Anti-inflammatory activity of an extract of Petasites hybridus in allergic rhinitis

Inhibition of SARS-CoV-2 infection and replication by Petasites hybridus CO2-extract (Ze 339)

BACKGROUND

The intensified search for low-threshold herbal anti-viral drugs would be of great advantage in prevention of early stages of infection. Since the SARS-CoV-2 Omicron variant has prevailed in western countries, the course has only been mild, but there are still no widely available drugs that can alleviate or shorten disease progression and counteract the development of Long-COVID. This study aimed to investigate the antiviral effects of a CO2-extract from Petasites hybridus (Ze 339).

METHODS

We analyzed the infection and replication rate of SARS-CoV-2 in primary normal human bronchial epithelial cells (NHBEs) using a GFP-expressing version of the wild-type SARS-CoV-2 virus and live cell imaging. Upon infection with a clinical isolate of the Omicron variant, viral RNA content was quantified, and plaque assays were performed. In addition, the human transcriptome was analyzed after 4- and 24-hours post infection using whole genome microarrays.

RESULTS

Ze 339 had a protective effect on primary airway epithelial cells during SARS-CoV-2 infection and impeded SARS-CoV-2 infection and replication in NHBE. Notably, Ze 339 inhibited the expression of infection-induced IFNA10 by 8.6-fold (p < 0.05) and additionally reduced a wide range of other interferons (IFNA6, IFNA7, IFNA8, IFNA21, IFNE, IFNW1).

CONCLUSION

Thereby, Ze 339 attenuated epithelial infection by SARS-CoV-2 and modeled the IFN response. In conclusion, this study highlights Ze 339 as a potential treatment option for COVID-19 that limits infection-associated cell intrinsic immune responses.

Application to Butterbur Products of a Suggested Daily Intake-Based Safety Evaluation of Individual Herbal Supplements with Cytochrome P450 Expression as a Major Index

The present paper first proposes a method for ensuring the safety of commercial herbal supplements, termed the suggested daily intake-based safety evaluation (SDI-based safety evaluation). This new method was inspired as a backward analog of the acceptable daily intake (ADI) derivation from the no observed adverse effect level (NOAEL), the basis of food additive risk analysis; namely, rats are dosed with individual herbal supplement products at the SDI for human use multiplied by 100 (the usual uncertainty factor value) per body weight for 8 d. The primary endpoint is the sign of adverse effects on liver, especially gene expression of cytochrome P450 (CYP) isoforms. The proposed method was then applied to three butterbur (Petasites hybridus) products without pyrrolizidine alkaloids but lacking clear safety information. Results showed that two oily products markedly enhanced the mRNA expression of CYP2B (>10-fold) and moderately enhanced that of CYP3A1 (<4-fold) with liver enlargement. These products also caused the renal accumulation of alpha 2-microglobulin. One powdery product showed no significant effect on liver and kidney. The large difference in effects of products was due to the difference in chemical composition revealed by liquid chromatography-mass spectroscopy. The oily and the powdery products required attention in terms of safety and effectiveness, respectively. Finally, the results from the SDI-based safety evaluation of butterbur and other herbal supplement products were grouped into four categories and cautionary notes were discussed. The SDI-based safety evaluation of their products by herbal supplement operators would contribute to safe and secure use by consumers.

Allergies and Natural Alternatives

Complementary and integrative medicine therapies in the treatment of allergy and allergic rhinitis (AR) are divided broadly into the categories of nutritional supplements, herbal supplements, Ayurvedic, and Chinese traditional medicine. Some therapies are likely completely safe, such as Manuka honey, with no known side effects. Others have significant risks, such as ephedra, which was ultimately banned for use by the Food and Drug Administration. The efficacy of these therapies is varied and under-researched. The therapies with the strongest evidence in the treatment of allergy and AR are Manuka honey, butterbur, and Sinupret.

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.

Impact of the clinically approved Petasites hybridus extract Ze 339 on intestinal mechanisms involved in the handling of histamine

In patients with histamine intolerance accumulated or ingested histamine causes a broad range of undesirable symptoms. Food-derived histamine is degraded by intestinal diamine oxidase (DAO) and histamine-N-methyltransferase (HNMT), while the organic cation transporter 3 (OCT3) contributes to the transcellular flux of histamine. Anecdotal evidence from patients with HIT suggests an improvement of symptoms related to histamine intolerance after intake of Ze 339, a lipophilic CO₂-extract prepared from the leaves of Petasites hybridus. Thus, it was the aim of this study to investigate the influence of Ze 339 on DAO, HNMT and OCT3 using Caco-2 and MDCKII cells. Even though Ze 339 reduced mRNA levels of HNMT and DAO, there was no change in protein expression. Ze 339 changed neither the basal release nor the enzymatic activity of DAO. Testing the interaction of Ze 339 with the transcellular histamine transport, we observed a significant increase in the basal to apical flux in presence of high Ze 339 concentrations at the early phases of the experiment. Testing the influence of Ze 339 on OCT3-mediated histamine uptake in overexpressing MDCKII cells revealed a dose-dependent inhibition with an estimated IC₅₀ of 26.9 ug/mL for the extract. In conclusion, we report an effect of Ze 339 on transcellular histamine transport, where inhibition of OCT3 may contribute.

The Petasites hybridus CO2 Extract (Ze 339) Blocks SARS-CoV-2 Replication In Vitro

The coronavirus disease 2019 (COVID-19), caused by a novel coronavirus (SARS-CoV-2), has spread worldwide, affecting over 250 million people and resulting in over five million deaths. Antivirals that are effective are still limited. The antiviral activities of the Petasites hybdridus CO₂ extract Ze 339 were previously reported. Thus, to assess the anti-SARS-CoV-2 activity of Ze 339 as well as isopetasin and neopetasin as major active compounds, a CPE and plaque reduction assay in Vero E6 cells was used for viral output. Antiviral effects were tested using the original virus (Wuhan) and the Delta variant of SARS-CoV-2. The antiviral drug remdesivir was used as control. Pre-treatment with Ze 339 in SARS-CoV-2-infected Vero E6 cells with either virus variant significantly inhibited virus replication with IC₅₀ values of 0.10 and 0.40 μg/mL, respectively. The IC₅₀ values obtained for isopetasin ranged between 0.37 and 0.88 μM for both virus variants, and that of remdesivir ranged between 1.53 and 2.37 μM. In conclusion, Ze 339 as well as the petasins potently inhibited SARS-CoV-2 replication in vitro of the Wuhan and Delta variants. Since time is of essence in finding effective treatments, clinical studies will have to demonstrate if Ze339 can become a therapeutic option to treat SARS-CoV-2 infections.

