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Addis Ababa University Libraries Electronic Thesis and Dissertations: AAU-ETD! >
Faculty of Medicine >
Thesis - Medical Physiology >
Please use this identifier to cite or link to this item:
http://hdl.handle.net/123456789/909
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| Title: | HYPOTENSIVE EFFECTS OF AQUEOUS EXTRACT OF Moringa stenopetala IN BOTH in vivo AND in vitro ANIMAL MODELS |
| Authors: | Mekoya, Mengistu |
| Advisors: | Professor Yekoye Abebe |
| Keywords: | Hypertention; Moringa stenopetala; Aqueous extract; in vitro; in vivo; Blood pressure; Acute toxicity; Phytochemical Screening |
| Copyright: | 2007 |
| Date Added: | 23-Apr-2008 |
| Publisher: | Addis Ababa University |
| Abstract: | Abstract
Hypertension is sustained elevation of arterial blood pressure. It is the major cardiovascular
risk factor contributing to myocardial infarction, cerbrovascular accidents, congestive heart
failure, peripheral vascular insufficiency and premature mortality. Different medicinal plants
have been used to treat hypertension. One such plant is Moringa stenopetala, a tree whose
leaves, flowers, and fruits are used as vegetable in some areas of Southern Ethiopia. Different
parts of M. stenopetala are also used to cure various diseases including hypertension. In this
study, the in vivo and in vitro hypotensive properties of aqueous leaf extracts of Moringa
stenopetala have been assessed on selected animal model. The crude aqueous leaf extract of
M. stenopetala caused significant fall in systolic blood pressure (SBP), diastolic blood
pressure (DBP) and mean arterial blood pressure (MABP) at the doses of 10, 20, 30 and 40
mg/kg in normotensive anaesthetized guinea pigs (n = 12). The percent fall in SBP was 25.42
± 4.3% (p = 0.00), 33.3 ± 3.9% (p = 0.00), 41.27 ± 3.7% (p = 0.00), and 51.73 ± 3.9% (p =
0.00) at the respective doses of 10, 20, 30 and 40 mg/kg. At the same dose the percent fall in
DBP was 27.76 ± 3.1% (p = 0.00), 38.38 ± 3.7% (p = 0.00), 52.51 ± 4.1% (p = 0.00) and
59.91 ± 3.7% (p = 0.00). The percent fall in MABP was also 26.74 ± 3.6% (p = 0.00), 36.2 ±
3.5% (p = 0.00), 47.62 ± 3.6% (p = 0.00) and 56.39 ± 3.5 % (p = 0.00) at the above respective
doses. However, significant percent fall in pulse pressure was observed only at the cumulative
dose of 40 mg/kg and the fall was 33.86 ± 8.9% (p = 0.01). The hypotensive effect might have
been mediated by non-autonomic nervous system as its effect is not altered by atropine, which
is muscarinic receptor blocker of acetylcholine, and propranolol, which is non-selective
blocker of b-adrnergic receptors. The in vitro hypothensive study of M. stenopetala was
carried out on isolated guinea pig aorta. High-K+ (80mM) induced sustained contraction of
the aortic tissue preparation. However, the aqueous leaf extract of M. stenopetala caused dose
and time dependent inhibition (vasodilation) of the induced contraction. The significant
inhibition of high K+-induced contraction was 36.55 ± 8.64% (p = 0.001), 67.76 ± 9.55% (p =
0.00), and 95.56 ± 3.14% (p = 0.00) at respective doses of 5, 6 and 7 mg/ml (n = 10 and data
are expressed as M ± SEM). Thus, the in vivo and in vitro studies justify traditional use of the
leaves of M. stenopetala as antihypertensive agent by some localities of Southern Nations
Nationalities and Peoples, Ethiopia. Furthermore, acute toxicity study of M. stenopetala
showed that the extract was tolerable in mice when tested up to the oral dose of 10 g/kg with no mortality and behavioral changes. This also signifies that the leaves of the plant can be a
safe source of food. |
| Description: | A Thesis Submitted to the School of Graduate Studies of Addis Ababa University
in Partial Fulfillment of the Requirements for the Degree of Master of Science in
Medical Physiology |
| URI: | http://hdl.handle.net/123456789/909 |
| Appears in: | Thesis - Medical Physiology
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