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    Determination of Antioxidant, Anticholinesterase, Tyrosinase Inhibitory Activities and Fatty Acid Profiles of 10 Anatolian Klasea Cass. Species
    (Acg Publications, 2016) Tel, Gulsen; Dogan, Bekir; Erol, Ebru; Ozturk, Mehmet; Nadeem, Said; Ullah, Zain; Duru, Mehmet Emin
    In search of new natural fatty acid sources, extract of 10 different Turkish Klasea species were studies. Fatty acids of Klasea species were studied by GC and GC-MSD. Oleic acid (4.8-45.8%), palmitic acid (15.6-51.8%), linoleic acid (0.3-45.5%), palmitoleic acid (0.8-28.4%) and linolenic acid (15.6-34.6%) were the main fatty acids elucidated. All extracts were also subjected to acetylcholinesterase, butyrylcholinesterase, tyrosinase, beta-carotene-linoleic acid, DPPH center dot scavenging, CUPRAC and ferrous ion-chelating ability activities. Total flavonoid and phenolic contents were determined as quercetin and pyrocatechol equivalents. All extracts showed significant antioxidant activity in all tests, except hexane extracts of K. serratuloides and K. cerinthifolia that showed weak inhibition against BChE and AChE. The hexane extract of K. coriaceae and methanol extract of K. serratuloides exhibited notable tyrosinase inhibitory activity.
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    Fatty Acid Composition, Antioxidant, Anticholinesterase and Tyrosinase Inhibitory Activities of Four Serratula Species from Anatolia
    (Acg Publications, 2013) Tel, Gulsen; Ozturk, Mehmet; Duru, Mehmet Emin; Dogan, Bekir; Harmandar, Mansur
    Serratula L. (Astareceae) rich in ecdysteroid, phytoecdysteroids and flavonoids some have various biological activities including antibacterial and antitumor. The fatty acid profiles of four Serratula species were investigated by using GC and GC-MS techniques. Palmitic, oleic, linoleic and linolenic acids were found to be the main fatty acids. The unsaturation percentage was between 27.24-50.47%. The antioxidant activity of the extracts was determined by using four complementary tests; namely, beta-carotene-linoleic acid, DPPH center dot scavenging, CUPRAC and ferrous-ions chelating assays. The methanol extract of S. lasiocephala showed the highest activity in beta-carotene-linoleic acid, DPPH center dot scavenging and CUPRAC assays, while the hexane extract of S. radiata exhibited the best metal chelating activity. In addition, total phenolic and total flavonoid contents in the extracts were determined as pyrocatechol and quercetin equivalents, respectively. The in vitro anticholinesterase activity of extracts were tested against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) which are the key enzymes taking place in pathogenesis of Alzheimer's disease. Besides, the extracts were tested in vitro against tyrosinase enzyme which is associated with melanin hyperpigmentation. Except the hexane extracts of S. radiata and S. lasiocephala, the extracts showed moderate inhibition against AChE and BChE, while the only hexane extract of S. erucifolia and methanol extract of S. radiata exhibited tyrosinase inhibitory activity.
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    The usefulness of quantitatively assessing temporomandibular joint disk stiffness with shear wave elastography in adolescents with bruxism
    (Elsevier Science Inc, 2022) Ozturk, Mehmet; Erdur, Emire Aybuke; Dag, Nurullah; Erdur, Omer
    Objective. The objectives of this study were to quantitatively measure temporomandibular joint (TMJ) disk stiffness in adolescents with bruxism using shear wave elastography (SWE) and to examine the relationship between elastography values, patient age, and duration of bruxism.Study Design. This prospective study evaluated 120 TMJ disks of 60 adolescents (30 patients with bruxism and 30 controls). The stiffness of the anterior, intermediate, and posterior parts of the disk was measured. The patient and control groups' respective quantitative SWE values of elasticity (kilopascals [kPa]) and velocity (meters/second [m/s]) were compared.Results. The elasticity and velocity values of the anterior and intermediate parts were significantly higher in the patients than in the controls (P < .013), with no significant difference in the size of the joint space (P = .886). A receiver operating characteristic anal-ysis resulted in sensitivity for the anterior part of 0.80 for kPa and 0.83 for m/s, with specificity of 0.57 (kPa) and 0.60 (m/s). For the intermediate part, the sensitivity was 0.80 for kPa and 0.86 for m/s, with specificity of 0.64 (kPa) and 0.57 (m/s). No correla-tions were found between the SWE values and patient age (P > .098) or duration of bruxism (P > .134).Conclusions. SWE may be useful in the evaluation of TMJ disk stiffness in patients with bruxism. (Oral Surg Oral Med Oral Pathol Oral Radiol 2022;134:492-499)