Displaying publications 21 - 40 of 77 in total

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  1. Antioxidant and gastroprotective activities of Andrographis paniculata (Hempedu Bumi) in Sprague Dawley rats
    Wasman SQ, Mahmood AA, Chua LS, Alshawsh MA, Hamdan S
    Indian J Exp Biol, 2011 Oct;49(10):767-72.
    PMID: 22013743
    Antioxidant and gastroprotective activities of aqueous and ethanolic extract of Andrographis paniculata leaves in rats have been reported. Sprague Dawley rats, 6 per group were used and rats in groups 1 to 6 were pretreated with (0.25% w/v) carboxymethyl cellulose (negative control, 5 ml/kg), 20 mg/kg omeprazole (positive control), (250 mg/kg and 500 mg/kg) of aqueous leaf extracts (APLAE) and (250 and 500 mg/kg) of ethanol leaf extracts (APLEE) respectively. Animals were orally administered with 95% ethanol (5 ml/kg) 60 min after their pretreatments. Rats were sacrificed 1 h after treatment and gastric contents were collected to measure pH and mucous weight. Stomach was analyzed for gross and histological changes. Ulcer control group showed extensive lesions of gastric mucosal layer, whereas rats pretreated with omeprazole, 250 and 500 mg/kg of APLAE showed significant and dose dependent reduction in gastric lesions with increased pH and mucus content of stomach. Rats pretreated with 250 or 500 mg/kg of APLEE showed significantly better inhibition of gastric mucosal lesions. Further, the in vitro antioxidant studies using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay showed that ethanol extracts have superior free radical scavenging activity with IC50 value = 10.9 than aqueous extracts with IC50 value = 24.65. Results of this study showed that pretreatment with ethonolic extract of A. paniculata ethanolic provided significant protection against gastric ulcer by regulating of pH, mucous production and antioxidant property.
    Matched MeSH terms: Free Radical Scavengers/pharmacology
  2. Fulltext In vitro antioxidant and in vivo antidepressant activity of green synthesized azomethine derivatives of cinnamaldehyde
    Chigurupati S, Shaikh SA, Mohammad JI, Selvarajan KK, Nemala AR, Khaw CH, et al.
    Indian J Pharmacol, 2017 10 17;49(3):229-235.
    PMID: 29033482 DOI: 10.4103/ijp.IJP_293_16
    OBJECTIVES: In this study, three (CS-1 to CS-3) azomethine derivatives of cinnamaldehyde were green synthesized, characterized, and their antioxidant and antidepressant activities were explored.

    MATERIALS AND METHODS: The antioxidant effect of these compounds was initially performed in vitro using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay methods before subjecting them to in vivo experiments. Compounds showing potent antioxidant activity (CS-1 and CS-2) were investigated further for their antidepressant activity using the forced swim test (FST) and tail suspension test (TST). Ascorbic acid (AA) and fluoxetine (20 mg/kg, p.o) were used as reference drugs for comparison in the antioxidant and antidepressant experiments, respectively.

    RESULTS: It was observed that CS-2 and CS-3 exhibited highest DPPH (half maximal inhibitory concentration [IC50]: 16.22 and 25.18 μg/mL) and ABTS (IC50: 17.2 and 28.86 μg/mL) radical scavenging activity, respectively, compared to AA (IC50: 15.73 and 16.79 μg/mL) and therefore, both CS-2 and CS-3 were tested for their antidepressant effect using FST and TST as experimental models. Pretreatment of CS-2 and CS-3 (20 mg/kg) for 10 days considerably decreased the immobility time in both the FST and TST models.

    CONCLUSION: The antioxidant and antidepressant effect of CS-2 and CS-3 may be attributed to the presence of azomethine linkage in the molecule.

    Matched MeSH terms: Free Radical Scavengers/pharmacology
  3. Cytotoxic effect of fucoidan extracted from Sargassum cinereum on colon cancer cell line HCT-15
    Somasundaram SN, Shanmugam S, Subramanian B, Jaganathan R
    Int J Biol Macromol, 2016 Oct;91:1215-23.
