Citation: Danisman, B.; Cicek, B.; Yildirim, S.; Bolat, I.; Kantar, D.; Golokhvast, K.S.; Nikitovic, D.; Tsatsakis, A.; Taghizadehghalehjoughi, A. Carnosic Acid Ameliorates Indomethacin-Induced Gastric Ulceration in Rats by Alleviating Oxidative Stress and Inflammation. Biomedicines 2023, 11, 829. https://doi.org/10.3390/ biomedicines11030829 Academic Editors: Fabio Altieri, Amirata Saei Dibavar, Jean A. Boutin and Albrecht Piiper Received: 26 January 2023 Revised: 19 February 2023 Accepted: 4 March 2023 Published: 9 March 2023 Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). biomedicines Article Carnosic Acid Ameliorates Indomethacin-Induced Gastric Ulceration in Rats by Alleviating Oxidative Stress and Inflammation Betul Danisman 1 , Betul Cicek 2 , Serkan Yildirim 3 , Ismail Bolat 3 , Deniz Kantar 4 , Kirill S. Golokhvast 5 , Dragana Nikitovic 6, * , Aristidis Tsatsakis 7 and Ali Taghizadehghalehjoughi 8, * 1 Department of Biophysics, Faculty of Medicine, Ataturk University, Erzurum 25240, Turkey 2 Department of Physiology, Faculty of Medicine, Erzincan Binali Yildirim University, Erzincan 24100, Turkey 3 Department of Pathology, Faculty of Veterinary, Atatürk University, Erzurum 25240, Turkey 4 Department of Biophysics, Faculty of Medicine, Akdeniz University, Antalya 07058, Turkey 5 Siberian Federal Scientific Centre of Agrobiotechnology, Centralnaya, Presidium, Krasnoobsk 633501, Russia 6 Laboratory of Histology-Embryology, Medical School, University of Crete, 71003 Heraklion, Greece 7 Department of Forensic Sciences and Toxicology, Faculty of Medicine, University of Crete, 71003 Heraklion, Greece 8 Department of Medical Pharmacology, Faculty of Medicine, Bilecik Seyh Edebali University, Bilecik 11000, Turkey * Correspondence: nikitovic@uoc.gr (D.N.); ali.tgzd@bilecik.edu.tr (A.T.) Abstract: Nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin and indomethacin (IND) are the most commonly prescribed for inflammation or pain. However, widespread use causes several adverse effects, such as gastric ulcers, upper gastric system bleeding, and erosions. Carnosic acid (CA) is an important natural antioxidant found in rosemary (Rosmarinus essentials) and exhibits a protective effect by suppressing oxidative stress and inflammation. This study aimed to investigate the impact of CA on IND-induced gastric ulceration. Wistar male rats received CA (100 mg/kg) or esomeprazole (ESP) (20 mg/kg, standard drug) by oral gavage for 14 days, after that gastric ulceration was induced by oral administration of 100 mg/kg IND. CA pretreatment attenuated both gross morphological lesions and histopathological alterations. CA strongly reduced IND-induced oxidative stress, verified by a decrease in MDA (p < 0.001) and TOS levels (p < 0.05). Furthermore, an IND-dependent increase in CAT (p < 0.001) and GPx (p < 0.01) activities, as well as a reduction in GSH levels (p < 0.01), were ameliorated by CA pretreatment. CA also attenuated inflammatory damage by suppressing IL-1β (p < 0.01), IL-6 (p < 0.01), and TNFα (p < 0.001) production and increasing Nrf2/HO-1 (p < 0.05) expressions. In conclusion, CA shows a gastroprotective effect by reducing oxidative stress and attenuating inflammation. Keywords: indomethacin; gastric ulcer; carnosic acid; inflammation; oxidative stress 1. Introduction Non-steroidal anti-inflammatory drugs (NSAIDs) are widely prescribed for treat- ing pain, fever, and inflammation. However, long-term use of the NSAIDs, such as in- domethacin (IND) or aspirin, can cause gastric ulceration by various mechanisms, including injury through inhibition of prostaglandin (PG) synthesis, reduction in local blood flow, regional irritation, and inhibition of tissue regeneration [1,2]. The pathogenesis of gas- tric ulcerative lesion formation is multifactorial and has not been fully clarified. Even though several synthetic anti-ulcerative drugs are currently available, they can exhibit mild to severe side effects [3]. For example, omeprazole, a proton-pump inhibitor (PPI) that blocks the release of gastric acid, may facilitate Clostridium difficile infection [4], in- duce hypomagnesemia [5], or diminish anticoagulant drug efficiencies such as that of clopidogrel [6]. However, other PPIs, including ilaprazole, were shown not to disturb Biomedicines 2023, 11, 829. https://doi.org/10.3390/biomedicines11030829 https://www.mdpi.com/journal/biomedicines