Displaying publications 81 - 100 of 106 in total

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  1. Zaki RM, Ramasamy K, Ahmad Alwi NA, Mohd Yusoff R, Lim SM
    Probiotics Antimicrob Proteins, 2024 Feb;16(1):62-75.
    PMID: 36443559 DOI: 10.1007/s12602-022-10009-7
    Alzheimer's disease (AD) is characterized by aggregation of amyloid beta (Aβ) plaque. RhoA may serve as a potential target for prevention against AD given its role in the amyloidogenic pathway. The recent emergence of the gut-brain axis has linked lactic acid bacteria (LAB) to neuroprotection against AD. This study assessed the importance of RhoA inhibition in mediating the neuroprotective potential of LAB. To this end, de Man, Rogosa and Sharpe (MRS) broth fermented by lactobacilli or pediococci were tested against SK-N-SH (a human neuroblastoma cell line) in the presence of RhoA activator II for 24 h after which the RhoA activity was measured using the G-LISA Kit. Fluorescence staining of f-actin stress fibres was performed to validate RhoA inhibition. SK-N-SH was transfected with plasmid expressing amyloid precursor protein (APP) gene. The Aβ concentration in transfected cells exposed to LAB-derived cell free supernatant (CFS) in the presence of RhoA activator II was measured using the ELISA kit. Furthermore, this study measured organic acids in LAB-derived CFS using the gas chromatography. It was found that LAB-derived CFS yielded strain-dependent inhibition of RhoA, with LAB6- and LAB12-derived CFS being the most potent Pediococcal- and Lactiplantibacillus-based RhoA inhibitor, respectively. Lesser stress fibres were formed under treatment with LAB-derived CFS. The LAB-derived CFS also significantly inhibited Aβ in SK-N-SH transfected with APP gene in the presence of RhoA activator II. The LAB-derived CFS was presented with increased lactic acid, acetic acid, butyric acid and propionic acid. The present findings warrant in-depth study using animal models.
  2. Ponvel P, Shahar S, Singh DKA, Ludin AFM, Rajikan R, Rajab NF, et al.
    J Alzheimers Dis, 2021;82(2):673-687.
    PMID: 34092633 DOI: 10.3233/JAD-201607
    BACKGROUND: Cognitive frailty (CF) is identified as one of the main precursors of dementia. Multidomain intervention has been found to delay or prevent the onset of CF.

    OBJECTIVE: The aim of our present study is to determine the effectiveness of a comprehensive, multidomain intervention on CF; to evaluate its cost effectiveness and the factors influencing adherence toward this intensive intervention.

    METHODS: A total of 1,000 community dwelling older adults, aged 60 years and above will be screened for CF. This randomized controlled trial involves recruitment of 330 older adults with CF from urban, semi-urban, and rural areas in Malaysia. Multidomain intervention comprised of physical, nutritional, cognitive, and psychosocial aspects will be provided to participants in the experimental group (n = 165). The control group (n = 165) will continue their usual care with their physician. Primary outcomes include CF status, physical function, psychosocial and nutritional status as well as cognitive performance. Vascular health and gut microbiome will be assessed using blood and stool samples. A 24-month intensive intervention will be prescribed to the participants and its sustainability will be assessed for the following 12 months. The effective intervention strategies will be integrated as a personalized telerehabilitation package for the reversal of CF for future use.

    RESULTS: The multidomain intervention developed from this trial is expected to be cost effective compared to usual care as well as able is to reverse CF.

    CONCLUSION: This project will be part of the World-Wide FINGERS (Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability) Network, of which common identifiable data will be shared and harmonized among the consortia.

  3. Kumari M, Tahlan S, Narasimhan B, Ramasamy K, Lim SM, Shah SAA, et al.
    BMC Chem, 2021 Jan 21;15(1):5.
    PMID: 33478538 DOI: 10.1186/s13065-020-00717-y
    BACKGROUND: Triazole is an important heterocyclic moiety that occupies a unique position in heterocyclic chemistry, due to its large number of biological activities. It exists in two isomeric forms i.e. 1,2,4-triazole and 1,2,3-triazole and is used as core molecule for the design and synthesis of many medicinal compounds. 1,2,4-Triazole possess broad spectrum of therapeutically interesting drug candidates such as analgesic, antiseptic, antimicrobial, antioxidant, anti-urease, anti-inflammatory, diuretics, anticancer, anticonvulsant, antidiabetic and antimigraine agents.

