Displaying publications 1 - 20 of 52 in total

Abstract:
Sort:
  1. Influence of growth stage and season on the antioxidant constituents of Cosmos caudatus
    Mediani A, Abas F, Ping TC, Khatib A, Lajis NH
    Plant Foods Hum Nutr, 2012 Dec;67(4):344-50.
    PMID: 23054393 DOI: 10.1007/s11130-012-0317-x
    The impact of tropical seasons (dry and wet) and growth stages (8, 10 and 12 weeks) of Cosmos caudatus on the antioxidant activity (AA), total phenolic content (TPC) as well as the level of bioactive compounds were evaluated using high performance liquid chromatography (HPLC). The plant morphology (plant height) also showed variation between the two seasons. Samples planted from June to August (during the dry season) exhibited a remarkably higher bioactivity and height than those planted from October to December (during the wet season). The samples that were harvested at eight weeks of age during the dry season showed the highest bioactivity with values of 26.04 g GAE/100 g and 22.1 μg/ml for TPC and IC₅₀, respectively. Identification of phytochemical constituents in the C. caudatus extract was carried out by liquid chromatography coupled with diode array detection and electrospray tandem mass (LC-DAD-ESIMS/MS) technique and the confirmation of constituents was achieved by comparison with literature data and/or co-chromatography with authentic standards. Six compounds were indentified including quercetin 3-O-rhamnoside, quercetin 3-O-glucoside, rutin, quercetin 3-O-arabinofuranoside, quercetin 3-O-galactoside and chlorogenic acid. Their concentrations showed significant variance among the 8, 10 and 12-week-old herbs during both seasons.
  2. Fulltext Cosmos caudatus as a potential source of polyphenolic compounds: optimisation of oven drying conditions and characterisation of its functional properties
    Mediani A, Abas F, Khatib A, Tan CP
    Molecules, 2013 Aug 29;18(9):10452-64.
    PMID: 23994970 DOI: 10.3390/molecules180910452
    The aim of the study was to analyze the influence of oven thermal processing of Cosmos caudatus on the total polyphenolic content (TPC) and antioxidant capacity (DPPH) of two different solvent extracts (80% methanol, and 80% ethanol). Sonication was used to extract bioactive compounds from this herb. The results showed that the optimised conditions for the oven drying method for 80% methanol and 80% ethanol were 44.5 °C for 4 h with an IC₅₀ of 0.045 mg/mL and 43.12 °C for 4.05 h with an IC₅₀ of 0.055 mg/mL, respectively. The predicted values for TPC under the optimised conditions for 80% methanol and 80% ethanol were 16.5 and 15.8 mg GAE/100 g DW, respectively. The results obtained from this study demonstrate that Cosmos caudatus can be used as a potential source of antioxidants for food and medicinal applications.
  3. Fulltext Antioxidant, antityrosinase, anticholinesterase, and nitric oxide inhibition activities of three malaysian macaranga species
    Mazlan NA, Mediani A, Abas F, Ahmad S, Shaari K, Khamis S, et al.
    ScientificWorldJournal, 2013;2013:312741.
    PMID: 24319356 DOI: 10.1155/2013/312741
    The methanol extracts of three Macaranga species (M. denticulata, M. pruinosa, and M. gigantea) were screened to evaluate their total phenolic contents and activities as cholinesterase inhibitors, nitric oxide (NO) production inhibitors, tyrosinase inhibitors, and antioxidants. The bark of M. denticulata showed the highest total phenolic content (2682 mg gallic acid equivalent (GAE)/100 g) and free radical scavenging activity (IC50 = 0.063 mg/mL). All of the samples inhibited linoleic acid peroxidation by greater than 80%, with the leaves of M. gigantea exhibiting the highest inhibition of 92.21%. Most of the samples exhibited significant antioxidant potential. The bark of M. denticulata and the leaves of both M. pruinosa and M. gigantea exhibited greater than 50% tyrosinase inhibition, with the bark of M. denticulata having the highest percentage of inhibition (68.7%). The bark and leaves of M. denticulata exhibited greater than 50% inhibition (73.82% and 54.50%, resp.) of the acetylcholinesterase enzyme (AChE), while none of the samples showed any significant inhibition of butyrylcholinesterase (BChE). Only the bark of M. denticulata and M. gigantea displayed greater than 50% inhibition of nitric oxide production in cells (81.79% and 56.51%, resp.). These bioactivities indicate that some Macaranga spp. have therapeutic potential in medicinal research.
