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Cautions Regarding Butterbur for Allergic Rhinitis
- Andrew M. Davis, MD (21 January 2002)
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Toxicity of pyrrolizidine alkaloids
- Firenzuoli Fabio, Gori L (22 January 2002)
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The trial does not show that there is no difference between butturbur and cetirizine
- Craig A McArthur, Neil Arnott (24 January 2002)
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Lack of evidence of difference is not evidence of lack of difference
- Adam Jacobs (24 January 2002)
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A knife through butterbur
- Haytham Kubba, Michael Oko (6 February 2002)
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Butturbur and cetirizine for treating seasonal allergic rhinitis
- Werner J. Pichler, Benno Schnyder, Juerg Hüsler (20 March 2002)
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Butterbur: 17th century remedy and 21st century science
- Daniel K C Lee (11 April 2004)
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Allergies : The Case For Further CAM Research On Butterbur
- Joseph . C . Obi (12 April 2004)
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Re: Allergies : The Case For Further CAM Research On Butterbur (Professor Joseph Obi)
- Clarrisa Fonduquet (19 April 2004)
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Andrew M. Davis, MD, Asst Professor of Clinical Internal Medicine University of Chicago 5841 S. Maryland MC 3051 Chicago, IL 60637
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Two cautions are in order before practitioners widely prescribe butterbur, particularly in countries that have lax herbal regulations, such as the United States . The first is that uncertified butterbur preparations may contain unsaturated pyrrolizidine alkaloids with the potential for serious hepatotoxic and teratogenic effects(1). Secondly cross-allergenicity may be seen between butterbur and other herbs in the Asteraceae/Compositae family, such as ragweed, which may be significant contributors to seasonal allergic rhinitis. Does butterbur have the helpful results seen in this trial in patients sensitive to ragweed? 1) Mauz C, Candrian U, Luthy J, et al. Method for the reduction of pyrrolizidine alkaloids from medicinal plant extracts [Article in German; English abstract]. Pharm Acta Helv. 1985;60:256–259. |
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Firenzuoli Fabio, Department of Phytotherapy Via Paladini 1 , S. Giuseppe Hospital, 50053 Empoli (Italy), Gori L
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Many medicinal plants are used as treatment in traditional medicine, often without any evidence of efficacy and sufficient safety. Butterbur (Petasites hybridus L. or P. officinalis L.), Coltsfoot (Tussilago farfara L.) , Common comfrey (Symphytum officinale L.), Borage (Borago officinalis L.) , Crotalaria (Crotalaria retusa L.) and Common groundsel (Senecio vulgaris L.) are only few samples of medicinal plants for which there is a very old tradition of use, few clinical data on their pharmacological efficacy, while enough data to state they toxic and cancerogenic , because all these plants contain pyrrizolidine alkaloids(PA). In reference to the paper of Dr. A. Schapowal, we think the Author did not deserve any attention to the main toxicological problematics of Petasites hybridus. This plant in fact is known to contain PA: in rhizomes they range from 5 to 90 ppm, whereas leaves contain between 0.02 to 1.50 ppm (1). PA are usually concentrated in the metabolically active parts of the complex rhizome which are the thickenings just below the leaves. They are also present in flower stalks but are almost absent in leaf buds, the petioles and the leaf blades (2). PA and PA-N-oxides induce tumors via a genotoxic mechanism, and tumorigenicity is mediated by a set of eight dehydroretronecine-derived DNA adducts. This mechanism may be general to other carcinogenic PA and may also be responsible for the other genotoxicities of PA, including mutagenicity and teratogenicity (3). Besides the well known hepatotoxicty of PA, they have been associated with potentially fatal hepatic veno-occlusive disease (Budd-Chiari Syndrome) and fibrotic lung disease (4). Papers dealing with herbal extract should report complete extractive techniques, content of main constituents, presence or absence of toxic substances, probable or demonstrated toxic effects, drugs interferences and geographical area of production. About Petasites hybridus the aim of future research should be the evidence of clinical activity of preparations without PA content, especially for chronic treatment and administration in gestational age and childhood. We think should be improved vigilance of medical authorities on the use, often as self-therapy, of over-the-counter herbal derivatives from which toxic constituents have not been removed (5). Bibliography 1. Wildi E, Langer T, Schaffner W, et al.: Quantitative analysis of petasin and pyrrolizidine alkaloids in leaves and rhizomes of in situ grown Petasites hybridus plants. Planta medica 1998;64:264-267. 