Extract matrix composition does not affect in vitro leukotriene inhibitory effects of the Petasites hybridus extract Ze 339

It has been shown that a lipophilic CO₂-extract prepared from the leaves of Petasites hybridus (Ze 339) inhibited leukotriene synthesis in vitro and ex vivo. The inhibition of the leukotriene synthesis was solely attributed to the sum of the petasins, namely petasin and its isomers isopetasin and neopetasin. To further investigate the influence of the extract matrix on leukotriene synthesis inhibition, we compared twelve selected batches of Ze 339 that differed significantly in the composition of the extract matrix. Quantitative analysis of the twelve extract batches revealed high contents of petasins [28.8-41.9%], fatty acids [17.1-27.2%] and crude oil and fat [17.7-44.2%]. The amount of sterols ranged between 3.0 and 4.9% and that of essential oils between 1.3 and 10.5%. Based on the quantitative analysis, 97-100% of the extract mass could be attributed to the above mentioned groups of ingredients. Despite significant differences in extract matrix composition, only the content of petasins was critical for the dose-dependent inhibition of leukotriene synthesis. However, at equal concentrations of petasins, no significant differences in 5-LOX, LTC4 synthase and LTA4 hydrolase inhibition were detected between the selected extract batches, despite differences in the composition of the petasin isomers. Our data suggest that the extract matrix of Ze 339 has no effect on leukotriene inhibitory effects of the petasins.

Anti-Allergic Rhinitis Effects of Medicinal Plants and Their Bioactive Metabolites via Suppression of the Immune System: A Mechanistic Review

Allergic rhinitis (AR) is a common inflammatory condition of the nasal mucosa and it is an immunoglobulin E-mediated disease. The incidence and prevalence of AR globally have been escalating over recent years. Antihistamines, intranasal corticosteroids, decongestants, intranasal anticholinergics, intranasal cromolyn, leukotriene receptor antagonists and immunotherapy have been used in the treatment of AR. However, there is a need to search for more effective and safer remedies as many of the current treatments have reported side effects. Medicinal plants have been used traditionally to relief symptoms of AR but their efficacy and safety have not been scientifically proven. In this review, up-to-date reports of studies on the anti-allergic rhinitis of several medicinal plants and their bioactive metabolites through suppression of the immune system are compiled and critically analyzed. The plant samples were reported to suppress the productions of immunoglobulin E, cytokines and eosinophils and inhibit histamine release. The suppression of cytokines production was found to be the main mechanistic effect of the plants to give symptomatic relief. The prospect of these medicinal plants as sources of lead molecules for development of therapeutic agents to treat AR is highlighted. Several bioactive metabolites of the plants including shikonin, okicamelliaside, warifteine, methylwarifteine, luteolin-7-O-rutinoside, tussilagone, petasin, and mangiferin have been identified as potential candidates for development into anti-allergic rhinitis agents. The data collection was mainly from English language articles published in journals, or studies from EBSCOHOST, Medline and Ovid, Scopus, Springer, and Google Scholar databases from the year 1985-2020. The terms or keywords used to find relevant studies were allergic rhinitis OR pollinosis OR hay fever, AND medicinal plant OR single plant OR single herb OR phytotherapy. This comprehensive review serves as a useful resource for medicinal plants with anti-allergic rhinitis potential, understanding the underlying mechanisms of action and for future exploration to find natural product candidates in the development of novel anti-allergic rhinitis agents.

Herbal Medicines for Allergic Rhinitis: a Systematic Review and Meta-analysis

PURPOSE OF REVIEW

To assess the effects of herbal medicine (HM) therapy in various durations and analyze the effects of HM separately by mechanism of action in the treatment of allergic rhinitis (AR).

RECENT FINDINGS

Thirty-two studies were included (2,697 patients, mean age 34.6 years). For the ≤ 4 weeks of treatment duration, HM brought greater benefits over placebo in reduction of total nasal symptoms score (standardized mean difference (SMD) -0.68; 95% confidence interval (CI) -0.98, -0.38; p <0.01) and improvement in Rhinoconjunctivitis Quality of Life Questionnaire score (SMD -0.53; 95% CI -0.81, -0.25; p <0.01). For the 4-12 weeks duration, total nasal symptoms score (SMD -0.22; 95%CI -0.4, -0.05; p =0.01) and Rhinoconjunctivitis Quality of Life Questionnaire score (SMD -0.48; 95% CI -0.89, -0.06; p =0.03) favored the HM. However, HM therapy for longer than 12 weeks was related to tachyphylaxis and showed no benefit over placebo in any outcomes. There was no difference between the HM and standard treatment on symptoms improvement. Anti-allergic effect, anti-inflammatory effect, anti-leukotriene effect, and anti-histaminic effect of HM were revealed. HM was safe and their adverse effects were comparable placebo. HM therapy is safe and provides better results than placebo in improving nasal symptoms and disease-specific quality of life in patients with AR. Its beneficial effects are demonstrated only in less than 12 weeks of treatment.

TRIAL REGISTRATION

PROSPERO ID: CRD42020168367.

Treatment of Early Allergic and Late Inflammatory Symptoms of Allergic Rhinitis with Petasites hybridus Leaf Extract (Ze 339): Results of a Noninterventional Observational Study in Switzerland

The primary objective of this noninterventional, observational study was to assess the effectiveness of the Petasites hybridus leaf extract (Ze 339) on early allergic and late inflammatory symptoms of allergic rhinitis in Swiss outpatients. This study was conducted by general practitioners and allergologists. Data from 226 patients were collected during three documented visits. The intermediate visit was ideally made 2–4 weeks after the baseline visit, followed by the final visit approximately 2–4 months later. The mean study duration was 63 days, with 75% of patients being treated for at least 4 weeks. Of the patients, 58.5% started with Ze 339 monotherapy, and 41.5% received other antiallergic and/or sympathomimetic drugs. In both groups, the allergic total symptom score and the inflammatory total symptom scores were significantly (p < 0.001) reduced, and the scores for quality of life were improved. Both physicians and patients were very satisfied with the treatment and the concept of therapy, not only for short-term (seasonal) therapy but also for long-term therapy. The tolerability was good: only three mild gastrointestinal adverse events occurred. In summary, the effectiveness of P. hybridus leaf extract Ze 339 for the treatment of early allergic and late inflammatory symptoms of allergic rhinitis could be confirmed.

