Anti-inflammatory activity of 1.8-cineol (eucalyptol) in bronchial asthma: a double-blind placebo-controlled trial

Phytomedicine in otorhinolaryngology and pulmonology: clinical trials with herbal remedies

Phytomedicine has become an important alternative treatment option for patients in the Western world, as they seek to be treated in a holistic and natural way after an unsatisfactory response to conventional drugs. Ever since herbal remedies have been introduced in the Western world, clinicians have raised concerns over their efficacy and possible side-effects. A PubMed (Medline) search was performed covering the last five years (01/07-04/12) and including 55 prospective clinical randomized control trials in the medical specialities Otorhinolaryngology and Pulmonology. In this review, we present evidence-based clinical data with herbal remedies and try to enlighten the question of efficacy and reliability of phytomedicine.

Cloning, functional characterization and genomic organization of 1,8-cineole synthases from Lavandula

Several members of the genus Lavandula produce valuable essential oils (EOs) that are primarily constituted of the low molecular weight isoprenoids, particularly monoterpenes. We isolated over 8,000 ESTs from the glandular trichomes of L. x intermedia flowers (where bulk of the EO is synthesized) to facilitate the discovery of genes that control the biosynthesis of EO constituents. The expression profile of these ESTs in L. x intermedia and its parents L. angustifolia and L. latifolia was established using microarrays. The resulting data highlighted a differentially expressed, previously uncharacterized cDNA with strong homology to known 1,8-cineole synthase (CINS) genes. The ORF, excluding the transit peptide, of this cDNA was expressed in E. coli, purified by Ni-NTA agarose affinity chromatography and functionally characterized in vitro. The ca. 63 kDa bacterially produced recombinant protein, designated L. x intermedia CINS (LiCINS), converted geranyl diphosphate (the linear monoterpene precursor) primarily to 1,8-cineole with K ( m ) and k ( cat ) values of 5.75 μM and 8.8 × 10(-3) s(-1), respectively. The genomic DNA of CINS in the studied Lavandula species had identical exon-intron architecture and coding sequences, except for a single polymorphic nucleotide in the L. angustifolia ortholog which did not alter protein function. Additional nucleotide variations restricted to L. angustifolia introns were also observed, suggesting that LiCINS was most likely inherited from L. latifolia. The LiCINS mRNA levels paralleled the 1,8-cineole content in mature flowers of the three lavender species, and in developmental stages of L. x intermedia inflorescence indicating that the production of 1,8 cineole in Lavandula is most likely controlled through transcriptional regulation of LiCINS.

Topical antiinflammatory activity of essential oil of Lippia sidoides cham: possible mechanism of action

This work reports the chemical composition of the essential oil of Lippia sidoides (EOLS) and evaluation of the topical effect of EOLS and thymol against different irritant agents in vivo. The essential oil was obtained by hydrodistillation, and gas chromatography/mass spectrometry analysis identified the main constituents: thymol (84.9%) and p-cymene (5.33%). The antiinflammatory activity was evaluated using the mouse models of acute ear inflammation induced by croton oil, arachidonic acid, phenol or histamine, and chronic inflammation induced by croton oil. The topical application of EOLS or thymol at a dose of 2 mg/ear significantly reduced (p < 0.001) ear edema induced with arachidonic acid by 45.1% and 47.4% and reduced ear edema induced with phenol by 33.2% (p < 0.05) and 54.7% (p < 0.01) in acute ear edema. However, a proinflammatory effect of EOLS and thymol was evidenced when it was applied for more than 1 day. There were no statistical differences in antiedematogenic activity between EOLS and thymol. In conclusion, the results indicate that thymol is the constituent responsible for the topical antiinflammatory activity of EOLS. Thus, these findings could justify the popular use of L. sidoides by alternative medicine, but chronic use has an inflammatory effect.

Salvia officinalis L. essential oils: effect of hydrodistillation time on the chemical composition, antioxidant and antimicrobial activities

Salvia officinalis L. oils were isolated from the plant's commercial dried aerial parts, by hydrodistillation, with different distillation times. The essential oils were analysed by gas chromatography and gas chromatography-mass spectrometry. The antioxidant ability was measured using a free radical scavenging activity assay using 2,2-diphenyl-1-picrylhydrazyl (DPPH), a thiobarbituric acid reactive substances (TBARS) assay, a deoxyribose assay for the scavenging of hydroxyl radical, an assay for site-specific actions and a 5-lipoxygenase assay. Antibacterial activity was determined by the agar diffusion method. 1,8-Cineole, α-pinene and camphor were the dominant components of all the essential oils. The different hydrodistillation times did not affect the oil yield nor the relative amount of the oil components. The time of hydrodistillation influenced the antioxidant activity. With the DPPH method, the oils isolated for 2 and 3 h were stronger free radical scavengers, while with the TBARS method, the highest antioxidant values were obtained in the oils isolated for 30 min, 2 and 3 h. Hydroxyl radical scavenging and lipoxygenase activity assays showed the best results with oils isolated for 1 and 3 h. With the deoxyribose method, sage oils at concentrations <1000 mg L(-1) showed better activity than mannitol. The essential oil of S. officinalis showed very weak antimicrobial activity.

