Acetylene compound isolated from Atractylodes japonica stimulates the contractility of rat distal colon via inhibiting the nitrergic-purinergic relaxation.
OBJECTIVE
Our previous research has showed that rhizome of Atractylodes japonica Koidz (Compositae) exhibits an increase in the spontaneous contractility of distal colon in rats. The aims of this study are to identify the phytochemical(s), which stimulate(s) the colonic contractility, contained in Atractylodes japonica and to evaluate the pharmacological mechanism responsible for the colonic muscle contraction.


METHODS
Based on the stimulatory activity-guided fractionation on the isometric contraction of rat distal colonic strips, atractylodiol (ATD) and diacetyl-atractylodiol (DATD) were isolated from the CHCl(3) fractions of Atractylodes japonica.


RESULTS
ATD and DATD dose-dependently increased both tension and amplitude of distal colon longitudinal muscle (DCLM), but they stimulated only amplitude in the distal colon circular muscle. The ED(50) values of ATD and DATD to stimulate the amplitude of DCLM were revealed as 9.1×10(-9)M and 1.8×10(-8)M, respectively. l-NAME (0.1mM) significantly increased the ADT (1μM)-induced contraction of DCLM, whereas SNAP (0.1mM) markedly reduced the stimulatory effects of ATD on DCLM contractility. The combined effects of SNAP and atropine (0.5μM) on the ATD-induced contraction of DCLM were similar to the inhibitory effects of SNAP alone. Suramin (0.1mM) significantly enhanced the increase of ATD-induced DCLM contraction, whereas ADPβS (0.1mM) markedly abolished the stimulatory effects of ATD on the spontaneous contractility of DCLM.


CONCLUSIONS
The present results demonstrate that acetylene compounds, ATD and DATD, are the effective phytochemical of Atractylodes japonica to stimulate the motility of distal colon in rats, and ATD possibly enhances the spontaneous contractility of distal colon through inhibiting the mechanism of nitrergic-purinergic relaxation.
Department of Pharmacology, College of Medicine, Wonkwang University, 344-2 Shinyong-dong, Iksan, Jeonbuk 570-749, Republic of Korea.
Keun Han
KH
Choi
Seung Il
SI
Jeong
Jun Ho
JH
Lee
Byung Soon
BS
Hwang
Seoul
S
Lee
Bong Kyu
BK
Choi
Kyu Yong
KY
Jung
D000114:Acetylene / Q000302:isolation & purification / Q000494:pharmacology*; D000818:Animals; D031174:Atractylodes / Q000737:chemistry*; D003106:Colon / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D026602:Nitrergic Neurons / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011983:Receptors, Purinergic / Q000378:metabolism*
D011983:Receptors, Purinergic; D000114:Acetylene