  4. Fulltext Effects of Different Drying Methods and Storage Time on Free Radical Scavenging Activity and Total Phenolic Content of Cosmos Caudatus
    Mediani A, Abas F, Tan CP, Khatib A
    Antioxidants (Basel), 2014 May 07;3(2):358-70.
    PMID: 26784876 DOI: 10.3390/antiox3020358
    The present study was conducted to determine the effect of air (AD), oven (OD) and freeze drying (FD) on the free radical scavenging activity and total phenolic content (TPC) of Cosmos caudatus and the effect of storage time by the comparison with a fresh sample (FS). Among the three drying methods that were used, AD resulted in the highest free radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) (IC50 = 0.0223 mg/mL) and total phenolic content (27.4 g GAE/100 g), whereas OD produced the lowest scavenging activity and TPC value. After three months of storage, the dried samples showed a high and consistent free radical scavenging activity when compared to stored fresh material. The drying methods could preserve the quality of C. caudatus during storage and the stability of its bioactive components can be maintained.
  5. GC-MS-based metabolite profiling of Cosmos caudatus leaves possessing alpha-glucosidase inhibitory activity
    Javadi N, Abas F, Abd Hamid A, Simoh S, Shaari K, Ismail IS, et al.
    J Food Sci, 2014 Jun;79(6):C1130-6.
    PMID: 24888400 DOI: 10.1111/1750-3841.12491
    Cosmos caudatus, which is known as "Ulam Raja," is an herbal plant used in Malaysia to enhance vitality. This study focused on the evaluation of the α-glucosidase inhibitory activity of different ethanolic extracts of C. caudatus. Six series of samples extracted with water, 20%, 40%, 60%, 80%, and 100% ethanol (EtOH) were employed. Gas chromatography-mass spectrometry (GC-MS) and orthogonal partial least-squares (OPLS) analysis was used to correlate bioactivity of different extracts to different metabolite profiles of C. caudatus. The obtained OPLS scores indicated a distinct and remarkable separation into 6 clusters, which were indicative of the 6 different ethanol concentrations. GC-MS can be integrated with multivariate data analysis to identify compounds that inhibit α-glucosidase activity. In addition, catechin, α-linolenic acid, α-D-glucopyranoside, and vitamin E compounds were identified and indicate the potential α-glucosidase inhibitory activity of this herb.
  6. Fulltext Antioxidant and α-glucosidase inhibitory activities of the leaf and stem of selected traditional medicinal plants
    Lee, S.Y., Mediani, A., Nur Ashikin, A.H., Abas, F., Azliana, A.B.S.
    International Food Research Journal, 2014;21(1):165-172.
    MyJurnal
    The study was aimed to determine the antioxidant and α-glucosidase inhibition activities of
    the stem and leaf of five different traditional medicinal plants. The studied plants exhibited
    varied antioxidant and α-glucosidase inhibition activities. The antioxidant activities of the
    plants were determined through their free radical scavenging capabilities using DPPH assay.
    The most potent antioxidant activity was demonstrated by Neptunia oleracea with an IC50 of
    35.45 and 29.72 μg/mL for leaf and stem, respectively. For α-glucosidase inhibition activity,
    Neptunia oleracea exhibited potential α-glucosidase inhibition activity with IC50 value of
    19.09 and 19.74 μg/mL for leaf and stem, respectively. The highest total phenolic content
    (TPC) was also marked in Neptunia oleracea leaf and stem with value of 40.88 and 21.21 mg
    GAE/g dry weight, respectively. The results also showed that Strobilanthes crispus collected
    from two different locations possessed different levels of phenolic content, antioxidant and
    α-glucosidase inhibition activities. The study revealed that phenolic compounds could be the
    main contributors to the antioxidant and α-glucosidase inhibition activities with R values of 78.9
    and 67.4%, respectively. In addition, antioxidant and α-glucosidase were positively correlated
    (R = 81.9%). Neptunia oleracea could be suggested as a potential natural source of antioxidant
    and antidiabetic compounds that can be used for the prevention or treatment of diabetes.
