Displaying publications 641 - 660 of 1845 in total

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  1. Colour, phenolic content and antioxidant capacity of some fruits dehydrated by a combination of different methods
    Chong CH, Law CL, Figiel A, Wojdyło A, Oziembłowski M
    Food Chem, 2013 Dec 15;141(4):3889-96.
    PMID: 23993562 DOI: 10.1016/j.foodchem.2013.06.042
    The objective of this study was to improve product quality of dehydrated fruits (apple, pear, papaya, mango) using combined drying techniques. This involved investigation of bioactivity, colour, and sensory assessment on colour of the dried products as well as the retention of the bio-active ingredients. The attributes of quality were compared in regard to the quality of dehydrated samples obtained from continuous heat pump (HP) drying technique. It was found that for apple, pear and mango the total colour change (ΔE) of samples dried using continuous heat pump (HP) or heat pump vacuum-microwave (HP/VM) methods was lower than of samples dried by other combined methods. However, for papaya, the lowest colour change exhibited by samples dried using hot air-cold air (HHC) method and the highest colour change was found for heat pump (HP) dehydrated samples. Sensory evaluation revealed that dehydrated pear with higher total colour change (ΔE) is more desirable because of its golden yellow appearance. In most cases the highest phenol content was found from fruits dried by HP/VM method. Judging from the quality findings on two important areas namely colour and bioactivity, it was found that combined drying method consisted of HP pre-drying followed by VM finish drying gave the best results for most dehydrated fruits studied in this work as the fruits contain first group of polyphenol compounds, which preferably requires low temperature followed by rapid drying strategy.
    Matched MeSH terms: Antioxidants/chemistry*
  2. A novel high throughput method based on the DPPH dry reagent array for determination of antioxidant activity
    Musa KH, Abdullah A, Kuswandi B, Hidayat MA
    Food Chem, 2013 Dec 15;141(4):4102-6.
    PMID: 23993591 DOI: 10.1016/j.foodchem.2013.06.112
    A stable chromogenic radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) is commonly used for the determination of antioxidant activity. In this paper, DPPH was dried into 96 well microplate to produce DPPH dry reagent array plate, based on which the highly sensitive and high throughput determination of antioxidant activities was achieved. The spectrophotometric characterization of the microplate containing dried or fresh DPPH free radicals was reported. The response of the DPPH dry reagent array towards different standard antioxidants was studied. The reaction for DPPH in fresh or dry reagent array with Trolox was reported and compared. The DPPH dry reagent array was used to study the antioxidant activity of banana, green tea, pink guava, and honeydew and the results were compared to the samples reacted with freshly prepared DPPH. The proposed method is comparable to the classical DPPH method, more convenient, simple to operate with minimal solvent required and excellent sensitivity.
    Matched MeSH terms: Antioxidants/chemistry*
  3. Fulltext Optimal binary solvent extraction system for phenolic antioxidants from mengkudu (Morinda citrifolia) fruit
    Thoo YY, Ho SK, Abas F, Lai OM, Ho CW, Tan CP
    Molecules, 2013 Jun 14;18(6):7004-22.
    PMID: 23771061 DOI: 10.3390/molecules18067004
    Antioxidants have been widely used in the food industry to enhance product quality by preventing oxidation of susceptible substances. This work was carried out to maximise the recovery of total phenolic content (TPC), total flavonoid content (TFC), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical-scavenging capacity and 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging capacity from Morinda citrifolia fruit via modification of the ethanol concentration, extraction time and extraction temperature at minimal processing cost. The optimised conditions yielded values of 881.57 ± 17.74 mg GAE/100 g DW for TPC, 552.53 ± 34.16 mg CE/100 g DW for TFC, 799.20 ± 2.97 µmol TEAC/100 g DW for ABTS and 2,317.01 ± 18.13 µmol TEAC/100 g DW for DPPH were 75% ethanol, 40 min of time and 57 °C. The four responses did not differ significantly (p > 0.05) from predicted values, indicating that models obtained are suitable to the optimisation of extraction conditions for phenolics from M. citrifolia. The relative amounts of flavonoids were 0.784 ± 0.01 mg quercetin/g of extract and 1.021 ± 0.04 mg rutin/g of extract. On the basis of the results obtained, M. citrifolia extract can be used as a valuable bioactive source of natural antioxidants.