2. Chizzola R, Ozelsberger B, Langer T.: Variability in chemical constituents in Petasites hybridus from Austria. Bioch Syst Ecology 2000; 28: 421-432. 3. Fu PP, Chou MW, Xia Q, et al.: Genotoxic pyrrolizidine alkaloid N- oxides. Mechanism leading to DNA adduct formation and tumorigenicity. J Environ Sci Health 2001; 19/2: 353-385. 4. Pearson W.: Pyrrolizidine alkaloids in higher plants: Hepatic veno- occlusive disease associated with chronic consumption. J Nutraceuticals Funct Med Foods 2000; 3/1: 87-96. 5. Firenzuoli F, Gori L.: Herbal medicine. Minerva Med 2001; 92 (Suppl. 1 al N.3): 1-14. |
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Craig A McArthur, Partner in General Practice Tweeddale Medical Practice, High Street, Fort William, PH33 6EU, Neil Arnott
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We would like to raise two points regarding the paper by Schapowal et al. We feel there may be a possibility of bias and we would question the statistical interpretation of the data. This is an unusual clinical trial in that it seems to be trying to prove no difference between the treatment arms. Most trials are trying to show that one treatment is better than the other. It is this unusual feature which gives us concern regarding the methodology and the analysis. In the usual situation, where a trial is investigating a possible difference between treatments, double blinding is used to prevent bias by patients or researchers. Without knowing which treatment they are on, they cannot consistently overestimate one or other of the treatment effects. However, if the hypothesis is that there is no difference between treatments, it is possible to bias the result towards supporting the hypothesis. This happens if one tends to score all patients similarly. This bias could easily result unconsciously on behalf of patients and researchers. Given that the trial on Butterbur (a petasite) is conducted by the Petasites study Group there may well be a strong desire for the researchers to prove their hypothesis and this makes them vulnerable to unconsciously biasing the results in this way. We would also like to question the interpretation of the data. The authors use a “Mann-Whitney rank sum test (one sided)”. They state that significant values mean Butterbur is not inferior. The P values for this test are mostly 0.001. This seems to imply that Butterbur has been shown to be not inferior to cetirizine with only a 0.1% chance of this result being wrong. Our understanding is that in general there are two errors that a trial can make. Type one error is for the trial to show a difference between treatments when, in reality there is no true difference. The risk of this error occurring is quantified by the P value. The P value is therefore important when assessing the usual type of trial which is claiming to show a difference. Type two error on the other hand is for the trial to show no difference between treatments when, in reality there is a true difference. The risk of this error occurring is quantified by the power calculation. Therefore it is the power of the study which is crucial in this trial which claims to have found no difference between treatments. The authors quote an 80% power for the study. This means that there is a 20% chance of a type two error occurring. That is a 20% chance that there is in reality a difference between Butterbur and cetirizine and that the trial results are wrong, (not a 0.1% chance as implied in the paper.) To summarise, the trial fails to show evidence of a difference between the treatments but it also fails to show evidence of no difference. There is subtle but very important distinction between these two statements. In effect the trial does not really give any support one way or another to justify the use of Butturbur. |
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Adam Jacobs, Director Dianthus Medical Limited, SW19 3TZ
