Displaying publications 41 - 60 of 71 in total

Abstract:
Sort:
  1. Fulltext First Report of Eurycoma longifolia Jack Root Extract Causing Relaxation of Aortic Rings in Rats
    Tee BH, Hoe SZ, Cheah SH, Lam SK
    Biomed Res Int, 2016;2016:1361508.
    PMID: 27800486 DOI: 10.1155/2016/1361508
    Although Eurycoma longifolia has been studied for erectile function, the blood pressure- (BP-) lowering effect has yet to be verified. Hence, this study aims at investigating the BP-lowering properties of the plant with a view to develop an antihypertensive agent that could also preserve erectile function. Ethanolic root extract was partitioned by hexane, dichloromethane (DCM), ethyl acetate, butanol, and water. The DCM fraction, found to be potent in relaxing phenylephrine- (PE-) precontracted rat aortic rings, was further purified by column chromatography. Subfraction DCM-II, being the most active in relaxing aortae, was studied for effects on the renin-angiotensin and kallikrein-kinin systems in aortic rings. The effect of DCM-II on angiotensin-converting enzyme (ACE) activity was also evaluated in vitro. Results showed that DCM-II reduced (p < 0.05) the contractions evoked by angiotensin I and angiotensin II (Ang II). In PE-precontracted rings treated with DCM-II, the Ang II-induced contraction was attenuated (p < 0.05) while bradykinin- (BK-) induced relaxation enhanced (p < 0.001). In vitro, DCM-II inhibited (p < 0.001) the activity of ACE. These data demonstrate that the vasodilatory effect of DCM-II appears to be mediated via inhibition of Ang II type 1 receptor and ACE as well as enhancement of Ang II type 2 receptor activation and BK activity.
    Matched MeSH terms: Antihypertensive Agents/pharmacology
  2. Mechanisms underlying the antihypertensive effect of Alstonia scholaris
    Bello I, Usman NS, Mahmud R, Asmawi MZ
    J Ethnopharmacol, 2015 Dec 4;175:422-31.
    PMID: 26429073 DOI: 10.1016/j.jep.2015.09.031
    Alstonia scholaris has a long history of use in the Ayurveda traditional treatment of various ailments including hypertension. We have reported the blood pressure lowering activity of the extract of A. scholaris. The following research aim to delineate the pharmacological mechanism involve in the antihypertensive action.
    Matched MeSH terms: Antihypertensive Agents/pharmacology*
  3. Fulltext Mechanisms of the antihypertensive effects of Nigella sativa oil in L-NAME-induced hypertensive rats
    Jaarin K, Foong WD, Yeoh MH, Kamarul ZY, Qodriyah HM, Azman A, et al.
    Clinics (Sao Paulo), 2015 Nov;70(11):751-7.
    PMID: 26602523 DOI: 10.6061/clinics/2015(11)07
    This study was conducted to determine whether the blood pressure-lowering effect of Nigella sativa might be mediated by its effects on nitric oxide, angiotensin-converting enzyme, heme oxygenase and oxidative stress markers.
    Matched MeSH terms: Antihypertensive Agents/pharmacology*
  4. The role of oxidative stress, antioxidants and vascular inflammation in cardiovascular disease (a review)
    Siti HN, Kamisah Y, Kamsiah J
    Vascul. Pharmacol., 2015 Aug;71:40-56.