Comparison of Eucalyptus cinerea Essential Oils Produced by Hydrodistillation and Supercritical Carbon Dioxide Extraction

The essential oil of Eucalyptus cinerea is reported to possess a higher 1,8-cineole content than other Eucalyptus species. Variations in the quantitative and qualitative characteristics of E. cinerea oil produced by hydrodistillation (HD) and supercritical carbon dioxide extraction (SCE) techniques and a comparison between glycoside-bound and free volatile constituents produced by HD have been studied. It was found that HD produced higher oil (free volatiles) content (3.1%) as compared with SCE (1.1%), whereas bound volatiles constituted only about 0.4%. Gas chromatographic (GC) analysis of the oil samples revealed significant difference in their chemical composition. The essential oil (free volatiles) produced by HD contained 1,8-cineole (85.1%) as the major constituent, followed by α-terpineol (7.2%) and limonene (4.4%). In the bound volatile fraction produced by HD, 1,8 cineole (20.6%), α-terpineol (7.6%), p-cymene (6.3%), and limonene (4.5%) were found as major constituents. The extract produced by SCE was dominated by 1,8-cineole (70.4%), α-terpineol (8.6%), globulol (3.1%), aromadendrene (2%), citronellal (1.7%), viridiflorol (1.3%), phytol (1.1%) and terpinen-4-ol (1%). Although HD produced higher oil yields, SCE produced better extract in terms of the number of components detected.

Chemical diversity in the genus Alpinia (Zingiberaceae): comparative composition of four Alpinia species grown in Northern India

The essential-oil compositions of leaves, flowers, and rhizomes of Alpinia galanga (L.) Willd., Alpinia calcarata Rosc., Alpinia speciosa K. Schum., and Alpinia allughas Rosc. were examined and compared by capillary GC and GC/MS. Monoterpenoids were the major oil constituents identified. 1,8-Cineole, alpha-terpineol, (E)-methyl cinnamate, camphor, terpinen-4-ol, and alpha- and beta-pinenes were the major constituents commonly distributed in leaf and flower essential oils. The presence of endo-fenchyl acetate, exo-fenchyl acetate, and endo-fenchol was the unique feature of rhizome essential oils of A. galanga, A. calcarata, and A. speciosa. On contrary, the rhizome oil of A. allughas was dominated by beta-pinene. Significant qualitative and quantitative variations were observed in essential-oil compositions of different parts of Alpinia species growing in subtemperate and subtropical regions of Northern India. Cluster analysis was performed to find similarities and differences in essential-oil compositions based on representative molecular skeletons. Monoterpenoids, viz., 1,8-cineole, terpinen-4-ol, camphor, pinenes, (E)-methyl cinnamate, and fenchyl derivatives, were used as chemotaxonomic markers.

Inhaled 1,8-cineole reduces inflammatory parameters in airways of ovalbumin-challenged Guinea pigs

Eucalyptol, also known as 1,8-cineole, is a monoterpene traditionally used to treat respiratory disorders due to its secretolytic properties. In addition to its myorelaxant effects, it also has anti-inflammatory actions in vitro. In this study, we aimed to evaluate the efficacy of acute treatment with 1,8-cineole on reducing airway inflammatory parameters. Ovalbumin (OVA)-sensitized guinea pigs were submitted to antigenic challenge (OVA) with or without pre-treatment with a single dose of 1,8-cineole administered by inhalation. Airway inflammatory parameters were reduced or absent in 1,8-cineole-treated animals as compared with untreated guinea pigs. Acute treatment with 1,8-cineole impaired the development of airway hyperresponsiveness to carbachol in isolated tracheal rings. Levels of the pro-inflammatory cytokines TNFα and IL-1β was lower in bronchoalveolar lavage fluid (BALF) of 1,8-cineol-treated guinea pigs than in untreated animals. 1,8-Cineole impaired the OVA-induced increase of the myeloperoxidase activity in BALF. 1,8-Cineole also prevented the reduction of the mucociliary clearance induced by the antigen presentation. The present investigation provides evidence that inhaled 1,8-cineole prevents hyperresponsiveness and inhibits inflammation in airways of ovalbumin-challenged guinea pigs.