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Schapowal concludes that butterbur and cetirizine are of equal efficacy in treating allergic rhinitis [1], but it is difficult to see how this conclusion can be justified from the results presented. The lack of a significant difference between the two treatments is not proof that the treatments are equivalent: it could be simply that the study was underpowered. It is not easy to follow the statistical methods section of the paper. We are told that the sample size calculation was based on an assumed effect size of 0.5. However, we are not told anywhere in the paper what the observed effect size was. Indeed, using effect size (usually defined as the difference between the treatments in the primary outcome variable divided by the standard deviation of the variable) is an inappropriate way of calculating the sample size here, as the analysis was done using non-parametric statistics. Calculations on the basis of standard deviations assume that data are normally distributed, and non- parametric statistics are used when there is good reason to believe that there is an important deviation from normality. I am also puzzled by the test of non-inferiority. It seems strange that significant P values mean that butterbur is not inferior. Surely it would be more conventional to have a null hypothesis that butterbur is not inferior (and that significant P values would therefore show that butterbur is inferior). What exactly was the null hypothesis here? Moreover, Schapowal seems to make a distinction between the statistical tests used for the comparison between the medians (the Mann-Whitney test) and for the non-inferiority test (the ‘Mann-Whitney rank sum test’). The Mann-Whitney test is statistically equivalent to the Wilcoxon rank sum test, and I assume that the ‘Mann-Whitney rank sum test’ is one or other of those. This spurious distinction only adds to the confusion. If a study is to show the equivalence of two drugs, it should ideally show that the 95% confidence interval for the difference between the drugs is contained within limits considered to be of no clinical significance, or failing that, should at the very least combine non-significant P values for the difference between treatments with a rigorous demonstration that the study was adequately powered to detect a difference. Schapowal does neither. 1. Schapowal A. Randomised controlled trial of butterbur and cetirizine for treating seasonal allergic rhinitis. BMJ 2002;324:144-146 |
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Haytham Kubba, Specialist Registrar in Otolaryngology Gartnavel General Hospital, Glasgow, Scotland, Michael Oko
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We must take issue with the author of the trial of butterbur versus cetirizine for seasonal allergic rhinitis (1) on three main issues. That the trial has failed to show that one treatment is better than the other does not mean that it has shown them to be equally good. A power of 80% means a 20% chance of failing to show a difference when one is actually present. A negative result from such a small sample size should be treated with great caution. The effect size of 0.5 in the power analysis is given without any explanation or justification. A negative result, however, was always likely, given the inappropriate choice of outcome measures. The physician-rated improvement scores do not reflect the patients’ own perceptions of whether they are better or not. The only patient-centred outcome used is overall quality of life, as rated on SF36. This is a blunt instrument, and very large numbers of subjects would be required to show a difference between any two groups, because reported quality of life varies so much between individuals, even those with the same severity of disease. Why is there no comparison of symptoms? 10cm visual analogues for sneeze, itching, blockage, rhinorrhoea and hyposmia would be reasonable, as would some sort of objective measure (peak nasal inspiratory flow rate, for example). A disease-specific quality of life measure such as the Rhinoconjunctivitis Quality of Life Questionnaire (2) would also have been a good addition. As it is, we have no evidence that butterbur improves the symptoms of rhinitis at all. The other major concern is that the paper fails to mention the hepatotoxicity, teratogenicity and carcinogenicity of the actve alkaloid ingredients of butterbur . This will do nothing to correct the widely- held fallacy that herbal remedies (unlicensed, poorly tested and poorly standardised) are somehow safer than pharmaceuticals, just because they are perceived to be “natural”. Butterbur has potential dangers, and this industry-sponsored trial shows no evidence that it is effective at all, let alone as effective as cetirizine. It cannot be recommended for use on the basis of this evidence. References: 1. Schapowal A. Randomised controlled trial of butterbur and cetirizine for treating seasonal allergic rhinitis BMJ 2002; 324: 144-146 2. Juniper EF. Rhinitis management: the patients’ perspective Clin Exp All 1998; 28(supp 6): 34-38 |