    PMID: 25869516 DOI: 10.1016/j.vph.2015.03.005
    The concept of mild chronic vascular inflammation as part of the pathophysiology of cardiovascular disease, most importantly hypertension and atherosclerosis, has been well accepted. Indeed there are links between vascular inflammation, endothelial dysfunction and oxidative stress. However, there are still gaps in our understanding regarding this matter that might be the cause behind disappointing results of antioxidant therapy for cardiovascular risk factors in large-scale long-term randomised controlled trials. Apart from the limitations of our knowledge, limitations in methodology and assessment of the body's endogenous and exogenous oxidant-antioxidant status are a serious handicap. The pleiotropic effects of antioxidant and anti-inflammation that are shown by some well-established antihypertensive agents and statins partly support the idea of using antioxidants in vascular diseases as still relevant. This review aims to provide an overview of the links between oxidative stress, vascular inflammation, endothelial dysfunction and cardiovascular risk factors, importantly focusing on blood pressure regulation and atherosclerosis. In view of the potential benefits of antioxidants, this review will also examine the proposed role of vitamin C, vitamin E and polyphenols in cardiovascular diseases as well as the success or failure of antioxidant therapy for cardiovascular diseases in clinical trials.
    Matched MeSH terms: Antihypertensive Agents/pharmacology
  5. Hydralazine administration activates sympathetic preganglionic neurons whose activity mobilizes glucose and increases cardiovascular function
    Parker LM, Damanhuri HA, Fletcher SP, Goodchild AK
    Brain Res, 2015 Apr 16;1604:25-34.
    PMID: 25662772 DOI: 10.1016/j.brainres.2015.01.049
    Hypotensive drugs have been used to identify central neurons that mediate compensatory baroreceptor reflex responses. Such drugs also increase blood glucose. Our aim was to identify the neurochemical phenotypes of sympathetic preganglionic neurons (SPN) and adrenal chromaffin cells activated following hydralazine (HDZ; 10mg/kg) administration in rats, and utilize this and SPN target organ destination to ascribe their function as cardiovascular or glucose regulating. Blood glucose was measured and adrenal chromaffin cell activation was assessed using c-Fos immunoreactivity (-ir) and phosphorylation of tyrosine hydroxylase, respectively. The activation and neurochemical phenotype of SPN innervating the adrenal glands and celiac ganglia were determined using the retrograde tracer cholera toxin B subunit, in combination with in situ hybridization and immunohistochemistry. Blood glucose was elevated at multiple time points following HDZ administration but little evidence of chromaffin cell activation was seen suggesting non-adrenal mechanisms contribute to the sustained hyperglycemia. 16±0.1% of T4-T11 SPN contained c-Fos and of these: 24.3±1.4% projected to adrenal glands and 29±5.5% projected to celiac ganglia with the rest innervating other targets. 62.8±1.4% of SPN innervating adrenal glands were activated and 29.9±3.3% expressed PPE mRNA whereas 53.2±8.6% of SPN innervating celiac ganglia were activated and 31.2±8.8% expressed PPE mRNA. CART-ir SPN innervating each target were also activated and did not co-express PPE mRNA. Neurochemical coding reveals that HDZ administration activates both PPE+SPN, whose activity increase glucose mobilization causing hyperglycemia, as well as CART+SPN whose activity drive vasomotor responses mediated by baroreceptor unloading to raise vascular tone and heart rate.
    Matched MeSH terms: Antihypertensive Agents/pharmacology
  6. Fulltext The use of Piper sarmentosum leaves aqueous extract (Kadukmy™) as antihypertensive agent in spontaneous hypertensive rats
    Mohd Zainudin M, Zakaria Z, Megat Mohd Nordin NA
    BMC Complement Altern Med, 2015 Mar 10;15:54.
    PMID: 25887182 DOI: 10.1186/s12906-015-0565-z
    BACKGROUND: The National Health and Morbidity Survey in 2011 estimated that 35.1% (5.7 million) of Malaysian adults aged 18 and older suffer from hypertension. Hypertension is still treated by conventional medicine despite its exact aetiology being unknown. Studies showed that oxidative stress and low availability of nitric oxide (NO) causes an increase in vascular wall tension and increase blood pressure. Piper sarmentosum (PS) a traditional Malay herbal plant is well known for its high antioxidant content. Antioxidant is useful in improving cardiovascular diseases particularly hypertension. Thus, it is beneficial to determine the effect of PS leaves aqueous extract (Kadukmy™) on the blood pressure, NO level, oxidative stress markers and serum cholesterol level of the Spontaneous Hypertensive Rats (SHR).