  7. Relationship Between Metabolites Composition and Biological Activities of Phyllanthus niruri Extracts Prepared by Different Drying Methods and Solvents Extraction
    Mediani A, Abas F, Khatib A, Tan CP, Ismail IS, Shaari K, et al.
    Plant Foods Hum Nutr, 2015 Jun;70(2):184-92.
    PMID: 25800644 DOI: 10.1007/s11130-015-0478-5
    The study investigated the changes in the metabolite, antioxidant and α-glucosidase inhibitory activities of Phyllanthus niruri after three drying treatments: air, freeze and oven dryings. Water extracts and extracts obtained using different solvent ratios of ethanol and methanol (50, 70, 80 and 100%) were compared. The relationships among the antioxidant, α-glucosidase inhibitory activity and metabolite levels of the extracts were evaluated using partial least-square analysis (PLS). The solvent selectivity was assessed based on the phytochemical constituents present in the extract and their concentrations quantitatively analyzed using high performance liquid chromatography. The freeze-dried P. niruri samples that were extracted with the mixture of ethanol or methanol with low ratio of water showed higher biological activity values compared with the other extracts. The PLS results for the ethanolic with different ratio and water extracts demonstrated that phenolic acids (chlorogenic acid and ellagic acid) and flavonoids were highly linked to strong α-glucosidase inhibitory and antioxidant activities.
  8. Effect of storage time on metabolite profile and alpha-glucosidase inhibitory activity of Cosmos caudatus leaves - GCMS based metabolomics approach
    Javadi N, Abas F, Mediani A, Abd Hamid A, Khatib A, Simoh S, et al.
    J Food Drug Anal, 2015 Sep;23(3):433-441.
    PMID: 28911700 DOI: 10.1016/j.jfda.2015.01.005
    Cosmos caudatus, which is a commonly consumed vegetable in Malaysia, is locally known as "Ulam Raja". It is a local Malaysian herb traditionally used as a food and medicinal herb to treat several maladies. Its bioactive or nutritional constituents consist of a wide range of metabolites, including glucosinolates, phenolics, amino acids, organic acids, and sugars. However, many of these metabolites are not stable and easily degraded or modified during storage. In order to investigate the metabolomics changes occurring during post-harvest storage, C. caudatus samples were subjected to seven different storage times (0 hours, 2 hours, 4 hours, 6 hours, 8 hours, 10 hours, and 12 hours) at room temperature. As the model experiment, the metabolites identified by gas chromatography-mass spectrometry (GC-MS) were correlated with α-glucosidase inhibitory activity analyzed with multivariate data analysis (MVDA) to find out the variation among samples and metabolites contributing to the activity. Orthogonal partial least squares (OPLS) analysis was applied to investigate the metabolomics changes. A profound chemical alteration, both in primary and secondary metabolites, was observed. The α-tocopherol, catechin, cyclohexen-1-carboxylic acid, benzoic acid, myo-inositol, stigmasterol, and lycopene compounds were found to be the discriminating metabolites at early storage; however, sugars such as sucrose, α-d-galactopyranose, and turanose were detected, which was attributed to the discriminating metabolites for late storage. The result shows that the MVDA method is a promising technique to identify biomarker compounds relative to storage at different times.
  9. Fulltext Physicochemical and functional properties of yeast fermented brown rice flour
    Ilowefah M, Bakar J, Ghazali HM, Mediani A, Muhammad K
    J Food Sci Technol, 2015 Sep;52(9):5534-45.
