Promising hypotensive effect of hawthorn extract: a randomized double-blind pilot study of mild, essential hypertension

Radioprotective effects of Hawthorn against genotoxicity induced by gamma irradiation in human blood lymphocytes

The radioprotective effect of hawthorn (Crataegus microphylla) fruit extract was investigated in cultured blood lymphocytes from human volunteers. Peripheral blood samples were collected from five human volunteers 10 min before and 1, 2 and 3 h after a single oral ingestion of 500 mg hawthorn powder extract. At each time point, the whole blood was exposed in vitro to 150 cGy of cobalt-60 gamma irradiation, and then the lymphocytes were cultured with mitogenic stimulation to determine the micronuclei in cytokinesis-blocked binucleated cell. The lymphocytes in the blood samples collected after extract ingestion exhibited a significant decrease in the incidence of binucleated cells containing micronuclei as compared to similarly irradiated lymphocytes collected prior to extract ingestion. The maximum decrease in the frequency of micronuclei-containing cells was observed at 1 h after ingestion of Hawthorn extract (on average a 44% decrease). These data suggest that it may be possible to use Hawthorn extracts in personnel exposed to radiation in order to protect lymphocytes from radiation effects.

Herbal medicines in the treatment of psychiatric disorders: a systematic review

This paper reports a critical review of 27 herbal medicines and formulas in treating a broad range of psychiatric disorders (in addition to anxiety and depression), including obsessive-compulsive, seasonal affective, bipolar depressive, psychotic, phobic and somatoform disorders. Ovid Medline, Pubmed and the Cochrane Library were searched for pharmacological and clinical evidence of herbal medicines with psychotropic activity. A forward search of later citations was also conducted. Whilst substantial high-quality evidence exists for the use of kava and St John's wort in the treatment of anxiety and depression respectively, currently there is insufficient robust clinical evidence for the use of many other herbal medicines in psychiatric disorders. Phytotherapies which potentially have significant use in psychiatry, and urgently require more research are Rhodiola rosea (roseroot) and Crocus sativus (saffron) for depression; Passiflora incarnata (passionflower), Scutellaria lateriflora (scullcap) and Zizyphus jujuba (sour date) for anxiety disorders; and Piper methysticum (kava) for phobic, panic and obsessive-compulsive disorders. While depression and anxiety are commonly researched, the efficacy of herbal medicines in other mental disorders requires attention. The review addresses current issues in herbal psychotherapy: herbal safety, future areas of application, the relationship of herbal medicine with pharmaceuticals and the potential prescriptive integration of phytomedicines with synthetic psychotropic medicines. Particular attention is given to clinical and safety issues with St John's wort and kava.

The Natural Treatment of Hypertension

The goal of this review is to evaluate the efficacy of commonly available dietary supplements in the treatment of hypertension, using the average blood pressure reduction achieved with the implementation of lifestyle modifications as a standard. For this reason, the authors focus on the antihypertensive potential of these agents rather than pharmacology, pharmacokinetics, adverse effects, or supplement-drug interactions. For the purpose of this review, dietary supplements are defined as exhibiting some evidence of benefit if a systolic blood pressure reduction of 9.0 mm Hg or greater and/or a diastolic blood pressure reduction of 5.0 mm Hg or greater has been observed in previously published, peer-reviewed trials. These defining limits are based on the average blood pressure reduction associated with the implementation of certain lifestyle modifications. Agents with some evidence of benefit include coenzyme Q10, fish oil, garlic, vitamin C, and L-arginine.

Simultaneous determination of vitexin-4″-O-glucoside and vitexin-2″-O-rhamnoside from hawthorn leaves flavonoids in rat plasma by HPLC method and its application to pharmacokinetic studies

The present study was to investigate the pharmacokinetics of the two similar flavonoid glycosides, vitexin-4''-O-glucoside (VGL) and vitexin-2''-O-rhamnoside (VRH) in rats after intravenous administration of hawthorn leaves flavonoids (HLF). Blood samples were collected via tail vein at time intervals after drug administration and the plasma concentrations of the studied ingredients were analyzed by HPLC after the plasma protein was precipitated directly with methanol. VGL and VRH were successfully separated using a C(18) column with a UV detection at 330 nm and a mobile phase of methanol-acetonitrile-tetrahydrofuran-0.5% acetic acid (1:1:19.4:78.6, v/v/v/v). The assay linearities of VGL and VRH were confirmed over the range 0.23-138.42 and 0.36-218.49 microg/ml, respectively. The accuracy and precision of the two analytes at high, medium and low concentration were within the range of -3.13% to 3.51% and below 4%, the mean assay recoveries of them (n=5) ranged from 96.87% to 101.75% and 96.88% to 103.51% for intra- and inter-day assays and the mean extraction recoveries of them (n=5) varied from 92.68% to 95.74% for VGL and 93.45% to 99.26% for VRH, respectively. After intravenous administration of HLF to rats over the doses range of 10-40 mg/kg, the plasma concentration--time curves of VGL and VRH were both conformed to the three-compartment open pharmacokinetic model and linear pharmacokinetic characteristics.

