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Öğe High-fat diet enhances gastric contractility, but abolishes nesfatin-1-induced inhibition of gastric emptying(2021) Özdemir-Kumral, Zarife N.; Koyuncuoğlu, Türkan; Arabacı-Tamer, Sevil; Çilingir-Kaya, Özlem T.; Karagöz Köroğlu, Ayça; Yüksel, Meral; C. Yeğen, BerrakBackground/Aims Gastrointestinal motility changes contribute to development and maintenance of obesity. Nesfatin-1 (NES-1) is involved in central appetite control. The aim is to elucidate effects of NES-1 and high-fat diet (HFD) on gastrointestinal motility and to explore myenteric neuron expressions of tyrosine hydroxylase (TH), vasoactive intestinal peptide (VIP), and neuronal nitric oxide synthase (nNOS) in HFDinduced oxidative injury. Methods Sprague-Dawley rats were fed with normal diet (ND) or HFD. Gastric emptying rate was measured following NES-1 (5 pmol/rat, intracerebroventricular) preceded by subcutaneous injections of glucagon-like peptide 1 (GLP-1), cholecystokinin 1 (CCK-1), and gastrin/CCK-2 receptor antagonists. In carbachol-contracted gastric and ileal strips, contractile changes were recorded by adding NES- 1 (0.3 nmol/L), GLP-1, CCK-1, and gastrin/CCK-2 antagonists. Results Neither HFD nor NES-1 changed methylcellulose emptying, but NES-1 delayed saline emptying in cannulated ND-rats. Inhibitory effect of NES-1 on gastric emptying in ND-rats was reversed by all antagonists, and abolished in HFD-rats. In HFD-rats, carbachol-induced contractility was enhanced in gastric, but inhibited in ileal strips. HFD increased body weight, while serum triglycerides, alanine transaminase, aspartate aminotransferase, glucose, and levels of malondialdehyde, glutathione, myeloperoxidase activity, and luminolchemiluminescence in hepatic, ileal, and adipose tissues were similar in ND- and HFD-rats, but only lucigenin-chemiluminescence was increased in HFD-rats. Vasoactive intestinal peptide (VIP) and TH immunoreactivities were depressed and nNOS immunoreactivity was increased in gastric tissues of HFD-rats, while VIP and TH were enhanced, but nNOS was reduced in their intestines. Conclusions HFD caused mild systemic inflammation, disrupted enteric innervation, enhanced gastric contractility, inhibited ileal contractility, and eliminated inhibitory effect of NES-1 on gastric motility.Öğe Nesfatin-1 ameliorates oxidative brain damage and memory impairment in rats induced with a single acute epileptic seizure(Elsevier, 2022) Arabacı Tamer, Sevil; Koyuncuoğlu, Türkan; Karagöz Köroğlu, Ayça; Akakın, Dilek; Yüksel, Meral; Yeğen, Berrak Ç.Aims: We aimed to investigate putative neuroprotective effects of nesfatin-1 on oxidative brain injury and memory dysfunction induced by a single epileptic seizure and to compare these effects with those of antiepileptic phenytoin. Main methods: Wistar albino rats were randomly divided into a control group and pentylenetetrazole (PTZ)-seizure groups pretreated intraperitoneally (ip) with saline or nesfatin-1 (NES-1; 0.3, 1 or 3 ?g/kg/day) or phenytoin (PHE; 40 mg/kg/day) or PHE + NES-1 (0.3 ?g/kg/day) at 30 min before the single-dose PTZ injection (45 mg/kg; ip). All treatments were repeated at the 24th and 48th h of the provoked epileptic seizure. Passive-avoidance test was performed to assess memory function. The rats were decapitated at the 72nd hour of seizures and brain tissues were analyzed for histopathological changes and for measuring levels of malondialdehyde, glutathione, myeloperoxidase activity and reactive oxygen/nitrogen species. Key findings: In parallel to the effects of phenytoin, NES-1 reduced seizure score, elevated antioxidant glutathione content, depressed generation of nitric oxide and protected against seizure-induced neuronal damage. Additionally, increased malondialdehyde levels and elevated glial fibrillary acidic protein immunoreactivity in the cortex and hippocampus were decreased and memory dysfunction was improved by NES-1. However, NES-1 had no impact on myeloperoxidase activity or production of reactive oxygen species in the brain. Significance: The findings of the present study demonstrate that nesfatin-1 treatment provides neuroprotection against seizure-induced oxidative damage and memory dysfunction by inhibiting reactive nitrogen species and upregulating antioxidant capacity, indicating its potential in alleviating memory deficits and increasing the effectiveness of conventional anti-convulsant therapies. © 2022Öğe Neuroprotective effect of cinnamaldehyde on secondary