title: Protective effect of hydroalcoholic olive leaf extract on experimental model of colitis in rat: involvement of nitrergic and opioidergic systems.
abstract: The aim of the present study is to investigate the possible protective effect of dry olive leaf extract (OLE) against acetic acid-induced ulcerative colitis in rats, as well as the probable modulatory effect of nitrergic and opioidergic systems on this protective impact. Olive leaf extract was administered (250, 500 and 750 mg/kg) orally for two successive days, starting from the colitis induction. To assess the involvement of nitrergic and opioidergic systems in the possible protective effect of OLE, L-NG-Nitroarginine Methyl Ester (10 mg/kg) and naltrexone (5 mg/kg) intraperitoneal (i.p.) were applied 30 min before administration of the extract for two successive days, respectively. Colonic status was investigated 48 h following induction through macroscopic, histological and biochemical analyses. Olive leaf extract dose-dependently attenuated acetic acid-provoked chronic intestinal inflammation. The extract significantly reduces the severity of the ulcerative lesions and ameliorated macroscopic and microscopic scores. These observations were accompanied by a significant reduction in the elevated amounts of TNF-α and interlukin-2 markers. Moreover, both systems blockage reversed protective effects of OLE in the rat inflammatory bowel disease model. These finding demonstrated, for the first time, a possible role for nitrergic and opioidergic systems in the aforementioned protective effect, and the extract probably exerted its impact increasing nitric oxide and opioid tones.
authors.affiliation: Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran; Brain and Spinal Injury Research Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Nahid
authors.initials: N
authors.lastname: Fakhraei
authors.forename: Amir Hossein
authors.initials: AH
authors.lastname: Abdolghaffari
authors.forename: Bahram
authors.initials: B
authors.lastname: Delfan
authors.forename: Ata
authors.initials: A
authors.lastname: Abbasi
authors.forename: Nastaran
authors.initials: N
authors.lastname: Rahimi
authors.forename: Azadeh
authors.initials: A
authors.lastname: Khansari
authors.forename: Reza
authors.initials: R
authors.lastname: Rahimian
authors.forename: Ahmad Reza
authors.initials: AR
authors.lastname: Dehpour
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology; D003093:Colitis, Ulcerative / Q000139:chemically induced / Q000188:drug therapy*; D003106:Colon / Q000187:drug effects* / Q000473:pathology; D007376:Interleukin-2 / Q000378:metabolism; D008297:Male; D031658:Olea / Q000737:chemistry*; D010936:Plant Extracts / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry; D051381:Rats; D017208:Rats, Wistar; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D000893:Anti-Inflammatory Agents; D007376:Interleukin-2; D010936:Plant Extracts; D014409:Tumor Necrosis Factor-alpha
keywords: acetic acid-induced colitis; inflammatory bowel disease (IBD); interlukin-2 (IL-2); nitrergic and opioidergic systems; olive leaf extract (OLE); tumour necrosis factor-α (TNF-α)