N. Ülkü Karabay Yavaşoğlu
Ege University
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Featured researches published by N. Ülkü Karabay Yavaşoğlu.
International Journal of Pharmaceutics | 2011
Neslihan Üstündağ Okur; Şebnem Apaydın; N. Ülkü Karabay Yavaşoğlu; Altug Yavasoglu; H. Yeşim Karasulu
The aim of this study was to evaluate the potential application of microemulsions as a transdermal drug delivery for naproxen (Np). The pseudo-ternary phase diagrams were developed for microemulsions composed of isopropyl myristate, Span 80, Labrafil M, Labrasol, and Cremophor EL, ethanol and isopropyl alcohol and 0.5N sodium hydroxide. The final concentration of Np in microemulsion systems was 10% (w/w). The microemulsions were characterised by conductivity, droplet size, viscosity and pH. Moreover, in vitro permeability studies were performed using diffusion cells from rat skin. The permeation rates of Np from microemulsions (M1(Np) and M2(Np)) were higher than the commercial (C) gel formulation. The paw oedema test was performed in rats to evaluate the anti-inflammatory activity of Np. The volume increase in paw oedema after 6hr was 0.71±0.46% with M2(Np), whereas M1(Np) and C exhibited 6.48±2.71% and 14.97±3.15% increases in oedema, respectively. Additionally, a significant analgesic effect was detected in the hot plate and tail-flick tests for all test microemulsion and C formulations when compared with the control. Histopathological examination of the treated skin was performed to investigate changes in skin morphology. In conclusion, the microemulsion formulations, especially the M2(Np) formulation, may be used as an effective alternative for the transdermal delivery of Np.
Experimental and Toxicologic Pathology | 2008
Altug Yavasoglu; M. Ali Karaaslan; Yiğit Uyanıkgil; Ferah Sayim; Utku Ateş; N. Ülkü Karabay Yavaşoğlu
Anatoxin-a, a potent neurotoxin, is one of a number of toxins produced by cyanobacteria especially some strains of Anabaena. Toxic cyanobacteria are found worldwide in inland and coastal water environments. The present study was performed to evaluate the toxicity of anatoxin-a on testes and sperm counts of male mice. The animals of the treatment groups were administered with 50, 100 and 150microg/kg/day anatoxin-a for seven consecutive days by intraperitoneal (i.p.) route. Although there were no significant changes in body weight gain, and absolute and relative testes weights, absolute and relative weights of cauda epididymis reduced significantly in the 100 and 150microg/kg groups when compared with control group. The number of sperm count in cauda epididymis was reduced dose dependently in all treatment groups compared with control animals. Anatoxin-a caused dose-dependent histopathological changes in the testes of mice such as degenerations in seminiferous tubules, intercellular disassociation of spermatogenetic cell lines, sloughing of germ cells into tubular lumen, vacuolisation in Sertoli cells and loss of germ cells. The epithelial thickness of seminiferous tubules decreased significantly in all treatment groups in a dose-dependent manner.
European Journal of Medicinal Chemistry | 2011
Hayati Türkmen; Nur Ceyhan; N. Ülkü Karabay Yavaşoğlu; Guven Ozdemir; Bekir Çetinkaya
Variously substituted benzyl bromides were employed to quaternize hexahydrobenzylimidazo[1,5-a]pyridine (A) and the resulting bromides (1-11) were evaluated for their in vitro antimicrobial activity against 10 pathogenic microorganisms: Staphylococcus aureus, Staphylococcus epidermidis, Bacillus cereus, Micrococcus luteus, Proteus vulgaris, Escherichia coli, Salmonella typhimurium, Klebsiella pneumonia, Candida albicans and Candida krusei. Antimicrobial activities were surprisingly high (MIC: 0.78-400 μg/mL) and the sensitivity of the salts tested has been found to depend strongly both on the benzyl substituents and the microorganisms used. However, the correlation observed between antimicrobial activity and calculated partition coefficient (ClogP) was poor. Acute toxicity assessment of these salts showed LD(50) of 757-2000 mg/kg, after oral administration in mice in 24h.