Herbal medicine: the science of the art

In the last 50 years science has provided new perspectives on the ancient art of herbal medicine. The present article discusses ways in which the evidence base for the professional use of 'Western' herbal medicine, as therapy to treat disease, known as phytotherapy, can be strengthened and developed. The evidence base for phytotherapy is small and lags behind that for the nutritional sciences, mainly because phytochemicals are ingested as complex mixtures that are incompletely characterised and have only relatively recently been subject to scientific scrutiny. While some methodologies developed for the nutritional sciences can inform phytotherapy research, opportunities for observational studies are more limited, although greater use could be made of patient case notes. Randomised clinical trials of single-herb interventions are relatively easy to undertake and increasing numbers of such studies are being published. Indeed, enough data are available on three herbs (ginkgo (Ginkgo biloba), St John's wort (Hypericum perforatum) and saw palmetto (Serenoa repens)) for meta-analyses to have been undertaken. However, phytotherapy is holistic therapy, using lifestyle advice, nutrition and individually-prescribed mixtures of herbs aimed at reinstating homeostasis. While clinical experience shows that this approach is applicable to a wide range of conditions, including chronic disease, evidence of its efficacy is scarce. Strategies for investigating the full holistic approach of phytotherapy and its main elements are discussed and illustrated through the author's studies at the University of Reading.

Dietary Supplements for The Prevention and Treatment of Coronary Artery Disease

PURPOSE

With the recent growth in the use of dietary supplements, it is increasingly important for clinicians to be familiar with the evidence for and against their efficacy. We set out to systematically review the dietary supplements available for the prevention and treatment of coronary artery disease.

METHODS

Between May 2004 and May 2006, we searched MEDLINE, the Cochrane Library, and Pro-Quest using the MeSH terms hypertension, hypercholesterolemia, myocardial infarction, dietary supplements, and herb-drug interactions. The MeSH terms of individual supplements identified were then added to the search. Reference lists of pertinent papers were also searched to find appropriate papers for inclusion. We included randomized controlled trials published in English of at least 1 week's duration that studied the efficacy of supplements in the treatment of hypercholesterolemia, or hypertension, or in the prevention of cardiac events. Qualifying papers were identified and assigned a Jadad quality score. In areas of uncertainty, a second investigator independently scored the trial.

RESULTS

Fifteen (15) supplements were identified. Of these, most had little data available and most of the data were of poor quality. The supplements with the most supporting data were policosanol and garlic, both for hyperlipidemia.

CONCLUSIONS

A growing body of literature exists for numerous supplements in the prevention of coronary artery disease, but much of these data are inconclusive. Clinicians should become familiar with the extent and limitations of this literature so that they may counsel their patients better.

Effect of hawthorn (Crataegus oxycantha) crude extract and chromatographic fractions on multiple activities in a cultured cardiomyocyte assay

Extracts of hawthorn (Crataegus oxycantha) have become popular herbal supplements for their well-recognized cardiotonic effects. Many commercial preparations have been used successfully in the treatment of congestive heart failure, although the active principles within these extracts have yet to be conclusively identified. Several hawthorn preparations were studied and found to have negative chronotropic effects in a cultured neonatal murine cardiomyocyte assay using unpaced cells. As compared to conventional cardiac drugs (i.e., epinephrine, milrinone, ouabain, or propranolol), hawthorn extract has a unique activity profile. Hawthorn extract appears to be anti-arrhythmic and capable of inducing rhythmicity in quiescent cardiomyocytes. Hawthorn extract does not cause beta-adrenergic receptor blockade at concentrations which cause negative chronotropic effects. Commercial hawthorn preparations, extracts prepared from dried leaves and those made from dried berries have similar chronotropic activities. When crude extracts are separated using size-exclusion chromatography, several fractions retain multiple cardiac activities. Assays with chromatographic fractions reveal that multiple dissimilar cardioactive components may exist within the extract, making the identification of individual active constituents more challenging.

Magnesium supplementation for the management of essential hypertension in adults

BACKGROUND

Epidemiological evidence on the effects of magnesium on blood pressure is inconsistent. Metabolic and experimental studies suggest that magnesium may have a role in the regulation of blood pressure.

