MOSP - Macao Scientific Publishers

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Recent progress in the chemo-enzymatic peptide synthesis

Feifei Chen, Fangkai Zhang, Anming Wang*, Haifeng Li, Qiuyan Wang, Zhaowu Zeng, Shuling Wang and Tian Xie

Abstract: Peptides are molecules of paramount importance in several fields, especially in health care and nutrition. They have many beneficial health effects, such as antimicrobial, antiviral, antitumor, neuroactive and immunoactive activity. Several technologies for their production are now available such as chemical synthesis, biosynthesis and chemo-enzymatic peptide synthesis. For combining the advantages of chemical and enzymatic synthesis methods, chemo-enzymatic peptide synthesis has been attracting the interest of researchers in the peptide synthesis. In this paper, new progress in this method was reported. Enzymes, solvent systems and possible mechanisms were presented. The main strategies of chemo-enzymatic synthesis of peptides and modification of enzymes by using different methods were also discussed.[...] Read More.

Keywords: Peptides, enzymes, solvent systems, chemo-enzymatic synthesis, genetic engineering, one-pot synthesis.

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Polyphenolic fractions of Algerian propolis reverses doxorubicin induced acute renal oxidative stress

Mesbah Lahouel,*, Kheira Boutabet, Wided Kebsa and Mohamed Alyane

Abstract: The most important pharmacologically active constituents in propolis are flavanoids with a broad spectrum of biological activities varying with their chemical composition. Propolis chemical composition depends on the floral and geographical origin present at the site of collection and thus in the climatic characteristics. However, until now, no mitochondrial functions in relation to stress and apoptotic process were determined. We hypothesized that propolis effects could be due to a direct action on mitochondrial functions. We evaluated whether polyphenols compounds had preventive properties against renal oxidative stress induced by doxorubicin. We present here an analytical and pharmacological study of the eastern Algerian propolis using Thin layer Chrommatography (TLC), Ultra Violet-High Phase Liquid Chromatography (UV-HPLC) and Gas Chromatography-Mass Spectrometry (GC-MS). The pharmacological study was carried out in vivo on wistar rat pre-treated with propolis extract 100 mg/kg/day for 7 days. Doxorubicin at 10 mg/kg of body weight was administered intravenously on day 7th. Serum creatinine concentration, scavenging effect of flavonoids, lipid peroxydation (MDA) and glutathione (GSH) concentration were measured. Chemical analysis allowed identification and quantification of the phenolic compounds including pinostrombin chalcone(38.91%), galangin(18.95), naringenin(14.27%), tectochrysin(25.09%), methoxychrysin(1.14%) and a prenylated coumarin compound suberosin (1.65%). The total flavonoid concentration in the propolis extract determined by aluminum chloride colorimetric method was 370 mg (quercetin equivalents QE) /g dry weight of propolis extract (QE/g DWPE). Data suggest protective effects of an Algerian propolis extract against doxorubicin-induced oxidative stresses. It restored the renal functions and clearly reduced the toxic effect of the drug.[...] Read More.

Keywords: Algerian propolis, chemical analysis, flavonoids, renal oxidative stress.

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Cytotoxic activity of leaf and rhizome extracts of Alpinia scabra (Blume) NÃ¡ves, a wild ginger from Peninsular Malaysia

Full Length Research Paper

Abstract: The leaves and rhizomes of Alpinia scabra (Zingiberaceae) were investigated for their cytotoxic effect against selected human cancer cell lines, namely MCF7 (hormone-dependant breast carcinoma cell line), HT29 (colon carcinoma cell line) and SKOV-3 (ovarian cancer cell line) by using an in vitro neutral red cytotoxicity assay. The methanol extracts of both leaves and rhizomes did not show active cytotoxic activity against the selected cancer cell lines. The n-hexane extract of the leaves exhibited remarkable cytotoxic effect against SKOV-3 cells with IC50 value of 6.3 µg/ml while dichloromethane extract showed high cytotoxic effect against MCF7 and SKOV-3 with IC50 values of 6.7 and 5.9 µg/ml, respectively. The n-hexane and dichloromethane extracts of the rhizomes possessed high cytotoxic effect against SKOV- 3 cells with IC50 values of 8.3 and 7.0 µg/ml, respectively. This is the first report of the cytotoxic activity of A. scabra.[...] Read More.

