Displaying publications 41 - 60 of 127 in total

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  1. Muhammad Helmi Nadri, Kian, Kai Cheng, Pei, Ying Ong, Hong, Yeng L., Nor Zalina Othman, Nur Fashya Musa, et al.
    MyJurnal
    Ipomea aquatica, locally known as water spinach, is one of the most common vegetable consumed by
    Malaysian. Based on previous studies, crude extract and phenolic compounds of I. aquatica exhibited
    several biological activities including antioxidant, anti-microbial and anti-proliferative. The presence
    of phenolic compounds in I. aquatica may contributed to their ability to inhibit enzymes, chelate
    metals and scavenge free radicals. Currently, no study reported on anti-inflammatory activity of I.
    aquatica with respect to lipoxygenase, hyaluronidase and xanthine oxidase enzymes. The present
    study aims to enhance current knowledge on biological properties of I. aquatica crude extract
    particularly on anti-inflammatory activity. Three enzymes that involve in inflammatory pathway were
    selected in this study including lipoxygenase, hyaluronidase and xanthine oxidase. I. aquatica was
    extracted in methanol and tested for lipoxygenase, hyaluronidase and xanthine oxidase at different
    concentrations using direct enzyme inhibition assay. Lipoxygenase, hyaluronidase and xanthine
    oxidase inhibitory activities of the methanol crude extract increased with increasing
    concentration. Highest inhibition activity against lipoxygenase, hyaluronidase and xanthine oxidase
    were observed at a concentration of 1000 µg/ml with inhibition of 87.18%, 95.36% and 78.38%,
    respectively. Our finding in this study indicates potential anti-inflammatory activity of I. aquatica
    crude extract through inhibition of lipoxygenase, hyaluronidase and xanthine oxidase.
    Matched MeSH terms: Free Radicals
  2. Ashraf I, Zubair M, Rizwan K, Rasool N, Jamil M, Khan SA, et al.
    Chem Cent J, 2018 Dec 17;12(1):135.
    PMID: 30556121 DOI: 10.1186/s13065-018-0495-1
    This research work was executed to determine chemical composition, anti-oxidant and anti-microbial potential of the essential oils extracted from the leaves and stem of Daphne mucronata Royle. From leaves and stem oils fifty-one different constituents were identified through GC/MS examination. The antioxidant potential evaluated through DPPH free radical scavenging activity and %-inhibition of peroxidation in linoleic acid system. The stem's essential oil showed the good antioxidant activity as compared to leaves essential oil. Results of Antimicrobial activity revealed that both stem and leaves oils showed strong activity against Candida albicans with large inhibition zone (22.2 ± 0.01, 18.9 ± 0.20 mm) and lowest MIC values (0.98 ± 0.005, 2.44 ± 0.002 mg/mL) respectively. Leaves essential was also active against Escherichia coli with inhibition zone of 8.88 ± 0.01 mm and MIC values of 11.2 ± 0.40 mg/mL. These results suggested that the plant's essential oils would be a potential cradle for the natural product based antimicrobial as well as antioxidant agents.
    Matched MeSH terms: Free Radicals
  3. Yap PG, Gan CY
    Foods, 2021 Mar 22;10(3).
    PMID: 33810046 DOI: 10.3390/foods10030675
    Nature-derived tyrosinase inhibitors are of great industrial interest. Three monophenolase inhibitor peptides (MIPs) and three diphenolase inhibitor peptides (DIPs) from a previous study were investigated for their in vitro tyrosinase inhibitory effects, mode of inhibition, copper-chelating activity, sun protection factor (SPF) and antioxidant activities. DIP1 was found to be the most potent tyrosinase inhibitor (IC50 = 3.04 ± 0.39 mM), which could be due to the binding interactions between its aromatic amino acid residues (Y2 and D7) with tyrosinase hotspots (H85, V248, H258, H263, F264, R268, V283 and E322) and its ability to chelate copper ion within the substrate-binding pocket. The conjugated planar rings of tyrosine and tryptophan may interact with histidine within the active site to provide stability upon enzyme-peptide binding. This postulation was later confirmed as the Lineweaver-Burk analysis had identified DIP1 as a competitive inhibitor and DIP1 also showed 36.27 ± 1.17% of copper chelating activity. In addition, DIP1 provided the highest SPF value (11.9 ± 0.04) as well as ferric reducing antioxidant power (FRAP) (5.09 ± 0.13 mM FeSO4), 2,2'-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) (11.34 ± 0.90%) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) (29.14 ± 1.36%) free radical scavenging activities compared to other peptides. These results demonstrated that DIP1 could be a multifunctional anti-tyrosinase agent with pharmaceutical and cosmeceutical applications.
