Katalitička oksidacija i antioksidacijska svojstva eteričnih ulja timijana (Thymus vulgaris L.)

The antioxidant properties of two chemotypes of thyme essential oils were examined in relation to their catalytic transformation. Catalytic oxidations were performed with potassium hydrogentrioxoperoxosulfate(VI) and the FeIII meso-tetraphenylporphyrin catalytic system, after which the chemical compositions of essential oils were changed. The antioxidant activity was investigated by two different methods: the 2,2\u27-diphenyl-1-picrylhydrazyl radical scavenging method and the Ferric Reducing / Antioxidant Power assay. Both methods have shown that the phenolic chemotype possesses stronger antioxidant properties than the non-phenolic one. After catalytic oxidation, the essential oils of both chemotypes showed stronger antioxidant effects than before oxidation.Ispitana su antioksidacijska svojstva eteričnih ulja dvaju kemotipova timijana ovisno o njihovoj katalitičkoj transformaciji. Katalitička transformacija je provedena s kalijevim hidrogentrioksoperoksosulfatom(VI) i FeIII mezo-tetrafenilporfirin katalitičkim sustavom, poslije čega je kemijski sastav eteričnih ulja izmijenjen. Antioksidacijska aktivnost ispitana je s dvije različite metode (2,2\u27-diphenyl-1-picrylhydrazyl radical scavenging i Ferric Reducing / Antioxidant Power). Obje su metode pokazale da fenolni kemotip posjeduje jača antioksidacijska svojstva od nefenolnoga tipa. Poslije katalitičke oksidacije, eterična ulja obaju kemotipova timijana pokazivala su jači antioksidacijski učinak

Chemical Composition and Antioxidant Effect of Free Volatile Aglycones from Nutmeg (Myristica fragrans Houtt.) Compared to Its Essential Oil

The paper reports on the isolation of glycosidically bound volatiles from nutmeg, identification of free aglycones, and determination of the antioxidative power of free aglycones in comparison with nutmeg essential oil. Comparison of the chemical composition of free volatiles with the chemical composition of free volatile compounds found in the essential oil reveals only two common compounds (eugenol, terpinen-4-ol). To measure the antioxidative activities of the essential oil and enzymatically released aglycones from nutmeg, two different assays were performed: the 2,2\u27-diphenyl-1-picrylhydrazyl radical scavenging method (DPPH) and the ferric reducing / antioxidant power assay (FRAP). Both methods showed that the aglycone fraction possesses stronger antioxidant properties than free volatiles from the oil

Chemical Composition and Antioxidant Effect of Free Volatile Aglycones from Nutmeg (Myristica fragrans Houtt.) Compared to Its Essential Oil

The paper reports on the isolation of glycosidically bound volatiles from nutmeg, identification of free aglycones, and determination of the antioxidative power of free aglycones in comparison with nutmeg essential oil. Comparison of the chemical composition of free volatiles with the chemical composition of free volatile compounds found in the essential oil reveals only two common compounds (eugenol, terpinen-4-ol). To measure the antioxidative activities of the essential oil and enzymatically released aglycones from nutmeg, two different assays were performed: the 2,2\u27-diphenyl-1-picrylhydrazyl radical scavenging method (DPPH) and the ferric reducing / antioxidant power assay (FRAP). Both methods showed that the aglycone fraction possesses stronger antioxidant properties than free volatiles from the oil

Chemical Composition and Antioxidant Activity of Essential Oils of Twelve Spice Plants

Chemical compositions and related total antioxidant capacities of twelve spice essential oils were analyzed. To enable a comparison of their relative antioxidant potentials, essential oils were extracted by hydrodistillation from selected spice plants and their chemical compositions were determined by the GC-MS system on two fused-silica capillary columns of different polarity. Antioxidant effectiveness was examined by four different methods: the 2,2\u27-diphenyl- 1-picrylhydrazyl (DPPH) radical scavenging method, determination of ferric reducing antioxidant power (FRAP), determination of antioxidant activity with thiobarbituric acid reactive species (TBARS) and automatic determination of the oxidative stability of fat (RANCIMAT). Based on their antioxidant capacity, twelve spice essential oils can be sorted in descending order: Clove (Syzygium aromaticum L.) > Basil (Ocimum basilicum L.) > Laurel (Laurus nobilis L.) > Coriander (Coriandrum sativum L.) > Nutmeg (Myristica fragrans Houtt.) > Black Pepper (Piper nigrum L.) > Everlast (Helichrysum italicum G. (Roth) Don) > Mint (Mentha piperita L.) > Marjoram (Marjorana hortensis Moench.) > Cinnamon (Cinnamomum zeylanicum Nees) > Sage (Salvia officinalis L.) > Fennel (Foeniculum vulgare Muller)

Chemical Composition and Antioxidant Activity of Free Volatile Aglycones from Laurel (Laurus nobilis L.) Compared to Its Essential Oil