    PMID: 26344967 DOI: 10.1007/s13197-014-1661-7
    In the current study, effects of fermentation on physicochemical and functional properties of brown rice flour (BRF) were investigated. Fermentation conditions were optimized using response surface methodology to achieve moderate acidity (pH 5-6), specifically pH 5.5 of brown rice batter with time, temperature and yeast concentration as the independent variables. The results indicated that brown rice batter was well fermented to maintain pH 5.5 at optimum conditions of 32 °C for 6.26 h using 1 % yeast concentration. Fermentation at moderate acidity significantly increased the levels of protein, total ash, insoluble fiber, soluble fibre, minerals, phenolics, antioxidants, resistant starch, riboflavin, pyridoxine, nicotinic acid, γ-tocotrienol, and δ-tocotrienol. However, it reduced the contents of γ-oryzanol, γ-tocopherol, α-tocopherol, phytic acid, amylose and total starch. Foaming capacity, foaming stability, oil holding capacity, gelatinization temperatures, enthalpy and whiteness of BRF were increased after fermentation. In contrast, its swelling power, water solubility index, hot paste viscosity, breakdown, and setback significantly decreased. Microstructure of BRF was also influenced, where its starch granules released from its enclosed structure after fermentation. This investigation shows evidence that yeast fermentation modified the functionality of BRF and can be used as a functional food ingredient.
  10. Metabolic and biochemical changes in streptozotocin induced obese-diabetic rats treated with Phyllanthus niruri extract
    Mediani A, Abas F, Maulidiani M, Khatib A, Tan CP, Ismail IS, et al.
    J Pharm Biomed Anal, 2016 Sep 05;128:302-312.
    PMID: 27318080 DOI: 10.1016/j.jpba.2016.06.003
    Herbal medicine has been proven to be an effective therapy offering a variety of benefits, such as moderate reduction in hypoglycemia, in the treatment and prevention of obesity and diabetes. Phyllanthus niruri has been used as a treatment for diabetes mellitus. Herein, the induction of type 2 diabetes in Sprague-Dawley rats was achieved by a low dose of streptozotocin (STZ) (25mg/kgbw). Here, we evaluated the in vivo antidiabetic properties of two concentrations (250 and 500mg/kg bw) of P. niruri via metabolomics approach. The administration of 500mg/kgbw of P. niruri extract caused the metabolic disorders of obese diabetic rats to be improved towards the normal state. The extract also clearly decreased the serum glucose level and improved the lipid profile in obese diabetic rats. The results of this study may contribute towards better understanding the molecular mechanism of this medicinal plant in managing diabetes mellitus.
  11. Discrimination and Nitric Oxide Inhibitory Activity Correlation of Ajwa Dates from Different Grades and Origin
    Abdul-Hamid NA, Mediani A, Maulidiani M, Abas F, Ismail IS, Shaari K, et al.
    Molecules, 2016 Oct 28;21(11).
    PMID: 27801841
    This study was aimed at examining the variations in the metabolite constituents of the different Ajwa grades and farm origins. It is also targeted at establishing the correlations between the metabolite contents and the grades and further to the nitric oxide (NO) inhibitory activity. Identification of the metabolites was generated using ¹H-NMR spectroscopy metabolomics analyses utilizing multivariate methods. The NO inhibitory activity was determined using a Griess assay. Multivariate data analysis, for both supervised and unsupervised approaches, showed clusters among different grades of Ajwa dates obtained from different farms. The compounds that contribute towards the observed separation between Ajwa samples were suggested to be phenolic compounds, ascorbic acid and phenylalanine. Ajwa dates were shown to have different metabolite compositions and exhibited a wide range of NO inhibitory activity. It is also revealed that Ajwa Grade 1 from the al-Aliah farm exhibited more than 90% NO inhibitory activity compared to the other grades and origins. Phenolic compounds were among the compounds that played a role towards the greater capacity of NO inhibitory activity shown by Ajwa Grade 1 from the al-Aliah farm.
  12. Characterization of metabolites in different kiwifruit varieties by NMR and fluorescence spectroscopy
    Abdul Hamid NA, Mediani A, Maulidiani M, Abas F, Park YS, Leontowicz H, et al.
    J Pharm Biomed Anal, 2017 May 10;138:80-91.
    PMID: 28189049 DOI: 10.1016/j.jpba.2017.01.046
    It is known from our previous studies that kiwifruits, which are used in common human diet, have preventive properties of coronary artery disease. This study describes a combination of (1)H NMR spectroscopy, multivariate data analyses and fluorescence measurements in differentiating of some kiwifruit varieties, their quenching and antioxidant properties. A total of 41 metabolites were identified by comparing with literature data Chenomx database and 2D NMR. The binding properties of the extracted polyphenols against HSA showed higher reactivity of studied two cultivars in comparison with the common Hayward. The results showed that the fluorescence of HSA was quenched by Bidan as much as twice than by other fruits. The correlation between the binding properties of polyphenols in the investigated fruits, their relative quantification and suggested metabolic pathway was established. These results can provide possible application of fruit extracts in pharmaceutical industry.
