Displaying publications 81 - 90 of 90 in total

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  1. Khor BK, Chear NJ, Azizi J, Khaw KY
    Molecules, 2021 Mar 09;26(5).
    PMID: 33803330 DOI: 10.3390/molecules26051489
    The leaves of Carica papaya (CP) are rich in natural antioxidants. Carica papaya has traditionally been used to treat various ailments, including skin diseases. This study aims to decipher the antioxidant effects and phytochemical content of different CP leaf extracts (CPEs) obtained using supercritical carbon dioxide (scCO2) and conventional extraction methods. The antioxidant activities of CPEs were evaluated by cell-free (1,1-diphenyl-2-picryl-hydrazyl (DPPH) and ferric-reduced antioxidative power (FRAP)) and cell-based (H2O2) assay. Both C. papaya leaf scCO2 extract with 5% ethanol (CPSCE) and C. papaya leaf scCO2 extract (CPSC) exhibited stronger DPPH radical scavenging activity than conventional extracts. In the FRAP assay, two hydrophilic extracts (C. papaya leaf ethanol extract (CPEE) and C. papaya freeze-dried leaf juice (CPFD)) showed relatively stronger reducing power compared to lipophilic extracts. Cell-based assays showed that CPFD significantly protected skin fibroblasts from H2O2-induced oxidative stress in both pre-and post-treatment. CPEE protected skin fibroblasts from oxidative stress in a dose-dependent manner while CPSCE significantly triggered the fibroblast recovery after treatment with H2O2. GC-MS analysis indicated that CPSCE had the highest α-tocopherol and squalene contents. By contrast, both CP hydrophilic extracts (CPEE and CPFD) had a higher total phenolic content (TPC) and rutin content than the lipophilic extracts. Overall, CPEs extracted using green and conventional extraction methods showed antioxidative potential in both cell-based and cell-free assays due to their lipophilic and hydrophilic antioxidants, respectively.
    Matched MeSH terms: Freeze Drying
  2. Foo PC, Chan YY, See Too WC, Tan ZN, Wong WK, Lalitha P, et al.
    J Med Microbiol, 2012 Sep;61(Pt 9):1219-1225.
    PMID: 22556327 DOI: 10.1099/jmm.0.044552-0
    Entamoeba histolytica is the only Entamoeba species that causes amoebiasis in humans. Approximately 50 million people are infected, with 100, 000 deaths annually in endemic countries. Molecular diagnosis of Entamoeba histolytica is important to differentiate it from the morphologically identical Entamoeba dispar to avoid unnecessary medication. Conventional molecular diagnostic tests require trained personnel, cold-chain transportation and/or are storage-dependent, which make them user-unfriendly. The aim of this study was to develop a thermostabilized, one-step, nested, tetraplex PCR assay for the detection of Entamoeba histolytica, Entamoeba dispar and Entamoeba species in cold-chain-free and ready-to-use form. The PCR test was designed based on the Entamoeba small subunit rRNA (SSU-rRNA) gene, which detects the presence of any Entamoeba species, and simultaneously can be used to differentiate Entamoeba histolytica from Entamoeba dispar. In addition, a pair of primers was designed to serve as an internal amplification control to help identify inhibitors in the samples. All PCR reagents together with the designed primers were thermostabilized by lyophilization and were stable at 24 °C for at least 6 months. The limit of detection of the tetraplex PCR was found to be 39 pg DNA or 1000 cells for Entamoeba histolytica and 78 pg DNA or 1000 cells for Entamoeba dispar, and the specificity was 100 %. In conclusion, this cold-chain-free, thermostabilized, one-step, nested, multiplex PCR assay was found to be efficacious in differentiating Entamoeba histolytica from other non-pathogenic Entamoeba species.
    Matched MeSH terms: Freeze Drying
  3. Mohd Abd Razak MR, Mohmad Misnan N, Md Jelas NH, Norahmad NA, Muhammad A, Ho TCD, et al.
    BMC Complement Altern Med, 2018 Dec 05;18(1):320.
    PMID: 30518360 DOI: 10.1186/s12906-018-2390-7
    BACKGROUND: Carica papaya leaf juice (CPLJ) was well known for its thrombocytosis activity in rodents and dengue patients. However, the effect of CPLJ treatment on other parameters that could contribute to dengue pathogenesis such as nonstructural protein 1 (NS1) production and viremia level have never been highlighted in any clinical and in vivo studies. The aim of this study is to investigate the effect of freeze-dried CPLJ treatment on NS1 and viremia levels of dengue fever mouse model.