    METHODS: The structures of all synthesized compounds were characterized by physicochemical properties and spectral means (IR and NMR). The synthesized compounds were evaluated for their in vitro antimicrobial activity against Gram-positive (B. subtilis), Gram-negative (P. aeruginosa and E. coli) bacterial and fungal (C. albicans and A. niger) strains by tube dilution method using ciprofloxacin, amoxicillin and fluconazole as standards. In-vitro antioxidant and anti-urease screening was done by DPPH assay and indophenol method, respectively. The in-vitro anticancer evaluation was carried out against MCF-7 and HCT116 cancer cell lines using 5-FU as standards.

    RESULTS, DISCUSSION AND CONCLUSION: The biological screening results reveal that the compounds T5 (MICBS, EC = 24.7 µM, MICPA, CA = 12.3 µM) and T17 (MICAN = 27.1 µM) exhibited potent antimicrobial activity as comparable to standards ciprofloxacin, amoxicillin (MICCipro = 18.1 µM, MICAmo = 17.1 µM) and fluconazole (MICFlu = 20.4 µM), respectively. The antioxidant evaluation showed that compounds T2 (IC50 = 34.83 µg/ml) and T3 (IC50 = 34.38 µg/ml) showed significant antioxidant activity and comparable to ascorbic acid (IC50 = 35.44 µg/ml). Compounds T3 (IC50 = 54.01 µg/ml) was the most potent urease inhibitor amongst the synthesized compounds and compared to standard thiourea (IC50 = 54.25 µg/ml). The most potent anticancer activity was shown by compounds T2 (IC50 = 3.84 μM) and T7 (IC50 = 3.25 μM) against HCT116 cell lines as compared to standard 5-FU (IC50 = 25.36 μM).

  4. Mookiah S, Sieo CC, Ramasamy K, Abdullah N, Ho YW
    J Sci Food Agric, 2014 Jan 30;94(2):341-8.
    PMID: 24037967 DOI: 10.1002/jsfa.6365
    In view of a worldwide attempt to restrict or ban the use of antibiotics as growth promoters in animal production, probiotics, prebiotics and combinations of both, as synbiotics, have been suggested as potential alternatives. In this study, the effects of a prebiotic (isomalto-oligosaccharides, IMO), a multi-strain probiotic (consisting of 11 Lactobacillus strains), and a combination of these dietary additives as a synbiotic on the performance, caecal bacterial populations and concentrations of caecal volatile fatty acids and non-volatile fatty acids of broiler chickens were evaluated.
  5. Ramasamy K, Abdullah N, Wong MC, Karuthan C, Ho YW
    J Sci Food Agric, 2010 Jan 15;90(1):65-9.
    PMID: 20355013 DOI: 10.1002/jsfa.3780
    Bile salt deconjugation by Lactobacillus strains is often closely linked to bile tolerance and survival of the strains in the gut and lowering of cholesterol in the host. The present study investigated the deconjugation of bile salts and removal of cholesterol by 12 Lactobacillus strains in vitro. The 12 strains were previously isolated from the gastrointestinal tract of chickens.
  6. Khoramnia A, Abdullah N, Liew SL, Sieo CC, Ramasamy K, Ho YW
    Anim Sci J, 2011 Feb;82(1):127-35.
    PMID: 21269371 DOI: 10.1111/j.1740-0929.2010.00804.x
    A rotatable central composite design (CCD) was used to study the effect of cryoprotectants (skim milk, sucrose and lactose) on the survival rate of a probiotic Lactobacillus strain, L. reuteri C10, for poultry, during freeze-drying and storage. Using response surface methodology, a quadratic polynomial equation was obtained for response value by multiple regression analyses: Y = 8.59546-0.01038 X(1)-0.09382 X(2)-0.07771 X(3)-0.054861 X(1)(2)-0.04603 X(3)(2)-0.10938 X(1)X(2). Based on the model predicted, sucrose exerted the strongest effect on the survival rate. At various combinations of cryoprotectants, the viability loss of the cells after freeze-drying was reduced from 1.65 log colony forming units (CFU)/mL to 0.26-0.66 log CFU/mL. The estimated optimum combination for enhancing the survival rate of L. reuteri C10 was 19.5% skim milk, 1% sucrose and 9% lactose. Verification experiments confirmed the validity of the predicted model. The storage life of freeze-dried L. reuteri C10 was markedly improved when cryoprotectants were used. At optimum combination of the cryoprotectants, the survival rates of freeze-dried L. reuteri C10 stored at 4°C and 30°C for 6 months were 96.4% and 73.8%, respectively. Total viability loss of cells which were not protected by cryoprotectants occurred after 12 and 8 weeks of storage at 4°C and 30°C, respectively.
  7. Tang SGH, Sieo CC, Ramasamy K, Saad WZ, Wong HK, Ho YW
    BMC Vet Res, 2017 Aug 17;13(1):248.
    PMID: 28814309 DOI: 10.1186/s12917-017-1160-y
    BACKGROUND: The increasing trend of ban on the use of antibiotic growth promoters (AGPs) across the globe in the poultry industry has led to a growing need for alternatives to AGPs. Prebiotic, probiotic and their combination as a synbiotic have been considered as potential alternatives. This study aimed to investigate the effects of a prebiotic (isomaltooligosaccharide, IMO), a probiotic (PrimaLac®), and their combination (synbiotic) on hen performance, biochemical and haematological responses, and relative organ weights from 20 to 52 weeks of age.

