Displaying publications 41 - 60 of 106 in total

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  1. Kumar S, Kaushik A, Narasimhan B, Shah SAA, Lim SM, Ramasamy K, et al.
    BMC Chem, 2019 Dec;13(1):85.
    PMID: 31384832 DOI: 10.1186/s13065-019-0601-z
    Pyrimidine nucleus is a significant pharmacophore that exhibited excellent pharmacological activities. A series of pyrimidine scaffolds was synthesized and its chemical structures were confirmed by physicochemical and spectral analysis. The synthesized compounds were evaluated for their antimicrobial potential towards Gram positive and negative bacteria as well as fungal species. They were also assessed for their anticancer activity toward a human colorectal carcinoma cell line (HCT116). Whilst results of antimicrobial potential revealed that compounds Ax2, Ax3, Ax8 and Ax14 exhibited better activity against tested microorganisms, the results of antiproliferative activity indicated that compounds Ax7 and Ax10 showed excellent activity against HCT116. Further, the molecular docking of pyrimidine derivatives Ax1, Ax9 and Ax10 with CDK8 (PDB id: 5FGK) protein indicated that moderate to better docking results within the binding pocket. Compounds Ax8 and Ax10 having significant antimicrobial and anticancer activities may be selected as lead compounds for the development of novel antimicrobial and anticancer agent, respectively.
  2. 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).

  3. 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.
  4. Neoh CF, Long CM, Lim SM, Ramasamy K, Shahar S, Majeed ABA
    Geriatr Gerontol Int, 2017 Aug;17(8):1214-1220.
    PMID: 27489036 DOI: 10.1111/ggi.12849
    AIM: The present study assessed adherence, barriers, belief and awareness towards the use of medications among multi-ethnic community-dwelling older adults in Malaysia. Medication accessibility, expenditure and perceptions towards medicine labeling among older adults were also evaluated.

    METHODS: A cross-sectional study was carried out in the central region of Malaysia from January to August 2015. The older adults enrolled in an ongoing prospective community-based geriatric cohort study and prescribed with medicines were interviewed using a 50-item validated questionnaire.

    RESULTS: Of the 79 older adults interviewed, 39.2% had ≥4 prescribed medications. Most obtained their medications free-of-charge from government hospitals (66, 83.5%). Nearly half (35, 44.3%) had trouble reading labels for medicines that they had received. Chinese older adults (P = 0.001) and those with lower monthly household income (P 

  5. Rahim NS, Lim SM, Mani V, Abdul Majeed AB, Ramasamy K
    Pharm Biol, 2017 Dec;55(1):825-832.
    PMID: 28118770 DOI: 10.1080/13880209.2017.1280688
    CONTEXT: Virgin coconut oil (VCO) has been reported to possess antioxidative, anti-inflammatory and anti-stress properties.

    OBJECTIVE: Capitalizing on these therapeutic effects, this study investigated for the first time the potential of VCO on memory improvement in vivo.

    MATERIALS AND METHODS: Thirty male Wistar rats (7-8 weeks old) were randomly assigned to five groups (n = six per group). Treatment groups were administered with 1, 5 and 10 g/kg VCO for 31 days by oral gavages. The cognitive function of treated-rats were assessed using the Morris Water Maze Test. Brains were removed, homogenized and subjected to biochemical analyses of acetylcholine (ACh) and acetylcholinesterase (AChE), antioxidants [superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), glutathione peroxidase (GPx) and glutathione reductase (GRx)], lipid peroxidase [malondialdehyde (MDA)] as well as nitric oxide (NO). α-Tocopherol (αT; 150 mg/kg) was also included for comparison purposes.

    RESULTS: VCO-fed Wistar rats exhibited significant (p  33%) and NO (≥ 34%). Overall, memory improvement by VCO was comparable to αT.

    DISCUSSION AND CONCLUSION: VCO has the potential to be used as a memory enhancer, the effect of which was mediated, at least in part, through enhanced cholinergic activity, increased antioxidants level and reduced oxidative stress.

