have been on their first antiretroviral regimen for ≥5 years were analysed. The CD4 trajectories were traced, smoothed and differentiated into three defined profiles. Half (56.3%) were 'satisfactory responders', with CD4 gain of >100 cells/μL and a peak of >350 cells/μL, plateauing before the end of Year 5. Thirty-three (24.4%) were 'continuing responders' whose CD4 rise persisted at Year 4-5. The remaining 26 (19.3%) were 'poor responders'. Presentation with AIDS before therapy was common not just among 'poor' but also paradoxically the 'continuing' responders. While a majority had responded well to antiretroviral therapy, older patients and those with AIDS diagnosis before initiation of therapy may never achieve a satisfactory level even with effective treatment. Categorization of HIV patients by their CD4 trajectory may support the prediction of immunological outcome over time, and ultimately inform treatment choices.
  10. Chan EWL, Yeo ETY, Wong KWL, See ML, Wong KY, Gan SY
    Curr Alzheimer Res, 2019;16(3):251-260.
    PMID: 30819080 DOI: 10.2174/1567205016666190228124630
    BACKGROUND: Alzheimer's disease (AD) is a multifactorial neurodegenerative disorder that eventually leads to severe cognitive impairment. Although the exact etiologies of AD still remain elusive, increasing evidence suggests that neuroinflammation cascades mediated by microglial cells are associated with AD. Piper sarmentosum Roxb. (PS) is a medicinal plant reported to possess various biological properties, including anti-inflammatory, anti-psychotic and anti-oxidant activity. However, little is known about the anti-inflammatory activity of PS roots despite their traditional use to treat inflammatory- mediated ailments.

    OBJECTIVE: This study aimed to evaluate the anti-inflammatory and neuroprotective properties of extracts obtained from the roots of PS against beta-amyloid (Aβ)-induced microglial toxicity associated with the production of pro-inflammatory mediators.

    METHOD: BV2 microglial cells were treated with hexane (RHXN), dichloromethane (RDCM), ethyl acetate (REA) and methanol (RMEOH) extracts of the roots of PS prior to activation by Aβ. The production and mRNA expression of pro-inflammatory mediators were evaluated by Griess reagent, ELISA kits and RT-qPCR respectively. The phosphorylation status of p38α MAPK was determined via western blot assay. BV2 conditioned medium was used to treat SH-SY5Y neuroblastoma cells and the neuroprotective effect was assessed using MTT assay.

    RESULTS: PS root extracts, in particular RMEOH significantly attenuated the production and mRNA expression of IL-1β, IL-6 and TNF-α in Aβ-induced BV2 microglial cells. In addition, RHXN, REA and RMEOH extracts significantly reduced nitric oxide (NO) level and the inhibition of NO production was correlated with the total phenolic content of the extracts. Further mechanistic studies suggested that PS root extracts attenuated the production of cytokines by regulating the phosphorylation of p38α MAPK in microglia. Importantly, PS root extracts have protective effects against Aβ-induced indirect neurotoxicity either by inhibiting the production of NO, IL-1β, IL-6, and TNF-α in BV2 cells or by protecting SHSY5Y cells against these inflammatory mediators.

    CONCLUSIONS: These findings provided evidence that PS root extracts confer neuroprotection against Aβ- induced microglial toxicity associated with the production of pro-inflammatory mediators and may be a potential therapeutic agent for inflammation-related neurological conditions including Alzheimer's disease (AD).

