Displaying publications 81 - 100 of 162 in total

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  1. Kong YR, Jong YX, Balakrishnan M, Bok ZK, Weng JKK, Tay KC, et al.
    Biology (Basel), 2021 Apr 01;10(4).
    PMID: 33916114 DOI: 10.3390/biology10040287
    Oxidative stress is a result of disruption in the balance between antioxidants and pro-oxidants in which subsequently impacting on redox signaling, causing cell and tissue damages. It leads to a range of medical conditions including inflammation, skin aging, impaired wound healing, chronic diseases and cancers but these conditions can be managed properly with the aid of antioxidants. This review features various studies to provide an overview on how Carica papaya help counteract oxidative stress via various mechanisms of action closely related to its antioxidant properties and eventually improving the management of various oxidative stress-related health conditions. Carica papaya is a topical plant species discovered to contain high amounts of natural antioxidants that can usually be found in their leaves, fruits and seeds. It contains various chemical compounds demonstrate significant antioxidant properties including caffeic acid, myricetin, rutin, quercetin, α-tocopherol, papain, benzyl isothiocyanate (BiTC), and kaempferol. Therefore, it can counteract pro-oxidants via a number of signaling pathways that either promote the expression of antioxidant enzymes or reduce ROS production. These signaling pathways activate the antioxidant defense mechanisms that protect the body against both intrinsic and extrinsic oxidative stress. To conclude, Carica papaya can be incorporated into medications or supplements to help manage the health conditions driven by oxidative stress and further studies are needed to investigate the potential of its chemical components to manage various chronic diseases.
  2. Rehman IU, Wu DB, Ahmed R, Khan NA, Rahman AU, Munib S, et al.
    Medicine (Baltimore), 2018 08;97(31):e10764.
    PMID: 30075491 DOI: 10.1097/MD.0000000000010764
    BACKGROUND: Pruritus adds to the complications of chronic kidney disease (CKD) patient and a well-recognized complication among the CKD patients. Majority of the patients on hemodialysis experience a generalized pruritus and patients reported being moderately to extremely disturbed by at least one of the sleep-related condition. This study aim to investigate the effectiveness of zolpidem 10 mg and acupressure therapy on foot acupoints to improve the sleep quality and overall quality of life among hemodialysis patients suffering from CKD-associated pruritus.

    METHODS: A multicentered, open-label, parallel group, prospective randomized controlled trial among patients suffering from CKD-associated pruritus with sleep disturbance, after randomization into control, and intervention group to be held at North West General Hospital and Research Center Peshawar, Pakistan and Institute of Kidney Diseases Peshawar, Pakistan.

    RESULTS: The primary outcome is to investigate the effectiveness of zolpidem 10 mg and acupressure therapy on foot acupoints to improve the sleep quality and overall quality of life among hemodialysis patients suffering from CKD-associated pruritus. After baseline assessment by Urdu version of 5D itch scale and Urdu version of Pittsburgh Sleep Quality Index (PSQI) and Urdu EQ-5D 3L, the intervention group will be given zolpidem 10 mg oral tablets and control group with acupressure on both foots on KI-1 acupoints for total of 6 minutes. Assessment will be done at weeks 4 and 8 from baseline by using Urdu version of 5D itch scale and Urdu version of PSQI and Urdu EQ-5D 3L, whereas safety profiling of zolpidem 10 mg tablet at week 6 from baseline and acupressure acceptability at week 6 from baseline. Analysis of covariance will be used to examine the differences in treatment effects between the intervention and control groups.

    CONCLUSION: Improvement of sleep quality and quality of life among patients with CKD-associated pruritus requires great importance. This study aims to improve the quality of sleep and quality of life among patients with hemodialysis suffering from CKD-associated pruritus.