Phytochemistry, Toxicology and Therapeutic Value of Petasites hybridus Subsp. Ochroleucus (Common Butterbur) from the Balkans

Petasites hybridus (Common butterbur) is extensively used in traditional medicine, and is currently gaining interest and popularity as a food supplement and for its medicinal properties. It contains a large number of active compounds of potential therapeutic activity, but also toxic pyrrolizidine alkaloids. Science-based information is needed to support the developing modern use of this plant, and to direct continued safe practice in traditional medicine. The present study focused on the essential oils from leaves and rhizomes of the understudied P. hybridus ssp. ochroleucus from the Balkans, and evaluated its phytochemistry and potential therapeutic activities (antimicrobial, antioxidant, anti-cholinesterase and anti-inflammatory), as well its toxicology potential (acute toxicity in insects and mice). We studied the essential oils, which are not commonly used in traditional practices, but have a potential for safe use since the toxic pyrrolizidine alkaloids, which are non-volatiles, are usually not present in the distilled essential oils. Pyrrolizidine alkaloids were indeed not detected in the essential oils; ingestion of the essential oils did not induce toxicity signs in mice, and topical application did not elicit skin irritation in humans. The essential oils had no antimicrobial properties against 20 pathogenic bacterial strains, but demonstrated good local anti-inflammatory activity in a Carrageenan-induced paw edema test. An insect toxicity test demonstrated that the leaf essential oil is an efficient insect repellent, and the demonstrated anti-cholinesterase activity suggests a potential for the treatment of neurological conditions. Isopetasin, a sesquiterpene found in plants of the genus Petasites, known to have anti-inflammatory effects, was present only in the rhizomes essential oil (3.9%), and sesquiterpene lactones concentrations were high, likely contributing to the antioxidant activity.

In vitro hepatotoxicity of Petasites hybridus extract (Ze 339) depends on the concentration, the cytochrome activity of the cell system, and the species used

Ze 339, a CO₂ extract prepared from the leaves of Petasites hybridus, possesses antispasmodic and anti‐inflammatory effects and is proven to be effective in the treatment of allergic rhinitis. To study possible hepatotoxic effects of Ze 339, its main constituents and metabolites, a series of in vitro investigations were performed. Furthermore, different reconstituted fractions of extract (petasins and fatty acid fraction) were examined in three in vitro test systems using hepatocytes: Two human cell lines, with lower and higher activity of cytochrome P450 enzymes (HepG2, HepaRG) as well as a rodent cell line with high cytochrome P450 activity (H‐4‐II‐E), were used. Metabolic activity, assessed by the WST‐1 assay, was chosen as indicator of cytotoxicity. To assess potential bioactivation of Ze 339 compounds, metabolic experiments using S9 fractions from rats, dogs, and humans and isolated cytochromes (human/rat) were performed, and the formation of reactive metabolites was assessed by measuring cellular concentrations of glutathione and glutathione disulphide.

Our data revealed that the cytotoxicity of Ze 339, its single constituents, and main metabolites depends on the concentration, the cytochrome activity of the cell system, and the species used.

Complementary and Integrative Health Treatments for Migraine

BACKGROUND

Migraine is a chronic disabling neurologic condition that can be treated with a combination of both pharmacologic and complementary and integrative health options.

EVIDENCE ACQUISITION

With the growing interest in the US population in the use of nonpharmacologic treatments, we reviewed the evidence for supplements and behavioral interventions used for migraine prevention.

RESULTS

Supplements reviewed included vitamins, minerals, and certain herbal preparations. Behavioral interventions reviewed included cognitive behavioral therapy, biofeedback, relaxation, the third-wave therapies, acupuncture, hypnosis, and aerobic exercise.

CONCLUSIONS

This article should provide an appreciation for the wide range of nonpharmacologic therapies that might be offered to patients in place of or in addition to migraine-preventive medications.

Effect of Nepeta bracteata Benth. on allergic rhinitis symptoms: A randomized double-blind clinical trial

Background:

Allergic rhinitis (AR) is one of the health problems in the world. It is necessary to develop new treatment procedure for control of this disease. The aim of this study was to assess the effect of Zofa (Nepeta bracteata Benth) on AR patients.

Materials and Methods:

In this double-blind randomized clinical trial study, 71 patients (37 patients in treatment and 34 in placebo group) participated. In treatment group, N. bracteata syrup (NBS) was used for 4 weeks as three times a day. The efficacy of the drug regarding AR symptoms (rhinorrhea, sneezing, nasal obstruction, itchy nose, and ocular symptoms) were evaluated through a visual analog scale (VAS) by 0–10 before administration and at the end of the whole treatment period. The collected information was entered in the SPSS software (version 18) and was analyzed using the Fisher's exact test, Chi-square test, independent sample t-test, and paired sample test.

Results:

The improvement of AR symptoms in the group receiving NBS was significantly higher compared to control group (4.73 ± 1.84 vs. 0.38 ± 2.06; P < 0.0001). Furthermore, the mean of total VAS before and after the treatment (in case group) was 7.10 ± 1.92 and 2.37 ± 1.76, respectively (P < 0.001).

Conclusion:

The results of this study indicate that N. bracteata has significant effects on improving the symptoms of AR. Hence, it can be a good alternative to AR symptoms relief.

