Treatment of the common cold with echinacea: a structured review.
(17/92)
BACKGROUND: Echinacea is a herbal preparation that is frequently used to treat the common cold. Spending on echinacea in the United States has risen to >300 million dollars annually. METHODS: A total of 322 articles related to echinacea and colds, including 9 placebo-controlled clinical trials, were identified using the Medline and PubMed databases. Eleven features of experimental design that affect the accuracy of the measurement of features of interest, the probability of a chance relationship, bias, and blinding were used to evaluate the 9 placebo-controlled studies. The criteria were validated case definition, quantifiable hypothesis, sample-size calculation, randomized assignment, double blinding, proof of blinding, measurement of compliance, measurement of drop-out rate, analysis by intention to treat, description of the methods of analysis, and measurement of probability. Equal weight was given to each criterion, since failure to meet any one of them could potentially invalidate the findings of a clinical trial. RESULTS: Of the 9 studies, 2 met all 11 criteria. The results of both studies were judged to be negative by the people who performed the studies. Of the remaining 7 studies, 6 were judged to have positive results, and 1 was judged to have negative results. The criterion most commonly not met was proof of blinding. CONCLUSIONS: This structured review suggests that the possible therapeutic effectiveness of echinacea in the treatment of colds has not been established. (+info)
Optimization of "Askoeziuofito" tablets.
(18/92)
OBJECTIVE: To determine experimentally the optimal limits of excipients (silica colloidal anhydrous, magnesium stearate, potato starch, saccharose), which would determine the following technological properties of the tablets: sticking of the mass to the puansons, crushing strength, resistance to abrasion-off and the speed at which medicinal substances are released from the tablets. MATERIAL AND METHODS: The following technological parameters were assessed according to the requirements of European Pharmacopoeia 04/2002:0479: mean mass, crushing strength, resistance to abrasion, duration of decomposition, speed of release of ascorbic and chicoric acids. Ferments and ascorbic acid were identified by color and precipitation reactions. Flavonoids (quercetin, quercitrin, kempferol, hyperoside, vitexin, luteolin) were identified by method of high-pressure liquid chromatography; caffeic and ascorbic acids were identified by method of thin layer chromatography; and hydroxycinnamonic acids -- by method of spectrophotometry. In tablets, ascorbic acid was quantitatively determined using the method of oxidimetry, and chicoric acid -- using the method of spectrophotometry. It has been established that the use of techniques of mathematical planning (2(4-1) fraction replica plan, maximum gradient direction and orthogonal compositional plan) made it possible to select optimal amounts of excipients which determine optimal quality requirements for production of tablets: crushing strength, resistance to abrasion, pressing, disintegration time and release rate of medicinal substances. By applying chemical and physico-chemical methods of analysis in determining active substances in tablets, technology for analyzing such preparations has been developed and stability tests have been performed. (+info)
Genetic variation in Echinacea angustifolia along a climatic gradient.
(19/92)
BACKGROUNDS AND AIMS: Echinacea angustifolia is a widespread species distributed throughout the Great Plains region of North America. Genetic differentiation among populations was investigated along a 1500 km north-south climatic gradient in North America, a region with no major geographical barriers. The objective of the study was to determine if genetic differentiation of populations could be explained by an isolation-by-distance model or by associations with climatic parameters known to affect plant growth and survival. METHODS: Historical climatic data were used to define the nature of the climatic gradient and AFLP markers were used to establish patterns of population genetic differentiation among ten Echinacea populations collected from North Dakota to Oklahoma. A total of 1290 fragments were scored using six EcoRI/MseI and three PstI/MseI primer combinations. Assessment of the correlation between climatic, genetic and geographic distances was assessed by Mantel and partial Mantel tests. KEY RESULTS: PstI/MseI combinations produced significantly fewer fragments, but a larger percentage was unique compared with EcoRI/MseI markers. Using estimates of F(ST), populations in Oklahoma and southern Kansas were identified as the most divergent from the other populations. Both the neighbour-joining tree and principal co-ordinate analysis clustered the populations in a north-south spatial orientation. About 60% of the genetic variation was found within populations, 20% among populations and the remaining 20% was partitioned among groups that were defined by the topology of the neighbour-joining tree. Significant support was found for the isolation-by-distance model independent of the effects of annual mean precipitation, but not from annual mean temperature and freeze-free days. CONCLUSIONS: Echinacea angustifolia populations exhibit genetic divergence along a north-south climatic gradient. The data support an isolation-by-distance restriction in gene flow that is independent of annual mean precipitation. (+info)
An evaluation of Echinacea angustifolia in experimental rhinovirus infections.