  13. Metabolite Variation in Lean and Obese Streptozotocin (STZ)-Induced Diabetic Rats via (1)H NMR-Based Metabolomics Approach
    Abu Bakar Sajak A, Mediani A, Maulidiani, Ismail A, Abas F
    Appl Biochem Biotechnol, 2017 Jun;182(2):653-668.
    PMID: 27995574 DOI: 10.1007/s12010-016-2352-9
    Diabetes mellitus (DM) is considered as a complex metabolic disease because it affects the metabolism of glucose and other metabolites. Although many diabetes studies have been conducted in animal models throughout the years, the pathogenesis of this disease, especially between lean diabetes (ND + STZ) and obese diabetes (OB + STZ), is still not fully understood. In this study, the urine from ND + STZ, OB + STZ, lean/control (ND), and OB + STZ rats were collected and compared by using (1)H NMR metabolomics. The results from multivariate data analysis (MVDA) showed that the diabetic groups (ND + STZ and OB + STZ) have similarities and dissimilarities for a certain level of metabolites. Differences between ND + STZ and OB + STZ were particularly noticeable in the synthesis of ketone bodies, branched-chain amino acid (BCAA), and sensitivity towards the oral T2DM diabetes drug metformin. This finding suggests that the ND + STZ group was more similar to the T1DM model and OB + STZ to the T2DM model. In addition, we also managed to identify several pathways and metabolism aspects shared by obese (OB) and OB + STZ. The results from this study are useful in developing drug target-based research as they can increase understanding regarding the cause and effect of DM.
  14. Effect of Ipomoea aquatica ethanolic extract in streptozotocin (STZ) induced diabetic rats via1H NMR-based metabolomics approach
    Abu Bakar Sajak A, Mediani A, Maulidiani, Mohd Dom NS, Machap C, Hamid M, et al.
    Phytomedicine, 2017 Dec 01;36:201-209.
    PMID: 29157816 DOI: 10.1016/j.phymed.2017.10.011
    BACKGROUND: Ipomoea aquatica (locally known as "kangkung") has previously been reported to have hypoglycemic activities on glucose level in diabetes patients. However, the effect of I. aquatica ethanolic extract on the metabolites in the body has remained unknown.

    PURPOSE: This study provides new insights on the changes of endogenous metabolites caused by I. aquatica ethanolic extract and improves the understanding on the therapeutic efficacy and mechanism of I. aquatica ethanolic extract.

    METHODS: By using a combination of 1H nuclear magnetic resonance (NMR) with multivariate analysis (MVDA), the changes of metabolites due to I. aquatica ethanolic extract administration in obese diabetic-induced Sprague Dawley rats (OB+STZ+IA) were identified.

    RESULTS: The results suggested 19 potential biomarkers with variable importance projections (VIP) above 0.5, which include creatine/creatinine, glucose, creatinine, citrate, carnitine, 2-oxoglutarate, succinate, hippurate, leucine, 1-methylnicotinamice (MNA), taurine, 3-hydroxybutyrate (3-HB), tryptophan, lysine, trigonelline, allantoin, formiate, acetoacetate (AcAc) and dimethylamine. From the changes in the metabolites, the affected pathways and aspects of metabolism were identified.

    CONCLUSION: I. aquatica ethanolic extract increases metabolite levels such as creatinine/creatine, carnitine, MNA, trigonelline, leucine, lysine, 3-HB and decreases metabolite levels, including glucose and tricarboxylic acid (TCA) intermediates. This implies capabilities of I. aquatica ethanolic extract promoting glycolysis, gut microbiota and nicotinate/nicotinamide metabolism, improving the glomerular filtration rate (GFR) and reducing the β-oxidation rate. However, the administration of I. aquatica ethanolic extract has several drawbacks, such as unimproved changes in amino acid metabolism, especially in reducing branched chain amino acid (BCAA) synthesis pathways and lipid metabolism.