  3. Rehman IU, Chan KG, Munib S, Lee LH, Khan TM
    Medicine (Baltimore), 2019 Sep;98(36):e16812.
    PMID: 31490367 DOI: 10.1097/MD.0000000000016812
    Chronic kidney disease (CKD)-associated pruritus is one of the most common symptoms found in patients who undergo dialysis for CKD, leading to a compromised quality of life. This study aimed to investigate the association between CKD-associated pruritus and the quality of life in patients undergoing hemodialysis in Pakistan.A cross-sectional multicenter study was carried out from July 2016 to April 2017 in 2 tertiary care hospitals in Pakistan. Patients aged 18 years and above of both genders, undergoing hemodialysis, understood the Urdu language, and were willing to participate; were included.Of 354 recruited patients with a response rate of 100%, majority (66.1%) of the patients were males. The median (intra-quartile range [IQR]) age of patients was 42.0 [34.0-50.0] years. The prevalence of pruritus was 74%. The median [IQR] score for pruritus was 10.0 (out of possible 25) [8.0-12.0]. Multivariate linear regression revealed a statistically significant association between CKD-associated pruritus with age of patients (β = 0.031; 95% confidence interval [CI] = 0.002-0.061; P = .038), duration of CKD (β = -0.013; 95% CI = -0.023 --0.003; P = .014) and quality of life (β= -0.949; 95% CI = -1.450; -0.449). The median [IQR] score for health-related quality of life was 52.00 [43.00-58.00].Prevalence of CKD-associated pruritus was reported to be 74% and it negatively affected the patient's quality of life. Patients with moderate to severe CKD-associated pruritus have poor quality of life. With an increase in intensity of pruritus, the QOL score decreased among the patients undergoing hemodialysis.
  4. Bukhsh A, Tan XY, Chan KG, Lee LH, Goh BH, Khan TM
    Patient Prefer Adherence, 2018;12:2457-2474.
    PMID: 30538430 DOI: 10.2147/PPA.S180256
    Background: Effectiveness of pharmacist-led educational interventions on self-care activities and glycemic control of type 2 diabetes mellitus (T2DM) patients is vague. The purpose of this review is to appraise the effect of pharmacist-led educational interventions on self-care activities and levels of glycated hemoglobin of T2DM patients.

    Methods: Five electronic databases were searched from date of database inception to September 2017. Randomized clinical trials examining the effectiveness of pharmacist-led educational interventions, directed at T2DM patients only, were included for systematic review and meta-analysis. The protocol is available with PROSPERO (CRD42017078854).

    Results: Eleven studies, involving n=1,544 T2DM patients, were included in this systematic review. Meta-analysis demonstrated that pharmacist-led interventions had a significant effect on lowering of the levels of glycated hemoglobin (-0.66; 95% CI [-0.83, -0.50]; I2=58.3%; P=0.008), in comparison to usual care. Self-care activities were assessed by using Summary of Diabetes Self-care Activities tool in eight studies. Overall meta-analysis of self-care activities for included studies demonstrated a significant effect of pharmacist-led interventions on improvement of self-monitoring of blood glucose (1.62; 95% CI [0.92, 2.32]; I2=70.5%; P=0.005), foot care (1.20; 95% CI [0.49, 1.90]; I2=95.0%; P<0.001), and overall diet (1.16; 95% CI [0.38, 1.93]; I2=64.2%; P=0.094).