Complementary therapies in allergic rhinitis

Objective. To determine the prevalence of herbal treatment of allergic rhinitis. Methods. In this prospective study, patients who were diagnosed with perennial allergic rhinitis were questioned about their use of natural products/herbal therapies for their symptoms. Results. In total, 230 patients were enrolled. Overall, 37.3% of the patients stated that they had used natural products/herbal therapies at least once. Women were more likely than men to use herbal supplements (38.3% versus 32.4%). Ten different types of herbal supplements were identified, with stinging nettle (Urtica dioicath), black elderberry (Sambucus nigra), and Spirulina being the most common (12.6%, 6.1%, and 5.7%, resp.). Conclusion. This study found a high prevalence of herbal treatment usage for the relief of allergic rhinitis symptoms in Turkey. The herbal products identified in this study and in the literature are discussed.

Immunomodulatory effects of 1-(6-hydroxy-2-isopropenyl-1-benzofuran-5-yl)-1-ethanone from Petasites hybridus and its synthesized benzoxazepine derivatives

1-(6-Hydroxy-2-isopropenyl-1-benzofuran-5-yl)-1-ethanone (1), isolated from the roots of Petasites hybridus L., and a series of synthetic benzoxazepine derivatives of compound 1 (2-6) were evaluated for their immunomodulatory effects. The compounds were evaluated for their effects on the respiratory burst of human whole blood and isolated human polymorphonuclear leukocytes (PMNs) using luminol- and lucigenin-based chemiluminescence (CL) assays, and their effect on chemotactic migration of PMNs was assessed using the Boyden chamber technique. Compound 1 exhibited stronger inhibition than acetylsalicylic acid (ASA) on luminol-enhanced CL of PMNs. It also inhibited PMN chemotaxis with an IC50 value comparable to that of ibuprofen. Of the compounds tested, 5 was the most effective in inhibiting luminol-enhanced CL and also strongly inhibited lucigenin-enhanced CL with IC50 values lower than that of ASA. Compound 2 was the most active in inhibiting migration of PMNs and was five times stronger than ibuprofen. The results suggest that compound 1 and its synthesized benzoxazepine derivatives, especially compounds 2 and 5, were able to modulate the innate immune response of phagocytes at different steps, emphasizing their potential as leads for the development of new immunomodulatory agents.

Simultaneous determination of sesquiterpenes and pyrrolizidine alkaloids from the rhizomes of Petasites hybridus (L.) G.M. et Sch. and dietary supplements using UPLC-UV and HPLC-TOF-MS methods

UPLC-UV and HPLC-TOF-MS methods have been developed for the analysis of major sesquiterpenes and pyrrolizidine alkaloids from rhizomes of Petasites hybridus (L.) G.M. et Sch. (Family, Asteracea) and dietary supplements claiming to contain P. hybridus. The best results were obtained with Acquity UPLC™ HSS T3 (100 mm × 2.1 mm, I.D., 1.8 μm) column system using a gradient elution with a mobile phase consisting of ammonium formate (50mM) and acetonitrile (0.05% formic acid) at a constant flow rate of 0.25 mL/min via UPLC-UV. The newly developed method was validated according to the ICH guidelines with respect to specificity, linearity, accuracy and precision. The limits of detection were found to be 5 μg/mL and 0.1 μg/mL for pyrrolizidine alkaloids and sesquiterpenes, respectively by UPLC-UV and 0.001 and 0.01 μg/mL, respectively using HPLC-TOF-MS. The methods were successfully used to analyze different P. hybridus market products, as well as to distinguish between two other Petasites species. The total content of petasins was found to be in the range of 0.02-11.6 mg/dosage form for 15 dietary supplements and no petasins were detected in an additional six dietary supplements. Additionally, pyrrolizidine alkaloids, which are considered to be toxic for the liver, were detected in seven dietary supplements. The amount of petasin in seven dietary supplements was found to be within limits of label claim and no pyrrolizidine alkaloids were detected. HPLC-mass spectrometry coupled with electrospray ionization (ESI) interface method is described for the identification and confirmation of sesquiterpenes and pyrrolizidine alkaloids from plant extracts and dietary supplements that claim to contain P. hybridus as well as different species of Petasites.

Nutraceuticals and headache: the biological basis

Nutrition must affect the structure and functioning of the brain. Since the brain has very high metabolic activity, what we consume throughout the day is likely to dramatically influence both its structure and moment to moment function. It follows that nutritional approaches to all neurological disorders are being researched and entering medical practice, while nutraceutical use is a mainstay of public habits. This review discusses the biological basis for non-conventional or non-mainstream approaches to the treatment of migraine. This requires at least limited discussion of current migraine pathophysiologic theory. How nutrients and other chemicals and approaches are mechanistically involved within migraine pathways is the focus of this article. The nutraceuticals reviewed in detail are: magnesium, riboflavin, coenzyme Q10, petasites, and feverfew with additional comments on marijuana and oxygen/hyperbaric oxygen. This article reviews the science when known related to the potential genetic susceptibility and sensitivity to these treatments. As we know, the basic science in this field is very preliminary, so whether to combine approaches and presumably mechanisms or use them alone or with or without conventional therapies is far from clear. Nonetheless, as more patients and providers participate in patient-centered approaches to care, knowledge of the science underpinning nutritional, nutraceutical, and complementary approaches to treatment for migraine will certainly benefit this interaction.

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.

Anti-allergic effects of total bakkenolides from Petasites tricholobus in ovalbumin-sensitized rats

The anti-allergic effect of total bakkenolides from the rhizome of Petasites tricholobus (BAPT) was evaluated in an ovalbumin-induced allergic rhinitis model in male Wistar rats. The major components of the bakkenolide fraction are bakkenolide-D, bakkenolide-B, bakkenolide-IIIa and bakkenolide-IVa, which account for 60.04% of the total. The rats were treated with 40 mg/kg, 20 mg/kg, 10 mg/kg or 5 mg/kg BAPT, and 0.942 mg/kg loratadine and 0.5% gum tragacanth were used as positive and negative controls, respectively. The frequency of nose rubbing and sneezing was observed, the number of eosinophils infiltrating into the nasal tissue was counted, and serum levels of IL-4 and histamine were determined by ELISA. The results showed that BAPT had a beneficial effect on allergic rhinitis in ovalbumin-sensitized Wistar rats, which was evidenced by a significant decrease in the frequency of sneezing, the number of eosinophils infiltrating into the nasal tissue, and the serum levels of IL-4 and histamine. BAPT may therefore be a potential antiallergic drug.