    Matched MeSH terms: Antioxidants/chemistry*
  4. Fulltext Antidiabetic and antioxidant properties of Ficus deltoidea fruit extracts and fractions
    Misbah H, Aziz AA, Aminudin N
    BMC Complement Altern Med, 2013;13:118.
    PMID: 23718315 DOI: 10.1186/1472-6882-13-118
    Diabetes is a serious metabolic disorder affecting the metabolism of carbohydrate, protein and fat. A number of studies have shown that diabetes mellitus is associated with oxidative stress, leading to an increased production of reactive oxygen species. Ficus deltoidea is traditionally used in Malaysia for regulating blood sugar, blood pressure and cholesterol levels. The use of F. deltoidea as an alternative medicinal herb is increasingly gaining popularity with the sale of F. deltoidea tea bags and capsules in the local market. The present study was undertaken to investigate the antidiabetic and antioxidant activities of the fruits from different varieties of F. deltoidea, employing in vitro methods.
    Matched MeSH terms: Antioxidants/chemistry*
  5. Fulltext Evaluation of antioxidant properties and mineral composition of Purslane (Portulaca oleracea L.) at different growth stages
    Uddin MK, Juraimi AS, Ali ME, Ismail MR
    Int J Mol Sci, 2012;13(8):10257-67.
    PMID: 22949859 DOI: 10.3390/ijms130810257
    The main objective of this research was to appraise the changes in mineral content and antioxidant attributes of Portulaca oleracea over different growth stages. The antioxidant activity was measured using 1,1-diphenyl-2-picrylhydrazyl (DPPH), ferric-reducing antioxidant power (FRAP) assays. The iodine titration method was used to determine the ascorbic acid content (AAC). DPPH scavenging (IC(50)) capacity ranged from 1.30 ± 0.04 to 1.71 ± 0.04 mg/mL, while the ascorbic acid equivalent antioxidant activity (AEAC) values were 229.5 ± 7.9 to 319.3 ± 8.7 mg AA/100 g, total phenol content (TPC) varied from 174.5 ± 8.5 to 348.5 ± 7.9 mg GAE/100 g. AAC 60.5 ± 2.1 to 86.5 ± 3.9 mg/100 g and FRAP 1.8 ± 0.1 to 4.3 ± 0.1 mg GAE/g. There was good correlation between the results of TPC and AEAC, and between IC(50) and FRAP assays (r(2) > 0.9). The concentrations of Ca, Mg, K, Fe and Zn increased with plant maturity. Calcium (Ca) was negatively correlated with sodium (Na) and chloride (Cl), but positively correlated with magnesium (Mg), potassium (K), iron (Fe) and zinc (Zn). Portulaca olerecea cultivars could be used as a source of minerals and antioxidants, especially for functional food and nutraceutical applications.
    Matched MeSH terms: Antioxidants/analysis*
  6. Inhibitory activities of compounds from the twigs of Garcinia hombroniana Pierre on human low-density lipoprotein (LDL) oxidation and platelet aggregation
    Saputri FC, Jantan I
    Phytother Res, 2012 Dec;26(12):1845-50.