  11. Manshor NA, Wali Q, Wong KK, Muzakir SK, Fakharuddin A, Schmidt-Mende L, et al.
    Phys Chem Chem Phys, 2016 Aug 21;18(31):21629-39.
    PMID: 27432518 DOI: 10.1039/c6cp03600g
    Despite the high efficiency of over 21% reported for emerging thin film perovskite solar cells, one of the key issues prior to their commercial deployment is to attain their long term stability under ambient and outdoor conditions. The instability in perovskite is widely conceived to be humidity induced due to the water solubility of its initial precursors, which leads to decomposition of the perovskite crystal structure; however, we note that humidity alone is not the major degradation factor and it is rather the photon dose in combination with humidity exposure that triggers the instability. In our experiment, which is designed to decouple the effect of humidity and light on perovskite degradation, we investigate the shelf-lifetime of CH3NH3PbI3 films in the dark and under illumination under high humidity conditions (Rel. H. > 70%). We note minor degradation in perovskite films stored in a humid dark environment whereas upon exposure to light, the films undergo drastic degradation, primarily owing to the reactive TiO2/perovskite interface and also the surface defects of TiO2. To enhance its air-stability, we incorporate CH3NH3PbI3 perovskite in a polymer (poly-vinylpyrrolidone, PVP) matrix which retained its optical and structural characteristics in the dark for ∼2000 h and ∼800 h in room light soaking, significantly higher than a pristine perovskite film, which degraded completely in 600 h in the dark and in less than 100 h when exposed to light. We attribute the superior stability of PVP incorporated perovskite films to the improved structural stability of CH3NH3PbI3 and also to the improved TiO2/perovskite interface upon incorporating a polymer matrix. Charge injection from the polymer embedded perovskite films has also been confirmed by fabricating solar cells using them, thereby providing a promising future research pathway for stable and efficient perovskite solar cells.
  12. Wong KW, Ee GCL, Ismail IS, Karunakaran T, Jong VYM
    Nat Prod Res, 2017 Nov;31(21):2513-2519.
    PMID: 28412841 DOI: 10.1080/14786419.2017.1315717
    Phytochemical studies on the stem bark of Garcinia nervosa has resulted in the discovery of one new pyranoxanthone derivative, garner xanthone (1) and five other compounds, 1,5-dihydroxyxanthone (2), 6-deoxyisojacareubin (3), 12b-hydroxy-des-D-garcigerrin A (4) stigmasterol (5), and β-sitosterol (6). The structures of these compounds were elucidated with the aid of spectroscopic techniques, such as NMR and MS. The crude extracts of the plant were assessed for their antimicrobial activity.
  13. Yeo ETY, Wong KWL, See ML, Wong KY, Gan SY, Chan EWL
    J Ethnopharmacol, 2018 May 10;217:187-194.
    PMID: 29462698 DOI: 10.1016/j.jep.2018.02.025
    ETHNOPHARMACOLOGICAL RELEVANCE: Piper sarmentosum Roxb. (PS), belonging to Piperaceae family, is an edible plant with medicinal properties. It is traditionally used by the Malays to treat headache and boost memory. Pharmacological studies revealed that PS exhibits anti-inflammatory, anti-oxidant, anti-acetylcholinesterase, and anti-depressant-like effects. In view of this, the present study aimed to investigate the anti-inflammatory actions of PS and its potential neuroprotective effects against beta-amyloid (Aβ)-induced microglia-mediated neurotoxicity.

    MATERIALS AND METHODS: The inhibitory effects of hexane (LHXN), dichloromethane (LDCM), ethyl acetate (LEA) and methanol (LMEOH) extracts from leaves of PS on Aβ-induced production and mRNA expression of pro-inflammatory mediators in BV-2 microglial cells were assessed using colorimetric assay with Griess reagent, ELISA kit and real-time RT-PCR respectively. Subsequently, MTT reduction assay was used to evaluate the neuroprotective effects of PS leaf extracts against Aβ-induced microglia-mediated neurotoxicity in SH-SY5Y neuroblastoma cells. The levels of tau proteins phosphorylated at threonine 231 (pT231) and total tau proteins (T-tau) were determined using ELISA kits.

    RESULTS: Polar extracts of PS leaves (LEA and LMEOH) reduced the Aβ-induced secretion of pro-inflammatory cytokines (IL-1β and TNF-α) in BV-2 cells by downregulating the mRNA expressions of pro-inflammatory cytokines. The inhibition of nitric oxide (NO) production could be due to the free radical scavenging activity of the extracts. In addition, conditioned media from Aβ-induced BV-2 cells pre-treated with LEA and LMEOH protected SH-SY5Y cells against microglia-mediated neurotoxicity. Further mechanistic study suggested that the neuroprotective effects were associated with the downregulation of phosphorylated tau proteins.

    CONCLUSIONS: The present study suggests that polar extracts of PS leaves confer neuroprotection against Aβ-induced microglia-mediated neurotoxicity in SH-SY5Y cells by attenuating tau hyperphosphorylation through their anti-inflammatory actions and could be a potential therapeutic agent for Alzheimer's disease.

