Chromosomal aberrations and sister chromatid exchanges in lymphocytes and urine mutagenicity of migraine patients: a comparison of chronic feverfew users and matched non-users

Feverfew for preventing migraine

BACKGROUND

This review is an update of a previously published review in the Cochrane Database of Systematic Reviews on 'Feverfew for preventing migraine' (2004, Issue 1). Feverfew (Tanacetum parthenium L.) extract is a herbal remedy, which has been used for preventing attacks of migraine.

OBJECTIVES

To systematically review the evidence from double-blind randomised controlled trials (RCTs) assessing the clinical efficacy and safety of feverfew monopreparations versus placebo for preventing migraine.

SEARCH METHODS

For this updated version of the review we searched CENTRAL, MEDLINE, EMBASE and AMED to January 2015. We contacted manufacturers of feverfew and checked the bibliographies of identified articles for further trials.

SELECTION CRITERIA

We included randomised, placebo-controlled, double-blind trials assessing the efficacy of feverfew monopreparations for preventing migraine in patients of any age. We included trials using clinical outcome measures, while we excluded trials focusing exclusively on physiological parameters. There were no restrictions regarding the language of publication.

DATA COLLECTION AND ANALYSIS

We systematically extracted data on patients, interventions, methods, outcome measures, results and adverse events. We assessed risk of bias using the Cochrane 'Risk of bias' tool and evaluated methodological quality using the Oxford Quality Scale developed by Jadad and colleagues. Two review authors (BW and MHP for this update, MHP and EE for the original version) independently selected studies, assessed methodological quality and extracted data. We resolved disagreements concerning evaluation of individual trials through discussion.

MAIN RESULTS

We identified one new study for this update, resulting in six trials (561 patients) meeting the inclusion criteria. Five of the six trials reported on the main outcome, migraine frequency. Although five of the trials were generally of good methodological quality, all studies were either of unclear or high risk of bias with regards to sample size. Pooled analysis of the results was not possible due to the lack of common outcome measures and heterogeneity between studies in terms of participants, interventions and designs.The most recent trial added to this version of the review is rigorous and larger (n = 218), using a stable feverfew extract at a dose determined by a previous dose-finding trial. It reports that feverfew reduced migraine frequency by 1.9 attacks from 4.8 to 2.9 and placebo by 1.3 from to 4.8 to 3.5 per month, resulting in a difference in effect between feverfew and placebo of 0.6 attacks per month. For the secondary outcome measures intensity and duration of migraine attacks, incidence and severity of nausea and vomiting, and global assessment no statistically significant differences were reported. Results of previous trials are not convincing: three trials reporting positive effects of feverfew are all of small sample size (17 to 60 participants), while two rigorous trials (n = 50, 147) did not find significant differences between feverfew and placebo. Only mild and transient adverse events, most commonly gastrointestinal complaints and mouth ulcers, were reported in the included trials.

AUTHORS' CONCLUSIONS

Since the last version of this review, one larger rigorous study has been included, reporting a difference in effect between feverfew and placebo of 0.6 attacks per month. This adds some positive evidence to the mixed and inconclusive findings of the previous review. However, this constitutes low quality evidence, which needs to be confirmed in larger rigorous trials with stable feverfew extracts and clearly defined migraine populations before firm conclusions can be drawn. It appears from the data reviewed that feverfew is not associated with any major safety concerns.

Feverfew (Tanacetum parthenium L.): A systematic review

Feverfew (Tanacetum parthenium L.) (Asteraceae) is a medicinal plant traditionally used for the treatment of fevers, migraine headaches, rheumatoid arthritis, stomach aches, toothaches, insect bites, infertility, and problems with menstruation and labor during childbirth. The feverfew herb has a long history of use in traditional and folk medicine, especially among Greek and early European herbalists. Feverfew has also been used for psoriasis, allergies, asthma, tinnitus, dizziness, nausea, and vomiting. The plant contains a large number of natural products, but the active principles probably include one or more of the sesquiterpene lactones known to be present, including parthenolide. Other potentially active constituents include flavonoid glycosides and pinenes. It has multiple pharmacologic properties, such as anticancer, anti-inflammatory, cardiotonic, antispasmodic, an emmenagogue, and as an enema for worms. In this review, we have explored the various dimensions of the feverfew plant and compiled its vast pharmacologic applications to comprehend and synthesize the subject of its potential image of multipurpose medicinal agent. The plant is widely cultivated to large regions of the world and its importance as a medicinal plant is growing substantially with increasing and stronger reports in support of its multifarious therapeutic uses.

