Butterbur, a herbal remedy, confers complementary anti-inflammatory activity in asthmatic patients receiving inhaled corticosteroids

A review on the ethnobotany, phytochemistry, pharmacology and toxicology of butterbur species (Petasites L.)

ETHNOPHARMACOLOGICAL RELEVANCE

Petasites (butterbur, Asteraceae) species have been used since Ancient times in the traditional medicine of Asian and European countries to treat central nervous system (migraine), respiratory (asthma, allergic rhinitis, bronchitis, spastic cough), cardiovascular (hypertension), gastrointestinal (ulcers) and genitourinary (dysmenorrhea) disorders.

AIM OF THE REVIEW

This study summarized and discussed the traditional uses, phytochemical, pharmacological and toxicological aspects of Petasites genus.

MATERIALS AND METHODS

A systematic search of Petasites in online databases (Scopus, PubMed, ScienceDirect, Google Scholar) was performed, with the aim to find the phytochemical, toxicological and bioactivity studies. The Global Biodiversity Information Facility, Plants of the World Online, World Flora Online and The Plant List databases were used to describe the taxonomy and geographical distribution.

RESULTS

The detailed phytochemistry of the potentially active compounds of Petasites genus (e.g. sesquiterpenes, pyrrolizidine alkaloids, polyphenols and essential oils components) was presented. The bioactivity studies (cell-free, cell-based, animal, and clinical) including the traditional uses of Petasites (e.g. anti-spasmolytic, hypotensive, anti-asthmatic activities) were addressed and followed by discussion of the main pharmacokinetical and toxicological issues related to the administration of butterbur-based formulations.

CONCLUSIONS

This review provides a complete overview of the Petasites geographical distribution, traditional use, phytochemistry, bioactivity, and toxicity. More than 200 different sesquiterpenes (eremophilanes, furanoeremophilanes, bakkenolides), 50 phenolic compounds (phenolic acids, flavonoids, lignans) and volatile compounds (monoterpenes, sesquiterpenes) have been reported within the genus. Considering the phytochemical complexity and the polypharmacological potential, there is a growing research interest to extend the current therapeutical applications of Petasites preparations (anti-migraine, anti-allergic) to other human ailments, such as central nervous system, cardiovascular, malignant or microbial diseases. This research pathway is extremely important, especially in the recent context of the pandemic situation, when there is an imperious need for novel drug candidates.

Petasites for Migraine Prevention: New Data on Mode of Action, Pharmacology and Safety. A Narrative Review

Petasins are the pharmacologically active ingredients of butterbur and of therapeutic benefit in the treatment of migraine and tension headaches. Here, we summarize the pharmacology, safety and clinical efficacy of butterbur in the prevention of migraine attacks and present new data on its mode of action. We review published literature and study reports on the safety and clinical efficacy of the butterbur root extract Petadolex® and report new findings on petasins in dampening nociception by desensitizing calcium-conducting TRP ion channels of primary sensory neurons. Importantly, butterbur diminishes the production of inflammatory mediators by inhibiting activities of cyclooxygenases, lipoxygenases and phospholipase A2 and desensitizes nociception by acting on TRPA1 and TRPPV1 ion channels. It inhibits the release of calcitonin-gene related peptide (CGRP) of meningeal afferents during migraine attacks. We also evaluated the safety of a butterbur root extract in repeated dose studies for up to 6 months. A no-observable-adverse-effect-level at 15-fold of the maximal clinical dose (3 mg/kg/day MCD) was established for rats. At supratherapeutic doses, i.e., 45–90-fold MCD, we observed bile duct hyperplasia, and mechanistic studies revealed regulations of solute carriers to likely account for bile duct proliferations. Additionally, liver function tests were performed in cultures of primary human hepatocytes and did not evidence hepatotoxicity at therapeutic butterbur level and with migraine co-medications. Lastly, in randomized, double-blinded and placebo-controlled trials with Petadolex® migraine attack frequency was reduced significantly at 150 mg/day, and no relevant abnormal liver function was reported. Together, butterbur is effective in the prevention of migraine attacks by blocking CGRP signaling.