    METHODS: The dengue infection in mouse model was established by inoculation of non-mouse adapted New Guinea C strain dengue virus (DEN-2) in AG129 mice. The freeze-dried CPLJ compounds were identified by Ultra-High Performance Liquid Chromatography High Resolution Accurate Mass Spectrometry analysis. The infected AG129 mice were orally treated with 500 mg/kg/day and 1000 mg/kg/day of freeze-dried CPLJ, starting on day 1 post infection for 3 consecutive days. The blood samples were collected from submandibular vein for plasma NS1 assay and quantitation of viral RNA level by quantitative reverse transcription PCR.

    RESULTS: The AG129 mice infected with dengue virus showed marked increase in the production of plasma NS1, which was detectable on day 1 post infection, peaked on day 3 post-infection and started to decline from day 5 post infection. The infection also caused splenomegaly. Twenty-four compounds were identified in the freeze-dried CPLJ. Oral treatment with 500 mg/kg/day and 1000 mg/kg/day of freeze-dried CPLJ did not affect the plasma NS1 and dengue viral RNA levels. However, the morbidity level of infected AG129 mice were slightly decreased when treated with freeze-dried CPLJ.

    CONCLUSION: Oral treatment of 500 mg/kg/day and 1000 mg/kg/day of freeze-dried CPLJ at the onset of viremia did not affect the plasma NS1 and viral RNA levels in AG129 mice infected with non-mouse adapted New Guinea C strain dengue virus.

    Matched MeSH terms: Freeze Drying
  4. Norahmad NA, Mohd Abd Razak MR, Mohmad Misnan N, Md Jelas NH, Sastu UR, Muhammad A, et al.
    BMC Complement Altern Med, 2019 Feb 11;19(1):44.
    PMID: 30744623 DOI: 10.1186/s12906-019-2438-3
    BACKGROUND: Carica papaya leaves have been used for traditional treatment of dengue fever and have been reported to exhibit an immunomodulatory activity by affecting the level of cytokine production in vitro and in vivo. Due to the lack of adequate in vivo evidence in dengue disease model, the present study was initiated to screen and identify the cytokines affected by freeze-dried C. papaya leaf juice (FCPLJ) treatment in AG129 mice infected with DEN-2 dengue virus.

    METHODS: The AG129 mice were fed orally with FCPLJ for 3 consecutive days after 24 h of dengue virus inoculation. Plasma cytokines were screened by using ProcartaPlex immunoassay. The gene expression in the liver was analyzed by using RT2 Profiler PCR Array.

    RESULTS: The results showed that FCPLJ treatment has increased the plasma CCL2/MCP-1 level during peak of viremia. Gene expression study has identified 8 inflammatory cytokine genes which were downregulated in the liver of infected AG129 mice treated with FCPLJ. The downregulated inflammatory cytokine genes were CCL6/MRP-1, CCL8/MCP-2, CCL12/MCP-5, CCL17/TARC, IL1R1, IL1RN/IL1Ra, NAMPT/PBEF1 and PF4/CXCL4.

    CONCLUSION: The findings indicated the possible immunomodulatory role of FCPLJ during dengue virus infection in AG129 mice.