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Werner J. Pichler, Head, Div. of Allergology, Inselspital, Univ. of Bern Inselspital, CH 3010 Bern, Switzerland, Benno Schnyder, Juerg Hüsler
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Butturbur and cetirizine for treating seasonal allergic rhinitis: an example of alleged “evidence based medicine” The paper by Schapowal et al. (1) postulates that the effects of butturbur and ceterizine were comparable in patients with hay fever. The wording of this conclusion is misleading, because an equivalence of specific therapeutic effects has not been documented by appropriate biometrical respectively statistical analysis: - The main outcome variable was the health survey questionnaire SF36 Score. This score is validated for an overall assessment of physical and mental integrity but has no specificity for seasonal allergic rhinitis (2). - Efficacy has to be assessed by the difference between values after therapy minus baseline as indicated in the paper under statistics. The results are given as absolute values after two weeks‘ treatment but not as values for the difference. - The information about statistical methods and results is sparse and incomplete. E.g. the analysis included each of out 8 items of the SF-36. There is no clear information about the correction for multiple testing. - The study intends to show non-inferiority, which asks for appropriate design and statistical analysis. E.g. an adequate primary endpoint has to be selected and justified. The statistical analysis has to be performed in the PP and not in the ITT-population. Confidence intervals would be more appropriate for the presentation of the results, but are not given. The wording of a correct conclusion should be: „After a two week treatment with butterbur or cetirizine similar effects regarding physical and mental integrity in patients with hay fever were observed. Butterbur may produce fewer sedating effects than cetirizine. Both observations are not demonstrated by appropriate statistical methods“. Since in addition to statistical errors of this paper (3,4,5), also concerns about the toxicity of butterbur were raised in some letters (6,7), a clarifying statement by the BMJ is actually needed and expected. 1. Schapowal A. Randomised controlled trial of butterbur and cetirizine for treating seasonal allergic rhinitis BMJ 2002;324:144 2. Ware JJ, Sherbourne CD. The MOS 36-item short-form health survey (SF- 36). I. Conceptual framework and item selection. Medical Care 1992; 30:473 -83. 3. Kubba H, Oko M. A knife through butterbur bmj.com, 5 Feb 2002 4. Jacobs A. Lack of evidence of difference is not evidence of lack of difference bmj.com, 24 Jan 2002 5. McArthur CA, Arnott N. The trial does not show that there is no difference between butturbur and cetirizine bmj.com, 24 Jan 2002 6. Davis A.M. Cautions regarding butterbur for allergic rhinitis bmj.com, 21 Jan 2002 7. Firenzuoli F., Gori F. Toxicity of pyrrolizidine alkaloids. bmj.com 22 Jan 2002 Benno Schnyder, Juerg Hüsler and Werner J. Pichler, Division of
Allergology, Inselspital,
Univ. of Bern, Switzerland;
No competing interests of the three authors |
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Daniel K C Lee, Respiratory Physician Department of Respiratory Medicine, Ipswich Hospital, Heath Road, Ipswich IP4 5PD, Suffolk, England
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The study by Schapowal1 showed that a herbal remedy, butterbur or Petasites hybridus, was as effective as second generation histamine H1-receptor antagonist, cetirizine, in improving nasal symptoms in patients with seasonal allergic rhinitis, albeit in the backdrop of major criticisms,2;3 including the use of one-sided statistical analysis in a non-placebo-controlled study based on subjective outcome measure. In a recent randomised, double-blind, placebo-controlled study, in patients with seasonal allergic rhinitis, butterbur was shown to be effective in attenuating the response to nasal provocation testing with adenosine monophosphate,4 which acts through A2-purinoceptors on primed mast cells leading to degranulation and release of mediators such as histamine, cysteinyl leukotrienes, and prostaglandins.5 Butterbur has also been found to be equally effective compared to modern or third generation