Biological activity of plant extracts: novel analgesic drugs

The plant-derived secondary metabolites have, over the years, greatly contributed to our current understanding of the important mechanisms related to the process of pain transmission and treatment. Furthermore, they have permitted us to characterise receptor types and identify endogenous ligands involved in the mechanism of nociception. In this review, we discuss the recent advances that have occurred regarding plant-derived substances in the process of development of new analgesic drugs. Plants, such as Papaver somniferum, Cannabis sativa and those of the Capsicum and Salix species, have greatly accounted for the development of clinically relevant drugs which are useful for the management of pain disorders. The recent advances in our understanding of the mechanisms of action of the above plant-derived substances, together with use of molecular biology techniques, have greatly accelerated attempts to identify promising targets for the discovery of new, safe and efficient analgesic drugs. Despite the great progress which has occurred in the elucidation of pain transmission and despite decades of use, leaving aside its known undesirable sides effects, morphine continues to be one of the most used drugs in clinical practice for the treatment of pain disorders. Thus, safer and more efficacious analgesic drugs are urgently needed. A search through the literature reveals that many potentially active antinociceptive plant-derived compounds have been identified. However, studies aiming to investigate their cellular and molecular mechanisms of action and well-controlled clinical trials to prove their efficacy in humans are still lacking. Nevertheless, natural or synthetic substances that bind to vanilloid or cannabinoid receptors, or even those that are capable of modulating the endogenous ligands which bind to these receptors, are expected to soon appear to assist in the treatment of several pain disorders, including those of neuropathic or neurogenic origin.

Feverfew for preventing migraine

BACKGROUND

Feverfew (Tanacetum parthenium L.) extract is a herbal remedy used for preventing attacks of migraine.

OBJECTIVES

To systematically review the evidence from double-blind randomised controlled trials (RCTs) assessing the clinical efficacy and safety of feverfew versus placebo for preventing migraine.

SEARCH STRATEGY

Publications describing (or which might describe) double-blind RCTs of feverfew extract for migraine were sought through the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 2, 2003); PREMEDLINE/MEDLINE (1966 to July 2003); EMBASE (1974 to July 2003); the trials register of the Cochrane Pain, Palliative and Supportive care group (July 2003); and AMED (1985 to July 2003). Manufacturers of feverfew were contacted and the bibliographies of identified articles checked for further trials.

SELECTION CRITERIA

Randomised, placebo-controlled, double-blind trials assessing the efficacy of feverfew for preventing migraine were included. Trials using clinical outcome measures were included. Trials focusing exclusively on physiological parameters were excluded. There were no restrictions regarding the language of publication.

DATA COLLECTION AND ANALYSIS

Data on patients, interventions, methods, outcome measures, results and adverse events were extracted systematically. Methodological quality was evaluated using the scoring system developed by Jadad and colleagues. Two reviewers independently selected studies, assessed methodological quality and extracted data. Disagreements concerning evaluation of individual trials were resolved through discussion.

MAIN RESULTS

Five trials (343 patients) met the inclusion criteria. Results from these trials were mixed and did not convincingly establish that feverfew is efficacious for preventing migraine. Only mild and transient adverse events were reported in the included trials.

REVIEWER'S CONCLUSIONS

There is insufficient evidence from randomised, double-blind trials to suggest an effect of feverfew over and above placebo for preventing migraine. It appears from the data reviewed that feverfew presents no major safety problems.