Keywords: Zingiberaceae, Alpinia scabra, cytotoxic activity, cancer cell lines.

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Microencapsulation and pharmacological evaluations for the anti-fertility effect of castor bean extract in female mice

Yi-ling Hou*, Xiang Ding, Shuang-quan Duan, Zhi-rong Yang and Ping Gao

Abstract: Castor Bean (Ricinus communis, Family Euphorbiaceae) ethanol extraction (CBE) possesses potent antifertility effect, but the absorption of it is limited. Therefore, this study was aimed to prepare CBE microparticles for targeted drug effect. Poly (toluene-2, 4-di-isocyanate and ethylene alcohol) (TDI-EA) microparticles loaded with CBE were prepared by Interracial polymerization, a semi-industrial technique capable of encapsulating fragile molecules maintaining their native properties. The effects of several parameters on the properties of the particles were investigated. Microparticles showed of CBE- TDI-EA microparticles following 200, 400 and 600 mg/kg with a content of 5 mg two mean diameters that were 4 and 120 m, separately, which are suitable for their absorption. Entrapment efficiency of CBEM in TDI-EA microparticles was 98.3%. The drug efficiency ranged from 73.26 to 100% depending on the drug consumption. The optimal growth suppression of the Kunming strain female mice vital organs could be achieved by oral application CBE in 6 mg microparticles while the Control Group showed the normal growth of the vital organs and CBE at the same concentration in solution form could not suppress the growth of the vital organs to the same extent. Finally, a bioassay demonstrated that the in vivo CBE microparticles have a strong depression of fertility without significant adverse reaction.[...] Read More.

Keywords: Antifertility, castor bean extract, female mice, microencapsulation.

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Effects of intestinal trefoil factor on PI3K and caspase-3/9 in newborn rats with necrotizing enterocolitis

Cai-Xia Yan, He-Sheng Luo, Bing-Hong Zhang*, Ri-Hong Zhao and Hai-Xia Zhang

Abstract: PI3K/Akt signal pathway was blocked by Wortmannin, a specific inhibitor of phosphoinositide-3 kinase (PI3K), and the effects of intestinal trefoil factor (ITF) on PI3K and caspase-3/9 in newborn rats with necrotizing enterocolitis (NEC) were investigated to explore the protective mechanism of ITF against NEC. Experimental NEC was induced by exposure to hypoxia for 60 sec followed by cold stress at 4°C for 10 min. A total of 50 One-day-old Wistar rats were randomly divided into five groups : group A, NEC+NS; group B, NEC+ITF; group C,NEC+ wortmannin; group D ,NEC+ wortmannin + ITF; group E , Normal control. The animals were euthanized at development of NEC, and at 96 h the intestinal tissue was harvested and examined for histological changes of NEC, and then the PI3K content and Caspase-3/9 activity were detected using ELISA and spectrophotometry, respectively. The PI3K content (pg/ml) in group A was slightly higher than group E (P0.05), but the PI3K content (pg/ml) in group B was significantly higher than the remaining groups (P[...] Read More.

Keywords: Intestinal trefoil factor, necrotizing enterocolitis, PI3K/Akt signal transduction, Caspase-9, Caspase-3.