    PMID: 27370748 DOI: 10.1016/j.ijbiomac.2016.06.084
    The present study was aimed to investigate the antioxidant and cytotoxicity activity against HCT-15 of fucoidan from Sargassum cinereum. Purification of fucoidan was done by DEAE cellulose and dialysis. Physicochemical characterization of fucoidan was analysed by calorimetric assay, FT-IR, HPLC and NMR. The extracted fucoidan contains 65.753% of fucose and 3.7±1.54% of sulphate respectively. HPLC results showed that the fucoidan contains the monosaccharide composition such as fucose, galactose, mannose and xylose. Antioxidant effect of fucoidan in Sargassum Cinereum was determined by DPPH. The maximum DPPH activity was found at the concentration of 100μg, where as the crude extract showed the scavenging activity was 63.58±0.56%. Cytotoxicity effect was done by MTT assay. Fucoidan extract caused about 50% of cell death after 24h of incubation with 75±0.9037μg/ml against HCT-15.
    Matched MeSH terms: Free Radical Scavengers/pharmacology*
  4. 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/pharmacology
  5. Comparative study of antioxidant activities and total phenolic content of selected edible wild mushrooms
    Yim HS, Chye FY, Lee MY, Matanjun P, How SE, Ho CW
    Int J Med Mushrooms, 2011;13(3):245-55.
    PMID: 22135876
    The present study aims to assess the antioxidant activities (AOA) and total phenolic content (TPC) of water extracts of selected edible wild mushrooms: Pleurotus porrigens, Schizophyllum commune, Hygrocybe conica, and Lentinus ciliatus. The AOA were evaluated against DPPH radical and ABTS radical cation scavenging ability, ferric-reducing antioxidant power (FRAP) and beta-carotene-linoleate bleaching (beta-CB) assays, and the Folin-Ciocalteu method for TPC. BHA was used as reference. P. porrigens showed significantly higher (p < 0.05) DPPH* scavenging ability (90.78 +/- 0.30%) and FRAP (6.37 +/- 0.22 mM FE/100g), while Sch. commune showed significantly higher (p < 0.05) ABTS*+ inhibition activity (94.96 +/- 0.70%) and beta-CB inhibition activity (94.18 +/- 0.17%), respectively. TPC was found in a descending order of P. poriggens > L. ciliatus = Pleurotus ostreatus (cultivated) > H. conica = Sch. commune. Positive correlation was observed between the AOA and TPC. When compared to BHA (2 mM), P. porrigens showed significantly higher (p < 0.05) DPPH* scavenging ability and reducing power, while Sch. commune showed comparable DPPH* scavenging ability and ABTS*+ inhibition activity. All the mushrooms have better ABTS*+ inhibition activity than BHA (1 mM). The beta-CB inhibition activity of BHA was significantly higher than those of edible wild mushrooms. The water extracts of edible wild mushrooms showed potent antioxidant activities compared to BHA to a certain extent.
    Matched MeSH terms: Free Radical Scavengers/pharmacology*
  6. Fulltext Gelam honey scavenges peroxynitrite during the immune response
    Kassim M, Mansor M, Suhaimi A, Ong G, Yusoff KM
    Int J Mol Sci, 2012;13(9):12113-29.
    PMID: 23109904 DOI: 10.3390/ijms130912113
    Monocytes and macrophages are part of the first-line defense against bacterial, fungal, and viral infections during host immune responses; they express high levels of proinflammatory cytokines and cytotoxic molecules, including nitric oxide, reactive oxygen species, and their reaction product peroxynitrite. Peroxynitrite is a short-lived oxidant and a potent inducer of cell death. Honey, in addition to its well-known sweetening properties, is a natural antioxidant that has been used since ancient times in traditional medicine. We examined the ability of Gelam honey, derived from the Gelam tree (Melaleuca spp.), to scavenge peroxynitrite during immune responses mounted in the murine macrophage cell line RAW 264.7 when stimulated with lipopolysaccharide/interferon-γ (LPS/IFN-γ) and in LPS-treated rats. Gelam honey significantly improved the viability of LPS/IFN-γ-treated RAW 264.7 cells and inhibited nitric oxide production-similar to the effects observed with an inhibitor of inducible nitric oxide synthase (1400W). Furthermore, honey, but not 1400W, inhibited peroxynitrite production from the synthetic substrate 3-morpholinosydnonimine (SIN-1) and prevented the peroxynitrite-mediated conversion of dihydrorhodamine 123 to its fluorescent oxidation product rhodamine 123. Honey inhibited peroxynitrite synthesis in LPS-treated rats. Thus, honey may attenuate inflammatory responses that lead to cell damage and death, suggesting its therapeutic uses for several inflammatory disorders.