Antimutagenic and anticarcinogenic effect of methanol extracts of Petasites japonicus Maxim leaves

The methanol extract from the leaves of Petasites japonicus Maxim (PJ) was studied for its (anti-)mutagenic effect with the SOS chromotest and reverse mutation assay. The (anti-)carcinogenic effects were evaluated by the cytotoxicity on human cancer line cells and by the function and the expression of gap junctions in rat liver epithelial cell. PJ extracts significantly decreased spontaneous β-galactosidase activity and β-galactosidase activity induced by a mutagen, ICR, in Salmonella (S.) typhimurium TA 1535/pSK 1002. All doses of the extract (0.08-100 mg/plate) decreased the reversion frequency induced by benzo (α)pyrene (BaP) in S. typhimurium TA 98. It decreased not only the spontaneous reversion frequency but also that induced by BaP in S. typhimurium TA 100. PJ extract showed greater cytotoxic effects on human stomach, colon and uterus cancer cells than on other cancer cell types and normal rat liver epithelial cells. Dye transfers though gap junctions were significantly increased by PJ extracts at concentrations greater than 200 µg/mL and the inhibition of dye transfer by 12-O-tetradecanoylphorobol-13-acetate (TPA) was obstructed in all concentrations of PJ. PJ significantly increased the numbers of gap junction protein connexin 43, and increased the protein expression decreased by TPA in a dose-dependent manner. Based on these findings, PJ is suggested to contain antimutagenic and anticarcionogenic compounds.

Petasites extract Ze 339 (PET) inhibits allergen-induced Th2 responses, airway inflammation and airway hyperreactivity in mice

BACKGROUND

The herbal Petasites hybridus (butterbur) extract (Ze 339, PET) is known to have leukotriene inhibiting properties, and therefore might inhibit allergic diseases.

METHODS

The effect of PET was investigated in ovalbumin (OVA) immunized BALB/c mice given intranasally together with antigen challenge in the murine model of allergic airway disease (asthma) with the analysis of the inflammatory and immune parameters in the lung.

RESULTS

PET given with the antigen challenge inhibited the allergic response. PET inhibited airway hyperresponsiveness (AHR) and eosinophil recruitment into the bronchoalveolar lavage (BAL) fluid upon allergen challenge, but had no effect in the saline control mice. Eosinophil recruitment was further assessed in the lung by eosinophil peroxidase (EPO) activity at a concentration of 100 microg PET. Microscopic investigations revealed less inflammation, eosinophil recruitment and mucus hyperproduction in the lung with 100 microg PET. Diminution of AHR and inflammation was associated with reduced IL-4, IL-5 and RANTES production in the BAL fluid with 30 microg PET, while OVA specific IgE and eotaxin serum levels remained unchanged.

CONCLUSION

PET, which has been reported to inhibit leukotriene activity, reduced allergic airway inflammation and AHR by inhibiting the production of the Th2 cytokines IL-4 and IL-5, and RANTES.

The activity of medicinal plants and secondary metabolites on eosinophilic inflammation

Eosinophils are leukocytes that are present in several body compartments and in the blood at relatively low numbers under normal conditions. However, an increase in the number of eosinophils, in the blood or in the tissues, is observed in allergic or parasitic disorders. Although some progress has been made in understanding the development of eosinophil-mediated inflammation in allergic and parasitic diseases, the discovery of new compounds to control eosinophilia has lagged behind other advances. Plant-derived secondary metabolites are the basis for many drugs currently used to treat pathologic conditions, including eosinophilic diseases. Several studies, including our own, have demonstrated that plant extracts and secondary metabolites can reduce eosinophilia and eosinophil recruitment in different experimental animal models. In this review, we summarize these studies and describe the anti-eosinophilic activity of various plant extracts, such as Ginkgo biloba, Allium cepa, and Lafoensia pacari, as well as those of secondary metabolites (compounds isolated from plant extracts), such as quercetin and ellagic acid. In addition, we highlight the medical potential of these plant-derived compounds for treating eosinophil-mediated inflammation, such as asthma and allergy.

Red wine polyphenolic compounds inhibit tracheal smooth muscle contraction during allergen-induced hyperreactivity of the airways

The aims of the study were to investigate the short and long-term effects of Provinol (red wine polyphenolic compounds) on tracheal smooth muscle reactivity using an in-vitro model of ovalbumin-induced airway inflammation in guinea-pig trachea, and to evaluate the role of nitric oxide (NO) in the bronchodilatory effect of Provinol.

The amplitude of tracheal smooth muscle contraction in response to mediators of bronchoconstriction —histamine (10 nM-1 mM), acetylcholine (10 nM-1 mM) and to allergen (ovalbumin 10−5-10−3 g mL−1) was used as a parameter of tracheal smooth muscle reactivity. To test the short-term effects of Provinol, isolated tracheal strips were pre-treated for 30 min with Provinol (10−4mg mL−1) alone or in combination with Nω-nitro-L-arginine methyl ester (L-NAME; 10−6mol L−1). To test the long-term effects of Provinol, isolated tracheal strips were prepared from guinea pigs that had been treated for 14 days with Provinol (20mg kg−1 per day) alone or in combination with L-NAME (40 mg kg−1 per day).

Incubation of tracheal smooth muscle with Provinol decreased the amplitude of contraction in response to ovalbumin, histamine and acetylcholine. The non-selective NO synthase inhibitor L-NAME partially abolished the effect of Provinol on acetylcholine and ovalbumin-induced but not histamine-induced bronchoconstriction. A similar profile was observed after 14 days' oral administration of Provinol.

In conclusion, Provinol inhibited the allergen- and spasmogen-induced contraction of tracheal smooth muscle in ovalbumin-sensitized guinea pigs via a mechanism that was mediated at least partially through the metabolism of NO.

