Displaying publications 81 - 100 of 103 in total

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  1. Production of biodiesel by lipase-catalyzed transesterification of vegetable oils: a kinetics study
    Al-Zuhair S
    Biotechnol Prog, 2005 Sep-Oct;21(5):1442-8.
    PMID: 16209548
    Kinetics of production of biodiesel by enzymatic methanolysis of vegetable oils using lipase has been investigated. A mathematical model taking into account the mechanism of the methanolysis reaction starting from the vegetable oil as substrate, rather than the free fatty acids, has been developed. The kinetic parameters were estimated by fitting the experimental data of the enzymatic reaction of sunflower oil by two types of lipases, namely, Rhizomucor miehei lipase (RM) immobilized on ion-exchange resins and Thermomyces lanuginosa lipase (TL) immobilized on silica gel. There was a good agreement between the experimental results of the initial rate of reaction and those predicted by the proposed model equations, for both enzymes. From the proposed model equations, the regions where the effect of alcohol inhibition fades, at different substrate concentrations, were identified. The proposed model equation can be used to predict the rate of methanolysis of vegetable oils in a batch or a continuous reactor and to determine the optimal conditions for biodiesel production.
    Matched MeSH terms: Enzyme Activation
  2. Lipase-catalyzed esterification of palm-based 9,10-dihydroxystearic acid and 1-octanol in hexane--a kinetic study
    Awang R, Basri M, Ahmad S, Salleh AB
    Biotechnol Lett, 2004 Jan;26(1):11-4.
    PMID: 15005144
    The esterification of palm-based 9,10-dihydroxystearic acid (DHSA) and 1-octanol in hexane as catalyzed by lipase from Rhizomucor meihei (Lipozyme IM) followed Michaelis-Menten kinetics. The esterification reaction follows a Ping-Pong, Bi-Bi mechanism. The maximum rate was estimated to be 1 micromol min(-1) mg(-1) catalyst in hexane at 50 degrees C, and the Michaelis-Menten constants for DHSA and 1-octanol were 1.3 M and 0.7 M, respectively.
    Matched MeSH terms: Enzyme Activation
  3. Kinetics based reaction optimization of enzyme catalyzed reduction of formaldehyde to methanol with synchronous cofactor regeneration
    Marpani F, Sárossy Z, Pinelo M, Meyer AS
    Biotechnol Bioeng, 2017 12;114(12):2762-2770.
    PMID: 28832942 DOI: 10.1002/bit.26405
    Enzymatic reduction of carbon dioxide (CO2 ) to methanol (CH3 OH) can be accomplished using a designed set-up of three oxidoreductases utilizing reduced pyridine nucleotide (NADH) as cofactor for the reducing equivalents electron supply. For this enzyme system to function efficiently a balanced regeneration of the reducing equivalents during reaction is required. Herein, we report the optimization of the enzymatic conversion of formaldehyde (CHOH) to CH3 OH by alcohol dehydrogenase, the final step of the enzymatic redox reaction of CO2 to CH3 OH, with kinetically synchronous enzymatic cofactor regeneration using either glucose dehydrogenase (System I) or xylose dehydrogenase (System II). A mathematical model of the enzyme kinetics was employed to identify the best reaction set-up for attaining optimal cofactor recycling rate and enzyme utilization efficiency. Targeted process optimization experiments were conducted to verify the kinetically modeled results. Repetitive reaction cycles were shown to enhance the yield of CH3 OH, increase the total turnover number (TTN) and the biocatalytic productivity rate (BPR) value for both system I and II whilst minimizing the exposure of the enzymes to high concentrations of CHOH. System II was found to be superior to System I with a yield of 8 mM CH3 OH, a TTN of 160 and BPR of 24 μmol CH3 OH/U · h during 6 hr of reaction. The study demonstrates that an optimal reaction set-up could be designed from rational kinetics modeling to maximize the yield of CH3 OH, whilst simultaneously optimizing cofactor recycling and enzyme utilization efficiency.
