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  1. Burkholderia pseudomallei: in vitro susceptibility to some new and old antimicrobials
    Karunakaran R, Puthucheary SD
    Scand. J. Infect. Dis., 2007;39(10):858-61.
    PMID: 17852912
    The treatment of melioidosis currently involves the use of antimicrobials such as ceftazidime, trimethoprim-sulfamethoxazole, amoxicillin-clavulanate and doxycycline. Evaluation of other antimicrobials with activity against the organism continues to be pursued, however, as the causative organism, B. pseudomallei, may not always be susceptible to the above antimicrobials. This study aimed to test the susceptibility of Malaysian isolates of B. pseudomallei against imipenem, meropenem, ertapenem, moxifloxacin and azithromycin. 80 previously stocked clinical isolates collected between 1978 and 2003 from the UMMC, Kuala Lumpur were tested for in vitro susceptibility to these antimicrobials using the E-test minimum inhibitory concentration method. 100% of isolates were sensitive to imipenem and meropenem, 97.5% were sensitive to trimethoprim-sulfamethozaxole, 37.5% to moxifloxacin, and only a minority was sensitive to ertapenem (7.5%). Using breakpoints for Staphylococcus and Haemophilus, 5.0%-6.3% of isolates were sensitive to azithromycin. In conclusion, our findings support the in vitro efficacy of imipenem, meropenem and trimethoprim-sulfamethoxazole against B. pseudomallei. Moxifloxacin, ertapenem and azithromycin cannot be recommended for the treatment of melioidosis; however, further studies are needed to test the efficacy of azithromycin in combination with quinolones.
    Matched MeSH terms: Anti-Bacterial Agents/pharmacology*; Thienamycins/pharmacology*; Imipenem/pharmacology*; Trimethoprim, Sulfamethoxazole Drug Combination/pharmacology*
  2. Hexavalent chromium reduction by Acinetobacter haemolyticus isolated from heavy-metal contaminated wastewater
    Zakaria ZA, Zakaria Z, Surif S, Ahmad WA
    J Hazard Mater, 2007 Jul 19;146(1-2):30-8.
    PMID: 17188812
    Possible application of a locally isolated environmental isolate, Acinetobacter haemolyticus to remediate Cr(VI) contamination in water system was demonstrated. Cr(VI) reduction by A. haemolyticus seems to favour the lower concentrations (10-30 mg/L). However, incomplete Cr(VI) reduction occurred at 70-100 mg/L Cr(VI). Initial specific reduction rate increased with Cr(VI) concentrations. Cr(VI) reduction was not affected by 1 or 10 mM sodium azide (metabolic inhibitor), 10 mM of PO(4)3-, SO4(2-), SO(3)2-, NO3- or 30 mg/L of Pb(II), Zn(II), Cd(II) ions. However, heat treatment caused significant dropped in Cr(VI) reduction to less than 20% only. A. haemolyticus cells loses its shape and size after exposure to 10 and 50 mg Cr(VI)/L as revealed from TEM examination. The presence of electron-dense particles in the cytoplasmic region of the bacteria suggested deposition of chromium in the cells.
    Matched MeSH terms: Anions/pharmacology; Carbon/pharmacology; Metals, Heavy/pharmacology; Sodium Azide/pharmacology
  3. Flavonoids and linderone from Lindera oxyphylla and their bioactivities
    Hosseinzadeh M, Hadi AH, Mohamad J, Khalilzadeh MA, Cheahd SC, Fadaeinasab M
    Comb Chem High Throughput Screen, 2013 Feb;16(2):160-6.
    PMID: 23173924
    A new linderone A, namely 2-cinnamoyl-3-hydroxy-4, 5-dimethoxycyclopenta-2, 4-dienone (5), together with three known flavonoids (1-3) and one linderone (4), were isolated from the bark of Lindera oxyphylla. Extensive spectroscopic analysis including 1D and 2D-NMR spectra determined their sturctures. In addition, the antioxidant activity of all the compounds has been determined using 2, 2-diphenyl-1-picrylhydrazyl radical scavenging (DPPH), ferric reducing antioxidant power (FRAP) and ferrous ion chelating (FIC) methods. Compound 3 showed excellent DPPH scavenging activity with IC50% value of 8.5 ± 0.004% (μg/mL) which is comparable with vitamin C. This compound, also showed an absorbance value of 1.00 ± 0.06% through FRAP test when compared with Butyl Hydroxy Aniline (BHA). However, FIC showed low activity for all the isolated compounds (chelating activity less than 50%) in comparison with ethylene diamine tetra acetic acid (EDTA). Anticancer activity for all compounds has also been measured on A375 human melanoma, HT-29 colon adenocarcinoma, MCF-7 human breast adenocarcinoma cells, WRL-68 normal hepatic cells, A549 non-small cell lung cancer cells and PC-3 prostate adenocarcinoma cell line. Compound 1 showed A549=65.03%, PC-3=30.12%, MCF-7=47.67, compound 2 showed PC-3=90.13%, compound 3 showed MCF-7=79.57 and for compound 5 MCF-7 is 96.33.