  6. Yadav S, Lim SM, Ramasamy K, Vasudevan M, Shah SAA, Mathur A, et al.
    Chem Cent J, 2018 May 26;12(1):66.
    PMID: 29804151 DOI: 10.1186/s13065-018-0432-3
    BACKGROUND: The study describes the synthesis, characterization, in vitro antimicrobial and anticancer evaluation of a series of 2-(1-benzoyl-1H-benzo[d]imidazol-2-ylthio)-N-substituted acetamide derivatives. The synthesized derivatives were also assessed for in vitro antitubercular activity against Mycobacterium tuberculosis H37Rv. The compounds found active in in vitro study were assessed for their in vivo antitubercular activity in mice models and for their inhibitory action on vital mycobacterial enzymes viz, isocitrate lyase, pantothenate synthetase and chorismate mutase.

    RESULTS: Compounds 8, 9 and 11 emerged out as excellent antimicrobial agents in antimicrobial assays when compared to standard antibacterial and antifungal drugs. The results of anticancer activity displayed that majority of the derivatives were less cytotoxic than standard drugs (tamoxifen and 5-fluorouracil) towards MCF7 and HCT116 cell lines. However, compound 2 (IC50 = 0.0047 µM/ml) and compound 10 (IC50 = 0.0058 µM/ml) showed highest cytotoxicity against MCF7 and HCT116 cell lines, respectively. The results of in vivo antitubercular activity revealed that a dose of 1.34 mg/kg was found to be safe for the synthesized compounds. The toxic dose of the compounds was 5.67 mg/kg while lethal dose varied from 1.81 to 3.17 mg/kg body weight of the mice. Compound 18 inhibited all the three mycobacterial enzymes to the highest level in comparison to the other synthesized derivatives but showed lesser inhibition as compared to streptomycin sulphate.

    CONCLUSIONS: A further research on most active synthesized compounds as lead molecules may result in discovery of novel anticancer and antitubercular agents.

  7. Fareez IM, Lim SM, Zulkefli NAA, Mishra RK, Ramasamy K
    Probiotics Antimicrob Proteins, 2018 09;10(3):543-557.
    PMID: 28493103 DOI: 10.1007/s12602-017-9284-8
    The susceptibility of probiotics to low pH and high temperature has limited their use as nutraceuticals. In this study, enhanced protection of probiotics via microencapsulation was achieved. Lactobacillus plantarum LAB12 were immobilised within polymeric matrix comprised of alginate (Alg) with supplementation of cellulose derivatives (methylcellulose (MC), sodium carboxymethyl cellulose (NaCMC) or hydroxypropyl methylcellulose (HPMC)). L. plantarum LAB12 encapsulated in Alg-HPMC(1.0) and Alg-MC(1.0) elicited improved survivability (91%) in simulated gastric conditions and facilitated maximal release (∼100%) in simulated intestinal condition. Alg-HPMC(1.0) and Alg-MC(1.0) significantly reduced (P 7 log CFU g-1. Alg-MC and Alg-HPMC improved the survival of LAB12 against simulated gastric condition (9.24 and 9.55 log CFU g-1, respectively), temperature up to 90 °C (9.54 and 9.86 log CFU g-1, respectively) and 4-week of storage at 4 °C (8.61 and 9.23 log CFU g-1, respectively) with sustained release of probiotic in intestinal condition (>9 log CFU g-1). These findings strongly suggest the potential of cellulose derivatives supplemented Alg bead as protective micro-transport for probiotic strains. They can be safely incorporated into new functional food or nutraceutical products.
  8. Mani V, Jaafar SM, Azahan NSM, Ramasamy K, Lim SM, Ming LC, et al.
    Life Sci, 2017 Jul 01;180:23-35.
    PMID: 28501482 DOI: 10.1016/j.lfs.2017.05.013
    AIM: The present study is aimed to investigate the ability of ciproxifan, a histamine H3 receptor antagonist to inhibit β-amyloid (Aβ)-induced neurotoxicity in SK-N-SH cells and APP transgenic mouse model.