    PMID: 22422639 DOI: 10.1002/ptr.4667
    The methanol extract of the twigs of Garcinia hombroniana, which showed strong LDL antioxidation and antiplatelet aggregation activities, was subjected to column chromatography to obtain 3,5,3',5'-tetrahydroxy-4-methoxybenzophenone, 1,7-dihydroxyxanthone and eight triterpenoids, garcihombronane B, D, E and F, friedelin, glutin-5-en-3β-ol, stigmasterol and lupeol. The structures of the compounds were elucidated by spectroscopic methods. The compounds were evaluated for their ability to inhibit copper-mediated LDL oxidation and arachidonic acid (AA)-, adenosine diphosphate (ADP)-, collagen-induced platelet aggregation in vitro. Among the compounds tested, 3,5,3',5'-tetrahydroxy-4-methoxybenzophenone and 1,7-dihydroxyxanthone showed strong inhibitory activity on LDL oxidation with half-maximal inhibitory concentration (IC(50)) values of 6.6 and 1.7 µM, respectively. 3,5,3',5'-Tetrahydroxy-4-methoxybenzophenone exhibited strong activity on AA-, ADP- and collagen-induced platelet aggregation with IC(50) values of 53.6, 125.7 and 178.6 µM, respectively, while 1,7 dihydroxyxanthone showed significant and selective inhibitory activity against ADP-induced aggregation with IC(50) value of 5.7 µM. Of the triterpenoids tested, garcihombronane B showed moderate activity against LDL oxidation and garcihombronane D and F showed selective inhibition on ADP-induced platelet aggregation.
    Matched MeSH terms: Antioxidants/pharmacology*
  7. Chemical composition and antioxidant properties of candlenut oil extracted by supercritical CO2
    Siddique BM, Ahmad A, Alkarkhi AF, Ibrahim MH, K MO
    J Food Sci, 2011 May;76(4):C535-42.
    PMID: 22417332 DOI: 10.1111/j.1750-3841.2011.02146.x
    Candlenut oil was extracted using supercritical CO(2) (SC-CO(2)) with an optimization of parameters, by the response surface methodology. The ground candlenut samples were treated in 2 different ways, that is, dried in either a heat oven (sample moisture content of 2.91%) or dried in a vacuum oven (sample moisture content of 1.98%), before extraction. An untreated sample (moisture content of 4.87%) was used as a control. The maximum percentage of oil was extracted from the heat-oven-dried sample (77.27%), followed by the vacuum-oven-dried sample (74.32%), and the untreated sample (70.12%). At an SC-CO(2) pressure of 48.26 Mpa and 60 min of extraction time, the optimal temperatures for extraction were found to be 76.4 °C, 73.9 °C, and 70.6 °C for the untreated, heat-oven-dried, and vacuum-oven-dried samples, respectively. The heat-oven-dried sample contains the highest percentage of linoleic acid, followed by the untreated and vacuum-oven-dried samples. The antiradical activity of candlenut oil corresponded to an IC(50) value of 30.37 mg/mL.
    Matched MeSH terms: Antioxidants/chemistry*
  8. Fulltext Impact of elevated carbon dioxide on primary, secondary metabolites and antioxidant responses of Eleais guineensis Jacq. (oil palm) seedlings
    Ibrahim MH, Jaafar HZ
    Molecules, 2012;17(5):5195-211.
