Displaying publications 121 - 140 of 1825 in total

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  1. Multiple molecular targets mediated antioxidant activity, molecular docking, ADMET, QSAR and bioactivity studies of halo substituted urea derivatives of α-Methyl-l-DOPA
    Vadabingi N, Avula VKR, Zyryanov GV, Vallela S, Anireddy JS, Pasupuleti VR, et al.
    Bioorg Chem, 2020 04;97:103708.
    PMID: 32146177 DOI: 10.1016/j.bioorg.2020.103708
    A series of novel α-methyl-l-DOPA urea derivatives viz., 3-(3,4-dihydroxyphenyl)-2-methyl-2-(3-halo/trifluoromethyl substituted phenyl ureido)propanoic acids (6a-e) have been synthesized from the reaction of α-methyl-l-DOPA (3) with various aryl isocyanates (4a-e) by using triethylamine (5, TEA) as a base catalyst in THF at reflux conditions. The synthesized compounds are structurally characterized by spectral (IR, 1H &13C NMR and MASS) and elemental analysis studies and screened for their in-vitro antioxidant activity against DPPH, NO and H2O2 free radical scavenging assays and identified compounds 6c &6d as potential antioxidants. The acquired in vitro results were correlated with the results of molecular docking, ADMET, QSAR and bioactivity studies performed for them and predicted that the recorded in silico binding affinities are in good correlation with the in vitro antioxidant activity results. The molecular docking analysis has comprehended the strong hydrogen bonding interactions of 6a-e with 1CB4, 1N8Q, 3MNG, 1OG5, 1DNU, 3NRZ, 2CDU, 1HD2 and 2HCK proteins of their respective SOD, LO, PRXS5, CP450, MP, XO, NO, PRY5 and HCK enzymes. This has sustained the effective binding of 6a-e and resulted in functional inhibition of selective aminoacid residues to be pronounced as multiple molecular targets mediated antioxidant potent compounds. In addition, the evaluated toxicology risks of 6a-e are identified with in the potential limits of drug candidates. The conformational analysis of 6c & 6d prominently infers that urea moiety uniting α-methyl-l-DOPA with halo substituted aryl units into a distinctive orientation to comply good structure-activity to inhibit the proliferation of reactive oxygen species in vivo.
    Matched MeSH terms: Antioxidants/pharmacokinetics; Antioxidants/pharmacology*; Antioxidants/chemistry*
  2. Fulltext Optimization of an Ultrasound-Assisted Extraction Condition for Flavonoid Compounds from Cocoa Shells (Theobroma cacao) Using Response Surface Methodology
    Md Yusof AH, Abd Gani SS, Zaidan UH, Halmi MIE, Zainudin BH
    Molecules, 2019 Feb 16;24(4).
    PMID: 30781448 DOI: 10.3390/molecules24040711
    This study investigates the ultrasound-assisted extraction of flavonoids from Malaysian cocoa shell extracts, and optimization using response surface methodology. There are three variables involved in this study, namely: ethanol concentration (70⁻90 v/v %), temperature (45⁻65 °C), and ultrasound irradiation time (30⁻60 min). All of the data were collected and analyzed for variance (ANOVA). The coefficient of determination (R²) and the model was significant in interaction between all variables (98% and p < 0.0001, respectively). In addition, the lack of fit test for the model was not of significance, with p > 0.0684. The ethanol concentration, temperature, and ultrasound irradiation time that yielded the maximum value of the total flavonoid content (TFC; 7.47 mg RE/g dried weight (DW)) was 80%, 55 °C, and 45 min, respectively. The optimum value from the validation of the experimental TFC was 7.23 ± 0.15 mg of rutin, equivalent per gram of extract with ethanol concentration, temperature, and ultrasound irradiation time values of 74.20%, 49.99 °C, and 42.82 min, respectively. While the modelled equation fits the data, the T-test is not significant, suggesting that the experimental values agree with those predicted by the response surface methodology models.
