Abstract
Ethnopharmacological
relevance:
The leaves of Artocarpus altilis (Parkinson ex F.A.Zorn, Fosberg)
(Moraceae) are used in the management of hypertension; this study
assessed the cardio-protective effects of the leaf extract on
isoproterenol (ISO) induced myocardial damage in rats.
Material and methods:
Twenty (20) adult male Sprague-Dawley rats (175-230g) were divided into 5
groups. Group 1 (Control), 2 (AA) received 50mg/Kg Artocarpus altilis
(AA) only; 3 (ISO) received 85mg/Kg ISO only; 4 (ISO+AA/50) and 5
(ISO+AA/100) received 50 and 100mg/Kg AA respectively for 6 days, after
induced with ISO twice (85mg/Kg) at a 24-hour period. Blood pressure
readings were taken before and after the administering of ISO using the
tail cuff method. ECG was performed on anaesthetized rats. Cardiac
contractility was measured in isolated right atrial muscles. Assessment
of myocardial infarct (MI) size, heart/body weight ratio, biochemical,
hematological and histo-morphological parameters were conducted at the
end of seven days. An aqueous extract from leaves of A. altilis was
analyzed for organic compounds using UHPLC mass spectrometry.
Results:
ISO induced myocardial damage through an elevation of the heart rate
(HR), infarct size and ECG distortions. Treatment with AA significantly
(p?0.05) reduced heart/body weight ratio (49%), MI (96%), HR (27%),
sympathovagal imbalance (36%) and serum cardiac biomarkers (AST, LDH,
HDL, triglycerides and CCK) caused by ISO. AA decreased the beat
frequency of isolated right atrium (11%) cause by ISO, an action similar
to propranolol (beta-adrenergic antagonist; 20%), but showed no
significant changes in the QTc intervals of the ECG (suggesting no
cardio-toxic drug-herb interactions), Thirty nine compounds were
detected using high resolution LC-MS analysis (HPLC-Orbitrap-APCI-MS) in
the extract. Pure compounds, as gallic acid and rutin, presented a
higher negative chronotropic effect, similar to propranolol.
Conclusion:
Oral administration of aqueous extract of Artocarpus artilis has
cardio-protective functions in myocardial injury, in part, by decreasing
the HR, reduced contractility and infarct size. These findings may
explain the cardio-protective use of A. altilis in traditional medicine.