Effects of a new nutraceutical ingredient on allergen-induced sulphidoleukotrienes production and CD63 expression in allergic subjects

Allergic diseases represent conditions affecting millions of individuals across the world. The objective of this study was to investigate the potential anti-allergic effects of a new nutraceutical ingredient, Pantescal (Bionap, Italy), contained in different food supplements. Pantescal is a mixture of plant extracts, such as Capparis spinosa, Olea europaea, Panax Ginseng and Ribes nigrum. The study was a randomized, double-blind, placebo controlled design. 60 patients allergic to common aeroallergens were chosen. Allergic patients were divided into two groups: one group was supplemented by Pantescal and the other, using a placebo formulation. Two in vitro tests were performed on blood samples taken from patients before and at 2 h, 2, 3 and 10 days after supplementation: cellular antigen stimulation test (CAST) was used to analyze the amount of sulphidoleukotrienes (SLT) production and flow-cytometric antigen stimulation test (FAST) to measure expression of basophil degranulation marker (CD63) was also performed. CAST showed that after 2 and 3 days, a slight decrease of SLT production was evident but only after 10 days did it become significant with a percentage of inhibition (P.I)=43.3%. FAST revealed that there were no statistical differences for the first 2 days after supplementation although there was an inhibitory trend in the supplemented patients. CD63 expression was significantly reduced after 10 days (P.I.=64.8%). This study suggests that Pantescal is effective in reducing allergic biomarkers such as CD63 protein and SLT in atopic subjects. The higher inhibitory effect on CD63 expression compared to SLT production allows us to hypothesize cell membrane stabilization as the main potential mechanism to explain the observed Pantescal protective effects.

Herbal medicines for the treatment of allergic rhinitis: a systematic review

OBJECTIVE

To evaluate the efficacy of herbal medicines for the treatment of allergic rhinitis (AR).

DATA SOURCES

Five electronic databases until November 8, 2005; bibliographies of located articles; manufacturers of commercially available preparations; and experts in the field.

STUDY SELECTION

We only included double-blind randomized clinical trials (RCTs), which tested a herbal medicine against placebo or active comparator, in patients with AR, and evaluated clinically relevant outcomes. Study selection, data extraction, and evaluation of methodological quality were performed independently by 2 reviewers. Discrepancies were resolved by discussion and by seeking the opinion of the third reviewer. Meta-analysis was only performed if data were considered suitable for pooling.

RESULTS

Sixteen eligible RCTs, testing 10 different herbal products against placebo or active comparator, were included. Six RCTs studied Petasites hybridus (butterbur) extract for AR and suggest that P hybridus is superior to placebo or similarly effective compared with nonsedative antihistamines for intermittent AR. Two RCTs studied an Indian herbal combination, Aller-7, in patients with AR and reported positive results. Single RCTs were identified for 8 other herbal products as treatments for AR, reporting positive outcomes, except for grape seed extract. The median methodological quality score was 4 of a possible maximum of 5.

CONCLUSIONS

There is encouraging evidence suggesting that P hybridus may be an effective herbal treatment for seasonal (intermittent) AR. However, independent replication is required before a firm conclusion can be drawn because of the financial support from the manufacturer of P hybridus extract to the 3 large trials. There are also promising results generated for other herbal products, particularly Aller-7, Tinospora cordifolia, Perilla frutescens, and several Chinese herbal medicines. Although these results are confined to the paucity of data and the small sample size, confirmation in larger and more rigorously designed clinical trials is warranted.

Immunological functions of soy sauce: hypoallergenicity and antiallergic activity of soy sauce

Soy sauce is a traditional fermented seasoning of East Asian countries and is available throughout the world. In Japanese soy sauce (shoyu), soybeans and wheat are the two main raw materials, used in almost the same quantity. Proteins of the raw materials are completely degraded into peptides and amino acids by microbial proteolytic enzymes after fermentation, and no allergens of the raw materials are present in soy sauce. In contrast, polysaccharides originating from the cell wall of soybeans are resistant to enzymatic hydrolyses. These polysaccharides are present in soy sauce even after fermentation and termed shoyu polysaccharides (SPS). Soy sauce generally contains about 1% (w/v) SPS and SPS exhibit potent antiallergic activities in vitro and in vivo. Furthermore, an oral supplementation of SPS is an effective intervention for patients with allergic rhinitis in two double-blind placebo-controlled clinical studies. In conclusion, soy sauce would be a potentially promising seasoning for the treatment of allergic diseases through food because of its hypoallergenicity and antiallergic activity.

Inhibition of Mast Cell‐Dependent Allergy Reaction by Extract of Black Cohosh (Cimicifuga racemosa)

Black cohosh (Cimicifuga racemosa) has been used as therapeutics for pain and inflammation in Korean folk medicine. The potential effects of black cohosh extract (BCE) on mast cell-dependent allergy reaction, however, have not been well elucidated yet. In the present study, we investigated the effect of BCE on the allergy reaction using mast cell-dependent in vivo and in vitro models. BCE showed no potential of skin sensitization in local lymph node assay (LLNA). The oral administration of BCE significantly inhibited the anti-IgE-induced passive cutaneous anaphylaxis (PCA) reaction. BCE also showed inhibitory potential on the compound 48/80-induced histamine release from rat peritoneal mast cells. In addition, BCE inhibited the IL-4, IL-5 and TNF-alpha mRNA induction by PMA and A23187 in human leukemia mast cells, HMC-1. These results demonstrated that BCE has an anti-allergic potential and it may be due to the inhibition of histamine release and cytokine gene expression in the mast cells.

Mast cells and mast cell mediators as targets of dietary supplements

OBJECTIVE

To review the increasing amount of data that support or dispel the use of dietary supplements in the treatment of inflammatory conditions that involve mast cells, such as allergies, arthritis, and chronic pelvic pain syndrome.

DATA SOURCES

A search was conducted in MEDLINE for natural substances, dietary supplements, flavonoids, and proteoglycans for their in vitro or in vivo effects on allergic and inflammatory conditions.

STUDY SELECTION

Studies were selected for inclusion because of the impact factor of the journal, the definitive nature of the findings, the soundness of the study design, and the expert opinion of the authors.

RESULTS

Dietary supplements include a large group of products, such as vitamins, minerals, plant, or animal extracts, as well as herbal preparations that are often called medicinal herbs. Many of the available dietary supplements contain a multitude of ingredients, the source and/or purity of which is seldom disclosed; some of these may have biologic effects of their own or may interact with other supplements or drugs, often leading to adverse effects. The most well-documented evidence published to date is on the inhibitory action of natural compounds, especially flavonoids, on mast cells and allergic symptoms. Some flavonoids have weak inhibitory activity, whereas others may have no benefit or may be detrimental. Sulfated proteoglycans could provide synergistic action but require formulations with increased absorption.