    Matched MeSH terms: Antioxidants/analysis; Antioxidants/isolation & purification; Antioxidants/chemistry
  3. Understanding of the Role of Pretreatment Methods on Rapeseed Oil from the Perspective of Phenolic Compounds
    Xu YJ, Jiang F, Song J, Yang X, Shu N, Yuan L, et al.
    J Agric Food Chem, 2020 Aug 19;68(33):8847-8854.
    PMID: 32806128 DOI: 10.1021/acs.jafc.0c03539
    The thermal pretreatment of oilseed prior to oil extraction could increase the oil yield and improve the oil quality. Phenolic compounds are important antioxidants in rapeseed oil. In this study, we investigated the impact of thermal pretreatment method on the rapeseed oil based on phenolic compound levels. Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) analysis showed that the phenolic compound contents in the microwave-pretreated oil were higher than those in the oven- and infrared-treated oils. Sinapic acid (SA) and canolol (CA), which are the top two phenolic compounds in rapeseed oil, exerted well 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity with IC50 values of 8.45 and 8.80 μmol/L. The cell experiment uncovered that SA and CA have significant biological activities related to rapeseed oil quality, including increase of antioxidant enzymes superoxide dismutase (SOD), alleviation of reactive oxygen species (ROS), and cytotoxicity of HepG2 cells after the intake of excessive oleic acid. Further investigation indicated that SA and CA reduced cell apoptosis rate through Bax-Bcl-2-caspase-3 and p53-Bax-Bcl-2-caspase-3, respectively. Taken together, our findings suggest that microwave pretreatment is the best method to improve the content of phenolic compounds in rapeseed oil compared with oven and infrared pretreatments.
    Matched MeSH terms: Antioxidants/isolation & purification; Antioxidants/pharmacology; Antioxidants/chemistry
  4. Fulltext Statistical Optimization of Flavonoid and Antioxidant Recovery from Macerated Chinese and Malaysian Lotus Root (Nelumbo nucifera) Using Response Surface Methodology
    Tan SJ, Lee CK, Gan CY, Olalere OA
    Molecules, 2021 Apr 01;26(7).
    PMID: 33916148 DOI: 10.3390/molecules26072014
    In this study, the combination of parameters required for optimal extraction of anti-oxidative components from the Chinese lotus (CLR) and Malaysian lotus (MLR) roots were carefully investigated. Box-Behnken design was employed to optimize the pH (X1: 2-3), extraction time (X2: 0.5-1.5 h) and solvent-to-sample ratio (X3: 20-40 mL/g) to obtain a high flavonoid yield with high % DPPHsc free radical scavenging and Ferric-reducing power assay (FRAP). The analysis of variance clearly showed the significant contribution of quadratic model for all responses. The optimal conditions for both Chinese lotus (CLR) and Malaysian lotus (MLR) roots were obtained as: CLR: X1 = 2.5; X2 = 0.5 h; X3 = 40 mL/g; MLR: X1 = 2.4; X2 = 0.5 h; X3 = 40 mL/g. These optimum conditions gave (a) Total flavonoid content (TFC) of 0.599 mg PCE/g sample and 0.549 mg PCE/g sample, respectively; (b) % DPPHsc of 48.36% and 29.11%, respectively; (c) FRAP value of 2.07 mM FeSO4 and 1.89 mM FeSO4, respectively. A close agreement between predicted and experimental values was found. The result obtained succinctly revealed that the Chinese lotus exhibited higher antioxidant and total flavonoid content when compared with the Malaysia lotus root at optimum extraction condition.
    Matched MeSH terms: Antioxidants/isolation & purification*; Antioxidants/pharmacology; Antioxidants/chemistry*
  5. Metabolomic analysis reveals the valuable bioactive compounds of Ardisia elliptica
    Wong PL, Ramli NS, Tan CP, Azlan A, Abas F
    Phytochem Anal, 2021 Sep;32(5):685-697.
