Displaying publications 1 - 20 of 127 in total

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  1. Li Y, Dong L, Liu Y, Chen Q, Wu Z, Liu L, et al.
    Food Chem, 2024 Mar 01;435:137572.
    PMID: 37778268 DOI: 10.1016/j.foodchem.2023.137572
    The effects of covalent binding of protocatechuic acid (PA) and gallic acid (GA) to lactoferrin (LF) on the structure, functional, and antioxidant properties of the protein conjugate were investigated. These protein-phenolic conjugates were produced by laccase cross-linking and ultrasound-assisted free radical grafting, which were characterized using turbidity, particle size, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analyses. Structural changes in conjugates were monitored by endogenous fluorescence spectroscopy, fourier transform infrared spectroscopy (FTIR), and circular dichroism (CD). The antioxidant capacities and pH stability were determined using DPPH, ABTS, FRAP, and potentiometric analysis. The enzymatic cross-linking and free radical grafting yielded LF-PA/GA conjugates with altered hydrodynamic diameter and zeta-potential. Spectroscopic and chromatographic analyses revealed that binding to PA/GA altered the molecular structure of LF, with a decrease in LF isoelectric point post binding to PA/GA, without affecting antioxidant activities. In conclusion, LF-PA/GA conjugates present potential applications in the food industry.
    Matched MeSH terms: Free Radicals
  2. Summpunn P, Panpipat W, Manurakchinakorn S, Bhoopong P, Cheong LZ, Chaijan M
    Molecules, 2022 Aug 14;27(16).
    PMID: 36014418 DOI: 10.3390/molecules27165180
    Indigenous southern Thai non-glutinous rice varieties Kaab Dum, Khai Mod Rin, Yar Ko, Yoom Noon, and Look Lai made under four different processing conditions, white rice, brown rice, germinated brown rice, and rice grass, were assessed for antioxidant components and in vitro antioxidative activities. According to the findings, rice’s antioxidant components and antioxidant activity were considerably impacted by both variety and processing. High levels of total extractable phenolic compounds (164−314 mg gallic acid equivalent (GAE)/kg, dry weight (dw)) and carotenoid (0.92−8.65 mg/100 g, dw) were found in all rice varieties, especially in rice grass and germinated brown rice, indicating that milling to generate white rice had an adverse effect on those components. Additionally, after germination, a higher γ-oryzanol concentration (9−14 mg/100 g, dw) was found. All rice varieties had higher ascorbic acid, phenolic compound, and carotenoid contents after sprouting. Overall, Yoom Noon rice grass had the highest total extractable phenolic content (p < 0.05). The rice grass from Yoom Noon/Look Lai/Kaab Dum had the highest ascorbic acid content (p < 0.05). The total carotenoid concentration of Look Lai rice grass was the highest, and Yoom Noon’s germinated brown rice had the highest γ-oryzanol content (p < 0.05). All rice varieties’ aqueous extracts had remarkable ABTS free radical scavenging activity, with Khai Mod Rin reaching the highest maximum value of 42.56 mmol Trolox equivalent/kg dw. Other antioxidant mechanisms, however, were quite low. Compared to germinated brown rice, brown rice, and white rice, rice grass often tended to have stronger antioxidant activity. Yar Ko rice grass was found to have the highest DPPH free radical scavenging activity (3.8 mmol Trolox equivalent/kg dw) and ferric reducing antioxidant power (FRAP) (4.6 mmol Trolox equivalent/kg dw) (p < 0.05). Khai Mod Rice grass had the most pronounced metal chelation activity (1.14 mmol EDTA equivalent/kg dw) (p < 0.05). The rice variety and processing conditions, therefore, influenced the antioxidant compounds and antioxidative properties of Thai indigenous rice. The results can be used as a guide to select the optimal rice variety and primary processing in order to satisfy the needs of farmers who want to produce rice as a functional ingredient and to promote the consumption of indigenous rice by health-conscious consumers.
    Matched MeSH terms: Free Radicals
  3. Shi L, Liu J, Gao B, Sillanpää M
    Sci Total Environ, 2022 Mar 20;813:152397.