histamine H1-receptor antagonist, fexofenadine, in conferring protection against nasal adenosine monophosphate challenge as well as in improving nasal symptoms in patients with perennial allergic rhinitis.6 Furthermore, with the recognition of both the upper and lower airway as being part of a unified airway,7 butterbur has been shown to improve airway hyper-reactivity following bronchial adenosine monophosphate challenge compared to placebo in asthmatic patients maintained on inhaled corticosteroids.8 However, butterbur may not be effective in allergic skin disease as butterbur did not produce any significant effects on the histamine and allergen cutaneous response compared to placebo in atopic patients.9 Although the exact mechanism of action of butterbur has yet to be fully elucidated, petasin, the active ingredient of butterbur, has been found to inhibit the biosynthesis of histamine and cysteinyl leukotrienes in vitro, in addition to blocking the release of serum eosinophil cationic protein.10-13 In vivo, butterbur has been shown to reduce levels of histamine and cysteinyl leukotrienes from nasal lavage.14 One must not forget that butterbur in its unpurified form contain toxic pyrrolizidine alkaloids which have been linked to hepatotoxicity and carcinogenicity.15 In addition, butterbur has been shown to inhibit testosterone production using an animal model.16 Therefore, even though there is potentially a therapeutic role for butterbur in allergic rhinitis and asthma, further rigorous studies relating specifically to issues surrounding the potential long-term side-effects of butterbur would need to be conducted before butterbur can be recommended for use in the treatment of allergic airway disease. References 1. Schapowal A. Randomised controlled trial of butterbur and cetirizine for treating seasonal allergic rhinitis. BMJ 2002;324:144. 2. Shuster S. Treating seasonal allergic rhinitis. Well designed experiments should have been used. BMJ 2002;324:1277. 3. McArthur CA,.Arnott N. Treating seasonal allergic rhinitis. Trial does not show that there is no difference between butterbur and cetirizine. BMJ 2002;324:1277. 4. Lee DK, Carstairs IJ, Haggart K, Jackson CM, Currie GP, Lipworth BJ. Butterbur, a herbal remedy, attenuates adenosine monophosphate induced nasal responsiveness in seasonal allergic rhinitis. Clin Exp Allergy 2003;33:882-6. 5. Lee DK, Gray RD, Lipworth BJ. Adenosine monophosphate bronchial provocation and the actions of asthma therapy. Clin Exp Allergy 2003;33:287-94. 6. Lee DK, Gray RD, Robb FM, Fujihara S, Lipworth BJ. A placebo-controlled evaluation of butterbur and fexofenadine on objective and subjective outcomes in perennial allergic rhinitis. Clin Exp Allergy 2004;34:646-9. 7. Bousquet J, van Cauwenberge P, Khaltaev N. Allergic rhinitis and its impact on asthma. J Allergy Clin Immunol 2001;108:S147-S334. 8. Lee DK, Haggart K, Robb FM, Lipworth BJ. Butterbur, a herbal remedy, confers complementary anti-inflammatory activity in asthmatic patients receiving inhaled corticosteroids. Clin Exp Allergy 2004;34:110-4. 9. Jackson CM, Lee DK, Lipworth BJ. The effects of butterbur on the histamine and allergen cutaneous response. Ann Allergy Asthma Immunol 2004;92:250-4. 10. Thomet OA, Wiesmann UN, Blaser K, Simon HU. Differential inhibition of inflammatory effector functions by petasin, isopetasin and neopetasin in human eosinophils. Clin Exp Allergy 2001;31:1310-20. 11. Brune K, Bickel D, Peskar BA. Gastro-protective effects by extracts of Petasites hybridus: the role of inhibition of peptido-leukotriene synthesis. Planta Med 1993;59:494-6. 12. Bickel D, Roder T, Bestmann HJ, Brune K. Identification and characterization of inhibitors of peptido-leukotriene-synthesis from Petasites hybridus. Planta Med 1994;60:318-22. 13. Thomet OA, Wiesmann UN, Schapowal A, Bizer C, Simon H. Role of petasin in the potential anti-inflammatory activity of a plant extract of petasites hybridus. Biochem Pharmacol 2001;61:1041-7. 14. Thomet OA, Schapowal A, Heinisch IV, Wiesmann UN, Simon HU. Anti-inflammatory activity of an extract of Petasites hybridus in allergic rhinitis. J Immunopharmacol 2002;2:997-1006. 15. Barnes J. Safety concerns over butterbur. Pharm J 2002;268:123-30. 16. Lin H, Chien CH, Lin YL, Chen CF, Wang PS. Inhibition of testosterone secretion by S-petasin in rat testicular interstitial cells. Chin J Physiol 2000;43:99-103. Competing interests: None declared |
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Joseph . C . Obi, Professor Of Complementary and Alternative Medicine (CAM) Research ; School Of Natural Medicine , Larnarca , Cyprus , European Union .