    PMID: 33295100 DOI: 10.1002/pca.3015
    INTRODUCTION: Ardisia elliptica Thunb. (Primulaceae) is a medicinal herb that is traditionally used for the treatment of fever, diarrhoea, measles and herpes. However, there is limited information regarding the correlation of its phytoconstituents with the bioactivity. Optimisation of solvent extraction is vital for maximising retention of bioactive molecules.

    OBJECTIVE: This study investigated the metabolite variations in A. elliptica leaves and the correlation with antioxidant activities.

    METHODOLOGY: Total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and nitric oxide (NO) radicals scavenging assays were performed on A. elliptica leaves extracted with four different ethanol ratios (0%, 50%, 70% and absolute ethanol). The correlation of metabolites with antioxidant activities was evaluated using a nuclear magnetic resonance (NMR)-based metabolomics approach.

    RESULTS: The results showed that the 50% and 70% ethanolic extracts retained the highest TPC, and the 70% ethanolic extract was the most active, exhibiting half maximal inhibitory concentration (IC50 ) values of 10.18 ± 0.83 and 43.05 ± 1.69 μg/mL, respectively, in both radical scavenging assays. A total of 46 metabolites were tentatively identified, including flavonoids, benzoquinones, triterpenes and phenolic derivatives. The 50% and 70% ethanolic extracts showed similarities in metabolites content and were well discriminated from water and absolute ethanol extracts in a principal component analysis (PCA) model. Moreover, 31 metabolites were found to contribute significantly to the differentiation and antioxidant activity.

    CONCLUSION: This study provides information on bioactive compounds in A. elliptica leaves, which is promising as a functional ingredient for food production or for the development of phytomedicinal products.

    Matched MeSH terms: Antioxidants
  6. Optimisation of microwave-assisted extraction and functional elucidation of bioactive compounds from Cola nitida pod
    Olalere OA, Gan CY, Akintomiwa OE, Adeyi O, Adeyi A
    Phytochem Anal, 2021 Sep;32(5):850-858.
    PMID: 33583076 DOI: 10.1002/pca.3030
    INTRODUCTION: The quality characteristics and stability of phenolic by-products from Cola nitida wastes are critical factors for drug formulation and food nutraceutical applications.

    OBJECTIVES: In this study, the effect of electromagnetic-based microwave-reflux extraction on the total phenolic content, antioxidant capacity, morphological characteristics, physisorption and chromatographic phenolic profiles were successfully investigated. These physicochemical analyses are often employed in the standardisation of dried herbal and food nutraceutical products.

    MATERIAL AND METHODS: In this study, the electromagnetic-based extraction process was optimised using the Box-Behnken design. The oleoresin bio-products were subsequently characterised to determine the total phenolic content, morphological and microstructural degradation. These analyses were conducted to elucidate the effect of the microwave heating on the C. nitida pod powder.

    RESULTS: From the predicted response, the optimal percentage yield was achieved at 26.20% under 5.39 min of irradiation time, 440 W microwave power and oven temperature of 55°C. Moreover, the rapid estimation of the phenolic content and antioxidant capacity were recorded at 124.84 ± 0.064 mg gallic acid equivalent (GAE)/g dry weight (d.w.) and 6.93 ± 0.34 μg/mL, respectively. The physicochemical characterisation results from the Fourier-transform infrared spectroscopy, field emission scanning electron microscopy and physisorption analyses showed remarkable changes in the micro-surface area (13.66%) characteristics.

    CONCLUSION: The recorded optimal conditions established a basis for future scale-up of microwave extraction parameters with a potential for maximum yield. The physiochemical characterisation revealed the functional characteristics of C. nitida and their tolerance to microwave heating.

    Matched MeSH terms: Antioxidants
  7. Natural anti-aging skincare: role and potential
    Ahmed IA, Mikail MA, Zamakshshari N, Abdullah AH
    Biogerontology, 2020 06;21(3):293-310.