The paper examines the chemical composition and antioxidant activity of free volatile aglycones from laurel (Laurus nobilis L.) as compared to its essential oil. Comparison of the chemical composition of volatile aglycones with the chemical composition of essential oil showed there was no similarity between the free compounds found in the essential oil and the corresponding volatile aglycones. Only eugenol was found to be identical. To evaluate the said antioxidant activities, two different methods were applied: 2,2’-diphenyl-1-picrylhydrazyl radical scavenging method (DPPH) and ferric reducing/antioxidant power assay (FRAP). The results obtained in vitro with both methods showed that volatile aglycones from laurel possess lower reducing power and free radical scavenging ability compared to essential oil as well as the well-known synthetic antioxidant butilated hydroxytoluene (BHT)

Chemical Composition and Antioxidant Activity of Essential Oils of Twelve Spice Plants

Chemical compositions and related total antioxidant capacities of twelve spice essential oils were analyzed. To enable a comparison of their relative antioxidant potentials, essential oils were extracted by hydrodistillation from selected spice plants and their chemical compositions were determined by the GC-MS system on two fused-silica capillary columns of different polarity. Antioxidant effectiveness was examined by four different methods: the 2,2\u27-diphenyl- 1-picrylhydrazyl (DPPH) radical scavenging method, determination of ferric reducing antioxidant power (FRAP), determination of antioxidant activity with thiobarbituric acid reactive species (TBARS) and automatic determination of the oxidative stability of fat (RANCIMAT). Based on their antioxidant capacity, twelve spice essential oils can be sorted in descending order: Clove (Syzygium aromaticum L.) > Basil (Ocimum basilicum L.) > Laurel (Laurus nobilis L.) > Coriander (Coriandrum sativum L.) > Nutmeg (Myristica fragrans Houtt.) > Black Pepper (Piper nigrum L.) > Everlast (Helichrysum italicum G. (Roth) Don) > Mint (Mentha piperita L.) > Marjoram (Marjorana hortensis Moench.) > Cinnamon (Cinnamomum zeylanicum Nees) > Sage (Salvia officinalis L.) > Fennel (Foeniculum vulgare Muller)

Pseudophakic Cystoid Macular Oedema (PCME) Prevention in Patients with Non-Proliferative Diabetic Retinopathy (NPDR)—Randomized Controlled Trial

Background and Objectives: The purpose of this study was to compare the effect of topical bromfenac and dexamethasone on the intraocular concentration of interleukin 6 (IL-6) and incidence of pseudophakic cystoid macular oedema (PCME) after cataract surgery in patients with non-proliferative diabetic retinopathy (NPDR). Materials and Methods: Ninety eyes of patients with mild-to-moderate NPDR that underwent phacoemulsification cataract surgery were divided into three groups. A detailed description of the clinical study protocol is described later in paper. In short, Group 1 received topical bromfenac (0.9 mg/mL), Group 2 dexamethasone (1 mg/mL), and Group 3 placebo, both preoperatively and postoperatively. Additionally, all patients received combined topical steroid and antibiotic drops (dexamethasone, neomycin and polymyxin B) 3 weeks postoperatively. On the day of the surgery, aqueous humour samples (0.1–0.2 mL) were obtained and IL-6 concentrations were analysed. Central foveal subfield thickness (CFT) measured using spectral-domain optical coherence tomography (SD-OCT) was analysed preoperatively and postoperatively. Results: There was no significant difference in IL-6 concentrations between groups. Postoperative CFT was significantly lower in the dexamethasone group compared to the placebo group. In addition, the correlation between IL-6 and CFT was statistically significant in the dexamethasone group. No patient developed PCME in any of the three groups. No adverse events were reported during the study. Conclusion: Topical bromfenac and dexamethasone have no significant effect on intraocular IL-6 concentration in patients with NPDR. Topical bromfenac is not more effective than topical dexamethasone in reducing postoperative CFT in patients with NPDR

Spojevi s antioksidacijskim djelovanjem iz vodenih infuzija različitih biljaka kao potencijalni inhibitori enzima acetilkolinesteraze