    PMID: 22628041 DOI: 10.3390/molecules17055195
    A split plot 3 by 3 experiment was designed to investigate the relationships among production of primary metabolites (soluble sugar and starch), secondary metabolites (total flavonoids, TF; total phenolics, TP), phenylalanine lyase (PAL) activity (EC 4.3.1.5), protein and antioxidant activity (FRAP) of three progenies of oil palm seedlings, namely Deli AVROS, Deli Yangambi and Deli URT, under three levels of CO₂ enrichment (400, 800 and 1,200 μmol·mol⁻¹) for 15 weeks of exposure. During the study, the treatment effects were solely contributed by CO₂ enrichment levels; no progenies and interaction effects were observed. As CO₂ levels increased from 400 to 1,200 μmol·mol⁻¹, the production of carbohydrate increased steadily, especially for starch more than soluble sugar. The production of total flavonoids and phenolics contents, were the highest under 1,200 and lowest at 400 μmol·mol⁻¹. It was found that PAL activity was peaked under 1,200 μmol·mol⁻¹ followed by 800 μmol·mol⁻¹ and 400 μmol·mol⁻¹. However, soluble protein was highest under 400 μmol·mol⁻¹ and lowest under 1,200 μmol·mol⁻¹. The sucrose/starch ratio, i.e., the indication of sucrose phosphate synthase actvity (EC 2.4.1.14) was found to be lowest as CO₂ concentration increased from 400 > 800 > 1,200 μmol·mol⁻¹. The antioxidant activity, as determined by the ferric reducing/antioxidant potential (FRAP) activity, increased with increasing CO₂ levels, and was significantly lower than vitamin C and α-tocopherol but higher than butylated hydroxytoluene (BHT). Correlation analysis revealed that nitrogen has a significant negative correlation with carbohydrate, secondary metabolites and FRAP activity indicating up-regulation of production of carbohydrate, secondary metabolites and antioxidant activity of oil palm seedling under elevated CO₂ was due to reduction in nitrogen content in oil palm seedling expose to high CO₂ levels.
    Matched MeSH terms: Antioxidants/metabolism*
  9. Fulltext Antioxidant and antiangiogenic activities of the essential oils of Myristica fragrans and Morinda citrifolia
    Piaru SP, Mahmud R, Abdul Majid AM, Mahmoud Nassar ZD
    Asian Pac J Trop Med, 2012 Apr;5(4):294-8.
    PMID: 22449521 DOI: 10.1016/S1995-7645(12)60042-X
    OBJECTIVE: Toinvestigate the anti-angiogenic activity and antioxidant properties of Myristica fragrans (M. fragrans) (nutmeg) and Morinda citrifolia (M. citrifolia)(mengkudu) oils.

    METHODS: The nutmeg and megkudu essential oils were obtained by steam distillation. The antioxidant activities of both essential oils were determined by beta-carotene/linoleic acid bleaching assay and reducing power while the anti-angiogenic activity was investigated using rat aortic ring assay using various concentrations.

    RESULTS: The results showed that nutmeg oil has higher antioxidant activity than mengkudu oil. The nutmeg oil effectively inhibited the oxidation of linoleic acid with (88.68±0.1)% while the inhibition percentage of oxidation of linoleic acid of the mengkudu oil is (69.44±0.4)%. The nutmeg oil and mengkudu oil showed reducing power with an EC(50) value of 181.4 μg/mL and 3 043.0 μg/mL, respectively. The antiangiogenic activity of nutmeg oil showed significant antiangiogenic activity with IC(50) of 77.64 μg/mL comparing to mengkudu oil which exhibits IC(50) of 109.30 μg/mL.

    CONCLUSIONS: Bioactive compound(s) will be isolated from the nutmeg essential oil to be developed as antiangiogenic drugs.

    Matched MeSH terms: Antioxidants/pharmacology*
  10. The phytochemical content and antimicrobial activities of Malaysian Calophyllum canum (stem bark)
    Alkhamaiseh SI, Taher M, Ahmad F, Qaralleh H, Althunibat OY, Susanti D, et al.
    Pak J Pharm Sci, 2012 Jul;25(3):555-63.