    MATERIALS AND METHODS: In vitro studies was designed to evaluate the neuroprotective effects of ciproxifan in Aβ25-35 - induced SK-N-SH cells. For the in vivo study, ciproxifan (1 and 3mg/kg, i.p.) was administrated to transgenic mice for 15days and behaviour was assessed using the radial arm maze (RAM). Brain tissues were collected to measure Aβ levels (Aβ1-40 and Aβ1-42), acetylcholine (ACh), acetylcholinesterase (AChE), nitric oxide (NO), lipid peroxidation (LPO), antioxidant activities, cyclooxygenases (COX) and cytokines (IL-1α, IL-1β and IL-6), while plasma was collected to measure TGF-1β.

    RESULTS: The in vitro studies demonstrated neuroprotective effect of ciproxifan by increasing cell viability and inhibiting reactive oxygen species (ROS) in Aβ25-35-induced SK-N-SH cells. Ciproxifan significantly improved the behavioural parameters in RAM. Ciproxifan however, did not alter the Aβ levels in APP transgenic mice. Ciproxifan increased ACh and showed anti-oxidant properties by reducing NO and LPO levels as well as enhancing antioxidant levels. The neuroinflammatory analysis showed that ciproxifan reduced both COX-1 and COX-2 activities, decreased the level of pro-inflammatory cytokines IL-1α, IL-1β and IL-6 and increased the level of anti-inflammatory cytokine TGF-1β.

    CONCLUSION: This present study provides scientific evidence of the use of ciproxifan via antioxidant and cholinergic pathways in the management of AD.

  9. Kumar S, Lim SM, Ramasamy K, Mani V, Shah SAA, Narasimhan B
    Chem Cent J, 2018 Jun 25;12(1):73.
    PMID: 29938365 DOI: 10.1186/s13065-018-0440-3
    BACKGROUND: Pyrimidine molecules attracted organic chemists very much due to their biological and chemotherapeutic importance. Their related fused heterocycles are of interest as potential bioactive molecules so, we have designed and prepared a new class of 4,4'-(1,4-phenylene)bis(pyrimidin-2-amine) molecules and screened for their in vitro antibacterial, antifungal and cytotoxicity studies.

    RESULTS: The structures of synthesized bis-pyrimidine molecules were confirmed by physicochemical and spectral means. The synthesized compounds were further evaluated for their in vitro biological potentials i.e. antimicrobial activity using tube dilution method and anticancer activity against human colorectal carcinoma (HCT116) cancer cell line by Sulforhodamine B assay.

    CONCLUSIONS: The biological study demonstrated that compounds s7, s8, s11, s14, s16, s17 and s18 have shown more promising antimicrobial activity with best MIC values than the cefadroxil (antibacterial) and fluconazole (antifungal) and compound s3 found to have better anticancer activity against human colorectal carcinoma (HCT116) cancer cell line.

  10. Tahlan S, Narasimhan B, Lim SM, Ramasamy K, Mani V, Shah SAA
    Mini Rev Med Chem, 2019;19(13):1080-1092.
    PMID: 30306865 DOI: 10.2174/1389557518666181009151008
    BACKGROUND: Increased rate of mortality due to the development of resistance to currently available antimicrobial and anticancer agents initiated the need to develop new chemical entities for the treatment of microbial infections and cancer.

    OBJECTIVE: The present study was aimed to synthesize and evaluate antimicrobial and anticancer activities of Schiff bases of 2-mercaptobenzimidazole.

    METHODS: The Schiff bases of 2-mercaptobenzimidazole were synthesized from 4-(2-(1H-benzo[d]- imidazol-2-ylthio)acetamido)benzohydrazide. The synthesized compounds were evaluated for antimicrobial and anticancer activities by tube dilution method and Sulforhodamine-B (SRB) assay, respectively.

    RESULTS: Compounds 8 (MICpa, an = 2.41, 1.20 µM/ml), 10 (MICse, sa = 2.50 µM/ml), 20 (MICec = 2.34 µM/ml) and 25 (MICca = 1.46 µM/ml) showed significant antimicrobial activity against tested bacterial and fungal strains and compounds 20 (IC50 = 8 µg/ml) and 23 (IC50 = 7 µg/ml) exhibited significant anticancer activity.

    CONCLUSION: In general, the synthesized derivatives exhibited moderate antimicrobial and anticancer activities. Compounds 8 and 25 having high antifungal potential among the synthesized compounds may be taken as lead molecules for the development of novel antifungal agents.