    PMID: 34923007 DOI: 10.1016/j.scitotenv.2021.152397
    The generation of free radicals is the key to the photocatalytic efficiency. In this study, the degradation mechanism of photoelectrocatalysis (PEC) membrane could be adequately explained by exploring the generation pathway of different free radicals. The PEC membrane was prepared by gas phase polymerization of poly (3, 4-ethylene dioxythiophene) (PEDOT) on non-woven fabric, industrial filter cloth, ceramic membrane and polyvinylidene fluoride (PVDF) membrane, respectively. Three-dimensional fluorescence test showed that the optimal degradation of mixed or monomer contamination (bovine serum protein, sodium humate, and sodium alginate) was achieved by modified ceramic membrane under PEC condition. As for self-cleaning experiment, the membrane resistance decreased 65.7% when the reaction conditions changed from dark to PEC for 30 min. Combined with the characterization results, PEDOT as photocapacitance extended electron lifetime and promoted free radical generation. This system was mainly dependent on superoxide free radicals (0.01 mmol/L) and singlet oxygen (0.10 mmol/L), which came from energy and electron transfer. Oxygen vacancy could adsorb oxygen to produce superoxide radicals, which was further oxidized to singlet oxygen. In addition, the π-electron conjugated system of PEDOT accelerated the hole transfer and the separation of electrons and holes. Also, this study provided a new view of reactive oxygen species generation mechanism from PEDOT modified membrane.
    Matched MeSH terms: Free Radicals
  4. Rahman ML, Wong ZJ, Sarjadi MS, Joseph CG, Arshad SE, Musta B, et al.
    Polymers (Basel), 2021 May 06;13(9).
    PMID: 34066308 DOI: 10.3390/polym13091486
    Toxic metals in the industrial wastewaters have been liable for drastic pollution hence a powerful and economical treatment technology is needed for water purification. For this reason, some pure cellulosic materials were derived from waste fiber to obtain an economical adsorbent for wastewater treatment. Conversion of cellulose into grafting materials such as poly(methyl acrylate)-grafted cellulose was performed by free radical grafting process. Consequently, poly(hydroxamic acid) ligand was produced from the grafted cellulose. The intermediate products and poly(hydroxamic acid) ligand were analyzed by FT-IR, FE-SEM, TEM, EDX, and XPS spectroscopy. The adsorption capacity (qe) of some toxic metals ions by the polymer ligand was found to be excellent, e.g., copper capacity (qe) was 346.7 mg·g-1 at pH 6. On the other hand, several metal ions such as cobalt chromium and nickel also demonstrated noteworthy sorption capacity at pH 6. The adsorption mechanism obeyed the pseudo second-order rate kinetic model due to the satisfactory correlated experimental sorption values (qe). Langmuir model isotherm study showed the significant correlation coefficient with all metal ions (R2 > 0.99), indicating that the single or monolayer adsorption was the dominant mode on the surface of the adsorbent. This polymer ligand showed good properties on reusability. The result shows that the adsorbent may be recycled for 6 cycles without any dropping of starting sorption capabilities. This polymeric ligand showed outstanding toxic metals removal magnitude, up to 90-99% of toxic metal ions can be removed from industrial wastewater.
    Matched MeSH terms: Free Radicals
  5. Alam I, Forid MS, Roney M, Aluwi MFFM, Huq AM
    Data Brief, 2021 Apr;35:106839.
    PMID: 33659597 DOI: 10.1016/j.dib.2021.106839
    The current data report describes the predictive identification of phytochemical constituents in the bioactive extract of Ipomoea mauritiana (IM) whole plant. For several formulations this plant was commonly used as 'Vidari' for Ayurvedic medicine. Traditionally, IM tubers are used to alleviate spinal cord pain, improve breast milk, as a tonic, increase sperm count and treating jaundice. The methanol extract can potentially scavenge free radicals and possess antibacterial activity that could be correlated with its chemical composition. So it is crucial to identify the major compounds of IM. An ultra-performance liquid chromatography coupled electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC-ESI-QTOF/MS) method was adopted to detect the flavonoids, saponins, alkaloids, terpenoids in IM methanol extract. Data presented here is related to a published work Antioxidant and antibacterial activity of Ipomoea mauritiana Jacq.: A traditionally used medicinal plant in Bangladesh (Alam et al., 2020). Secondary metabolites were analyzed by the comparison of the mass fragmentation arrangements with Waters UNIFI library that enables for positive identification of the compounds based on the spectral match.