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In vitro and in vivo evaluation of two sustained release formulations of diltiazem HCl

Muhammad Rafiq, Abdul Wahab*, Nisar-ur-Rehman, Abid Hussain and Said Muhammad

Abstract: In the present study, two sustained release solid and semi-solid matrices were developed using Hydroxypropyl methyl cellulose (HPMC) and Gelucire derivative, Gelucire 50/30. The purpose of the study was in vitro and in vivo correlation of these two sustained release formulations with SR capsules available in market and to know that for how long the preparation containing HPMC and Gelucire work in the body as compared to the product circulating in the market, so for this two formulations were developed such as solid matrices in tablets form and semi-solid capsules. For the preparation of solid matrices, direct compression method and for semi-solid, filling capsule technology were used. In vitro and in vivo study was perfomed and different parameters were studied such as Cmax, Tmax and AUC for all the three formulations. For determination of Cmax, Tmax ans AUC statistical models were used. In vitro study showed that more than 80% drug was released upto 12 h from all the three formulations and no significance difference was observed in release pattern while in vivo study showed prolonged release of the two test formulations after applying statistical models. The drug release from both test formulations was slow thereby providing a prolonged and controlled in vivo delivery of the drug. This proved the superiority of our test capsules and tablets over the reference capsules.[...] Read More.

Keywords: In vitro and in vivo correlation, deltiazem, kinetic models, statistical analysis.

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Prohibitive effect of lactoperoxidase system (LPS) on some pathogen fungi and bacteria

Melda Sisecioglu, Ekrem Kirecci, Murat Cankaya, Hasan Ozdemir, Ilhami Gulcin,* and Ali Atasever

Abstract: Lactoperoxidase is a peroxidase enzyme found in milk. This enzyme has antimicrobial and antioxidant properties. It is fairly heat resistant and was widely used as an indicator of over pasteurization of milk. In the present study, bovine lactoperoxidase (LPO) was purified from skimmed milk using amberlite-CG-50-H+ resin, CM-sephadex-C-50 ion-exchange chromatography and sephadex-G-100 gel filtration chromatography. Enzyme activity was determined using 2, 2-azino-bis-diammonium salt as a chromogenic substrate at pH 6, and purification degree was controlled by means of sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Antibacterial and antifungal activity of bovine lactoperoxidase was determined by disk diffusion method. Bovine LPO exhibited high antifungal and antibacterial activity in 100 mM thiocynate-100 mM hydrogen peroxide (H2O2) medium on some fungi (Candida albicans, Candida glabrata, Candida krusei, Candida parapsilosis and Saccharomyces boulardii) and bacteria (Citrobacter freundii, Escherichia coli, Streptococcus pneumoniae, Staphylococcus epidermidis and Staphylococcus intermedius), respectively. Antibacterial and antifungal activity of LPO system was compared to those of well known antibacterial and antifungal substances such as cefaclor, erythromycin, tetracycline and fluconazole. This study has investigated for the first time the antifungal and antibacterial effects of bovine LPO system on C. albicans, C. glabrata, C. krusei, C. parapsilosis, S. boulardii, S. pneumoniae, S. epidermidis and S. intermedius.[...] Read More.

Keywords: Milk, enzyme, lactoperoxidase, LPO, antibacterial, antifungal.

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Effect of methionine on hepatic indices in male Wistar rat dosed to acetaminophen formulation