    Matched MeSH terms: Enzyme Activation
  4. Physical factors affecting the production of organic solvent-tolerant protease by Pseudomonas aeruginosa strain K
    Rahman RN, Geok LP, Basri M, Salleh AB
    Bioresour Technol, 2005 Mar;96(4):429-36.
    PMID: 15491823
    The physical factors affecting the production of an organic solvent-tolerant protease from Pseudomonas aeruginosa strain K was investigated. Growth and protease production were detected from 37 to 45 degrees C with 37 degrees C being the optimum temperature for P. aeruginosa. Maximum enzyme activity was achieved at static conditions with 4.0% (v/v) inoculum. Shifting the culture from stationary to shaking condition decreased the protease production (6.0-10.0% v/v). Extracellular organic solvent-tolerant protease was detected over a broad pH range from 6.0 to 9.0. However, the highest yield of protease was observed at pH 7.0. Neutral media increased the protease production compared to acidic or alkaline media.
    Matched MeSH terms: Enzyme Activation
  5. Studies of reaction parameters on synthesis of Citronellyl laurate ester via immobilized Candida rugosa lipase in organic media
    Serri NA, Kamaruddin AH, Long WS
    Bioprocess Biosyst Eng, 2006 Oct;29(4):253-60.
    PMID: 16868763
    Immobilized Candida rugosa lipase was used for the synthesis of citronellyl laurate from citronellol and lauric acid. Screening of different types of support (Amberlite MB-1 and Celite) for immobilization of lipase and solvent (n-hexane, n-heptane, and iso-octane) and optimization of reaction conditions, such as catalyst loading, effect of substrates molar ratio and temperature, have been studied. The maximum enzyme activity was obtained at 310 K. The immobilized C. rugosa lipase onto Amberlite MB-1 support was found to be the best support with a conversion of 89% of citronellyl laurate ester in iso-octane compared to Celite 545. Deactivation of C. rugosa lipase at 313, 318 and 323 K were observed. Ordered bi bi mechanism with dead end complex of lauric acid was found to fit the initial rate data and the kinetic parameters were obtained by non-linear regression analysis.
    Matched MeSH terms: Enzyme Activation
  6. Synthesis and cholinesterase inhibitory activity study of new piperidone grafted spiropyrrolidines
    Basiri A, Abd Razik BM, Ezzat MO, Kia Y, Kumar RS, Almansour AI, et al.
    Bioorg Chem, 2017 12;75:210-216.
    PMID: 28987876 DOI: 10.1016/j.bioorg.2017.09.019
    Alzheimer's disease (AD) is a prevalent neurodegenerative disorder, which affected 35 million people in the world. The most practiced approach to improve the life expectancy of AD patients is to increase acetylcholine neurotransmitter level at cholinergic synapses by inhibition of cholinesterase enzymes. A series of unreported piperidone grafted spiropyrrolidines 8(a-p) were synthesized and evaluated in vitro for their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities. Therein, compounds 8h and 8l displayed more potent AChE enzyme inhibition than standard drug with IC50 values of 1.88 and 1.37 µM, respectively. Molecular docking simulations for 8l possessing the most potent AChE inhibitory activities, disclosed its interesting binding templates to the active site channel of AChE enzymes. These compounds are remarkable AChE inhibitors and have potential as AD drugs.
    Matched MeSH terms: Enzyme Activation/drug effects
  7. One-pot microwave assisted stereoselective synthesis of novel dihydro-2'H-spiro[indene-2,1'-pyrrolo-[3,4-c]pyrrole]-tetraones and evaluation of their antimycobacterial activity and inhibition of AChE
    Bharkavi C, Vivek Kumar S, Ashraf Ali M, Osman H, Muthusubramanian S, Perumal S
    Bioorg Med Chem Lett, 2017 Jul 15;27(14):3071-3075.
