Gülnur Toker

Exploring the wound healing activity of Arnebia densiflora (Nordm.) Ledeb. by in vivo models

ETHNOPHARMACOLOGICAL RELEVANCE The roots of Arnebia densiflora (Nordm.) Ledeb. (Boraginaceae), which is an endemic plant for Turkey, have been used for healing of wounds in folk medicine. The extract of the roots in olive oil and mostly the root barks was applied onto open wounds for rapid healing. AIM OF THE STUDY To evaluate the wound healing activity of the roots, extracts were prepared with different solvents; hexane, chloroform, ethyl acetate and methanol, respectively from the roots of Arnebia densiflora. MATERIALS AND METHODS Incision by using tensiometer and excision models were employed on mice and rats. RESULTS Significant wound healing activity was observed with the ointment formulation prepared by using hexane extract at 1% concentration on the mentioned models. The results of histopathological examination supported the outcome of both incision and excision wound models. The wound healing effect was comparatively evaluated with a reference ointment Madecassol. CONCLUSION The experimental data demonstrated that Arnebia densiflora displayed remarkable wound healing activity.

Antiviral and antimicrobial assessment of some selected flavonoids

Abstract In the current study, the results of antibacterial, antifungal, and antiviral activity tests of four flavonoid derivatives, scandenone (1), tiliroside (2), quercetin-3,7-O-α-ʟ-dirhamnoside (3), and kaempferol-3,7-O-α-ʟ-dirhamnoside (4), are presented. Antibacterial and antifungal activities of these compounds were tested against Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis, Klebsiella pneumoniae, Acinetobacter baumannii, Staphylococcus aureus, Bacillus subtilis, and Enterococcus faecalis, as well as the fungus Candida albicans by a microdilution method. On the other hand, both DNA virus Herpes simplex (HSV) and RNA virus Parainfluenza-3 (PI-3) were employed for antiviral assessment of the compounds using Madin- Darby bovine kidney and Vero cell lines. According to our data, all of the compounds tested were found to be quite active against S. aureus and E. faecalis with MIC values of 0.5 μg/ml, followed by E. coli (2 μg/ml), K. pneumoniae (4 μg/ml), A. baumannii (8 μg/ml), and B. subtilis (8 μg/ml), while they inhibited C. albicans at 1 μg/ml as potent as ketoconazole. However, only compound 3 displayed an antiviral effect towards PI-3 in the range of 8- 32 μg/ml of inhibitory concentration for cytopathogenic effect (CPE).

Comparative evaluation of the flavonoid content in officinal Tiliae flos and Turkish lime species for quality assessment

Lime flowers are used for various medicinal purposes in phytotherapy. Flavonoids, volatile oil and mucilage components are known as the active ingredients. In European Pharmacopoeia (EP), a simple thin-layer chromatographic (TLC) technique, which based on the analysis of the flavonoid composition was defined for the qualitative analysis of the drug. In this study, flavonoid composition in the flowers, bracts and leaves of the officinal species, Tilia platyphyllos were studied using a reversed-phase high performance liquid chromatographic (HPLC) technique, in order to develop a rapid, reliable and accurate method for quantitative analysis. The results were further compared with in those parts of two common species growing in Turkey, Tilia rubra and Tilia argentea. Results of the present study revealed that flavonoid composition of each lime species possesses a specific fingerprint HPLC chromatogram depending upon the parts used and evaluation of the data might be helpful in the quality assurance as well as determination of adulteration of the crude drug.

Anti-ulcerogenic activity and isolation of the active principles from Sambucus ebulus L. leaves.

ETHNOPHARMACOLOGICAL RELEVANCE Sambucus ebulus L. has a very prominent place in Turkish folk medicine. Leaves of the plant are practiced externally to relieve rheumatic pain, to treat abscess, for wound healing and internally against hemorrhoids and stomachache. In a previous work, aqueous extract of the leaves was shown to possess potent antiulcerogenic activity on water immersion and immobilization-induced stress ulcer model in rats. This study aims to investigate the antiulcerogenic activity profile of the plant on various in vivo peptic ulcer models and gastric biochemical parameters and through bioassay-guided processing to isolate the active constituent (s) and to elucidate its structure. MATERIALS AND METHODS Among the subextracts obtained by successive solvent extractions from the MeOH extract of the leaves, the butanol subextract exerted significant antiulcerogenic activity against water-immersion and immobilization-induced stress ulcer model in rats as the bioassay model. This subextract was then subjected to successive chemical separation techniques (precipitation, column chromatography based on ion-exchange, silica gel and sephadex) and the activity of each fraction/subfraction was tested using the same bioassay model. After determination of active principles, further studies were performed on the active subextract by using various in vivo test models (ethanol-, serotonin-, pyloric ligation-induced ulcerogenesis) in rats as well as biochemical methods for the evaluation of antiulcerogenic potential. RESULTS Bioassay-guided fractionation procedures yielded two flavonol glycosides as the active antiulcerogenic principles. The structures of these compounds were elucidated as isorhamnetin-3-O-monoglycoside and quercetin-3-O-monoglycoside by using (1)H, (13)C-NMR, and FAB-MS techniques. CONCLUSION This study has proven the folkloric use of Sambucus ebulus leaves for the treatment of gastric ailments in Turkish folk medicine. The antiulcerogenic activity of the two flavonol glycosides isolated in the present study was not previously reported elsewhere.

