Relaxant and contractile effect of dry extracts from Thevetia peruviana (Tp) seed upon different smooth muscles of rat
Por:
Enríquez M.E.M., Guerrero G.A.M., Contreras A.A., Sepúlveda A.E.C.
Publicada:
1 ene 2006
Resumen:
The Thevetia peruviana seed (Tp) produces gastrointestinal and uterine toxicity in humans and urinary retention in experimental animals. The purpose of this study was to identify the effects of ethyl acetate (EA), methanol (MET) and aqueous (AQ) extracts upon smooth muscle of bladder, uterus and intestine obtained from Wistar rats. Uterine and intestinal tissues were cut in segments of 1-2 cm and the bladder was cut transversally obtain the detrusor and trigon muscles. In experiments with intestine and bladder, the baths contained Krebs solution to 37°C and the uterus contained De Jalon solution to 32°C. The solutions were gassed with 95% O 2 + 5% CO 2 and the pH (7.4) was maintained constant throughout the experiments. Muscular contractile responses were recorded isometrically with a transducer connected to a polygraph. Dose-response curves were obtained to acetylcholine alone (1× 10 -6 a 1×10 -3 M) and in the presence the dry extract: EA (1000 ?g/ml), MET y AQ (666.66 ?g/ml). The results indicate that the MET and AQ extracts relax the detrusor but do not modify the trigone. The EA relaxes the detrusor and it diminishes the contraction of the trigone. In the uterine muscle the EA and AQ diminish (p ? 0.05) acetylcholine induced contractions; in contrast the MET increased contractile activity. In the intestine the MET and AQ increased the contractile effect of acetylcholine, while EA had no effect. These results could explain the toxicity shown in vivo at high doses of Tp seed.
Filiaciones:
Enríquez M.E.M.:
Department of Pharmacology, Faculty of Medicine, National University Autonomous of Mexico, P.O. Box 70297, Mexico, D.F. 04510, Mexico
Guerrero G.A.M.:
Department of Pharmacology, Faculty of Medicine, National University Autonomous of Mexico, P.O. Box 70297, Mexico, D.F. 04510, Mexico
Contreras A.A.:
Medicinal Plant Herbarium of the Mexican Institute of Social Security, Mexico
Sepúlveda A.E.C.:
Department of Pharmacology, Faculty of Medicine, National University Autonomous of Mexico, P.O. Box 70297, Mexico, D.F. 04510, Mexico
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