    Matched MeSH terms: Free Radicals
  4. Rahman ML, Puah PY, Sarjadi MS, Arshad SE, Musta B, Sarkar SM
    J Nanosci Nanotechnol, 2019 09 01;19(9):5796-5802.
    PMID: 30961741 DOI: 10.1166/jnn.2019.16538
    Ion-imprinting polymers (IIPs) materials draw the great recognition because of the powerful selectivity to the desired metal ions. Therefore, the ion-imprinting polymer (Ce-IIP) was prepared by using cerium metal with amidoxime ligand as the complexing agent, in addition ethylene glycol dimethacrylate (EGDMA) and 2,2-azobisisobutyronitrile (AIBN) are crosslinking agent and free radical initiator, respectively. Aqueous HCl was applied to leach the cerium ions from the imprinted polymer for the creation of cavities of template, which is utilized for further cerium ions adsorption with high selectivity. The Ce-IIP was characterized by using ICP-MS, FE-SEM and also solid state analysis by UV-vis NIR spectroscopy. FT-IR study confirmed the complexation of the Ce-IIP was successful. The optimum pH was found to be 6 and the highest adsorption capacity was estimated about 145 mg g-1. Thus, the prepared Ce-IIP gave very good selectivity to cerium ions in the presence of lanthanide ions and also Ce-IIP can be reused 10 times without a substantial loss in adsorption capacity.
    Matched MeSH terms: Free Radicals
  5. Ng JC, Tan CY, Ong BH, Matsuda A, Basirun WJ, Tan WK, et al.
    J Nanosci Nanotechnol, 2019 Nov 01;19(11):7236-7243.
    PMID: 31039881 DOI: 10.1166/jnn.2019.16717
    Small sized electrocatalysts, which can be obtained by rapid nucleation and high supersaturation are imperative for outstanding methanol oxidation reaction (MOR). Conventional microwave synthesis processes of electrocatalysts include ultrasonication, stirring, pH adjustment, and microwave irradiation of the precursor mixture. Ethylene glycol (EG), which serves as a reductant and solvent was added during the ultrasonication or stirring stage. However, this step and pH adjustment resulted in unintended multi-stage gradual nucleation. In this study, the microwave reduction approach was used to induce rapid nucleation and high supersaturation in order to fabricate small-sized reduced graphene oxide-supported palladium (Pd/rGO) electrocatalysts via the delayed addition of EG, elimination of the pH adjustment step, addition of sodium carbonate (Na₂CO₃), prior microwave irradiation of the EG mixed with Na₂CO₃, and addition of room temperature precursor mixture. Besides its role as a second reducing agent, the addition of Na₂CO₃ was primarily intended to generate an alkaline condition, which is essential for the high-performance of electrocatalysts. Moreover, the microwave irradiation of the EG and Na₂CO₃ mixture generated highly reactive free radicals that facilitate rapid nucleation. Meanwhile, the room temperature precursor mixture increased supersaturation. Results showed improved electrochemically active surface area (78.97 m² g-1, 23.79% larger), MOR (434.49 mA mg-1, 37.96% higher) and stability.
    Matched MeSH terms: Free Radicals
  6. Loy, S.L., Hamid Jan, J.M., Sirajudeen, K.N.S.
    Malays J Nutr, 2013;19(3):383-399.
    MyJurnal
    Critical time windows exert profound influences on foetal physiological and metabolic profiles, which predispose an individual to later diseases via a 'programming' effect. Obesity has been suggested to be 'programmed' during early life. Foetuses and infants who experience adverse growth are subjected to a higher risk of obesity. However, the key factors that link adverse foetal growth and obesity risk remain obscure. To date, there is considerable evidence showing that the overall balance between free radical damage and the anti.oxidative process being challenged occurs throughout gestation. With the view that pregnancy is a pro-inflammatory state confronted with enhanced oxidative stress, which possesses similar characteristics to obesity (a chronic inflammatory state with increased oxidative stress), oxidative stress is thus biologically plausibly be proposed as the underlying mechanism between this causal-disease relationship. Oxidative stress could act as a programming cue for the development of obesity by inducing complex functional and metabolic deregulations as well as inducing the alteration of the adipogenesis process. Thereby, oxidative stress promotes adipose tissue deposition from early life onwards. The enhancement of fat accumulation further exaggerates oxidative derangement and perpetuates the cycle of adiposity. This review focuses on the oxidative stress pathways in prenatal and early postnatal stages, from the aspects of various endogenous and exogenous oxidative insults. Because oxidative stress is a modifiable pathway, this modifiability suggests a potential therapeutic target to fight the obesity epidemic by understanding the causal factors of oxidant induction.
