Displaying publications 61 - 80 of 157 in total

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  1. Fulltext Effect of Cadmium and Copper Exposure on Growth, Secondary Metabolites and Antioxidant Activity in the Medicinal Plant Sambung Nyawa (Gynura procumbens (Lour.) Merr)
    Ibrahim MH, Chee Kong Y, Mohd Zain NA
    Molecules, 2017 Oct 12;22(10).
    PMID: 29023367 DOI: 10.3390/molecules22101623
    A randomized complete block (RCBD) study was designed to investigate the effects of cadmium (Cd) and copper (Cu) on the growth, bioaccumulation of the two heavy metals, metabolite content and antibacterial activities in Gyanura procumbens (Lour.) Merr. Nine treatments including (1) control (no Cd and Cu); (2) Cd 2 = cadmium 2 mg/L; (3) Cd 4 = cadmium 4 mg/L; (4) Cu 70 = copper 70 mg/L; (5) Cu 140 = copper 140 mg/L); (6) Cd 2 + Cu 70 = cadmium 2 mg/L + copper 70 mg/L); (7) Cd 2 + Cu 140 = cadmium 2 mg/L + copper 70 mg/L); (8) Cd 4 + Cu 70 = cadmium 4 mg/L+ copper 70 mg/L and (9) Cd 4 + Cu 140 = cadmium 4 mg/L + copper 140 mg/L) were evaluated in this experiment. It was found that the growth parameters (plant dry weight, total leaf area and basal diameter) were reduced with the exposure to increased concentrations of Cd and Cu and further decreased under interaction between Cd and Cu. Production of total phenolics, flavonoids and saponin was observed to be reduced under combined Cd and Cu treatment. The reduction in the production of plant secondary metabolites might be due to lower phenyl alanine lyase (PAL) activity under these conditions. Due to that, the 1,1-diphenyl-2-picrylhydrazyl (DPPH), ferric reducing antioxidant potential (FRAP) and antibacterial activities was also found to be reduced by the combined treatments. The current experiments show that the medicinal properties of G. procumbens are reduced by cadmium and copper contamination. The accumulation of heavy metal also was found to be higher than the safety level recommended by the WHO in the single and combined treatments of Cd and Cu. These results indicate that exposure of G. procumbens to Cd and Cu contaminated soil may potentially harm consumers due to bioaccumulation of metals and reduced efficacy of the herbal product.
    Matched MeSH terms: Free Radical Scavengers/pharmacology; Free Radical Scavengers/chemistry
  2. Fulltext Nutritional profile and antioxidative properties of selected tropical wild vegetables
    Ng, X.N., Chye, F.Y., Mohd Ismail, A.
    International Food Research Journal, 2012;19(4):1487-1496.
    MyJurnal
    Five underutilized wild vegetables namely Limnophila aromaticoides, Ceratopetris thalictroides, Crassocephalum crepidioides, Etlingera elatoir and Monochoria vaginalis were analyzed for nutritional values, phenolic components and antioxidant activities. These wild greens were found to have high fibre (11.3-19.8 g/100g) and ash (13.0-17.6 g/100g) contents as compared to commercialized species, Brassica juncea. The iron content of Monochoria vaginalis is four times higher than Brassica juncea (33.1 mg/g dry weight). Crassocephalum crepidioides demonstrated remarkable lipid peroxidation inhibition (90.4%). The phenolic content of Etlingera elatoir is two times higher than Brassica juncea. Thus, it is of both great free radical scavenger and iron chelators with the lowest EC50 values of 1.8 mg/ml and 2.3 mg/ml respectively. As a conclusion, these wild vegetables could be potentially used in alleviating micronutrients deficiency especially for the rural populace and as a potent source of natural antioxidants.
    Matched MeSH terms: Free Radical Scavengers
  3. Fulltext The Role of N-Acetylcysteine Supplementation on the Oxidative Stress Levels, Genotoxicity and Lineage Commitment Potential of Ex Vivo Murine Haematopoietic Stem/Progenitor Cells
    Hamid ZA, Tan HY, Chow PW, Harto KAW, Chan CY, Mohamed J
    Sultan Qaboos Univ Med J, 2018 May;18(2):e130-e136.
