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International Journal of Biological... Feb 2016Water-soluble polysaccharide was extracted from Crassostrea gigas by hydrolysis with flavourzyme and filtered, ultrafiltered and precipitated using absolute ethanol....
Water-soluble polysaccharide was extracted from Crassostrea gigas by hydrolysis with flavourzyme and filtered, ultrafiltered and precipitated using absolute ethanol. Sugar composition analysis performed on the C. gigas polysaccharide (CGP) by high performance liquid chromatography indicated that it was comprised primarily of glucose, and its molecular weight was determined using a TSK-GEL G5000PW column to be ∼3.413×10(6) Da. Next, the antihypertensive activity of CGP was evaluated in rats. Hypertension model Wistar rats were divided into three groups and intragastrically treated with physiological saline (negative control group), CGP (treatment group), and captopril (positive control group). CGP treatment led to significant decrease in both systolic and diastolic pressures in the hypertension model Wistar rats. Furthermore, the antihypertensive effect of CGP was comparable with that of captopril. Thus, CGP has antihypertensive effects and can potentially be used as a therapeutic agent for hypertension.
Topics: Animals; Antihypertensive Agents; Blood Pressure; Crassostrea; Hypertension; Polysaccharides; Rats; Rats, Wistar; Solubility; Water
PubMed: 26642842
DOI: 10.1016/j.ijbiomac.2015.11.078 -
Cardiovascular & Hematological Agents... 2023The work aimed to study the antihypertensive ability of Haloxylon scoparium.
AIMS
The work aimed to study the antihypertensive ability of Haloxylon scoparium.
BACKGROUND
Haloxylon scoparium Pomel is used to treat various diseases, including hypertension.
OBJECTIVE
This study aimed to evaluate the antihypertensive effect of Haloxylon scoparium (H. scoparium) in hypertensive rats, and to evaluate its probable vasorelaxant activity.
MATERIALS AND METHODS
The aqueous extract of Haloxylon scoparium (AEHS) was prepared and used to investigate its antihypertensive ability in L-NAME(Nω-L-arginine methyl ester)-induced hypertensive rats, and its vasorelaxant activity was studied on the isolated thoracic aorta of rats. The acute and subchronic effects of (AEHS) on blood pressure parameters were evaluated after oral administration of AEHS (60 and 100 mg/kg body weight) for 6 h for the acute experiment and for 7 days for the subchronic test.
RESULTS
The results indicated that AEHS decreased blood pressure parameters (systolic, mean, and diastolic blood pressure) after repeated oral administration in hypertensive rats without affecting normal rats. In addition, AEHS (375-1250 μg/mL) revealed a vasorelaxant effect in thoracic aortic rings precontracted with norepinephrine (NE) (10 μM) or KCl (80 mM). This effect was partially decreased in the presence of nifedipine by inhibition of the vascular calcium channel pathway in isolated rat thoracic aorta.
CONCLUSION
The study demonstrates the beneficial effect of Haloxylon scoparium as an antihypertensive agent. Moreover, this plant exerts vasorelaxant activity via the blockade of Ca channels.
Topics: Rats; Animals; Vasodilator Agents; Antihypertensive Agents; Rats, Wistar; Plant Extracts; Hypertension
PubMed: 36017835
DOI: 10.2174/1871525720666220823163542 -
Molecules (Basel, Switzerland) Aug 2021The aerial part of Maxim. (Geraniaceae Biebersteiniaceae) known as in Chinese, has been traditionally used in Tibetan folk medicine for treatment of diabetes and...
The aerial part of Maxim. (Geraniaceae Biebersteiniaceae) known as in Chinese, has been traditionally used in Tibetan folk medicine for treatment of diabetes and hypertension. The aim of the present study was to evaluate the effects of galegine obtained from an ethanol extract of the entire plant on the rat's cardiovascular system in order to characterize its contributions as an antihypertensive agent. The antihypertensive effect of galegine was investigated in pentobarbital-anesthetized hypertensive rats at three dose levels based on the LD of galegine. Meanwhile a positive control group received dimaprit with the same procedure. Dimaprit infusion induced a significant hypotension which declined by an average margin of 20%. Simultaneously, single administration of galegine at the doses of 2.5, 5, and 10 mg/kg by intraperitoneal injection induced an immediate and dose-dependent decrease in mean arterial blood pressure (MABP) by an average margin of 40% with a rapid increase in heart rate (HR). We demonstrated that galegine is effective in reducing blood pressure in anesthetized hypertensive rats with rapid onset and a dose-related duration of the effects. The results indicate that galegine was the bioactive compound which can be used as a pharmacophore to design new hypertensive agents.