    Matched MeSH terms: Antineoplastic Agents/pharmacology; Antioxidants/pharmacology; Chelating Agents/pharmacology; Flavonoids/pharmacology
  4. Antioxidative constituents of Etlingera elatior
    Mohamad H, Lajis NH, Abas F, Ali AM, Sukari MA, Kikuzaki H, et al.
    J Nat Prod, 2005 Feb;68(2):285-8.
    PMID: 15730265
    Phytochemical studies on the rhizomes of Etlingera elatior have resulted in the isolation of 1,7-bis(4-hydroxyphenyl)-2,4,6-heptatrienone (1), demethoxycurcumin (2), 1,7-bis(4-hydroxyphenyl)-1,4,6-heptatrien-3-one (3), 16-hydroxylabda-8(17),11,13-trien-15,16-olide (4), stigmast-4-en-3-one, stigmast-4-ene-3,6-dione, stigmast-4-en-6beta-ol-3-one, and 5alpha,8alpha-epidioxyergosta-6,22-dien-3beta-ol. Compounds 1 and 4 are new, and their structures were elucidated by analysis of spectroscopic data. Diarylheptanoids 1-3 were found to inhibit lipid peroxidation in a more potent manner than alpha-tocopherol.
    Matched MeSH terms: Antioxidants/pharmacology; Curcumin/pharmacology; Diterpenes/pharmacology; Diarylheptanoids/pharmacology
  5. Fulltext Cytoprotective effect of palm kernel cake phenolics against aflatoxin B1-induced cell damage and its underlying mechanism of action
    Oskoueian E, Abdullah N, Zulkifli I, Ebrahimi M, Karimi E, Goh YM, et al.
    BMC Complement Altern Med, 2015 Oct 30;15:392.
    PMID: 26518905 DOI: 10.1186/s12906-015-0921-z
    BACKGROUND: Palm kernel cake (PKC), a by-product of the palm oil industry is abundantly available in many tropical and subtropical countries. The product is known to contain high levels of phenolic compounds that may impede the deleterious effects of fungal mycotoxins. This study focused on the evaluation of PKC phenolics as a potential cytoprotective agent towards aflatoxin B1 (AFB1)-induced cell damage.

    METHODS: The phenolic compounds of PKC were obtained by solvent extraction and the product rich in phenolic compounds was labeled as phenolic-enriched fraction (PEF). This fraction was evaluated for its phenolic compounds composition. The antioxidant activity of PEF was determined by using 1,1-diphenyl-2-picryl-hydrazil scavenging activity, ferric reducing antioxidant power, inhibition of ß-carotene bleaching, and thiobarbituric acid reactive substances assays. The cytotoxicity assay and molecular biomarkers analyses were performed to evaluate the cytoprotective effects of PEF towards aflatoxin B1 (AFB1)-induced cell damage.

    RESULTS: The results showed that PEF contained gallic acid, pyrogallol, vanillic acid, caffeic acid, syringic acid, epicatechin, catechin and ferulic acid. The PEF exhibited free radical scavenging activity, ferric reducing antioxidant power, ß-carotene bleaching inhibition and thiobarbituric acid reactive substances inhibition. The PEF demonstrated cytoprotective effects in AFB1-treated chicken hepatocytes by reducing the cellular lipid peroxidation and enhancing antioxidant enzymes production. The viability of AFB1-treated hepatocytes was improved by PEF through up-regulation of oxidative stress tolerance genes and down-regulation of pro-inflammatory and apoptosis associated genes.

    CONCLUSIONS: The present findings supported the proposition that the phenolic compounds present in PKC could be a potential cytoprotective agent towards AFB1 cytotoxicity.

    Matched MeSH terms: Phenols/pharmacology*; Plant Extracts/pharmacology*; Free Radical Scavengers/pharmacology; Protective Agents/pharmacology*
  6. Growth, biofilm formation, antifungal susceptibility and oxidative stress resistance of Candida glabrata are affected by different glucose concentrations
    Ng TS, Desa MNM, Sandai D, Chong PP, Than LTL
    Infect Genet Evol, 2016 06;40:331-338.