    Matched MeSH terms: Freeze Drying
  5. Nyam KL, Chow CF, Tan CS, Ng ST
    Int J Med Mushrooms, 2017;19(7):607-617.
    PMID: 29199582 DOI: 10.1615/IntJMedMushrooms.2017021186
    Diabetes mellitus is a major cause of morbidity and mortality worldwide. Although scientific evidence supporting its therapeutic efficacy is lacking, the use of the tiger's milk mushroom (TGM; Lignosus rhinocerotis), which is native to tropical areas such as Malaysia, Indonesia, and the Philippines, has been found to contain a very large amount of potential antioxidants. In this study, rats were weighed and then intravenously injected with 35 mg/kg streptozotocin (STZ). Rats were left for 1 week before blood glucose concentrations were measured to determine the onset of diabetes before the next procedure was conducted. Rats with blood glucose exceeding 7.0 mmol/L were considered diabetic and were included in the experiment. All groups were fed their respective treatments twice daily for 2 months throughout the experiment. Antidiabetic and antioxidant properties of freeze-dried TGM powder, such as reduced glutathione (GSH), superoxide dismutase (SOD), lipid peroxidation (LPO), and catalase (CAT) activities, were investigated in liver samples. The biological compounds present in the freeze-dried TGM powder was found to exhibit antidiabetic properties by significantly reducing elevated blood glucose concentrations to a normal range (3.0-7.0 mmol/L) in Sprague-Dawley rats with streptozotocin-induced diabetes, and increasing the body weight of the rats. Freeze-dried TGM powder was also found to possess antioxidant activity by significantly increasing GSH, CAT, and SOD activities while reducing LPO (P < 0.05). THis study shows that freeze-dried TGM powder exhibits significant antidiabetic properties and may be a potential supplement in ameliorating diabetic complications.
    Matched MeSH terms: Freeze Drying
  6. Azman NA, Gordon MH, Skowyra M, Segovia F, Almajano MP
    J Sci Food Agric, 2015 Jul;95(9):1804-11.
    PMID: 25139796 DOI: 10.1002/jsfa.6878
    Gentiana lutea root is a medicinal herb that contains many active compounds which contribute to physiological effects, and it has recently attracted much attention as a natural source of antioxidants. The aim of this study was to evaluate the effects on the colour, pH, microbial activities, sensory quality and resistance to lipid oxidation (through the thiobarbituric acid method) during storage of beef patties containing different concentrations of G. lutea. Fresh beef patties were formulated with 0-5 g kg(-1) of G. lutea and 0 or 0.5 g kg(-1) of ascorbic acid and packed in two different atmospheres, Modified Atmosphere 1 (MAP1) and Modified Atmosphere 2 (MAP2), and stored at 4 ± 1 °C for 10 days. MAP1 contained 20:80 (v/v) O2:CO2 and MAP2 contained 80:20 (v/v) O2:CO2.
    Matched MeSH terms: Freeze Drying
  7. Mediani A, Abas F, Khatib A, Tan CP, Ismail IS, Shaari K, et al.
    Plant Foods Hum Nutr, 2015 Jun;70(2):184-92.
    PMID: 25800644 DOI: 10.1007/s11130-015-0478-5
    The study investigated the changes in the metabolite, antioxidant and α-glucosidase inhibitory activities of Phyllanthus niruri after three drying treatments: air, freeze and oven dryings. Water extracts and extracts obtained using different solvent ratios of ethanol and methanol (50, 70, 80 and 100%) were compared. The relationships among the antioxidant, α-glucosidase inhibitory activity and metabolite levels of the extracts were evaluated using partial least-square analysis (PLS). The solvent selectivity was assessed based on the phytochemical constituents present in the extract and their concentrations quantitatively analyzed using high performance liquid chromatography. The freeze-dried P. niruri samples that were extracted with the mixture of ethanol or methanol with low ratio of water showed higher biological activity values compared with the other extracts. The PLS results for the ethanolic with different ratio and water extracts demonstrated that phenolic acids (chlorogenic acid and ellagic acid) and flavonoids were highly linked to strong α-glucosidase inhibitory and antioxidant activities.
    Matched MeSH terms: Freeze Drying
  8. Ngah NA, Dias GJ, Tong DC, Mohd Noor SNF, Ratnayake J, Cooper PR, et al.
    Molecules, 2021 Nov 25;26(23).
    PMID: 34885714 DOI: 10.3390/molecules26237131
    BACKGROUND: Platelet-rich fibrin (PRF) has gained popularity in craniofacial surgery, as it provides an excellent reservoir of autologous growth factors (GFs) that are essential for bone regeneration. However, the low elastic modulus, short-term clinical application, poor storage potential and limitations in emergency therapy use restrict its more widespread clinical application. This study fabricates lyophilised PRF (Ly-PRF), evaluates its physical and biological properties, and explores its application for craniofacial tissue engineering purposes.

