title: A novel herbal preparation desensitizes mesenteric afferents to bradykinin in the rat small intestine.
abstract: Herbal preparations are evolving as promising agents for the treatment of functional gastrointestinal disorders which are considered to be secondary to visceral hypersensitivity. We aimed to determine whether a new combination of six herbal extracts reduces the sensitivity of intestinal afferents in rat. Male Wistar rats (250-350 g, n = 6 per group) were gavaged with either vehicle or 2.5, 5 or 10 mL kg(-1) of STW 5-II, a herbal preparation which contains six extracts. Two hours later, animals were anaesthetized and extracellular multi-unit mesenteric afferent nerve recordings were obtained in the proximal jejunum in vivo. Afferent discharge to 5-hydroxy-tryptamine (5-HT) (5, 10, 20 and 40 microg kg(-1), i.v.), luminal distension (0-60 mmHg) and bradykinin (BK) (15, 30 and 60 microg kg(-1), i.v.) was recorded. At baseline, spontaneous afferent discharge was not different following pretreatment with the various doses of STW 5-II compared with vehicle. The pressure-dependent increase in afferent discharge to intraluminal ramp distension and the dose-dependent increase in afferent firing following 5-HT were also uninfluenced by STW 5-II pretreatment. In contrast, the afferent nerve responses to 15, 30 and 60 microg kg(-1) of BK were reduced following 10 mL kg(-1) STW 5-II with peaks at 106 +/- 19, 153 +/- 22 and 156 +/- 25 imp s(-1) compared with 160 +/- 15, 228 +/- 14 and 220 +/- 16 imp s(-1) following vehicle pretreatment (mean +/- SEM, P < 0.05). Intestinal afferent sensitivity to BK which plays a prime role in nociception was reduced following STW 5-II. Thus, STW 5-II may be of therapeutic use for conditions that involve neuronal hypersensitivity and the release of BK in the intestine.
authors.affiliation: Institute of Surgical Research, Ludwig-Maximilan's University, Munich, Germany.
authors.forename: M H
authors.initials: MH
authors.lastname: Mueller
authors.forename: Q
authors.initials: Q
authors.lastname: Gong
authors.forename: O
authors.initials: O
authors.lastname: Kelber
authors.forename: M S
authors.initials: MS
authors.lastname: Kasparek
authors.forename: A
authors.initials: A
authors.lastname: Sibaev
authors.forename: U
authors.initials: U
authors.lastname: Mansmann
authors.forename: B
authors.initials: B
authors.lastname: Yuce
authors.forename: Y Y
authors.initials: YY
authors.lastname: Li
authors.forename: M
authors.initials: M
authors.lastname: Storr
authors.forename: M E
authors.initials: ME
authors.lastname: Kreis
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D001920:Bradykinin / Q000378:metabolism*; D004594:Electrophysiology; D007421:Intestine, Small / Q000187:drug effects* / Q000294:innervation; D008297:Male; D008643:Mesentery / Q000294:innervation; D017288:Pain Threshold / Q000187:drug effects; D028321:Plant Preparations / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D017833:Visceral Afferents / Q000187:drug effects*
chemical_list: D028321:Plant Preparations; D001920:Bradykinin