Mechanism of action of the aqueous seed extract ofMucuna pruriens on the guinea-pig ileum

Following anaphylactic contraction of actively sensitized, isolated guinea pig ileum segments in a continuously aerated system, spontaneous relaxation ensues. Interruption of aeration during anaphylactic contraction consistently inhibited the relaxation phase. If aeration was resumed, relaxation promptly ensued. Such relaxation was not an all-or-none reaction, but could be made to occur in stepwise fashion by intermittent interruption of aeration. These effects of interruption of aeration on muscle tone during anaphylaxis appeared specific, since opposite tone changes were observed during contractions induced with exogenous histamine. Studies with Tyrode's solution, pretreated with 100% O2 or with 98.5% O2–1.5% CO2, suggested that the mechanism of action of aeration was, in part at least, mediated by an oxygen-dependent process and implicated the active participation of intracellular histamine-inactivating systems. Although postanaphylactic ileum relaxation was also accelerated in Tyrode's solution pretreated with 100% N2, this effect differed in important details from accelerated relaxation in oxygenated systems and appeared to depend upon impaired ability of the contractile system to respond to released histamine.

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Mechanism of action of substance P in guinea-pig ileum longitudinal smooth muscle: a re-evaluation.

The Journal of Physiology ◽

10.1113/jphysiol.1990.sp018345 ◽

1990 ◽

Vol 431 (1) ◽

pp. 529-541 ◽

Cited By ~ 3

Author(s):

J M Hall ◽

I K Morton

Keyword(s):

Smooth Muscle ◽

Substance P ◽

Guinea Pig ◽

Mechanism Of Action ◽

Guinea Pig Ileum ◽

Longitudinal Smooth Muscle

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Study of Antispasmodic and Antidiarrheal Activities of Tagetes lucida (Mexican Tarragon) in Experimental Models and Its Mechanism of Action

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2020/7140642 ◽

2020 ◽

Vol 2020 ◽

pp. 1-10

Author(s):

Rosa Ventura-Martinez ◽

Guadalupe Esther Angeles-Lopez ◽

Maria Eva Gonzalez-Trujano ◽

Omar F. Carrasco ◽

Myrna Deciga-Campos

Keyword(s):

Guinea Pig ◽

Mechanism Of Action ◽

Gastrointestinal Transit ◽

Experimental Models ◽

Gastrointestinal Disorders ◽

Guinea Pig Ileum ◽

Antispasmodic Activity ◽

Response Curves ◽

Antispasmodic Effect ◽

Antidiarrheal Activity

Tagetes lucida has been used in traditional medicine as a remedy to alleviate several gastrointestinal disorders that provoke stomachaches, abdominal cramps, and diarrhea. However, there is not enough scientific evidence that supports these effects. Therefore, the purpose of this study was to evaluate antispasmodic and antidiarrheal activities of aqueous extract of T. lucida (AqExt-TL) as well as its mechanism of action in experimental models. Antispasmodic activity and the mechanism of action of AqExt-TL were assessed on segments of the guinea pig ileum precontracted with KCl, acetylcholine (ACh), or electrical field stimulation (EFS). Furthermore, the antispasmodic effect of two coumarins (umbelliferone and herniarin) previously identified in this species was evaluated. Antidiarrheal activity of AqExt-TL was determined using the charcoal meal test in mice. AqExt-TL showed antispasmodic activity in segments of the guinea pig ileum precontracted with KCl (83.7 ± 1.9%) and ACh (77.2 ± 5.3%) at the maximal concentration; however, practically, it did not alter the contractions induced by EFS (10.1 ± 2.2%). Antispasmodic activity of AqExt-TL was not significantly altered by hexamethonium (a ganglionic blocker) or L-NAME (an inhibitor of nitric oxide synthase). However, this extract decreased the maximal contractile response to calcium (82.7 ± 8.5%), serotonin (68.1 ± 8.5%), and histamine (63.9 ± 5.9%) in their concentration-response curves. Umbelliferone and herniarin also induced an antispasmodic effect on tissues precontracted with KCl. In addition, low doses of AqExt-TL reduced to 50% the distance traveled by charcoal meal in the gastrointestinal transit model in mice as loperamide, an antidiarrheal agent, did. These results provided evidence of the antispasmodic and antidiarrheal activity of T. lucida, which supports its use in the folk medicine in relieving symptoms in some gastrointestinal disorders. In the antispasmodic effect, the blockade of histaminergic and serotoninergic pathway as well as the calcium channels seems to be involved. Finally, umbelliferone and herniarin could be partially responsible for the antispasmodic activity induced by T. lucida.

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