    Matched MeSH terms: Free Radical Scavengers/pharmacology*
  7. 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/pharmacology
  8. Two new xanthones from Artocarpus obtusus
    Hashim N, Rahmani M, Sukari MA, Ali AM, Alitheen NB, Go R, et al.
    J Asian Nat Prod Res, 2010 Feb;12(2):106-12.
    PMID: 20390751 DOI: 10.1080/10286020903450411
    Two new xanthones, pyranocycloartobiloxanthone A (1) and dihydroartoindonesianin C (2), were isolated from the stem bark of Artocarpus obtusus Jarrett by chromatographic separation. Their structures were determined by using spectroscopic methods and comparison with known related compounds. Pyranocycloartobiloxanthone A (1) showed strong free radical scavenging activity by using DPPH assay as well as cytotoxicity towards K562, HL-60, and MCF7 cell lines.
    Matched MeSH terms: Free Radical Scavengers/pharmacology
  9. Antioxidant compounds from the stem bark of Garcinia atroviridis
    Tan WN, Khairuddean M, Wong KC, Tong WY, Ibrahim D
    J Asian Nat Prod Res, 2016 Aug;18(8):804-11.
    PMID: 26999039 DOI: 10.1080/10286020.2016.1160071
    A new xanthone, namely garcinexanthone G (1), along with eight known compounds, stigmasta-5,22-dien-3β-ol (2), stigmasta-5,22-dien-3-O-β-glucopyranoside (3), 3β-acetoxy-11α,12α-epoxyoleanan-28,13β-olide (4), 2,6-dimethoxy-p-benzoquinone (5), 1,3,5-trihydroxy-2-methoxyxanthone (6), 1,3,7-trihydroxyxanthone (7), kaempferol (8) and quercetin (9), were isolated from the stem bark of Garcinia atroviridis. Their structures were elucidated based on spectroscopic methods including nuclear magnetic resonance (NMR-1D and 2D), UV, IR, and mass spectrometry. All the isolated compounds were evaluated for their antioxidant properties based on the DPPH radical scavenging activities. Results showed that 1,3,7-trihydroxyxanthone and quercetin showed significant antioxidant activities with EC50 values of 16.20 and 12.68 μg/ml, respectively, as compared to the control, ascorbic acid (7.4 μg/ml).
    Matched MeSH terms: Free Radical Scavengers/pharmacology*
  10. Identification and quantification of phenolic compounds in bambangan (Mangifera pajang Kort.) peels and their free radical scavenging activity
    Hassan FA, Ismail A, Abdulhamid A, Azlan A
    J Agric Food Chem, 2011 Sep 14;59(17):9102-11.
    PMID: 21800901 DOI: 10.1021/jf201270n
    Phenolic compounds and antioxidant capacity of acidified methanolic extract prepared from fully ripe bambangan (Mangifera pajang K.) peel cultivated in Sarawak, Malaysia, were analyzed. The total phenolic content (98.3 mg GAE/g) of bambangan peel powder (BPP) was determined by the Folin-Ciocalteu method. BPP showed a strong potency of antioxidant activity and was consistent with that of BHT and vitamin C as confirmed by the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity and FRAP (ferric-reducing antioxidant power) assays. Gallic acid, p-coumaric acid, ellagic acid, protocatechuic acid, and mangiferin were the major compounds among the 16 phenolics that have been identified and quantified in M. pajang peels with 20.9, 12.7, 7.3, 5.4, and 4.8 mg/g BPP, respectively. Peak identities were confirmed by comparing their retention times, UV-vis absorption spectra, and mass spectra with authentic standards. The 16 phenolic compounds identified in M. pajang K. using HPLC-DAD and TSQ-ESI-MS are reported here for the first time.
    Matched MeSH terms: Free Radical Scavengers/pharmacology*
  11. Isolation and identification of radical scavenging and tyrosinase inhibition of polyphenols from Tibouchina semidecandra L
    Sirat HM, Rezali MF, Ujang Z
    J Agric Food Chem, 2010 Oct 13;58(19):10404-9.