    RESULTS: Supplementation of 1% IMO (PRE), 0.1% PrimaLac® (PRO) and 1% IMO + 0.1% PrimaLac® (SYN) improved (P 

  8. Shokryazdan P, Faseleh Jahromi M, Liang JB, Ramasamy K, Sieo CC, Ho YW
    PLoS One, 2017;12(5):e0175959.
    PMID: 28459856 DOI: 10.1371/journal.pone.0175959
    The ban or severe restriction on the use of antibiotics in poultry feeds to promote growth has led to considerable interest to find alternative approaches. Probiotics have been considered as such alternatives. In the present study, the effects of a Lactobacillus mixture composed from three previously isolated Lactobacillus salivarius strains (CI1, CI2 and CI3) from chicken intestines on performance, intestinal health status and serum lipids of broiler chickens has been evaluated. Supplementation of the mixture at a concentration of 0.5 or 1 g kg-1 of diet to broilers for 42 days improved body weight, body weight gain and FCR, reduced total cholesterol, LDL-cholesterol and triglycerides, increased populations of beneficial bacteria such as lactobacilli and bifidobacteria, decreased harmful bacteria such as E. coli and total aerobes, reduced harmful cecal bacterial enzymes such as β-glucosidase and β-glucuronidase, and improved intestinal histomorphology of broilers. Because of its remarkable efficacy on broiler chickens, the L. salivarius mixture could be considered as a good potential probiotic for chickens, and its benefits should be further evaluated on a commercial scale.
  9. Appukutty M, Radhakrishnan AK, Ramasamy K, Ramasamy R, Abdul Majeed AB, Noor MI, et al.
    BMC Res Notes, 2012;5:649.
    PMID: 23173926 DOI: 10.1186/1756-0500-5-649
    This study examined the effects of bovine colostrum on exercise -induced modulation of antioxidant parameters in skeletal muscle in mice. Adult male BALB/c mice were randomly divided into four groups (control, colostrum alone, exercise and exercise with colostrum) and each group had three subgroups (day 0, 21 and 42). Colostrum groups of mice were given a daily oral supplement of 50 mg/kg body weight of bovine colostrum and the exercise group of mice were made to exercise on the treadmill for 30 minutes per day. Total antioxidants, lipid hydroperoxides, xanthine oxidase and super oxide dismutase level was assayed from the homogenate of hind limb skeletal muscle.
  10. Kumar P, Narasimhan B, Ramasamy K, Mani V, Mishra RK, Majeed ABA, et al.
    Monatsh Chem, 2013;144(6):825-849.
    PMID: 32214480 DOI: 10.1007/s00706-012-0877-3
    ABSTRACT: A variety of N'-[4-[(substituted imino)methyl]benzylidene]-substituted benzohydrazides have been synthesized and evaluated for antimicrobial and anticancer potential. Results from testing of antimicrobial activity indicated the most potent antimicrobial agents had pMIC am = 1.51. The synthesized compounds were bacteriostatic and fungistatic in action. Results from evaluation of antiviral activity indicated that none of the synthesized hydrazide derivatives inhibited viral replication at sub-toxic concentrations. Results from anti-HIV screening against HIV-2 strain ROD indicated that one compound was more potent (IC 50 ≥ 1 μg/cm3) than the standard drug nevirapine (IC 50 ≥ 4 μg/cm3) and another was equipotent (IC 50 ≥ 4 μg/cm3). The most effective anticancer agent against both HCT116 and MCF7 cancer cell lines had IC 50 = 19 and 18 μg/cm3, respectively. QSAR analysis indicated the importance of Wiener index (W) and energy of the lowest unoccupied molecular orbital (LUMO) in describing the antimicrobial activity of the synthesized compounds.