A. A. Iyanda*, J. I. Anetor, F. A. A. Adeniyi and C. I. Iheakanwa

Abstract: Studies’ reports in both humans and experimental animals have supported the use of methionine as an effective antidote to counteract the manifestation of hepatotoxicity, which is a common occurrence of acetaminophen at overdose levels of exposure. This study was embarked on to test the hepatoprotective effect of methionine in acetaminophen tablets, produced by a leading paracetamol brand in Nigeria especially in ameliorating the hepatocellular damage for which acetaminophen is noted for. Ten percent methionine was detected in this formulation using HPLC technique. Twenty male Wistar rats were used for this purpose, they were divided equally into four groups, and the first group served as the control and received 2 ml of physiologic saline per rat. The other three groups served as the test groups and received 100, 350 and 1000 mgkg BW of acetaminophen dissolved in 2 ml of physiologic saline per rat. The drug was introduced into the rats by intra-peritoneal route of administration. The study lasted for 48 h after which the animals were sacrificed and blood obtained by cardiac puncture. Results showed that all these hepatotoxic indices and liver function tests (aspartate and alanine amino transferases, alkaline phoshatase, total and conjugated bilirubin, total proteins, albumin and globulins) of rats in both 350 and 1000 mgkg levels were not statistically different compared to the controls (p > 0.05). The rats in the 100 mgkg set showed the same pattern except that total proteins and globulins were statistically increased in these rats compared to controls (p < 0.05). These results therefore, show that methionine containing acetaminophen in tablet form ameliorated the toxic effects of acetaminophen even at toxic level of 1000 mgkg level BW.[...] Read More.

Keywords: Hepatocellular damage, male Wistar rats, acetaminophen formulation.

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Effects of short -term exercise on heart-rate blood pressure oxidative stress paraoxonase activity and lipid hydroperoxide

Selçuk Özda

Abstract: This study inquired the effects of short-term exercise on heart-beats, blood pressure, total anti-oxidative capacity (TAC), total oxidative stress (TOS), lipid hydro-peroxide (LOOHs) and Paraoxonase (PON) in football players. 22 male football players, who perform exercise regularly at least three times a week and two hours a day, participated in this study on voluntary basis. Heart-beats, systolic and diastolic blood pressures and blood samples were taken from the football players before and right after the short-term exercise. Their Total Antioxidant Capacity (TAC), Total Oxidative Stress (TOS), Lipid Hydro-peroxide (LOOHs) and Paraoxonase (PON) levels were measured and assessed. It was found that football players displayed significant increase in heart -beats (p < 0.01) and systolic blood pressure (p < 0.05), significant decrease in TAC values (p < 0.05), and significant increase in the oxidative status (TOS) value (p < 0.05) after the short-term exercise compared to the pre-exercise levels. No significant change was observed in diastolic blood pressure, lipid hydro-peroxide (LOOHs) and Paraoxonase (PON) levels. In this study, it was found that the balance shifted towards oxidative stress due to decreased antioxidants and increased oxidants after short -term exercise. In order to reduce such a high oxidative stress and to prevent athletes from its adverse effects, it necessary to have an antioxidant-rich diet before any exercise or to get antioxidant supplements.[...] Read More.

Keywords: Football, short-term exercise, oxidants, antioxidants.

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Phytochemical screening and antimicrobial activities of Euphorbia balsamifera leaves, stems and root against some pathogenic microorganisms

A.S. Kamba* and L. G. Hassan

Abstract: Plants and plant-based products are the bases of many of the modern pharmaceuticals we use today for various ailments. The objective of the study is to determine the bioactive chemical constituents and to evaluate extracts of Euphorbia balsamifera leaves, stem and root for in vitro antimicrobial activities by seagar dilution method. Phytochemical analysis of the crude extracts of the plant parts revealed the presence of tannins, saponins, steroid, terpenoid, flavonoids, cardic glycosides and balsam (gum). The extract of E. balsamifera leaves, stem and roots were mostly effective against the Salmonella typhimurium, Pseudomonas aeroginosa, Klebsiella spp., Escherichia coli and Candida albicans. Thin layer chromatography (TLC) revealed four, three and two spots for ethanol, petroleum ether and chloroform extracts respectively using ethyl acetate: hexane solvent mixture. The minimum inhibitory concentrations (MIC) of the crude extracts were determined for the various organisms which ranged between 5.0 and 6.0 mg/ml while the minimum bactericidal concentration (MBC) ranged between 4.5 and 6.0 mg/ml. E. balsamifera could be a potential source of antimicrobial agents.[...] Read More.

Keywords: Euphorbia balsamifera, phytochemical screening, plant extracts and zone of inhibitions.

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