Smooth muscle relaxation activity of an aqueous extract of dried immature fruit of Poncirus trifoliata (PF-W) on an isolated strip of rat ileum.
We demonstrated that an aqueous extract of dried immature fruit of Poncirus trifoliate (PF-W) produces relaxation of intestinal smooth muscle using the ileac strips of a rat. Furthermore, the underlying mechanism of its relaxant activity was investigated. PF-W was prepared using the standard extraction protocol. A 1.5 - 2 cm long rat ileac strip was placed in an organ bath with Tyrode's solution and smooth muscle contractility was recorded by connecting it to a force transducer. Various compounds were added to the organ baths, and changes in muscular contractility were measured. PF-W concentration-dependently induced relaxation of rat ileac strips that were contracted both spontaneously and via acetylcholine treatment. Various potassium channel blockers did not inhibit the relaxation by PF-W. No difference in the effect of PF-W was observed between ileac strips treated with low (20 mM) and high concentrations (60 mM) of KCl. PF-W inhibited the contraction of rat ileac strips induced by extracellular calcium. PF-W acts as a potent smooth muscle relaxant, implicating its possible action as a rapid acting reliever for abdominal pains and a cure for intestinal convulsion. Considering that PF-W also exhibits prokinetic activity, its use in various gastrointestinal disorders seems promising.
College of Pharmacy, Seoul National University, Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea.
Kyu-Sang
KS
Kim
Won-Sik
WS
Shim
Ike Campomayor
IC
dela Peña
Eun-Kyung
EK
Seo
Woo-Young
WY
Kim
Hyo-Eon
HE
Jin
Dae-Duk
DD
Kim
Suk-Jae
SJ
Chung
Jae-Hoon
JH
Cheong
Chang-Koo
CK
Shim
D000818:Animals; D005638:Fruit / Q000737:chemistry; D005765:Gastrointestinal Agents / Q000032:analysis / Q000494:pharmacology*; D005769:Gastrointestinal Motility / Q000187:drug effects; D007082:Ileum / Q000187:drug effects*; D066298:In Vitro Techniques; D008297:Male; D009130:Muscle, Smooth / Q000187:drug effects*; D010936:Plant Extracts / Q000494:pharmacology*; D032104:Poncirus / Q000737:chemistry*; D051381:Rats; D017207:Rats, Sprague-Dawley
D005765:Gastrointestinal Agents; D010936:Plant Extracts