Pediatric asthma: an integrative approach to care

Asthma in children and young adults is a complex disease with many different phenotypic expressions. Diagnosis is often made based on history and lung function including measuring airway reversibility. However, in children younger than 6 years of age, the diagnosis is more difficult because many children wheeze in the first 4-6 years of life, especially with viral infections. For those children, asthma treatment is often started empirically. Those who go on to develop chronic asthma most likely have a genetic predisposition and exposure to various environmental factors resulting in chronic inflammation of the lower respiratory tract. There are established national guidelines for diagnosing and treating asthma in children and adults. For persistent asthma, it is recommended that medications be taken on a regular basis after identifying and avoiding environmental triggers. Because many factors play a role in developing asthma in children, many nonmedical approaches to asthma and asthma-like conditions have been promoted even when the diagnosis is at times uncertain. The nonmedical approaches and therapies are often referred to as complementary and alternative medicine (CAM). This review will discuss the conventional therapies recommended for children with asthma in addition to CAM therapies, some of which have supporting scientific evidence. Integrating conventional and CAM therapies can prove to be an effective way to treat pediatric asthma, a common and chronic childhood lung disorder. A case is provided to illustrate how such an integrative approach was used in the successful treatment of a child with moderate persistent asthma.

Protective Effects of the Essential Oil of Salvia fruticosa and Its Constituents on Astrocytic Susceptibility to Hydrogen Peroxide-Induced Cell Death

Oxidative stress has been implicated in pathologic processes associated with neurodegenerative diseases. Astrocytes, the most abundant glial cell type in the brain, protect neurons from reactive oxygen species (ROS), and any damage to them will affect neuronal survival. This study compares the ability of essential oils prepared from different herbs and spices to protect cultured primary brain astrocytes from H2O2-induced death. The results show that the essential oil of Salvia fruticosa (Sf) among the tested essential oils demonstrated remarkable protective activity. The protective effect of Sf could be attributed to alpha-humulene and alpha-pinene. Following incubation, alpha-humulene and trans-beta-caryophyllene could be found in the cytosol of astrocytes. It is proposed that Sf, by attenuating H2O2-induced cell death, might be used as a functional food or may be offered as a means of therapy in the treatment of neurodegenerative diseases.

Concomitant therapy with Cineole (Eucalyptole) reduces exacerbations in COPD: a placebo-controlled double-blind trial

Background

The clinical effects of mucolytics in patients with chronic obstructive pulmonary disease (COPD) are discussed controversially. Cineole is the main constituent of eucalyptus oil and mainly used in inflammatory airway diseases as a mucolytic agent. We hypothesised that its known mucolytic, bronchodilating and anti-inflammatory effects as concomitant therapy would reduce the exacerbation rate and show benefits on pulmonary function tests as well as quality of life in patients with COPD.

Methods

In this double-blind, placebo-controlled multi-center-study we randomly assigned 242 patients with stable COPD to receive 200 mg of cineole or placebo 3 times daily as concomitant therapy for 6 months during winter-time. The frequency, duration and severity of exacerbations were combined as primary outcome measures for testing as multiple criteria. Secondary outcome measures included changes of lung function, respiratory symptoms and quality of life as well as the single parameters of the exacerbations.

Results

Baseline demographics, lung function and standard medication of both groups were comparable. During the treatment period of 6 months the multiple criteria frequency, severity and duration of exacerbations were significantly lower in the group treated with cineole in comparison to placebo. Secondary outcome measures validated these findings. Improvement of lung function, dyspnea and quality of life as multiple criteria were statistically significant relative to placebo. Adverse events were comparable in both groups.

Conclusion

Concomitant therapy with cineole reduces exacerbations as well as dyspnea and improves lung function and health status. This study further suggests cineole as an active controller of airway inflammation in COPD by intervening in the pathophysiology of airway inflammation of the mucus membrane.

Trial registration

ISRCTN07600011

Effects of 1,8-cineole on electrophysiological parameters of neurons of the rat superior cervical ganglion

1. 1,8-Cineole is a non-toxic small terpenoid oxide believed to have medicinal properties in folk medicine. It has been shown to have various pharmacological effects, including blockade of the compound action potential (AP). In the present study, using intracellular recording techniques, we investigated the effects of 1,8-cineole on the electrophysiological parameters of neurons of the superior cervical ganglion (SCG) in rats. 2. 1,8-Cineole (0.1-6 mmol/L) showed reversible and concentration-dependent effects on various electrophysiological parameters. At 3 and 6 mmol/L, but not at 0.1 and 1 mmol/L, 1,8-cineole significantly diminished the input resistance (R(i)) and altered the resting potential (E(m)) to more positive values. At 6 mmol/L, 1,8-cineole completely blocked all APs within 2.7 +/- 0.6 min (n = 12). In neurons exposed to 3 and 1 mmol/L 1,8-cineole, the effects regarding excitability varied from complete AP blockade to minor inhibition of AP parameters. The depolarization of E(m) and the decrease in R(i) induced by 6 mmol/L 1,8-cineole were unaltered by 200 micromol/L niflumic acid, a well known blocker of Ca(2+)-activated Cl(-) currents. 3. Significant correlations (Pearson correlation test) were found between changes in E(m) and decreases in AP amplitude (r = -0.893; P < 0.00282) and maximum ascendant inclination (r = -0.799; P < 0.0173), but not for maximum descendant inclination (r = 0.598; P < 0.117). Application of current to restore the transmembrane potential equal to control E(m) values in the presence of 6 mmol/L 1,8-cineole resulted in the partial recovery of AP. 4. The present study shows that 1,8-cineole effectively blocks the excitability of SCG neurons, probably through various mechanisms, one of which acts indirectly via depolarization of the neuronal cytoplasmatic membrane.