Pharmaceutical Biology | 2006
N. Ülkü Karabay Yavaşoğlu; Sura Baykan; Bintuğ Öztürk; Sebnem Apaydin; Isιk Tuglular
Abstract The aim of this study was to investigate the antinociceptive and anti-inflammatory activities of the essential oil of Satureja thymbra. L. (Lamiaceae). Antinociceptive activity of the essential oil was measured by the formalin test in mice and by the light tail-flick and hot-plate methods in rats. The paw-edema test was performed in rats to evaluate the anti-inflammatory effect of the essential oil. Motor coordination was assessed with a rotarod apparatus. Although the essential oil produced an antinociceptive effect during both the early (50 and 100 mg kg−1) and late phases (25, 50, and 100 mg kg−1) of the formalin test, it did not exert any significant antinociceptive and anti-inflammatory effects in tail-flick and paw-edema tests, respectively. In addition, a significant antinociceptive effect was detected in the hot-plate test (100 and 200 mg kg−1). No significant change was detected in sensory motor performance. In conclusion, S. thymbra. L. essential oil does not exert any anti-inflammatory effect while it may have central analgesic activity in mice and rats.
Environmental Toxicology | 2014
N. Ülkü Karabay Yavaşoğlu; Çinel Köksal; Melih Dağdeviren; Huseyin Aktug; Altug Yavasoglu
Phthalates are esters of phthalic acid and are mainly used as plasticizers in a wide variety of products and applications. There is no information on butyl cyclohexyl phthalate (BCP) toxicity. This study was performed to evaluate the histopathological effects and to determine oxidative stress inducing potential in liver by subacute exposure of BCP. The animals of the treatment groups were orally administered 100, 200, and 400 mg/kg/day BCP for 5 consecutive days per week during 28 days. As a result, no significant changes were observed in body weight gains, and absolute and relative liver weights of liver of BCP treated mice, when compared with control group. Although the degree of lipid peroxidation in the liver tissue of all BCP exposure groups were significantly higher than those of the control (p < 0.01), SOD and CAT activities in liver tissue of mice of 200 and 400 mg/kg exposure groups were significantly lower than those of the controls (p < 0.01). Moreover, BCP caused dose‐dependent histological changes in the liver of mice such as congestions in vena centralis, an enlargement of the sinusoids, degeneration in hepatocytes, vacuole formations and presence of lipid droplets in hepatocytes, eosinophilic cytoplasm. While iNOS immunoreactivity was increased in all treatment groups, Type IV collagen and Connexin 43 immunoreactivities were decreased in all treatment groups compared with the control group. Significant decrease was observed in the number of TUNEL‐positive liver cells of BCP treated mice. These results suggested that BCP exposure induces oxidative stress in liver and exposure of BCP during long time period could lead to hepatocarcinogenesis.
Bulletin of Environmental Contamination and Toxicology | 2017
Dilara Özkan; Melih Dağdeviren; Selma Katalay; Adem Güner; N. Ülkü Karabay Yavaşoğlu
In this study, sublethal effects on the Mediterranean mussels (Mytilus galloprovincialis L.) collected from the Aegean coast of Turkey were determined. Enzymes such as glutathione-S-transferase (GST), superoxide dismutase (SOD), catalase (CAT), and acetylcholinesterase (AChE), metallothionein (MT) mRNA expressions, thiobarbituric acid reactive substances (TBARS) contents, determination of 14 heavy metals and micronucleus frequency were selected as multibiomarkers. Results show that heavy metals and an increase in the level of MT gene expression have been determined in tissues of mussels collected from all stations. The GST, SOD and CAT enzymes were increased in mussels of Aliaga and Old Foca, compared to the mussels of Urla, while it was showed inhibition at AChE levels. Extensive LP is determined on mussels of Aliaga. It was determined that mussels in Aliaga region have exposed more oxidative stress than Old Foca and Urla. These biomarkers were carried out for the first time in these stations to assess environmental quality.
Marine Pollution Bulletin | 2016
Altug Yavasoglu; Dilara Özkan; Adem Güner; Selma Katalay; Fatih Oltulu; N. Ülkü Karabay Yavaşoğlu
Marine bivalve mussels, especially Mytilus species are an earlywarning system used for determining of damage caused by the various aquatic pollutions. In the present study, Mytilus galloprovincialis L. (black mussel) have been utilised as a biomonitoring organism to reveal environmental pollution in the Aliaga, Foca and Urla where located along the Izmir Coast of Turkey. Mussels were collected at these areas and gill and hepatopancreas (digestive gland) tissues were excised. mRNA expressions of initiator (caspase-2 and -8) and executioner (caspase -3/7-1, -3/7-2, -3/7-3 and -3/7-4) caspases of mussels tissues in areas exposed to pollution agent have been observed. TUNEL immunoreactivity in paralel to histopathological changes in both Aliaga and Foca areas were compared with Urla. This study is the first report to reveal the pollution with apoptotic expression on mussels in the coast of Turkey.