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Those of us 'Wellness Consultants' who have been successfully using Butterbur for many years now, are not surprised at it's recent success in a Randomized Clinical Trial against Cetirizine, for the treatment of Seasonal Allergic Rhinitis (SAR) ; as warmly indexed under Andreas Schapowal et al : BMJ, 2002 Jan 19;324(7330):144-6 *** Infact , many of us consistently feel that Butterbur may also be exceedingly efficacious in Perennial Allergic Rhinitis (PAR)...and a whole host of other related conditions too. The highly laudable fact that Butterbur does not have any sedating properties , therapeutically adds more icing to the cake. Without wanting to be seen as being 'immensely over-excited' about these momentously inspiring results, permit me to humbly provide a few widely known excerpts on Butterbur; as placed in the public domain by the Alternative Medicine Review , way back in 2001. Admittedly, the Butterbur sample sizes are not as huge as those portrayed in many other trials, but at least we are warmly provided with a very welcome 'start' in the exponentially expanding field of Complementary and Alternative Medicine (CAM) Research. Listen...and Learn. Petasites Hybridus (Butterbur). Source : Alternative Medicine Review , 2001. Introduction : Petasides hybridus (butterbur) is a perennial shrub, found throughout Europe as well as parts of Asia and North America, that has been used medicinally for centuries. During the Middle Ages butterbur was used to treat plague and fever; in the 17th century its use was noted in treating cough, asthma, and skin wounds.[l,2] The plant can grow to a height of three feet and is usually found in wet, marshy ground, in damp forests, and adjacent to rivers or streams. Its downy leaves can attain a diameter of three feet, making it the largest of all indigenous floras, and their unique characteristics are responsible for the plant's botanical and common names. The genus name, Petasites, is derived from the Greek word petasos, which is the felt hat worn by shepherds.[2] The common name of butterbur is attributed to the large leaves being used to wrap butter during warm weather.[3] Other common names include pestwurz (German), blatterdock, bog rhubarb, and butter-dock.[2] Currently, the primary therapeutic uses for butterbur are for prophylactic treatment of migraines, and as an antispasmodic agent for chronic cough or asthma. It has also been used successfully in preventing gastric ulcers, and in treating patients with irritable bladder and urinary tract spasms.[2,4] Active Constituents: Extracts of Petasites hybridus are prepared from the rhizomes, roots, and leaves. The main active constituents are two sesquiterpenes, petasin and isopetasin. Petasin is responsible for the antispasmodic properties of the plant by reducing spasms in smooth muscle and vascular walls, in addition to providing an anti-inflammatory effect by inhibiting leukotriene synthesis. Prostaglandins are important mediators in the inflammatory process and isopetasin's positive impact on prostaglandin metabolism contributes to the effectiveness of Petasites extracts. Extracts of the plant also contain volatile oils, flavonoids, tannins, and pyrrolizidine alkaloids. As these alkaloids are believed to be toxic to the liver and carcinogenic in animals, extracts are available in which the pyrrolizidine alkaloids have been removed.[2] Mechanisms of Action:The active constituents of Petasites have an antispasmodic effect on vascular walls and appear to have an affinity for cerebral blood vessels. Petasites' ability to reduce smooth muscle spasm suggests it may be a useful therapeutic tool in treating urinary disorders, menstrual cramps, migraine headaches, kidney stone disorders, obstruction of bile flow, as well as other liver or gastrointestinal disorders associated with smooth muscle spasm.