Callus formation and cucurbitacin B accumulation in Ecballium elaterium callus cultures.

Ecballium elaterium fruit juice is used for the treatment of sinusitis in Turkish folk medicine. The aim of this study was to increase the yield of cucurbitacin B, an anti-inflammatory compound previously isolated in various organs of E. elaterium, through tissue culture techniques. Higher yields of cucurbitacin B (1.126%) were obtained from the first subculture calluses from stem nodes in the presence of benzyl adenine (BA; 1 mg/l) and naphtalene acetic acid (NAA; 0.1 mg/l) in comparison with the yields obtained from plant material (0.01%).

An in vitro perspective to cholinesterase inhibitory and antioxidant activity of five Gentiana species and Gentianella caucasea.

The dichloromethane (DCM), ethyl acetate (EtOAc), and methanol extracts from the leaves, roots, and flowers of the five species of Gentiana (Gentiana asclepiadea, Gentiana cruciata, Gentiana olivieri, Gentiana septemfida, and Gentiana verna) and Gentianella caucasea were investigated for their inhibitory activity against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) and antioxidant effect using 2,2-diphenyl-1-picrylhydrazyl radical scavenging, metal-chelation capacity, and ferric-reducing antioxidant power assays. Total phenol and flavonoid contents of the extracts were determined spectrophotometrically. The presence of some characteristic compounds found in Gentiana species (gentiopicroside, swertiamarin, isoorientin, isovitexin and vitexin) was analyzed in the extracts by thin layer chromatography. The flower DCM extract of G. verna exerted the highest inhibition against AChE (53.65 ± 1.03%), whereas the root EtOAc extract of G. cruciata was the most effective in BChE inhibition assay (50.72 ± 0.75%) at 100 μg ml− 1. The extracts of G. verna were also found to be more active in the antioxidant tests.

The Composition of Essential Oils from Tilia L. Species Growing in Turkey

Abstract Essential oil from the flowers, bracts and leaves of Tilia platyphyllos Scop., T. rubra DC. and T. argentea Desf. ex DC. growing in Turkey were examined by GC/MS. The composition of the essential oils showed differences. The essential oils from the flowers of T. platyphyllos and T. rubra were characterized by a high percentage of hydrocarbons (47.5–66.5%), whereas T. argentea flowers were rich in esters (34.8%). Esters were also in high amount in the bracts of T. argentea (27.0%). The high content of aliphatic acids were found in the all parts of T. platyphyllos (28.3–37.1%), T. argentea (29.4–41.0%) and bracts of T. rubra(30.M). Kaur-l6-ene (29.3% and 41.9%) was the major constituent in the leaf oils of T. rubra and Tplatyphyllos, respectively. It was also the main constituent of the bract oil of the latter (25.8%). Hexadecanoic acid, 2-phenethyl benzoate, β-ionone, geranyl acetone, farnesyl acetone and hexahydrofarnesyl acetone were characterized as the main oxygenated constituents.

Alkaloids of Bongardia chrysogonum

Two new pyridine alkaloids were isolated from the tubers of Bongardia chrysogonum, together with a new lupine alkaloid. The structures of the new alkaloids were characterized by spectroscopic analysis and the stereochemistry was confirmed by applying Horeaus method.

Anatomical investigations on root, stem, and leaf of Gentiana olivieri Griseb

Background: Gentiana olivieri Griseb. (Afat) (Gentianaceae), which has many bioactive compounds is used as antidiabetic, hepatoprotective, digestive aid, antidepressant, and antianemic in traditional medicine. Materials and Methods: Root, stem, and leaf sections of G. olivieri were taken free hand or by sliding microtome and examined on light microscope. Results: Anatomical characters of the species were observed to be similar to the usual features of Gentianaceae anatomy. Conclusion: Intraxylary phloem, which was primarily the distinguishing feature between Gentianoideae and Menyanthoideae sub-families was observed in G. olivieri roots.

New Alkaloids from Bongardia Chrysogonum

Abstract Two new alkaloids, 17-desoxy-cfs-lamprolobine (1) and bonzakaline (2), along with the known alkaloids lupanine (3) and palmatrubine (4), have been isolated from the ethanolic extracts of Bongardia chrysogonum. Compounds 1 and 2 have shown antibacterial activity against Proteus mirabilis, Proteus vulgaris, Klebsiella pneumoniae, Escherichia coli and Shigella dysenteriae. the structure elucidation was performed by using various spectroscopic methods including 2D NMR techniques1,2.