Ayşegül Güvenç

Comparative analysis of flavonoid profile, antioxidant and antimicrobial activity of the berries of Juniperus communis L. var. communis and Juniperus communis L. var. saxatilis Pall. from Turkey.

The present study was designed to define and compare the flavonoid composition and the biological potential of berries methanol extracts of Juniperus communis L. var. communis (Jcc) and Juniperus communis L. var. saxatilis. Pall. (Jcs) from Turkey. Total polyphenols (Folin-Ciocalteau method) were 3-fold higher in Jcc (59.17 +/- 1.65 mg GAE/g extract) than in Jcs (17.64 +/- 0.09 mg GAE/g extract). Flavonoid and biflavonoid content, evaluated by HPLC-DAD-ESI-MS analysis, was higher in Jcc (25947 +/- 0.86 and 4346 +/- 3.95 microg/g extract) than in Jcs (5387 +/- 34.88 and 1944 +/- 26.88 microg/g extract). The HPLC analysis of Jcc allowed the separation of 16 flavonoids; hypolaetin-7-pentoside and quercetin-hexoside are the main compounds. Moreover, gossypetin-hexoside-pentoside and gossypetin-hexoside were identified for the first time in Jcc berries. In Jcs eight flavonoids were identified: quercetin-hexoside and isoscutellarein-8-O-hexoside are the most abundant compounds. The in vitro antioxidant activity was determined using different methods; Jcc was found to be more active than Jcs in the DPPH test (IC(50) of 0.63 +/- 0.09 mg/mL and 1.84 +/- 0.10 mg/mL) in reducing power assay (12.82 +/- 0.10 ASE/mL and 64.14 +/- 1.20 ASE/mL), and in TBA assay (IC(50) of 4.44 +/- 0.70 microg/mL and 120.07 +/- 3.60 microg/mL). By contrast, Jcs exhibited more elevated Fe(2+) chelating ability than Jcc. The extracts were also studied for their antimicrobial potential, displaying antimicrobial capacity only against Gram-positive bacteria.

Antimicrobial activity of the extracts and physalin D from Physalis alkekengi and evaluation of antioxidant potential of physalin D

Physalis alkekengi L. (Solanaceae) is a popular plant in traditional European and Chinese folk medicine, and it has been reported to have many ethnopharmacological properties including antifungal, anti-cough, anti-inflammatory, analgesic, and febricide activities. Some active components from Physalis species have been investigated. However, no antimicrobial activity studies on extracts and physalins of P. alkekengi have been carried out. In this study, we attempted to identify the possible antimicrobial activities of the methanol extract from aerial parts of P. alkekengi and the dichloromethane extract from calyces of the plant. The extracts were tested against five Gram-positive and five Gram-negative bacteria and five Candida species by using disk diffusion and broth microdilution methods. The extracts were fractionated to isolate physalins using chromatographic techniques, and physalin D was isolated from the extracts. The structure of the compound was elucidated on the basis of 1H-NMR spectroscopic study, and confirmed by comparison with a reference sample and literature data. Results indicated that all the extracts and physalin D were characterized by antibacterial action, especially against Gram-positive bacteria, with MIC values between 32 and 128 μg/mL. The methanol extract had moderate activity against fungi at MICs ranging from 128 to 512 μg/mL, but the dichloromethane extract and physalin D had low activity against fungi at MICs ranging from 256 to 512 μg/mL. Additionally, the antioxidant activity of physalin D was evaluated by qualitative DPPH (1,1-diphenyl-2-picrylhydrazyl) radical and TBA (thiobarbituric acid) assays. Physalin D showed low antioxidant activity with an IC50 value of ≥ 10 ± 2.1.

A comparative study on the antinociceptive and anti-inflammatory activities of five Juniperus taxa.