Topics: Animals; Antihypertensive Agents; Blood Pressure; Chromatography, High Pressure Liquid; Dimaprit; Female; Guanidines; Hypertension; Magnoliopsida; Male; Mice; Rats, Sprague-Dawley; Rats
PubMed: 34443434
DOI: 10.3390/molecules26164830 -
Journal of Hypertension. Supplement :... Dec 1995GUIDELINES ON DRUG SAFETY: Recent European Union draft guidelines for the safety evaluation of drugs intended for long-term use state that during drug development the... (Review)
Review
GUIDELINES ON DRUG SAFETY: Recent European Union draft guidelines for the safety evaluation of drugs intended for long-term use state that during drug development the safety profile of the new compound should be assessed over a period of time consistent with intended usage. This is in reasonable agreement with guidelines prepared by other regulatory authorities. CLINICAL DRUG DEVELOPMENT: Satisfactory preclinical data on a new compound are used to obtain authorization for human testing from the National Committees on Safety of Medicines. Clinical trials are performed in four phases, ranging from phase I studies performed on healthy volunteers (n = 20-50) to postmarketing (phase IV) studies. The latter are of great importance as they cover large patient populations (n = 2000 to > or = 10,000) and allow detection of rare adverse drug reactions. ADVERSE DRUG REACTIONS: Type B reactions are serious, unpredictable reactions to a drug that necessitate treatment withdrawal. Type A reactions are dose-dependent, and represent the majority of adverse reactions. They are often managed by dose reduction rather than drug withdrawal. ADVERSE REACTIONS TO ANTIHYPERTENSIVE AGENTS: Examples of type B adverse reactions to antihypertensives are the cutaneous and ocular reactions to practolol, and angioneurotic oedema associated with angiotensin converting enzyme inhibitors. Lacidipine, a second-generation calcium antagonist, is an example of a modern antihypertensive agent with a favourable safety profile. The adverse reactions associated with lacidipine are mild to moderate and of the A type, the major ones being those typical of calcium antagonists (headache, flushing and pedal oedema due to vasodilation.
Topics: Antihypertensive Agents; Dihydropyridines; Humans; Hypertension; Product Surveillance, Postmarketing
PubMed: 8824681
DOI: 10.1097/00004872-199512002-00002 -
Medicine and Science in Sports and... Oct 1988This review describes the effects of antihypertensive drugs on the performance of aerobic exercise. All available antihypertensive drugs lower blood pressure both at... (Review)
Review
This review describes the effects of antihypertensive drugs on the performance of aerobic exercise. All available antihypertensive drugs lower blood pressure both at rest and decrease the rate of increase during exercise. However, they differ in their effects on exercise performance. The ideal antihypertensive agent should not have significant depressant effects on the myocardium, should not promote arrhythmias, should preserve the distribution of blood flow to exercising muscle, and should not interfere with substrate utilization. Diuretics, one of the most commonly prescribed class of antihypertensives, have few deleterious effects on exercise performance but have adverse metabolic effects; beta blockers have many adverse effects on exercise performance. Agents which have the least potential for adverse effects on exercise performance and metabolic effects are the converting enzyme inhibitors, calcium channel blockers, and alpha blockers, and central alpha agonists. The literature concerning each of these drugs is reviewed and recommendations are made for prescribing for the hypertensive who wishes to engage in vigorous exercise.