    MATERIAL AND METHODS: A lyophilisation method was applied, and the outcome was evaluated and compared with traditionally prepared PRF. We investigated how lyophilisation affected PRF's physical characteristics and biological properties by determining: (1) the physical and morphological architecture of Ly-PRF using SEM, and (2) the kinetic release of PDGF-AB using ELISA.

    RESULTS: Ly-PRF exhibited a dense and homogeneous interconnected 3D fibrin network. Moreover, clusters of morphologically consistent cells of platelets and leukocytes were apparent within Ly-PRF, along with evidence of PDGF-AB release in accordance with previously reports.

    CONCLUSIONS: The protocol established in this study for Ly-PRF preparation demonstrated versatility, and provides a biomaterial with growth factor release for potential use as a craniofacial bioscaffold.

    Matched MeSH terms: Freeze Drying
  9. Liew KB, Peh KK
    Arch Pharm Res, 2021 Aug;44(8):1-10.
    PMID: 25579848 DOI: 10.1007/s12272-014-0542-y
    Orally disintegrating tablet (ODT) is a user friendly and convenient dosage form. The study aimed to investigate the effect of polymers and wheat starch on the tablet properties of lyophilized ODT, with dapoxetine as model drug. Three polymers (hydroxypropylmethyl cellulose, carbopol 934P and Eudragit® EPO) and wheat starch were used as matrix forming materials in preparation of lyophilized ODT. The polymeric dispersion was casted into a mould and kept in a freezer at -20 °C for 4 h before freeze dried for 12 h. It was found that increasing in HPMC and Carbopol 934P concentrations produced tablets with higher hardness and longer disintegration time. In contrast, Eudragit® EPO was unable to form tablet with sufficient hardness at various concentrations. Moreover, HPMC seems to have a stronger effect on tablet hardness compared to Carbopol 934P at the same concentration level. ODT of less friable was obtained. Wheat starch acted as binder which strengthen the hardness of ODTs and prolonged the disintegration time. ODT comprising of HPMC and wheat starch at ratio of 2:1 was found to be optimum based upon the tablet properties. The optimum formulation was palatable and 80 % of the drug was released within 30 min in the dissolution study.
    Matched MeSH terms: Freeze Drying
  10. Hajeb P, Jinap S, Shakibazadeh Sh, Afsah-Hejri L, Mohebbi GH, Zaidul IS
    PMID: 25090228 DOI: 10.1080/19440049.2014.942707
    This study aims to optimise the operating conditions for the supercritical fluid extraction (SFE) of toxic elements from fish oil. The SFE operating parameters of pressure, temperature, CO2 flow rate and extraction time were optimised using a central composite design (CCD) of response surface methodology (RSM). High coefficients of determination (R²) (0.897-0.988) for the predicted response surface models confirmed a satisfactory adjustment of the polynomial regression models with the operation conditions. The results showed that the linear and quadratic terms of pressure and temperature were the most significant (p < 0.05) variables affecting the overall responses. The optimum conditions for the simultaneous elimination of toxic elements comprised a pressure of 61 MPa, a temperature of 39.8ºC, a CO₂ flow rate of 3.7 ml min⁻¹ and an extraction time of 4 h. These optimised SFE conditions were able to produce fish oil with the contents of lead, cadmium, arsenic and mercury reduced by up to 98.3%, 96.1%, 94.9% and 93.7%, respectively. The fish oil extracted under the optimised SFE operating conditions was of good quality in terms of its fatty acid constituents.
    Matched MeSH terms: Freeze Drying
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