A study of antioxidant activity and acetylcholineste ase (AChE) inhibitory activity of aqueous tea infusions prepared from walnut (Juglans regia L.), peppermint (Mentha×piperita L.), strawberry (Fragaria×ananassa L.), lemon balm (Melissa officinalis L.), sage (Salvia officinalis L.), and immortelle (Helichrysum arenarium (L.) Moench.) is presented here. Chemical composition of selected aqueous tea infusions was determined by high-performance liquid chromatography with photodiode-array method (HPLC-PDA), and the following phenolic compounds were identified as dominant: rosmarinic acid, gallic acid (not identified in walnut and sage), caffeic acid (in sage and peppermint), neochlorogenic acid, 3-p-coumaroylquinic acid and quercetin 3-galactoside (in walnut) and luteolin 7-O-glucoside (in sage). Antioxidant activity of the selected aqueous tea infusions was measured using low-density lipoprotein (LDL) oxidation method, 2,2\u27-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging test, β-carotene bleaching method, and Rancimat method (induction period of lard oxidation). Strawberry and lemon balm aqueous infusions completely inhibited LDL oxidation at the concentration of 0.005 g/L in the reacting system. Very long prolongation of the lag phase was achieved with peppermint and sage aqueous infusions. All tested infusions in the concentration range of 0.05–2.85 g/L showed very pronounced effect of DPPH scavenging activity (90–100 %) as well as the inhibition of β-carotene bleaching (89–100 %). In pure lipid medium, used in Rancimat method, sage and immortelle at the concentration of 0.16 % (by mass) had the highest ability to inhibit lipid peroxidation process. Screening of the AChE inhibitory activity by Ellman´s method showed that the strongest inhibition was obtained with walnut and strawberry aqueous infusions at the concentration of 1.36 g/L in the reacting system. The presented results suggest that natural antioxidants could be useful and merit further investigations in the treatment and prevention of Alzheimer’s disease.Svrha je istraživanja bila odrediti antioksidacijsko djelovanje i sposobnost inhibicije enzima acetilkolinesteraze u vodenim infuzijama oraha (Juglans regia L.), paprene metvice (Mentha × piperita L.), jagode (Fragaria × ananassa L.), matičnjaka (Melissa officinalis L.), kadulje (Salvia officinalis L.) i smilja (Helichrysum arenarium (L.) Moench.). HPLC-PDA analizom utvrđeno je da u vodenim infuzijama odabranih biljaka najviše ima fenolnih kiselina (ružmarinske, galne, kafeinske, neoklorogenske i 3-p-kumaroil-kinske kiseline), te flavonola (kvercetin-3-galaktozid i luteolin-7-glukozid). Antioksidacijsko djelovanje vodenih infuzija određeno je LDL metodom (sprječavanje oksidacije lipoproteina male gustoće), DPPH metodom, metodom izbjeljivanja ß-karotena i Rancimat metodom (produženi proces oksidacije masti). Utvrđeno je da vodene infuzije jagode i matičnjaka potpuno sprječavaju oksidaciju LDL-a pri koncentraciji od 0,005 g/L u sustavu, te da je izrazito produžena lag faza tijekom oksidacije LDL-a uzrokovana djelovanjem vodenih infuzija paprene metvice i kadulje. Nadalje, testirane infuzije u rasponu koncentracija od 0,05 do 2,85 g/L pokazale su jako visoki stupanj uklanjanja DPPH radikala (90-100 %) i sprječavanja izbjeljivanja ß-karotena (89-100 %). Rancimat metodom utvrđeno je da vodene infuzije kadulje i smilja (masenog udjela od 0,16 %) najviše utječu na odgađanje procesa oksidacije masti. Inhibicija enzima acetilkolinesteraze pomoću testiranih vodenih infuzija određena je Ellmanovom metodom, pri čemu su vodene infuzije oraha i jagode (u koncentraciji od 1,36 g/L u sustavu) pokazale najveći stupanj inhibicije acetilkolinesteraze. Dobiveni rezultati upućuju na to da prirodni antioksidansi svojim djelovanjem mogu pridonijeti poboljšanju terapije i prevenciji Alzheimerove bolesti

Antioxidant and Acetylcholinesterase Inhibiting Activity of Several Aqueous Tea Infusions in vitro

A study of antioxidant activity and acetylcholineste ase (AChE) inhibitory activity of aqueous tea infusions prepared from walnut (Juglans regia L.), peppermint (Mentha×piperita L.), strawberry (Fragaria×ananassa L.), lemon balm (Melissa officinalis L.), sage (Salvia officinalis L.), and immortelle (Helichrysum arenarium (L.) Moench.) is presented here. Chemical composition of selected aqueous tea infusions was determined by high-performance liquid chromatography with photodiode-array method (HPLC-PDA), and the following phenolic compounds were identified as dominant: rosmarinic acid, gallic acid (not identified in walnut and sage), caffeic acid (in sage and peppermint), neochlorogenic acid, 3-p-coumaroylquinic acid and quercetin 3-galactoside (in walnut) and luteolin 7-O-glucoside (in sage). Antioxidant activity of the selected aqueous tea infusions was measured using low-density lipoprotein (LDL) oxidation method, 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging test, β-carotene bleaching method, and Rancimat method (induction period of lard oxidation). Strawberry and lemon balm aqueous infusions completely inhibited LDL oxidation at the concentration of 0.005 g/L in the reacting system. Very long prolongation of the lag phase was achieved with peppermint and sage aqueous infusions. All tested infusions in the concentration range of 0.05–2.85 g/L showed very pronounced effect of DPPH scavenging activity (90–100 %) as well as the inhibition of β-carotene bleaching (89–100 %). In pure lipid medium, used in Rancimat method, sage and immortelle at the concentration of 0.16 % (by mass) had the highest ability to inhibit lipid peroxidation process. Screening of the AChE inhibitory activity by Ellman´s method showed that the strongest inhibition was obtained with walnut and strawberry aqueous infusions at the concentration of 1.36 g/L in the reacting system. The presented results suggest that natural antioxidants could be useful and merit further investigations in the treatment and prevention of Alzheimer’s disease