[1] The anti-inflammatory properties of butterbur extracts are attributed to inhibition of lipoxygenase activity and down-regulation of leukotriene synthesis, and are primarily due to the petasin content.[5]. Clinical Indications: *Migraine Headache :Two clinical studies using 50 mg of a standardized Petasites extract twice daily for 12 weeks demonstrated its effectiveness as a prophylactic treatment for migraines. Both studies were double-blind, placebo controlled, and involved a total of 128 patients. The results of the two studies showed a significant reduction (as much as 60%) in frequency of migraine attacks compared to placebo. Other improvements in the Petasites group included a reduction in the number of days with migraines per month, a decrease in migraine-associated symptoms, and diminished duration and intensity of pain. No adverse reactions were reported in either study. Butterbur extract's high degree of efficacy and excellent tolerability accentuates its value in the prophylactic treatment of migraines.[6,7] *Asthma/Bronchitis :Various parts of the butterbur plant have been used for centuries to treat bronchial asthma and whooping cough, and in folk medicine the leaves of the plant were used as a mucus-reducing cough remedy. Butterbur's ostensible effectiveness in treating upper respiratory disorders such as asthma and bronchitis is attributed to the antispasmodic properties of the petasin constituent. The plant's anti-inflammatory action would also help calm the reactive airways seen in both asthma and bronchitis.[2] A Polish clinical study conducted in 1998 examined the influence of Petasites on lung ventilation and bronchial reactivity in patients suffering from asthma or chronic obstructive bronchitis. The study included three test groups and two control groups. Test Group A exhibited an improvement in forced expiratory volume (FEV1) three hours after an oral dose of 600 mg Petasites extract. Group B experienced a significant decrease in bronchial reactivity two hours after receiving an oral dose of 600 mg Petasites extract. Group C patients were treated for 14 days and received 600 mg of the extract three times daily. Some patients (n=10) were also given corticosteroids due to disease severity. All three groups exhibited a decrease in bronchial reactivity, but the patients in Group C who received no corticosteroids had the most pronounced results.[8] These results indicate Petasites might be helpful in improving lung ventilation in patients with asthma or chronic obstructive bronchitis. *Gastrointestinal Disorders : Butterbur's use as an antispasmodic for gastrointestinal conditions dates back to the Middle Ages. The leaves and rhizomes were used to treat spasms of the digestive tract associated with colic, plague, and bile flow obstruction.[9,10]. A German study conducted in 1993 found ethanolic extracts of Petasites hybridus blocked ethanol-induced gastric damage and reduced ulcerations of the small intestine caused by indomethacin, an anti- inflammatory drug used to treat arthritic conditions. The results of this study were attributed to inhibition of lipoxygenase activity and leukotriene biosynthesis.[11]. Safety : Until recently, side effects from Petasites extracts had not been reported. In September 2000, a study conducted in Taiwan noted the petasin constituent, responsible for many of butterbur's pharmacological properties, inhibited the production of testosterone in rat testicular cells, but did not speculate whether this effect would be applicable in humans.[12]. The plant's pyrrolizidine alkaloids are thought to cause liver damage and to be carcinogenic in animals; however, extracts are commercially available in which the pyrrolizidine alkaloids have been removed. There are no known interactions with either pharmaceutical or over- the-counter anti-inflammatory agents; however, use of Petasites extracts during pregnancy and lactation is contraindicated.