    Matched MeSH terms: Free Radicals
  6. 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
  7. Sivasothy Y, Leong KH, Loo KY, Adbul Wahab SM, Othman MA, Awang K
    Nat Prod Res, 2021 Feb 16.
    PMID: 33593208 DOI: 10.1080/14786419.2021.1885405
    The use of antidiabetic agents which control glycemic levels in the blood and simultaneously inhibit oxidative stress is an important strategy in the prevention of Diabetes Mellitus and its complications. In our previous study, malabaricone C (3) and its dimer, giganteone A (5) exhibited significant DPPH free radical scavenging activities which were lower than the activity of the positive control, ascorbic acid. These compounds were evaluated for their α-glucosidase inhibitory activities at different concentrations (0.02-2.5 mM) in the present study. Compounds 3 (IC50 59.61 µM) and 5 (IC50 39.52 µM) were identified as active alpha-glucosidase inhibitors, each respectively being 24 and 37 folds more potent than the standard inhibitor, acarbose. Based on the molecular docking studies, compounds 3 and 5 docked into the active site of the α-glucosidase enzyme, forming mainly hydrogen bonds in the active site.
    Matched MeSH terms: Free Radicals
  8. Rehman U, Sarfraz RM, Mahmood A, Hussain Z, Thu HE, Zafar N, et al.
    Curr Drug Deliv, 2021 Feb 11.
    PMID: 33583374 DOI: 10.2174/1567201818666210212085912
    BACKGROUND: Despite exhibiting promising anticancer potential, the clinical significance of capecitabine (a potent prodrug of 5-fluorouracil used for treatment of colorectal cancer) is limited owing to its acidic and enzymatic hydrolysis, lower absorption following the oral administration, poor bioavailability, short plasma half-life and poor patient compliance.

    OBJECTIVES: The present study was aimed to fabricate the capecitabine as smart pH-responsive hydrogel network to efficiently facilitate its oral delivery while shielding its stability in the gastric media.

    METHODS: The smart pH sensitive HP-β-CD/agarose-g-poly(MAA) hydrogel network was developed using an aqueous free radical polymerization technique. The developed hydrogels were characterized for drug-loading efficiency, structural and compositional features, thermal stability, swelling behaviour, morphology, physical form, and release kinetics. The pH-responsive behaviour of developed hydrogels was established by conducting the swelling and release behaviour at different pH values (1.2 and 7.4), demonstrating significantly higher swelling and release at pH 7.4 as compared with pH 1.2. The capecitabine-loaded hydrogels were also screened for acute oral toxicity in animals by analysing the body weight, water and food intake, dermal toxicity, ocular toxicity, biochemical analysis, and histological examination.

    RESULTS: The characteristic evaluations revealed that capecitabine (anticancer agent) was successfully loaded into the hydrogel network. Capecitabine loading was ranged from 71.22% to 90.12%. An interesting feature of hydrogel was its pH-responsive behaviour which triggers release at basic pH (94.25%). Optimum swelling (95%) was seen at pH 7.4. Based upon regression coefficient R2 (0.96 - 0.99) best fit model was zero order. The extensive toxicity evaluations evidenced good safety profile with no signs of oral, dermal or ocular toxicities, as well as no variations in blood parameters and histology of vital organs.

    CONCLUSION: Our findings conclusively evinced that the developed hydrogel exhibited excellent pharmaceutical and therapeutic potential and thus can be employed as pH-responsive system for controlled delivery of anticancer agents.

    Matched MeSH terms: Free Radicals
  9. Saraswati, Giriwono PE, Iskandriati D, Tan CP, Andarwulan N
    Food Res Int, 2020 Nov;137:109702.