    PMID: 28552337 DOI: 10.1016/j.bmcl.2017.05.050
    An efficient one-pot microwave assisted stereoselective synthesis of novel dihydro-2'H-spiro[indene-2,1'-pyrrolo[3,4-c]pyrrole]-tetraone derivatives through three-component 1,3-dipolar cycloaddition of azomethine ylides generated in situ from ninhydrin and sarcosine with a series of 1-aryl-1H-pyrrole-2,5-diones is described. The synthesised compounds were screened for their antimycobacterial and AChE inhibition activities. Compound 4b (IC50 1.30µM) has been found to display twelve fold antimycobacterial activity compared to cycloserine and it is thirty seven times more active than pyrimethamine. Compound 4h displays maximum AchE inhibitory activity with IC50 value of 0.78±0.01µmol/L.
    Matched MeSH terms: Enzyme Activation/drug effects
  8. Synthesis of novel derivatives of oxindole, their urease inhibition and molecular docking studies
    Taha M, Ismail NH, Khan A, Shah SA, Anwar A, Halim SA, et al.
    Bioorg Med Chem Lett, 2015 Aug 15;25(16):3285-9.
    PMID: 26077497 DOI: 10.1016/j.bmcl.2015.05.069
    We synthesized a series of novel 5-24 derivatives of oxindole. The synthesis started from 5-chlorooxindole, which was condensed with methyl 4-carboxybezoate and result in the formation of benzolyester derivatives of oxindole which was then treated with hydrazine hydrate. The oxindole benzoylhydrazide was treated with aryl acetophenones and aldehydes to get target compounds 5-24. The synthesized compounds were evaluated for urease inhibition; the compound 5 (IC50 = 13.00 ± 0.35 μM) and 11 (IC50 = 19.20 ± 0.50 μM) showed potent activity as compared to the standard drug thiourea (IC50 = 21.00 ± 0.01 μM). Other compounds showed moderate to weak activity. All synthetic compounds were characterized by different spectroscopic techniques including (1)H NMR, (13)C NMR, IR and EI MS. The molecular interactions of the active compounds within the binding site of urease enzyme were studied through molecular docking simulations.
    Matched MeSH terms: Enzyme Activation/drug effects
  9. Fulltext Arctium lappa L. root extract induces cell death via mitochondrial-mediated caspase-dependent apoptosis in Jurkat human leukemic T cells
    Gurunanselage Don RAS, Yap MKK
    Biomed Pharmacother, 2019 Feb;110:918-929.
    PMID: 30572196 DOI: 10.1016/j.biopha.2018.12.023
    Arctium lappa L. is a perennial herb traditionally consumed to improve well-being. It has been widely reported for its antioxidant properties; however, very little is known for its exact mechanisms underlying the anticancer activity. This study aimed to investigate the mechanisms of anticancer action for different A. lappa root extracts. Arctium lappa root was extracted with ethanol, hexane and ethyl acetate, then examined for in vitro anticancer activity against cancerous HeLa, MCF-7, Jurkat cell lines and non-cancerous 3T3 cell lines. Induction of apoptosis was determined by cellular morphological changes, mitochondrial membrane potential (ΔΨm), caspase-3/7 activity and DNA fragmentation. The active compounds present in the most potent root extracts were identified by LC-ESI-MS. Among all the extracts, ethyl acetate root extract has the highest potency with IC50 of 102.2 ± 42.4 μg/ml, followed by ethanolic root extract in Jurkat T cells, at 24 h. None of the extracts were cytotoxic against 3T3 cells, suggesting that the extracts were selective against cancerous cells only. Both ethyl acetate and ethanolic root extracts exhibited significant morphological changes in Jurkat T cells, including the detachment from adjacent cells, appearance of apoptotic bodies and cells shrinkage. The extracts treated cells also displayed an increase in caspase-3/7 activity and alteration in mitochondrial membrane potential. Only ethyl acetate root extract at IC50 induced DNA fragmentation in Jurkat T cells. LC-ESI-MS analysis of the extract revealed the presence of 8 compounds, of which only 6 compounds with various biological activities reported. These findings suggest that the ethyl acetate extract of A. lappa had strong anticancer potential and induced intrinsic apoptosis via loss of ΔΨm and activation of caspase-3/7 This study can provide new insight to the discovery of new promising lead compound in chemopreventive and chemotherapeutic strategies.