  15. Fulltext Stability Study of Algerian Nigella sativa Seeds Stored under Different Conditions
    Ahamad Bustamam MS, Hadithon KA, Mediani A, Abas F, Rukayadi Y, Lajis N, et al.
    J Anal Methods Chem, 2017;2017:7891434.
    PMID: 28255502 DOI: 10.1155/2017/7891434
    In a study to determine the stability of the main volatile constituents of Nigella sativa seeds stored under several conditions, eight storage conditions were established, based on the ecological abiotic effects of air, heat, and light. Six replicates each were prepared and analyzed with Headspace-Gas Chromatography-Mass Spectrometry (HS-GC-MS) for three time points at the initial (1st day (0)), 14th (1), and 28th (2) day of storage. A targeted multivariate analysis of Principal Component Analysis revealed that the stability of the main volatile constituents of the whole seeds was better than that of the ground seeds. Exposed seeds, whole or ground, were observed to experience higher decrement of the volatile composition. These ecofactors of air, heat, and light are suggested to be directly responsible for the loss of volatiles in N. sativa seeds, particularly of the ground seeds.
  16. Fulltext Effect of different drying methods and solvent ratios on biological activities of Phyllanthus acidus extracts
    Siti Zulaikha, A.G., Mediani, A., Khoo, L.W., Lee, S.Y., Leong, S.W., Abas, F.
    International Food Research Journal, 2017;24(1):114-120.
    MyJurnal
    The main purpose of this study was to evaluate the antioxidant and α-glucosidase inhibitory
    activities of Phyllanthus acidus. The P. acidus fruits were dried using three different methods,
    namely oven (OD), air (AD) and freeze (FD) dryings and extracted with ethanol at different
    ratios (50 and 100%). The proximate analysis and total phenolic content (TPC) as well as
    free radical scavenging and α-glucosidase inhibitory activities were determined. The proximate
    analysis of P. acidus fruit indicated that all the dried samples contained potential nutrient
    contents. The highest TPC value, α-glucosidase inhibitory and antioxidant activities were
    observed for 50% ethanolic extract from OD method with TPC value of 28.39 mg GAE/g dried
    extract, IC50 value of 12.394 μg/mL and 64.17% inhibition, respectively. The study revealed
    that phenolic compounds could be the main contributors to the antioxidant and α-glucosidase
    inhibitory activities based on the Pearson correlation coefficients with R values of 95.0 and
    73.8%, respectively. The study could provide scientific evidence for some folk uses in the
    treatment of diseases related to the production of reactive oxygen species and oxidative stress.
  17. Fulltext Comparison of ASE with in-cell cleanup and the QuEChERS sample preparation methods for the analysis of pesticide residues in tea
    Abdul Kadir, H., Abas, F., Mediani, A., Ismail, I.S., Lajis, N.H.
    International Food Research Journal, 2017;24(1):26-267.
    MyJurnal
    The aim of the present work was to compare and choose the best method to extract incurred
    pesticide residues from green tea. Accelerated solvent extraction (ASE) with in-cell cleanup
    and the quick, easy, cheap, effective rugged and safe (QuEChERS) methods were tested on
    green tea samples with incurred beta-endosulfan pesticide. The extracts were analyzed by
    GC-MS/MS and the recovery and the precision of both methods were compared. The average
    recovery using ASE with the in-cell cleanup method was in the range of 89 to 92% which is
    better than that obtained using a QuEChERS method. Both the ASE with in-cell cleanup and
    the QuEChERS methods provided good precision with RSDs in the range of 12 to 15% and
    17 to 18%, respectively. This finding indicates that the ASE method with the in-cell cleanup is
    more suitable for the accurate determination of pesticides incurred in tea.
  18. Comparison of partial least squares and random forests for evaluating relationship between phenolics and bioactivities of Neptunia oleracea
    Lee SY, Mediani A, Maulidiani M, Khatib A, Ismail IS, Zawawi N, et al.
    J Sci Food Agric, 2018 Jan;98(1):240-252.
    PMID: 28580581 DOI: 10.1002/jsfa.8462
    BACKGROUND: Neptunia oleracea is a plant consumed as a vegetable and which has been used as a folk remedy for several diseases. Herein, two regression models (partial least squares, PLS; and random forest, RF) in a metabolomics approach were compared and applied to the evaluation of the relationship between phenolics and bioactivities of N. oleracea. In addition, the effects of different extraction conditions on the phenolic constituents were assessed by pattern recognition analysis.