    PMID: 33233276 DOI: 10.1016/j.foodres.2020.109702
    Sargassum brown seaweed is well-known to contain several bioactive compounds which exhibit various biological activities, including anti-inflammatory and antioxidant activity. Lipophilic extracts and fractions of Sargassum were reported to possess promising anti-inflammatory activity. This study, therefore, aims to evaluate the anti-inflammatory and antioxidant activity of Sargassum cristaefolium crude lipid extract and its fractions. The brown seaweed was obtained from Awur Bay, Jepara - Indonesia. Crude lipid fractionation was performed using normal phase column chromatography, and three different fractions (dichloromethane, acetone, methanol) were produced. The results showed that treatment of acetone fraction exerted strongest nitric oxide inhibition in lipopolysaccharide-induced RAW 264.7 cells, both in pre-incubated and co-incubated cell culture models. This outcome was in accordance with its 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and ferric reducing antioxidant power (FRAP). Metabolite profiling of lipid fractions was performed by ultra-high-performance liquid chromatography electrospray ionization orbitrap tandem mass spectrometry, while the orthogonal projection to latent structures analysis was conducted to determine some features with significant correlation to the bioactivity. There were 14 feature candidates considered from both positive and negative ionization mode datasets. Seven out of them were putatively identified as pheophytin a (1), all-trans fucoxanthin (2), 132-hydroxy-pheophytin a (3), pheophorbide a (4), 1-hexadecanoyl-2-(9Z-octadecenoyl)-3-O-β-D-galactosyl-sn-glycerol (6), 1-(5Z,8Z,11Z,14Z,17Z-eicosapentaenoyl)-2-(9Z,12Z,15Z-octadecatrienoyl)-3-O-β-D-galactosyl-sn-glycerol (10), and 1-(9Z,12Z,15Z-octadecatrienoyl)-2-(6Z,9Z,12Z,15Z-octadecatetraenoyl)-3-O-β-D-galactosyl-sn glycerol (12).
    Matched MeSH terms: Free Radicals
  10. Shaker LM, Al-Amiery AA, Kadhum AAH, Takriff MS
    Nanomaterials (Basel), 2020 Oct 15;10(10).
    PMID: 33076278 DOI: 10.3390/nano10102028
    Many people suffer from myopia or hyperopia due to the refractive errors of the cornea all over the world. The use of high refractive index (RI), Abbe number (νd), and visible light transmittance (T%) polymeric contact lenses (CLs) holds great promise in vision error treatment as an alternative solution to the irreversible laser-assisted in situ keratomileusis (LASIK) surgery. Titanium dioxide nanoparticles (TiO2 NPs) have been suggested as a good candidate to rise the RI and maintain high transparency of a poly(methyl methacrylate) (PMMA)-TiO2 nanocomposite. This work includes a preparation of TiO2 NPs using the sol gel method as well as a synthesis of pure PMMA by free radical polarization and PMMA-TiO2 CLs using a cast molding method of 0.005 and 0.01 w/v concentrations and a study of their effect on the aberrated human eye. ZEMAX optical design software was used for eye modeling based on the Liou and Brennan eye model and then the pure and doped CLs were applied. Ocular performance was evaluated by modulation transfer function (MTF), spot diagram, and image simulation. The used criteria show that the best vision correction was obtained by the CL of higher doping content (p < 0.0001) and that the generated spherical and chromatic aberrations in the eye had been reduced.
    Matched MeSH terms: Free Radicals
  11. 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
  12. Sutirman ZA, Rahim EA, Sanagi MM, Abd Karim KJ, Wan Ibrahim WA
    Int J Biol Macromol, 2020 Jun 15;153:513-522.
    PMID: 32142849 DOI: 10.1016/j.ijbiomac.2020.03.015
    A new crosslinked chitosan grafted with methyl methacrylate (M-CTS) adsorbent was synthesized via free radical polymerization for effective removal of Cu(II) ions from aqueous solution. Crosslinked chitosan (1 g) was grafted with 29.96 × 10-1 M methyl methacrylate in the presence of 2.63 × 10-1 M ammonium persulfate as initiator at 60 °C for 2 h to give grafting and yield percentages of 201% and 67%, respectively. Batch adsorption experiment was performed as a function of solution pH, initial metal ion concentration and contact time. The isotherm data were adequately described by Langmuir model, while kinetic study revealed that the pseudo-second order rate model best fitted for the experimental data. The maximum adsorption capacity for M-CTS at pH 4 was 192.31 mg g-1. Furthermore, the reusability of over six adsorption-desorption cycles suggested that M-CTS is a durable adsorbent and good candidate for metal ions treatment.