  11. Ramasamy K, Lim SM, Abu Bakar H, Ismail N, Ismail MS, Ali MF, et al.
    Phytother Res, 2010 May;24(5):640-3.
    PMID: 19468989 DOI: 10.1002/ptr.2891
    Endophytes, which are receiving increasing attention, have been found to be potential sources of bioactive metabolites following the discovery of paclitaxel producing endophytic fungi. In the present study, a total of 348 endophytes were isolated from different parts of 24 Malaysian medicinal plants. Three selected endophytes (HAB10R12, HAB11R3 and HAB21F25) were investigated for their antimicrobial and cytotoxic activities. For antimicrobial activity, HAB10R12 and HAB11R3 were found to be most active against bacteria and fungi, respectively. Their antimicrobial effects were comparable to, if not better than, a number of current commercial antibacterial and antifungal agents. Both HAB10R12 and HAB21F25 were found to be potential anticancer drug candidates, having potent activity against MCF-7 and HCT116 cell lines and warrant further investigation.
  12. Samah S, Neoh CF, Wong YY, Hassali MA, Shafie AA, Lim SM, et al.
    Res Social Adm Pharm, 2017 11;13(6):1135-1141.
    PMID: 27825607 DOI: 10.1016/j.sapharm.2016.10.017
    BACKGROUND: Quality of life (QoL) assessment provides valuable outcome to support clinical decision-making, particularly for patients with chronic diseases that are incurable. A brief, 15-item diabetes-specific tool [i.e. Diabetes Quality of Life-Brief Clinical Inventory (DQoL-BCI)] is known to be developed in English and validated for use in clinical practice. This simplified tool, however, is not readily available for use in the Malaysian setting.

    OBJECTIVE: To translate the DQoL-BCI into a Malaysian version and to assess its construct validity (factorial validity, convergent validity and discriminant validity), reliability (internal consistency) and floor and ceiling effects among the Malaysian diabetic population.

    MATERIAL AND METHODS: A forward-backward translation, involving professional translators and experts with vast experience in translation of patient reported outcome measures, was conducted. A total of 202 patients with Type 2 diabetes mellitus (T2DM) who fulfilled the inclusion criteria were invited to complete the translated DQoL-BCI. Data were analysed using SPSS for exploratory factor analysis (EFA), convergent and discriminant validity, reliability and test-retest, and AMOS software for confirmatory factor analysis (CFA).

    RESULTS: Findings from EFA indicated that the 4-factor structure of the Malaysian version of DQoL-BCI was optimal and explained 50.9% of the variance; CFA confirmed the 4-factor model fit. There was negative, moderate correlation between the scores of DQoL-BCI (Malaysian version) and EQ-5D-3L utility score (r = -0.329, p = 0.003). Patients with higher glycated haemoglobin levels (p = 0.008), diabetes macrovascular (p = 0.017) and microvascular (p = 0.013) complications reported poorer QoL. Cronbach's alpha coefficient and intraclass coefficient correlations (range) obtained were 0.703 and 0.86 (0.734-0.934), indicating good reliability and stability of the translated DQoL-BCI.

    CONCLUSION: This study had validated the linguistic and psychometric properties of DQoL-BCI (Malaysian version), thus providing a valid and reliable brief tool for assessing the QoL of Malaysian T2DM patients.