    PMID: 26358577 DOI: 10.1016/j.meegid.2015.09.004
    Glucose is an important fuel source to support many living organisms. Its importance in the physiological fitness and pathogenicity of Candida glabrata, an emerging human fungal pathogen has not been extensively studied. The present study aimed to investigate the effects of glucose on the growth, biofilm formation, antifungal susceptibility and oxidative stress resistance of C. glabrata. In addition, its effect on the expression of a putative high affinity glucose sensor gene, SNF3 was also investigated. Glucose concentrations were found to exert effects on the physiological responses of C. glabrata. The growth rate of the species correlated positively to the amount of glucose. In addition, low glucose environments were found to induce C. glabrata to form biofilm and resist amphotericin B. Conversely, high glucose environments promoted oxidative stress resistance of C. glabrata. The expression of CgSNF3 was found to be significantly up-regulated in low glucose environments. The expression of SNF3 gene in clinical isolates was found to be higher compared to ATCC laboratory strains in low glucose concentrations, which may explain the better survivability of clinical isolates in the low glucose environment. These observations demonstrated the impact of glucose in directing the physiology and virulence fitness of C. glabrata through the possible modulation by SNF3 as a glucose sensor, which in turn aids the species to adapt, survive and thrive in hostile host environment.
    Matched MeSH terms: Amphotericin B/pharmacology; Antifungal Agents/pharmacology*; Glucose/pharmacology; Hydrogen Peroxide/pharmacology
  7. Effect of recombinant human erythropoietin and doxorubicin in combination on the proliferation of MCF-7 and MDA-MB231 breast cancer cells
    Radwan EM, Abdullah R, Al-Qubaisi MS, El Zowalaty ME, Naadja SE, Alitheen NB, et al.
    Mol Med Rep, 2016 May;13(5):3945-52.
    PMID: 26987078 DOI: 10.3892/mmr.2016.4989
    Patients with cancer often exhibit signs of anemia as the result of the disease. Thus, cancer chemotherapies often include erythropoietin (EPO) in the regime to improve the survival rate of these patients. The aim of the present study was to determine the effect of EPO on doxorubicin-treated breast cancer cells. The cytotoxicity of doxorubicin alone or in combination with EPO against the MCF-7 and MDA-MB‑231 human breast cancer cells were determined using an MTT cell viability assay, neutral red (NR) uptake assay and lactate dehydrogenase (LDH) assay. The estimated half maximal inhibitory concentration values for doxorubicin and the combination of doxorubicin with EPO were between 0.140 and 0.260 µg/ml for all cells treated for 72 h. Treatment with doxorubicin in combination with EPO led to no notable difference in cytotoxicity, compared with treatment with doxorubicin alone. The antiproliferative effect of doxorubicin at a concentration of 1 µg/ml on the MDA‑MB‑231 cells was demonstrated by the decrease in viable cells from 3.6x10(5) at 24 h to 2.1x10(5) at 72 h of treatment. In order to confirm apoptosis in the doxorubicin-treated cells, the activities of caspases-3/7 and ‑9 were determined using a TBE assay. The results indicated that the activities of caspases-3/7 and ‑9 were significantly elevated in the doxorubicin-treated MDA-MB-231 cells by 571 and 645%, respectively, and in the MCF 7 cells by 471 and 345%, respectively, compared with the control cells. EPO did not modify the effect of doxorubicin on these cell lines. The results of the present study suggested that EPO was safe for use in combination with doxorubicin in the treatment of patients with breast cancer and concurrent anemia.
    Matched MeSH terms: Antineoplastic Combined Chemotherapy Protocols/pharmacology*; Doxorubicin/pharmacology; Erythropoietin/pharmacology; Recombinant Proteins/pharmacology
  8. Identification of novel acetylcholinesterase inhibitors: Indolopyrazoline derivatives and molecular docking studies
    Chigurupati S, Selvaraj M, Mani V, Selvarajan KK, Mohammad JI, Kaveti B, et al.
    Bioorg Chem, 2016 08;67:9-17.
    PMID: 27231830 DOI: 10.1016/j.bioorg.2016.05.002
    The synthesis of novel indolopyrazoline derivatives (P1-P4 and Q1-Q4) has been characterized and evaluated as potential anti-Alzheimer agents through in vitro Acetylcholinesterase (AChE) inhibition and radical scavenging activity (antioxidant) studies. Specifically, Q3 shows AChE inhibition (IC50: 0.68±0.13μM) with strong DPPH and ABTS radical scavenging activity (IC50: 13.77±0.25μM and IC50: 12.59±0.21μM), respectively. While P3 exhibited as the second most potent compound with AChE inhibition (IC50: 0.74±0.09μM) and with DPPH and ABTS radical scavenging activity (IC50: 13.52±0.62μM and IC50: 13.13±0.85μM), respectively. Finally, molecular docking studies provided prospective evidence to identify key interactions between the active inhibitors and the AChE that furthermore led us to the identification of plausible binding mode of novel indolopyrazoline derivatives. Additionally, in-silico ADME prediction using QikProp shows that these derivatives fulfilled all the properties of CNS acting drugs. This study confirms the first time reporting of indolopyrazoline derivatives as potential anti-Alzheimer agents.