Inhibitory effect of 1,8-cineole on guinea-pig airway challenged with ovalbumin involves a preferential action on electromechanical coupling

1. 1,8-Cineole is a terpenoid constituent of essential oils with anti-inflammatory properties. It reduces the neural excitability, functions as an antinociceptive agent and has myorelaxant actions in guinea-pig airways. The aim of the present study was to investigate the mechanism underlying the myorelaxant effects of 1,8-cineole in guinea-pig isolated trachea from either naïve guinea-pigs or ovalbumin (OVA)-sensitized animals subjected to antigenic challenge. 2. Isometric recordings were made of the tone of isolated tracheal rings. Rings with an intact epithelium relaxed beyond basal tone in the presence of 1,8-cineole (6.5 x 10(-6) to 2 x 10(-2) mol/L) in a concentration-dependent manner (P < 0.001, anova) with a pD(2) value of 2.23 (95% confidence interval 2.10-2.37). Removal of the epithelium or pretreatment of intact tissue for 15 min with 50 micromol/L N(G)-nitro-l-arginine methyl ester, 5 mmol/L tetraethylammonium, 0.5 micromol/L tetrodotoxin or 5 micromol/L propranolol did not alter the potency (pD(2)) or the maximal myorelaxant effect (E(max)) of 1,8-cineole. 3. 1,8-Cineole also significantly decreased the Schultz-Dale contraction induced by OVA, mainly in preparations from OVA-sensitized animals submitted to antigen challenge. 1,8-Cineole decreased tracheal hyperresponsiveness to KCl and carbachol caused by antigen challenge and almost abolished the concentration-response curves to KCl, whereas it had little effect on the concentration-response curves to carbachol. Under Ca(2+)-free conditions and in the presence of 10(-4) mol/L acetylcholine, neither 1,8-cineole (6.5 x 10(-3) mol/L) nor verapamil (1 x 10(-5) mol/L) affected Ca(2+)-induced contractions, but they almost abolished Ba(2+)-induced contractions. 4. In conclusion, the findings of the present study show that 1,8-cineole is a tracheal myorelaxant that acts preferentially on contractile responses elicited electromechanically.

Complementary and alternative medicine: herbs, phytochemicals and vitamins and their immunologic effects

Complementary and alternative medicines (CAMs) are used in more than 80% of the world's population and are becoming an increasing component of the US health care system, with more than 70% of the population using CAM at least once and annual spending reaching as much as $34 billion. Since the inception of the National Center for Complementary and Alternative Medicine, there has been an enormous increase in the number of basic science and therapy-based clinical trials exploring CAM. The subspecialty of allergy and immunology represents a particularly fertile area with a large number of CAM therapies that have been shown to affect the immune system. Recent work has uncovered potential biochemical mechanisms involved in the immunomodulatory pathway of many supplemental vitamins (A, D, and E) that appear to affect the differentiation of CD4(+) cell T(H)1 and T(H)2 subsets. Other research has shown that herbs such as resveratrol, quercetin, and magnolol may affect transcription factors such as nuclear factor-kappaB and the signal transducer and activator of transcription/Janus kinase pathways with resultant changes in cytokines and inflammatory mediators. Clinically, there have been hundreds of trials looking at the effect of CAM on asthma, allergic rhinitis, and atopic dermatitis. This article reviews the history of CAM and its use among patients, paying special attention to new research focusing on herbals, phytochemicals, and vitamins and their potential interaction with the immune system.

Stimulatory effect of Eucalyptus essential oil on innate cell-mediated immune response

BACKGROUND

Besides few data concerning the antiseptic properties against a range of microbial agents and the anti-inflammatory potential both in vitro and in vivo, little is known about the influence of Eucalyptus oil (EO) extract on the monocytic/macrophagic system, one of the primary cellular effectors of the immune response against pathogen attacks. The activities of this natural extract have mainly been recognized through clinical experience, but there have been relatively little scientific studies on its biological actions. Here we investigated whether EO extract is able to affect the phagocytic ability of human monocyte derived macrophages (MDMs) in vitro and of rat peripheral blood monocytes/granulocytes in vivo in absence or in presence of immuno-suppression induced by the chemotherapeutic agent 5-fluorouracil (5-FU).

METHODS

Morphological activation of human MDMs was analysed by scanning electron microscopy. Phagocytic activity was tested: i) in vitro in EO treated and untreated MDMs, by confocal microscopy after fluorescent beads administration; ii) in vivo in monocytes/granulocytes from peripheral blood of immuno-competent or 5-FU immuno-suppressed rats, after EO oral administration, by flow cytometry using fluorescein-labelled E. coli. Cytokine release by MDMs was determined using the BD Cytometric Bead Array human Th1/Th2 cytokine kit.