ETHNOPHARMACOLOGICAL RELEVANCE Juniperus L. (Cupressaceae) species have been used to various inflammatory and infectious diseases such as bronchitis, colds, cough, fungal infections, hemorrhoids, gynecological diseases, and wounds in Turkish folk medicine. AIM OF THE STUDY To evaluate this traditional information, anti-inflammatory and antinociceptive activities of the methanolic and aqueous extracts prepared from different parts (stem, fruit and leaves) of the five Turkish taxa under Juniperus section of the gender; J. drupacea, J. communis var. communis, J. communis var. saxatilis, J. oxycedrus subsp. oxycedrus, and J. oxycedrus subsp. macrocarpa growing were investigated. METHODS For the anti-inflammatory activity, carrageenan-induced and PGE(2)-induced hind paw edema models, and for the antinociceptive activity p-benzoquinone-induced writhing and hot plate tests in mice were employed. RESULTS The methanolic extracts of fruit and leaves from J. oxycedrus subsp. oxycedrus and J. communis var. saxatilis exhibited notable inhibition in carrageenan-induced edema model at a dose of 100mg/kg. The same extracts also displayed significant activity against PGE(2)-induced edema model. While, the remaining extracts were found inactive against these edema models. A similar activity pattern was observed against p-benzoquinone-induced abdominal constriction test without inducing any gastric damage or apparent acute toxicity, whereas all extracts were inactive in hot plate test. CONCLUSION The experimental data demonstrated that J. oxycedrus subsp. oxycedrus and J. communis var. saxatilis displayed remarkable anti-inflammatory and antinociceptive activities; however, further studies are warranted to define and isolate the active anti-inflammatory and antinociceptive components from these active species which may yield safe and effective agents to be used in the treatment of inflammatory disorders.

Antioxidant Activity Studies on Selected Sideritis Species Native to Turkey

ABSTRACT Sideritis. L. species are widely used as medicinal plants and as herbal teas in Turkey, in which 45 species of the genus are naturally found. The aim of this study was to determine the antioxidant activity of Sideritis. species found in the Mediterranean region. In this study, the antioxidant activities of the lyophilized extracts obtained from aerial parts of 17 species (18 taxa) of Sideritis. were compared, of which 15 taxa were endemic. The antioxidant activities of aqueous extracts were studied by two different techniques: qualitative DPPH (1,1-diphenyl-2-picrylhydrazyl radical) assay to detect the free radical scavenging activity and the TBA assay to detect liposome lipid peroxidation. All the extracts (except S. erithrantha. subsp. erithrantha., S. dichotoma., S. syriaca. subsp. nusariensis., S. tmolea.) showed a strong antioxidant activity with the DPPH test. High activity was observed in the S. brevibracteata. (IC50 mg/ml = 0.16), S. condensata. (IC50 mg/ml = 0.33), S. serratifolia. (IC50 mg/ml = 0.31) extracts with the lipid peroxidation assay method.

Phenolic composition and biological activities of Juniperus drupacea Labill. berries from Turkey

The present study was designed to define the phenolic profile and the biological potential of berries methanol extract of Juniperus drupacea Labill. from Turkey. The total phenolic content (Folin-Ciocalteau assay) was 48.06±0.99mgGAE/g extract. The HPLC-DAD-ESI-MS analysis allowed the determination of the complete phenolic profile of J. drupacea berries. Phenolic acids represented more than 60% of the total phenolics, and tyrosol was the major one (1324±0.64μg/g extract); within the flavonoids amentoflavone was detected as the main constituent (927±0.35μg/g extract). The extract exhibited good antioxidant properties, as determined by different in vitro models: DPPH test (IC(50) 0.38±0.02mg/mL), reducing power (12.63±0.14ASE/mL), Fe(2+) chelating ability (IC(50) 2.26±0.06mg/mL), and TBA test (IC(50) 2.47±1.13μg/mL). Cytotoxicity against Artemia salina was highlighted (LC(50) 489.47±27.8μg/mL), and a significant decrease (p⩽0.05; p⩽0.01) in HepG2 cells viability was observed at the higher concentrations (5-10μg/mL). The extract displayed good antibacterial activity towards Gram-positive bacteria and in particular Staphylococcus aureus was the most susceptible strain (MIC 78.12μg/mL).

Valuation of anti-inflammatory and antinociceptive activities of Erica species native to Turkey