(20/92)
BACKGROUND: Echinacea has been widely used as an herbal remedy for the common cold, but efficacy studies have produced conflicting results, and there are a variety of echinacea products on the market with different phytochemical compositions. We evaluated the effect of chemically defined extracts from Echinacea angustifolia roots on rhinovirus infection. METHODS: Three preparations of echinacea, with distinct phytochemical profiles, were produced by extraction from E. angustifolia roots with supercritical carbon dioxide, 60 percent ethanol, or 20 percent ethanol. A total of 437 volunteers were randomly assigned to receive either prophylaxis (beginning seven days before the virus challenge) or treatment (beginning at the time of the challenge) either with one of these preparations or with placebo. The results for 399 volunteers who were challenged with rhinovirus type 39 and observed in a sequestered setting for five days were included in the data analysis. RESULTS: There were no statistically significant effects of the three echinacea extracts on rates of infection or severity of symptoms. Similarly, there were no significant effects of treatment on the volume of nasal secretions, on polymorphonuclear leukocyte or interleukin-8 concentrations in nasal-lavage specimens, or on quantitative-virus titer. CONCLUSIONS: The results of this study indicate that extracts of E. angustifolia root, either alone or in combination, do not have clinically significant effects on infection with a rhinovirus or on the clinical illness that results from it. (+info)
Non-antibiotic treatments for upper-respiratory tract infections (common cold).
(21/92)
OBJECTIVES: To review the seven Cochrane reviews of non-antibiotic treatment for the common cold. METHODS: Each Cochrane review was read and summarized, and results presented as relative risks and, where possible, numbers needed to treat. RESULTS: The main theme that runs through these Cochrane reviews is the variable quality of the primary studies. In general, the reviewers are fairly cautious about the benefits of any of the treatments other than first-dose decongestants and antihistamine-decongestant combinations. For antihistamines alone, the reviewers were clear about the lack of efficacy except in the high-quality studies in which a global improvement in symptoms was noted. Some studies were statistically significant, but the Cochrane reviewers were guarded about how clinically significant they were. For Echinacea, problems were found with the quality of the studies and the wide range of different forms of this substance. Heated humidified air seemed to be effective in the UK and Israel, but not the USA, making definitive statements about efficacy difficult. Over-the-counter medication for cough seemed to have no documented benefit in children under the age of 5 years. Letosteine (a mucolytic) may be effective in children but is not available in the UK. Bisolvon (a mucolytic) was found to be effective for cough in only one study. For older children and adults, dextromethorphan may be effective (two out of three studies showed benefit), and guiafenesin (an expectorant) showed mixed benefit in two trials. Dexbrompheniramine (a sedating antihistamine)/pseudoephedrine (6 mg/120 mg twice daily for 1 week) was significantly more effective than placebo for severity of cough, whereas, in another study, loratadine (a non-sedating antihistamine)/pseudoephedrine (5 mg/120 mg twice daily for 4 days) did not show any difference between the study groups. Vitamin C may have a small role in preventing the common cold, with possibly a greater role in high-intensity physical activity and sub-arctic conditions. Zinc lozenges seemed to be effective, but the issue of unblinding due to taste was a methodological issue of concern to the reviewers. The benefits and harms are calculated as numbers needed to treat for one person to benefit (NNTB) and numbers needed to treat for one person to harm (NNTH), and were calculated by the author. CONCLUSION: Most non-antibiotic treatments for the common cold are probably not effective. The most promising are dextromethorphan, bisolvon and guiaphenesin for cough, antihistamine-decongestant combinations for a wide range of symptoms, nasal decongestants (at least for the first dose) and possibly zinc lozenges. (+info)
Floral nectar production and nectary anatomy and ultrastructure of Echinacea purpurea (Asteraceae).
(22/92)
BACKGROUND AND AIMS: In spite of the impressive species diversity in the Asteraceae and their widespread appeal to many generalist pollinators, floral-nectary ultrastructure in the family has rarely been investigated. To redress this, a study using Echinacea purpurea, a plant of horticultural and nutraceutical value, was undertaken. Nectar secretion of disc florets was compared with floral nectary ultrastructure taking into account nectar's potential impact upon the reproductive success of this outcrossing species. METHODS: Micropipette collections of nectar in conjunction with refractometry were used to determine the volume and nectar-sugar quantities of disc florets throughout their phenology, from commencement of its production to cessation of secretion. Light, scanning-electron and transmission-electron microscopy were utilized to examine morphology, anatomy and ultrastructure of nectaries of the disc florets. KEY RESULTS: Florets were protandrous with nectar being secreted from anthesis until the third day of the pistillate phase. Nectar production per floret peaked on the first day of stigma receptivity, making the two innermost whorls of open florets most attractive to foraging visitors. Modified stomata were situated along the apical rim of the collar-like nectary, which surrounds the style base and sits on top of the inferior ovary. The floral nectary was supplied by phloem only, and both sieve elements and companion cells were found adjacent to the epidermis; the latter participated in the origin of some of the precursor cells that yielded these specialized cells of phloem. Companion cells possessed wall ingrowths (transfer cells). Lobed nuclei were a key feature of secretory parenchyma cells. CONCLUSIONS: The abundance of mitochondria suggests an eccrine mechanism of secretion, although dictyosomal vesicles may contribute to a granulocrine process. Phloem sap evidently is the main contributor of nectar carbohydrates. From the sieve elements and companion cells, an apoplastic route via intercellular spaces and cell walls, leading to the pores of modified stomata, is available. A symplastic pathway, via plasmodesmata connecting sieve elements to companion, parenchyma and epidermal cells, is also feasible. Uncollected nectar was reabsorbed, and the direct innervation of the nectary by sieve tubes potentially serves a second important route for nectar-sugar reclamation. Microchannels in the outer cuticle may facilitate both secretion and reabsorption. (+info)
Alkylamides from Echinacea are a new class of cannabinomimetics. Cannabinoid type 2 receptor-dependent and -independent immunomodulatory effects.