    Conclusion: The findings of this review demonstrate a significantly positive effect of pharmacist-led educational interventions on HbA1c levels and self-care practices among T2DM patients.
  5. Yong YL, Tan LT, Ming LC, Chan KG, Lee LH, Goh BH, et al.
    Front Pharmacol, 2016;7:538.
    PMID: 28119613 DOI: 10.3389/fphar.2016.00538
    In particular, neuropathic pain is a major form of chronic pain. This type of pain results from dysfunction or lesions in the central and peripheral nervous system. Capsaicin has been traditionally utilized as a medicine to remedy pain. However, the effectiveness and safety of this practice is still elusive. Therefore, this systematic review aimed to investigate the effect of topical capsaicin as a pain-relieving agent that is frequently used in pain management. In brief, all the double-blinded, randomized placebo- or vehicle-controlled trials that were published in English addressing postherpetic neuralgia were included. Meta-analysis was performed using Revman(®) version 5.3. Upon application of the inclusion and exclusion criteria, only six trials fulfilled all the criteria and were included in the review for qualitative analysis. The difference in mean percentage change in numeric pain rating scale score ranges from -31 to -4.3. This demonstrated high efficacy of topical capsaicin application and implies that capsaicin could result in pain reduction. Furthermore, meta-analysis was performed on five of the included studies. All the results of studies are in favor of the treatment using capsaicin. The incidence of side effects from using topical capsaicin is consistently higher in all included studies, but the significance of safety data cannot be quantified due to a lack of p-values in the original studies. Nevertheless, topical capsaicin is a promising treatment option for specific patient groups or certain neuropathic pain conditions such as postherpetic neuralgia.
  6. Rahman FA, Abdullah SS, Manan WZWA, Tan LT, Neoh CF, Ming LC, et al.
    Front Pharmacol, 2018;9:238.
    PMID: 29970999 DOI: 10.3389/fphar.2018.00238
    There are various studies that have addressed the use of Cyclosporine among patients with acute myocardial infarction (AMI). However, to date there is hardly any concise and systematically structured evidence that debate on the efficacy and safety of Cyclosporine in AMI patients. The aim of this review is to systematically summarize the overall evidence from published trials, and to conduct a meta-analysis in order to determine the efficacy and safety of Cyclosporine vs. placebo or control among patients with AMI. All randomized control trial (RCT) published in English language from January 2000 to August 2017 were included for the systematic review and meta-analysis. A total of six RCTs met the inclusion and were hence included in the systematic review and meta-analysis. Based on the performed meta-analysis, no significant difference was found between Cyclosporine and placebo in terms of left ventricular ejection fraction (LVEF) improvement (mean difference 1.88; 95% CI -0.99 to 4.74; P = 0.2), mortality rate (OR 1.01; 95% Cl 0.60 to 1.67, P = 0.98) and recurrent MI occurrence (OR 0.65; 95% Cl 0.29 to 1.45, P = 0.29), with no evidence of heterogeneity, when given to patients with AMI. Cyclosporine also did not significantly lessen the rate of rehospitalisation in AMI patients when compared to placebo (OR 0.91; 95% Cl 0.58 to 1.42, P = 0.68), with moderate heterogeneity (I2 = 46%). There was also no significant improvement in heart failure events between Cyclosporine and placebo in AMI patients (OR 0.63; 95% Cl 0.31 to 1.29, P = 0.21; I2 = 80%). No serious adverse events were reported in Cyclosporine group across all studies suggesting that Cyclosporine is well tolerated when given to patients with AMI. The use of Cyclosporine in this group of patients, however, did not result in better clinical outcomes vs. placebo at improving LVEF, mortality rate, recurrent MI, rehospitalisation and heart failure event.
  7. Rehman IU, Lai PSM, Lim SK, Lee LH, Khan TM
    BMC Nephrol, 2019 03 25;20(1):102.
    PMID: 30909887 DOI: 10.1186/s12882-019-1294-1
    BACKGROUND: Chronic kidney disease-associated pruritus (CKD-aP) is a well-recognized, frequent and compromising complication among patients on hemodialysis. Despite advancement in basic medical sciences, CKD-aP is still a major complication and a challenge for both physicians and patients to manage. The aim of this study was to estimate the prevalence of CKD-aP among hemodialysis patients in Malaysia, to determine the impact of CKD-aP on sleep quality and any factors associated with CKD-aP.

    METHOD: A multi-centered, cross-sectional study design was conducted from February 2017 to September 2017 at a tertiary hospital and its affiliated dialysis centers, in Kuala Lumpur, Malaysia. Included were patients > 18 years of age who were undergoing hemodialysis and could understand Malay. Participants were asked to fill the Malay 5D-itch scale and the Malay Pittsburgh sleep quality index (PSQI) upon recruitment.