RESULTS

EO is able to induce activation of MDMs, dramatically stimulating their phagocytic response. EO-stimulated internalization is coupled to low release of pro-inflammatory cytokines and requires integrity of the microtubule network, suggesting that EO may act by means of complement receptor-mediated phagocytosis. Implementation of innate cell-mediated immune response was also observed in vivo after EO administration, mainly involving the peripheral blood monocytes/granulocytes. The 5-FU/EO combined treatment inhibited the 5-FU induced myelotoxicity and raised the phagocytic activity of the granulocytic/monocytic system, significantly decreased by the chemotherapic.

CONCLUSION

Our data, demonstrating that Eucalyptus oil extract is able to implement the innate cell-mediated immune response, provide scientific support for an additional use of this plant extract, besides those concerning its antiseptic and anti-inflammatory properties and stimulate further investigations also using single components of this essential oil. This might drive development of a possible new family of immuno-regulatory agents, useful as adjuvant in immuno-suppressive pathologies, in infectious disease and after tumour chemotherapy.

Gas chromatography/mass spectrometry analysis of Laurus nobilis essential oil composition of northern Cyprus

The chemical composition of the essential oil isolated from the leaves of the Laurus nobilis plant (from the Northern Cyprus Mountains) by hydrodistillation was analyzed by gas chromatography-mass spectrometry. Of the 81 compounds representing 98.74% of total oil, monocyclic monoterpenes such as 1,8-cineole (58.59%), alpha-terpinyl acetate (8.82%), and terpinene-4-ol (4.25%) were the main components. Bicyclic monoterpenes such as alpha- and beta- pinene (3.39-3.25%) and sabinene (3.32%) were also identified. The acyclic monoterpenes linalool (0.19%) and myrcenol (0.10%) were present in smaller amounts, and so were the sesquiterpenes. o-Cymene (1.30%) and p-cymene (1.83%) were the main, while cumin aldehyde (0.24%), dimethylstyrene (0.08%), eugenol (0.16%), methyl eugenol (0.05%), and carvacrol (0.05%) were found as minor, aromatic compounds of laurel oil.

Herbal interventions for chronic asthma in adults and children

BACKGROUND

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

OBJECTIVES

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

SEARCH STRATEGY

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Herbal treatments of asthma: a systematic review

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Pharmacological and chemical effects of cigarette additives

We investigated tobacco industry documents and other sources for evidence of possible pharmacological and chemical effects of tobacco additives. Our findings indicated that more than 100 of 599 documented cigarette additives have pharmacological actions that camouflage the odor of environmental tobacco smoke emitted from cigarettes, enhance or maintain nicotine delivery, could increase the addictiveness of cigarettes, and mask symptoms and illnesses associated with smoking behaviors. Whether such uses were specifically intended for these agents is unknown. Our results provide a clear rationale for regulatory control of tobacco additives.

Smart textiles: a new drug delivery system for symptomatic treatment of a common cold

Smart textiles provide the possibility of being coated with cineole, menthol, and camphor. Due to over-the-counter availability, ethereal oils are frequently used to treat a common cold. The existing pharmaceutical forms entail the risk of oral ingestion by children, which can cause severe intoxications. This risk could be limited by a smart textile application. Prior to applicability tests in children, the principal traceability of smart textile-applied ethereal oils at their site of action in the alveoli has to be demonstrated. Therefore, a crossover trial (ointment vs smart textiles) with 6 healthy volunteers was carried out as a proof-of-concept study. As a result, the principle proof is given that smart textile-applied ethereal oils are available at their site of action. Because of the volatility of the active ingredients, a close-fitting textile form has to be developed for further clinical development of smart textiles to achieve higher concentrations in the alveoli. Slower liberation properties and a more convenient skin sensation in comparison to available pharmaceutical forms may provide advantages for the applicability in both children and adults.

Inhibitory effect of 1,8-cineol (eucalyptol) on Egr-1 expression in lipopolysaccharide-stimulated THP-1 cells

AIM

To study the effects of 1,8-cineol (eucalyptol) on the expression of early growth response factor-1 (Egr-1) and NF-kappaB in the human monocyte THP-1 cell line stimulated by lipopolysaccharide (LPS).

METHODS

The THP-1 cells were incubated with serial doses of 1,8-cineol (1, 10, and 100 mg/L, 30 min) before being stimulated with LPS (1 mg/L, 30 min). The localization of Egr-1 in the THP-1 cells was detected by immunofluorescence and a laser scanning confocal microscope. The expression of Egr-1 in the nuclei and whole cell, and NF-kappaB in the nuclei, were measured by Western blot analysis.