    Matched MeSH terms: Antioxidants/pharmacology*; Cholinesterase Inhibitors/pharmacology*; Indoles/pharmacology*; Pyrazoles/pharmacology*
  9. Fulltext Competing role of bioactive constituents in Moringa oleifera extract and conventional nutrition feed on the performance of Cobb 500 broilers
    Karthivashan G, Arulselvan P, Alimon AR, Safinar Ismail I, Fakurazi S
    Biomed Res Int, 2015;2015:970398.
    PMID: 25793214 DOI: 10.1155/2015/970398
    The influence of Moringa oleifera (MO) leaf extract as a dietary supplement on the growth performance and antioxidant parameters was evaluated on broiler meat and the compounds responsible for the corresponding antioxidant activity were identified. 0.5%, 1.0%, and 1.5% w/v of MO leaf aqueous extracts (MOLE) were prepared, and nutritional feed supplemented with 0%, 0.5%, 1.0%, and 1.5% w/w of MO leaf meal (MOLM) extracts were also prepared and analysed for their in vitro antioxidant potential. Furthermore, the treated broiler groups (control (T1) and treatment (T2, T3, and T4)) were evaluated for performance, meat quality, and antioxidant status. The results of this study revealed that, among the broilers fed MOLM, the broilers fed 0.5% w/w MOLM (T2) exhibited enhanced meat quality and antioxidant status (P < 0.05). However, the antioxidant activity of the MOLE is greater than that of the MOLM. The LC-MS/MS analysis of MOLM showed high expression of isoflavones and fatty acids from soy and corn source, which antagonistically inhibit the expression of the flavonoids/phenols in the MO leaves thereby masking its antioxidant effects. Thus, altering the soy and corn gradients in conventional nutrition feed with 0.5% w/w MO leaves supplement would provide an efficient and cost-effective feed supplement.
    Matched MeSH terms: Antioxidants/pharmacology*; Fatty Acids/pharmacology; Isoflavones/pharmacology; Plant Extracts/pharmacology*
  10. Trisodium phosphate and sodium hypochlorite are more effective as antimicrobials against Campylobacter and Salmonella on duck as compared to chicken meat
    Sarjit A, Dykes GA
    Int J Food Microbiol, 2015 Jun 16;203:63-9.
    PMID: 25791251 DOI: 10.1016/j.ijfoodmicro.2015.02.026
    Little work has been reported on the use of commercial antimicrobials against foodborne pathogens on duck meat. We investigated the effectiveness of trisodium phosphate (TSP) and sodium hypochlorite (SH) as antimicrobial treatments against Campylobacter and Salmonella on duck meat under simulated commercial water chilling conditions. The results were compared to the same treatments on well-studied chicken meat. A six strain Campylobacter or Salmonella cocktail was inoculated (5 ml) at two dilution levels (10(4) and 10(8) cfu/ml) onto 25 g duck or chicken meat with skin and allowed to attach for 10 min. The meat was exposed to three concentrations of pH adjusted TSP (8, 10 and 12% (w/v), pH 11.5) or SH (40, 50 and 60 ppm, pH 5.5) in 30 ml water under simulated spin chiller conditions (4 °C, agitation) for 10 min. In a parallel experiment the meat was placed in the antimicrobial treatments before inoculation and bacterial cocktails were added to the meat after the antimicrobial solution was removed while all other parameters were maintained. Untreated controls and controls using water were included in all experiments. Bacterial numbers were determined on Campylobacter blood-free selective agar and Mueller Hinton agar or xylose deoxycholate agar and tryptone soya agar using the thin agar layer method for Campylobacter and Salmonella, respectively. All TSP concentrations significantly (p<0.05) reduced numbers of Campylobacter (~1.2-6.4 log cfu/cm(2)) and Salmonella (~0.4-6.6 log cfu/cm(2)) on both duck and chicken meat. On duck meat, numbers of Campylobacter were less than the limit of detection at higher concentrations of TSP and numbers of Salmonella were less than the limit of detection at all concentrations of TSP except one. On chicken meat, numbers of Campylobacter and Salmonella were less than the limit of detection only at the lower inoculum level and higher TSP concentrations. By contrast only some of the concentrations of SH significantly (p<0.05) reduced numbers of Campylobacter and Salmonella (~0.2-1.5 log cfu/cm(2)) on both duck and chicken meats. None of the SH treatments resulted in numbers of either pathogen being less than limit of detection. Results indicate that chicken meat has the ability to effectively protect Campylobacter and Salmonella against the impact of trisodium phosphate and sodium hypochlorite while duck meat does not. This study suggests that trisodium phosphate has a strong potential for application in a commercial poultry processing to reduce Campylobacter and Salmonella specifically on duck meat.