    PMID: 20809630 DOI: 10.1021/jf102231h
    Phytochemical and bioactivity studies of the leaves and stem barks of Tibouchina semidecandra L. have been carried out. The ethyl acetate extract of the leaves yielded four flavonoid compounds, identified as quercetin, quercetin 3-O-α-l-(2''-O-acetyl) arabinofuranoside, avicularin, and quercitrin, while the stem barks gave one ellagitannin, identified as 3,3'-O-dimethyl ellagic acid 4-O-α-l-rhamnopyranoside. Evaluation of the antioxidative activity on the crude extracts and pure compounds by electron spin resonance (ESR) and ultraviolet-visible (UV-vis) spectrophotometric assays showed that the pure isolated polyphenols and the EtOAc extract possessed strong antioxidative capabilities. Quercetin was found to be the most active radical scavenger in DPPH-UV and ESR methods with SC(50) values of 0.7 μM ± 1.4 and 0.7 μM ± 0.6 μM, respectively, in the antioxidant assay. A combination of quercetin and quercitrin was tested for synergistic antioxidative capacity;, however, there was no significant improvement observed. Quercetin also exhibited strong antityrosinase activity with a percent inhibition of 95.0% equivalent to the positive control, kojic acid, in the tyrosinase inhibition assay.
    Matched MeSH terms: Free Radical Scavengers/pharmacology*
  12. Evaluation of antioxidant and nitric oxide inhibitory activities of selected Malaysian medicinal plants
    Saha K, Lajis NH, Israf DA, Hamzah AS, Khozirah S, Khamis S, et al.
    J Ethnopharmacol, 2004 Jun;92(2-3):263-7.
    PMID: 15138010
    Methanol extracts of seven Malaysian medicinal plants were screened for antioxidant and nitric oxide inhibitory activities. Antioxidant activity was measured by using FTC, TBA and DPPH free radical scavenging methods and Griess assay was used for the measurement of nitric oxide inhibition in lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma)-treated RAW 264.7 cells. All the extracts showed strong antioxidant activity comparable to or higher than that of alpha-tocopherol, BHT and quercetin in FTC and TBA methods. The extracts from Leea indica and Spermacoce articularis showed strong DPPH free radical scavenging activity comparable with quercetin, BHT and Vit C. Spermacoce exilis showed only moderate activity but other species were weak as compared to the standards. In the Griess assay Lasianthus oblongus, Chasalia chartacea, Hedyotis verticillata, Spermacoce articularis and Leea indica showed strong inhibitory activity on nitric oxide production in LPS and IFN-gamma-induced RAW 264.7 cells. Extracts from Psychotria rostrata and Spermacoce exilis also inhibited NO production but this was due to their cytotoxic effects upon cells during culture.
    Matched MeSH terms: Free Radical Scavengers/pharmacology*
  13. Standardization of Kaempferia galanga L. rhizome and vasorelaxation effect of its key metabolite ethyl p-methoxycinnamate
    Srivastava N, Mishra S, Iqbal H, Chanda D, Shanker K
    J Ethnopharmacol, 2021 May 10;271:113911.
    PMID: 33571614 DOI: 10.1016/j.jep.2021.113911
    ETHNOPHARMACOLOGICAL RELEVANCE: Kaempferia galanga L. rhizome (KGR) is part of more than sixty-one Ayurvedic formulations and commonly known as 'Chandramula'. KGR is widely used in traditional Indian medicines to treat fever (jwar), rheumatism (Amavata), respiratory (Shwasa), hypertension (Vyanabala vaishamya) and cardiovascular disorders (Vyanavayu Dushtijanya Hrudrog). Although ethnomedicinal properties have extensively been demonstrated in traditional medicines of south-east countries i.e. China, India, Indonesia, and Malaysia, the chemico-biological validation are still lacking.

    AIM OF THE STUDY: Chemico-biological standardization with respect to its vasorelaxation potential is the main objective of the present study. To investigate the vasorelaxation potential of key phytochemical of KGR, i.e., ethyl-p-methoxycinnamate (EPMC) and to study it's the mechanism of action.

