TITLE:
Effects of methanolic extract of yohimbe bark (Pausinystalia yohimbe) on isolated rabbit aortic strip and rat uterus
AUTHORS:
Hozeifa Mohamed Hassan, Imad Mohamed Taj Eldin, Elhadi Mohamed Ahmed, Abd Elwahab Hassan Mohamed, Nizar Sirag
KEYWORDS:
P. yohimbe Bark; Isolated Tissues; Aortic Strip; Rat Uterus; Relaxation; Nitric Oxide
JOURNAL NAME:
Health,
Vol.5 No.6,
June
11,
2013
ABSTRACT: Background: Medicinal plants
contain physiologically active principles that over the years have been
exploited in traditional medicine for the treatment of various ailments. Objectives and Methods: This study
aimed to investigate the effects of the methanolic extract of Pausinystalia
yohimbe bark (5 mg/ml) on isolated rabbit aortic strip and rat uterus. Results: methanolic extract of P.
yohimbe bark (5 mg/ml) produced relaxation of the phenylephrine precontracted-rabbit
aortic strip. This relaxation may be resulted through nitric oxide (NO), since
the pretreatment of the isolated rabbit aortic strip with methylene blue
inhibited the NO-mediated relaxation. Moreover, the extract exhibited
relaxation of rat uterine muscles, which appeared to be not mediated by activation
of β2-adrenoceptors and/or
H2 receptors, since the relaxant
effect continued even after the pretreatment of the tissue with
propranolol and ranitidine respectively. Conclusion: The obtained results
revealed that methanolic extract of P. yohimbe bark caused relaxation
of both isolated rat uterus and rabbit
aortic strip through facilitating the role of endogenous compounds such as NO.