    PMID: 30210840 DOI: 10.18295/squmj.2018.18.02.002
    Objectives: The ex vivo maintenance of haematopoietic stem/progenitor cells (HSPCs) is crucial to ensure a sufficient supply of functional cells for research or therapeutic applications. However, when exposed to reactive oxygen species (ROS) in a normoxic microenvironment, HSPCs exhibit genomic instability which may diminish their quantity and quality. This study aimed to investigate the role of N-acetylcysteine (NAC) supplementation on the oxidative stress levels, genotoxicity and lineage commitment potential of murine haematopoietic stem/progenitor cells (HSPCs).

    Methods: This study was carried out at the Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia, between June 2016 and July 2017. Bone marrow cells were isolated from nine mice and cultured in a growth medium. Various concentrations of NAC between 0.125-2 μM were added to the culture for 48 hours; these cells were then compared to non-supplemented cells harvested from the remaining three mice as the control group. A trypan blue exclusion test was performed to determine cell viability, while intracellular ROS levels and genotoxicity were determined by hydroethidine staining and comet assay, respectively. The lineage commitment potential of erythroid, myeloid and pre-B-lymphoid progenitor cells was evaluated via colony-forming cell assay.

    Results: NAC supplementation at 0.25, 0.5 and 2 μM significantly increased cell viability (P <0.050), while intracellular ROS levels significantly decreased at 0.25 and 0.5 μM (P <0.050). Moreover, DNA damage was significantly reduced at all NAC concentrations (P <0.050). Finally, the potential lineage commitment of the cells was not significantly affected by NAC supplementation (P >0.050).

    Conclusion: The findings of this study indicate that NAC supplementation may potentially overcome the therapeutic limitations of ex vivo-maintained HSPCs.

    Matched MeSH terms: Free Radical Scavengers/pharmacology*
  4. Fulltext Antioxidant Activities of 4-Methylumbelliferone Derivatives
    Al-Majedy YK, Al-Amiery AA, Kadhum AA, Mohamad AB
    PLoS One, 2016;11(5):e0156625.
    PMID: 27243231 DOI: 10.1371/journal.pone.0156625
    The synthesis of derivatives of 4-Methylumbelliferone (4-MUs), which are structurally interesting antioxidants, was performed in this study. The modification of 4-Methylumbelliferone (4-MU) by different reaction steps was performed to yield the target compounds, the 4-MUs. The 4-MUs were characterized by different spectroscopic techniques (Fourier transform infrared; FT-IR and Nuclear magnetic resonance; NMR) and micro-elemental analysis (CHNS). The in vitro antioxidant activity of the 4-MUs was evaluated in terms of their free radical scavenging activities against 2,2-diphenyl-1-picrylhydrazyl (DPPH), Nitric oxide radical scavenging activity assay, chelating activity and their (FRAP) ferric-reducing antioxidant power, which were compared with a standard antioxidant. Our results reveal that the 4-MUs exhibit excellent radical scavenging activities. The antioxidant mechanisms of the 4-MUs were also studied. Density Function Theory (DFT)-based quantum chemical studies were performed with the basis set at 3-21G. Molecular models of the synthesized compounds were studied to understand the antioxidant activity. The electron levels, namely HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital), for these synthesized antioxidants were also studied.
    Matched MeSH terms: Free Radical Scavengers/pharmacology; Free Radical Scavengers/chemistry*
  5. Fulltext The antioxidant activity of new coumarin derivatives
    Kadhum AA, Al-Amiery AA, Musa AY, Mohamad AB
    Int J Mol Sci, 2011;12(9):5747-61.
