title: Antinociceptive activity of Tilia americana var. mexicana inflorescences and quercetin in the formalin test and in an arthritic pain model in rats.
abstract: Tilia species are well known around the world for their properties in traditional medicine. Antinociceptive activity of hexane, methanol and aqueous extracts from Tilia americana var. mexicana inflorescences was evaluated in the pain-induced functional impairment model in rats (PIFIR). A preliminar 300 mg/kg dosage of aqueous extracts i.p., but not the same dose of methanol or hexane extract, produced an antinociceptive response in rats similar to that of tramadol (17.8 mg/kg i.p.). A dose-response curve from aqueous extract allowed the determination of ED(50) = 364.97 mg/kg in comparison to ED(50) = 10.35 mg/kg for tramadol in this model. A previous HPLC-DAD analysis corroborated by an HPLC-MS technique in this study demonstrated the flavonoid composition in this Tilia aqueous extract revealing the presence of glycosides mainly derived from quercetin. Thus, Tilia aqueous extract and quercetin were tested at 30 and/or 100 mg/kg dosages i.p. in the PIFIR and formalin models producing a significant and dose-dependent antinociceptive response resembling that produced by a total and a partial agonist of 5-HT(1A) receptors like 8-OH-DPAT (0.1 mg/kg, s.c.) and buspirone (5 mg/kg, i.p.), respectively. In all the treatments, antinociceptive response was inhibited in the presence of WAY 100635 (0.12 mg/kg, i.p.). Our results support the analgesic activity of T. americana var. mexicana inflorescences attributed by folk medicine; they also indicate that quercetin is partly responsible for this pharmacological activity that is likely mediated by serotonin 5-HT(1A) receptors.
authors.affiliation: Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz, Dirección de Investigaciones en Neurociencias, Calz. México-Xochimilco No. 101, Col. San Lorenzo Huipulco, 14370 México, D.F., México.
authors.forename: Ana Laura
authors.initials: AL
authors.lastname: Martínez
authors.forename: Ma Eva
authors.initials: ME
authors.lastname: González-Trujano
authors.forename: Eva
authors.initials: E
authors.lastname: Aguirre-Hernández
authors.forename: Julia
authors.initials: J
authors.lastname: Moreno
authors.forename: Marco
authors.initials: M
authors.lastname: Soto-Hernández
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: López-Muñoz
mesh_terms: D000818:Animals; D019540:Area Under Curve; D001168:Arthritis / Q000175:diagnosis / Q000209:etiology; D001522:Behavior, Animal / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D008297:Male; D010146:Pain / Q000188:drug therapy* / Q000209:etiology; D010147:Pain Measurement / Q000379:methods*; D008517:Phytotherapy / Q000379:methods*; D010879:Piperazines / Q000494:pharmacology; D010936:Plant Extracts / Q000627:therapeutic use*; D011725:Pyridines / Q000494:pharmacology; D011794:Quercetin / Q000627:therapeutic use*; D051381:Rats; D017208:Rats, Wistar; D012702:Serotonin Antagonists / Q000494:pharmacology; D032384:Tilia
chemical_list: D010879:Piperazines; D010936:Plant Extracts; D011725:Pyridines; D012702:Serotonin Antagonists; C090413:N-(2-(4-(2-methoxyphenyl)-1-piperazinyl)ethyl)-N-(2-pyridinyl)cyclohexanecarboxamide; D011794:Quercetin