    RESULTS: A total of 334/334 patients were recruited (response rate = 100%). The majority were male (59.6%) and Chinese (61.7%). A total of 61.3% had pruritus, of which most patients (63.4%) reported that their pruritus was mild. More than half (54.1%) reported that they slept > 6 h, and 93.2% experienced no sleep disturbances during the night. However; the overall PSQI median score [IQR] was 6.0 [5.0-9.0]. No significant association was found between demographic and clinical characteristics of patients with the severity of pruritus. Patients with moderate to severe pruritus were found to be 5.47 times more likely to experience poor sleep quality as compared to patients with mild or no pruritus.

    CONCLUSION: In Malaysia, the prevalence of CKD-aP was 61.3%, of which the majority reported that their pruritus was mild. Patients with moderate to severe pruritus were found to be 5.47 times more likely to experience poor sleep quality as compared to patients with mild or no pruritus.

  8. Rehman IU, Lai PS, Kun LS, Lee LH, Chan KG, Khan TM
    Ther Apher Dial, 2020 Feb;24(1):17-25.
    PMID: 31152625 DOI: 10.1111/1744-9987.12862
    CKD-associated pruritus is one of the common symptoms in patients undergoing dialysis, thus contributing to the diminished and compromised quality of life. This study aimed to explore the association between the CKD-associated pruritus on quality of life of patients undergoing hemodialysis in Malaysia. A cross-sectional multicenter study, carried out from February to September 2017 at tertiary care settings in Kuala Lumpur, Malaysia. Patients aged 18 years and above, undergoing hemodialysis, understanding Malay language and willing to participate were included. The CKD-associated pruritus was assessed by using Malay 5D-itch scale and Malay FANLTC questionaiare. To determine the factors associated with pruritus and quality of life, multivariate logistic regression analysis was used having P value < 0.05 as statistically significant. Among n = 334 recruited patients with a response rate of 100%, 59.6% were males and total of 61.3% were having CKD-associated pruritus. The results showed a statistically significant weak negative correlation between CKD-associated pruritus and quality of life. Multivariate linear regression revealed none of these factors were found to be associated with pruritus; however, CKD-associated prurtius was found to be associated with quality of life score. CKD-associated pruritus is have a negative impact on the patient's quality of life including physical, social, mental/emotional, and functional well-being. Despite the high prevalence and negative impact of CKD-associated pruritus on quality of life, it is disregarded by most health care professionals. It is thus pertinent to monitor the potential risk factors and consider providing timely treatment implications for CKD-associated pruritus in hemodialysis patients, in order to improve their quality of life.
  9. Bukhsh A, Rehman H, Mallhi TH, Ata H, Rehman IU, Lee LH, et al.
    Hum Vaccin Immunother, 2018 04 03;14(4):952-957.
    PMID: 29333939 DOI: 10.1080/21645515.2017.1415686
    National immunization program of Pakistan does not include Influenza vaccines. The low rate of immunization might be attributed to the poor knowledge of influenza vaccination in Pakistan. Current study was aimed to assess the knowledge and attitude of influenza vaccination among parents. A questionnaire-based cross sectional study was conducted among randomly selected parents with at least one child aged >6 months. The responses were recorded against 27 items questionnaire assessing knowledge, perception, attitude and behaviours of parents. Data were analysed by using appropriate statistical methods. A total 532 responses were recorded with male gender preponderance (65%). Most of the parents (61.1%) reported that their children had received or planned to receive all recommended vaccines in Expanded Program on Immunization (EPI) of Pakistan. Only one third of the parents (24.4%) were aware of the availability of influenza vaccines in Pakistan, and very few (6.6%) reported vaccinating their child against influenza. Exploring the parents' attitudes regarding children vaccination, the top motivator was 'immunization is important to keep my children healthy' (relative index = 0.93, p < 0.000). However, substantial number of parents believed that influenza is not a serious disease (18.5%) and vaccines are accompanied by several side effects (24.6%). A positive attitude was reflected among parents who were aware of influenza vaccines in Pakistan. About 35% participants believed that influenza vaccines are not required for healthy children. Current study demonstrated very low vaccination rate against influenza. Awareness and health literacy regarding influenza vaccine is poor among parents. These findings necessitate the need to appropriately structured awareness programs regarding influenza vaccination among parents.
  10. Rehman IU, Ahmed R, Rahman AU, Wu DBC, Munib S, Shah Y, et al.
    Medicine (Baltimore), 2021 May 28;100(21):e25995.
    PMID: 34032717 DOI: 10.1097/MD.0000000000025995
    BACKGROUND: Chronic kidney disease (CKD)-associated pruritus (CKD-aP) contributes to poor quality of life, including reduced sleep quality and poor sleep quality is a source of patient stress and is linked to lower health-related quality of life. This study aimed to investigate the effectiveness of zolpidem 10 mg and acupressure therapy on foot acupoints to improve the sleep quality and overall quality of life among hemodialysis patients suffering from CKD-aP.