    PMID: 22016624 DOI: 10.3390/ijms12095747
    The antioxidant activity of two synthesized coumarins namely, N-(4,7-dioxo-2- phenyl-1,3-oxazepin-3(2H,4H,7H)-yl)-2-(2-oxo-2H-chromen-4-yloxy)acetamide 5 and N-(4-oxo-2-phenylthiazolidin-3-yl)-2-(2-oxo-2H-chromen-4-yloxy)acetamide 6 were studied with the DPPH, hydrogen peroxide and nitric oxide radical methods and compared with the known antioxidant ascorbic acid. Compounds 5 and 6 were synthesized in a good yield from the addition reaction of maleic anhydride or mercaptoacetic acid to compound 4, namely N'-benzylidene-2-(2-oxo-2H-chromen-4-yloxy)acetohydrazide. Compound 4 was synthesized by the condensation of compound 3, namely 2-(2-oxo-2H-chromen-4-yloxy) acetohydrazide, with benzaldehyde. Compound 3, however, was synthesized from the addition of hydrazine to compound 2, namely ethyl 2-(2-oxo-2H-chromen-4-yloxy)acetate, which was synthesized from the reaction of ethyl bromoacetate with 4-hydroxycoumarin 1. Structures for the synthesized coumarins 2-6 are proposed on the basis of spectroscopic evidence.
    Matched MeSH terms: Free Radical Scavengers/chemical synthesis*; Free Radical Scavengers/pharmacology; Free Radical Scavengers/chemistry
  6. Fulltext Hydrogen Peroxide Scavenging Activity of Novel Coumarins Synthesized Using Different Approaches
    Al-Amiery AA, Al-Majedy YK, Kadhum AA, Mohamad AB
    PLoS One, 2015;10(7):e0132175.
    PMID: 26147722 DOI: 10.1371/journal.pone.0132175
    New derivatives of 7-hydroxy-4-methylcoumarin were synthesized using a chemical method and a microwave-assisted method to compare the feasibility, reaction times, and yields of the product. The newly synthesized coumarins were characterized by different spectroscopic techniques (FT-IR and NMR) and micro-elemental analysis (CHNS). In vitro antioxidant activities of these compounds were evaluated against hydrogen peroxide and were compared with standard natural antioxidant, vitamin C. Our results reveal that these compounds exhibit excellent radical scavenging activities.
    Matched MeSH terms: Free Radical Scavengers/chemical synthesis*; Free Radical Scavengers/chemistry*
  7. Fulltext Novel macromolecules derived from coumarin: synthesis and antioxidant activity
    Al-Amiery AA, Al-Majedy YK, Kadhum AA, Mohamad AB
    Sci Rep, 2015;5:11825.
    PMID: 26134661 DOI: 10.1038/srep11825
    The rational design of 4-hydroxycoumarins with tailor-made antioxidant activities is required nowadays due to the wide variety of pharmacologically significant, structurally interesting of coumarins and researcher orientation toward green chemistry and natural products. A simple and unique coumarins have been achieved by reaction of 4-hydroxycoumarin with aromatic aldehyde accompanied with the creation of a macromolecules have 2-aminothiazolidin-4-one. The molecular structures of the compounds were characterized by the Fourier transformation infrared and Nuclear magnetic resonance spectroscopies, in addition to CHN analysis. The scavenging abilities of new compounds against stable DPPH radical (DPPH•) and hydrogen peroxide were done and the results show that the compounds exhibited high antioxidant activates.
    Matched MeSH terms: Free Radical Scavengers
  8. Fulltext Polyphenol Rich Ajuga bracteosa Transgenic Regenerants Display Better Pharmacological Potential
    Rubnawaz S, Kayani WK, Akhtar N, Mahmood R, Khan A, Okla MK, et al.
    Molecules, 2021 Aug 11;26(16).
