Bijen Kivcak

Disposable electrochemical biosensor for the detection of the interaction between DNA and lycorine based on guanine and adenine signals

The interaction of lycorine (LYC) with calf thymus double stranded DNA (dsDNA) and calf thymus single stranded DNA (ssDNA) was studied electrochemically based on the oxidation signals of guanine and adenine by using differential pulse voltammetry (DPV) at carbon paste electrode (CPE) and pencil graphite electrode (PGE). As a result of the interaction of LYC with DNA, the voltammetric signal of guanine and adenine greatly decreased. The changes in the experimental parameters such as the concentration of LYC, and the accumulation time of LYC were studied by using DPV with PGE. The interaction of LYC with synthetic polynucleotides, such as poly[G] was also observed. The interaction of LYC with dsDNA was also observed at PGE in solution phase. In addition, the detection limit and the reproducibility was determined by using both electrochemical transducers. The application of electrochemical methods on the interactions between DNA and DNA targeted agent were explored.

Efficiency of ellagic acid and arbutin in melasma: A randomized, prospective, open-label study

The aim of this study was to compare the effectiveness of gel formulations containing arbutin, synthetic ellagic acid and plant extracts that contain ellagic acid, on patients with melasma. Thirty patients who applied to Ege University Medical Faculty, Department of Dermatology, were included in the study. A signed consent was obtained from each patient prior to study. Patients whose type of melasma was determined via Woods lamp were randomized to groups of arbutin, synthetic ellagic acid and plant extract containing natural ellagic acid. The pigment density of patients was evaluated via Mexameter before and after the treatment. The approval of the Institutional Ethics Committee of Ege University was obtained before the study. Wilcoxon and Kruskal–Wallis tests were used in the statistical analysis. Nine of 10 patients, for whom synthetic ellagic acid was started, completed the study. A decrease in the level of melanin was determined in eight of these nine patients (P = 0.038). A significant decrease in the level of melanin was also determined in all 10 patients who used plant extract containing ellagic acid (P = 0.05). A significant response was obtained from all of 10 patients who used arbutin. The difference between pre‐ and post‐treatment levels of melanin was statistically significant (P = 0.05). Formulations prepared with plant extracts containing ellagic acid was found effective on melasma, similar to the formulations containing synthetic ellagic acid and arbutin. This material that is not yet being used widespread commercially on melasma could be an effective alternative for treatment of melasma.

Alkaloids of Galanthus elwesii

Abstract Six new lycorenine-type alkaloids, (+)-5-methoxy-9- O -demethylhomolycorine, (+)-galwesine, (+)-9- O -demethylgalwesine, (+)-16-hydroxygalwesine, (+)-16-hydroxy-9- O -demethylgalwesine and galasine, were isolated from whole plants of Galanthus elwesii . Additionally, 12 known alkaloids, (−)-galanthamine, (−)-sanguinine, (−)-leucotamine, (−)- O -methylleucotamine, (±)-narwedine, (−)- N -demethylgalanthamine, (+)-11-hydroxyvittatine, (+)-9- O -demethylhomolycorine, (−)-lycorine, (−)-galanthine, hordenine, and ( E )- N -feruloyltyramine were also obtained. Of these alkaloids, only galanthamine and lycorine have been isolated previously from G. elwesii . Identification and structural elucidation were achieved using spectrometric techniques.

Antityrosinase Activity of Some Plant Extracts and Formulations Containing Ellagic Acid

Abstract Ellagic acid (EA) is a naturally occurring polyphenol found in a variety of plants in its free form or in the form of ellagitannin glycosides. In this study, the ellagic acid content of the methanol extracts of Juglans regia. L. (Juglandaceae) leaves, Castanea sativa. Mill. (Fagaceae) stem bark, and Eucalyptus camaldulensis. Dehnh. (Myrtaceae) leaves was determined to develop melanogenesis inhibitors. An improved NaNO2 assay was used for determination of EA. The tyrosinase inhibitory activity of the extracts and synthetic EA was tested in vitro. by monitoring the appearance of dopachrome, an intermediate in the melanogenesis process. The results were compared keeping the same total concentration of inhibitor. The efficacy of EA (1%) was compared with arbutin (1%) and hydroquinone monomethyl ether (1%) as reference substances, and it was found to be a more efficient suppressor of pigmentation. The effect of formulation variables on the tyrosinase inhibitory activity was also evaluated. Based on dopachrome tests performed in the formulations, it could be concluded that the combination with plant extracts had a synergistic effect, and gel formulation could be suggested as an effective carrier for treating uneven skin pigmentation.

Chemical Composition of Essential Oils from Leaves and Twigs of Pistacia lentiscus, Pistacia lentiscus var. chia, and Pistacia terebinthus from Turkey

The composition of the essential oils from the leaves and twigs of Pistacia lentiscus L., Pistacia lentiscus var. chia (L.), and Pistacia terebinthus L. of Turkish origin were analyzed by gas chromatography/mass spectrometry (GC/MS). Seventy-seven constituents were characterized from the essential oil of P. terebinthus leaves with α-cadinol (6.9%), phytol (5.4%), δ-cadinene (5.1%), α-terpineol (5.0%), and bornyl acetate (4.4%) as major constituents. Germacrene D (10%), β-pinene (7.5%), bornyl acetate (6.0%), α-cubebene (5.9%), and cubebol (5.4%) were found to be the main components among the 61 compounds characterized in the essential oil of P. terebinthus twigs. Forty-six compounds were characterized from the essential oil of P. lentiscus twigs with sabinene (23.2%), α-pinene (19.4%), germacrene D (14.1%), limonene (6.9%), β-phellandrene (6.5%), terpinene-4-ol (5.7%), and β-caryophyllene (5.7%) as the main constituents. Terpinene-4-ol (29.2%), β-caryophyllene (29.2%), and p-cymene (7.1%) were identified as the major components among the 64 compounds characterized in the essential oil of P. lentiscus leaves. Sixty-eight compounds were found on the essential oil of P. lentiscus var. chia leaves with germacrene D (20.1%), myrcene (13.9%), β-caryophyllene (10.8%), and α-terpinyl acetate (4.8%) as the major constituents. Myrcene (27.4%), germacrene D (21.7%), and β-caryophyllene (7.2%) were found to be the main components among 50 compounds characterized in the essential oil of P. lentiscus var. chia twigs.