[1]. Dosage : Typically, Petasites extracts are standardized to contain a minimum of 7.5 mg of petasin and isopetasin. The adult dosage ranges from 50-100 mg twice daily with meals. When used to treat migraines, administration is prophylactic and supplementation should be carried out daily for four to six months and then tapered until migraine incidence begins to increase. Dosage regimens for asthma and gastrointestinal disorders are as yet undefined, dictating the need for further research. References [1.] Eaton J. Butterbur, herbal help for migraine. Nat Pharm 1998;2:1,23-24. [2.] Mauskop, A. Petasites hybridus: ancient medicinal plant is effective prophylactic treatment for migraine. Townsend Lett 2000;202:104- 106. [3.] Grieve M. Butterbur. In: Leyel CF, ed. A Modern Herbal, electronic version. New York, NY: Dover Publications, Inc. 1971. [4.] Reglin F. A clinical review: Petadolex [R] (Standardized Butterbur Extract), Praxis-Telegram, Nr. 1/98:13-14. [5.] Bickel D, Roder T, Bestmann HJ, Brune K. Identification and characterization of inhibitors of peptido-leukotriene synthesis from Petasites hybridus. Planta Med 1994;60:318-322. [6.] Mauskop A, Grossmann WM, Schmidramsl H. Petasites hybridus (butterbur root) extract is effective in the prophylaxis of migraines. Results of a randomized, double-blind trial. J Head Face Pain 2000;40:4. [7.] Grossmann WM, Schmidramsl H. An extract of Petasites hybridus is effective in the prophylaxis of migraine. Int J Clin Pharmacol Ther 2000;38:430-435. [8.] Ziolo G, Samochowiec L. Study on clinical properties and mechanism of action of Petasites in bronchial asthma and chronic obstructive bronchitis. Pharmaceutica Acta Helvetica 1998;72:359-380. [9.] Lindauerova T. Palynomorphological investigation of the species Petasites hybridus and Petasites albus. Farmaceuticky Obzor 1981:50:569- 574. [10.] Blumenthal M, ed. The Complete German Commission E Monographs. Austin, TX: American Botanical Council; 1998;183:365. [11.] Brune K, Bickel D, Peskar BA. Gastro-protective effects by extracts of Petasites hybridus: the role of inhibition of peptido- leukotriene synthesis. Planta Med 1993;59:494-496. [12.] Lin H, Chien CH, Lin YL, et al. Inhibition of testosterone secretion by S-petasin in rat testicular interstitial cells. Chin J Physiol 2000:43:99-103. ***Supporting BMJ Weblink : http://bmj.com/cgi/content/full/324/7330/144 Competing interests: Professor Joseph Chikelue Obi MBBS MD MPH DSc FRIPH FACAM is also the Chairman of the General Wellness Assembly (GWA); an International Professional Body for Independent Wellness Consultants . He humbly invented the 'Omnipill'. |
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Clarrisa Fonduquet, Clinical Researcher Seattle, Washington , USA
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The fantastic inaugural lecture of Professor Joseph Chikelue Obi on butterbur comes at a time when almost 20% of human beings suffer from at least one unique allergy or another. Let's hope that Professor Obi continues to churn out many more exciting evidence based papers like this, instead of publicly engaging in endless political warfare with his highly opinionated medical seniors. CAM Research sadly lacks a rebellious international ambassador,and is currently a free-for-all specialty. I therefore have absolutely no doubt that Professor Obi will permanently make his radical mark there,without caring thruppence about whose conventional ox get's painfully gored in the process. Professor Joseph Chikelue Obi is certainly the CAM man of the moment, and at the tender young age of 35 he still has more than enough time ahead of him to professionally carry on from where the late Professor David Horrobin sadly stopped. Well done, Professor Obi Competing interests: None declared |
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