title: Analgesic and antispasmodic activities of 2-(2-nitro-phenyl)-1H-benzimidazole 5-carboxylic acid: evidence for the importance of the 2-(o-substituted phenyl) group.
abstract: Benzimidazole 5-carboxylic acid derivatives were investigated for analgesic activity in this study. Of the benzimidazole compounds tested, 2-(2-nitro-phenyl)-1H-benzimidazole 5-carboxylic acid showed remarkable naloxone sensitive analgesic activity in the tail clamp but not in the tail immersion analgesia tests. This centrally active compound showed antispasmodic activity only on KCl induced contractions of isolated rat ileum and not on acetylcholine induced contractions. Acute toxicity of the compounds were >100 mg/kg i.p. mice. It was concluded that substitution of the 2(o-phenyl) by nitro- but not by chloro- or methoxy groups is important for naloxone sensititive analgesic activity of benzimidazole compounds and it was hypothetized that new imidazole compounds having a 2-(o-substituted phenyl) moiety needs to be investigated.
authors.affiliation: Department of Pharmacology, Faculty of Pharmacy, Anadolu University, Eskisehir, Turkey. saydin@anadolu.edu.tr
authors.forename: S
authors.initials: S
authors.lastname: Aydin
authors.forename: R
authors.initials: R
authors.lastname: Beis
authors.forename: O D
authors.initials: OD
authors.lastname: Can
mesh_terms: D018712:Analgesics, Non-Narcotic / Q000138:chemical synthesis* / Q000494:pharmacology* / Q000633:toxicity; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D001562:Benzimidazoles / Q000138:chemical synthesis* / Q000494:pharmacology*; D002264:Carboxylic Acids / Q000138:chemical synthesis* / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical; D005260:Female; D007101:Immersion / Q000009:adverse effects; D066298:In Vitro Techniques; D007928:Lethal Dose 50; D008297:Male; D051379:Mice; D010147:Pain Measurement / Q000187:drug effects; D010276:Parasympatholytics / Q000138:chemical synthesis* / Q000494:pharmacology* / Q000633:toxicity; D010812:Physical Stimulation; D013329:Structure-Activity Relationship
chemical_list: C475906:2-(2-nitro-phenyl)-1H-benzimidazole 5-carboxylic acid; D018712:Analgesics, Non-Narcotic; D001562:Benzimidazoles; D002264:Carboxylic Acids; D010276:Parasympatholytics