    PMID: 22713941
    Recently there was huge increase in using of 'herbal products'. These can be defined as plants, parts of plants or extracts from plants that are used for curing disease. However, Calophyllum species is a tropical plant and it has been used in traditional medicine, the limitation in safety and effectiveness information could lead to serious health problems. Providing information for communities by evaluating the phytochemical contents, antioxidant, antimicrobial and cytotoxic activities will improve the therapeutic values. Three main Calophyllum canum fractions (none - high polar) were tested to find out the phenolic, flavonoid, flavonol content, DPPH radical scavenging, reducing power and chelating iron ions. Also were tested against Bacillus cereus, Staphylococcus aureus, Escherichia coli, Psedomonas aeruginosa, Candida albicans, and Cryptococcus neoformans. In addition, cytotoxic activity was assayed against lung cancer A549 cell line. The methanol fraction showed no bioactivity but achieved the highest amount of phenolic, flavonol and flavonoid contents, also it showed a significant result as antioxidant, reducing power and chelating agent. The n-hexane fraction achieved the minimum inhibitory concentration (MIC) value 12.5 μg. mL(-1) against B. cereus while the MIC value for DCM fraction was 25 μg. mL(-1). The DCM fraction was more active against S. aureus where the result was 50 μg. mL(-1) while the n-hexane fraction was 100 μg. mL(-1). The three main fractions have shown no activity against gram negative bacterial and fungal. The n-hexane and DCM fractions have shown cytotoxicity against lung cancer cell line; the 50% inhibition concentration (IC(50)) was 22 ± 2.64 and 32 ± 3.78 μg. mL(-1) respectively. The results were statistically significant (P < 0.05). Among the results, C. canum fractions proved to be effective against gram positive bacterial and anti-proliferation activity. Also it showed antioxidant activity as well. The results provided beneficial information for communities as well as can help to search for alternative drugs, and will contribute to establish safe and effective use of phytomedicines in the treatment of diseases.
    Matched MeSH terms: Antioxidants/pharmacology
  11. Fulltext Effect of acid and base catalyzed hydrolysis on the yield of phenolics and antioxidant activity of extracts from germinated brown rice (GBR)
    Sani IM, Iqbal S, Chan KW, Ismail M
    Molecules, 2012 Jun 19;17(6):7584-94.
    PMID: 22713349 DOI: 10.3390/molecules17067584
    The influence of both acidic and basic hydrolysis on the yield, total phenolic content and antioxidative capacity of methanolic extract of germinated brown rice (GBR) was studied. Total phenolic content (TPC), total flavonoid content (TFC), 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) radical cation scavenging, and ferric reducing antioxidant power (FRAP) tests were used for the measurement of antioxidant ability. There was a significant difference p < 0.05) in the TPC and DPPH radical scavenging assay results when comparing neutral with acidic and basic catalysed hydrolysis. The yield of the crude extract was slightly higher in acidic hydrolysis than in basic hydrolysis p > 0.05). The TPC and TFC were highest in acidic hydrolysis. A significant correlation was observed between ABTS radical cation scavenging and FRAP. The antioxidant activity measured using DPPH radical scavenging assay showed high activity in acidic hydrolysis, while the ABTS radical cationscavenging activity and FRAP showed the highest values in basic hydrolysis. The samples were further evaluated using HPLC to determine the individual phenolic concentrations in different hydrolytic media contributing to the antioxidant effects. This study revealed that acidic and basic hydrolysis can improve the yield, phenolic content, and antioxidant activity of germinated brown rice.
    Matched MeSH terms: Antioxidants/chemistry*
  12. Tocotrienol rich fraction (TRF) supplementation protects against oxidative DNA damage and improves cognitive functions in Wistar rats
    Taridi NM, Yahaya MF, Teoh SL, Latiff AA, Ngah WZ, Das S, et al.
    Clin Ter, 2011;162(2):93-8.
    PMID: 21533313
    Oxidative stress is caused by imbalance between the productions of reactive oxygen species (ROS) and antioxidant defense mechanisms. Palm oil antioxidants such as tocotrienol rich fraction (TRF) is known to have neuroprotective effects on neurones by acting against free radical induced neuronal cell death. This study was undertaken to elucidate the effect of TRF on oxidative DNA damage and cognitive functions in experimental rats.
    Matched MeSH terms: Antioxidants/pharmacology*
  13. Oxidative stability of sunflower oil supplemented with medicinal split gill mushroom, Schizophyllum commune Fr.:Fr. extract during accelerated storage
    Yim HS, Chye FY, Heng PY, Ho CW
    Int J Med Mushrooms, 2011;13(4):357-68.