  14. Wong KW, Teh SS, Law KP, Ismail IS, Sato K, Mase N, et al.
    Arch Pharm (Weinheim), 2023 Jan;356(1):e2200418.
    PMID: 36285691 DOI: 10.1002/ardp.202200418
    Oxidative stress and its constant companion, inflammation, play a critical part in the pathogenesis of many acute and chronic illnesses. The discovery of new multi-targeted drug candidates with antioxidant and anti-inflammatory properties is deemed necessary. Thus, a series of novel xanthone derivatives with halogenated benzyl (4b-4d, 4f-4h) and methoxylated benzyl groups (4e) attached to the butoxy amine substituent were synthesized in this study. The synthesized xanthone derivatives exhibited stronger antioxidant activity against H2 O2 scavenging than the standard drug, α-tocopherol, but weaker towards DPPH scavenging and ferrous ion chelation. Besides that, 4b-4d, 4f-4h demonstrated good anti-inflammatory activities through NO production inhibition towards lipopolysaccharide (LPS)-induced RAW 264.7 cells and showed 2-4 times stronger effects than the standard drug, diclofenac sodium. Moreover, compound 4b with two brominated benzyl groups attached to the butoxy amine substituent suppressed the production of pro-inflammatory cytokines, TNF-α and IL-1β, significantly. Structure-activity relationship elucidated that the halogenated benzylamine substituent plays an important role in contributing the antioxidant and anti-inflammatory activities of xanthones. In summary, xanthone 4b was identified as a potential lead compound to be further developed into antioxidant and anti-inflammatory drugs. Thus, further studies on the related mechanisms of action of 4b are recommended.
  15. Wong KF, Lam XY, Jiang Y, Yeung AWK, Lin Y
    Head Face Med, 2023 Aug 23;19(1):38.
    PMID: 37612673 DOI: 10.1186/s13005-023-00383-0
    BACKGROUND: The application of artificial intelligence (AI) in orthodontics and orthognathic surgery has gained significant attention in recent years. However, there is a lack of bibliometric reports that analyze the academic literature in this field to identify publishing and citation trends. By conducting an analysis of the top 100 most-cited articles on AI in orthodontics and orthognathic surgery, we aim to unveil popular research topics, key authors, institutions, countries, and journals in this area.

    METHODS: A comprehensive search was conducted in the Web of Science (WOS) electronic database to identify the top 100 most-cited articles on AI in orthodontics and orthognathic surgery. Publication and citation data were obtained and further analyzed and visualized using R Biblioshiny. The key domains of the 100 articles were also identified.

    RESULTS: The top 100 most-cited articles were published between 2005 and 2022, contributed by 458 authors, with an average citation count of 22.09. South Korea emerged as the leading contributor with the highest number of publications (28) and citations (595), followed by China (16, 373), and the United States (7, 248). Notably, six South Korean authors ranked among the top 10 contributors, and three South Korean institutions were listed as the most productive. International collaborations were predominantly observed between the United States, China, and South Korea. The main domains of the articles focused on automated imaging assessment (42%), aiding diagnosis and treatment planning (34%), and the assessment of growth and development (10%). Besides, a positive correlation was observed between the testing sample size and citation counts (P = 0.010), as well as between the time of publication and citation counts (P 