Butterbur (Petasites hybridus) Extract Ameliorates Hepatic Damage Induced by Ovalbumin in Mice

The liver is the most vital organ that could be influenced by inducers of hypersensitivity such as ovalbumin. The current study was carried out to explore the effects of butterbur (Petasites hybridus) extract on the ovalbumin-induced liver hypersensitivity in Swiss albino male mice. Animals were divided into 4 groups, 1^st group served as a control group, 2^nd group treated with daily oral administration of 75 mg/kg of butterbur extract, 3^rd group received single oral dose 100 mg/kg of ovalbumin to induce hypersensitivity, and 4^th group treated with oral administration of butterbur extract one-day post to the hypersensitivity induction. Ovalbumin induces a significant increase in the activity of liver enzymes and MDA and decreased the activity of CAT after the ovalbumin treatment. Histopathological investigations revealed marked pathological alterations in liver tissues in the form of hyaline degeneration and fibrosis. Additionally, heavy immune response indicated by immunostaining of MDA and TNF-α could be observed. In contrast, posttreatment with butterbur extract after hypersensitivity induction resulted in a significant decrease of liver enzymes and oxidative stress and reduced the inflammation and fibrosis of liver tissues. These results suggest that butterbur extract is considered as anti-inflammatory and antioxidant therapeutic herb for hypersensitivity treatment of liver.

A novel petasin-modified zinc oxide eugenol sealer

Objective

Zinc oxide eugenol (ZOE) is one of the most commonly used root canal sealer. However, it has few drawbacks such as cytotoxicity, solubility, and irritation to periapical tissues. The scope of this study was to investigate the setting time, solubility, cytotoxic effects, and anti-inflammatory action of ZOE sealer with the modification of its liquid component by the addition of petasin extract in the ratios 1:1, 5:1, and 10:1.

Materials and Methods

Setting time was evaluated using the Vicat's apparatus. For testing solubility, the American Dental Association's specification #8 was adopted with certain modifications. Protein denaturation assay and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide assay with L929 mouse fibroblast cell lines were used to evaluate the anti-inflammatory property and cytotoxicity, respectively.

Results

ZOE sealer with petasin extract in the ratio of 5:1 showed the least initial and the final setting times. There was no statistically significant difference in the amount of solubility for all the groups at the various time intervals. The cytotoxicity of the control group was significantly greater than all the experimental groups, whereas the anti-inflammatory effect of the former was statistically lower.

Conclusions

The combination of ZOE with petasin extract in the ratio of 5:1 showed lower setting time, cytotoxicity, and better anti-inflammatory property.

Pharmacokinetic Herb-Drug Interactions: Insight into Mechanisms and Consequences

Herbal medicines are currently in high demand, and their popularity is steadily increasing. Because of their perceived effectiveness, fewer side effects and relatively low cost, they are being used for the management of numerous medical conditions. However, they are capable of affecting the pharmacokinetics and pharmacodynamics of coadministered conventional drugs. These interactions are particularly of clinically relevance when metabolizing enzymes and xenobiotic transporters, which are responsible for the fate of many drugs, are induced or inhibited, sometimes resulting in unexpected outcomes. This article discusses the general use of herbal medicines in the management of several ailments, their concurrent use with conventional therapy, mechanisms underlying herb-drug interactions (HDIs) as well as the drawbacks of herbal remedy use. The authors also suggest means of surveillance and safety monitoring of herbal medicines. Contrary to popular belief that "herbal medicines are totally safe," we are of the view that they are capable of causing significant toxic effects and altered pharmaceutical outcomes when coadministered with conventional medicines. Due to the paucity of information as well as sometimes conflicting reports on HDIs, much more research in this field is needed. The authors further suggest the need to standardize and better regulate herbal medicines in order to ensure their safety and efficacy when used alone or in combination with conventional drugs.

Complementary and alternative therapies: use in pediatric pulmonary medicine

With increased awareness of complementary/alternative medicine (CAM) and concern of potential adverse effects or limited effectiveness of conventional medications, patients and parents are looking to CAM approaches as either an alternative or as adjunct therapy, especially for chronic diseases such as asthma or cystic fibrosis. It is important that practitioners have adequate information so that patients and parents receive balanced and accurate information, especially regarding safety and potential efficacy. This review provides an overview of some of the more frequently used CAM therapies for children with chronic pulmonary disorders and summarizes the basic principles of each modality, along with efficacy and safety data.