    METHODS: Rats were devided into five groups consisting of three treatment groups and two control groups. Baseline blood investigations were done before and following commencement of treatment. Spontaneous hypertensive rats were treated for 28 consecutive days and the blood pressure was measured weekly.

    RESULTS: Kadukmy™ administration showed a significant reduction in systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP) (P 

    Matched MeSH terms: Antihypertensive Agents/pharmacology
  7. Anterior and posterior segment changes in rat eyes with chronic steroid administration and their responsiveness to antiglaucoma drugs
    Razali N, Agarwal R, Agarwal P, Kapitonova MY, Kannan Kutty M, Smirnov A, et al.
    Eur J Pharmacol, 2015 Feb 15;749:73-80.
    PMID: 25481859 DOI: 10.1016/j.ejphar.2014.11.029
    Steroid-induced ocular hypertension (SIOH) is associated with topical and systemic use of steroids. However, SIOH-associated anterior and posterior segment morphological changes in rats have not been described widely. Here we describe the pattern of intraocular pressure (IOP) changes, quantitative assessment of trabecular meshwork (TM) and retinal morphological changes and changes in retinal redox status in response to chronic dexamethasone treatment in rats. We also evaluated the responsiveness of steroid-pretreated rat eyes to 5 different classes of antiglaucoma drugs that act by different mechanisms. Up to 80% of dexamethasone treated animals achieved significant and sustained IOP elevation. TM thickness was significantly increased and number of TM cells was significantly reduced in SIOH rats compared to the vehicle-treated rats. Quantitative assessment of retinal morphology showed significantly reduced thickness of ganglion cell layer (GCL) and inner retina (IR) in SIOH rats compared to vehicle-treated rats. Estimation of retinal antioxidants including catalase, superoxide dismutase and glutathione showed significantly increased retinal oxidative stress in SIOH animals. Furthermore, steroid-treated eyes showed significant IOP lowering in response to treatment with 5 different drug classes. This indicated the ability of SIOH eyes to respond to drugs acting by different mechanisms. In conclusion, SIOH was associated with significant morphological changes in TM and retina and retinal redox status. Additionally, SIOH eyes also showed IOP lowering in response to drugs that act by different mechanisms of action. Hence, SIOH rats appear to be an inexpensive and noninvasive model for studying the experimental antiglaucoma drugs for IOP lowering and neuroprotective effects.
    Matched MeSH terms: Antihypertensive Agents/pharmacology
  8. Identification of angiotensin-converting enzyme inhibitory proteins from mycelium of Pleurotus pulmonarius (oyster mushroom)
    Ibadallah BX, Abdullah N, Shuib AS
    Planta Med, 2015 Jan;81(2):123-9.
    PMID: 25590365 DOI: 10.1055/s-0034-1383409
    Pleurotus pulmonarius (grey oyster mushroom) has been acknowledged as a recuperative agent for many diseases in addition to its recognition as a nutritious provision. We performed a study on P. pulmonarius mycelium for an antihypertensive effect via the angiotensin-converting enzyme inhibitory activity. The preliminary assay on the mycelial water extract demonstrated that the angiotensin-converting enzyme inhibitory activity had an IC50 value of 720 µg/mL. Further protein purifications via ammonium sulphate precipitation and RP-HPLC resulted in 60× stronger angiotensin-converting enzyme inhibitory activity than that of the mycelial water extract (IC50 = 12 µg/mL). Protein identification and characterisation by MALDI-TOF/TOF, later corroborated by LC-MS/MS, indicated three proteins that are responsible for the blood pressure lowering effects via different mechanisms: serine proteinase inhibitor-like protein, nitrite reductase-like protein, and DEAD/DEAH box RNA helicase-like protein.