CONCLUSIONS

Combining the most active flavonoids with proteoglycans could be helpful in atopic and inflammatory conditions. However, a complete list of active ingredients and their source, purity, and exact concentration should be a requirement for nutraceuticals to standardize, compare, and promote their safe use.

A placebo-controlled evaluation of butterbur and fexofenadine on objective and subjective outcomes in perennial allergic rhinitis

BACKGROUND

There are presently no placebo-controlled data regarding the effects of butterbur (BB) on subjective and objective outcomes in patients with perennial allergic rhinitis.

OBJECTIVE

We performed a placebo-controlled evaluation of the effects of BB and fexofenadine (FEX) on subjective and objective outcomes in patients with perennial allergic rhinitis.

METHODS

Sixteen patients with perennial allergic rhinitis and house dust mite sensitization were randomized in double-blind cross-over fashion to receive for 1 week either BB 50 mg twice daily, FEX 180 mg once daily and placebo (PL) once daily, or PL twice daily. The peak nasal inspiratory flow (PNIF) response to adenosine monophosphate (AMP) challenge administered as a single 400 mg/mL dose was measured over a 60-min period after challenge, and domiciliary total nasal symptom score was recorded.

RESULTS

Pre-challenge values for mean+/-SEM PNIF (L/min) were not significantly different comparing all groups; BB (138+/-8), FEX (140+/-9), and PL (138+/-8). The maximum % PNIF fall from baseline after nasal AMP challenge was significantly attenuated (P<0.05) compared to PL (46+/-3), with BB (34+/-3) and FEX (39+/-3). The area under the 60-min time-response curve (%.min) was also significantly attenuated (P<0.05) compared to PL (1734+/-156), with BB (1052+/-258) and FEX (1194+/-161). There was also a significant reduction (P<0.05) in total nasal symptom score with BB (1.8+/-0.4) and FEX (1.8+/-0.4), compared to PL (2.8+/-0.5). There were no significant differences between BB and FEX for any outcomes.

CONCLUSION

BB and FEX, in comparison to PL, were equally effective in attenuating the nasal response to AMP and in improving nasal symptoms, highlighting a potential role for BB in the treatment of allergic rhinitis.

Rosmarinic acid in perilla extract inhibits allergic inflammation induced by mite allergen, in a mouse model

BACKGROUND

Perilla and its constituent rosmarinic acid have been suggested to have anti-allergic activity. However, few studies have examined the effects on allergic asthma.

OBJECTIVE

The purpose of this study was to evaluate the effect of oral administration of perilla leaf extract, which contains high amount of rosmarinic acid, on a murine model of allergic asthma induced by house dust mite allergen.

METHODS

C3H/He mice were sensitized by intratracheal administration of Dermatophagoides farinae (Der f). Mice were orally treated with rosmarinic acid in perilla extract (PE) (1.5 mg/mouse/day).

RESULTS

Der f challenge of sensitized mice elicited pulmonary eosinophilic inflammation, accompanied by an increase in lung expression of IL-4 and IL-5, and eotaxin. Daily treatment with rosmarinic acid in PE significantly prevented the increases in the numbers of eosinophils in bronchoalveolar lavage fluids and also in those around murine airways. Rosmarinic acid in PE treatment also inhibited the enhanced protein expression of IL-4 and IL-5, and eotaxin in the lungs of sensitized mice. Der f challenge also enhanced allergen-specific IgG1, which were also inhibited by rosmarinic acid in PE.

CONCLUSION

These results suggest that oral administration of perilla-derived rosmarinic acid is an effective intervention for allergic asthma, possibly through the amelioration of increases in cytokines, chemokines, and allergen-specific antibody.

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

BACKGROUND

The effects of butterbur (BB), a herbal remedy, as add-on therapy to inhaled corticosteroids in patients with atopic asthma is currently unknown.

OBJECTIVE

We evaluated the effects of BB, given as add-on therapy to asthmatic patients maintained on inhaled corticosteroids, assessing adenosine monophosphate (AMP) bronchoprovocation (primary outcome variable) along with other surrogate inflammatory markers such as exhaled nitric oxide, serum eosinophil cationic protein and peripheral blood eosinophil count.

METHODS

Sixteen atopic asthmatic patients with mean (standard error of mean) forced expiratory volume in 1 s (FEV1) of 78 (4)% predicted, maintained on their constant dose of inhaled corticosteroids throughout the study, received twice daily for 1 week either BB 25 mg or placebo (PL), in a double-blind, cross-over fashion, with a 1-week washout period prior to each randomized treatment. Measurements were made at baselines prior to each randomized treatment and following the randomized treatment period.

RESULTS

Baseline values for the primary and secondary outcomes were not significantly different prior to BB and PL. AMP provocative concentration causing a 20% reduction from baseline FEV1 (PC20) as doubling dilution change from baseline, significantly improved (P<0.05) with BB, 0.6 (0.2), compared with PL, -0.1 (0.3); a 0.7 doubling dilution difference. Exhaled nitric oxide as change from baseline was significantly reduced (P<0.05) with BB, -1.2 (0.8) p.p.b., compared with PL, 0.5 (0.4) p.p.b. Both serum eosinophil cationic protein and peripheral blood eosinophil count as change from baseline were also significantly suppressed (P<0.05) with BB, -3.9 (3.3) microg/L, -31 (28)x106/L compared with PL, 3.3 (2.5) microg/L, 38 (16)x106/L, respectively.

CONCLUSION

Chronic dosing with BB conferred complementary anti-inflammatory activity in atopic asthmatic patients maintained on inhaled corticosteroids. Further studies are now required to assess the potential role for BB as either monotherapy in milder patients or add-on therapy in more severe asthmatics.

The effects of butterbur on the histamine and allergen cutaneous response

BACKGROUND

Butterbur or Petasites hybridus is an herbal remedy that exhibits antihistamine and antileukotriene activity and has been shown to attenuate the response to adenosine monophosphate challenge in patients with allergic rhinitis and asthma. However, no data are available regarding its effects on the histamine and allergen cutaneous response.