Topics: Adrenergic beta-Antagonists; Angiotensin-Converting Enzyme Inhibitors; Antihypertensive Agents; Diuretics; Energy Metabolism; Exercise; Hemodynamics; Humans
PubMed: 2904108
DOI: No ID Found -
American Journal of Hypertension Feb 1991Effective antihypertensive agents have been available for the last four decades. Their use in the treatment of hypertension has resulted in a marked decline in... (Review)
Review
Effective antihypertensive agents have been available for the last four decades. Their use in the treatment of hypertension has resulted in a marked decline in hypertension-induced morbidity and mortality. There are, however, some notable shortcomings with the currently available antihypertensive therapies, including disappointing effects against coronary artery disease and the fact that, even with treatment, hypertensive patients still have considerably higher cardiovascular morbidity and mortality than matched normotensives. This may be due to insufficient lowering of the elevated arterial pressure in hypertensive patients. In theory, overtreatment may also constitute a risk, considering the J-curve phenomenon. Other factors which may play a role are the different pathophysiological mechanisms in stroke and myocardial infarction, the potentially negative metabolic effects induced by some antihypertensive drugs, the importance of cardiovascular hypertrophy (in particular, left ventricular hypertrophy), and the inability of some antihypertensive agents to reverse such changes. To rectify some of these shortcomings, a more effective antihypertensive therapy is required. Ideally, an antihypertensive agent should provide effective lowering of blood pressure, in most patients to normotensive levels, while being devoid of potentially negative metabolic effects. It should also induce reversal of the changes of cardiovascular hypertrophy and, if possible, limit tissue damage if and when a vascular complication occurs.
Topics: Antihypertensive Agents; Humans; Hypertension
PubMed: 2021456
DOI: 10.1093/ajh/4.2.84s -
Heart (British Cardiac Society) Nov 2011There are no evidence syntheses available to guide clinicians on when to titrate antihypertensive medication after initiation. (Meta-Analysis)
Meta-Analysis Review
CONTEXT
There are no evidence syntheses available to guide clinicians on when to titrate antihypertensive medication after initiation.
OBJECTIVE
To model the blood pressure (BP) response after initiating antihypertensive medication. Data sources electronic databases including Medline, Embase, Cochrane Register and reference lists up to December 2009.
STUDY SELECTION
Trials that initiated antihypertensive medication as single therapy in hypertensive patients who were either drug naive or had a placebo washout from previous drugs.
DATA EXTRACTION
Office BP measurements at a minimum of two weekly intervals for a minimum of 4 weeks. An asymptotic approach model of BP response was assumed and non-linear mixed effects modelling used to calculate model parameters.
RESULTS AND CONCLUSIONS
Eighteen trials that recruited 4168 patients met inclusion criteria. The time to reach 50% of the maximum estimated BP lowering effect was 1 week (systolic 0.91 weeks, 95% CI 0.74 to 1.10; diastolic 0.95, 0.75 to 1.15). Models incorporating drug class as a source of variability did not improve fit of the data. Incorporating the presence of a titration schedule improved model fit for both systolic and diastolic pressure. Titration increased both the predicted maximum effect and the time taken to reach 50% of the maximum (systolic 1.2 vs. 0.7 weeks; diastolic 1.4 vs. 0.7 weeks).
CONCLUSIONS
Estimates of the maximum efficacy of antihypertensive agents can be made early after starting therapy. This knowledge will guide clinicians in deciding when a newly started antihypertensive agent is likely to be effective or not at controlling BP.
Topics: Antihypertensive Agents; Blood Pressure; Drug Administration Schedule; Drug Monitoring; Humans; Hypertension; Randomized Controlled Trials as Topic; Time Factors
PubMed: 21586424
DOI: 10.1136/hrt.2010.221473 -
Bioorganic & Medicinal Chemistry Jul 20197,8-Dihydroxy-3-methyl-isochromanone-4 (XJP), is a polyphenolic natural product with moderate antihypertensive activity. To obtain new agents with stronger potency and...
7,8-Dihydroxy-3-methyl-isochromanone-4 (XJP), is a polyphenolic natural product with moderate antihypertensive activity. To obtain new agents with stronger potency and safer profile, we employed XJP and naftopidil as the lead compounds to design and synthesize a novel class of hybrids as antihypertensive agent candidates. In the present study, a series of hybrids (6a-r) of XJP bearing arylpiperazine moiety, which is identified as the pharmacophore of naftopidil, were designed and synthesized as novel α-adrenergic receptor antagonists. The biological evaluation showed that target compounds 6c, 6e, 6f, 6g, 6h, 6m and 6q possessed potent in vitro vasodilation potency and α-adrenergic receptor antagonistic activity. Furthermore, the most potent compound 6e significantly reduced the systolic and diastolic blood pressure in spontaneously hypertensive rats (SHRs), which was comparable to that of naftopidil, and it had no observable effects on the basal heart rate, suggesting that 6e deserves to be further investigated as a potential clinical candidate for the treatment of hypertension.