    PMID: 32162126 DOI: 10.1007/s10522-020-09865-z
    The deterioration of the skin morphology and physiology is the first and earliest obvious harbinger of the aging process which is progressively manifested with increasing age. Such deterioration affects the vital functions of the skin such as homeodynamic regulation of body temperature, fluid balance, loss of electrolytes and proteins, production of vitamin D, waste removal, immune surveillance, sensory perception, and protection of other organs against deleterious environmental factors. There are, however, harmful chemicals and toxins found in everyday cosmetics that consumers are now aware of. Thus, the natural beauty industry is on the rise with innovative technology and high-performance ingredients as more consumers demand healthier options. Therefore, the aims of this review are to give some critical insights to the effects of both intrinsic and extrinsic factors on excessive or premature skin aging and to elaborate on the relevance of natural beauty and natural anti-aging skincare approaches that will help consumers, scientists and entrepreneurs make the switch. Our recent investigations have shown the potential and relevance of identifying more resources from our rich natural heritage from various plant sources such as leaves, fruits, pomace, seeds, flowers, twigs and so on which can be explored for natural anti-aging skincare product formulations. These trending narratives have started to gain traction among researchers and consumers owing to the sustainability concern and impact of synthetic ingredients on human health and the environment. The natural anti-aging ingredients, which basically follow hormetic pathways, are potentially useful as moisturizing agents; barrier repair agents; antioxidants, vitamins, hydroxy acids, skin lightening agents, anti-inflammatory ingredients, and sunblock ingredients.
    Matched MeSH terms: Antioxidants
  8. Antioxidant properties of methanolic extract of Canarium odontophyllum fruit
    Azrina, A., Nurul Nadiah, M.N., Amin, I.
    International Food Research Journal, 2010;17(2):319-326.
    MyJurnal
    The antioxidant properties of skin, flesh and kernel of Canarium odontophyllum fruit were determined. The methanolic extracts of the fruit were screened for their total phenolic content and antioxidant properties. The averaged antioxidant properties (mM TE/g FM) in skin, flesh, and kernel of Canarium odontophyllum were 16.46 ± 0.24, 20.54 ± 0.35, and 8.89 ± 0.29, respectively by DPPH assay; 151.24 ± 9.75, 70.58 ± 2.98, and 5.65 ± 0.02, respectively by FRAP assay; and 47.9 ± 0.00, 11.61 ± 1.14, and 3.00 ± 0.00, respectively by β-Carotene bleaching method. The averaged OH scavenging activity (mg DMSOE/mg FM) in skin, flesh, and kernel of Canarium odontophyllum were 43.33 ± 13.85, 7.81 ± 1.42, and 3.31 ± 0.80, respectively. While averaged total phenolic content (mg GAE/100g FM) were 387.5 ± 33.23, 267.0 ± 4.24, and 51.0 ± 0.00 for skin, flesh, and kernel respectively. Antioxidant activities were positively correlated with the total phenolic content (0.71 ≤ r ≤ 0.84).
    Matched MeSH terms: Antioxidants
  9. Fulltext Effect of different extraction techniques on total phenolic content and antioxidant activity of Quercus infectoria galls
    Hasmida, M.N., Nur Syukriah, A.R., Liza, M.S., Mohd Azizi, C.Y.
    International Food Research Journal, 2014;21(3):1075-1079.
    MyJurnal
    In this work, the bioactive compounds which was obtained by extracting Quercus infectoria via two extraction methods; Soxhlet and supercritical carbon dioxide (SC-CO2) extraction, were analyzed using total phenolic content and DPPH (2,2-diphenyl-1-picryl hydrazyl) free radical scavenging activity analysis. The aim of this study is to compare the total phenolic content and antioxidant activity of Quercus infectoria extract acquired from SC-CO2 extraction with those from Soxhlet extraction method. The results showed the used of SC-CO2 extraction give the lowest extraction yield as compared to Soxhlet extraction. The selectivity of Q. infectoria extracts using SC-CO2 extraction was better which in contrast with Soxhlet extraction method since it shows higher total phenolic content (143.75 ± 1.06 mg GAE/g sample). This study also revealed that the extracts from both extraction methods can posses’ antioxidant activity and comparable to those obtained from commercial antioxidant.