OBJECTIVES

To evaluate the effects of magnesium supplementation as treatment for primary hypertension in adults.

SEARCH STRATEGY

We searched the Cochrane Library, MEDLINE, EMBASE, Science Citation Index, ISI Proceedings, ClinicalTrials.gov, Current Controlled Trials, CAB abstracts, and reference lists of systematic reviews, meta-analyses and randomised controlled trials (RCTs) included in the review.

SELECTION CRITERIA

Inclusion criteria were: 1) RCTs of a parallel or crossover design comparing oral magnesium supplementation with placebo, no treatment, or usual care; 2) treatment and follow-up >/=8 weeks; 3) participants over 18 years old, with raised systolic blood pressure (SBP) >/=140 mmHg or diastolic blood pressure (DBP) >/=85 mmHg; 4) SBP and DBP reported at end of follow-up. We excluded trials where: participants were pregnant; received antihypertensive medication which changed during the study; or magnesium supplementation was combined with other interventions.

DATA COLLECTION AND ANALYSIS

Two reviewers independently abstracted data and assessed trial quality. Disagreements were resolved by discussion or a third reviewer. Random effects meta-analyses and sensitivity analyses were conducted.

MAIN RESULTS

Twelve RCTs (n=545) with eight to 26 weeks follow-up met our inclusion criteria. The results of the individual trials were heterogeneous. Combining all trials, participants receiving magnesium supplements as compared to control did not significantly reduce SBP (mean difference: -1.3 mmHg, 95% CI: -4.0 to 1.5, I(2)=67%), but did statistically significantly reduce DBP (mean difference: -2.2 mmHg, 95% CI: -3.4 to -0.9, I(2)=47%). Sensitivity analyses excluding poor quality trials yielded similar results. Sub-group analyses and meta-regression indicated that heterogeneity between trials could not be explained by dose of magnesium, baseline blood pressure or the proportion of males among the participants.

AUTHORS' CONCLUSIONS

In view of the poor quality of included trials and the heterogeneity between trials, the evidence in favour of a causal association between magnesium supplementation and blood pressure reduction is weak and is probably due to bias. This is because poor quality studies generally tend to over-estimate the effects of treatment. Larger, longer duration and better quality double-blind placebo controlled trials are needed to assess the effect of magnesium supplementation on blood pressure and cardiovascular outcomes.

Crataegus Special Extract WS® 1442 Induces an Endothelium-Dependent, NO-mediated Vasorelaxation via eNOS-Phosphorylation at Serine 1177

PURPOSE

This study investigates the influence of WS(R) 1442, a special extract of Crataegus leaves with flowers, on the relaxation of rat aorta and human mammarian artery (coronary bypass patients).

METHODS

Experiments were performed in the presence and absence (mechanical disruption) of endothelium. In addition, we investigated three fractions of WS(R) 1442 (fraction A: lipophilic, containing flavonoids and oligomeric procyanidins (OPC), fraction B: hydrophilic, containing flavonoids and low molecular weight OPC, fraction C: hydrophilic, essentially flavonoid-free and rich in high molecular weight OPC).

RESULTS

WS 1442 induced a concentration-dependent vasodilation in isolated vessel rings that had been precontracted by 10 microM phenylephrine (concentration for halfmaximal relaxation (IC(50)): rat: 15.1 +/- 0.6 microg/ml (n = 7), human: 19.3 +/- 3.4 microg/ml (n = 6)). The maximal vasorelaxation induced after application of 100 microg of WS 1442 was 75.0 +/- 5.7% (rat) and 79.2 +/- 5.8% (human) of the papaverine (0.1 mM)-induced vasodilation. If the experiments were performed in the presence of L-nitroarginine methylester (10 microM, eNOS-inhibition) or after mechanical disruption of the endothelium, no vasorelaxation was observed in the presence of WS 1442. The vasorelaxant properties of WS 1442 were mediated by fraction C. WS 1442 induced an NO-liberation from human coronary artery endothelial cells as measured by diaminofluorescein. WS 1442 induced eNOS-activation was due to a phosphorylation at serine 1177. No eNOS-translocation or phosphorylation at serine 114 or threonine 495 was observed after application of WS 1442.

CONCLUSIONS

It is concluded that WS 1442, induces an endothelium-dependent, NO-mediated vasorelaxation via eNOS phosphorylation at serine 1177.

Lifestyle interventions to reduce raised blood pressure: a systematic review of randomized controlled trials

PURPOSE

To quantify effectiveness of lifestyle interventions for hypertension.