(23/92)
Alkylamides (alkamides) from Echinacea modulate tumor necrosis factor alpha mRNA expression in human monocytes/macrophages via the cannabinoid type 2 (CB2) receptor (Gertsch, J., Schoop, R., Kuenzle, U., and Suter, A. (2004) FEBS Lett. 577, 563-569). Here we show that the alkylamides dodeca-2E,4E,8Z,10Z-tetraenoic acid isobutylamide (A1) and dodeca-2E,4E-dienoic acid isobutylamide (A2) bind to the CB2 receptor more strongly than the endogenous cannabinoids. The Ki values of A1 and A2 (CB2 approximately 60 nM; CB1 >1500 nM) were determined by displacement of the synthetic high affinity cannabinoid ligand [3H]CP-55,940. Molecular modeling suggests that alkylamides bind in the solvent-accessible cavity in CB2, directed by H-bonding and pi-pi interactions. In a screen with 49 other pharmacologically relevant receptors, it could be shown that A1 and A2 specifically bind to CB2 and CB1. A1 and A2 elevated total intracellular Ca2+ in CB2-positive but not in CB2-negative promyelocytic HL60 cells, an effect that was inhibited by the CB2 antagonist SR144528. At 50 nM, A1, A2, and the endogenous cannabinoid anandamide (CB2 Ki >200 nM) up-regulated constitutive interleukin (IL)-6 expression in human whole blood in a seemingly CB2-dependent manner. A1, A2, anandamide, the CB2 antagonist SR144528 (Ki <10 nM), and also the non-CB2-binding alkylamide undeca-2E-ene,8,10-diynoic acid isobutylamide all significantly inhibited lipopolysaccharide-induced tumor necrosis factor alpha, IL-1beta, and IL-12p70 expression (5-500 nM) in a CB2-independent manner. Alkylamides and anandamide also showed weak differential effects on anti-CD3-versus anti-CD28-stimulated cytokine expression in human whole blood. Overall, alkylamides, anandamide, and SR144528 potently inhibited lipopolysaccharide-induced inflammation in human whole blood and exerted modulatory effects on cytokine expression, but these effects are not exclusively related to CB2 binding. (+info)
Relations among questionnaire and laboratory measures of rhinovirus infection.
(24/92)
Due to high incidence and quality-of-life impact, upper respiratory infection substantially impacts on population health. To test or compare treatment effectiveness, a well-designed and validated illness-specific quality-of-life instrument is needed. Data reported in the current study were obtained from a trial testing echinacea for induced rhinovirus infection. Laboratory-assessed biomarkers included interleukin (IL)-8, nasal neutrophil count (polymorphonuclear neutrophils (PMN)), mucus weight, viral titre and seroconversion. The questionnaires used included the general health short form (SF)-8 (24-h recall version), the eight-item Jackson cold scale, and the 44-item Wisconsin Upper Respiratory Symptom Survey (WURSS). In total, 399 participants were inoculated with rhinovirus and monitored over 2,088 person-days. Statistically significant associations were found among nearly all variables. Between-questionnaire correlations were: WURSS-Jackson = 0.81; WURSS-SF-8 = 0.62; and Jackson-SF-8 = 0.60. Correlations with laboratory values were as follows: WURSS-mucus weight = 0.53; Jackson-mucus weight = 0.55; WURSS-viral titre = 0.37; Jackson-viral titre = 0.46; WURSS-IL-8 = 0.31; Jackson-IL-8 = 0.36; WURSS-PMN = 0.31; and Jackson-PMN = 0.28. Neither WURSS nor Jackson yielded satisfactory cut-off scores for diagnosis of infection. Symptomatic and biological outcomes of upper respiratory infection are highly variable, with only modest associations. While Wisconsin Upper Respiratory Symptom Survey and Jackson questionnaires both correlate with biomarkers, neither is a good predictor of induced infection. The inclusion of functional and quality-of-life items in the Wisconsin Upper Respiratory Symptom Survey does not significantly decrease the strength of association with laboratory-assessed biomarkers. (+info)