Phytoceuticals: the new 'physic garden' for asthma and chronic obstructive pulmonary disease

Phytoceuticals (non-nutritional but beneficial plant chemicals) merit investigation as pharmacotherapy for asthma and chronic obstructive pulmonary disease (COPD). Although asthma is mostly treated adequately, COPD is not. Thus, there is a need for new drugs with improved therapeutic benefit, especially in COPD. Recent interest in herbal remedies has redirected attention towards plants as sources of improved treatments for lung disease. Phytoceuticals from a variety of plants and plant products, including butterbur, English ivy, apples, chocolate, green tea and red wine, demonstrate broad-spectrum pharmacotherapeutic activities that could be exploited in the clinic. Well-designed clinical trials are required to determine whether these beneficial activities are reproduced in patients, with the prospect that phytoceuticals are the new physic garden for asthma and COPD.

Complementary/alternative medicines in allergic disease

Complementary/alternative medicines is a generic term that encompasses a variety of approaches, including homeopathy, acupuncture, phytotherapy and numerous holistic or behavioral techniques. Complementary/alternative medicines are widely used in a number of conditions, including asthma and rhinitis. The medical literature on complementary/alternative medicines is impressive, but there are few clinical studies conducted with an appropriate methodology, and their results are negative or conflicting. In general, the results are insufficient to provide recommendations for the use of complementary/alternative medicines in clinical practice. Regarding diagnostic techniques, none have demonstrated the capability of distinguishing between healthy and allergic subjects and none are able to identify sensitizations.

Herbal interventions for chronic asthma in adults and children

BACKGROUND

Herb and plant based preparations are a popular treatment for asthma, although there remain concerns as to their efficacy and safety. In Western societies, motivations for using such treatments may be both positive and negative, with their perceived safety and dissatisfaction with conventional medicine among them. In China such treatments are more commonly used and many compounds considered 'conventional' are derived from herbs or plants.

OBJECTIVES

To assess the efficacy and safety of herb and plant extracts in the management of chronic asthma.

SEARCH STRATEGY

The Cochrane Airways Group Trials Register, CENTRAL, MEDLINE, EMBASE and AMED were searched with pre-defined terms. Searches are current as of February 2007.

SELECTION CRITERIA

Randomised placebo controlled trials of any herb or plant extract were eligible. Study participants had to have a primary diagnosis of asthma. Studies in both adults and children were eligible for the review.

DATA COLLECTION AND ANALYSIS

Two reviewers assessed studies for suitability. Data were extracted and double-checked.

MAIN RESULTS

Twenty-seven studies (29 experimental groups) met the review entry criteria, randomising a total of 1925 participants. The studies identified assessed the effects of 21 different herbal preparations. Study quality varied considerably, and the sample sizes were often small. For primary outcomes (exacerbations, steroids use and lung function measurements): Two out of six studies reporting change in FEV1 were positive, with very few data available on the frequency of exacerbations. One study which did report these data was negative. Health-related quality of life was only measured in one trial.

AUTHORS' CONCLUSIONS

The evidence base for the effects of herbal treatments is hampered by the variety of treatments assessed, poor reporting quality of the studies and lack of available data. The data that are available from the studies provide only a small insight into the long-term efficacy and harm profiles of these treatments. The absence of common endpoint measurements limits the validity of our findings further. Positive findings in this review warrant additional well-designed trials in this area.

Herbal treatments of asthma: a systematic review

BACKGROUND

Asthma is a condition, often chronic, characterized by respiratory symptoms, variable airflow limitation and/or airway hyper-reactivity with symptoms causally related to family history, environmental influences, exposure to viruses and allergens as examples. The high economic burden associated with asthma is associated primarily with health care costs, missed work or school days. This systematic review was conducted to determine the study quality of articles investigating ayurvedic/collateral herbs, the effectiveness/efficacy and safety profile, as reported in the studies.