  13. Ahmad N, Anouar EH, Tajuddin AM, Ramasamy K, Yamin BM, Bahron H
    PLoS One, 2020;15(4):e0231147.
    PMID: 32287324 DOI: 10.1371/journal.pone.0231147
    This paper reports the synthesis, characterization, anticancer screening and quantum chemical calculation of a tetradentate Schiff base 2,2'-((1E,1'E)-((2,2-dimethylpropane-1,3-diyl)bis- (azanylylidene))bis(methanylylidene))bis(4-fluorophenol) (L2F) and its Pd (II) complex (PdL2F). The compounds were characterized via UV-Visible, NMR, IR spectroscopy and single crystal x-ray diffraction. Density Functional Theory (DFT) and time-dependent DFT calculations in gas and solvent phases were carried out using B3LYP, B3P86, CAM-B3LYP and PBE0 hybrid functionals combined with LanL2DZ basis set. Complexation of L2F to form PdL2F was observed to cause a bathochromic shift of the maximum absorption bands of n-π* from 327 to 410 nm; an upfield shift for δ (HC = N) from 8.30 to 7.96 ppm and a decreased wavenumber for ν(C = N) from 1637 to 1616 cm-1. Overall, the UV-Vis, NMR and IR spectral data are relatively well reproduced through DFT and TD-DFT methods. L2F and PdL2F showed IC50 of 90.00 and 4.10 μg/mL, respectively, against human colorectal carcinoma (HCT116) cell lines, signifying increased anticancer activity upon complexation with Pd (II).
  14. Romero Rocamora C, Ramasamy K, Meng Lim S, Majeed ABA, Agatonovic-Kustrin S
    J Pharm Biomed Anal, 2020 Jan 30;178:112909.
    PMID: 31618702 DOI: 10.1016/j.jpba.2019.112909
    A high-performance thin-layer chromatography (HPTLC) method combined with effect-directed-analysis (EDA) was developed to screen the antioxidant, neuroprotective and antidiabetic effects in essential oils derived from lavender flower, lemon myrtle, oregano, peppermint, sage, and rosemary leaves (Lamiaceae family). HPTLC hyphenated with microchemical (DPPH•, p-anisaldehyde, and ferric chloride) derivatizations, was used to evaluate antioxidant activity, presence of phytosterols and terpenoids, and polyphenolic content, while the combination with biochemical (α-amylase and acetylcholine esterase (AChE) enzymatic) derivatizations was used to asses α-amylase and AChE inhibitory activities. The superior antioxidant activity of oregano leaf extract is attributed to the presence of high levels of aromatic compounds, like polyphenolic acids. The strongest α-amylase inhibition was observed in lemon myrtle and rosemary plus extracts due to the presence of monoterpenes. Rosemary and sage extracts exhibit the highest AChE inhibition activity, with 1 μL essential oils being more potent than the recommended daily dose of donepezil. This superior neuroprotection was attributed to the presences of di- and triterpenes that displayed strong AChE inhibition and antioxidant potential in DPPH• free radical assay. Antioxidant activity was related to phenolic content (R = 0.49), while α-amylase inhibitory activity was positively related to antioxidant activity (R = 0.20) and terpenoid/sterol content (R = 0.31). AChE inhibitory activity was correlated (R = 0.80) to the combined effect of phenolics and terpenoids. Thus, the superior AChE inhibitory and neuroprotection potential of rosemary and sage essential oils could be attributed to joint effects of main phenolic and terpene constituents. The hyphenated HPTLC method provided rapid bioanalytical profiling of highly complex essential oil samples.
  15. Mohd-Zubri NS, Ramasamy K, Abdul-Rahman NZ
    Arch Oral Biol, 2022 Nov;143:105515.
    PMID: 36084351 DOI: 10.1016/j.archoralbio.2022.105515
    OBJECTIVE: This study aims to characterise the lactic acid bacteria (LAB) isolated from local Malaysian fermented foods with oral probiotics properties.