    Matched MeSH terms: Antioxidants
  10. Fulltext Optimisation of extraction conditions for phenolic compounds from limau purut (Citrus hystrix) peels
    Chan, S.W., Lee, C.Y., Yap, C.F., Wan Aida, W.M., Ho, C.W.
    International Food Research Journal, 2009;16(2):203-213.
    MyJurnal
    The objective of this study was to optimise the extraction conditions for phenolic compounds from limau purut (Citrus hystrix) peels using response surface methodology (RSM). A central composite rotatable design (CCRD) was applied to determine the effects of ethanol concentration (%), extraction temperature (oC), and extraction time (min) on total phenolic content (TPC) from limau purut (Citrus hystrix) peels. The independent variables were coded at five levels and their actual values were selected based on the results of single factor experiments. Results showed that ethanol concentration was the most significant (p
    Matched MeSH terms: Antioxidants
  11. Fulltext Effect of solid-to-solvent ratio on phenolic content and antioxidant capacities of “Dukung Anak” (Phyllanthus niruri)
    Wong, B.Y., Tan, C.P., Ho, C.W.
    International Food Research Journal, 2013;20(1):325-330.
    MyJurnal
    The objective of this study was to evaluate the effects of solid-to-solvent ratio (1:5. 1:10, 1:15 and 1:20) on the extraction of phenolic compounds (TPC and TFC) and antioxidant capacity (ABTS and DPPH radical scavenging capacity) of P. niruri. Solid-to-solvent ratio showed a significant effect for both phenolic compounds (TPC and TFC) and antioxidant capacity (ABTS and DPPH radical scavenging capacity) with 1:20 was the condition for extracting the highest of phenolic compounds (TPC and TFC) with a value of 5788.7 mg GAE/100 g DW and 1906.5 mg CE/100 g DW, respectively and exhibited high antioxidant capacities (ABTS and DPPH radical scavenging capacities) with a value of 0.820 mM and 1.598 mM, respectively among the four levels studied. TPC was positively and significantly correlated with ABTS and DPPH (r=0.999 and r=0.999) under the effects of solid-to-solvent ratio as compared to TFC, positively and strongly correlated (r=0.865 and r=0.868) with ABTS and DPPH.
    Matched MeSH terms: Antioxidants
  12. Fulltext Stability of selected quality attributes of pink guava juice during storage at elevated temperatures
    Aishah, B., Hannah, K., Zati Alyani, O.
    International Food Research Journal, 2016;23(5):1918-1925.
    MyJurnal
    Quality degradation is normally judge by monitoring independently the loss of a certain quality
    attribute during storage. However, the rate of degradation for each of the quality attributes
    present in a food product is not the same. This study focus on deterioration of vitamin C,
    lycopene, total phenolics and antioxidant activity of ready-to-drink pink guava juice (PGJ)
    during storage at elevated temperatures. Kinetic order, rate constant (k), activation energy
    (Ea) and temperature coefficient (Q10) of the degradation were derived by applying Arrhenius
    equation. The results obtained showed that freshly made PGJ contain 39.79±2.18 mg/100 mL
    of vitamin C, 3.17±0.27 mg/L of lycopene, 28.08±4.11 mgGAE/100 mL of total phenolic
    content (TPC) and 13.20±1.91 mMTE/100 mL of ferric reducing antioxidant power (FRAP).