    MATERIALS AND METHODS: A HPLC method was developed and validated for the quality assessment of KGR using its two major phytochemicals i.e. ethyl-p-methoxycinnamate (EPMC) and ethyl cinnamate (EC) in KGR. The vasorelaxation effect of major phytochemicals of KGR was evaluated on the main mesenteric arteries isolated from male Wistar rats. Specific BKca channel blocker tetraethylammonium (TEA), receptor antagonist, nitric oxide scavenging capacity, and antioxidant potential were also evaluated for its plausible mechanism.

    RESULTS: Present validated HPLC method facilitates simultaneous quantitation of EPMC and EC faster than classical GC techniques. EPMC has shown a dose-dependent relaxation in rat main mesenteric arteries (MMA) contracted by U46619 with an Emax of 58.68 ± 3.31%. Similarly, in endothelium-denuded MMA rings, relaxation was also observed (Emax of 61.83 ± 3.38%). Moreover, relaxation response to EPMC has strongly inhibited (Emax 14.76 ± 2.29%) when the tissue exposed to depolarizing high K+ containing buffer for the contraction. The point correlation dimension (pD2) values were also significantly decreased in high K+ treated arterial rings compared to control. Interestingly, when MMA rings incubated with a specific BKca channel blocker (TEA, 1 mM), the relaxation response to EPMC was also significantly blocked.

    CONCLUSIONS: The first time this study demonstrated the chemical standardization of K. galanga rhizome and EPMC is responsible for its vasorelaxation potential as demonstrated by the endothelium-independent response mediated by Ca2+ dependent potassium channels.

    Matched MeSH terms: Free Radical Scavengers/pharmacology
  14. Synthesis of Fluorescent 1-(3-Amino-4-(4-(tert-butyl)phenyl)-6-(p-tolyl)furo[2,3-b]pyridin-2-yl)ethan-1-one: Crystal Structure, Fluorescence Behavior, Antimicrobial and Antioxidant Studies
    Ibrahim MM, Al-Refai M, Al-Fawwaz A, Ali BF, Geyer A, Harms K, et al.
    J Fluoresc, 2018 Mar;28(2):655-662.
    PMID: 29680927 DOI: 10.1007/s10895-018-2227-2
    Furopyridine III, namely 1-(3-amino-4-(4-(tert-butyl)phenyl)-6-(p-tolyl)furo[2,3-b]pyridin-2-yl)ethan-1-one, synthesized from 4-(4-(tert-butyl)phenyl)-2-oxo-6-(p-tolyl)-1,2-dihydropyridine-3-carbonitrile I in two steps. The title compound is characterized by NMR, MS and its X-ray structure. The molecular structure consists of planar furopyridine ring with both phenyl rings being inclined from the furopyridine scaffold to a significant different extent. There are three intramolecular hydrogen bonds within the structure. The lattice is stabilized by N-H…O, H2C-H …π and π…π intermolecular interactions leading to three-dimensional network. Compound III exhibits fluorescent properties, which are investigated. Antimicrobial potential and antioxidant activity screening studies for the title compound III and the heterocyclic derivatives, I and II, show no activity towards neither bacterial nor fungal strains, while they exhibited weak to moderate antioxidant activity compared to reference.
    Matched MeSH terms: Free Radical Scavengers/pharmacology
  15. Antioxidant capacity of fresh and processed fruit bodies and mycelium of Auricularia auricula-judae (Fr.) Quél
    Kho YS, Vikineswary S, Abdullah N, Kuppusamy UR, Oh HI
    J Med Food, 2009 Feb;12(1):167-74.
    PMID: 19298211 DOI: 10.1089/jmf.2007.0568
    Auricularia auricula-judae is currently grown in Malaysia. In the present study, the methanolic extracts from fruit bodies (fresh, oven-dried, and freeze-dried) and mycelium of A. auricula-judae were evaluated for their antioxidant capacities based on 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity and ferric reducing antioxidant power (FRAP) assay. The total phenolic content in the extracts were also measured. The extract of freeze-dried fruit bodies of A. auricula-judae had potent DPPH free radical scavenging activity with a 50% effective concentration of 2.87 mg/mL, whereas the FRAP value of A. auricula-judae mycelium was 5.22 micromol of FeSO(4).7H(2)O equivalents/g of mycelium sample. Further, a positive correlation (R(2) = 0.7668) between FRAP level of A. auricula-judae extracts and the total phenolic contents was observed. Thus the method of processing of fresh fruit bodies had an effect on the antioxidant potential of A. auricula-judae.