Topics: Animals; Antihypertensive Agents; Disease Models, Animal; Hypertension; Molecular Structure; Piperazine; Rats
PubMed: 31078380
DOI: 10.1016/j.bmc.2019.05.004 -
Drugs & Aging 2001Because of the high incidence of morbidity and mortality associated with hypertension in the elderly, the treatment of hypertension in this patient group must involve... (Review)
Review
Because of the high incidence of morbidity and mortality associated with hypertension in the elderly, the treatment of hypertension in this patient group must involve consideration of clinical, humanistic and economic outcomes. The most frequently used method of pharmacoeconomic analysis for antihypertensive therapy involves cost-effectiveness analysis, although several other methods are available. Current evidence reveals a trend toward cost effectiveness of antihypertensive treatment in elderly patients. However, these formal analyses are limited by the need for extrapolation of data regarding efficacy and level of risk from epidemiological and randomised trials, information which is often lacking. To incorporate economic factors into clinical decision making, other measures of economic impact should be explored. The economic impact of antihypertensive therapy is affected by the level of risk for the patient and the efficacy of the treatment. Data indicate that the risk of morbidity and mortality related to hypertension increases with age and that current antihypertensive drugs reduce this risk. When choosing an antihypertensive agent, the following parameters should be considered: acquisition cost, likelihood of adverse effects and other determinants of treatment adherence, and individual predictors of response. The economic outcomes will be maximised if prudent drug selection is supplemented by appropriate diagnostic and classification procedures and reduction of cardiovascular risk factors other than hypertension. The accumulation of data addressing the risks and benefits of therapy for the very old and the comparative efficacy of newer antihypertensive therapies will further clarify the decision-making process.
Topics: Aged; Antihypertensive Agents; Economics, Pharmaceutical; Health Care Costs; Humans; Hypertension; Morbidity; Risk Factors
PubMed: 11482745
DOI: 10.2165/00002512-200118070-00005 -
Journal of Hypertension May 1998Effective antihypertensive treatment has prevented target-organ involvement in hypertension, markedly reducing morbidity and mortality from strokes, coronary heart... (Review)
Review
BACKGROUND
Effective antihypertensive treatment has prevented target-organ involvement in hypertension, markedly reducing morbidity and mortality from strokes, coronary heart disease, cardiac failure, and hypertensive emergencies. However, the incidence of hypertension-related end-stage renal disease continues to increase, suggesting that therapeutic reduction in arterial pressure by itself is not sufficient to prevent the development of hypertensive renal failure.
OBJECTIVE
To examine experimental and clinical data concerning the protective effect of reduction of arterial pressure on the progression of hypertension-related renal disease, and the evidence indicating that some antihypertensive agents may afford more nephroprotection, over and above that attributable to reduction of arterial pressure.
RESULTS
Results of numerous studies clearly indicate that adequate control of arterial pressure, irrespective of the antihypertensive agent used, slowed the progression of renal disease. Results of some studies suggest that lowering arterial pressure below the level that is usually considered adequate has an additional beneficial effect by slowing the progression of renal injury.
CONCLUSION
Results of a number of studies evaluating nephroprotective effects of various drugs and regimens have indicated that certain agents, most notably angiotensin converting enzyme inhibitors and their combination with calcium antagonists, afford more protection than do others at similar levels of reduction of arterial pressure. Results of still other studies suggest that certain agents that exert greater nephroprotection are more efficient at controlling arterial pressure. Therefore, further data are needed before any final conclusion can be drawn. However, it is clear that, in order to establish nephroprotection in patients with essential hypertension, the problem should not be further complicated by additional comorbid diseases such as diabetes mellitus.
Topics: Animals; Antihypertensive Agents; Blood Pressure; Humans; Hypertension; Kidney
PubMed: 9797165
DOI: 10.1097/00004872-199816050-00001