    Matched MeSH terms: Antihypertensive Agents/pharmacology*
  9. Fulltext Antioxidant and cytotoxic activities of three species of tropical seaweeds
    Chia YY, Kanthimathi MS, Khoo KS, Rajarajeswaran J, Cheng HM, Yap WS
    BMC Complement Altern Med, 2015;15:339.
    PMID: 26415532 DOI: 10.1186/s12906-015-0867-1
    Three species of seaweeds (Padina tetrastromatica, Caulerpa racemosa and Turbinaria ornata) are widely consumed by Asians as nutraceutical food due to their antioxidant properties. Studies have shown that these seaweeds exhibit bioactivities which include antimicrobial, antiviral, anti-hypertensive and anticoagulant activities. However, investigations into the mechanisms of action pertaining to the cytotoxic activity of the seaweeds are limited. The aim of this study was to determine the antioxidant and cytotoxic activities of whole extracts of P. tetrastromatica, C. racemosa and T. ornata, including the cellular events leading to the apoptotic cell death of the extract treated-MCF-7 cells. Bioassay guided fractionation was carried out and the compounds identified.
    Matched MeSH terms: Antihypertensive Agents/pharmacology
  10. Fulltext Effect of the antihypertensive drug enalapril on oxidative stress markers and antioxidant enzymes in kidney of spontaneously hypertensive rat
    Chandran G, Sirajudeen KN, Yusoff NS, Swamy M, Samarendra MS
    Oxid Med Cell Longev, 2014;2014:608512.
    PMID: 25254079 DOI: 10.1155/2014/608512
    Oxidative stress has been suggested to play a role in hypertension and hypertension induced organ damage. This study examined the effect of enalapril, an antihypertensive drug, on oxidative stress markers and antioxidant enzymes in kidney of spontaneously hypertensive rat (SHR) and Nω -nitro-L-arginine methyl ester (L-NAME) administered SHR. Male rats were divided into four groups (SHR, SHR+enalapril, SHR+L-NAME, and SHR+enalapril+L-NAME). Enalapril (30 mg kg(-1) day(-1)) was administered from week 4 to week 28 and L-NAME (25 mg kg(-1) day(-1)) was administered from week 16 to week 28 in drinking water. Systolic blood pressure (SBP) was measured during the experimental period. At the end of experimental periods, rats were sacrificed; urine, blood, and kidneys were collected for the assessment of creatinine clearance, total protein, total antioxidant status (TAS), thiobarbituric acid reactive substances (TBARS), superoxide dismutase (SOD), and catalase (CAT), as well as histopathological examination. Enalapril treatment significantly enhanced the renal TAS level (P < 0.001) and SOD activity (P < 0.001), reduced the TBARS levels (P < 0.001), and also prevented the renal dysfunction and histopathological changes. The results indicate that, besides its hypotensive and renoprotective effects, enalapril treatment also diminishes oxidative stress in the kidneys of both the SHR and SHR+L-NAME groups.
    Matched MeSH terms: Antihypertensive Agents/pharmacology*
  11. Synthesis and evaluation of chalcone analogues based pyrimidines as angiotensin converting enzyme inhibitors
    Bukhari SN, Butt AM, Amjad MW, Ahmad W, Shah VH, Trivedi AR
    Pak J Biol Sci, 2013 Nov 01;16(21):1368-72.
    PMID: 24511749
    Hypertension is a widespread and frequently progressive ailment that imparts a foremost threat for cardiovascular and renal disorders. Mammoth efforts are needed for the synthesis of innovative antihypertensive agents to combat this lethal disease. Chalcones have shown antihypertensive activity through inhibition of Angiotensin Converting Enzyme (ACE). Hence, a series of chalcone analogues is synthesized and used as precursor for the synthesis of novel series of pyrimidines. Precursor chalcones were prepared by reacting aldehydes and ketones in presence of sodium hydroxide followed by synthesis of corresponding pyrimidines by reaction with urea in presence of potassium hydroxide. Both groups were then evaluated for their effects on ACE. The results depicted that pyrimidines were more active than chalcones with methoxy (C5 and P5) substitution showing best results to inhibit ACE. Given that chalcone analogues and pyrimidines show a potential as the angiotensin converting enzyme inhibitors.