    PMID: 22164766
    The oxidative stability of sunflower oil supplemented with medicinal split gill mushroom, Schizophyllum commune's crude extract (CE), the formic acid (FA) fraction and semipurified subfractions (SF) II and IV were tested, compared to BHA and alpha-tocopherol, by measuring their peroxide value, iodine value, p-anisidine value, thiobarbituric acid-reactive substances, and free fatty acid content. Their total phenolic content (TPC), 2,2-diphenyl-1-picryhydrazyl (DPPH) radical scavenging, and ferric reducing/antioxidant power (FRAP) were also evaluated. FA and CE exhibited highest DPPH* scavenging, while FA and SFIV showed the highest FRAP; TPC was found to be highest in CE, FA, and SFIV. BHA and alpha-tocopherol are more protective in stabilizing the sunflower oil; SFII and SFIV had short-term protective effect in secondary oxidation for 1 year, while CE and FA retarded secondary oxidation and extended the shelf life 1 1/2 years and 2 years, respectively. HPLC-DAD analysis found (+)-catechin in Sch. commune's extracts. Sch. commune's extracts did not show similar retardation of lipid oxidation in sunflower oil as compared to alpha-tocopherol and BHA at the 200 ppm level. However, the higher concentration of Sch. commune's extract that provided the protective effect in stabilizing sunflower oil can be further studied.
    Matched MeSH terms: Antioxidants/chemistry*
  14. Comparative study of antioxidant activities and total phenolic content of selected edible wild mushrooms
    Yim HS, Chye FY, Lee MY, Matanjun P, How SE, Ho CW
    Int J Med Mushrooms, 2011;13(3):245-55.
    PMID: 22135876
    The present study aims to assess the antioxidant activities (AOA) and total phenolic content (TPC) of water extracts of selected edible wild mushrooms: Pleurotus porrigens, Schizophyllum commune, Hygrocybe conica, and Lentinus ciliatus. The AOA were evaluated against DPPH radical and ABTS radical cation scavenging ability, ferric-reducing antioxidant power (FRAP) and beta-carotene-linoleate bleaching (beta-CB) assays, and the Folin-Ciocalteu method for TPC. BHA was used as reference. P. porrigens showed significantly higher (p < 0.05) DPPH* scavenging ability (90.78 +/- 0.30%) and FRAP (6.37 +/- 0.22 mM FE/100g), while Sch. commune showed significantly higher (p < 0.05) ABTS*+ inhibition activity (94.96 +/- 0.70%) and beta-CB inhibition activity (94.18 +/- 0.17%), respectively. TPC was found in a descending order of P. poriggens > L. ciliatus = Pleurotus ostreatus (cultivated) > H. conica = Sch. commune. Positive correlation was observed between the AOA and TPC. When compared to BHA (2 mM), P. porrigens showed significantly higher (p < 0.05) DPPH* scavenging ability and reducing power, while Sch. commune showed comparable DPPH* scavenging ability and ABTS*+ inhibition activity. All the mushrooms have better ABTS*+ inhibition activity than BHA (1 mM). The beta-CB inhibition activity of BHA was significantly higher than those of edible wild mushrooms. The water extracts of edible wild mushrooms showed potent antioxidant activities compared to BHA to a certain extent.
    Matched MeSH terms: Antioxidants/pharmacology*
  15. A review of fish-derived antioxidant and antimicrobial peptides: their production, assessment, and applications
    Najafian L, Babji AS
    Peptides, 2012 Jan;33(1):178-85.
    PMID: 22138166 DOI: 10.1016/j.peptides.2011.11.013
    Fishes are rich sources of structurally diverse bioactive compounds. In recent years, much attention has been paid to the existence of peptides with biological activities and proteins derived from foods that might have beneficial effects for humans. Antioxidant and antimicrobial peptides isolated from fish sources may be used as functional ingredients in food formulations to promote consumer health and improve the shelf life of food products. This paper presents an overview of the antioxidant and antimicrobial peptides derived from various fishes. In addition, we discuss the extraction of fish proteins, enzymatic production, and the techniques used to isolate and characterize these compounds. Furthermore, we review the methods used to assay the bioactivities and their applications in food and nutraceuticals.