    Matched MeSH terms: Free Radicals
  7. Norlaili, A.H., Roselina, K., Muhammad, T.S.
    Malays J Nutr, 2014;20(3):403-415.
    MyJurnal
    Introduction: Cosmos caudatus (Ulam Raja) is rich in phytochemicals and can be utilised in diet diversification strategies to improve the health of individuals. lbis study was designed to incorporate dry and aqueous extracts of C. caudatus for the preparation of herbal noodles. Methods: For this purpose, different proportions of dry extract (2, 4 and 6% dry extract) and aqueous extract (5, 10 and 15% aqueous extract) of C. caudatus were used. The physicochemical properties of noodles evaluated were pH, cooking time, cooking loss, texture and colour. Total polyphenol contents (TPq and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay were carried out to assess the antioxidant potential. Lastly, sensory appraisal of functional noodles was carried out to assess consumer acceptance and marketability. Results: The results on physicochemical properties indicated that the pH value of noodles varied from 8.66 to 10.47. In terms of textural analysis and colour properties, firmness and greenness (a*) were higher in dry extract noodles. TPC varied between 115to149 mg gallic acid equivalents (GAE/lOOg) whilst the highest DPPH free radical inhibition was exhibited in herbal noodles prepared using 4% dry extract (92.8%). In contrast, in terms of sensory appraisal, herbal noodles prepared with aqueous extract were more acceptable than dry extract noodles. Conclusion: C. caudatus can be utilised to prepare herbal noodles thus enhancing the dietary intake of phytochemicals especially antioxidants. Such functional foods can improve the health of consumers and offer the potential of protection against various ailments.
    Matched MeSH terms: Free Radicals
  8. Jaafar NF, Ramli ME, Mohd Salleh R
    Trop Life Sci Res, 2020 Jul;31(2):1-17.
    PMID: 32922666 DOI: 10.21315/tlsr2020.31.2.1
    Clitoria ternatea is a herbaceous plant with many health benefits. Extraction is crucial to obtain its bioactive components which contribute to its antioxidant properties. Therefore, this study was conducted to find an optimum extraction condition of C. ternatea flower on total phenolic content (TPC) and antioxidant activity (2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging activity) as well as to determine its total flavonoid content (TFC) and anthocyanin content based on the optimum extraction condition generated by Response Surface Methodology (RSM)-Design Expert 7.1.5. TPC, TFC and total anthocyanin of C. ternatea were conducted by Folin Ciocalteu (FC), calorimetric assay and pH differential method, respectively. The ranges of selected independent variables were ethanol concentration (30°C-90% v/v), time (60-120 min) and temperature (30°C-70°C). The optimum extraction condition was obtained at 39.62% v/v ethanol concentration, 90 min and 44.24°C. However, these values were slightly adjusted according to the convenience of equipment to operate in which ethanol concentration was adjusted to 37% v/v, time remain at 90 min and temperature at 45°C. The predicted values of TPC and DPPH radical scavenging activity were 41.60 mg GAE/g dry samples and 68.12% inhibition and were experimentally verified to be 41.17 ± 0.5 mg GAE/g dry samples and 63.53 ± 0.95% inhibition of TPC and DPPH radical scavenging activity respectively. This result has showed RSM can optimise TPC and radical scavenging activity of C. ternatea. Upon the optimum condition, the TFC determined was 187.05 ± 3.18 mg quercetin/g dried sample which was higher than TPC and the total anthocyanin content was 28.60 ± 0.04 mg/L. Hence, the extractable phenolic, flavonoid and anthocyanin compounds indicated that C. ternatea is a good source of natural antioxidant.