  11. Kumar S, Narasimhan B, Lim SM, Ramasamy K, Mani V, Shah SAA
    Mini Rev Med Chem, 2019;19(10):851-864.
    PMID: 30306864 DOI: 10.2174/1389557518666181009141924
    BACKGROUND: A series of 5-(2-amino-6-(3/4-bromophenyl)pyrimidin-4-yl)benzene-1,3-diol scaffolds was synthesized by Claisen-Schmidt condensation and characterized by NMR, IR, Mass and elemental analyses.

    METHODS: The synthesized pyrimidine scaffolds were screened for their antimicrobial activity by tube dilution method as well for antiproliferative activity (human colorectal (HCT116) cancer cell line) by SRB assay.

    RESULTS: The antimicrobial screening results demonstrated that compounds, k6, k12, k14 and k20 were found to be the most potent ones against selected microbial species. The anticancer screening results indicated that compounds, k8 and k14 displayed potent anticancer activity against cancer cell line (HCT116).

    CONCLUSION: Further, the molecular docking study carried to find out the interaction between active pyrimidine compounds with CDK-8 protein indicated that compound k14 showed best dock score with better potency within the ATP binding pocket and may be used as a lead for rational drug designing of the anticancer molecule.

  12. Kumar S, Singh J, Narasimhan B, Shah SAA, Lim SM, Ramasamy K, et al.
    Chem Cent J, 2018 Oct 22;12(1):106.
    PMID: 30345469 DOI: 10.1186/s13065-018-0475-5
    BACKGROUND: Pyrimidine is an important pharmacophore in the field of medicinal chemistry and exhibit a broad spectrum of biological potentials. A study was carried out to identify the target protein of potent bis-pyrimidine derivatives using reverse docking program. PharmMapper, a robust online tool was used for identifying the target proteins based on reverse pharmacophore mapping. The murine macrophage (RAW 264.7) and human embryonic kidney (HEK-293) cancer cell line used for selectivity and safety study.

    METHODS: An open web server PharmMapper was used to identify the possible target of the developed compounds through reverse pharmacophore mapping. The results were analyzed and validated through docking with Schrodinger v9.6 using 10 protein GTPase HRas selected as possible target. The docking studies with Schrödinger validated the binding behavior of bis-pyrimidine compounds within GTP binding pocket. MTT and sulforhodamine assay were used as antiproliferative activity.

    RESULTS AND DISCUSSION: The protein was found one of the top scored targets of the compound 18, hence, the GTPase HRas protein was found crucial to be targeted for competing cancer. Toxicity study demonstrated the significant selectivity of most active compounds, 12, 16 and 18 showed negligible cell toxicity at their IC50 concentration.

    CONCLUSION: From the results, we may conclude that GTPase HRas as a possible target of studied bis-pyrimidine derivatives where the retrieved information may be quite useful for rational drug designing.

  13. Kakkar S, Tahlan S, Lim SM, Ramasamy K, Mani V, Shah SAA, et al.
    Chem Cent J, 2018 Aug 12;12(1):92.
    PMID: 30101384 DOI: 10.1186/s13065-018-0459-5
    BACKGROUND: A new series of benzoxazole analogues was synthesized and checked for their in vitro antibacterial, antifungal and anticancer activities.

    RESULTS AND DISCUSSION: The synthesized benzoxazole compounds were confirmed by IR, 1H/13C-NMR, mass and screened for their in vitro antimicrobial activity against Gram-positive bacterium: Bacillus subtilis, four Gram-negative bacteria: Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Salmonella typhi and two fungal strains: Candida albicans and Aspergillus niger using tube dilution technique and minimum inhibitory concentration (MIC) was noted in µM and compared to ofloxacin and fluconazole. Human colorectal carcinoma (HCT116) cancer cell line was used for the determination of in vitro anticancer activity (IC50 value) by Sulforhodamine B assay using 5-fluorouracil as standard drug.

    CONCLUSION: The performed study indicated that the compounds 1, 10, 13, 16, 19, 20 and 24 had highest antimicrobial activity with MIC values comparable to ofloxacin and fluconazole and compounds 4, 6, 25 and 26 had best anticancer activity in comparison to 5-fluorouracil.