    All quality attributes measured in this study showed zero-order kinetic reaction. The results
    also showed that FRAP has the highest Ea of 49.52 KJ/mol and Q10 of 1.80, followed by
    vitamin C (Ea=41.49 KJ/mol; Q10=1.64), lycopene (Ea=31.75 KJ/mol; Q10=1.46), and lastly
    TPC (Ea=14.11 KJ/mol; Q10=1.18). The predicted total depletion of each quality attribute
    at refrigerated storage (5o
    C) were 266 days for antioxidant activity, 158 days for vitamin C
    and lycopene, and 63 days for total phenolics. This study provide useful information on the
    degradation rate and availability of health beneficial and bioactive compounds present in fruit
    juice beverage during storage.
    Matched MeSH terms: Antioxidants
  13. Fulltext Influence of ripening stages on physicochemical characteristics and antioxidant properties of bitter gourd (Momordica charantia)
    Aminah, A., Anna, P.K.
    International Food Research Journal, 2011;18(3):-.
    MyJurnal
    Momordica charantia is known to contain with antioxidant properties and bioactive compounds to lower of diabetic diseases. Objective this study was investigate the influence of ripening stages on the phenolic bioactive substances and the corresponding antioxidant activity of bitter melon (Momordica charantia). The ripening of bitter melon fruit divided to four stages (RS1, RS2, RS3 and RS4). The results of this study were more ripened the fruit, lightness (L * ), yellowish (b * ) and chroma increased. Other ways, more ripened the fruit, the pH value and titratable acidity decreased. Total phenolic content and FRAF of RS 4 was highest compared other samples but DPPH of RS 4 was lowest among all the samples. However DPPH and FRAP value of bitter gourd on ripening stages showed no significant difference (p>0.05) among samples.
    Matched MeSH terms: Antioxidants
  14. Fulltext Apolipoprotein E gene polymorphisms in essential hypertension: a preliminary study with meta-analysis
    Wisam, Nabil lbrahim, Norsidah KZ, Samsul D, Zamzila A, Rafidah HM
    International Medical Journal Malaysia, 2015;14(2):45-52.
    MyJurnal
    Essential hypertension is a multifactorial disease. Many experimental studies have elucidated
    the role of oxidative stress and atherosclerosis in the pathogenesis of essential hypertension. Apolipoprotein
    E is a plasma protein that is found to have antioxidant properties, and it also protects against atherosclerosis.
    Interestingly, the biological function of apolipoprotein E is strongly affected by polymorphisms in its gene.
    Based on this evidence, our aim was to investigate the association of apolipoprotein E gene polymorphisms with
    essential hypertension.
    Matched MeSH terms: Antioxidants
  15. 1H NMR and antioxidant profiles of polar and non-polar extracts of persimmon (Diospyros kaki L.) - Metabolomics study based on cultivars and origins
    Maulidiani M, Mediani A, Abas F, Park YS, Park YK, Kim YM, et al.
    Talanta, 2018 Jul 01;184:277-286.
    PMID: 29674043 DOI: 10.1016/j.talanta.2018.02.084
    Persimmon (Diospyros kaki L.) is one of the most important fruits that has been consumed for its medicinal properties due to the presence of some active metabolites, particularly polyphenols and carotenoids. Previously described methods, including HPLC, were limited in the determination of metabolites in different persimmon varieties. The present study shows the evaluation and the differences among persimmon polar and non-polar extracts by 1H NMR-based metabolomics approach. The hierarchical clustering analysis (HCA) based on score values of principal component analysis (PCA) model was used to analyze the important compounds in investigated fruits. The 1H NMR spectrum of persimmon chloroform (CDCl3) extracts showed different types of compounds as compared to polar methanol-water (CD3OD-D2O) ones. Persimmons growing in Israel were clustered different from those growing in Korea with the abundance of phenolic compounds (gallic, caffeic and protocathecuic acids), carotenoids (β-cryptoxanthin, lutein, and zeaxanthin), amino acids (alanine), maltose, uridine, and fatty acids (myristic and palmitoleic acids). Glucose, choline and formic acid were more prominent in persimmon growing in Korea. In CD3OD-D2O and CDCl3 persimmon extracts, 43 metabolites were identified. The metabolic differences were shown as well on the results of bioactivities and antioxidant capacities determined by ABTS, FRAP, CUPRAC and DPPH assays. The presented methods can be widely used for quantitation of multiple compounds in many plant and biological samples especially in vegetables and fruits.