Effects of Ginkgo biloba on airway histology in a mouse model of chronic asthma.

Platelet-activating factor (PAF) is an inflammatory mediator involved in the pathophysiology of asthma, suggesting a therapy antagonizing its effects may play a role in the disease treatment. The aim of the study was to determine the effects of Ginkgo biloba, a PAF antagonist, on lung histology. Thirty-five BALB/c mice were divided into five groups; A, B, C, D, and the control. All mice except controls were sensitized and challenged with ovalbumin. Mice in group A (placebo) received saline; group B received G. biloba, 100 mg/kg; group C received G. biloba, 150 mg/kg; and group D received dexamethasone, 1 mg/kg via orogastric gavage for 7 consecutive days. Chronic structural changes and airway remodeling were evaluated by using light and electron microscopy in all groups. Evaluation of lung histology indicated that the number of goblet cells, mast cells, thicknesses of epithelium, and basement membrane were significantly improved in groups B and C when compared with group A. There was no statistically significant difference in thicknesses of subepithelial smooth muscle between groups A, B, and C. When doses of G. biloba were compared with each other, only the number of goblet cells was significantly lower in group C than in group B. When G. biloba and dexamethasone groups were compared with each other, thicknesses of basement membrane and subepithelial smooth muscle were found to be lower in group D than in groups B and C. G. biloba alleviates all established chronic histological changes of lung except smooth muscle thickness in a mouse model of asthma.

Ginseng ameliorates chronic histopathologic changes in a murine model of asthma.

Currently, asthma therapies are effective in reducing inflammation but airway remodeling is poorly responsive to these agents. New therapeutic options that have fewer side effects and reverse chronic changes in the lungs are essential. This study aimed to determine the efficacy of oral administration of ginseng on lung histopathology in a murine model of chronic asthma. BALB/c mice were divided into four groups: control, placebo, ginseng, and dexamethasone. All mice except those in the control group were sensitized and challenged with ovalbumin. Then, mice in the ginseng group were given 2 gr/kg per day of ginseng and mice in the dexamethasone group received 1 mg/kg per day of dexamethasone via orogastic gavage once daily for 1 week. Lung histopathology was evaluated by using light and electron microscopy in all groups. All of the chronic changes of airways in the ginseng group were significantly ameliorated when compared with the placebo group. When compared with the dexamethasone group, the ginseng group had significantly lower numbers of mast cell count. Thicknesses of basement membrane, epithelium, and subepithelial smooth muscle were not statistically different between the ginseng and dexamethasone groups. Goblet cell numbers were much more reduced in the dexamethasone group. Ginseng is effective in resolving the established chronic histopathological changes of the lungs in the murine model of asthma.

Chemical composition and antimicrobial activity of the essential oil of Anthemis wiedemanniana from Turkey

The chemical composition and antimicrobial activity of the essential oil from aerial parts of Anthemis wiedemanniana, an endemic taxon of Turkey, were investigated. Linalool (12.75%), 1,8-cineole (8.49%), hexadecanoic acid (6.09%), and chrysanthenone (5.67%) were found to be the main components among the 122 compounds characterized in the essential oil of Anthemis wiedemanniana. Antimicrobial activities were reported against 12 microorganisms and five yeast-like fungi by the disc diffusion method.

Chemical composition and antimicrobial activity of the essential oils of three Anthemis species from Turkey

The genus Anthemis L. of Asteraceae (Compositae) is represented in the Flora of Turkey by 81 taxa belonging to 51 species, 29 of which are endemic to Turkey. One of the endemic species is A. dipsacea Bornm. A. pectinata Boiss.& Reuter var. pectinata and A. dipsacea are distributed in western regions of Turkey. A. pseudocotula Boiss. grows wild in the western, eastern, and southern regions of Turkey. A detailed botanical description of the studied three species is presented in Flora of Turkey [1]. All of these Anthemis species are called as “Papatya” in Turkey, and infusions of A. pseudocotula are used in Turkish traditional medicine especially for hemorrhoid [2]. Papatya is a common name given to plants whose flowers resemble those of Roman and German chamomile. Many Anthemis spp. are used as herbal tea and for food flavoring, as well as cosmetics and in the pharmaceutical industry [3–5]. Their extracts, tinctures, salves, and tisanes are widely used as antispasmodic, anti-inflammatory, and antibacterial in Europe. The occurrence of sesquiterpene lactones, flavonoids, and essential oils in various Anthemis species has been reported in previous works [6–12].

COMPOSITION OF THE ESSENTIAL OIL OF Arbutus unedo

Water-distilled essential oil from leaves ofArbutus unedoL. of Turkish origin was analyzed by GC/MS. Thirty-seven constituents were characterized with (E)-2-decenal (12.0 %), α-terpineol (8.8 %), hexadecanoic acid (5.1 %), and (E)-2-undecenal ( 4.8 %) as the major constituents.