    Matched MeSH terms: Antioxidants/pharmacology*
  16. Identification and quantification of phenolic compounds in bambangan (Mangifera pajang Kort.) peels and their free radical scavenging activity
    Hassan FA, Ismail A, Abdulhamid A, Azlan A
    J Agric Food Chem, 2011 Sep 14;59(17):9102-11.
    PMID: 21800901 DOI: 10.1021/jf201270n
    Phenolic compounds and antioxidant capacity of acidified methanolic extract prepared from fully ripe bambangan (Mangifera pajang K.) peel cultivated in Sarawak, Malaysia, were analyzed. The total phenolic content (98.3 mg GAE/g) of bambangan peel powder (BPP) was determined by the Folin-Ciocalteu method. BPP showed a strong potency of antioxidant activity and was consistent with that of BHT and vitamin C as confirmed by the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity and FRAP (ferric-reducing antioxidant power) assays. Gallic acid, p-coumaric acid, ellagic acid, protocatechuic acid, and mangiferin were the major compounds among the 16 phenolics that have been identified and quantified in M. pajang peels with 20.9, 12.7, 7.3, 5.4, and 4.8 mg/g BPP, respectively. Peak identities were confirmed by comparing their retention times, UV-vis absorption spectra, and mass spectra with authentic standards. The 16 phenolic compounds identified in M. pajang K. using HPLC-DAD and TSQ-ESI-MS are reported here for the first time.
    Matched MeSH terms: Antioxidants/pharmacology
  17. Low dose of tocotrienols protects osteoblasts against oxidative stress
    Nizar AM, Nazrun AS, Norazlina M, Norliza M, Ima Nirwana S
    Clin Ter, 2011;162(6):533-8.
    PMID: 22262323
    Vitamin E is an antioxidant that may protect bone against oxidative stress-induced osteoporosis. This in vitro study was conducted to determine the protective effects of a-tocopherol and γ-tocotrienol on osteoblasts, the bone forming cells, against oxidative stress.
    Matched MeSH terms: Antioxidants/administration & dosage*
  18. Fulltext Antioxidant activity and phytochemical screening of the methanol extracts of Euphorbia hirta L
    Basma AA, Zakaria Z, Latha LY, Sasidharan S
    Asian Pac J Trop Med, 2011 May;4(5):386-90.
    PMID: 21771682 DOI: 10.1016/S1995-7645(11)60109-0
    OBJECTIVE: To assess antioxidant activities of different parts of Euphorbia hirta (E. hirta), and to search for new sources of safe and inexpensive antioxidants.

    METHODS: Samples of leaves, stems, flowers and roots from E. hirta were tested for total phenolic content, and flavonoids content and in vitro antioxidant activity by diphenyl-1-picrylhydrazyl (DPPH) assay and reducing power was measured using cyanoferrate method.

    RESULTS: The leaves extract exhibited a maximum DPPH scavenging activity of (72.96±0.78)% followed by the flowers, roots and stems whose scavenging activities were (52.45±0.66)%, (48.59±0.97)%, and (44.42±0.94)%, respectively. The standard butylated hydroxytoluene (BHT) was (75.13±0.75)%. The IC(50) for leaves, flowers, roots, stems and BHT were 0.803, 0.972, 0.989, 1.358 and 0.794 mg/mL, respectively. The reducing power of the leaves extract was comparable with that of ascorbic acid and found to be dose dependent. Leaves extract had the highest total phenolic content [(206.17±1.95) mg GAE/g], followed by flowers, roots and stems extracts which were (117.08±3.10) mg GAE/g, (83.15±1.19) mg GAE/g, and (65.70±1.72) mg GAE/g, respectively. On the other hand, total flavonoids content also from leave had the highest value [(37.970±0.003) mg CEQ/g], followed by flowers, roots and stems extracts which were (35.200±0.002) mg CEQ/g, (24.350±0.006) mg CEQ/g, and (24.120±0.004) mg CEQ/g, respectively. HPTLC bioautography analysis of phenolic and antioxidant substance revealed phenolic compounds. Phytochemical screening of E. hirta leaf extract revealed the presence of reducing sugars, terpenoids, alkaloids, steroids, tannins, flavanoids and phenolic compounds.