OBJECTIVE

To evaluate the effects of butterbur compared with fexofenadine and montelukast on the histamine and allergen wheal and flare cutaneous responses.

METHODS

Atopic patients were randomized into a double-blind, double-dummy, crossover study to receive for 1 week butterbur, 50 mg twice daily (8 AM and 10 PM); fexofenadine, 180 mg once daily (10 PM), and placebo once daily (8 AM); montelukast, 10 mg once daily (10 PM), and placebo once daily (8 AM); or placebo twice daily (8 AM and 10 PM). Patients attended the department at 10 AM and had measurements of the cutaneous wheal and flare responses to histamine, allergen, and saline control at 10-minute intervals for 60 minutes.

RESULTS

Twenty patients completed the study. The mean +/- SE histamine wheal and flare responses, respectively, were significantly attenuated (P < .05) by fexofenadine (9.4 +/- 1.8 mm2 and 13.5 +/- 3.2 mm2) compared with placebo (15.5 +/- 3.3 mm2 and 179.8 +/- 74.3 mm2) but not by butterbur (16.4 +/- 2.1 mm2 and 297.7 +/- 121.2 mm2) or montelukast (19 +/- 1.9 mm2 and 240.2 +/- 66.6 mm2). The allergen wheal and flare responses, respectively, were also significantly attenuated (P < .05) by fexofenadine (31.1 +/- 6.3 mm2 and 256.9 +/- 86.5 mm2) compared with placebo (65.4 +/- 15.2 mm2 and 1,014.5 +/- 250.0 mm2) but not by butterbur (50.4 +/- 9.2 mm2 and 1,110.3 +/- 256.1 mm2) or montelukast (58.8 +/- 9.1 mm2 and 1,463.6 +/- 295.6 mm2).

CONCLUSIONS

Butterbur did not produce any significant effects on the histamine and allergen cutaneous response compared with placebo, whereas mediator antagonism with fexofenadine but not montelukast produced significant attenuation. This finding would suggest that butterbur may not be effective in allergic skin disease.

Clinical and immunological effects of low-dose IFN-alpha treatment in patients with corticosteroid-resistant asthma

BACKGROUND

Interferon (IFN)-alpha is a cytokine that possesses potent anti-viral and immunoregulatory activities. We aimed to assess clinical and immunological effects of low-dose IFN-alpha in patients with severe corticosteroid-resistant asthma with and without Churg-Strauss syndrome. There is currently no efficient pharmacological treatment available for this group of patients.

METHODS

We studied 10 patients with corticosteroid-resistant asthma, in which 3x10(6) IU/day IFN-alpha were administrated in addition to the prednisone dose given already before introduction of the cytokine therapy. The prednisone dose was gradually reduced dependent on the clinical situation and used as a clinical readout to evaluate the efficacy of the cytokine therapy. To distinguish between IFN-alpha- and prednisone-mediated immunological changes, the corticosteroid dose was kept constant for at least 2 weeks upon introduction of the cytokine therapy in seven patients. The effects of treatment on clinical and immunological parameters were measured at 2-4 weeks and 5-10 months depending on the availability of the patient.

RESULTS

Interferon-alpha treatment rapidly improved the clinical situation as assessed by lung function parameters and required prednisone dose. Important immunological changes included: decreased leukocyte numbers, increased relative numbers of CD4+ T cells, increased differentiation of T helper (Th)1 cells, and increased expression of interleukin (IL)-10 in peripheral blood mononuclear cells.

CONCLUSION

Interferon-alpha treatment was associated with dramatic improvements in the condition of patients with corticosteroid-resistant asthma with and without Churg-Strauss syndrome. Potential mechanisms of action include the establishment of a correct Th1/Th2 balance and the induction of the anti-inflammatory IL-10 gene.

Butterbur, a herbal remedy, attenuates adenosine monophosphate induced nasal responsiveness in seasonal allergic rhinitis

BACKGROUND

Butterbur (BB) or Petasites hybridus, a herbal remedy, exhibits in vitro inhibition of cysteinyl leukotriene biosynthesis. However, no placebo-controlled studies have been performed to evaluate the effectiveness of BB on objective outcomes such as nasal provocation testing in seasonal allergic rhinitis (SAR).

METHODS

Twenty patients with grass-pollen-sensitized SAR were randomized in a double-blind, cross-over manner to receive for 2 weeks either BB 50 mg twice daily or placebo (PL) twice daily during the grass pollen season. Nasal adenosine monophosphate (AMP) challenge (the primary outcome) was administered as a single 400 mg/mL dose after each randomized treatment.

RESULTS

Spontaneous recovery following AMP challenge (area under the response time profile curve as % x min+/-SEM) was significantly attenuated (P=0.028) with BB (584+/-289) compared to PL (1438+/-240); mean difference: 854 (95% CI 95-1614), and the maximum % peak nasal inspiratory flow reduction from baseline following AMP challenge was significantly blunted (P=0.036) with BB (30+/-4) compared to PL (43+/-5); mean difference: 13 (95% CI 1-25).

CONCLUSIONS

BB exhibited protection against AMP-induced nasal responsiveness during the grass pollen season in sensitized patients. This is turn may explain its potential clinical efficacy in patients with SAR.

Petasins in the treatment of allergic diseases: results of preclinical and clinical studies

Plant extracts are causing an increased interest in the treatment of many chronic diseases, including asthma and other allergic diseases. Several laboratories characterized petasins (petasin, isopetasin, and neopetasin) isolated from extracts of butterbur (Petasites hybridus) as pharmacologically active components, which inhibit leukotriene synthesis in leukocytes. The molecular mechanisms by which petasins abrogate inflammatory effector cell functions have, at least partially, been identified. In vitro studies revealed that petasins may have several intracellular targets and this may depend on the stereoisomer used. In an open clinical trial in patients suffering from allergic rhinitis, a reduction of leukotriene and histamine levels in nasal fluids was associated with the butterbur extract administration. To better evaluate the clinical value in this particular allergic disease, the clinical efficacy of the drug was compared with an established antihistamine treatment scheme in a double-blind study; no significant difference was observed between the two treatment groups. In this article, we critically review recently published work and summarize the current stage in the pharmacological characterization of butterbur extracts.