  14. Kakkar S, Kumar S, Narasimhan B, Lim SM, Ramasamy K, Mani V, et al.
    Chem Cent J, 2018 Sep 19;12(1):96.
    PMID: 30232633 DOI: 10.1186/s13065-018-0464-8
    BACKGROUND: Benzoxazole is the most important class of heterocyclic compound in medicinal chemistry. It has been incorporated in many medicinal compounds making it a versatile heterocyclic compound that possess a wide spectrum of biological activities.

    RESULTS: The molecular structures of synthesized benzoxazole derivatives were confirmed by physicochemical and spectral means. The synthesized compounds were further evaluated for their in vitro biological potentials i.e. antimicrobial activity against selected microbial species using tube dilution method and antiproliferative activity against human colorectal carcinoma (HCT 116) cancer cell line by Sulforhodamine B assay.

    CONCLUSION: In vitro antimicrobial results demonstrated that compounds 4, 5, 7 and 16 showed promising antimicrobial potential. The in vitro anticancer activity indicated that compounds 4 and 16 showed promising anticancer activity against human colorectal cancer cell line (HCT 116) when compared to standard drug and these compounds may serve as lead compound for further development of novel antimicrobial and anticancer agents.

  15. Kashyap S, Kumar S, Ramasamy K, Lim SM, Shah SAA, Om H, et al.
    Chem Cent J, 2018 Nov 20;12(1):117.
    PMID: 30460466 DOI: 10.1186/s13065-018-0487-1
    BACKGROUND: The transition metal complexes formed from Schiff base is regarded as leading molecules in medicinal chemistry. Because of the preparative availability and diversity in the structure of central group, the transition metals are important in coordination chemistry. In the present work, we have designed and prepared Schiff base and its metal complexes (MC1-MC4) and screened them for antimicrobial, anticancer and corrosion inhibitory properties.

    METHODOLOGY: The synthesized metal complexes were characterized by physicochemical and spectral investigation (UV, IR, 1H and 13C-NMR) and were further evaluated for their antimicrobial (tube dilution) and anticancer (SRB assay) activities. In addition, the corrosion inhibition potential was determined by electrochemical impedance spectroscopy (EIS) technique.

    RESULTS AND DISCUSSION: Antimicrobial screening results found complexes (MC1-MC4) to exhibit less antibacterial activity against the tested bacterial species compared to ofloxacin while the complex MC1 exhibited greater antifungal activity than the fluconazole. The anticancer activity results found the synthesized Schiff base and its metal complexes to elicit poor cytotoxic activity than the standard drug (5-fluorouracil) against HCT116 cancer cell line. Metal complex MC2 showed more corrosion inhibition efficiency with high Rct values and low Cdl values.

    CONCLUSION: From the results, we can conclude that complexes MC1 and MC2 may be used as potent antimicrobial and anticorrosion agents, respectively.

  16. Kakkar S, Kumar S, Lim SM, Ramasamy K, Mani V, Shah SAA, et al.
    Chem Cent J, 2018 Dec 04;12(1):130.
    PMID: 30515643 DOI: 10.1186/s13065-018-0499-x
    BACKGROUND: In view of wide range of biological activities of oxazole, a new series of oxazole analogues was synthesized and its chemical structures were confirmed by spectral data (Proton/Carbon-NMR, IR, MS etc.). The synthesized oxazole derivatives were screened for their antimicrobial and antiproliferative activities.

    RESULTS AND DISCUSSION: The antimicrobial activity was performed against selected fungal and bacterial strains using tube dilution method. The antiproliferative potential was evaluated against human colorectal carcinoma (HCT116) and oestrogen- positive human breast carcinoma (MCF7) cancer cell lines using Sulforhodamine B assay and, results were compared to standard drugs, 5-fluorouracil and tamoxifen, respectively.