    PMID: 34443462 DOI: 10.3390/molecules26164874
    Ajuga bracteosa Wall. ex Benth. is an endangered medicinal herb traditionally used against different ailments. The present study aimed to create new insight into the fundamental mechanisms of genetic transformation and the biological activities of this plant. We transformed the A. bracteosa plant with rol genes of Agrobacterium rhizogenes and raised the regenerants from the hairy roots. These transgenic regenerants were screened for in vitro antioxidant activities, a range of in vivo assays, elemental analysis, polyphenol content, and different phytochemicals found through HPLC. Among 18 polyphenolic standards, kaempferol was most abundant in all transgenic lines. Furthermore, transgenic line 3 (ABRL3) showed maximum phenolics and flavonoids content among all tested plant extracts. ABRL3 also demonstrated the highest total antioxidant capacity (8.16 ± 1 μg AAE/mg), total reducing power, (6.60 ± 1.17 μg AAE/mg), DPPH activity (IC50 = 59.5 ± 0.8 μg/mL), hydroxyl ion scavenging (IC50 = 122.5 ± 0.90 μg/mL), and iron-chelating power (IC50 = 154.8 ± 2 μg/mL). Moreover, transformed plant extracts produced significant analgesic, anti-inflammatory, anticoagulant, and antidepressant activities in BALB/c mice models. In conclusion, transgenic regenerants of A. bracteosa pose better antioxidant and pharmacological properties under the effect of rol genes as compared to wild-type plants.
    Matched MeSH terms: Free Radical Scavengers/chemistry
  9. Comparison of crude extract from durio zibethinus M. (durian) leaf waste via ultrasound-assisted extraction and accelerated solvent extraction: antioxidant activity and cytotoxicity
    Kam WJ, Abas F, Hussain N, Mirhosseini H
    Nat Prod Res, 2020 Jul;34(13):1937-1941.
    PMID: 30691284 DOI: 10.1080/14786419.2018.1564296
    The objective of this study was to compare the antioxidant activity and cytotoxicity of Durio zibethinus M. (Durian) leaf extract from two extraction methods. Ultrasound-assisted extraction and Accelerated-solvent extraction were used to produce crude extract. The results revealed that UAE achieved 3× higher in total phenolic content in the leaf extract compared to ASE. DPPH radical scavenging activity was 4.6× higher in leaf extract from ASE. No significant differences reported in ferric reducing power, and total flavonoid content of the leaf extract between the two methods. Cytotoxicity via MTT assay demonstrated no significant differences in cell viability upon exposure to the leaf extract from both methods. This suggested that they were appropriate in producing Durio zibethinus M. leaf extract for end use application in food related product. Both ensured similar level of safety in Durio zibethinus M. leaf extract as a new potential ingredient for the food industry.
    Matched MeSH terms: Free Radical Scavengers/analysis
  10. Fulltext Optimization of Flavonoid Extraction from Red and Brown Rice Bran and Evaluation of the Antioxidant Properties
    Ghasemzadeh A, Baghdadi A, Z E Jaafar H, Swamy MK, Megat Wahab PE
    Molecules, 2018 Jul 26;23(8).
    PMID: 30049990 DOI: 10.3390/molecules23081863
    Recently, the quality-by-design concept has been widely implemented in the optimization of pharmaceutical processes to improve batch-to-batch consistency. As flavonoid compounds in pigmented rice bran may provide natural antioxidants, extraction of flavonoid components from red and brown rice bran was optimized using central composite design (CCD) and response surface methodology (RSM). Among the solvents tested, ethanol was most efficient for extracting flavonoids from rice bran. The examined parameters were temperature, solvent percentage, extraction time, and solvent-to-solid ratio. The highest total flavonoid content (TFC) in red rice bran was predicted as 958.14 mg quercetin equivalents (QE)/100 g dry matter (DM) at 58.5 °C, 71.5% (v/v), 36.2 min, and 7.94 mL/g, respectively, whereas the highest TFC in brown rice bran was predicted as 782.52 mg QE/100 g DM at 56.7 °C, 74.4% (v/v), 36.9 min, and 7.18 mL/g, respectively. Verification experiment results under these optimized conditions showed that the TFC values for red and brown rice bran were 962.38 and 788.21 mg QE/100 g DM, respectively. No significant differences were observed between the predicted and experimental TFC values, indicating that the developed models are accurate. Analysis of the extracts showed that apigenin and p-coumaric acid are abundant in red and brown rice bran. Further, red rice bran with its higher flavonoid content exhibited higher nitric oxide and 2,2-diphenyl-1-picrylhydrazyl scavenging activities (EC50 values of 41.3 and 33.6 μg/mL, respectively) than brown rice bran. In this study, an extraction process for flavonoid compounds from red and brown rice bran was successfully optimized. The accuracy of the developed models indicated that the approach is applicable to larger-scale extraction processes.