    Matched MeSH terms: Free Radicals
  9. Marina, Z., Noriham, A.
    MyJurnal
    This study was undertaken to evaluate the potential of fruit waste materials as source of natural antioxidant. The fruit peels including mango, guava and papaya peel were used in this study. The total phenolic content (TPC) was determined by Folin-Ciocalteu assay while antioxidant activities were determined by using ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging, ferric thiocynate (FTC) and thiobarbituric acid (TBA) assays. These antioxidant activities were compared to synthetic antioxidants, BHA/BHT combination and ascorbic acid. The results demonstrated that TPC ranged from 3.23 to 15.84 g GAE/100 g extract. Mango peels extract exhibited highest TPC compared to guava peel and papaya peel extract. In the FRAP assay, mango peel extract at 200 ppm, guava peel extract at 400 ppm and papaya peel extract at 1200 ppm, exhibited reducing power comparable to the permissible amount of BHA/BHT at 200 ppm. At concentration of 250 μg/ml, the DPPH radical scavenging activity of extracts and standards decreased significantly in the order of mango peel extract > guava peel extract > BHA/BHT > ascorbic acid > papaya peel extract. For the FTC assay, the antioxidant activity of mango peel extract was significantly higher than ascorbic acid, guava peel and papaya peel extract but lower than BHA/BHT while in the TBA assay, percentage inhibition of BHA/BHT and ascorbic acid were found to be higher than fruit peel extracts. The quantitative analysis for flavonoids showed the presence of catechin, epicatechin and kaempferol in the peel extracts.
    Matched MeSH terms: Free Radicals
  10. Nur Syukriah, A.R., Liza, M.S., Harisun, Y., Fadzillah, A.A.M.
    MyJurnal
    Bioactive compounds from Quercus Infectoria (manjakani) were extracted with six different types of solvents: 100% methanol, ethanol, acetone, aqueous and 70% methanol and ethanol. High Performance liquid chromatography (HPLC) was used to identify and quantify the active compounds, namely gallic acid and tannic acid. Total phenolics content were determined by Folin-Ciocalteu while antioxidant and antibacterial activity were tested using DPPH free radicals scavenging and disc diffusion assay. The result revealed that aqueous extract contained the highest concentration of bioactive compounds compared to other types of solvents which are 51.14 mg/g sample and 1332.88 mg/g sample of gallic acid and tannic acid respectively.. The highest level of phenolic compound was found in 100% acetone extract (121 mg GAE/g). The results demonstrated that aqueous extract gives the highest antioxidant activity approximately 94.55% while acetone extract gives the largest inhibition zone for disc diffusion assay which is 19.00 mm respectively. The results revealed rich sources of gallic acid and tannic acid in Q. infectoria which might provide a novel source of these natural antioxidant and antibacterial activity.
    Matched MeSH terms: Free Radicals
  11. Philip, Y., Mohd Fadzelly, A. B.
    MyJurnal
    Honey is a sweet substance that can be obtain from flower nectar and secretes through transformations process by honey bees. The aim of this study was to compare the antioxidant and anti-cholinesterase activities of 4 wild honey (wild honey produced by different species of bees: Apis cerana, Apis andreniformis, Apis koschevnikovi and Apis nuluensis) collected from the secondary forest and 6 commercial (young and old Mangrove, young and old Upper mountain, Tropical, Potiukan) honey of Sabah, Malaysian Borneo. Antioxidant activities were determined using FRAP (Ferric Reducing Antioxidant Power), DPPH free radical scavenging and ABTS decolourization assays. Acetylcholinesterase inhibition effect was determined by enzyme inhibition method. The results of this study showed that wild honey produced by A.cerana collected from the Acacia tree extracted using 80% methanol displayed the highest DPPH free radical scavenging activity and ABTS decolorization assays. Whereas wild honey produced by A.nuluensis collected from the Chestnut tree extracted using 80% methanol displayed the highest FRAP activity. The wild honey produced by A. nuluensis also displayed the highest acetylcholinesterase properties as the antioxidant compounds contributed to the inhibitory properties of the enzyme. Manuka honey (produced from tea tree) found to be higher in antioxidant and acetylcholinesterase properties as compared to all other samples. The same trend of bioactivity was also observed in absolute methanol extracts. Strong positive correlation was found between antioxidant and acetylcholinesterase activity. Therefore, honey has the potential as natural antioxidant and acetylcholinesterase inhibition sources with promising potential benefits to human’s health.