    Matched MeSH terms: Free Radicals
  13. 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
  14. Siti Radhiah Omar, Fauzan Aminuddin, Latiffah Karim, Nursyahida Suhaimi, Siti Nazirah Omar
    MyJurnal
    This research aimed to determine the total antioxidant activity and total phenolic content of the papaya
    seeds. These papaya seeds then were introduced into the prepared ice cream to determine the effect of the
    papaya seeds to the physicochemical and the acceptability of ice cream by making four different
    formulations (Control, 1.0%, 2.0%, and 3.0% of papaya seeds). Two methods namely free radical
    scavenging assay (DPPH) and ferric reducing antioxidant power (FRAP) were used to determine the total
    antioxidant activity of the papaya seeds, whereas total phenolic content was determined by FolinCiocalteu’s method (TPC). The papaya seeds showed high total phenolic content in the TPC analysis result.
    Furthermore, DPPH and FRAP showed high antioxidant activity of the papaya seeds. Acceptability of the
    ice cream was conducted by sensory evaluation and the results showed that the control (0.0%) papaya seeds
    ice cream formulation was the most favorable by the panelists followed by 1.0%, 2.0%, and 3.0% papaya
    seeds formulation. In conclusion, the papaya seeds are proven to contain antioxidants by the results given
    in DPPH, FRAP, and TPC tests. Surprisingly, the papaya seeds also did not affect the physicochemical of
    the ice cream and the ice cream was accepted by the panelists.
    Matched MeSH terms: Free Radicals
  15. Selvaraja M, Chin VK, Abdullah M, Arip M, Amin-Nordin S
    Front Med (Lausanne), 2020;7:598665.
    PMID: 33644084 DOI: 10.3389/fmed.2020.598665
    Systemic lupus erythematosus (SLE) is a chronic autoimmune disease afflicting multiple organs. Lupus nephritis (LN) is a serious complication of SLE and remains a major cause of mortality and morbidity. Curative therapy remains unavailable as etiology from genetic and environmental factors is still unclear. The present study was conducted to elucidate the link between HLA-DRB1 gene polymorphisms with SLE and LN through clinical and laboratory/biological presentations in a population of Malaysian Malay females with SLE. A total of 100 Malay female SLE patients inclusive of 70 SLE patients without LN and 30 patients with LN were included in this study. HLA-DRB1 allele examination in SLE patients was performed using PCR-SSO, and the alleles' frequencies were compared with 951 publicly available datasets representing Malay healthy controls in Malaysia. Cytokines and free radical levels were detected by ELISA and bead-based multiplexed Luminex assays. The association between HLA-DRB1 alleles with clinical and serological manifestations and immune mediators was analyzed using different statistical approaches whenever applicable. Our study showed that HLA-DRB1*0405, HLA-DRB1*1502, and HLA-DRB1*1602 were associated with the increased risk of SLE while HLA-DRB1*1201 and HLADRB1*1202 alleles were associated with a lower risk of SLE development. Furthermore, HLA-DRB1*04 showed significant association to LN and arthritis while HLA-DRB1*15 was significantly associated with oral ulcer in Malay SLE patients. Association analysis of HLA-DRB1*04 with clinical and biological factors revealed that HLA-DRB1*04 was significantly associated with Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) scores, anti-nuclear antibody (ANA), C-reactive protein (CRP) in the blood, and total protein in the urine. SLE carriers with the HLA-DRB1*04 allele were significantly correlated to the increased levels of cytokines (IFN-y, GM-CSF, IL-17F, IL-18, IL-21, and VEGF) and were significantly showing negative correlation to IL-5 and free radicals (LPO and catalase enzyme) levels compared to SLE carriers without HLA-DRB1*04 allele. The results suggested that disease severity in SLE may be determined by HLA-DRB1 alleles. The risk of HLA-DRB1*04 allele with LN was supported by the demonstration of an intense inflammatory response in Malay SLE patients in Malaysia. More studies inclusive of a larger and multiple SLE cohorts in the future are warranted to validate these findings.