    Matched MeSH terms: Anti-Infective Agents/pharmacology*; Disinfectants/pharmacology; Phosphates/pharmacology*; Sodium Hypochlorite/pharmacology*
  11. Novel effects of deoxycorticosterone on testicular 11beta-hydroxysteroid dehydrogenase activity and plasma testosterone levels in normal and adrenalectomized rats
    Nwe KH, Morat PB, Hamid A, Fadzilah S, Khalid BA
    Exp. Clin. Endocrinol. Diabetes, 1999;107(5):288-94.
    PMID: 10482040
    The 11beta-hydroxysteroid dehydrogenase (11beta-HSD) protects the testis from the inhibitory effects of corticosterone on testosterone (T) production. The objectives of the present studies were to determine the effects of deoxycorticosterone (DOC) and its mechanism of actions on testicular 11beta-HSD activity and plasma T levels after 7 days of treatment. The results revealed that at the end of 7 days treatment, DOC significantly increased testicular 11beta-HSD activity and plasma T levels in normal rats. However, the time course showed that high plasma T levels lowered 11beta-HSD activity on day 14 and by 21 days both the levels normalized. In adrenalectomized (ADX) rats, only the enzyme activity increased significantly but not plasma T levels. Spironolactone, a competitive inhibitor of mineralocorticoid receptor (MR), did not change testicular 11beta-HSD activity in both normal and DOC treated rats suggesting that DOC did not act through MR in increasing 11beta-HSD activity. On the other hand, spironolactone significantly decreased plasma T levels in DOC treated rats. Progesterone (P), a competitive inhibitor of glucocorticoid receptors (GR) or corticosterone significantly suppressed testicular enzyme activity and plasma T levels in DOC treated normal rats. Carbenoxolone which is an inhibitor of 11beta-HSD activity significantly depressed testicular 11beta-HSD activity and plasma T levels in DOC treated normal rats. This paper suggests that DOC increased testicular 11beta-HSD activity through GR; whilst increase in plasma T levels required functioning adrenal glands. The testicular 11beta-HSD is one of the regulators of T levels and vice versa.
    Matched MeSH terms: Carbenoxolone/pharmacology; Desoxycorticosterone/pharmacology*; Progesterone/pharmacology; Spironolactone/pharmacology
  12. Effect of rocuronium compared with succinylcholine on intraocular pressure during rapid sequence induction of anaesthesia
    Chiu CL, Jaais F, Wang CY
    Br J Anaesth, 1999 May;82(5):757-60.
    PMID: 10536557
    We have compared the effect of rocuronium and succinylcholine on intraocular pressure (IOP) during rapid sequence induction of anaesthesia using propofol and fentanyl, in a randomized double-blind study. We studied 30 adult patients, allocated to one of two groups. Anaesthesia was induced with fentanyl 2 micrograms kg-1 and propofol until loss of verbal response. This was followed by succinylcholine 1.5 mg kg-1 (group S; n = 15) or rocuronium 0.9 mg kg-1 (group R; n = 15). Laryngoscopy was performed 60 s later. IOP, mean arterial pressure (MAP) and heart rate (HR) were measured before induction, immediately before intubation and every minute after intubation for 5 min. A Keeler Pulsair air impulse tonometer was used to measure IOP and the mean of two readings obtained in the right eye at each measurement time was recorded. Intubating conditions were evaluated according to a simple scoring system. IOP in the succinylcholine group was significantly greater than that in the rocuronium group (mean 21.6 (SEM 1.4) mm Hg vs 13.3 (1.4) mm Hg; P < 0.001). Intubating conditions were equally good in both groups. We conclude that with rapid sequence induction of anaesthesia using propofol and fentanyl, rocuronium did not cause as great an increase in IOP as succinylcholine and may be an alternative in open eye injury cases.
    Matched MeSH terms: Androstanols/pharmacology*; Neuromuscular Nondepolarizing Agents/pharmacology*; Neuromuscular Depolarizing Agents/pharmacology*; Succinylcholine/pharmacology*
  13. Novel halogenated metabolites from the Malaysian Laurencia pannosa
    Suzuki M, Daitoh M, Vairappan CS, Abe T, Masuda M
    J Nat Prod, 2001 May;64(5):597-602.
