Antihypertrophic effects of the seed ethanolic extract of Aframomum
pruinosum Gagnep. (Zingiberaceae) against isoproterenol-induced cardiac
hypertrophy in male Wistar rat
Abstract
The seeds of ethanolic extract Aframomum pruinosum (EE) are
popularly used in the management of cardiovascular conditions. This
study was undertaken to evaluate the capacity of EE to prevent the
development of cardiac hypertrophy in rats. Isoproterenol (0.3
mg/kg/day, sc) was injected to male rats alone or concomitantly
with EE (37.5, 75, or 150 mg/kg, per os) or propranolol (20
mg/kg/day, per os) for 7 consecutive days and Systolic blood
pressure (SBP), diastolic blood pressure (DBP), and heart rate
measurements were performed. Cardiac homogenates were used to assay
myeloperoxidase (MPO), superoxide dismutase (SOD), catalase, nitric
oxide (NO) and reduced glutathione (GSH). Also, sections of heart tissue
were stained with Hematoxylin-Eosin, Masson trichrome, or for
immunohistological labelling of atrial natriuretic peptide (ANP).
Chemical profiling of EE was done by gas chromatography-mass
spectrometry (GC-MS). Isoproterenol administration caused a decline in
SBP and DBP (p < 0.001). Heart rate, cardiac mass,
cardiomyocyte surface, and MPO levels were significantly (p <
0.001) increased. All these alterations were significantly prevented (p
< 0.01 and p < 0.001) by EE. EE inhibited immune
cell infiltration and cardiac fibrosis elicited by isoproterenol
injection. The overexpression of ANP in the atrium and ventricle induced
by the isoproterenol was significantly (p < 0.001) prevented
by EE. GC-MS analysis showed that EE possesses many compounds mainly
nerolidol 2. EE possesses antihypertrophic effect against
isoproterenol-induced cardiac hypertrophy that may result from its
antifibrotic, anti-inflammatory properties, as well as its capacity to
down regulate the expression of ANP.