    Matched MeSH terms: Enzyme Activation/drug effects; Enzyme Activation/physiology
  10. Effects of iridoids on lipoxygenase and hyaluronidase activities and their activation by beta-glucosidase in the presence of amino acids
    Ling SK, Tanaka T, Kouno I
    Biol Pharm Bull, 2003 Mar;26(3):352-6.
    PMID: 12612446
    Enzyme inhibitory activities of 14 iridoids previously obtained from two Malaysian medicinal plants, Saprosma scortechinii and Rothmannia macrophylla, were evaluated in vitro using soybean lipoxygenase and bovine testis hyaluronidase. Most of the iridoids, including asperulosidic acid, paederosidic acid, and an epimeric mixture of gardenogenins A and B, did not show any effect on the enzyme activities, except for the bis-iridoids, which inhibited the lipoxygenase activity with their IC(50) values of approximately 1.3 times that of a known inhibitor, fisetin. Structural modification of asperulosidic acid and paederosidic acid through enzymatic hydrolysis by beta-glucosidase resulted in their inhibition towards the enzyme activities, and these activities were enhanced by the presence of some amino acids (lysine, leucine or glutamic acid) or ammonium acetate. Mixtures of gardenogenins A and B; isomers of non-glucosidic iridoids, incubated with amino acid or ammonium acetate did not show any inhibitory effect on the enzyme activities during the 6 h incubation period, except for lysine where spontaneous reaction between the iridoids and amino acid resulted in the inhibition of lipoxygenase activity. The results from these biomimetic reactions suggested that the iridoid aglycons and the intermediates formed by these reactive species could inhibit the enzyme activities, and thus substantiate previous reports that the formation of iridoidal aglycons is a prerequisite for the iridoid glycosides to demonstrate some of the biological activities. In addition, the results also indicated that it is worthwhile to further explore these intermediates as potential anti-inflammatory agents.
    Matched MeSH terms: Enzyme Activation/drug effects
  11. The activation of chick alkaline phosphatase by calmodulin
    Sivanaesan L, Kwan TK, Perumal R
    Biochem. Int., 1991 Oct;25(3):561-70.
    PMID: 1666829
    Calmodulin, an activator protein in most calcium-dependent processes, was isolated to apparent homogeneity from the femurs of 1-day old chicks using phenyl-Sepharose and high performance liquid chromatography. The purified calmodulin was found to produce a 6-fold increase in the activity of alkaline phosphatase isolated from the same source. A Ca2+ concentration of 10(-5) M was required for the activation. Purification of alkaline phosphatase involved acetone precipitation, DEAE-Sephacel and Sephadex G-200 column chromatography. The enzyme was purified to 540-fold and had a specific activity of 10.75 U/mg protein.
    Matched MeSH terms: Enzyme Activation/physiology
  12. Fulltext An expedient synthesis, acetylcholinesterase inhibitory activity, and molecular modeling study of highly functionalized hexahydro-1,6-naphthyridines
    Almansour AI, Kumar RS, Arumugam N, Basiri A, Kia Y, Ali MA
    Biomed Res Int, 2015;2015:965987.