    PMID: 11374951
    In connection with our chemotaxonomic studies of Malaysian species of the red algal genus Laurencia, the chemical composition of Laurencia pannosa Zanardini was examined. Two halogenated sesquiterpenoids, named pannosanol (1) and pannosane (2), have been isolated along with a halogenated C15-acetogenin, (3Z)-chlorofucin (3). The structures of these compounds were determined from their spectroscopic data (IR, 1H NMR, 13C NMR, 2D NMR, and MS). Pannosanol and pannosane are novel halometabolites with an unusual rearranged chamigrane framework. Antibacterial activities of these metabolites against marine bacteria are also described.
    Matched MeSH terms: Anti-Bacterial Agents/pharmacology; Furans/pharmacology*; Lactones/pharmacology*; Sesquiterpenes/pharmacology*
  14. Effect of retinoic acid and palm oil carotenoids on oestrone sulphatase and oestradiol-17beta hydroxysteroid dehydrogenase activities in MCF-7 and MDA-MB-231 breast cancer cell lines
    Ng JH, Nesaretnam K, Reimann K, Lai LC
    Int J Cancer, 2000 Oct 1;88(1):135-8.
    PMID: 10962451
    Oestrogen is important in the development of breast cancer. Oestrogen receptor positive breast cancers are associated with a better prognosis than oestrogen-receptor negative breast cancers since they are more responsive to hormonal treatment. Oestrone sulphate acts as a huge reservoir for oestrogens in the breast. It is converted to the potent oestrogen, oestradiol (E(2)) by the enzymes oestrone sulphatase and oestradiol-17beta hydroxysteroid dehydrogenase (E(2)DH). Retinoic acid and carotenoids have been shown to have chemopreventive activity against some cancers. The aim of our study was to determine and compare the effects of retinoic acid and palm oil carotenoids on growth of and oestrone sulphatase and E(2)DH activities in the oestrogen receptor positive, MCF-7 and oestrogen receptor negative, MDA-MB-231 breast cancer cell lines. Retinoic acid and carotenoids inhibited MCF-7 cell growth but had no effect on MDA-MB-231 cell growth. Both retinoic acid and carotenoids stimulated oestrone sulphatase activity in the MCF-7 cell line. E(1) to E(2) conversion was inhibited by 10(-7) M carotenoids but was stimulated at 10(-6) M in the MCF-7 cell line. Retinoic acid had no effect on E(1) to E(2) conversion at 10(-7) M but stimulated E(1) to E(2) conversion at 10(-6) M. Retinoic acid and carotenoids had no effect on E(2) to E(1) conversion in the MCF-7 cell line. Retinoic acid stimulated E(1) to E(2) conversion in the MDA-MB-231 cell line but had no effect on oestrone sulphatase activity or E(2) to E(1) conversion in this cell line. Both oestrone sulphatase and E(2)DH activity were not affected by carotenoids in the MDA-MB-231 cell line. In conclusion, retinoic acid and carotenoids may prevent the development of hormone-dependent breast cancers since they inhibit the growth of the MCF-7 cell line.
    Matched MeSH terms: Antineoplastic Agents/pharmacology*; Carotenoids/pharmacology*; Plant Oils/pharmacology*; Tretinoin/pharmacology
  15. Opposite effects of sex steroids on 11 beta-hydroxysteroid dehydrogenase activity in the normal and adrenalectomized rat testis
    Nwe KH, Morat PB, Khalid BA
    Gen. Pharmacol., 1997 May;28(5):661-4.
    PMID: 9184798
    1. Sex steroids have been shown to regulate the biosynthesis of 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD). 2. In vitro studies showed that oestradiol (E2) or testosterone (T) can interfere with the bioassay of enzyme activity, but not progesterone (P4). 3. For in vivo studies, the activity of 11 beta-HSD in the testis of normal and adrenalectomized (ADX) adult male Wistar rats was determined following a daily IM injection of sex steroids for 7 days. 4. The 11 beta-HSD activity was significantly reduced (P < 0.01) either by E2 or T in normal and ADX rats. The enzyme activity in normal rats given both T and E2 was even lower (P < 0.001) than when E2 was given alone. 5. P4 given to normal and ADX rats increased the enzyme activity higher than normal (P < 0.001). 6. The presence of corticosteroids influenced the effects of E2, but not of T and P4, on 11 beta-HSD activity. 7. E2 and T downregulate 11 beta-HSD activity, whereas P4 increased it. E2 did not act through lowering T level.
    Matched MeSH terms: Estradiol/pharmacology; Progesterone/pharmacology; Gonadal Steroid Hormones/pharmacology*; Testosterone/pharmacology
  16. Fulltext Analysis of expression of vitamin E-binding proteins in H2O2 induced SK-N-SH neuronal cells supplemented with α-tocopherol and tocotrienol-rich fraction
    Chiroma AA, Khaza'ai H, Abd Hamid R, Chang SK, Zakaria ZA, Zainal Z
    PLoS One, 2020;15(11):e0241112.