    CONCLUSIONS: These results suggeste that E. hirta have strong antioxidant potential. Further study is necessary for isolation and characterization of the active antioxidant agents, which can be used to treat various oxidative stress-related diseases.

    Matched MeSH terms: Antioxidants/pharmacology*
  19. Identification of proanthocyanidin dimers and trimers, flavone C-Glycosides, and antioxidants in Ficus deltoidea , a malaysian herbal tea
    Omar MH, Mullen W, Crozier A
    J Agric Food Chem, 2011 Feb 23;59(4):1363-9.
    PMID: 21261251 DOI: 10.1021/jf1032729
    Phenolic compounds in an aqueous infusion of leaves of Ficus deltoidea (Moraceae), a well-known herbal tea in Malaysia, were analyzed by HPLC coupled to photodiode array and fluorescence detectors and an electrospray ionization tandem mass spectrometer. Following chromatography of extracts on a reversed phase C(12) column, 25 flavonoids were characterized and/or tentatively identified with the main constituents being flavan-3-ol monomers, proanthocyanidins, and C-linked flavone glycosides. The proanthocyanidins were dimers and trimers comprising (epi)catechin and (epi)afzelechin units. No higher molecular weight proanthocyanidin polymers were detected. The antioxidant activity of F. deltoidea extract was analyzed using HPLC with online antioxidant detection. This revealed that 85% of the total antioxidant activity of the aqueous F. deltoidea infusion was attributable to the flavan-3-ol monomers and the proanthocyanidins.
    Matched MeSH terms: Antioxidants/analysis*
  20. Fulltext Antioxidant and hepatoprotective effects of Murdannia bracteata methanol extract
    Yam MF, Ang LF, Lim CP, Ameer OZ, Salman IM, Ahmad M, et al.
    J Acupunct Meridian Stud, 2010 Sep;3(3):197-202.
    PMID: 20869021 DOI: 10.1016/S2005-2901(10)60036-2
    Murdannia bracteata (C. B. Clarke) is a local plant that is widely used in Malaysia as a traditional remedy for various diseases of the kidney and liver, including inflammation and cancer. In the present study, we investigated the antioxidant and hepatoprotective activities of M. bracteata methanol extract (MB). 2,2'-diphenyl-1-picrylhydrazyl radical scavenging activity, lipid peroxidation inhibition and trolox equivalent antioxidant capacity of MB were determined. The hepatoprotective activity of MB was studied using a CCl(4)-induced liver toxicity model in rats. The hepatoprotective effect was assessed by monitoring the plasma malondialdehyde level and serum alanine transaminase and aspartate transaminase activities. Histopathological changes of hepatic tissue were also investigated. The results indicated that MB possessed potential antioxidant, lipid peroxidation inhibition and free radical scavenging activities. Pretreatment of rats with MB (500 mg/kg and 1000 mg/kg per os) before induction of CCl(4)-induced hepatotoxicity showed a dose-dependent reduction in the necrotic changes in hepatic tissue. The increases in plasma malondialdehyde level, serum alanine transaminase and aspartate transaminase activities were also significantly inhibited by MB. The total phenolic content of MB determined using Folin-Ciocalteu assay was found to be 10%. The results of the present study indicated that the hepatoprotective effect of MB is most likely due to its antioxidant and free radical scavenging properties.
    Matched MeSH terms: Antioxidants/pharmacology*
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