RESULTS

When stimulated by LPS, the FITC-labeled Egr-1 was detected mainly in the nuclei. Moreover, the expression of Egr-1 in the whole cell increased markedly compared with the control cells. 1,8-Cineol pretreatment decreased the expression of Egr-1 in both the nuclei and whole cell of the LPS-stimulated THP-1 cells, and this effect was concentration-dependent, but there was no reaction on the expression of NF-kappaB in the nuclei protein in the LPS-stimulated THP-1 cells.

CONCLUSION

In a concentration-dependent manner, 1,8-Cineol reduces LPS-induced Egr-1 expression in nuclei and in whole cell of THP-1 cells, but shows no effect on NF-kappaB expression.

Essential oil of croton nepetaefolius and its main constituent, 1,8-cineole, block excitability of rat sciatic nerve in vitro

1. The effects of the essential oil of Croton nepetaefolius (EOCN) and its major constituent, 1,8-cineole, on the compound action potential (CAP) of nerve were investigated. 2. Experiments were performed in sciatic nerves dissected from Wistar rats, mounted in a moist chamber and stimulated at a frequency of 0.2 Hz, with electric pulses of 100 micros duration at 20-40 V. Evoked CAP were displayed on an oscilloscope and recorded on a computer. The CAP control parameters were as follows: peak-to-peak amplitude 8.1 +/- 0.6 mV (n = 15); conduction velocity 83.3 +/- 4.2 m/s (n = 15); chronaxie 58.0 +/- 6.8 msec (n = 6); and rheobase 2.8 +/- 0.1 V (n = 6). 3. Lower concentrations of EOCN (100 and 300 microg/mL) and 1,8-cineole (153 and 307 microg/mL; i.e. 1 and 2 mmol/L, respectively) had no significant effects on CAP control parameters throughout the entire recording period. However, at the end of 180 min exposure of the nerve to the drug, peak-to-peak amplitude was significantly (P < 0.05) reduced to 27.4 +/- 6.7 and 1.7 +/- 0.8% of control values by 500 and 1000 microg/mL EOCN, respectively (n = 6), and to 76.5 +/- 4.4, 70.0 +/- 3.9 and 14.8 +/- 4.1% of control values by 614, 920 and 1227 microg/mL (i.e. 4, 6 and 8 mmol/L) 1,8-cineole, respectively (n = 6). Regarding conduction velocity, at the end of the 180 min exposure period, this parameter was significantly reduced to 85.8 +/- 7.3 and 48.7 +/- 12.3% (n = 6) of control values by 500 and 1000 microg/mL EOCN, respectively, and to 86.4 +/- 4.5 and 76.1 +/- 5.2% (n = 6) by 920 and 1227 microg/mL 1,8-cineole, respectively. Chronaxie and rheobase were significantly increased by the higher concentrations of both EOCN and 1,8-cineole. 4. It is concluded that EOCN and its main constituent 1,8-cineole block nerve excitability in a concentration-dependent manner, an effect that was totally reversible with 1,8-cineole but not with EOCN. This suggests that other constituents of EOCN, in addition to 1,8-cineole, may contribute to the mediation of this effect of EOCN.

Gas chromatography-mass spectrometry following pressurized hot water extraction and solid-phase microextraction for quantification of eucalyptol, camphor, and borneol inChrysanthemum flowers

Chrysanthemum flower is a common traditional Chinese medicine (TCM). In this work, pressurized hot water extraction (PHWE) followed by headspace solid-phase microextraction (HS-SPME) and GC-MS was developed for the determination of three main active volatile compounds of eucalyptol, camphor, and borneol in Chrysanthemum flowers from four different growing areas in China by internal standard method. The parameters of PHWE and HS-SPME were optimized. The method was also validated. The results showed that PHWE-SPME-GC-MS is a simple, rapid, efficient, and solvent-free technique for the quantitative determination of eucalyptol, camphor, and borneol in TCMs and is potentially useful for the TCM quality assessment.

Bronchitis, Bronchiolitis und Lungenemphysem

Die Bronchitis wird in die akute und die chronische Erkrankungsform eingeteilt. Bei der chronischen Form müssen zusätzlich das Vorhandensein einer zusätzlichen Atemwegsobstruktion und Sekundärveränderungen, insbesondere das Lungenemphysem, berücksichtigt werden.

A review of the bioactivity and potential health benefits of peppermint tea (Mentha piperita L.)

Peppermint (Mentha piperita L.) is one of the most widely consumed single ingredient herbal teas, or tisanes. Peppermint tea, brewed from the plant leaves, and the essential oil of peppermint are used in traditional medicines. Evidence-based research regarding the bioactivity of this herb is reviewed. The phenolic constituents of the leaves include rosmarinic acid and several flavonoids, primarily eriocitrin, luteolin and hesperidin. The main volatile components of the essential oil are menthol and menthone. In vitro, peppermint has significant antimicrobial and antiviral activities, strong antioxidant and antitumor actions, and some antiallergenic potential. Animal model studies demonstrate a relaxation effect on gastrointestinal (GI) tissue, analgesic and anesthetic effects in the central and peripheral nervous system, immunomodulating actions and chemopreventive potential. Human studies on the GI, respiratory tract and analgesic effects of peppermint oil and its constituents have been reported. Several clinical trials examining the effects of peppermint oil on irritable bowel syndrome (IBS) symptoms have been conducted. However, human studies of peppermint leaf are limited and clinical trials of peppermint tea are absent. Adverse reactions to peppermint tea have not been reported, although caution has been urged for peppermint oil therapy in patients with GI reflux, hiatal hernia or kidney stones.