    PMID: 33232330 DOI: 10.1371/journal.pone.0241112
    Natural α-tocopherol (α-TCP), but not tocotrienol, is preferentially retained in the human body. α-Tocopherol transfer protein (α-TTP) is responsible for binding α-TCP for cellular uptake and has high affinity and specificity for α-TCP but not α-tocotrienol. The purpose of this study was to examine the modification of α-TTP together with other related vitamin E-binding genes (i.e., TTPA, SEC14L2, and PI-TPNA) in regulating vitamin E uptake in neuronal cells at rest and under oxidative stress. Oxidative stress was induced with H2O2 for an hour which was followed by supplementation with different ratios of α-TCP and tocotrienol-rich fraction (TRF) for four hours. The cellular levels of vitamin E were quantified to determine bioavailability at cellular levels. The expression levels of TTPA, SEC14L2, and PI-TPNA genes in 0% α-TCP were found to be positively correlated with the levels of vitamin E in resting neuronal cells. In addition, the regulation of all the above-mentioned genes affect the distribution of vitamin E in the neuronal cells. It was observed that, increased levels of α-TCP secretion occur under oxidative stress. Thus, our results showed that in conclusion vitamin E-binding proteins may be modified in the absence of α-TCP to produce tocotrienols (TCT), as a source of vitamin E. The current study suggests that the expression levels of vitamin E transport proteins may influence the cellular concentrations of vitamin E levels in the neuronal cells.
    Matched MeSH terms: Hydrogen Peroxide/pharmacology*; Neuroprotective Agents/pharmacology; alpha-Tocopherol/pharmacology*; Tocotrienols/pharmacology*
  17. Fulltext Synergetic Influence of Bismuth Oxide Nanoparticles, Cisplatin and Baicalein-Rich Fraction on Reactive Oxygen Species Generation and Radiosensitization Effects for Clinical Radiotherapy Beams
    Talik Sisin NN, Abdul Razak K, Zainal Abidin S, Che Mat NF, Abdullah R, Ab Rashid R, et al.
    Int J Nanomedicine, 2020;15:7805-7823.
    PMID: 33116502 DOI: 10.2147/IJN.S269214
    Purpose: This study aimed to quantify synergetic effects induced by bismuth oxide nanoparticles (BiONPs), cisplatin (Cis) and baicalein-rich fraction (BRF) natural-based agent on the reactive oxygen species (ROS) generation and radiosensitization effects under irradiation of clinical radiotherapy beams of photon, electron and HDR-brachytherapy. The combined therapeutic responses of each compound and clinical radiotherapy beam were evaluated on breast cancer and normal fibroblast cell line.

    Methods: In this study, individual BiONPs, Cis, and BRF, as well as combinations of BiONPs-Cis (BC), BiONPs-BRF (BB) and BiONPs-Cis-BRF (BCB) were treated to the cells before irradiation using HDR brachytherapy with 0.38 MeV iridium-192 source, 6 MV photon beam and 6 MeV electron beam. The individual or synergetic effects from the application of the treatment components during the radiotherapy were elucidated by quantifying the ROS generation and radiosensitization effects on MCF-7 and MDA-MB-231 breast cancer cell lines as well as NIH/3T3 normal cell line.

    Results: The ROS generated in the presence of Cis stimulated the most substantial amount of ROS compared to the BiONPs and BRF. Meanwhile, the combination of the components had induced the higher ROS levels for photon beam than the brachytherapy and electron beam. The highest ROS enhancement relative to the control is attributable to the presence of BC combination in MDA-MB-231 cells, in comparison to the BB and BCB combinations. The radiosensitization effects which were quantified using the sensitization enhancement ratio (SER) indicate the highest value by BC in MCF-7 cells, followed by BCB and BB treatment. The radiosensitization effects are found to be more prominent for brachytherapy in comparison to photon and electron beam.

    Conclusion: The BiONPs, Cis and BRF are the potential radiosensitizers that could improve the efficiency of radiotherapy to eradicate the cancer cells. The combination of these potent radiosensitizers might produce multiple effects when applied in radiotherapy. The BC combination is found to have the highest SER, followed by the BCB combination. This study is also the first to investigate the effect of BRF in combination with BiONPs (BB) and BC (BCB) treatments.