    Matched MeSH terms: Free Radicals
  16. Sallehuddin, N. A., Azizah Abdul Hamid, Salleh, S. Z., Nazia Abdul Majid, Hani Hafeeza Halim, Nurul Shazini Ramli, et al.
    MyJurnal
    In the present work, aqueous ethanolic (60% ethanol) extracts from selected Malaysian herbs
    including Murraya koenigii L. Spreng, Lawsonia inermis L., Cosmos caudatus Kunth, Piper
    betle L., and P. sarmentosum Roxb. were evaluated for their ergogenic, anti-diabetic and
    antioxidant potentials. Results showed that the analysed herbs had ergogenic property and
    were able to activate 5'AMP-activated protein kinase (AMPK) in a concentration dependant
    manner. The highest AMPK activation was exhibited by M. koenigii extract which showed no
    significant (p > 0.05) difference with green tea (positive control). For anti-diabetic potential,
    the highest α-glucosidase inhibition was exhibited by M. koenigii extract with IC50 of 43.35
    ± 7.5 µg/mL, which was higher than acarbose (positive control). The determinations of free
    radical scavenging activity and total phenolics content (TPC) indicated that the analysed herbs
    had good antioxidant activity. However, C. caudatus extract showed superior antioxidant
    activity with IC50 against free radical and TPC of 21.12 ± 3.20 µg/mL and 221.61 ± 7.49 mg
    GAE/g, respectively. RP-HPLC analysis established the presence of flavonoids in the herbs
    wherein L. inermis contained the highest flavonoid (catechin, epicatechin, naringin and rutin)
    content (668.87 mg/kg of extract). Correlations between the analyses were conducted, and
    revealed incoherent trends. Overall, M. koenigii was noted to be the most potent herb for
    enhancement of AMPK activity and α-glucosidase inhibition but exhibited moderate antioxidant activity. These results revealed that the selected herbs could be potential sources of
    natural ergogenic and anti-diabetic/antioxidant agents due to their rich profile of phenolics.
    Further analysis in vivo should be carried out to further elucidate the mechanism of actions of
    these herbs as ergogenic aids and anti-diabetic/antioxidant agents.
    Matched MeSH terms: Free Radicals
  17. Nur Syafiqah Martang, Nadia Majitol, Farnidah Jasnie, Lo Chor-Wai
    Borneo Akademika, 2020;4(4):15-20.
    MyJurnal
    Most of the plants in the ginger family Zingeberaceae are well-known for their medicinal properties. However, the genus Hornstedtia found in Sabah is less reported. This research aims to investigate the phytochemical constituent and vitamin C content of a fruit, locally known as the Tolidus fruit in Sabah. The dried fruit sample was extracted using three solvents which were water, ethanol and methanol. The phytochemical constituents were determined using standard Colour Test for the presence of alkaloid, flavonoid, saponin and tannin. Then, the content of Vitamin C was determined using the standard Colorimetric Titration and ascorbic acid as standard. The phytochemical evaluation revealed that all three targeted constituents were present in all extracts except for the alkaloid. The vitamin C content was determined in both dried and fresh sample of fruits, where 52.84 mg was quantified in the fresh fruit aqueous extract and 23.93 mg in the dried fruit aqueous extract respectively. These results are comparable to the content of vitamin C in orange and lime fruits. The phytochemical evaluation and vitamin C content of Tolidus suggested the potential of this underutilised fruit to be the natural and affordable source of vitamin C. Additionally, may protect the body against harmful free radicals. However, further analysis is needed to determine other constructive natural contents and evaluate the efficacy of this fruit as a natural source of antioxidant
    Matched MeSH terms: Free Radicals
  18. 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
  19. Kavi Rajan R, Hussein MZ, Fakurazi S, Yusoff K, Masarudin MJ
    Int J Mol Sci, 2019 Sep 20;20(19).