  16. Andrew A, Citartan M, Wong KA, Tang TH, Magdline Sia Henry S, Ch'ng ES
    Microbiol Spectr, 2023 Aug 17;11(4):e0008823.
    PMID: 37272795 DOI: 10.1128/spectrum.00088-23
    Due to the general symptoms presented by the Chikungunya virus (CHIKV)-infected patients, a laboratory test is needed to differentiate CHIKV from other viral infections. The reverse transcription-quantitative real-time PCR (RT-qPCR) is a rapid and sensitive diagnostic tool, and several assays have been developed for detecting and quantifying CHIKV. Since real-time amplification efficiency varies within and between laboratories, an assay must be validated before being used on patient samples. In this study, the diagnostic performance of a TaqMan RT-qPCR assay was evaluated using synthetic RNA and archived patient samples. The cutoff quantification cycle (Cq) value for the assay was determined by experimental evidence. We found the in-house assay was highly sensitive, with a detection limit of 3.95 RNA copies/reaction. The analytical specificity of the assay was 100%. The analytical cutoff Cq value was 37, corresponding to the mean Cq value of the detection limit. Using archived samples characterized previously, the sensitivity and specificity of the assay were 76% and 100%, respectively. The in-house assay was also compared with a commercial assay, and we found that the in-house assay had higher sensitivity. Although further evaluation with prospective patient samples is needed in the future, this validated RT-qPCR was sensitive and specific, which shows its potential to detect CHIKV in clinical samples. IMPORTANCE Chikungunya virus causes chikungunya fever, a disease characterized by fever, rash, and joint pain. In the early phase of infection, chikungunya fever is always misdiagnosed as other arbovirus infections, such as dengue. Laboratory tests such as RT-qPCR are therefore necessary to confirm CHIKV infection. We evaluated the performance of an in-house RT-qPCR assay, and our study shows that the assay could detect CHIKV in clinical samples. We also show the cutoff determination of the assay, which provides important guidance to scientists or researchers when implementing a new RT-qPCR assay in a laboratory.
  17. Tan KH, Cham HY, Awala H, Ling TC, Mukti RR, Wong KL, et al.
    Nanoscale Res Lett, 2015 Dec;10(1):956.
    PMID: 26058517 DOI: 10.1186/s11671-015-0956-6
    Lubricant oils take significant part in current health and environmental considerations since they are an integral and indispensable component of modern technology. Antioxidants are probably the most important additives used in oils because oxidative deterioration plays a major role in oil degradation. Zeolite nanoparticles (NPs) have been proven as another option as green antioxidants in oil formulation. The anti-oxidative behavior of zeolite NPs is obvious; however, the phenomenon is still under investigation. Herein, a study of the effect of extra-framework cations stabilized on Linde Type L (LTL) zeolite NPs (ca. 20 nm) on inhibition of oxidation in palm oil-based lubricant oil is reported. Hydrophilic LTL zeolites with a Si/Al ratio of 3.2 containing four different inorganic cations (Li(+), Na(+), K(+), Ca(2+)) were applied. The oxidation of the lubricant oil was followed by visual observation, colorimetry, fourier transform infrared (FTIR) spectroscopy, (1)H NMR spectroscopy, total acid number (TAN), and rheology analyses. The effect of extra-framework cations to slow down the rate of oil oxidation and to control the viscosity of oil is demonstrated. The degradation rate of the lubricant oil samples is decreased considerably as the polarizability of cation is increased with the presence of zeolite NPs. More importantly, the microporous zeolite NPs have a great influence in halting the steps that lead to the polymerization of the oils and thus increasing the lifetime of oils.
  18. Malik RA, Andag-Silva A, Dejthevaporn C, Hakim M, Koh JS, Pinzon R, et al.
    J Diabetes Investig, 2020 Sep;11(5):1097-1103.
    PMID: 32268012 DOI: 10.1111/jdi.13269
    Burning and stabbing pain in the feet and lower limbs can have a significant impact on the activities of daily living, including walking, climbing stairs and sleeping. Peripheral neuropathy in particular is often misdiagnosed or underdiagnosed because of a lack of awareness amongst both patients and physicians. Furthermore, crude screening tools, such as the 10-g monofilament, only detect advanced neuropathy and a normal test will lead to false reassurance of those with small fiber mediated painful neuropathy. The underestimation of peripheral neuropathy is highly prevalent in the South-East Asia region due to a lack of consensus guidance on routine screening and diagnostic pathways. Although neuropathy as a result of diabetes is the most common cause in the region, other causes due to infections (human immunodeficiency virus, hepatitis B or C virus), chronic inflammatory demyelinating polyneuropathy, drug-induced neuropathy (cancer chemotherapy, antiretrovirals and antituberculous drugs) and vitamin deficiencies (vitamin B1 , B6 , B12 , D) should be actively excluded.
  19. Chan EWL, Yeo ETY, Wong KWL, See ML, Wong KY, Yap JKY, et al.
    Curr Alzheimer Res, 2021;18(1):80-87.
    PMID: 33761853 DOI: 10.2174/1567205018666210324124239
    BACKGROUND: In Alzheimer's disease, accumulation of beta amyloid (Aβ) triggers amyloidogenesis and hyperphosphorylation of tau protein leading to neuronal cell death. Piper sarmentosum Roxb. (PS) is a traditional medicinal herb used by Malay to treat rheumatism, headache and boost memory. It possesses various biological effects, such as anti-cholinergic, anti-inflammatory, anti-oxidant and anti-depressant-like effects.

    OBJECTIVE: The present study aimed to investigate neuroprotective properties of PS against Aβ-induced neurotoxicity and to evaluate its potential mechanism of action.

    METHODS: Neuroprotective effects of hexane (HXN), dichloromethane (DCM), ethyl acetate (EA) and methanol (MEOH) extracts from leaves (L) and roots (R) of PS against Aβ-induced neurotoxicity were investigated in SH-SY5Y human neuroblastoma cells. Cells were pre-treated with PS for 24 h followed by 24 h of induction with Aβ. The neuroprotective effects of PS were studied using cell viability and cellular reactive oxygen species (ROS) assays. The levels of extracellular Aβ and tau proteins phosphorylated at threonine 231 (pT231) were determined. Gene and protein expressions were assessed using qRT-PCR analyses and western blot analyses, respectively.

    RESULTS: Hexane extracts of PS (LHXN and RHXN) protected SH-SY5Y cells against Aβ-induced neurotoxicity, and decreased levels of extracellular Aβ and phosphorylated tau (pT231). Although extracts of PS inhibited Aβ-induced ROS production, it was unlikely that neuroprotective effects were simply due to the anti-oxidant capacity of PS. Further, mechanistic study suggested that the neuroprotective effects of PS might be due to its capability to regulate amyloidogenesis through the downregulation of BACE and APP.

    CONCLUSION: These findings suggest that hexane extracts of PS confer neuroprotection against Aβ- induced neurotoxicity in SH-SY5Y cells by attenuating amyloidogenesis and tau hyperphosphorylation. Due to its neuroprotective properties, PS might be a potential therapeutic agent for Alzheimer's disease.

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