    Matched MeSH terms: Bismuth/pharmacology*; Cisplatin/pharmacology*; Radiation-Sensitizing Agents/pharmacology; Flavanones/pharmacology*
  18. Fulltext Investigation of the Adrenergic and Opioid Binding Affinities, Metabolic Stability, Plasma Protein Binding Properties, and Functional Effects of Selected Indole-Based Kratom Alkaloids
    Obeng S, Kamble SH, Reeves ME, Restrepo LF, Patel A, Behnke M, et al.
    J Med Chem, 2020 01 09;63(1):433-439.
    PMID: 31834797 DOI: 10.1021/acs.jmedchem.9b01465
    Selected indole-based kratom alkaloids were evaluated for their opioid and adrenergic receptor binding and functional effects, in vivo antinociceptive effects, plasma protein binding, and metabolic stability. Mitragynine, the major alkaloid in Mitragyna speciosa (kratom), had higher affinity at opioid receptors than at adrenergic receptors while the vice versa was observed for corynantheidine. The observed polypharmacology of kratom alkaloids may support its utilization to treat opioid use disorder and withdrawal.
    Matched MeSH terms: Analgesics/pharmacology*; Dopamine Agents/pharmacology*; Adrenergic Agents/pharmacology*; Secologanin Tryptamine Alkaloids/pharmacology*
  19. New triazinoindole bearing thiazole/oxazole analogues: Synthesis, α-amylase inhibitory potential and molecular docking study
    Rahim F, Tariq S, Taha M, Ullah H, Zaman K, Uddin I, et al.
    Bioorg Chem, 2019 11;92:103284.
    PMID: 31546207 DOI: 10.1016/j.bioorg.2019.103284
    New triazinoindole bearing thiazole/oxazole analogues (1-21) were synthesized and characterized through spectroscopic techniques such as HREI-MS, 1H and 13C NMR. The configuration of compound 2i and 2k was confirmed through NOESY. All analogues were evaluated against α-amylase inhibitory potential. Among the synthesized analogues, compound 1h, 1i, 1j, 2a and 2f having IC50 values 1.80 ± 0.20, 1.90 ± 0.30, 1.2 ± 0.30, 1.2 ± 0.01 and 1.30 ± 0.20 μM respectively, showed excellent α-amylase inhibitory potential when compared with acarbose as standard (IC50 = 0.91 ± 0.20 µM). All other analogues showed good to moderate inhibitory potential. Structural activity relationship (SAR) has been established and binding interactions were confirmed through docking studies.
    Matched MeSH terms: Oxazoles/pharmacology*; Thiazoles/pharmacology*; Triazines/pharmacology*; Glycoside Hydrolase Inhibitors/pharmacology*
  20. Estrogenic phytochemical from Labisia pumila (Myrsinaceae) with selectivity towards estrogen receptor alpha and beta subtypes
    Muhamad M, Choo CY, Hasuda T, Hitotsuyanagi Y
    Fitoterapia, 2019 Sep;137:104256.
    PMID: 31295513 DOI: 10.1016/j.fitote.2019.104256
    Labisia pumila var. alata (Myrsinaceae) or "Kacip fatimah" is a famous Malay traditional herb used for the maintenance of women's health. The extracts of L.pumila displayed estrogenic activity in rats. Nonetheless, the estrogenic bioactives were not identified. The aim of the study is to identify estrogenic compounds contributing to the established estrogenic activity. Bioactivity-guided-isolation method guided the isolation of pure bioactives. The hexane extract was subjected to a series of silica gel flash and open column chromatography with increasing amount of ethyl acetate in hexane or methanol in chloroform. Each fraction or pure compounds were evaluated on it's estrogen receptor (ER) binding activity with the fluorescence polarization competitive ERα and ERβ binding assay kit. Cytotoxic assay using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay method was used to establish the cytotoxic activity of the compounds. Four alkyl resorcinols and a dimeric 1,4-benzoquinone, namely belamcandol B (1), 5-pentadec-10'-(Z)-enyl resorcinol (2), 1,3-dihydroxy-5-pentadecylbenzene (3), 5-(heptadec-12'-(Z)-enyl) resorcinol (4) and demethylbelamcandaquinone B (5) were identified with selective binding affinities towards either ERα or ERβ exhibiting selectivity ratio from 0.15-11.9. Alkyl resorcinols (2)-(4) exhibited cytotoxic activity towards HL60 cells with IC50 values from 19.5-22.0 μM. Structural differences between compounds influence the binding affinities to ER subtypes. Further study is needed to establish the agonist or antagonist effect of these compounds on various tissues and to identify if these compounds exert cytotoxic activity through the ERs. When consuming L.pumila as a complementary medicine, careful consideration regarding it's estrogenic compound content should be given due consideration.
    Matched MeSH terms: Estrogens/pharmacology*; Resorcinols/pharmacology; Benzoquinones/pharmacology; Phytochemicals/pharmacology
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