    Matched MeSH terms: Antihypertensive Agents/pharmacology
  12. Fulltext Effect of Clonidine (an antihypertensive drug) treatment on oxidative stress markers in the heart of spontaneously hypertensive rats
    Nik Yusoff NS, Mustapha Z, Govindasamy C, Sirajudeen KN
    Oxid Med Cell Longev, 2013;2013:927214.
    PMID: 23766863 DOI: 10.1155/2013/927214
    Hypertension is a risk factor for several cardiovascular diseases and oxidative stress suggested to be involved in the pathophysiology. Antihypertensive drug Clonidine action in ameliorating oxidative stress was not well studied. Therefore, this study investigate the effect of Clonidine on oxidative stress markers and nitric oxide (NO) in SHR and nitric oxide synthase inhibitor, N-nitro-L-arginine methyl ester (L-NAME) administered SHR. Male rats were divided into four groups [SHR, SHR+Clonidine (SHR-C), SHR+L-NAME, SHR+Clonidine+L-NAME(SHRC+L-NAME)]. Rats (SHRC) were administered with Clonidine (0.5 mg kg(-1) day(-1)) from 4 weeks to 28 weeks in drinking water and L-NAME (25 mg kg(-1) day(-1)) from 16 weeks to 28 weeks to SHRC+L-NAME. Systolic blood pressure (SBP) was measured. At the end of 28 weeks, all rats were sacrificed and in their heart homogenate, oxidative stress parameters and NO was assessed. Clonidine treatment significantly enhanced the total antioxidant status (TAS) (P < 0.001) and reduced the thibarbituric acid reactive substances (TBARS) (P < 0.001) and protein carbonyl content (PCO) (P < 0.05). These data suggest that oxidative stress is involved in the hypertensive organ damage and Clonidine not only lowers the SBP but also ameliorated the oxidative stress in the heart of SHR and SHR+L-NAME.
    Matched MeSH terms: Antihypertensive Agents/pharmacology*
  13. Apocynum venetum leaf extract, an antihypertensive herb, inhibits rat aortic contraction induced by angiotensin II: a nitric oxide and superoxide connection
    Lau YS, Kwan CY, Ku TC, Hsieh WT, Wang HD, Nishibe S, et al.
    J Ethnopharmacol, 2012 Sep 28;143(2):565-71.
    PMID: 22835814 DOI: 10.1016/j.jep.2012.07.012
    The leaves extract of Apocynum venetum (AVLE), also known as "luobuma", have long been used in traditional Chinese medicine to treat hypertension and depression in parts of China and it has been shown to possess anti-oxidant and anti-lipid peroxidation effects. AVLE (10 μg/ml) has been reported to have a long-lasting endothelium-dependent relaxant effect and this effect has been proposed to be due to its nitric oxide(NO)-releasing and superoxide anion(SOA)-scavenging properties.
    Matched MeSH terms: Antihypertensive Agents/pharmacology*
  14. Fulltext Hypotensive effect of Gentiana floribunda is mediated through Ca++ antagonism pathway
    Khan AU, Mustafa MR, Khan AU, Murugan DD
    BMC Complement Altern Med, 2012;12:121.
    PMID: 22883710 DOI: 10.1186/1472-6882-12-121
    Gentiana floribunda was investigated for the possible hypotensive and vasodilator activities in an attempt to rationalize its traditional use in hypertension.