Inhibitory effect of herbal remedies on 12-O-tetradecanoylphorbol-13-acetate-promoted Epstein-Barr virus early antigen activation

For the past several years we have been evaluating natural products as potential cancer chemopreventive agents in a short term in vitro assay involving Epstein--Barr virus early antigen (EBV-EA) activation in Raji cells promoted by phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA). Because of the current interest in the use of herbal remedies, we considered examining them for their cancer chemopreventive activities, using their extracts with a view to uncovering such benefits (if any) these remedies might possess. Thirty-six extracts of 32 herbs belonging to 27 families in use as herbal remedies including those of gingko, black cohosh, echinacea, kava-kava, saw palmetto, turmeric, angelica, wild yam, cat's claw, passion flower, muira puama, feverfew, blueberry, chasteberry, licorice, nettle, golden seal, pygeum, ginger, valerian and hops were prepared and evaluated. Turmeric at a concentration of 10 microg x ml (-1)exhibited the most potent anti-EBV-EA activity, which is ten times more than passionflower, that is next in the order of activity. At the concentration level of 100 microg ml (-1), several of the herbal remedies tested inhibited the EBV-EA in Raji cells exposed to the tumor promoter TPA (32 pM) by more than 90%. We also report for the first time the activities of 16 new medicinal plants as potential cancer chemopreventive agents. Since inhibitors of EBV-EA promoted by TPA in vitro have been shown to be effective anti-tumor promoting agents in laboratory animal models, our results indicate new and potential applications of these herbal remedies as cancer chemopreventive agents since they are already in clinical use in the human population.

The efficacy and safety of feverfew (Tanacetum parthenium L.): an update of a systematic review

OBJECTIVE

Feverfew (Tanacetum parthenium L.) is a popular herbal remedy often advocated for the prevention of migraine. The aims of this systematic review are to update the evidence from rigorous clinical trials for or against the efficacy of feverfew for migraine prevention and to provide a safety profile of this herbal remedy.

DESIGN

Literature searches were performed using the following databases: Medline, Embase, Biosis, CISCOM and the Cochrane Library (all from their inception to December 1999). Only randomized, placebo-controlled, double-blind trials of feverfew mono-preparations for the prevention of migraine in human subjects were included. All articles were read by two independent reviewers. Data were extracted in a pre-defined, standardized fashion. The methodological quality of the trials was evaluated by the Jadad score. For the assessment of safety issues, major reference texts were also consulted.

RESULTS

Six trials met the inclusion/exclusion criteria. The majority favour feverfew over placebo. Yet important caveats exist. The data also suggest that feverfew is associated with only mild and transient adverse effects and few other safety concerns.

CONCLUSIONS

Feverfew is likely to be effective in the prevention of migraine. There are no major safety problems.

Feverfew for preventing migraine

BACKGROUND

Feverfew (Tanacetum parthenium L.) is a popular herbal remedy for migraine.

OBJECTIVES

To systematically review the evidence for or against the efficacy of feverfew versus placebo for the prevention of migraine.

SEARCH STRATEGY

Electronic literature searches were performed using the databases CISCOM (Research Council for Complementary Medicine, London, UK), MEDLINE, EMBASE, Biosis and the Cochrane Library (each from its inception to April 1998). Manufacturers were contacted and the bibliographies of identified articles checked for further trials.

SELECTION CRITERIA

Randomised, placebo-controlled, double-blind trials assessing the efficacy of feverfew for preventing migraine were included. No restrictions regarding the language of publication were imposed.

DATA COLLECTION AND ANALYSIS

Data on patients, interventions, methods, outcomes and results were extracted in a pre-defined, standardised manner. Methodological quality was evaluated using the scoring system developed by Jadad and colleagues. Both data extraction and the assessment of methodological quality were performed independently by two reviewers.

MAIN RESULTS

Four trials met the inclusion criteria. The majority of these trials suggested beneficial effects of feverfew compared with placebo. However, the trial with the highest methodological quality, which was also among the largest, found no significant difference between feverfew and placebo.

REVIEWER'S CONCLUSIONS

The efficacy of feverfew for the prevention of migraine has not been established beyond reasonable doubt.