In-vitro cardiovascular effects of gynura procumbens (lour.) and orthosiphon stamineus (benth.)
Loading...
Date
2004
Authors
Saad Saleh, Omar
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Gynura procumbens and Orthosiphon stamineus have been used as traditional medicine to treat hypertension. This study has shown that both Gynura procumbens and orthosiphon stamineus inhibit cardiac activity and cause vasodilatation, the two mechanisms which contributed to the lowering of blood pressure. The cardiac activity was evaluated using aortic strip preparations isolated from
Sprague Dawley (SD) rats. The dried pulverized G. procumbens leaves were serially extracted with petroleum ether and followed by methanol. The methanol extract was found to inhibit the isoprenaline-induced inotropic activity of right atria more than the petroleum ether extract. The methanol extract was then fractionated into chloroform, ethyl acetate, n-butanol and water fractions. Fraction n-butanol was found to cause the
strongest inhibition for both cardiac right and left atria activities. Fraction n-butanol was then fractionated again using day flash column chromatography to afford three sub-fractions : (Bf1 - Bf3) The results showed that, sub-fraction Bh caused the strongest
inhibition of the inotropic effect induced by isoprenaline in both right and left atria
which suggest the compound (s) with cardiac activity is in sub-fraction B/3.
Among the fraction obtained from methanol extract above the chloroform fraction was
;·. found to cause the strongest inhibition on noradrenaline induced contraction o fa ortic strip. The chloroform extract was then fractionated again using dry column
chromatography to afford five sub-fractions (C/1- Cf5). Our results show that, sub~'
,~,5
\· fraction C f 3 caused the strongest inhibition of the contraction induced by noradrenaline. The second plant studied, was 0. stamineus. Dried powdered leaves of 0. stamineus were serially extracted with petroleum ether, chloroform, methanol and lastly macerated in water
The chloroform extract was found to cause the strongest inhibition of noradrenaline- ·- induced contraction in aortic strip preparartion. The chloroform extract was
then fractionated using dry flash column chromatography to afford five fractions
(Cf- Cf5). Fraction Ch was found to cause the strongest inhibition of contraction induced by noradrenaline. Preliminary phytochemical analysis by thin layer chromatography using specific spray regents showed
showed that sub-fraction Bh and C/3 of G. procumbens and fraction Ch of 0. stamineus contained flavonoids, terpenoids and coumarins. Based on previous studies by Duarite et al. (2001) flavonoids have been known to cause. Therefore it is seems 1 ikely that the vasodilatation caused by G. p rocumbens and 0 .
. stamineus extracts were attributed to flavonoids (TLC studies). The inhibition of the
· cardiac and vascular activity of the plants may explain their use for treatment of high
blood pressure in traditional medicine.
Description
Keywords
Cardiovascular effects , Orthosiphon stamineus (bent.)