Development of microwave-assisted extraction followed by headspace solid-phase microextraction and gas chromatography–mass spectrometry for quantification of camphor and borneol in Flos Chrysanthemi Indici

In the work, microwave-assisted extraction (MAE) followed by headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) was developed for quantitative analysis of the bioactive components of camphor and borneol in a traditional Chinese medicines (TCM) of Flos Chrysanthemi Indici. After systematical investigation, the optimal experimental parameters microwave power (400 W), irradiation time (4min), fiber coating (PDMS/DVB fiber), extraction temperature (40 degrees C), extraction time (20 min), stirring rate (1100 rpm), and salt effect (no salt added) were investigated. The optimized method provided satisfactory precision (RSD values less than 12%), good recovery (from 86% to 94%), and good linearity (R2>0.999). The proposed method was applied to quantitative analysis of camphor and borneol in Flos Chrysanthemi Indici samples from 11 different growing areas. To demonstrate the method feasibility, steam distillation was also used to analyze camphor and borneol in Flos Chrysanthemi Indici samples from these different growing areas. The very close results were obtained by the two methods. It has been shown that the proposed ME-HS-SPME-GC-MS is a simple, rapid, solvent-free and reliable method for quantitative analysis of camphor and borneol in TCM, and a potential tool for quality assessment of Flos Chrysanthemi Indici.

Plant active components - a resource for antiparasitic agents?

Plant essential oils (and/or active components) can be used as alternatives or adjuncts to current antiparasitic therapies. Garlic oil has broad-spectrum activity against Trypanosoma, Plasmodium, Giardia and Leishmania, and Cochlospermum planchonii and Croton cajucara oils specifically inhibit Plasmodium falciparum and Leishmania amazonensis, respectively. Some plant oils have immunomodulatory effects that could modify host-parasite immunobiology, and the lipid solubility of plant oils might offer alternative, transcutaneous delivery routes. The emergence of parasites resistant to current chemotherapies highlights the importance of plant essential oils as novel antiparasitic agents.

Therapeutic approaches to mucus hypersecretion

Mucolytic and related agents have been in use since prehistoric times. Although widely prescribed and used extensively in over-the-counter preparations, their efficacy and mechanisms of action remain in doubt. These agents belong to several distinct chemical classes. Mucolytic agents such as N-acetyl-cysteine are thiols with a free-sulfhydryl group. They are assumed to break disulfide bonds between gel-forming mucins and thus reduce mucus viscosity. Mucokinetic agents are thiols with a blocked sulfhydryl group. Expectorants such as guaifenesin increase mucus secretion. They may act as irritants to gastric vagal receptors, and recruit efferent parasympathetic reflexes that cause glandular exocytosis of a less viscous mucus mixture. Cough may be provoked. This combination may flush tenacious, congealed mucopurulent material from obstructed small airways and lead to a temporary improvement in dyspnea or the work of breathing. The roles of anticholinergic agents, DNase, and other drugs are also discussed with regard to their roles in reducing mucus production in rhinitis and other airway diseases.

Natural ozone scavenger prevents asthma in sensitized rats

The assumption that ozone is not only a strong oxidant, but also an important inflammatory mediator, is heavily supported by the ample literature on the pulmonary toxicity and biological effects of environmental ozone and by the recent discovery that antibodies, human neutrophils, and inflammatory lesions catalyze the formation of ozone in vivo. We hypothesized that the pulmonary inflammation in asthma involves a vicious circle of ozone production and recruitment of white blood cells, which produce more ozone. Accordingly, we predicted that electron-rich olefins, which are known ozone scavengers, could be used for prophylactic treatment of asthma. In particular, volatile, unsaturated monoterpenes, could saturate the pulmonary membranes and thereby equip the airways with local chemical protection against either exogenous or endogenous ozone. Here we present experimental evidence using a sensitized rat model to support this hypothesis. Examination of the pulmonary function of sensitized rats that inhaled either limonene (unsaturated, ozone scavenger) or eucalyptol (saturated, inert to ozone) showed that limonene inhalation significantly prevents bronchial obstruction while eucalyptol inhalation does not cause any effect. The anti-inflammatory effect of limonene was also evident from pathological parameters, such as diminished peribronchiolar and perivascular inflammatory infiltrates.