    Matched MeSH terms: Antihypertensive Agents/pharmacology
  15. Angiotensin I-converting enzyme inhibitory activity and bioconversion of isoflavones by probiotics in soymilk supplemented with prebiotics
    Yeo SK, Liong MT
    Int J Food Sci Nutr, 2010 Mar;61(2):161-81.
    PMID: 20085504 DOI: 10.3109/09637480903348122
    Lactobacillus sp. FTDC 2113, L. acidophilus FTDC 8033, L. acidophilus ATCC 4356, L. casei ATCC 393, Bifidobacterium FTDC 8943 and B. longum FTDC 8643 were incorporated into soymilk supplemented with fructooligosaccharides (FOS), inulin, mannitol, maltodextrin and pectin. The objective of the present study was to evaluate the effects of prebiotics on the bioactivity of probiotic-fermented soymilk. Proteolytic activity was increased in the presence of FOS, while the supplementation of inulin and pectin increased the angiotensin I-converting enzyme inhibitory activity accompanied by lower IC(50) values. The beta-glucosidase activity was also enhanced in the presence of pectin. This led to higher bioconversion of glucosides to aglycones by probiotics, especially genistin and malonyl genistin to genistein. Results from this study indicated that the supplementation of prebiotics enhanced the in-vitro antihypertensive effect and production of bioactive aglycones in probiotic-fermented soymilk. Therefore, this soymilk could potentially be used as a dietary therapy to reduce the risks of hypertension and hormone-dependent diseases such as breast cancer, prostate cancer and osteoporosis.
    Matched MeSH terms: Antihypertensive Agents/pharmacology*
  16. Pharmacological mechanisms underlying the vascular activities of Loranthus ferrugineus Roxb. in rat thoracic aorta
    Ameer OZ, Salman IM, Siddiqui MJ, Yam MF, Sriramaneni RN, Mohamed AJ, et al.
    J Ethnopharmacol, 2010 Jan 8;127(1):19-25.
    PMID: 19808083 DOI: 10.1016/j.jep.2009.09.057
    The present study was aimed to investigate the pharmacological basis for the use of Loranthus ferrugineus in hypertension.
    Matched MeSH terms: Antihypertensive Agents/pharmacology*
  17. In vitro vascular effects produced by crude aqueous extract of green marine algae, Cladophora patentiramea (Mont.) Kützing, in aorta from normotensive rats
    Lim YL, Mok SL
    Med Princ Pract, 2010;19(4):260-8.
    PMID: 20516701 DOI: 10.1159/000312711
    To investigate the antihypertensive activity of aqueous extracts obtained from Malaysian coastal seaweeds and to determine the pharmacological mechanisms of the extracts on rat aorta in vitro.
    Matched MeSH terms: Antihypertensive Agents/pharmacology
  18. Future target molecules in antiglaucoma therapy: tgf-Beta may have a role to play
    Agarwal R, Agarwal P
    Ophthalmic Res, 2010;43(1):1-10.
    PMID: 19829006 DOI: 10.1159/000246571
    Glaucoma, a leading cause of irreversible blindness, is often associated with increased resistance to aqueous outflow in trabecular tissue. Increased outflow resistance has been attributed to increased extracellular matrix (ECM) deposition in trabecular tissue. A critical balance between the synthesis and breakdown of the components of extracellular tissue is important in keeping the intraocular pressure within the normal range. Multiple mechanisms have been shown to affect ECM turnover in trabecular tissue. In this review, we examine the related literature to understand the role of TGF-beta in ECM turnover, in the development and progression of glaucoma, and in possible therapeutic strategies that can be devised by targeting the TGF-beta signaling pathways.
    Matched MeSH terms: Antihypertensive Agents/pharmacology
  19. Chronic treatment with losartan and carvedilol differentially modulates renal vascular responses to sympathomimetics compared to treatment with individual agents in normal Wistar Kyoto and spontaneously hypertensive rats
    Abdulla MH, Sattar MA, Abdullah NA, Khan MA, Abdallah HH, Johns EJ
    Eur J Pharmacol, 2009 Jun 10;612(1-3):69-74.