    Matched MeSH terms: Free Radical Scavengers/pharmacology*
  16. The antioxidant properties of garlic compounds: allyl cysteine, alliin, allicin, and allyl disulfide
    Chung LY
    J Med Food, 2006;9(2):205-13.
    PMID: 16822206
    Garlic and garlic extracts, through their antioxidant activities, have been reported to provide protection against free radical damage in the body. This study investigated antioxidant properties of garlic compounds representing the four main chemical classes, alliin, allyl cysteine, allyl disulfide, and allicin, prepared by chemical synthesis or purification. Alliin scavenged superoxide, while allyl cysteine and allyl disulfide did not react with superoxide. Allicin suppressed the formation of superoxide by the xanthine/xanthine oxidase system, probably via a thiol exchange mechanism. Alliin, allyl cysteine, and allyl disulfide all scavenged hydroxyl radicals; the rate constants calculated based on deoxyribose competitive assay were 1.4-1.7 x 10(10), 2.1-2.2 x 10(9), and 0.7-1.5 x 10(10) M (1) second(1), respectively. Contrary to previous reports, allicin did not exhibit hydroxyl radical scavenging activity in this study. Alliin, allicin, and allyl cysteine did not prevent induced microsomal lipid peroxidation, but both alliin and allyl cysteine were hydroxyl scavengers, and allyl disulfide was a lipid peroxidation terminator. In summary, our findings indicated that allyl disulfide, alliin, allicin, and allyl cysteine exhibit different patterns of antioxidant activities as protective compounds against free radical damage.
    Matched MeSH terms: Free Radical Scavengers/pharmacology
  17. A new prenylated dihydrochalcone from the leaves of Artocarpus lowii
    Jamil S, Sirat HM, Jantan I, Aimi N, Kitajima M
    J Nat Med, 2008 Jul;62(3):321-4.
    PMID: 18404311 DOI: 10.1007/s11418-008-0226-3
    A new prenylated dihydrochalcone, 2',4'-dihydroxy-4-methoxy-3'-prenyldihydrochalcone (1), along with two known compounds, 2',4',4-trihydroxy-3'-prenylchalcone (2) and 2',4-dihydroxy-3',4'-(2,2-dimethylchromene)chalcone (3) were isolated from the leaves of Artocarpus lowii. The structures of 1-3 were elucidated by spectroscopic methods and by comparison with data reported in the literature. Compounds 1-3 showed strong free radical scavenging activity towards 2,2-diphenyl-1-picrylhydrazyl (DPPH) measured by electron spin resonance (ESR) spectrometry.
    Matched MeSH terms: Free Radical Scavengers/pharmacology
  18. Antioxidant, radical-scavenging, anti-inflammatory, cytotoxic and antibacterial activities of methanolic extracts of some Hedyotis species
    Ahmad R, Ali AM, Israf DA, Ismail NH, Shaari K, Lajis NH
    Life Sci, 2005 Mar 11;76(17):1953-64.
    PMID: 15707878
    The antioxidant, radical-scavenging, anti-inflammatory, cytotoxic and antibacterial activities of methanolic extracts of seven Hedyotisspecies were investigated. The antioxidant activity was evaluated by the ferric thiocyanate (FTC) and thiobarbituric acid (TBA) methods while the radical scavenging activity was measured by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method. The anti-inflammatory activity related to NO inhibition of the plant extracts was measured by the Griess assay while cytotoxicity were measured by the MTT assay against CEM-SS cell line. The antibacterial bioassay (against 4 bacteria, i.e. Bacillus subtilis B28 (mutant), Bacillus subtilis B29 (wild-type), Pseudomonas aeruginosa UI 60690 and methicillin resistant Staphylococcus aureus, (MRSA) was also carried out using the disc-diffusion method. All tested extracts exhibited very strong antioxidant properties when compared to Vitamin E (alpha-tocopherol) with percent inhibition of 89-98% in the FTC and 60-95% in the TBA assays. In the DPPH method, H. herbacea exhibited the strongest radical scavenging activity with an IC50 value of 32 microg/ml. The results from the Griess assay showed that the tested extracts are weak inhibitors of NO synthase. However, all tested extracts exhibited moderate cytotoxic properties against CEM-SS cell line giving CD50 values in the range of 21-41 microg/ml. In the antibacterial bioassay, the stems and the roots of H. capitellata showed moderate activity against the 4 tested bacteria while the leaves showed moderate activity towards B. subtilis B28, MRSA and P. aeruginosa only. The roots of H. dichotoma showed strong antibacterial activity against all 4 bacteria. All other extracts did not exhibit any antibacterial activity.