Pharmaceutical Biology | 2014
Sura Baykan Erel; Serdar Demir; Ayse Nalbantsoy; Petek Ballar; Shabana I. Khan; N. Ülkü Karabay Yavaşoğlu; Canan Karaalp
Abstract Context: Centaurea L. (Asteraceae) species used as herbal remedies in Turkish traditional medicine have shown several biological properties. Objective: Extracts obtained from the aerial parts of Centaurea aphrodisea Boiss., Centaurea athoa DC., Centaurea hyalolepis Boiss., Centaurea iberica Trev. and Centaurea polyclada DC. were evaluated for their antioxidant, cytotoxic and anti-inflammatory activities. Materials and methods: Extracts of Centaurea species were tested for their antioxidant activity in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) screening assays and for in vitro anti-inflammatory activity by Nf-κB and iNOS inhibition assays. The extracts were tested for their in vitro cytotoxicities against a panel of human solid tumor cell lines (SK-MEL: malignant melanoma, KB: oral epidermal carcinoma, BT-549: breast ductal carcinoma and SK-OV-3: ovary carcinoma) as well as non-cancerous kidney fibroblast (Vero) and kidney epithelial cells (LLC-PK1) by Neutral Red assay. In vivo anti-inflammatory activity of C. athoa was evaluated by the carrageenan-induced paw edema test in rats. Results: Antioxidant activities were observed for methanol extracts of plants. C. polyclada had the strongest effect on BT-549, KB and SK-OV-3 cell lines (30, 33 and 47 µg/ml, respectively). Nf-κB inhibition of chloroform extract of C. athoa was determined equivalent to positive control parthenolide (IC50: 6 µg/ml). This extract also showed anti-inflammatory activity by the carrageenan-induced paw edema test in rats, in all hours at a dose of 50 mg/kg compared to the control group. Discussion and conclusion: C. athoa is suggested to be a potential source of lead compounds for inflammatory diseases due to the significant in vitro and in vivo anti-inflammatory results.
Natural Product Research | 2015
Sadi Kızılşahin; Ayse Nalbantsoy; N. Ülkü Karabay Yavaşoğlu
The aim of this study was to determine in vitro synergistic efficacy of conjugated linoleic acid (CLA), oleic acid (OLA), safflower oil and taxol (Tax) cytotoxicity on human prostate cancer (PC3) cell line. To determine synergistic efficacy of oil combinations, PC3 treated with different doses of compounds alone and combined with 10 μg/mL Tax. The MTT results indicated that OLA–Tax combinations exhibited cytotoxicity against PC3 at doses of 30 nM+10 μg-Tax, 15 nM+5 μg-Tax and 7.5 nM+2.5 μg-Tax. The treatment of OLA or Tax did not show significant inhibition on PC3, while OLA–Tax combinations showed effective cytotoxicity at treated doses. CLA–Tax combinations demonstrated the same effect on PC3 as combined form with 45.72% versus the alone form as 74.51% viability. Cytotoxic synergy between Tax, OLA and CLA shows enhanced cytotoxicity on PC3 which might be used in the therapy of prostate cancer.
Pharmaceutical Biology | 2012
Iskender Ince; Hüsniye Kayalar; Gozde Elgin; Çinel Köksal; N. Ülkü Karabay Yavaşoğlu
Context: Polyherbal formulations containing different plants are used for the treatment of various diseases. Romix® powder is a polyherbal formulation consisting of 14 traditionally used herbs and is used as a food supplement. There is no information about pharmaceutical activities of Romix®. Objective: This study determined the total phenolic and total flavonoid content, and investigated the antioxidant and anti-inflammatory activities and acute toxicity of Romix®. Material and methods: The total phenolics in the extracts were determined colorimetrically by using the Folin-Ciocalteu reagent. The total flavonoid content of the extracts was evaluated by a spectrophotometric method. The quercetin content of the extract was analyzed using the high-performance liquid chromatography (HPLC) method. Antioxidant activity of the extracts was determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity assays. The anti-inflammatory activity was evaluated by the carrageenan-induced paw edema test in the rat. Results: The flavonoid and phenolics contents of Romix® were 50.58 and 265.83 mg/g in ethanol extract and 18.60 and 222.50 mg/g in water extract, respectively. Total quercetin content of Romix® was determined as 2.857 mg/g. Antioxidant activity results showed that ethanol extract in 1 mg/mL concentration (4.49775 µg/mL) had moderate antioxidant activity than water extract in the same concentration (4.28191 µg/mL). Intraperitoneal administration of 25 mg/kg Romix® extract exhibited anti-inflammatory activity and inhibited paw swelling at 1, 2, 3, 4, 5 and 6 h in rats with no acute toxicity. Conclusion: These findings suggest that Romix® due to its antioxidant and anti-inflammatory activities may be useful in the prevention or treatment of aging-related and inflammatory diseases.