    Matched MeSH terms: Antioxidants/analysis*; Antioxidants/isolation & purification; Antioxidants/metabolism*
  16. Alzheimer's Disease and Natural Products: Future Regimens Emerging from Nature
    Islam MA, Khandker SS, Alam F, Khalil MI, Kamal MA, Gan SH
    Curr Top Med Chem, 2017;17(12):1408-1428.
    PMID: 28049401 DOI: 10.2174/1568026617666170103163054
    Alzheimer's disease (AD), which largely affects the elderly, has become a global burden. Patients with AD have both short- and long-term memory impairments. The neuronal loss in AD occurs due to abnormally folded amyloid beta proteins and aggregation of hyperphosphorylated tau proteins in the brain. Eventually, amyloid plaques and neurofibrillary tangles are formed, which subsequently disintegrate the neuronal transport system. There are several factors which are involved in AD pathogenesis, including oxidative stress, inflammation and the presence of metal ions. The modern therapies utilized for AD treatment have many adverse effects, driving the quest for more safe and effective medications. Many dietary components, including different types of fruits, vegetables, spices, and marine products as well as a Mediterranean diet, are a good source of antioxidants and have anti-inflammatory properties, with many showing substantial potential against AD pathogenesis. In this review, we discuss the potential of these foods for treating AD and opportunities for developing disease-targeted drugs from active compounds extracted from natural dietary products.
    Matched MeSH terms: Antioxidants/adverse effects; Antioxidants/isolation & purification; Antioxidants/pharmacology*
  17. Current anti-biofilm strategies and potential of antioxidants in biofilm control
    Ong KS, Mawang CI, Daniel-Jambun D, Lim YY, Lee SM
    Expert Rev Anti Infect Ther, 2018 11;16(11):855-864.
    PMID: 30308132 DOI: 10.1080/14787210.2018.1535898
    INTRODUCTION: Biofilm formation is a strategy for microorganisms to adapt and survive in hostile environments. Microorganisms that are able to produce biofilms are currently recognized as a threat to human health. Areas covered: Many strategies have been employed to eradicate biofilms, but several drawbacks from these methods had subsequently raised concerns on the need for alternative approaches to effectively prevent biofilm formation. One of the main mechanisms that drives a microorganism to transit from a planktonic to a biofilm-sessile state, is oxidative stress. Chemical agents that could target oxidative stress regulators, for instance antioxidants, could therefore be used to treat biofilm-associated infections. Expert commentary: The focus of this review is to summarize the function and limitation of the current anti-biofilm strategies and will propose the use of antioxidants as an alternative method to treat, prevent and eradicate biofilms. Studies have shown that water-soluble and lipid-soluble antioxidants can reduce and prevent biofilm formation, by influencing the expression of genes associated with oxidative stress. Further in vivo work should be conducted to ensure the efficacy of these antioxidants in a biological environment. Nevertheless, antioxidants are promising anti-biofilm agents, and thus is a potential solution for biofilm-associated infections in the future.
    Matched MeSH terms: Antioxidants/pharmacology; Antioxidants/therapeutic use*; Antioxidants/chemistry
  18. Response surface methodology optimization for extraction of phenolics and antioxidant capacity in defatted dabai parts
    H-E. Khoo, Azlan A, Ismail A, Abas F
    Sains Malaysiana, 2013;42:949-954.