    PMID: 25710037 DOI: 10.1155/2015/965987
    A series of hexahydro-1,6-naphthyridines were synthesized in good yields by the reaction of 3,5-bis[(E)-arylmethylidene]tetrahydro-4(1H)-pyridinones with cyanoacetamide in the presence of sodium ethoxide under simple mixing at ambient temperature for 6-10 minutes and were assayed for their acetylcholinesterase (AChE) inhibitory activity using colorimetric Ellman's method. Compound 4e with methoxy substituent at ortho-position of the phenyl rings displayed the maximum inhibitory activity with IC50 value of 2.12 μM. Molecular modeling simulation of 4e was performed using three-dimensional structure of Torpedo californica AChE (TcAChE) enzyme to disclose binding interaction and orientation of this molecule into the active site gorge of the receptor.
    Matched MeSH terms: Enzyme Activation
  13. Fulltext Purification and characterization of alkaline-thermostable protease enzyme from Pitaya (Hylocereus polyrhizus) waste: a potential low cost of the enzyme
    Amid M, Manap MY, Zohdi NK
    Biomed Res Int, 2014;2014:259238.
    PMID: 25328883 DOI: 10.1155/2014/259238
    The thermoalkaline protease enzyme from pitaya (Hylocereus polyrhizus) waste was purified by a factor of 221.2 with 71.3% recovery using ammonium sulphate precipitation, gel filtration, and cation exchange chromatography. Gel filtration chromatography together with sodium dodecyl sulphate gel electrophoresis (SDS-PAGE) revealed that the enzyme is monomeric with a molecular weight of 26.7 kDa. The apparent K m and V max of the protease were 2.8 mg/mL and 31.20 u/min, respectively. The optimum pH and temperature were 8.0 and 70°C. The enzyme was highly active and stable over a wide pH range (from pH 3.0 to pH 11.0 with the optimum activity at pH 8.0). The protease has broad specificity toward azocasein, casein, hemoglobin, and gelatine. Activity of the enzyme was inhibited by Fe(2+) and Zn(2+), while protease activity was increased in the presence of Ca(2+) and Mg(2+) and Cu(2+) by factors of 125%, 110%, and 105%, respectively. The alkaline protease showed extreme stability toward surfactants and oxidizing agent. The purified protease exhibited extreme stability in the presence of organic solvents and inhibitors. In addition, the enzyme was relativity stable toward organic solvents and chelating agents, such as ethylenediaminetetraacetic acid (EDTA). The enzyme, derived from pitaya peel, possesses unique characteristics and could be used in various industrial and biotechnological applications.
    Matched MeSH terms: Enzyme Activation
  14. Fulltext Heterologous, Expression, and Characterization of Thermostable Glucoamylase Derived from Aspergillus flavus NSH9 in Pichia pastoris
    Karim KM, Husaini A, Hossain MA, Sing NN, Mohd Sinang F, Hussain MH, et al.
    Biomed Res Int, 2016;2016:5962028.
    PMID: 27504454 DOI: 10.1155/2016/5962028
    A novel thermostable glucoamylase cDNA without starch binding domain (SBD) of Aspergillus flavus NSH9 was successfully identified, isolated, and overexpressed in Pichia pastoris GS115. The complete open reading frame of glucoamylase from Aspergillus flavus NSH9 was identified by employing PCR that encodes 493 amino acids lacking in the SBD. The first 17 amino acids were presumed to be a signal peptide. The cDNA was cloned into Pichia pastoris and the highest expression of recombinant glucoamylase (rGA) was observed after 8 days of incubation period with 1% methanol. The molecular weight of the purified rGA was about 78 kDa and exhibited optimum catalytic activity at pH 5.0 and temperature of 70°C. The enzyme was stable at higher temperature with 50% of residual activity observed after 20 min at 90°C and 100°C. Low concentration of metal (Mg(++), Fe(++), Zn(++), Cu(++), and Pb(++)) had positive effect on rGA activity. This rGA has the potential for use and application in the saccharification steps, due to its thermostability, in the starch processing industries.
