Özçelik, Azime Berna; Özdemir, Zeynep; Sari, Suat; Utku, Semra; Uysal, Mehtap

Background: The pyridazinone nucleus has been incorporated into a wide variety of therapeutically interesting molecules to transform them into better drugs. Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) are known to be serine hydrolase enzymes responsible for the hydrolysis of acetylcholine (ACh). Inhibition of cholinesterases is an effective method to curb Alzheimer's disease. Here, we prepared 12 new 6-substituted-3(2H)-pyridazinone-2-acetyl-2-(nonsubstituted/4-substituted benzenesulfonohydrazide) derivatives and evaluated their inhibitory effects on AChE/BChE in pursuit of potent dual inhibitors for Alzheirmer's Disease. We also tried to get insights into binding interactions of the synthesized compounds in the active site of both enzymes by using molecular docking approach. Method: We obtained our compounds by the reaction of various substituted/nonsubstituted benzenesulfonic acid derivatives with 6-substitutedphenyl-3(2H)-pyridazinone-2-yl acetohydrazide and determined their anticholinesterase activities according to the Ellman's method. Molecular docking studies were done using Glide and the results were evaluated on Maestro (Schrödinger, LLC, New York, NY, 2019). Results: The title compounds showed moderate inhibition at 100 μg/ml against both enzymes, yet with better activity against BChE. Compound VI2a emerged as a dual inhibitor with 25.02% and 51.70% inhibition against AChE and BChE, respectively. Conclusion: This study supports that novel pyridazinone derivates may be used for the development of new BChE inhibitory agents. It was less potent than the reference drugs, yet promising for further modifications as a lead. The ability of the compounds to adopt energetically more favourable conformations and to engage in more key interactions in the ECBChE active gorge explains their better activity profile against ECBChE.

Gürbüzel, Mehmet; Sayar, Ilyas; Cankaya, Murat; Gürbüzel, Ahmet; Demirtas, Levent; Bakirci, Eftal Murat; Capoglu, Ilyas

Background In this study, the effects of levosimendan used in the treatment of acute congestive heart failure upon pulmonary fibrosis in rats induced with bleomycin (BL) were analyzed. Methods A total of 33 male Sprague-Dawley type rats were categorized into five groups randomly. About 2.5 U/kg BL was intratracheally administered to the rats in the BL, BL + L1, BL + L2, and BL + L3 groups, and 0.9% saline was intratracheally administered at the same rate to the control group. 0.3, 1, and 3 mg/kg levosimendan was intraperitoneally administered to the BL + L1, BL + L2, and BL + L3 groups, respectively. Blood and tissue samples were taken from the rats euthanized to determine the changes in erythrocyte enzyme activities and to conduct histopathological evaluations after 14 days. With values between 0 and 3, histopathological scoring damage was assessed by the presence of inflammation and fibrosis in a semiquantitative manner. Results Compared with those in the C group, glutathione reductase (GR) and Catalase (CAT) enzymes decreased in the BL group; compared with that in the BL group, GR increased in the BL + L1 and BL + L3 groups, 6-phosphogluconate dehydrogenase (6PGD) increased in the BL + L3 group, and CAT increased in the BL + L2 and BL + L3 groups (p < 0.05). In the histopathological evaluation, fibrosis occurred in all rats in the BL group, and tissue damage was noticed to be generally less in the BL + L1, BL + L2, and BL + L3 groups (p < 0.001). Conclusions The results obtained from biochemical and histopathological evaluations indicate that levosimendan had an anti-fibrotic effect without a dose-dependent response on pulmonary fibrosis.

Demiryilmaz, Ismail; Turan, Mehmet Ibrahim; Kisaoglu, Abdullah; Gulapoglu, Mine; Yilmaz, Ismayil; Suleyman, Halis

Background Nimesulide is a pharmacological agent and selective COX-2 inhibitor. It has anti-inflammatory, analgesic and antipyretic properties. The purpose of this study was to investigate the effect of nimesulide on oxidant/antioxidant, DNA mutation and COX-1/COX-2 activities in rat liver tissue with induced ischemia/reperfusion (I/R). Methods Before the experiment, rats were divided into four groups; liver ischemia/reperfusion (LIR), 50 mg/kg nimesulide + liver ischemia/reperfusion (NLIR50), 100 mg/kg nimesulide + liver ischemia/reperfusion (NLIR100) and a control group to be given a sham operation (SG). Malondialdehyde (MDA), total glutathione (GSH) levels and myeloperoxidase (MPO), COX-1/COX-2 enzyme activities and DNA damage product level results from liver tissues and serum AST and ALT levels were determined. The data obtained were compared with the results from the liver ischemia/reperfusion and sham operation groups. Results MDA levels, MPO and COX-2 activities and products of DNA injury were significantly lower in the groups given nimesulide, and particularly the NLIR100 group, compared to the LIR group (p < 0.05), while tGSH levels were significantly higher (p < 0.05). There was no significant difference between the NLIR50 and NLIR100 groups and the LIR group in terms of COX-1 levels (p > 0.05). AST and ALT levels were significantly lower in the other groups compared to the LIR group (p < 0.05). Conclusions Nimesulide at 100 mg/kg prevented oxidative liver damage induced with I/R significantly better than at a dose of 50 mg/kg. These experimental findings indicate that nimesulide may be useful in the treatment of hepatic I/R damage.