    PMID: 31547100 DOI: 10.3390/ijms20194667
    Naturally existing Chlorogenic acid (CGA) is an antioxidant-rich compound reported to act a chemopreventive agent by scavenging free radicals and suppressing cancer-causing mechanisms. Conversely, the compound's poor thermal and pH (neutral and basic) stability, poor solubility, and low cellular permeability have been a huge hindrance for it to exhibit its efficacy as a nutraceutical compound. Supposedly, encapsulation of CGA in chitosan nanoparticles (CNP), nano-sized colloidal delivery vector, could possibly assist in enhancing its antioxidant properties, in vitro cellular accumulation, and increase chemopreventive efficacy at a lower concentration. Hence, in this study, a stable, monodispersed, non-toxic CNP synthesized via ionic gelation method at an optimum parameter (600 µL of 0.5 mg/mL of chitosan and 200 µL of 0.7 mg/mL of tripolyphosphate), denoted as CNP°, was used to encapsulate CGA. Sequence of physicochemical analyses and morphological studies were performed to discern the successful formation of the CNP°-CGA hybrid. Antioxidant property (studied via DPPH (1,1-diphenyl-2-picrylhydrazyl) assay), in vitro antiproliferative activity of CNP°-CGA, and in vitro accumulation of fluorescently labeled (FITC) CNP°-CGA in cancer cells were evaluated. Findings revealed that successful formation of CNP°-CGA hybrid was reveled through an increase in particle size 134.44 ± 18.29 nm (polydispersity index (PDI) 0.29 ± 0.03) as compared to empty CNP°, 80.89 ± 5.16 nm (PDI 0.26 ± 0.01) with a maximal of 12.04 μM CGA loaded per unit weight of CNP° using 20 µM of CGA. This result correlated with Fourier-Transform Infrared (FTIR) spectroscopic analysis, transmission Electron Microscopy (TEM) and field emission scanning (FESEM) electron microscopy, and ImageJ evaluation. The scavenging activity of CNP°-CGA (IC50 5.2 ± 0.10 µM) were conserved and slightly higher than CNP° (IC50 6.4±0.78 µM). An enhanced cellular accumulation of fluorescently labeled CNP°-CGA in the human renal cancer cells (786-O) as early as 30 min and increased time-dependently were observed through fluorescent microscopic visualization and flow cytometric assessment. A significant concentration-dependent antiproliferation activity of encapsulated CGA was achieved at IC50 of 16.20 µM as compared to CGA itself (unable to determine from the cell proliferative assay), implying that the competent delivery vector, chitosan nanoparticle, is able to enhance the intracellular accumulation, antiproliferative activity, and antioxidant properties of CGA at lower concentration as compared to CGA alone.
    Matched MeSH terms: Free Radicals
  20. Hussin M, Abdul Hamid A, Abas F, Ramli NS, Jaafar AH, Roowi S, et al.
    Molecules, 2019 Sep 03;24(17).
    PMID: 31484470 DOI: 10.3390/molecules24173208
    Herbs that are usually recognized as medicinal plants are well known for their therapeutic effects and are traditionally used to treat numerous diseases, including aging. This study aimed to evaluate the metabolite variations among six selected herbs namely Curcurmalonga, Oenanthejavanica, Vitex negundo, Plucheaindica, Cosmoscaudatus and Persicariaminus using proton nuclear magnetic resonance (1H-NMR) coupled with multivariate data analysis (MVDA). The free radical scavenging activity of the extract was measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azinobis(3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS) and oxygen radical absorbance capacity (ORAC) assay. The anti-aging property was characterized by anti-elastase and anti-collagenase inhibitory activities. The results revealed that P. minus showed the highest radical scavenging activities and anti-aging properties. The partial least squares (PLS) biplot indicated the presence of potent metabolites in P. minus such as quercetin, quercetin-3-O-rhamnoside (quercitrin), myricetin derivatives, catechin, isorhamnetin, astragalin and apigenin. It can be concluded that P. minus can be considered as a potential source for an anti-aging ingredient and also a good free radical eradicator. Therefore, P. minus could be used in future development in anti-aging researches and medicinal ingredient preparations.
    Matched MeSH terms: Free Radicals
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