    Matched MeSH terms: Enzyme Activation
  15. Fulltext Zerumbone-induced antinociception: involvement of the L-arginine-nitric oxide-cGMP -PKC-K+ ATP channel pathways
    Perimal EK, Akhtar MN, Mohamad AS, Khalid MH, Ming OH, Khalid S, et al.
    Basic Clin Pharmacol Toxicol, 2011 Mar;108(3):155-62.
    PMID: 20955360 DOI: 10.1111/j.1742-7843.2010.00635.x
    This study investigated the antinociceptive effects of zerumbone in chemical behavioural models of nociception in mice. Zerumbone given through intraperitoneal route (i.p.) produced dose-related antinociception when assessed on acetic acid-induced abdominal writhing test in mice. In addition, the i.p. administration of zerumbone exhibited significant inhibition of the neurogenic pain induced by intraplantar (i.pl.) injection of capsaicin and bradykinin. Likewise, zerumbone given by i.p. route reduced the nociception produced by i.pl. injection of glutamate and phorbol myristate acetate (PMA). The antinociception caused by zerumbone in the acetic acid test was significantly attenuated by i.p. pre-treatment of mice with l-arginine (nitric oxide precursor) and glibenclamide (ATP-sensitive K(+) channel inhibitor). However, the antinociception of zerumbone was enhanced by methylene blue (non-specific gyanylyl cyclase inhibitor). Together, these results indicate that zerumbone produces pronounced antinociception against chemical models of nociception in mice. It also strongly suggests that the l-arginine-nitric oxide-cGMP-PKC-K(+) ATP channel pathways, the TRPV1 and kinin B2 receptors play an important role in the zerumbone-induced antinociception.
    Matched MeSH terms: Enzyme Activation/drug effects
  16. Fulltext Genome wide transcriptome profiling of a murine acute melioidosis model reveals new insights into how Burkholderia pseudomallei overcomes host innate immunity
    Chin CY, Monack DM, Nathan S
    BMC Genomics, 2010;11:672.
    PMID: 21110886 DOI: 10.1186/1471-2164-11-672
    At present, very little is known about how Burkholderia pseudomallei (B. pseudomallei) interacts with its host to elicit melioidosis symptoms. We established a murine acute-phase melioidosis model and used DNA microarray technology to investigate the global host/pathogen interaction. We compared the transcriptome of infected liver and spleen with uninfected tissues over an infection period of 42 hr to identify genes whose expression is altered in response to an acute infection.
    Matched MeSH terms: Enzyme Activation
  17. Fulltext Functional expression of a novel α-amylase from Antarctic psychrotolerant fungus for baking industry and its magnetic immobilization
    He L, Mao Y, Zhang L, Wang H, Alias SA, Gao B, et al.
    BMC Biotechnol, 2017 02 28;17(1):22.
    PMID: 28245836 DOI: 10.1186/s12896-017-0343-8
    BACKGROUND: α-Amylase plays a pivotal role in a broad range of industrial processes. To meet increasing demands of biocatalytic tasks, considerable efforts have been made to isolate enzymes produced by extremophiles. However, the relevant data of α-amylases from cold-adapted fungi are still insufficient. In addition, bread quality presents a particular interest due to its high consummation. Thus developing amylases to improve textural properties could combine health benefits with good sensory properties. Furthermore, iron oxide nanoparticles provide an economical and convenient method for separation of biomacromolecules. In order to maximize the catalytic efficiency of α-amylase and support further applications, a comprehensive characterization of magnetic immobilization of α-amylase is crucial and needed.