    Matched MeSH terms: Free Radicals
  12. Palur, Ravikant
    Medical Health Reviews, 2009;2009(1):15-42.
    MyJurnal
    The brain is considered the most eloquent organ in the human body as its activities impacts on all other systems. Though protected physically (in a bony covering), physiologically through the blood-CSF barrier (from invading organisms and toxins) and hemodynamically through the phenomenon of cerebral autoregulation; the brain is open to insults of various kinds which can critically damage this structure. Intracellular Ca++ accumulation, excessive activation of excitatory amino acid receptors, lipid peroxidation and free radical releaserelated damage are but a few of the pathological processes that occur at the neuronal level leading to damage. The mechanism by which the brain can be provided protection when it is in a compromised state or likely to be compromised is known as cerebral protection. There are various modalities of pharmacologic (use of barbiturates, etomidate, isoflurane, steroids, Ca++, corticosteroids etc) and non-pharmacologic therapies (hypothermia, hyperventilation, induced hypotension, electrophysiologic monitoring, endovascular management etc) available for cerebral protection which finds place in the armamentarium of clinicians managing the critically injured brain. Our knowledge of the functioning of the brain at the molecular level and the various biochemico-pathological processes that are set into motion during critical states continues to evolve. This review article attempts to explain present understanding of the biochemical and pathological processes involved in neuronal damage while also looking at current available therapies (pharmacologic & nonpharmacologic) being utilized in different clinical settings.
    Matched MeSH terms: Free Radicals
  13. Lusia Barek, M., Hasmadi, M., Zaleha, A.Z., Mohd Fadzelly, A.B.
    MyJurnal
    Clinacanthus nutans (Burm. F.) Lindau or locally known in Sabah, Malaysia as ‘Sabah Snake Grass’ has been ethnobotanically used to treat various diseases in Asian countries. This study was conducted to determine the total phenolics content (TPC), flavonoids content (TFC) and antioxidant activity of herbal teas developed from C. nutans leaves with different drying techniques (microwave-oven dried and freeze dried) and infusion time (1, 2, 5, 10, 15 and 20 min). Ferric reducing/antioxidant power (FRAP) assay, 2,2’-azino-bis(3-ethylbenzothiazoline- 6-sulphonic acid (ABTS) and 2, 2-diphenyl-1-pycryl-hydrazyl (DPPH) free radical scavenging assays were used to investigate the antioxidant capacity. The highest TPC of herbal tea was observed in 20 min infusion of unfermented microwave-oven dried leaves (177.80 ± 19.10 mg TAE/L), while the highest TFC was observed in 10 min infusion of fermented microwave-oven dried leaves (22.13 ± 1.53 mg CE/L). Short infusion times from 5 min to 15 min were able to extract high amount of phenolics compounds. Unfermented tea contained higher TPC content (P < 0.05) as compared to fermented tea, while, TFC showed no significant difference between both types. Freeze dried infusion shows no significant difference (P > 0.05) as compared to microwave-oven dried for TPC, TFC and antioxidant capacity. Moderate and low correlation was observed between TPC and FRAP values (r = 0.507) and between TFC and ABTS values (r = 0.256). Preparation of C. nutans herbal tea as potential natural antioxidant source can be used as a basic reference for future research on the dietary intake of these herbal teas.
    Matched MeSH terms: Free Radicals
  14. Nurhuda, H.H., Maskat, M.Y., Mamot, S., Afiq, J., Aminah, A.
    MyJurnal
    Rambutan (Nephelium lappaceum) peel is a potential source of antioxidant. As rambutan is a seasonal fruit, a proper heat treatment prior to storage is necessary. Thus, this study was conducted to determine the effect of water and steam blanchings on browning enzymes and antioxidant activities of rambutan peel extracts. Rambutan from the variety of ‘Anak Sekolah’ were peeled and the peel was blanched in boiling water for 0, 2.5, 5 min and by autoclaving for 0, 5, 10 and 15 min. The residual peroxidase (POD) and polyphenoloxidase (PPO) activities, antioxidant activity (2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity), total polyphenol content (TPC) and peel extract colour were determined. The results showed that both water and steam blanchings significantly reduced (p < 0.05) POD and PPO activities. The results also indicated that the increase in the blanching period did not significantly reduce the enzyme activities further. In terms of antioxidant activity, the thermal pretreatment caused no significant difference in the contents of phenolic compounds, as well as the antioxidant capacity of the final product.