DATA SOURCES

Electronic bibliographic databases from 1998 onwards, existing guidelines, systematic reviews.

STUDY SELECTION AND DATA ABSTRACTION

We included randomized, controlled trials with at least 8 weeks' follow-up, comparing lifestyle with control interventions, enrolling adults with blood pressure at least 140/85 mmHg. Primary outcome measures were systolic and diastolic blood pressure. Two independent reviewers selected trials and abstracted data; differences were resolved by discussion.

RESULTS

We categorized trials by type of intervention and used random effects meta-analysis to combine mean differences between endpoint blood pressure in treatment and control groups in 105 trials randomizing 6805 participants. Robust statistically significant effects were found for improved diet, aerobic exercise, alcohol and sodium restriction, and fish oil supplements: mean reductions in systolic blood pressure of 5.0 mmHg [95% confidence interval (CI): 3.1-7.0], 4.6 mmHg (95% CI: 2.0-7.1), 3.8 mmHg (95% CI: 1.4-6.1), 3.6 mmHg (95% CI: 2.5-4.6) and 2.3 mmHg (95% CI: 0.2-4.3), respectively, with corresponding reductions in diastolic blood pressure. Relaxation significantly reduced blood pressure only when compared with non-intervention controls. We found no robust evidence of any important effect on blood pressure of potassium, magnesium or calcium supplements.

CONCLUSIONS

Patients with elevated blood pressure should follow a weight-reducing diet, take regular exercise, and restrict alcohol and salt intake. Available evidence does not support relaxation therapies, calcium, magnesium or potassium supplements to reduce blood pressure.

Adverse-Event Profile of Crataegus Spp

Crataegus spp. (hawthorn) monopreparations are predominantly used for treating congestive heart failure. The effectiveness of hawthorn preparations (flowers with leaves; berries) is documented in a number of clinical studies, reviews and meta-analyses. The aim of this article is to assess the safety data of all available human studies on hawthorn monopreparations. Systematic searches were conducted on MEDLINE, EMBASE, AMED, The Cochrane Library, the UK National Research Register and the US ClinicalTrials.gov (up to January 2005). Data were requested from the spontaneous reporting scheme of the WHO. Hand searches were also conducted in a sample of relevant medical journals, conference proceedings, reference lists of identified articles and our own files. Eight manufacturers of hawthorn-containing preparations were contacted and asked to supply any information on adverse events or drug interactions. Data from all clinical studies and reports were assessed. Only human studies on monopreparations were included. Data from hawthorn-containing combination preparations and homeopathic preparations were excluded. All studies were read and evaluated by one reviewer and independently verified by at least one additional reviewer.Twenty-nine clinical studies were identified, of which 24 met our inclusion criteria. A total of 7311 patients were enrolled, and data from 5,577 patients were available for analysis. The daily dose and duration of treatment with hawthorn monopreparations ranged from 160 to 1,800 mg and from 3 to 24 weeks, respectively. The extracts most used in the clinical trials were WS 1,442 (extract of hawthorn standardised to 18.75% oligomeric procyanidins) and LI 132 (extract of hawthorn standardised to 2.25% flavonoids). Overall, 166 adverse events were reported. Most of these adverse events were, in general, mild to moderate; eight severe adverse events have been reported with the LI 132 extract. The most frequent adverse events were dizziness/vertigo (n = 15), gastrointestinal complaints (n = 24), headache (n = 9), migraine (n = 8) and palpitation (n = 11). The WHO spontaneous reporting scheme received 18 case reports. In the identified trials, the most frequent adverse events were dizziness (n = 6), nausea (n = 5), fall (n = 2), gastrointestinal haemorrhage (n = 2), circulation failure (n = 2) and erythematous rash (n = 2). There were no reports of drug interactions. In conclusion, all data reviewed in this article seem to indicate that hawthorn is well tolerated even if some severe adverse events were reported; this suggests that further studies are needed to better assess the safety of hawthorn-containing preparations. Moreover, the unsupervised use of this drug can be associated with problems, especially if given with concomitant medications.

Effects of Natural Health Products on Blood Pressure

OBJECTIVE:

To review the scientific literature to identify reports of the effects of natural health products (NHPs) on blood pressure. DATA SOURCES: Electronic databases (MEDLINE [1965–May 2004] via PubMed, the Cochrane Library [1995–May 2004], International Pharmaceutical Abstracts [1970–May 2004], Iowa Drug Information Services [1965–May 2004]) were searched using the key words medicine, herbal plants, medicinal plant preparations, phytotherapy, angiosperms/therapeutic use, gymnosperms/therapeutic use, ethnopharmacology, pharmacognosy, blood pressure, hypertension, hypotension, and diuretic. Searches were not limited by date, language, or publication type. Review articles and texts, as well as reference lists of relevant articles, were used to identify additional reports.