    RESULTS: A novel α-amylase (AmyA1) containing an open reading frame of 1482 bp was cloned from Antarctic psychrotolerant fungus G. pannorum and then expressed in the newly constructed Aspergillus oryzae system. The purified recombinant AmyA1 was approximate 52 kDa. AmyA1 was optimally active at pH 5.0 and 40 °C, and retained over 20% of maximal activity at 0-20 °C. The K m and V max values toward soluble starch were 2.51 mg/mL and 8.24 × 10-2 mg/(mL min) respectively, with specific activity of 12.8 × 103 U/mg. AmyA1 presented broad substrate specificity, and the main hydrolysis products were glucose, maltose, and maltotetraose. The influence of AmyA1 on the quality of bread was further investigated. The application study shows a 26% increase in specific volume, 14.5% increase in cohesiveness and 14.1% decrease in gumminess in comparison with the control. AmyA1 was immobilized on magnetic nanoparticles and characterized. The immobilized enzyme showed improved thermostability and enhanced pH tolerance under neutral conditions. Also, magnetically immobilized AmyA1 can be easily recovered and reused for maximum utilization.

    CONCLUSIONS: A novel α-amylase (AmyA1) from Antarctic psychrotolerant fungus was cloned, heterologous expression in Aspergillus oryzae, and characterized. The detailed report of the enzymatic properties of AmyA1 gives new insights into fungal cold-adapted amylase. Application study showed potential value of AmyA1 in the food and starch fields. In addition, AmyA1 was immobilized on magnetic nanoparticles and characterized. The improved stability and longer service life of AmyA1 could potentially benefit industrial applications.

    Matched MeSH terms: Enzyme Activation
  18. Effects of tocotrienols on cell viability and apoptosis in normal murine liver cells (BNL CL.2) and liver cancer cells (BNL 1ME A.7R.1), in vitro
    Har CH, Keong CK
    Asia Pac J Clin Nutr, 2005;14(4):374-80.
    PMID: 16326644
    The effects of tocotrienols on murine liver cell viability and their apoptotic events were studied over a dose range of 0-32 microg mL(-1). Normal murine liver cells (BNL CL.2) and murine liver cancer cells (BNL 1ME A.7R.1) were treated with tocotrienols (T(3)), alpha tocopherol (alpha-T) and the chemo drug, Doxorubicin (Doxo, as a positive control). Cell viability assay showed that T(3) significantly (P < or = 0.05) lowered the percentage of BNL 1ME A.7R.1 cell viability in a dose-responsive manner (8-16 microg mL(-1)), whereas T did not show any significant (P>0.05) inhibition in cell viability with increasing treatment doses of 0-16 microg mL(-1). The IC(50) for tocotrienols were 9.8, 8.9, 8.1, 9.7, 8.1 and 9.3 microg mL(-1) at 12, 24, 36, 48, 60 and 72 hours respectively. Early apoptosis was detected 6 hours following T(3) treatment of BNL 1ME A.7R.1 liver cancer cells, using Annexin V-FITC fluorescence microscopy assay for apoptosis, but none were observed for the non-treated liver cancer cells at the average IC(50) of 8.98 microg mL(-1) tocotrienols for liver cancer cells. Several apoptotic bodies were detected in BNL 1ME A.7R.1 liver cancer cells at 6 hours post-treatment with tocotrienols (8.98 microg mL(-1)) using Acridine Orange/Propidium Iodide fluorescence assay. However, only a couple of apoptotic bodies were seen in the non-treated liver cancer cells and the BNL CL.2 normal liver cells. Some mitotic bodies were also observed in the T(3)-treated BNL 1ME A.7R.1 liver cancer cells but were not seen in the untreated BNL 1ME A.7R.1 cells and the BNL CL.2 liver cells. Following T(3)-treatment (8.98 microg mL(-1)) of the BNL 1ME A.7R.1 liver cancer cells, 24.62%, 25.53% and 44.90% of the cells showed elevated active caspase 3 activity at 9, 12 and 24 hours treatment period, respectively. DNA laddering studies indicated DNA fragmentation occurred in the T(3)-treated liver cancer cells, BNL 1ME A.7R.1 but not in non-treated liver cancer cells and the T(3)-treated and non-treated normal liver cells. These results suggest that tocotrienols were able to reduce the cell viability in the murine liver cancer cells at a dose of 8-32 microg mL(-1) and that this decrease in percentage cell viability may be due to apoptosis.