METHODS

Literature searches were conducted using PubMed, EMBASE, Mantis, Ovid, Annotated Bibliography of Indian Medicine, and Cochrane library to identify published trials on herbal medicines for asthma of which Ayruvedic herbals are a subset. Randomized Controlled Trials (RCTs) and Quasi-Experimental Designs (QEDs) were included in this systematic review. The classic Jadad Scale, Singh RCT Scale with additional domains than Jadad, Safety Scoring Scale for clinical trials and the Singh QED Scale based on expanded features of QEDs were used to assess study quality. Herbs included in Traditional Chinese Medicine were excluded from this review. Forty-two articles were retrieved and 37 studies were ultimately reviewed utilizing 3 independent evaluators/1 arbitrator.

RESULTS

Articles reviewed indicated benefit from most of the herbs used either as a primary or adjunctive treatment for Asthma. Study quality was mixed and therefore caution in interpretation of findings of usefulness of these herbals must be suggested. Limited safety information was mixed and generally was related to GI symptoms, though one herbal investigated reported more serious side effects.

CONCLUSIONS

Herbs may be useful in treatment of asthma. There is insufficient evidence to make recommendations for or against the use of these herbals. Established effectiveness must be balanced with study quality and safety profile for the herb.

Effects of intranasal corticosteroid on nasal adenosine monophosphate challenge in persistent allergic rhinitis

BACKGROUND

Response to a single dose nasal adenosine monophosphate challenge has been used as a surrogate inflammatory marker for allergic rhinitis. Attenuation of response following intranasal corticosteroid would further validate the challenge.

OBJECTIVE

To assess the effect of 4 weeks of 200 mcg once daily mometasone furoate nasal spray on a simplified (single 160 mg dose) nasal adenosine monophosphate challenge.

METHODS

Twenty participants with persistent allergic rhinitis completed a double blind placebo-controlled crossover study. Outcome measures were the peak nasal inspiratory flow and total nasal symptoms score responses to nasal adenosine monophosphate challenge, as well as domiciliary peak nasal inspiratory flow and patient symptom diary cards.

RESULTS

Mometasone significantly (P < 0.05) attenuated response time profiles vs. placebo for peak nasal inspiratory flow but not total nasal symptom scores. For the maximum percentage fall this amounted to a mean difference of 9.6% (95% confidence interval 1.3-17.9%). The coefficient of variation for repeatability was 48.7%. Improvements were seen in prechallenge and domiciliary measurements of peak nasal inspiratory flow (both P < 0.05) and total nasal symptom scores (both P < 0.01).

CONCLUSIONS

Mometasone attenuates the peak nasal inspiratory flow response to a single 160 mg nasal adenosine monophosphate challenge. Such challenges have been shown to be sensitive to the effects of antihistamines, antileukotrienes and now nasal steroids. This further supports their application as surrogate inflammatory markers for therapeutic trials in allergic rhinitis, potentially as 20 min challenges which can be conducted in a non-hospital setting.

ARIA update: I--Systematic review of complementary and alternative medicine for rhinitis and asthma

Complementary-alternative medicines are extensively used in the treatment of allergic rhinitis and asthma, but evidence-based recommendations are lacking. To provide evidence-based recommendations, the literature was searched by using MedLine and the Cochrane Library to March 2005 (Key words: Asthma [OR] Rhinitis, [AND] Complementary [OR] Alternative Medicine, [OR] Herbal, [OR] Acupuncture, [OR] Homeopathy, [OR] Alternative Treatment). Randomized trials, preferably double-blind and published in English, were selected. The articles were evaluated by a panel of experts. Quality of reporting was assessed by using the scale validated by Jadad. The methodology of clinical trials with complementary-alternative medicine was frequently inadequate. Meta-analyses provided no clear evidence for the efficacy of acupuncture in rhinitis and asthma. Some positive results were described with homeopathy in good-quality trials in rhinitis, but a number of negative studies were also found. Therefore it is not possible to provide evidence-based recommendations for homeopathy in the treatment of allergic rhinitis, and further trials are needed. A limited number of studies of herbal remedies showed some efficacy in rhinitis and asthma, but the studies were too few to make recommendations. There are also unresolved safety concerns. Therapeutic efficacy of complementary-alternative treatments for rhinitis and asthma is not supported by currently available evidence.

Does acupuncture or Chinese herbal medicine have a role in the treatment of allergic rhinitis?

PURPOSE OF REVIEW

Complementary medicines, including acupuncture and Chinese herbal medicine, are being used increasingly for the management of allergies such as allergic rhinitis. Until relatively recently, however, evidence for the efficacy and safety of these therapies in allergic conditions has been lacking.

