ABSTRACT
Aristolochia ringens Vahl. (Aristolochiaceae (AR); mÇ dou líng) is used traditionally in Nigeria for the management of various disorders including oedema. Preliminary investigation revealed its modulatory effect on the cardiovascular system. This study was aimed at investigating the effect of the aqueous root extract of A. ringens (AR) on haemodynamic parameters of spontaneously hypertensive rats (SHRs). The effect of oral subacute (21 days) and intravenous acute exposure of SHRs to the extract were assessed using tail cuff and carotid artery canulation methods respectively. In the latter, the effect of chloroform, butanol and aqueous fractions of AR were also evaluated. The extract significantly reduced systolic and diastolic blood pressures in SHRs, with peak reductions of 20.3% and 26.7% respectively at 50 mg/kg by the 21st day of oral subacute exposure. Upon intravenous exposure, AR (50 mg/kg) reduced systolic and diastolic blood pressure by as much as 53.4 ± 2.2 and 49.2 ± 2.8 mmHg respectively. A dose-dependent reduction in heart rate, significant at 25 and 50 mg/kg was also observed. Hexamethonium (20 mg/kg) and atropine (1 mg/kg) inhibited the extract's reduction of systolic blood pressure, diastolic blood pressure and heart rate significantly. The extract's butanol fraction produced the greatest systolic and diastolic blood pressures reduction of 67.0 ± 3.8 and 68.4 mmHg respectively at 25 mg/kg and heart rate reduction of 40 ± 7 beats per minute at 50 mg/kg. HPLC analysis revealed the presence of 4-hydroxybenzoic acid and quercetin in AR. The extract's alterations of haemodynamic parameters in this study show that it has hypotensive effect on spontaneously hypertensive rats.
ABSTRACT
Telfairia occidentalis possesses high antioxidant activity. However, the antioxidant components of the plant have not yet been identified. This study was undertaken to identify the phenolics in the leaf of the plant. Extract and fractions of the leaf of the plant were analysed using the HPLC and GCMS. HPLC analysis revealed the presence of gallic acid (22.19µg/mg), catechin (29.17µg/mg), caffeic acid (9.17µg/mg), ferulic acid (0.94µg/mg), sinapic acid (1.91 µg/mg) and 4-hydroxy benzoic acid (43.86 µg/mg) in the aqueous extract. Phenolics fraction contained gallic acid (0.88 µg/mg), catechin (2.70µg/mg), caffeic acid (7.92µg/mg), ferulic acid (2.72µg/mg), benzoic acid (6.36µg/mg), p-coumaric acid (1.48µg/mg), quercetin (12.00µg/mg). Only caffeic acid (2.50µg/mg), ferulic acid (0.44µg/mg) and quercetin (8.50µg/mg) were detected in the flavonoid fraction. While GCMS analysis showed the presence of methylparaben; ethylparaben; benzoic acid; 4-hydroxy-2-methoxy-3,5,6-trimethyl-, methyl ester; 4-hydroxy-3-methoxy; phenol, 5-methoxy-2-(methoxymethyl)-; phenol, 5-methoxy-2, 3- dimethyl; and phenol, 2-(2-benzothiazolyl)-. This study is the first to reveal the identity of some phenolics components of the leaf of Telfairia occidentalis.
Subject(s)
Antioxidants/isolation & purification , Cucurbitaceae/chemistry , Flavonoids/isolation & purification , Phenols/isolation & purification , Plant Leaves/chemistry , Chromatography, High Pressure Liquid , Gas Chromatography-Mass SpectrometryABSTRACT
Left ventricular hypertrophy (LVH) is a compensatory mechanism in response to an increased work load on the heart. This study investigated the impact of chronic isoprenaline and caffeine (I/C model) administration on cardiac geometry, systemic hemodynamic and physiological data in rats as LVH develops. LVH was induced by administering isoprenaline (5 mg/kg s.c. every 72 h) and caffeine (62 mg/L) in drinking water for 14 days to Wistar Kyoto (WKY) rats. Mean arterial pressure (MAP), systolic blood pressure (SBP), heart weight, LV weight, LV chamber diameter and thickness of myocardium were observed as LVH indicators. MAP was significantly higher (142 ± 13 vs. 119 ± 2 mmHg, respectively) while heart rate (HR) in LVH was lower (314 ± 9 vs. 264 ± 18 BPM) compared to control WKY. Heart weight, LV weight and kidney weight were 31%, 38% and 7%, respectively, greater in the LVH group as compared to the control WKY (all p < 0.05).The myocardium thickness was 101% greater while LV chamber diameter was 44% smaller in the LVH group as compared to the control WKY (p < 0.05). The superoxide dismutase (SOD), glutathione reductase (GSH) and total antioxidant capacity (T-AOC) levels were significantly reduced while malonodialdehyde (MDA) level increased in LVH as compared to control WKY (all p < 0.05). In conclusion, isoprenaline and caffeine (I/C) induces LVH and cardiac hypertrophy with increases in blood pressure, fluid excretion and reduced renal hemodynamics. Prooxidant mechanism of the body and arterial stiffness are dominant in this disease model. This model of LVH is easily generated and associated with low mortality.