    Matched MeSH terms: Free Radical Scavengers/pharmacology; Free Radical Scavengers/chemistry
  11. Fulltext Rational Design and Synthesis of New, High Efficiency, Multipotent Schiff Base-1,2,4-triazole Antioxidants Bearing Butylated Hydroxytoluene Moieties
    Yehye WA, Abdul Rahman N, Saad O, Ariffin A, Abd Hamid SB, Alhadi AA, et al.
    Molecules, 2016 Jun 28;21(7).
    PMID: 27367658 DOI: 10.3390/molecules21070847
    A new series of multipotent antioxidants (MPAOs), namely Schiff base-1,2,4-triazoles attached to the oxygen-derived free radical scavenging moiety butylated hydroxytoluene (BHT) were designed and subsequently synthesized. The structure-activity relationship (SAR) of the designed antioxidants was established alongside the prediction of activity spectra for substances (PASS). The antioxidant activities of the synthesized compounds 4-10 were tested by the DPPH bioassay. The synthesized compounds 4-10 inhibited stable DPPH free radicals at a level that is 10(-4) M more than the well-known standard antioxidant BHT. Compounds 8-10 with para-substituents were less active than compounds 4 and 5 with trimethoxy substituents compared to those with a second BHT moiety (compounds 6 and 7). With an IC50 of 46.13 ± 0.31 µM, compound 6 exhibited the most promising in vitro inhibition at 89%. Therefore, novel MPAOs containing active triazole rings, thioethers, Schiff bases, and BHT moieties are suggested as potential antioxidants for inhibiting oxidative stress processes and scavenging free radicals, hence, this combination of functions is anticipated to play a vital role in repairing cellular damage, preventing various human diseases and in medical therapeutic applications.
    Matched MeSH terms: Free Radical Scavengers/pharmacology; Free Radical Scavengers/chemistry
  12. Standardized extract of Syzygium aqueum: a safe cosmetic ingredient
    Palanisamy UD, Ling LT, Manaharan T, Sivapalan V, Subramaniam T, Helme MH, et al.
    Int J Cosmet Sci, 2011 Jun;33(3):269-75.
    PMID: 21284663 DOI: 10.1111/j.1468-2494.2010.00637.x
    Syzygium aqueum, a species in the Myrtaceae family, commonly called the water jambu is native to Malaysia and Indonesia. It is well documented as a medicinal plant, and various parts of the tree have been used in traditional medicine, for instance as an antibiotic. In this study, we show S. aqueum leaf extracts to have a significant composition of phenolic compounds, protective activity against free radicals as well as low pro-oxidant capability. Its ethanolic extract, in particular, is characterized by its excellent radical scavenging activity of EC(50) of 133 μg mL(-1) 1,1-diphenyl-2-picryl-hydrazyl (DPPH), 65 μg mL(-1) 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) and 71 μg mL(-1) (Galvinoxyl), low pro-oxidant capabilities and a phenolic content of 585-670 mg GAE g(-1) extract. The extract also displayed other activities, deeming it an ideal cosmetic ingredient. A substantial tyrosinase inhibition activity with an IC(50) of about 60 μg mL(-1) was observed. In addition, the extract was also found to have anti-cellulite activity tested for its ability to cause 98% activation of lipolysis of adipocytes (fat cells) at a concentration of 25 μg mL(-1). In addition, the extract was not cytotoxic to Vero cell lines up to a concentration of 600 μg mL(-1). Although various parts of this plant have been used in traditional medicine, this is the first time it has been shown to have cosmeceutical properties. Therefore, the use of this extract, alone or in combination with other active principles, is of interest to the cosmetic industry.