    Matched MeSH terms: Free Radical Scavengers/pharmacology*
  19. Radical scavenging activity of lipophilized products from transesterification of flaxseed oil with cinnamic acid or ferulic acid
    Choo WS, Birch EJ, Stewart I
    Lipids, 2009 Sep;44(9):807-15.
    PMID: 19727883 DOI: 10.1007/s11745-009-3334-2
    Lipase-catalyzed transesterification of flaxseed oil with cinnamic acid (CA) or ferulic acid (FA) using an immobilized lipase from Candida antarctica (E.C. 3.1.1.3) was conducted to evaluate whether the lipophilized products provided enhanced antioxidant activity in the oil. Lipase-catalyzed transesterification of flaxseed oil with CA or FA produced a variety of lipophilized products (identified using ESI-MS-MS) such as monocinnamoyl/feruloyl-diacylglycerol, dicinnamoyl-monoacylglycerol and monocinnamoyl-monoacylglycerol. The free radical scavenging activity of the lipophilized products of lipase-catalyzed transesterification of flaxseed oil with CA or FA toward 2,2-diphenyl-1-picrylhydrazyl radical (DPPH.) were both examined in ethanol and ethyl acetate. The polarity of the solvents proved important in determining the radical scavenging activity of the substrates. Unesterified FA showed the highest free radical scavenging activity among all substrates tested while CA had negligible activity. The esterification of CA or FA with flaxseed oil resulted in significant increase and decrease in the radical scavenging activity compared with the native phenolic acid, respectively. Based on the ratio of a substrate to DPPH. concentration, lipophilized FA was a much more efficient free radical scavenger compared to lipophilized CA and was able to provide enhanced antioxidant activity in the flaxseed oil. Lipophilized cinnamic acid did not provide enhanced radical scavenging activity in the flaxseed oil as the presence of natural hydrophilic antioxidants in the oil had much greater radical scavenging activity.
    Matched MeSH terms: Free Radical Scavengers/pharmacology*
  20. Fulltext Volatile profiling of aromatic traditional medicinal plant, Polygonum minus in different tissues and its biological activities
    Ahmad R, Baharum SN, Bunawan H, Lee M, Mohd Noor N, Rohani ER, et al.
    Molecules, 2014 Nov 20;19(11):19220-42.
    PMID: 25420073 DOI: 10.3390/molecules191119220
    The aim of this research was to identify the volatile metabolites produced in different organs (leaves, stem and roots) of Polygonum minus, an important essential oil producing crop in Malaysia. Two methods of extraction have been applied: Solid Phase Microextraction (SPME) and hydrodistillation coupled with Gas Chromatography-Mass Spectrometry (GC-MS). Approximately, 77 metabolites have been identified and aliphatic compounds contribute significantly towards the aroma and flavour of this plant. Two main aliphatic compounds: decanal and dodecanal were found to be the major contributor. Terpenoid metabolites were identified abundantly in leaves but not in the stem and root of this plant. Further studies on antioxidant, total phenolic content, anticholinesterase and antimicrobial activities were determined in the essential oil and five different extracts. The plant showed the highest DPPH radical scavenging activity in polar (ethanol) extract for all the tissues tested. For anti-acetylcholinesterase activity, leaf in aqueous extract and methanol extract showed the best acetylcholinesterase inhibitory activities. However, in microbial activity, the non-polar extracts (n-hexane) showed high antimicrobial activity against Methicillin-resistant Staphylococcus aureus (MRSA) compared to polar extracts. This study could provide the first step in the phytochemical profiles of volatile compounds and explore the additional value of pharmacology properties of this essential oil producing crop Polygonum minus.
    Matched MeSH terms: Free Radical Scavengers/pharmacology
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