    METHOD: A multicenter, prospective, randomized, parallel-design, open label interventional study to estimate the effectiveness of zolpidem (10 mg) oral tablets versus acupressure on sleep quality and quality of life in patients with CKD-aP on hemodialysis. A total of 58 hemodialysis patients having sleep disturbance due to CKD-aP completed the entire 8-week follow-up. The patients were divided into a control (acupressure) group of 28 patients and an intervention (zolpidem) group of 30 patients.

    RESULTS: A total of 58 patients having CKD-aP and sleep disturbance were recruited. In the control group there was a reduction in the PSQI score with a mean ± SD from 12.28 ± 3.59 to 9.25 ± 3.99, while in the intervention group the reduction in PSQI score with a mean ± SD was from 14.73 ± 4.14 to 10.03 ± 4.04 from baseline to endpoint. However, the EQ5D index score and EQ-visual analogue scale (VAS) at baseline for the control group with a mean ± SD was 0.49 ± 0.30 and 50.17 ± 8.65, respectively, while for the intervention group the values were 0.62 ± 0.26 and 47.17 ± 5.82, respectively. The mean EQ5D index score in the control group improved from 0.49 ± 0.30 to 0.53 ± 0.30, but in the intervention group there was no statistical improvement in mean EQ5D index score from 0.62 ± 0.26 to 0.62 ± 0.27 from baseline to week 8. The EQ 5D improved in both groups and the EQ-VAS score was 2.67 points higher at week 8 as compared to baseline in the control group, while in the intervention group the score was 3.33 points higher at week 8 as compared to baseline. Comparing with baseline, the PSQI scores were significantly reduced after week 4 and week 8 (P =  