    CONCLUSION: The performed antimicrobial activity indicated that compounds 3, 5, 6, 8 and 14 showed promising activity against selected microbial species. Antiproliferative screening found compound 14 to be the most potent compound against HCT116 (IC50 = 71.8 µM), whereas Compound 6 was the most potent against MCF7 (IC50 = 74.1 µM). Further, the molecular docking study has been carried to find out the interaction between active oxazole compounds with CDK8 (HCT116) and ER-α (MCF7) proteins indicated that compound 14 and 6 showed good dock score with better potency within the ATP binding pocket and may be used as a lead for rational drug designing of the anticancer molecule.

  17. 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.
  18. Mishra A, Tahlan S, Ramasamy K, Lim SM, Shah SAA, Narasimhan B
    Mini Rev Med Chem, 2020;20(13):1311-1317.
    PMID: 32368977 DOI: 10.2174/1389557520666200505124125
    BACKGROUND: Being derived from primary amine and aromatic aldehyde, Schiff base and their complexes have an imperative role in the improvement of inorganic chemistry, which are broadly studied as coordination compounds and are gradually becoming more important in biochemical and analytical applications.

    METHODS: They have also been used for antibacterial, antifungal, anticancer, antitubercular activities. Novel synthesised Schiff's base 2-methoxy-4-((3-methylpyridin-2-ylimino)methyl)phenol (SB) and its metal complexes (Zn[II], Cu[II], Co[II] and Ni[II]) were characterised by UV, IR and NMR spectroscopy. Formation of the Schiff base and the metal (Zn[II], Cu[II], Co[II] and Ni[II]) chelates was supported by spectral and analytical data. The ligand and metal complexes have been screened for their antibacterial activity against Staphylococcus aureus, Salmonella typhi, Escherichia coli, Klebsiella pneumoniae and antifungal activity against the fungi Candida albicans and Aspergillus niger. Further, the synthesised compounds were also screened for antiproliferative activity against the human colorectal carcinoma (HCT116) cell line using the Sulforhodamine B assay.

    RESULT: Metal complexes formed were found to enhance the potency of the Schiff base due to coordination with a copper complex, showing better activity than others.

    CONCLUSION: Copper complex was observed to be more potent than other complexes against all the pathogenic microbes and cancer cell line (HCT116).

  19. Md Hamzah N, Lim SM, Vijayanathan Y, Lim FT, Abdul Majeed AB, Tan MP, et al.
    J Vis Exp, 2021 Dec 28.
    PMID: 35037659 DOI: 10.3791/63355
    The limitations of current treatments in delaying dopaminergic neuronal loss in Parkinson's disease (PD) raise the need for alternative therapies that can restore these neurons. Much effort is currently directed toward a better understanding of neuroregeneration using preclinical in vivo models. This regenerative capability for self-repair is, however, inefficient in mammals. Non-mammalian animals like zebrafish have thus emerged as an excellent neuroregenerative model due to its capability to continuously self-renew and have a close brain homology to humans. As part of the effort in elucidating cellular events involved in neuroregeneration in vivo, we have established the 6-hydroxydopamine (6-OHDA)-induced adult zebrafish-based PD model. This was achieved through the optimized intracerebroventricular (ICV) microinjection of 99.96 mM 6-OHDA to specifically ablate dopaminergic neurons (DpN) in the ventral diencephalon (Dn) of zebrafish brain. Immunofluorescence indicated more than 85% of DpN ablation at day three postlesion and full restoration of DpN at lesioned site 30 days postlesion. The present study determined the impairment and subsequent recovery of zebrafish swimming behavior following lesion by using the open field test through which two parameters, distance traveled (cm) and mean speed (cm/s), were quantified. The locomotion was assessed by analyzing the recordings of individual fish of each group (n = 6) using video tracking software. The findings showed a significant (p < 0.0001) reduction in speed (cm/s) and distance traveled (cm) of lesioned zebrafish 3 days postlesion when compared to sham. The lesioned zebrafish exhibited full recovery of swimming behavior 30 days postlesion. The present findings suggest that 6-OHDA lesioned adult zebrafish is an excellent model with reproducible quality to facilitate the study of neuroregeneration in PD. Future studies on the mechanisms underlying neuroregeneration as well as intrinsic and extrinsic factors that modulate the process may provide important insight into new cell replacement treatment strategies against PD.
  20. 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 

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