    Matched MeSH terms: Free Radical Scavengers/isolation & purification*; Free Radical Scavengers/pharmacology
  13. Hydrodynamic cavitation assisted degradation of persistent endocrine-disrupting organochlorine pesticide Dicofol: Optimization of operating parameters and investigations on the mechanism of intensification
    Panda D, Manickam S
    Ultrason Sonochem, 2019 Mar;51:526-532.
    PMID: 30224289 DOI: 10.1016/j.ultsonch.2018.04.003
    Dicofol, a recommended Stockholm convention persistent organic pollutants (POPs) candidate is well known for its endocrine disruptive properties and has been extensively used as an organochlorine pesticide worldwide. The hydrodynamic cavitation (HC) treatment of Dicofol in aqueous media induced by a liquid whistle hydrodynamic cavitaion reactor (LWHCR) has been investigated while considering important parameters such as inlet pressure, initial concentration of Dicofol, solution temperature, pH, addition of H2O2 and radical scavenger for the extent of degradation. The pseudo-first-order degradation rate constant (k) was determined to be 0.073 min-1 with a cavitational yield of 1.26 × 10-5 mg/J at optimum operating conditions and a complete removal of Dicofol was achieved within 1 h of treatment. Considering the removal rate and energy efficiency, the optimal inlet pressure was found to be 7 bar, resulting in a cavitation number of 0.17. High performance liquid chromatography (HPLC) and Gas chromatography mass spectroscopy (GC-MS) analyses indicated a sharp decline in the concentration of Dicofol with treatment time and indicated the presence of degraded products. An 85% total organic carbon (TOC) removal was achieved within 1 h of treatment time, demonstrating successful mineralization of Dicofol. The obtained results suggest that the degradation of Dicofol followed thermal decomposition and successive recombination reactions at bubble-vapor interface. Overall, the attempted hydrodynamic cavitation demonstrated successful and rapid removal of endocrine disruptive chemicals such as Dicofol and is expected to provide efficient solution for wastewater treatment.
    Matched MeSH terms: Free Radical Scavengers/chemistry
  14. In vitro anti-oxidant and anti-cancer activity of methanolic extract from Sanchezia speciosa leaves
    Paydar M, Wong YL, Moharam BA, Wong WF, Looi CY
    Pak J Biol Sci, 2013 Oct 15;16(20):1212-5.
    PMID: 24506026
    Sanchezia speciosa, is a bushy shrub from Acanthaceae family which commonly grows in tropical areas of South and Central America. In this study, we employed MTT assay to test the cytotoxicity of that methanolic fraction of S. speciosa leaves on MCF-7 human breast cancer, SK-MEL-5 human malignant melanoma and human umbilical vein endothelial cells, HUVEC cells. The extract showed highest activity on MCF-7 and moderate cytotoxicity towards SK-MEL-5. In contrast, the extract demonstrated lowest cell growth inhibition activity on HUVEC cells, indicating better selectivity compare to standard drug, doxorubicin. In addition, we also performed ORAC assay to determine the radical scavenging capacity of methanolic extract of S. speciosa leaves. The extract exhibited nearly similar anti-oxidant activity as quercetin, suggesting S. speciosa leaves as a potential source of natural anti-oxidant. To the best of our knowledge, this is the first report on anti-oxidant and cytotoxic activity of S. speciosa.
    Matched MeSH terms: Free Radical Scavengers/pharmacology; Free Radical Scavengers/chemistry
  15. Fulltext Antioxidant Potential of Red Palm-Pressed Mesocarp Olein
    Teh SS, Mah SH, Lau HLN, Teng KT, Loganathan R
    J Oleo Sci, 2021 Dec 03;70(12):1719-1729.
