title: Dietary agonists of TRPV1 inhibit gastric acid secretion in mice.
abstract: Capsaicin and 6-gingerol, pungent components of chilli pepper and ginger, are known as dietary agonists of transient receptor potential vanilloid-1. Transient receptor potential vanilloid-1 nerve fibers are recognized to play a role in gastric mucosal integrity in rats. In the present studies, we examined the acute effects of peroral administration of capsaicin and 6-gingerol on gastric acid secretion in conscious mice. These agents were given p. o. 30 min before the pylorus was ligated. Oral administration of capsaicin (1.0-100 mg/kg) or 6-gingerol (1.5-50 mg/kg) significantly and dose-dependently inhibited basal acid secretion. Pretreatment with BCTC, a transient receptor potential vanilloid-1 antagonist, significantly reversed the reduced basal acid secretion by capsaicin or 6-gingerol. The combination of the lowest doses of capsaicin and 6-gingerol markedly inhibited basal acid secretion in conscious mice and this was also significantly reversed by BCTC. Moreover, the combination of the maximal dose of capsaicin and 6-gingerol inhibited basal acid secretion only to the level of a single administration of the maximal dose of capsaicin. These results suggest that the combination of capsaicin and 6-gingerol has an additive effect on the inhibition of gastric acid secretion through activation of transient receptor potential vanilloid-1. In separate experiments, intraduodenal administration of either capsaicin (30 mg/kg) or 6-gingerol (15 mg/kg), whose doses were observed to have a significant inhibitory effect by oral administration, tended to inhibit basal acid secretion compared with the vehicle. These results suggest that the combination of capsaicin and 6-gingerol has an additive effect on inhibition of gastric acid secretion through activation of transient receptor potential vanilloid-1, and oral administration of transient receptor potential vanilloid-1 agonists directly stimulates transient receptor potential vanilloid-1 in the gastric lumen, resulting in a potent reduction of gastric acid secretion.
authors.affiliation: Laboratory of Pharmacology, Faculty of Pharmaceutical Sciences, Josai International University, Togane, Chiba, Japan.
authors.forename: Hirokuni
authors.initials: H
authors.lastname: Okumi
authors.forename: Kimihito
authors.initials: K
authors.lastname: Tashima
authors.forename: Kenjiro
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Takao
authors.initials: T
authors.lastname: Namiki
authors.forename: Katsutoshi
authors.initials: K
authors.lastname: Terasawa
authors.forename: Syunji
authors.initials: S
authors.lastname: Horie
mesh_terms: D000284:Administration, Oral; D000818:Animals; D002211:Capsaicin / Q000008:administration & dosage / Q000494:pharmacology*; D002212:Capsicum / Q000737:chemistry; D002396:Catechols / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D004359:Drug Therapy, Combination; D005233:Fatty Alcohols / Q000008:administration & dosage / Q000494:pharmacology*; D005744:Gastric Acid / Q000378:metabolism*; D005753:Gastric Mucosa / Q000187:drug effects; D020939:Zingiber officinale / Q000737:chemistry; D008297:Male; D051379:Mice; D010936:Plant Extracts / Q000494:pharmacology; D050916:TRPV Cation Channels / Q000819:agonists*
chemical_list: D002396:Catechols; D005233:Fatty Alcohols; D010936:Plant Extracts; D050916:TRPV Cation Channels; C007845:gingerol; D002211:Capsaicin