    DESIGN: The LAB strains isolated from Malaysian fermented foods, Lactobacillus brevis FT 6 and Lactobacillus plantarum FT 12, were assessed for their antimicrobial properties against Porphyromonas gingivalis ATCC 33277 via disc diffusion assay. Anti-biofilm properties were determined by treating the overnight P. gingivalis ATCC 33277 biofilm with different concentrations of LAB cell-free supernatant (LAB CFS). Quantification of biofilm was carried out by measuring the optical density of stained biofilm. The ability of L. brevis FT 6 and L. plantarum FT 12 to tolerate salivary amylase was also investigated. Acid production with different sugars was carried out by pH measurement and screening for potential antimicrobial organic acid by disc diffusion assay of neutralised probiotics CFS samples. In this study, L. rhamnosus ATCC 7469, a commercial strain was used to compare the efficacy of the isolated strain with the commercial strain.

    RESULTS: Lactobacillus brevis FT 6 and L. plantarum FT 12 possess antimicrobial activity against P. gingivalis with inhibition diameters of more than 10 mm, and the results were comparable with L. rhamnosus ATCC 7469. The MIC and MBC assay results for all tested strains were recorded to be 25 µl/µl concentration. All LAB CFS reduced biofilm formation proportionally to the CFS concentration and tolerated salivary amylase with more than 50% viability. Overnight cultures of all lactic acid bacteria strains showed a pH reduction and neutralised CFS of all lactic acid bacteria strains did not show any inhibition towards P. gingivalis.

    CONCLUSIONS: These results indicate that the isolated probiotics have the potential as probiotics to be used as a supportive oral health treatment, especially against a periodontal pathogen, P. gingivalis.

  16. Mani V, Parle M, Ramasamy K, Abdul Majeed AB
    J Sci Food Agric, 2011 Jan 15;91(1):186-92.
    PMID: 20848667 DOI: 10.1002/jsfa.4171
    Coriandrum sativum L., commonly known as coriander and belonging to the family Apiaceae (Umbelliferae), is cultivated throughout the world for its nutritional value. The present study was undertaken to investigate the effects of fresh Coriandrum sativum leaves (CSL) on cognitive functions, total serum cholesterol levels and brain cholinesterase activity in mice. In this study, CSL (5, 10 and 15% w/w of diet) was fed orally with a specially prepared diet for 45 days consecutively to experimental animals. Elevated plus-maze and passive avoidance apparatus served as the exteroceptive behavioral models for testing memory. Diazepam, scopolamine and ageing-induced amnesia served as the interoceptive behavioral models.
  17. Hazalin NA, Ramasamy K, Lim SM, Wahab IA, Cole AL, Abdul Majeed AB
    PMID: 19930582 DOI: 10.1186/1472-6882-9-46
    Endophytes, microorganisms which reside in plant tissues, have potential in producing novel metabolites for exploitation in medicine. Cytotoxic and antibacterial activities of a total of 300 endophytic fungi were investigated.
  18. Mani V, Ramasamy K, Abdul Majeed AB
    Food Funct, 2013 Apr 25;4(4):557-67.
    PMID: 23360913 DOI: 10.1039/c3fo30356j
    The fresh leaves of Murraya koenigii are often added to various dishes in Asian countries due to the delicious taste and flavour that they impart. In the present study, the effect of the total alkaloidal extract from Murraya koenigii leaves (MKA) with respect to anti-inflammatory, analgesic and anti-ulcerogenic effects were evaluated using different experimental animal models. Oral supplementation of MKA at 10, 20 and 40 mg kg(-1) body weight successfully and dose-dependently reduced the formation of oedema induced by carrageenan, histamine and serotonin as well as formaldehyde-induced arthritis. In addition, the extract (10, 20 and 40 mg kg(-1), p.o.) attenuated the writhing responses induced by an intraperitoneal injection of acetic acid and late phase of pain response induced by a subplantar injection of formalin in mice. MKA at higher doses (20 and 40 mg kg(-1), p.o) reduced the early phase response induced by formalin as well as reaction time on hot plate models. Interestingly, there was no ulcer score with the ulcerogenic effect of MKA. Moreover, all the doses of MKA (10, 20 and 40 mg kg(-1), p.o) showed promising anti-ulcerogenic activity with protection against acute gastric ulcers induced by ethanol plus hydrochloric acid and aspirin models in a dose dependent manner.
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