    PMID: 34759109 DOI: 10.5650/jos.ess21147
    Oxidative stress occurs due to the imbalance amount of the free radicals and antioxidants in human body which often associated with numerous chronic diseases. The antioxidant properties of red palm-pressed mesocarp olein (PPMO) have not been widely studied. Therefore, antioxidant properties of PPMO relative to commercially available edible oils, namely red palm olein (RPO), palm olein (PO), extra virgin olive oil (OO) and extra virgin coconut oil (CNO) were studied. PPMO exhibited significant higher phytonutrients which more than 2-fold compared to the edible oils. Overall, antioxidant screening indicated that PPMO has significantly higher antioxidant activities than RPO, PO and CNO in term of DPPH, H2O2, NO scavenging and FIC; and significantly higher H2O2 and FIC than OO. The outcomes of this study reveal that PPMO is as good as commercially available edible oil, also a good source for food applications and dietary nutritional supplements. More importantly, the utilization of PPMO could mitigate oil palm waste problem and results in positive environmental impact.
    Matched MeSH terms: Free Radical Scavengers
  16. Critical analysis of current methods for assessing the in vitro antioxidant and antibacterial activity of plant extracts
    Tan JB, Lim YY
    Food Chem, 2015 Apr 1;172:814-22.
    PMID: 25442625 DOI: 10.1016/j.foodchem.2014.09.141
    Natural product research is an active branch of science, driven by the increased value placed on individual health and well-being. Many naturally-occurring phytochemicals in plants, fruits and vegetables have been reported to exhibit antioxidant and antibacterial activity; often touted as being beneficial for human health. In vitro screening is a common practice in many research laboratories as a means of rapidly assessing these properties. However, the methods used by many are not necessarily optimal; a result of poor standardization, redundant assays and/or outdated methodology. This review primarily aims to give a better understanding in the selection of in vitro assays, with emphasis placed on some common assays such as the total phenolic content assay, free radical scavenging activity, disc-diffusion and broth microdilution. This includes a discussion on the reasons for choosing a particular assay, its strengths and weaknesses, ways to improve the accuracy of results and alternative assays.
    Matched MeSH terms: Free Radical Scavengers/pharmacology
  17. Fulltext A Kinetic Approach of DPPH Free Radical Assay of Ferulate-Based Protic Ionic Liquids (PILs)
    Ahmad NA, Jumbri K, Ramli A, Abd Ghani N, Ahmad H, Lim JW
    Molecules, 2018 Dec 05;23(12).
    PMID: 30563037 DOI: 10.3390/molecules23123201
    The antiradical efficiency (AE) and kinetic behavior of a new ferulate-based protic ionic liquids (PILs) were described using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical assay. The reduction of the DPPH free radical (DPPH•) was investigated by measuring the decrease in absorbance at 517 nm. The time to reach steady state for the reaction of parent acid (ferulic acid) and synthesized PILs with DPPH• was continuously recorded for 1 h. Results revealed that the AE of 2-butylaminoethanol ferulate (2BAEF), 3-dimethylaminopropanol ferulate (3DMAPF) and 3-diethylaminopropanol ferulate (3DEAPF) PILs have improved compared to ferulic acid (FA) as the reaction class changes from low to medium. This attributed to the strong hydrogen abstraction occurred in the PILs. Furthermore, these PILs were found to have a good kinetic behavior compared to FA due to the high rate constant (k₂) (164.17, 242.84 and 244.73 M-1 s-1, respectively). The alkyl chain length and more alkyl substituents on the nitrogen atom of cation were believed to reduce the cation-anion interaction and speed up the hydrogen atom transfer (HAT) and electron transfer (ET) mechanisms; hence, increased rate constant was observed leading to a strong antioxidant activity of the synthesized PILs.
    Matched MeSH terms: Free Radical Scavengers/pharmacology; Free Radical Scavengers/chemistry*
  18. Evaluation of biological activities of Alpinia mutica Roxb. and its chemical constituents
    Mustahil NA, Sukari MA, Abdul AB, Ali NA, Lian GE
    Pak J Pharm Sci, 2013 Mar;26(2):391-5.