Erica L. species (Ericaceae) have been popularly used as antirheumatic, diuretic, astringent and treatment of urinary infections. In order to evaluate this information, anti-inflammatory and antinociceptive activities of different extracts prepared with methanol, chloroform, ethyl acetate, n-butanol and water from the aerial parts of Erica arborea L., Erica manipuliflora Salisb., Erica bocquetii (Peşmen) P.F. Stevens and Erica sicula Guss. subsp. libanotica (C.&W. Barbey) P.F. Stevens (Ericaceae) of Turkish origin were investigated by using in vivo methods. For the anti-inflammatory activity, carrageenan-induced hind paw edema model, PGE(2)-induced hind paw edema model, and 12-O-tetradecanoyl-13-acetate (TPA)-induced mouse ear edema model and for the antinociceptive activity p-benzoquinone-induced writhing test in mice were employed. The ethyl acetate extracts of Erica arborea (EAE), Erica bocquetii (EBE) and Erica manipuliflora (EME) exhibited notable inhibition against carrageenan-induced (24.1-32.3%, 23.8-36.1%, 29.2-35.1%, respectively) and PGE(2)-induced (21.2-37.7%, 6.8-29.7%, and 6.2-34.1%, respectively) hind paw edema as well as TPA-induced mouse ear edema models in mice, while the ethyl acetate extract of Erica sicula subsp. libanotica (ESE) (10.7-29.7%) displayed potent anti-inflammatory activity only on the PGE(2)-induced hind paw edema model. However, the remaining extracts were found to be inactive against inflammatory models. Same extracts, i.e., EAE, EBE and EME were also found to exhibit remarkable antinociceptive activity in p-benzoquinone-induced abdominal constriction test at a dose of 100mg/kg (46.5%, 27.7% and 36.3%, respectively).

Biological activities of Pseudevernia furfuracea (L.) Zopf extracts and isolation of the active compounds

ETHNOPHARMACOLOGICAL RELEVANCE Pseudevernia furfuracea (L.) Zopf (Parmeliaceae) is a common epiphytic lichen in the conifer-hardwood forest of Anatolia. This species is used in traditional medicine in Turkey as a treatment for wounds, eczema and hemorrhoids. AIM OF THE STUDY The present study was designed to investigate the active compounds from Pseudevernia. furfuracea, and the isolation studies yielded atraric acid (Aslan et al., 2006) as the major compound and a mixture of methyl hematommate (Baumann, 1960) and methyl chlorohematommate (Bayır et al., 2006). Furthermore, methanolic extract from thalli of Pseudevernia. furfuracea and its fractions and isolates (Aslan et al., 2006; Baumann, 1960; Bayır et al., 2006) were investigated for in vitro antimicrobial and antioxidant activities, and in vivo antinociceptive, anti-inflammatory and wound healing activities. MATERIAL AND METHODS Antimicrobial activities of the samples were determined by using the disc diffusion technique. 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay was used as a rapid TLC screening method to evaluate the antioxidant activity of Pseudevernia. furfuracea. The thiobarbituric acid (TBA) test was used to assess the efficacy of the extracts in protecting liposomes from lipid peroxidation. In vivo inhibitory effect of the extracts on the carrageenan-induced hind paw edema model in mice was studied for the assessment of anti-inflammatory activity. p-Benzoquinone-induced abdominal constriction test was used to explore the antinociceptive effects of the extracts. Moreover, the wound healing potential of the plant extracts that were evaluated by using in vivo incision and excision wound models on rats and mice, were comparatively assessed with a reference ointment Madecassol(®). RESULTS Significant antimicrobial activities were observed against Gram (+) microorganisms and Candida krusei and Candida. dubliniensis in dichloromethane (DCM) and ethyl acetate (EtOAc) extracts and isolates. The methanol (MeOH), DCM and EtOAc extracts of the lichen were found to possess moderate inhibitory activity on lipid peroxidation. Methanolic extract of the lichen was found to possess significant inhibitory activity on the carrageenan-induced hind paw edema model in mice whereas the other fractions did not show any activity. While DCM and EtOAc extracts and fractions showed notable anti-inflammatory activity on carrageenan-induced hind paw edema model without inducing any apparent acute toxicity or gastric damage. Moreover, topical application of the ointment prepared with MeOH extract and EtOAc fraction onto the incised wounds exerted remarkable wound healing activity. CONCLUSION The results of these experimental studies exhibited that nonpolar fractions of Pseudevernia. furfuracea have significant antimicrobial activity against especially Candida species and polar fractions (especially MeOH) display antioxidant, anti-inflammatory, antinociceptive and wound healing activities.

