Murat Bakir

The effects of Cetraria islandica and Pseudevernia furfuracea extracts in normal and diabetic rats

Lichens are symbiotic organisms composed of a fungus joined to a photosynthesizing partner that can be either an alga or a cyanobacterium. They can be used as a novel bioresource for natural antioxidants. However, there is also a need for further studies to validate the lichens used in medicinal remedies. This study covers a previously unrecognized effects of Cetraria islandica (CIAE) and Pseudevernia furfuracea (PFAE) in streptozotocin (STZ)-induced diabetes. In experimental design, control or diabetic rats were either untreated or treated with aqueous lichen extracts (250–500 mg/kg/day) for 2 weeks starting at 72 h after STZ injection. On day 14, animals were anesthetized, metabolic and biochemical parameters were appreciated between control and treatment groups. The histopathology of kidney was examined using four different staining methods: hematoxylin–eosin (H&E), periodic acid-Schiff (PAS), Masson trichrome and Congo red. Our experimental data showed that increasing doses of CIAE and PFAE did not have any detrimental effects on the studied parameters and the malondialdehyde level of kidney. CIAE extract showed prominent results compared to doses of PFAE extract for antioxidant capacity. However, the protective effect of CIAE extract was inadequate on diabetes-induced disorders and kidney damages. Moreover, animals subjected to diabetes mellitus (DM) therapy did not benefit unfortunately from the usage of increasing lichen doses due to their unchanged antioxidant activity to tissue. The results obtained in present study suggested that CIAE and PFAE are safe but the power of these is limited because of the intensive oxidative stress in kidney of type 1 diabetic rats. It is also implied that CIAE extract is especially suitable for different administration routes in DM.

Impact of high-dose oleuropein on cisplatin-induced oxidative stress, genotoxicity and pathological changes in rat stomach and lung

Abstract The current systemic treatments of the various solid tumors involve Cisplatin (CIS)-based chemotherapy. Due to its cytotoxicity, this approach is limited. Moreover, the safety of CIS is only discussed especially in breast and stomach cancers. Therefore, we, for the first time, explored the restorative efficacy of oleuropein (OLE), in stomach and lung injuries induced by CIS. Sprague-Dawley rats were divided into eight groups: control CIS, OLE and CIS + OLE. Single dose of (7 mg/kg) CIS was administered intraperitoneally to CIS and CIS + OLE groups. After 24 h, 50, 100 and 200 mg/kg OLE was given for three consecutive days to OLE and CIS + OLE groups. The 8-OH-dG, total oxidative/antioxidant status (TOS/TAS) and malondialdehyde (MDA) levels were evaluated and histopathological analyses were performed on the studied tissues. The results indicated that CIS significantly increased 8-OH-dG, MDA and TOS levels and caused severe tissue damages. However, high dose of OLE induced a significant decrease in the 8-OH-dG, MDA levels, an increase in TAS levels and it restores CIS-induced tissue damages. We hope that the results of this study will provide an impetus for future studies on novel therapeutic strategies including the protective use of oleuropein in gastric and lung cancers due to chemotherapy.

The Efficacy of Carvacrol on Renal Damage in Rats with Acute Pancreatitis

Abstract The carvacrol is thought to promote optimal health via its antioxidant and free radical scavenging effects. The aim of our present study was to investigate the efficacy of carvacrol on the development of kidney injury in acute pancreatitis model (AP) induced by cerulein and to explore the underlying mechanism. The rats were randomised into groups to receive (I) no therapy; (II.) 50 µg/kg cerulein at 1-h intervals by four intraperitonally injection (i.p.); (III) 50, 100 and 200 mg/kg carvacrol by one i.p.; and (IV) cerulein+carvacrol after 2 h of cerulein injection. 12 h later, serum was provided to assess the blood urea nitrogen (BUN), creatinine (CRE) and uric acid (UA) values. Also, renal tissues were obtained for histological and biochemical measurements. Kidney oxidative stress markers were evaluated by changes in the amount of lipid peroxides measured as malondialdehyde (MDA) and changes in tissue antioxidant enzyme levels, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-PX). Histopathological examination was performed using scoring systems. We found that the increasing doses of carvacrol decreased pancreatitis-induced MDA levels. Moreover, the renal SOD, CAT and GSH-Px activities in the AP+carvacrol group were higher than that of the rats in the AP group. In the treatment groups, the BUN, CRE and UA were reduced. Besides, necrosis, coagulation and inflammation in the kidney were alleviated (p < 0.05). Finally, the magnitude of the protective effect on kidney is certain, and 200 mg/kg carvacrol is an effective theraphy for oxidative stress caused by AP.