  11. Lee LH, Cheah YK, Sidik SM, Xie QY, Tang YL, Lin HP, et al.
    Int J Syst Evol Microbiol, 2013 Jan;63(Pt 1):241-248.
    PMID: 22389286 DOI: 10.1099/ijs.0.038232-0
    Three novel actinobacteria, strains 39(T), 40 and 41, were isolated from soil collected from Barrientos Island in the Antarctic. The taxonomic status of these strains was determined using a polyphasic approach. Comparison of 16S rRNA gene sequences revealed that strain 39(T) represented a novel lineage within the family Dermacoccaceae and was most closely related to members of the genera Demetria (96.9 % 16S rRNA gene sequence similarity), Branchiibius (95.7 %), Dermacoccus (94.4-95.3 %), Calidifontibacter (94.6 %), Luteipulveratus (94.3 %), Yimella (94.2 %) and Kytococcus (93.1 %). Cells were irregular cocci and short rods. The peptidoglycan type was A4α with an L-Lys-L-Ser-D-Asp interpeptide bridge. The cell-wall sugars were galactose and glucose. The major menaquinone was MK-8(H(4)). The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphoglycolipid, two glycolipids and one unknown phospholipid. The acyl type of the cell-wall polysaccharide was N-acetyl. The major cellular fatty acids were anteiso-C(17 : 0) (41.97 %), anteiso-C(17 : 1)ω9c (32.16 %) and iso-C(16 : 0) (7.68 %). The DNA G+C content of strain 39(T) was 68.4 mol%. On the basis of phylogenetic and phenotypic differences from other genera of the family Dermacoccaceae, a novel genus and species, Barrientosiimonas humi gen. nov., sp. nov., is proposed; the type strain of the type species is 39(T) (=CGMCC 4.6864(T) = DSM 24617(T)).
  12. Lee LH, Cheah YK, Mohd Sidik S, Ab Mutalib NS, Tang YL, Lin HP, et al.
    World J Microbiol Biotechnol, 2012 May;28(5):2125-37.
    PMID: 22806035 DOI: 10.1007/s11274-012-1018-1
    The present study aimed to isolate actinobacteria from soil samples and characterized them using molecular tools and screened their secondary metabolites for antimicrobial activities. Thirty-nine strains from four different location of Barrientos Island, Antarctica using 12 types of isolation media was isolated. The isolates were preceded to screening of secondary metabolites for antimicrobial and antifungal activities. Using high-throughput screening methods, 38% (15/39) of isolates produced bioactive metabolites. Approximately 18% (7/39), 18% (7/39), 10% (4/39) and 2.5% (1/39) of isolates inhibited growth of Candida albicans ATCC 10231(T), Staphylococcus aurues ATCC 51650(T), methicillin-resistant Staphylococcus aurues (MRSA) ATCC BAA-44(T) and Pseudomonas aeruginosa ATCC 10145(T), respectively. Molecular characterization techniques like 16S rRNA analysis, Enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR), Random amplified polymorphic DNA (RAPD) and composite analyses were used to characterize the actinobacteria strains. Analysis of 16S rRNA sequences is still one of the most powerful methods to determine higher taxonomic relationships of Actinobacteria. Both RAPD and ERIC-PCR fingerprinting have shown good discriminatory capability but RAPD proved to be better in discriminatory power than ERIC-PCR. Our results demonstrated that composite analysis of both fingerprinting generally increased the discrimination ability and generated best clustering for actinobacteria strains in this study.
  13. Lee LH, Cheah YK, Nurul Syakima AM, Shiran MS, Tang YL, Lin HP, et al.
    Genet. Mol. Res., 2012;11(2):1627-41.
    PMID: 22782582 DOI: 10.4238/2012.June.15.12
    Fifty-seven proteobacterium species were successfully isolated from soils of Barrientos Island of the Antarctic using 11 different isolation media. Analysis of 16S rDNA sequencing of these isolates showed that they belonged to eight different genera, namely Bradyrhizobium, Sphingomonas, Methylobacterium, Caulobacter, Paracoccus, Ralstonia, Rhizobium, and Staphylococcus. All isolates were studied for capability of producing antimicrobial and antifungal secondary metabolites using high-throughput screening models. Approximately 23 (13/57) and 2% (1/57) of isolates inhibited growth of Candida albicans ATCC 10231(T) and Staphylococcus aureus ATCC 51650(T), respectively. These results indicated that proteobacterium species isolates from Antarctic could serve as potential source of useful bioactive metabolites. Enterobacterial repetitive intergenic consensus (ERIC)-PCR fingerprinting produced nine clusters and 13 single isolates, with a high D value of 0.9248. RAPD fingerprinting produced six clusters and 13 single isolates, with a relatively low D value of 0.7776. ERIC-PCR analysis proved to have better discrimination capability than RAPD analysis and generated better clustering for all proteobacterium species isolates. We conclude that ERIC-PCR is a robust, reliable and rapid molecular typing method for discriminating different genera of proteobacteria.
  14. Sun S, Tan LT, Fang YL, Jin ZJ, Zhou L, Goh BH, et al.