brain injury after traumatic brain injury in a rat model(Elsevier Inc., 2021) Kuru Bektaşoğlu, Pınar; Koyuncuoğlu, Türkan; Demir, Dilan; Sucu, Gizem; Akakın, Dilek; Peker Eyüboğlu, İrem; Yüksel, Meral; Çelikoğlu, Erhan; Yeğen, Berrak Ç.Objective: The aim of this study was to investigate the possible neuroprotective effects of cinnamaldehyde (CA) on secondary brain injury after traumatic brain injury (TBI) in a rat model. Methods: Rats were randomly divided into 4 groups: control (n = 9), TBI (n = 9), vehicle (0.1% Tween 80; n = 8), and CA (100 mg/kg) (n = 9). TBI was induced by the weight-drop model. In brain tissues, myeloperoxidase activity and the levels of luminol-enhanced and lucigenin-enhanced chemiluminescence were measured. Interleukin 1?, interleukin 6, tumor necrosis factor ?, tumor growth factor ?, caspase-3, and cleaved caspase-3 were evaluated with an enzyme-linked immunosorbent assay method. Brain injury was histopathologically graded after hematoxylin-eosin staining. Y-maze and novel object recognition tests were performed before TBI and within 24 hours of TBI. Results: Higher myeloperoxidase activity levels in the TBI group (P < 0.001) were suppressed in the CA group (P < 0.05). Luminol-enhanced and lucigenin-enhanced chemiluminescence, which were increased in the TBI group (P < 0.001, for both), were decreased in the group that received CA treatment (P < 0.001 for both). Compared with the increased histologic damage scores in the cerebral cortex and dentate gyrus of the TBI group (P < 0.001), scores of the CA group were lower (P < 0.001). Decreased number of entries and spontaneous alternation percentage in the Y-maze test of the TBI group (P < 0.05 and P < 0.01, respectively) were not evident in the CA group. Conclusions: CA has shown neuroprotective effects by limiting neutrophil recruitment, suppressing reactive oxygen species and reducing histologic damage and acute hippocampal dysfunction.Öğe Possible anti-inflammatory, antioxidant, and neuroprotective effects of apigenin in the setting of mild traumatic brain injury: an investigation(Taylor and Francis Ltd., 2022) Kuru Bektaşoğlu, Pınar; Demir, Dilan; Koyuncuoğlu, Türkan; Yüksel, Meral; Peker Eyüboğlu, İrem; Karagöz Köroğlu, Ayça; Akakın, Dilek; Yıldırım, Alper; Çelikoğlu, Erhan; Gürer, BoraObjective: Apigenin is a plant flavone proven with biological properties such as anti-inflammatory, antioxidant, and antimicrobial effects. This study, it was aimed to examine the possible anti-inflammatory, antioxidant, and neuroprotective effects of apigenin in the setting of the mild traumatic brain injury (TBI) model. Methods: Wistar albino male rats were randomly assigned to groups: control (n = 9), TBI (n = 9), TBI + vehicle (n = 8), and TBI + apigenin (20 and 40 mg/kg, immediately after trauma; n = 6 and n = 7). TBI was performed by dropping a 300 g weight from a height of 1 m onto the skull under anesthesia. Neurological examination and tail suspension tests were applied before and 24 h after trauma, as well as Y-maze and object recognition tests, after that rats were decapitated. In brain tissue, luminol- and lucigenin-enhanced chemiluminescence levels and cytokine ELISA levels were measured. Histological damage was scored. Data were analyzed with one-way ANOVA. Results: After TBI, luminol (p <.001) and lucigenin (p <.001) levels increased, and luminol and lucigenin levels decreased with apigenin treatments (p <.01–.001). The tail suspension test score increased with trauma (p <.01). According to the pre-traumatic values, the number of entrances to the arms (p <.01) in the Y-maze decreased after trauma (p <.01). In the object recognition test, discrimination (p <.05) and recognition indexes (p <.05) decreased with trauma. There was no significant difference among trauma apigenin groups in behavioral tests. Interleukin (IL)-10 levels, one of the anti-inflammatory cytokines, decreased with trauma (p <.05), and increased with 20 and 40 mg apigenin treatment (p <.001 and p <.01, respectively). The histological damage score in the cortex was decreased in the apigenin 20 mg treatment group significantly (p <.05), but the decrease observed in the apigenin 40 mg group was not significant. Conclusion: The results of this study revealed that apigenin 20 and 40 mg treatment may have neuroprotective effects in mild TBI via decreasing the level of luminol and lucigenin and increasing the IL-10 levels. Additionally, apigenin 20 mg treatment ameliorated the trauma-induced cortical tissue damage.