    Matched MeSH terms: Free Radicals
  15. Lim, S.M., Loh, S.P.
    MyJurnal
    This study aims to determine the antioxidant capacities (AC) and antidiabetic properties of
    phenolic extracts (free and bound) from white Tambun pomelo peels, kaffir lime peels, lime
    peels and calamansi peels. AC, total phenolic content (TPC) and antidiabetic properties of
    selected citrus peels extracts were determined spectrophotometrically using 2,2-Diphenyl-1-
    picrylhydrazyl free radical (DPPH) scavenging, ferric-reducing antioxidant power (FRAP),
    Folin-Ciocalteu (FC) and α-amylase and α-glucosidase inhibition assay, respectively. This
    study found that the methanolic extract of kaffir lime showed the best AC with the lowest
    IC50 value of DPPH radical (7.51 ± 0.50 mg/ml) and highest FRAP value [369.48 ± 20.15
    mM Fe (II) E/g DW]. TPC of free phenolic extracts of all citrus peels were significantly (p<
    0.05) higher compared to the bound phenolic extracts with extract of calamansi showed the
    highest TPC. Free- and bound phenolic extract of calamansi also had the highest α-amylase
    inhibition activity (61.79 ± 4.13%; 45.30 ± 5.35%) respectively. The highest inhibitory effect in
    α-glucosidase inhibition assay of free- and bound phenolic extracts were white Tambun pomelo
    (41.06 ± 10.94%) and calamansi (43.99 ± 22.03%) respectively. Hence, the citrus peels could
    be furthered study for their potential in management and/or prevention of diabetes.
    Matched MeSH terms: Free Radicals
  16. Ab. Rahman, N.S., Abd. Majid F.A., Harisun, Y., Md. Salleh L.
    MyJurnal
    Effects of different types of solvent on the antioxidant and antibacterial activity of Quercus infectoria extract have not been well documented. Therefore, extraction process was conducted using conventional Soxhlet extraction with six different types of solvent (100% methanol, ethanol, acetone, water and 70% methanol, and ethanol). High performance liquid chromatography was implemented to identify gallic acid and tannic acid in the extracts. Water extracts contained the highest concentration of both gallic acid and tannic acid compared to other types of solvent; 51.14 mg/g sample and 1332.88 mg/g sample of gallic acid and tannic acid. Meanwhile, antioxidant and antibacterial activity were tested using DPPH free radicals scavenging and disc diffusion assay. Results demonstrated that water extracts gave the highest antioxidant activity (approximately 94.55%), while acetone extract gave the largest inhibition zone for disc diffusion assay (19.00mm respectively). The results also revealed rich sources of gallic acid and tannic acid in Q. infectoria which might provide a novel source of these natural antioxidant and antibacterial activity.
    Matched MeSH terms: Free Radicals
  17. Normala, H., Suhaimi, M.I.
    MyJurnal
    One of the compounds present in Pluchea indica extracts is antioxidant which plays an important role in inhibiting free radicals and thus protects humans against infections and degenerative diseases, such as cancer, arthritis, and ageing process. The main objective of this study was to investigate and determine the total phenolic compounds of Pluchea indica in different concentrations of ethanolic extracts. This species was chosen because of its high phytonutrient compounds with potential medicinal properties. There was a significant difference (P ≤ 0.05) in the total phenolic among the different parts of the tested plant. 50% of the ethanolic extract produced the highest total phenolic compounds (1775.00±86.00 to 658.95±5.00 µmol/g), followed by water extract (759.79±1.53 µmol/g) and 100% ethanol extract (352.72±22.30 to 249.29±5.37 µmol/g), respectively. In terms of the plant parts, the leaves contained the highest phenolic compounds (1775.00±86.00 µmol/g in 50% ethanol extract, 759.79±1.53 µmol/g in 100% aqueous extract and 352.72±22.30 µmol/g in 100% ethanol extract), followed by the stems (990.22±24.00 µmol/g in 50% ethanol extract, 990.22±24.59 µmol/g in 100% aqueous extract and 293.48±0.00 µmol/g in 100% ethanol extract). Meanwhile, lower total phenolic compounds were detected in the flowers (727.71±11.00 µmol/g in 50% ethanol extract, 603.81±8.46 µmol/g in 100% aqueous extract and 249.29±5.37 µmol/g in 100% ethanol extract) and roots (658.95±5.00 µmol/g in 50% ethanol extract, 450.00±10.76 µmol/g in 100% aqueous extract and 272.28±0.53 µmol/g in 100% ethanol extract). Based on these findings, Pluchea indica has potential medicinal properties that can be further developed to produce neutraceutical products, diet supplements or cosmetic products. However, further research should first be conducted on the effects of these compounds on laboratory animals.