    PMID: 19356722 DOI: 10.1016/j.ejphar.2009.03.064
    This study set out to investigate the impact of chronic cumulative blockade of angiotensin II and adrenoceptors in WKY and SHR and to explore how the renovascular responses to adrenergic and angiotensin II receptor agonists may be interdependent. Rats were treated with either losartan, carvedilol or losartan+carvedilol for 7 days and on day eight, animals were pentobarbitone anaesthetized and prepared for renal haemodynamic study. Dose-response relationships were determined in terms of reduction/elevation in the magnitude of renal blood flow in response to intrarenal arterial injection of dopamine, phenylephrine and isoprenaline. Renal vascular responses were blunted in WKY and SHR treated with either losartan or carvedilol as compared to their untreated counterparts (P<0.05). In the combined treated rats, the vascular responses to isoprenaline and phenylephrine were restored to levels observed in the untreated rats, but the renal vasoconstrictor responses to dopamine decreased (P<0.05) in both WKY and SHR. There was a reduction of (P<0.05) in the magnitude of the isoprenaline induced renal vasodilation in all SHR as compared to WKY groups. The data obtained showed that the renal vascular action of dopamine, phenylephrine and isoprenaline depended on an intact renin-angiotensin system (RAS) in WKY and SHR. Treatment with losartan or carvedilol blunted the renal vasoconstrictor/vasodilator responses to sympathomimetics which was attenuated with the combined treatment. These observations using chronic blockade of adrenergic and angiotensin receptors demonstrated that there was a long standing interdependency between the RAS and sympathetic nervous system (SNS) in determining the responsiveness of the renal vasculature of normal and hypertensive rats.
    Matched MeSH terms: Antihypertensive Agents/pharmacology*
  20. Characterization of the possible mechanisms underlying the hypotensive and spasmogenic effects of Loranthus ferrugineus methanolic extract
    Ameer OZ, Salman IM, Siddiqui MJ, Yam MF, Sriramaneni RN, Sadikun A, et al.
    Am J Chin Med, 2009;37(5):991-1008.
    PMID: 19885958
    In the present study, L. ferrugineus methanol extract (LFME) was evaluated for its blood pressure lowering effect in anesthetized normotensive Sprague Dawley (SD) rats and its spasmogenic effect in isolated guinea pig ileum. The possible mechanism(s) of action were also investigated. LFME was obtained by Soxhlet extraction. The rats were fasted overnight and anesthetized with sodium pentobarbitone (60 mg/kg i.p.). LFME was administered in i.v. boluses in the concentrations of 25, 50, 100 and 200 mg/kg respectively, with concomitant monitoring of mean arterial pressure (MAP). It was found that LFME dose-dependently reduced MAP. An i.v. bolus injection of atropine significantly decreased the blood pressure lowering effect of LFME. Similarly, L-NAME (Nomega-nitro-L-arginine methyl ester) significantly lowered both the MAP and the action duration. Conversely, no significant change in MAP was seen following i.v. injections of neostigmine, hexamethonium, prazosin and propranolol. LFME also produced a dose-dependent contractile effect in guinea pig ileum. This contraction was significantly reduced in atropine pre-incubated tissue segments, yet it was significantly enhanced in the presence of neostigmine. No appreciable change in the ability of LFME to contract guinea pig ileum was seen in the presence of hexamethonium. Accordingly, it can be postulated that LFME possesses a marked hypotensive effect that can be attributed to stimulation of muscarinic receptors and/or stimulation of nitric oxide (NO) release. Moreover, LFME retains a considerable spasmogenic action due to its cholinergic properties. The hypotensive and spasmogenic effects of LFME justify its traditional uses.
    Matched MeSH terms: Antihypertensive Agents/pharmacology*
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links