    Mol Plant Microbe Interact, 2020 Mar;33(3):488-498.
    PMID: 31710580 DOI: 10.1094/MPMI-09-19-0264-R
    Phenazine-1-carboxylic acid (PCA) is the primary active component in the newly registered, commercial biopesticide Shenqinmycin and is produced during fermentation by the engineered rhizobacterium strain Pseudomonas PA1201. Both phz1 and phz2 gene clusters contribute to PCA biosynthesis. In this study, we evaluated the role of OxyR in the regulation of PCA biosynthesis in PA1201. We first showed a functional link between oxyR expression and PCA biosynthesis. Deletion of oxyR and overexpression of oxyR both increase PCA biosynthesis. The molecular mechanisms underlying OxyR regulation of PCA production were investigated using several approaches. OxyR acts divergently in phz1 and phz2. Overexpression of oxyR activated the expression of phz1 and phz1-dependent PCA production. However, overexpression of oxyR had little effect on phz2-dependent PCA biosynthesis, while deletion of oxyR promoted phz2-dependent PCA production and exerted a negative effect on phz2 expression. Further, OxyR directly bound to the phz2 promoter region. In addition, the regulation of PCA biosynthesis by OxyR was associated with quorum sensing (QS) systems. Overexpression of OxyR positively regulated pqs QS system. Finally, transcriptomic analysis and subsequent genetic analysis revealed the small RNA phrS plays a key role in OxyR-dependent PCA accumulation. Specifically, OxyR directly binds to the phrS promoter region to positively regulate phrS expression wherein PhrS regulates the PCA positive regulator MvfR in order to control PCA biosynthesis.
  15. Azad SM, Jin Y, Ser HL, Goh BH, Lee LH, Thawai C, et al.
    J Appl Microbiol, 2022 Feb;132(2):772-784.
    PMID: 34260807 DOI: 10.1111/jam.15222
    Extensively produced by members of the genus Streptomyces, piericidins are a large family of microbial metabolites, which consist of main skeleton of 4-pyridinol with methylated polyketide side chain. Nonetheless, these metabolites show differences in their bioactive potentials against micro-organisms, insects and tumour cells. Due to its close structural similarity with coenzyme Q, piericidins also possess an inhibitory activity against NADH dehydrogenase as well as Photosystem II. This review studied the latest research progress of piericidins, covering the chemical structure and physical properties of newly identified members, bioactivities, biosynthetic pathway with gene clusters and future prospect. With the increasing incidence of drug-resistant human pathogen strains and cancers, this review aimed to provide clues for the development of either new potential antibiotics or anti-tumour agents.
  16. Cui Y, Song K, Jin ZJ, Lee LH, Thawai C, He YW
    Synth Syst Biotechnol, 2023 Dec;8(4):618-628.
    PMID: 37823038 DOI: 10.1016/j.synbio.2023.09.004
    Biocontrol strain Pseudomonas PA1201 produces pyoluteorin (Plt), which is an antimicrobial secondary metabolite. Plt represents a promising candidate pesticide due to its broad-spectrum antifungal and antibacterial activity. Although PA1201 contains a complete genetic cluster for Plt biosynthesis, it fails to produce detectable level of Plt when grown in media typically used for Pseudomonas strains. In this study, minimum medium (MM) was found to favor Plt biosynthesis. Using the medium M, which contains all the salts of MM medium except for mannitol, as a basal medium, we compared 10 carbon sources for their ability to promote Plt biosynthesis. Fructose, mannitol, and glycerol promoted Plt biosynthesis, with fructose being the most effective carbon source. Glucose or succinic acid had no significant effect on Plt biosynthesis, but effectively antagonized fructose-dependent synthesis of Plt. Promoter-lacZ fusion reporter strains demonstrated that fructose acted through activation of the pltLABCDEFG (pltL) operon but had no effect on other genes of plt gene cluster; glucose or succinic acid antagonized fructose-dependent pltL induction. Mechanistically, fructose-mediated Plt synthesis involved carbon catabolism repression. The two-component system CbrA/CbrB and small RNA catabolite repression control Z (crcZ) were essential for fructose-induced Plt synthesis. The small RNA binding protein Hfq and Crc negatively regulated fructose-induced Plt. Taken together, this study provides a new model of fructose-dependent Plt production in PA1201 that can help improve Plt yield by biosynthetic approaches.
  17. Kow CS, Lee LH, Ramachandram DS, Hasan SS, Ming LC, Goh HP
    Immun Inflamm Dis, 2022 Feb;10(2):255-264.
    PMID: 34970856 DOI: 10.1002/iid3.562
    BACKGROUND: Overactivation of the NLR family pyrin domain containing 3 (NLRP3) inflammasome can lead to severe illness in patients with coronavirus disease-2019 (COVID-19). The NLRP3 inhibitor, colchicine, therefore, appears to be promising for the treatment of COVID-19.