    RESULTS: Comparison of the PLS and RF showed that RF exhibited poorer generalization and hence poorer predictive performance. Both the regression coefficient of PLS and the variable importance of RF revealed that quercetin and kaempferol derivatives, caffeic acid and vitexin-2-O-rhamnoside were significant towards the tested bioactivities. Furthermore, principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) results showed that sonication and absolute ethanol are the preferable extraction method and ethanol ratio, respectively, to produce N. oleracea extracts with high phenolic levels and therefore high DPPH scavenging and α-glucosidase inhibitory activities.

    CONCLUSION: Both PLS and RF are useful regression models in metabolomics studies. This work provides insight into the performance of different multivariate data analysis tools and the effects of different extraction conditions on the extraction of desired phenolics from plants. © 2017 Society of Chemical Industry.

  19. Fulltext Metabolite profiling, antioxidant, and α-glucosidase inhibitory activities of germinated rice: nuclear-magnetic-resonance-based metabolomics study
    Pramai P, Abdul Hamid NA, Mediani A, Maulidiani M, Abas F, Jiamyangyuen S
    J Food Drug Anal, 2018 01;26(1):47-57.
    PMID: 29389588 DOI: 10.1016/j.jfda.2016.11.023
    In an attempt to profile the metabolites of three different varieties of germinated rice, specifically black (GBR), red, and white rice, a 1H-nuclear-magnetic-resonance-based metabolomics approach was conducted. Multivariate data analysis was applied to discriminate between the three different varieties using a partial least squares discriminant analysis (PLS-DA) model. The PLS model was used to evaluate the relationship between chemicals and biological activities of germinated rice. The PLS-DA score plot exhibited a noticeable separation between the three rice varieties into three clusters by PC1 and PC2. The PLS model indicated that α-linolenic acid, γ-oryzanol, α-tocopherol, γ-aminobutyric acid, 3-hydroxybutyric acid, fumaric acid, fatty acids, threonine, tryptophan, and vanillic acid were significantly correlated with the higher bioactivities demonstrated by GBR that was extracted in 100% ethanol. Subsequently, the proposed biosynthetic pathway analysis revealed that the increased quantities of secondary metabolites found in GBR may contribute to its nutritional value and health benefits.
  20. Fulltext Metabolite characterization of different palm date varieties and the correlation with their NO inhibitory activity, texture and sweetness
    Abdul-Hamid NA, Mediani A, Maulidiani M, Shadid K, Ismail IS, Abas F, et al.
    J Food Sci Technol, 2018 Apr;55(4):1541-1551.
    PMID: 29606769 DOI: 10.1007/s13197-018-3073-6
    The aim of this study was to examine the variation in metabolite constituents of five commercial varieties of date fruits; Ajwa, Safawi and Ambar which originated from Madinah, the Iranian Bam and Tunisian Deglet Noor. The differences of metabolome were investigated using proton nuclear magnetic resonance (1H NMR) spectroscopy combined with multivariate data analysis (MVDA). Principal Component Analysis (PCA) revealed clear separation between the date varieties. The Tunisian Deglet Noor demonstrated distinct cluster from the rest of the palm date samples based on the metabolite composition as shown by the pattern observed in Hierarchical Clustering Analysis (HCA) and PCA. Deglet Noor exhibited a significant higher level of sucrose (δ 5.40) and fructose (δ 4.16) in comparison with the other four varieties which can be associated with the distinctive sweet taste of this variety. Dates originated from Madinah and Tunisia exhibited a contrast manner in the amount of xylose and moisture content. These two aspects may contribute towards the soft texture of Tunisian dates. All Madinah dates were found to contain phenolic compounds which were well established as great antioxidant and anti-inflammatory agent. Ajwa dates exerted greater effect in inhibiting the generation of nitric oxide (NO) from the stimulated RAW264.7 cells at 95.37% inhibition. Succinic acid was suggested to have the most significant correlation with the trend of NO inhibitory shown by the selected date palm varieties.
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links