    PMID: 23455212
    Phytochemicals investigation on rhizomes of Alpinia mutica has afforded five compounds namely 5,6-dehydrokawain (1), flavokawin B (2), pinostrobin (3) and pinocembrin (4) together with β-sitosterol (5). All crude extracts of the plant demonstrated strong cytotoxicity against CEMss (human T4 lymphoblastoid) cancer cells with IC50 values less than 19 μg/mL, while flavokawin B (2) was the most cytotoxic isolate with IC50 value 1.86±0.37 μg/mL. Most of the crude extracts and isolated compounds showed weak activity in antimicrobial and diphenylpicrylhydrazyl (DPPH) radical scavenging activity tests.
    Matched MeSH terms: Free Radical Scavengers/pharmacology
  19. Fulltext Antioxidant and Antidiabetic Effects of Flavonoids: A Structure-Activity Relationship Based Study
    Sarian MN, Ahmed QU, Mat So'ad SZ, Alhassan AM, Murugesu S, Perumal V, et al.
    Biomed Res Int, 2017;2017:8386065.
    PMID: 29318154 DOI: 10.1155/2017/8386065
    The best described pharmacological property of flavonoids is their capacity to act as potent antioxidant that has been reported to play an important role in the alleviation of diabetes mellitus. Flavonoids biochemical properties are structure dependent; however, they are yet to be thoroughly understood. Hence, the main aim of this work was to investigate the antioxidant and antidiabetic properties of some structurally related flavonoids to identify key positions responsible, their correlation, and the effect of methylation and acetylation on the same properties. Antioxidant potential was evaluated through dot blot, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, ABTS+ radical scavenging, ferric reducing antioxidant power (FRAP), and xanthine oxidase inhibitory (XOI) assays. Antidiabetic effect was investigated through α-glucosidase and dipeptidyl peptidase-4 (DPP-4) assays. Results showed that the total number and the configuration of hydroxyl groups played an important role in regulating antioxidant and antidiabetic properties in scavenging DPPH radical, ABTS+ radical, and FRAP assays and improved both α-glucosidase and DPP-4 activities. Presence of C-2-C-3 double bond and C-4 ketonic group are two essential structural features in the bioactivity of flavonoids especially for antidiabetic property. Methylation and acetylation of hydroxyl groups were found to diminish the in vitro antioxidant and antidiabetic properties of the flavonoids.
    Matched MeSH terms: Free Radical Scavengers/chemistry*
  20. Fulltext The sensitivity of the DNA damage checkpoint prevents oocyte maturation in endometriosis
    Hamdan M, Jones KT, Cheong Y, Lane SI
    Sci Rep, 2016 11 14;6:36994.
    PMID: 27841311 DOI: 10.1038/srep36994
    Mouse oocytes respond to DNA damage by arresting in meiosis I through activity of the Spindle Assembly Checkpoint (SAC) and DNA Damage Response (DDR) pathways. It is currently not known if DNA damage is the primary trigger for arrest, or if the pathway is sensitive to levels of DNA damage experienced physiologically. Here, using follicular fluid from patients with the disease endometriosis, which affects 10% of women and is associated with reduced fertility, we find raised levels of Reactive Oxygen Species (ROS), which generate DNA damage and turn on the DDR-SAC pathway. Only follicular fluid from patients with endometriosis, and not controls, produced ROS and damaged DNA in the oocyte. This activated ATM kinase, leading to SAC mediated metaphase I arrest. Completion of meiosis I could be restored by ROS scavengers, showing this is the primary trigger for arrest and offering a novel clinical therapeutic treatment. This study establishes a clinical relevance to the DDR induced SAC in oocytes. It helps explain how oocytes respond to a highly prevalent human disease and the reduced fertility associated with endometriosis.
    Matched MeSH terms: Free Radical Scavengers/pharmacology
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