In vitro effect of branch extracts of Juniperus species from Turkey on Staphylococcus aureus biofilm

Methanol and aqueous branch extracts of five Juniperus species were examined for their effects on Staphylococcus aureus ATCC 6538P and S. aureus 810 biofilm. The Turkish plant material was Juniperus communis L. var. communis, J. communis L. var. saxatilis Pall., Juniperus drupacea Labill., Juniperus oxycedrus L. ssp. oxycedrus, J. oxycedrus L. ssp. macrocarpa (Sibth. & Sm.) Ball. The Juniperus extracts were subjected to preliminary phytochemical analysis by thin-layer chromatography. The antimicrobial activity was evaluated using the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC). The effects of the extracts on biofilm formation and preformed biofilm were quantified by both biomass OD and the CFU counting method. The phytochemical screening revealed the presence of polyphenols, coumarins, lignans, steroids, alkaloids and terpenes. For both strains, the MICs of all extracts were in the range of 4.88-78.12 microg mL(-1). On S. aureus ATCC 6538P, the effects of subinhibitory concentration (0.5 MIC) of the extracts were minimal on planktonic growth and on adhering cells, whereas they were greater on biofilm formation. Differently, on S. aureus 810, they showed only a rather low efficacy on biofilm formation. The extracts at 2 MIC demonstrated a good activity on a preformed biofilm of S. aureus ATCC 6538P.

Wound healing and anti-inflammatory activities of the Michauxia L'Hérit (Campanulaceae) species native to Turkey.

ETHNOPHARMACOLOGICAL RELEVANCE The leaves of Michauxia species are used for the treatment of wounds in Turkish traditional medicine. In the present study, wound healing, anti-inflammatory and antioxidant activities of the extracts obtained from the root and herb of 5 species of Michauxia collected in different parts of Turkey were evaluated. MATERIAL AND METHODS In vivo incision and excision wound models were used in order to assess the wound healing effects of the methanolic extracts of the plants. Skin samples were also evaluated histopathologically. In vivo inhibitory effect of the extracts on acetic acid-induced increase in capillary permeability was studied for the assessment of anti-inflammatory activity. TBA (thiobarbituric acid) test, qualitative and quantitative DPPH (2,2-diphenyl-1-picrylhydrazyl) tests were used to evaluate the antioxidant activity. RESULTS Noteworthy wound healing activity was observed for the ointment formulation prepared with 1% Michauxia nuda (root) and Michauxia tchihatchewii (herb) extracts. The results of histopathological evaluation supported the outcome of incision and excision wound models. Moreover, the Michauxia nuda (root) exerted remarkable anti-inflammatory effect. The highest antioxidant activity was observed with the ethyl acetate extract of Michauxia tchihatchewii herb. CONCLUSION The experimental study revealed that Michauxia displays remarkable wound healing and anti-inflammatory and antioxidant activities.

Antioxidant and antimicrobial activities of branches extracts of five Juniperus species from Turkey

Context: Several Juniperus species (Cupressaceae) are utilized in folk medicine in the treatment of infections and skin diseases. Objective: This work was designed to evaluate the antioxidant and antimicrobial potential of methanol and water branches extracts of Juniperus species from Turkey: Juniperus communis L. var. communis (Jcc), Juniperus communis L. var. saxatilis Pall. (Jcs), Juniperus drupacea Labill. (Jd), Juniperus oxycedrus L. subsp. oxycedrus (Joo), Juniperus oxycedrus L. subsp. macrocarpa (Sibth. & Sm.) Ball. (Jom). Materials and methods: Total phenolics, total flavonoids and condensed tannins were spectrophotometrically determined. The antioxidant properties were examined using different in vitro systems. The toxicity was assayed by Artemia salina lethality test. The antimicrobial potential against bacteria and yeasts was evaluated using minimum inhibitory concentration and minimum bactericidal concentration (MIC/MBC) measurements. The effect on bacteria biofilms was tested by microtiter plate assay. Results: Both in the DPPH (1,1-diphenyl-2-picrylhydrazyl) and TBA (thiobarbituric acid) test Jom resulted the most active (IC50 = 0.034 ± 0.002 mg/mL and 0.287 ± 0.166 µg/mL). Joo exhibited the highest reducing power (1.78 ± 0.04 ASE/mL) and Fe2+ chelating activity (IC50 = 0.537 ± 0.006 mg/mL). A positive correlation between primary antioxidant activity and phenolic content was found. The extracts were potentially non-toxic against Artemia salina. They showed the best antimicrobial (MIC = 4.88-30.10 µg/mL) and anti-biofilm activity (60–84%) against S. aureus. Discussion and conclusion: The results give a scientific basis to the traditional utilization of these Juniperus species, also demonstrating their potential as sources of natural antioxidant and antimicrobial compounds.