    Matched MeSH terms: Enzyme Activation
  19. Rabdosia rubescens Linn: green synthesis of gold nanoparticles and their anticancer effects against human lung cancer cells A549
    Zhang X, Tan Z, Jia K, Zhang W, Dang M
    Artif Cells Nanomed Biotechnol, 2019 Dec;47(1):2171-2178.
    PMID: 31159596 DOI: 10.1080/21691401.2019.1620249
    Nanomedicine is a rapidly emerging field and is reported to be a promising tool for treating various diseases. Green synthesized nanoparticles are documented to possess a potent anticancer effect. Rabdosia rubescens is a Chinese plant which is also one of the components of PC-SPES and used to treat prostate cancer. In the present study, we synthesized the gold nanoparticles from R. rubescens (RR-AuNP) and analyzed its anticancer activity against the lung carcinoma A549 cell lines. Since lung cancer is reported to be with increased morbidity and decreased survival rate. The biosynthesized RR-AuNP were confirmed using UV-Visible spectrophotometer, size and shape of RR-AuNP were assessed by DLS, TEM and EDX. The biomolecules present in RR-AuNP and its topographical structure were detected using FTIR, SAED and AFM analysis. MTT assay was performed to detect the IC50 dose of RR-AuNP and its apoptotic effect was assessed by detecting the caspases activation, ROS generation. The anticancer effect of RR-AuNP was confirmed by DAPI staining, TUNEL assay and its molecular mechanism were confirmed by assessing the apoptotic signalling molecules protein expression. Our results illustrate that RR-AuNP showed a strong absorption peak at 550 nm and the RRAuNP were polydispersed nanospheres with size of 130 nm. RR-AuNP IC50 dose against A549 lung carcinoma cell line was detected to be at 25 µg/ml. The results of DAPI staining, TUNEL and immunoblotting analysis confirms both the 25 µg/ml and 50 µg/ml of RR-AuNP possess potent anticancer and apoptotic effect, suggesting that RR-AuNP that it may be a persuasive molecule to treat lung cancer.
    Matched MeSH terms: Enzyme Activation/drug effects
  20. Catalase and superoxide dismutase activities and the total protein content of protocorm-like bodies of Dendrobium sonia-28 subjected to vitrification
    Poobathy R, Sinniah UR, Xavier R, Subramaniam S
    Appl Biochem Biotechnol, 2013 Jul;170(5):1066-79.
    PMID: 23640259 DOI: 10.1007/s12010-013-0241-z
    Dendrobium sonia-28 is an important ornamental orchid in the Malaysian flower industry. However, the genus faces both low germination rates and the risk of producing heterozygous progenies. Cryopreservation is currently the favoured long-term storage method for orchids with propagation problems. Vitrification, a frequently used cryopreservation technique, involves the application of pretreatments and cryoprotectants to protect and recover explants during and after storage in liquid nitrogen. However, cryopreservation may cause osmotic injuries and toxicity to cryopreserved explants from the use of highly concentrated additives, and cellular injuries from thawing, devitrification and ice formation. Reactive oxygen species (ROS), occurring during dehydration and cryopreservation, may also cause membrane damage. Plants possess efficient antioxidant systems such as the superoxide dismutase (SOD) and catalase (CAT) enzymes to scavenge ROS during low temperature stress. In this study, protocorm-like bodies (PLBs) of Dendrobium sonia-28 were assayed for the total protein content, and both SOD and CAT activities, at each stage of a vitrification exercise to observe for deleterious stages in the protocol. The results indicated that cryopreserved PLBs of Dendrobium sonia-28 underwent excessive post-thawing oxidative stress due to decreased levels of the CAT enzyme at the post-thawing recovery stage, which contributed to the poor survival rates of the cryopreserved PLBs.
    Matched MeSH terms: Enzyme Activation
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