STUDY SELECTION AND DATA EXTRACTION:

Articles (English-language after 1980) were assigned to the following categories: human study, case report, animal study, in vitro study, or theoretical prediction based on chemical constituents. Discussions of mechanisms of action were noted.

DATA SYNTHESIS:

A comprehensive search of the scientific literature identified NHPs capable of affecting blood pressure. Case reports and clearly defined mechanisms of action provided strong evidence for the ability of ephedra and licorice to increase blood pressure. Coenzyme Q10 was reported to decrease systolic and diastolic blood pressure, although the mechanism is unclear. The clinical significance of the blood pressure effects of other NHPs is unclear due to lack of conclusive in vivo data, as well as substantial variability in the chemical content of preparations of NHPs.

CONCLUSIONS:

Among published information, there is little definitive evidence with regard to the impact of NHPs on blood pressure. Additionally, effects may vary in a given patient with the formulation and standardization of a particular product. Until research better characterizes the effect of NHPs on blood pressure, patients should be encouraged to talk with their healthcare provider before starting or stopping any herbal product.

1- and 2-substituted naphthalenes: a new class of potential hypotensive agents

A series of 2-substituted aminomethyloxy naphthalenes 1 and 4-(1-naphthoxy-2-substituted aminomethyl)-butanoic acids 2 were synthesized by Mannich reaction of 4-(2-naphthoxy)-butanoic acid 3 and 4-(1-naphthoxy)-butanoic acid 4 with appropriate secondary amines and para-formaldehyde. The newly synthesized compounds were tested for their hypotensive activity at 5 mg/kg i.v. dose in cats. The results indicated that the analogue 2-(N4-phenyl-N1-piperazino)-methyloxy naphthalene 1d (> N = N4-phenyl-N1-piperazino) was the most active analogue when its hypotensive activity was compared to the reference compound propranolol.

Double-blind, randomised, placebo-controlled study to evaluate the efficacy and safety of a fixed combination containing two plant extracts (Crataegus oxyacantha and Eschscholtzia californica) and magnesium in mild-to-moderate anxiety disorders

OBJECTIVE

To assess the clinical efficacy of a neurotonic component containing fixed quantities of two plant extracts (Crataegus oxyacantha and Eschscholtzia californica) and magnesium versus placebo in mild-to-moderate anxiety disorders with associated functional disturbances, under usual general practice prescription conditions.

RESEARCH DESIGN AND METHODS

A total of 264 patients (81% female; mean age: 44.6 years) presenting with generalised anxiety (DSM-III-R) of mild-to-moderate intensity (total Hamilton anxiety scale score between 16 and 28) were included in a double-blind, randomised, placebo-controlled trial. Patients were randomly assigned to two groups: 130 received the study drug (Sympathyl), and 134 a placebo (two tablets twice daily for 3 months). Efficacy and safety data were recorded before first administration and 7, 14, 30, 60 and 90 days after start of treatment.

MAIN OUTCOME MEASURES

Efficacy was assessed by (a) change in Hamilton anxiety scale total and somatic scores; (b) change in patient self-assessment; (c) number and percentage of responsive subjects (reduction of at least 50% in Hamilton or self-assessment score); and (d) the physician's clinical global impression. Tolerance was assessed by undesirable events spontaneously reported by the patients over the study period.

RESULTS

Total and somatic Hamilton scale scores and subjective patient-rated anxiety fell during treatment, indicating clinical improvement. The decrease was greater in the study drug than in the placebo group. End of treatment clinical improvement, as measured by the mean difference between final and pre-treatment scores, was, for the study drug and placebo groups respectively: -10.6 and -8.9 on the total anxiety score (p = 0.005); -6.5 and -5.7 on the somatic score (p = 0.054); and -38.5 and -29.2 for subjectively assessed anxiety (p = 0.005). The risk/benefit ratio as judged by the investigating physicians was also significantly greater in the study drug than in the placebo group. In all, 15 patients (11.5%) in the study drug group and 13 patients (9.7%) in the placebo group experienced 22 and 15 adverse events, respectively. Undesirable events were mainly mild or moderate digestive or psychopathological disorders.

CONCLUSIONS

The preparation containing fixed quantities of Crataegus oxyacantha, Eschscholtzia californica, and magnesium proved safe and more effective than placebo in treating mild-to-moderate anxiety disorders. Sympathyl is produced and marketed by Laboratoire Innotech International, Arcueil, France.