    AIMS: We aimed to perform a meta-analysis of randomized trials investigating the effect of colchicine in patients with COVID-19.

    MATERIALS & METHODS: We systematically searched electronic databases and clinical trial registries (up to October 17, 2021) for eligible studies. The outcomes of interest were all-cause mortality and duration of hospital stay. Meta-analysis with the random-effects model was used to estimate the pooled odds ratio (OR) of mortality and 95% confidence interval (CI). The pooled standardized mean difference of duration of hospital stay with 95% CI between colchicine users and non-colchicine users was estimated using Cohen's d index.

    RESULTS: The meta-analyses revealed no significant difference in the odds of mortality (pooled OR = 0.76; 95% CI: 0.53-1.07), but a significant reduction in the duration of hospital stay with the use of colchicine (pooled standardized mean difference = -0.59; 95% CI: -1.06 to -0.13).

    DISCUSSION AND CONCLUSION: The ability of colchicine to reduce the length of stay in hospitalized patients with COVID-19 is consistent with its potential to prevent clinical deterioration via inhibition of NLRP3 inflammasome. Nevertheless, such beneficial effects of colchicine did not translate into mortality benefits in patients with COVID-19.

  18. Tan LT, Ser HL, Yin WF, Chan KG, Lee LH, Goh BH
    Front Microbiol, 2015;6:1316.
    PMID: 26635777 DOI: 10.3389/fmicb.2015.01316
    A Streptomyces strain, MUM256 was isolated from Tanjung Lumpur mangrove soil in Malaysia. Characterization of the strain showed that it has properties consistent with those of the members of the genus Streptomyces. In order to explore the potential bioactivities, extract of the fermented broth culture of MUM256 was prepared with organic solvent extraction method. DPPH and SOD activity were utilized to examine the antioxidant capacity and the results have revealed the potency of MUM256 in superoxide anion scavenging activity in dose-dependent manner. The cytotoxicity of MUM256 extract was determined using cell viability assay against 8 different panels of human cancer cell lines. Among all the tested cancer cells, HCT116 was the most sensitive toward the extract treatment. At the highest concentration of tested extract, the result showed 2.3-, 2.0-, and 1.8-folds higher inhibitory effect against HCT116, HT29, and Caco-2 respectively when compared to normal cell line. This result has demonstrated that MUM256 extract was selectively cytotoxic toward colon cancer cell lines. In order to determine the constituents responsible for its bioactivities, the extract was then subjected to chemical analysis using GC-MS. The analysis resulted in the identification of chemical constituents including phenolic and pyrrolopyrazine compounds which may responsible for antioxidant and anticancer activities observed. Based on the findings of this study, the presence of bioactive constituents in MUM256 extract could be a potential source for the development of antioxidative and chemopreventive agents.
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