Inhibitory activity of 1,8-cineol (eucalyptol) on cytokine production in cultured human lymphocytes and monocytes

BACKGROUND

The therapeutic value of secretolytic agents in COPD and asthma is still disputed. For this reason, in a preclinical study we aimed to test the potential anti-inflammatory efficacy of 1,8-cineol (eucalyptol) in inhibiting polyclonal stimulated cytokine production by human unselected lymphocytes and LPS-stimulated monocytes.

METHODS

Cytokine production was determined following 20 h of incubation cells with 1,8-cineol simultaneously with the stimuli in culture supernatants by enzyme immunoassay.

RESULTS

Therapeutic concentrations of 1,8-cineol (1.5 microg/ml=10(-5)M) inhibited significantly (n=13-19, p=0.0001) cytokine production in lymphocytes of TNF-alpha > IL-1beta> IL-4> IL-5 by 92, 84, 70, and 65%, respectively. Cytokine production in monocytes of TNF-alpha > IL-1beta> IL-6> IL-8 was also significantly (n=7-16, p<0.001) inhibited by 99, 84, 76, and 65%, respectively. In the presence of 1,8-cineol (0.15 microg/ml=10(-6)M) production of TNF-alpha>IL-1beta by monocytes and of IL-1beta> TNF-alpha by lymph-ocytes was significantly inhibited by 77, 61 and by 36, 16%, respectively. 1,8-cineol (10(-6)M) had a larger impact on TNF-alpha and IL-1beta-production in monocytes compared to lymphocytes (p<0.03) and similar effects (p>0.59) at therapeutically relevant concentrations of 1,8-Cineol (10(-5)M).

CONCLUSION

These results characterize 1,8-cineol as strong inhibitor of TNF-alpha and IL-1beta and suggest smaller effects on chemotactic cytokines. This is increasing evidence for the role of 1,8-cineol to control airway mucus hypersecretion by cytokine inhibition, suggesting long-term treatment to reduce exacerbations in asthma, sinusitis and COPD.

Pretreatment with 1,8-cineole potentiates thioacetamide-induced hepatotoxicity and immunosuppression

The effect of 1,8-cineole on cytochrome P450 (CYP) expression was investigated in male Sprague Dawley rats and female BALB/c mice. When rats were treated orally with 200, 400 and 800 mg/kg of 1,8-cineole for 3 consecutive days, the liver microsomal activities of benzyloxyresorufin- and pentoxyresorufin-omicron-dealkylases and erythromycin N-demethylase were dose-dependently induced. The Western immunoblotting analyses clearly indicated the induction of CYP 2B1/2 and CYP 3A1/2 proteins by 1,8-cineole. At the doses employed, 1,8-cineole did not cause toxicity, including hepatotoxicity. Subsequently, 1,8-cineole was applied to study the role of metabolic activation in thioacetamide-induced hepatotoxicity and/or immunotoxicity in animal models. To investigate a possible role of metabolic activation by CYP enzymes in thioacetamide-induced hepatotoxicity, rats were pre-treated with 800 mg/kg of 1 ,8-cineole for 3 days, followed by a single intraperitoneal treatment with 50 and 100 mg/kg of thioacetamide in saline. 24 h later, thioacetamide-induced hepatotoxicity was significantly potentiated by the pretreatment with 1,8-cineole. When female BALB/c mice were pretreated with 800 mg/kg of 1,8-cineole for 3 days, followed by a single intraperitoneal treatment with 100 mg/kg of thioacetamide, the antibody response to sheep red blood cells was significantly potentiated. In addition, the liver microsomal activities of CYP 2B enzymes were significantly induced by 1,8-cineole as in rats. Taken together, our results indicated that 1,8-cineole might be a useful CYP modulator in investigating the possible role of metabolic activation in chemical-induced hepatotoxicity and immunotoxicity.

Complementary and alternative medicine for bronchial asthma: is there new evidence?

PURPOSE OF REVIEW

Complementary and alternative medicine is widely used in bronchial asthma. Data on efficacy of these treatment modalities are lacking.

RECENT FINDINGS

Studies published since June 2002 on complementary and alternative medicine in bronchial asthma were systematically reviewed.

SUMMARY

Studies do not support the use of homeopathy, air ionizers, manual therapy, or acupuncture for asthma. These methods bear some risks to patients related to undertreatment and side effects. There might be a possible, but so far not clearly established, role for antioxidant dietary supplementation, and some natural antiinflammatory and immunomodulatory remedies. However, their effect size compared with the classical treatment and side-effect profile is not clearly established. Strategies influencing breathing technique or perception, such as breathing or retraining exercises, need to be studied over the next few years to establish their additive role in the treatment of asthma. Breathing exercises could improve lung function and quality of life in different studies. Psychotherapy-related methods such as relaxation, hypnosis, autogenic training, speleotherapy, and biofeedback might have a small effect in selected cases, but have not proven to be superior to placebo. Nevertheless, more randomized controlled trials of good methodological quality are required to allow firm conclusions.