RECENT FINDINGS

A limited number of well conducted studies, all with small sample sizes, have demonstrated the promising therapeutic potential of acupuncture and Chinese herbal medicine for allergic rhinitis. The possible additional benefit of combining the two therapies, however, is yet to be confirmed. There are concerns about the appropriateness of the sham/placebo controls that have been used in acupuncture studies and also about the safety evaluation of individual herbs and herbal formulations. In addition to well established symptom scores and specific quality of life questionnaires, the concurrent use of conventional anti-allergy medications has been utilized as an outcome measure in a number of trials that have evaluated the effectiveness of acupuncture and Chinese herbal medicine for allergic rhinitis.

SUMMARY

Tentatively, it appears that acupuncture and Chinese herbal medicine can be effective treatments for allergic rhinitis. Confirmatory evidence, however, is needed from large and, ideally, multi-centre trials.

Treating intermittent allergic rhinitis: a prospective, randomized, placebo and antihistamine-controlled study of Butterbur extract Ze 339

BACKGROUND

Intermittent allergic rhinitis (IAR) causes patients distress and impairs their work performance and quality of life. A variety of medicines are used by sufferers whose anguish frequently leads to trying new treatments, increasingly from herbal sources.

METHODS

Prospective, randomized, double-blind, parallel group comparison study of Butterbur extract (Ze 339; 8 mg total petasine; one tablet thrice-daily), fexofenadine (Telfast 180, one tablet once-daily) and placebo in 330 patients. Protocol and analysis were according to the latest guidelines on new treatments for allergic rhinitis. The primary efficacy variable was a change in symptoms from baseline to endpoint during daytime. The secondary efficacy variables were: (a) as per primary variable (evening/night); (b) Physician's global assessment; (c) Responder rates. Safety was closely monitored.

FINDINGS

Both active treatments were individually significantly superior to placebo (p<0.001) in improving symptoms of IAR, while there were no differences between the two active treatments (p=0.37). Superiority to placebo was similarly shown during the evening/night (p<0.001), by physicians' own assessment and by responder rates. Both treatments were well tolerated.

INTERPRETATION

Butterbur Ze 339 and Fexofenadine are comparably efficacious relative to placebo. Despite being a herbal drug, Butterbur Ze 339 has now been subject to a series of well controlled trials and should be considered as an alternative treatment for IAR.

Effects of butterbur treatment in intermittent allergic rhinitis: a placebo-controlled evaluation

BACKGROUND

Butterbur (Petasites hybridus) contains the active ingredient petasin, which exhibits antileukotriene and antihistamine activity. Previous studies of intermittent allergic rhinitis (IAR) have demonstrated a comparable response to butterbur compared with a histamine H1-receptor antagonist on the 36-Item Short-Form Health Survey quality-of-life score. However, there has been no placebo-controlled study of the effects of butterbur use on objective and subjective outcomes in IAR.

OBJECTIVE

To evaluate the effects of treatment with butterbur vs placebo on objective and subjective outcomes in IAR.

METHODS

A double-blind, placebo-controlled, crossover study was carried out during the grass pollen season in Tayside, Scotland. Thirty-five patients (14 men and 21 women) with IAR received butterbur, 50 mg twice daily, or placebo for 2 weeks. Domiciliary measurements were taken in the morning and evening for peak nasal inspiratory flow (PNIF) (the primary outcome variable), nasal and eye symptoms, and rhinoconjunctivitis-specific quality-of-life score.

RESULTS

Butterbur treatment had no significant effect on PNIF, total nasal symptom score, eye symptom score, or quality of life compared with placebo use. Mean (SEM) morning and evening PNIF values were 107 (6) and 114 (6) L/min, respectively, for butterbur vs 105 (6) and 117 (6) L/min for placebo. Mean (SEM) morning and evening total nasal symptom scores (maximum total score, 12) were 3.4 (0.4) and 3.5 (0.4), respectively, for butterbur vs 3.7 (0.3) and 3.8 (0.4) for placebo.

CONCLUSIONS

There was no significant clinical efficacy of butterbur use vs placebo use on objective and subjective outcomes in IAR. Further studies are now indicated to investigate the use of butterbur in persistent allergic rhinitis.