    Matched MeSH terms: Free Radicals
  18. Hani Hafeeza Halim, Mohd Sabri Pak Dek, Azizah Abdul Hamid, Ahmad Haniff Jaafar
    MyJurnal
    Among athletes, endurance is one of the key elements to victory. In addition to
    training, athletes normally used supplement to prevent fatigue during the event. With
    prolonged and intense activity, our body started to experience decrease in muscle
    performance due to several factors such as oxidative stress, dehydration and
    accumulation of lactic acid in the body fluids. The free radicals generated during
    intense exercise will expose the cells to oxidative damages. In the event of
    dehydration, there will be significant losses of water and functional electrolytes during
    intense exercise which affected the body fluid balance. Fatigue will also occur during
    reduced oxygen in aerobic metabolism which later caused accumulation of lactic acid
    in the muscle. This will change the pH balance toward more acidic and caused the
    muscles to lose contractile efficiency. In addition, fatigue can also be studied using rats
    as model organism. Results from this activity can be useful to analyse cellular
    metabolism and physiology effects of the tested rats toward physical exercise.
    Therefore, this review aims to discuss the causes of fatigue through oxidative stress,
    dehydration and lactic acid accumulation. In addition, the effectiveness of using rats as
    a model system in measuring fatigue is also included in illustrating examples on fatigue
    assessment in vivo.
    Matched MeSH terms: Free Radicals
  19. Azizah, A.H., Wee, K.C., Azizah, O., Azizah, M.
    MyJurnal
    Effect of various cooking methods on antioxidant content and radical scavenging activity of pumpkin was evaluated. Pumpkin (Cucurbita moschata) was boiled and stir-fried for 2, 4 and 6 minutes respectively. Beta-carotene and lycopene were determined using HPLC and total phenolics measured using Folin-Ciocalteu method. The free radical scavenging activity of the samples was determined using 1, 1-diphenyl-2 picrylhydrazyl assay. Interestingly, result of the study showed an increase in both beta-carotene (2 to 4 times) and lycopene (17 to 40 times) content of pumpkin after cooking for 2, 4 and 6 minutes. However, the treatment resulted in 18 to 54% losses of total phenolics content of the pumpkin. Nevertheless, the free radical scavenging activity exhibited by cooked pumpkins was found to be high, in the range of 81.1% to 94.6% with IC50 of 1.41 to 1.62 mg ml-1
    .
    Matched MeSH terms: Free Radicals
  20. Al-Juhaimi F, Ghafoor K, Özcan MM, Jahurul MHA, Babiker EE, Jinap S, et al.
    J Food Sci Technol, 2018 Oct;55(10):3872-3880.
    PMID: 30228385 DOI: 10.1007/s13197-018-3370-0
    Bioactive compounds from plant sources are generally categorized as natural antioxidants with well-known health benefits. The health-promoting characteristics of natural antioxidants include anti-inflammatory, anti-diabetic, and hepatic effects as well as free radical scavenging. Herein, a comprehensive and comparative review are presented about the effects of conventional (thermal and mechanical) and relatively new (non-thermal) processing methods on phytochemicals and discussed the importance of implementing the use of those methods that could be of very helpful retaining the quality of the bioactive compounds in plant-based foods. Plant-based foods rich in phenolics, vitamin C, carotenoids, and other compounds undergo a range of processing operations before they are consumed. Most of these methods involve thermal treatments of fruits, stems, leaves, and roots. These techniques have varying effects on bioactive compounds and their activities, and the magnitude of these effects depends on process parameters such as temperature, time, and the food matrix. Thermal processing can be detrimental to bioactive compounds while nonthermal procedures may not cause significant deterioration of important health-promoting phytochemicals and in some cases can improve their bio-activity and bio-availability. The detrimental effects of conventional processing on the quality of natural antioxidants have been compared to the effects of innovative nonthermal food treatments such as gamma and ultraviolet irradiation, ultraviolet light, pulsed electric fields, and high hydrostatic pressure.
    Matched MeSH terms: Free Radicals
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