    This study aimed to determine the total phenolics and antioxidant capacity of defatted dabai parts based on liquid extraction and optimized using response surface methodology (RSM). A two-level factorial design was applied to determine the effect of two independent variables (extraction time: X1 and % methanol: X2) on three response variables (total phenolic content: Y1, total flavonoid/anthocyanin content: Y2 and Trolox equivalent antioxidant capacity: Y3). The optimum conditions for extraction time and percent methanol were 36 min or 1 min and 62.25% or 53% for the defatted dabai pulp or peel, respectively. The RSM optimized extraction was compared with sonication-assisted extraction. Optimization results showed that defatted dabai parts had high total phenolic content and antioxidant capacity. Sonication-assisted extraction utilized the optimized extraction conditions had further increased the total phenolic content and antioxidant capacity of defatted dabai peel, but not in the pulp. Therefore, optimization of different extraction methods for the defatted fruit parts is recommended for future studies.
    Matched MeSH terms: Antioxidants
  19. Fulltext Exhaustive extraction of compounds from pomegranate peel and flesh using solvents of varying polarity
    Idris Aliyu Massaud, Atif Amin Baig, Mohd Adzim Khalili Rohin
    Asian Journal of Medicine and Biomedicine, 2018;1(1):10-13.
    MyJurnal
    Pomegranate fruit is the most studied part of punica granatum shrub. The fruit contains enormous
    amount of polyphenol compounds in the peel and arils (flesh) which are responsible for its antioxidant
    activity. The polyphenols present are of varying degree of lipophilicity and thus would require solvents
    of varying polarity to extract them. In this study, the effects of solvent type and homogenisation on
    extraction yield were considered. The fruit was first separated into peel and flesh and subsequently, one
    half of each of the peel and flesh were separately homogenised. Ethanol, ethylacetate and hexane were
    used to extract the polyphenol content of each of the four samples; non-homogenised peel (NP), nonhomogenised flesh (NF), homogenised peel (HP) and homogenised flesh (HF) in decreasing order of
    polarity using maceration method. The extraction was carried out successively using the residue
    recovered from previous extraction. Ethanol was used for a second time to complete the extraction
    process. The total extractive yield from the four samples were 27.19, 26.04, 25.03 and 15.61 for HP,
    NP, HF and NF respectively. The experiment has demonstrated that maceration process can be used to
    extract compounds from pomegranate to give a yield similar to more sophisticated method and ethanol
    is a suitable solvent for extracting hydrophilic compounds from the fruit.
    Matched MeSH terms: Antioxidants
  20. Fulltext Prevention of Cognitive Decline in Alzheimer's Disease by Novel Antioxidative Supplements
    Tadokoro K, Ohta Y, Inufusa H, Loon AFN, Abe K
    Int J Mol Sci, 2020 Mar 13;21(6).
    PMID: 32183152 DOI: 10.3390/ijms21061974
    Oxidative stress plays a crucial role in Alzheimer's disease (AD) from its prodromal stage of mild cognitive impairment. There is an interplay between oxidative stress and the amyloid β (Aβ) cascade via various mechanisms including mitochondrial dysfunction, lipid peroxidation, protein oxidation, glycoxidation, deoxyribonucleotide acid damage, altered antioxidant defense, impaired amyloid clearance, inflammation and chronic cerebral hypoperfusion. Based on findings that indicate that oxidative stress plays a major role in AD, oxidative stress has been considered as a therapeutic target of AD. In spite of favorable preclinical study outcomes, previous antioxidative components, including a single antioxidative supplement such as vitamin C, vitamin E or their mixtures, did not clearly show any therapeutic effect on cognitive decline in AD. However, novel antioxidative supplements can be beneficial for AD patients. In this review, we summarize the interplay between oxidative stress and the Aβ cascade, and introduce novel antioxidative supplements expected to prevent cognitive decline in AD.
    Matched MeSH terms: Antioxidants/administration & dosage; Antioxidants/pharmacology; Antioxidants/therapeutic use*
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