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At least 19 recordsLinked to original sources
PubMed2002

Simultaneous analysis of alkamides and caffeic acid derivatives for the identification of Echinacea purpurea, Echinacea angustifolia, Echinacea pallida and Parthenium integrifolium roots.

A reversed-phase HPLC method was developed using a computer simulation program for the identification of dried roots of Echinacea purpurea, E. angustifolia, E. pallida and Parthenium integrifolium. Hydrophilic and lipophilic compounds were analysed simultaneously leading to a two-fold decrease in analysis time compared to traditional HPLC methods.

Asteraceae↗
PubMed2004

The effect of echinacea (Echinacea purpurea root) on cytochrome P450 activity in vivo.

BACKGROUND: Echinacea is a widely available over-the-counter herbal remedy. Tinctures of echinacea have been shown to inhibit cytochrome P450 (CYP) in vitro. The effect of echinacea (Echinacea purpurea root) on CYP activity in vivo was assessed by use of the CYP probe drugs caffeine (CYP1A2), tolbutamide (CYP2C9), dextromethorphan (CYP2D6), and midazolam (hepatic and intestinal CYP3A). METHODS: Twelve healthy subjects (6 men) completed this 2-period, open-label, fixed-schedule study. Caffeine, tolbutamide, dextromethorphan, and oral and intravenous midazolam were administered before and after a short course of echinacea (400 mg 4 times a day for 8 days) to determine in vivo CYP activities. RESULTS: Echinacea administration significantly increased the systemic clearance of midazolam by 34%, from 32 +/- 7 L/h to 43 +/- 16 L/h (P =.003; 90% confidence interval [CI], 116%-150%), and significantly reduced the midazolam area under the concentration-time curve by 23%, from 127 +/- 36 microg. h/L to 102 +/- 43 microg. h/L (P =.024; 90% CI, 63%-88%). In contrast, the oral clearance of midazolam was not significantly altered (P =.655; 90% CI, 75%-124%), 137 +/- 19 L/h compared with 146 +/- 71 L/h. The oral availability of midazolam after echinacea dosing was significantly increased (P =.028; 90% CI, 108%-153%), from 0.23 +/- 0.06 to 0.33 +/- 0.13. Hepatic availability (0.72 +/- 0.08 versus 0.61 +/- 0.16; P =.006; 90% CI, 73%-90%) and intestinal availability (0.33 +/- 0.11 versus 0.61 +/- 0.38; P =.015; 90% CI, 125%-203%) were significantly altered in opposite directions. Echinacea dosing significantly reduced the oral clearance of caffeine, from 6.6 +/- 3.8 L/h to 4.9 +/- 2.3 L/h (P =.049; 90% CI, 58%-96%). The oral clearance of tolbutamide was reduced by 11%, from 0.81 +/- 0.18 L/h to 0.72 +/- 0.19 L/h, but this change was not considered to be clinically relevant because the 90% CIs were within the 80% to 125% range. The oral clearance of dextromethorphan in 11 CYP2D6 extensive metabolizers was not affected by echinacea dosing (1289 +/- 414 L/h compared with 1281 +/- 483 L/h; P =.732; 90% CI, 89%-108%). CONCLUSIONS: Echinacea (E purpurea root) reduced the oral clearance of substrates of CYP1A2 but not the oral clearance of substrates of CYP2C9 and CYP2D6. Echinacea selectively modulates the catalytic activity of CYP3A at hepatic and intestinal sites. The type of drug interaction observed between echinacea and other CYP3A substrates will be dependent on the relative extraction of drugs at hepatic and intestinal sites. Caution should be used when echinacea is coadministered with drugs dependent on CYP3A or CYP1A2 for their elimination.

Administration, Oral↗
PubMed2002

Immunological and haematinic consequences of feeding a standardised Echinacea (Echinacea angustifolia) extract to healthy horses.

This study was undertaken to compile new data on the efficacy of Echinacea in stimulating the immune system of the horse. Use of Echinacea is becoming widespread in horses, despite an absence of controlled laboratory research into its effectiveness or safety. This paper documents results of a double-blind, placebo-controlled, cross-over trial investigating the effect of standardised Echinacea extract on 8 horses. Animals were supplemented with Echinacea or placebo for 42 days, and their response to supplements recorded. Treatment with Echinacea increased phagocytic ability of isolated neutrophils, boosted peripheral lymphocyte counts and appeared to stimulate neutrophil migration from peripheral circulation into the tissues. Echinacea supplement also increased the size and concentration of peripheral red blood cells, and the concentration of haemoglobin and packed cell volume. It was concluded that Echinacea effectively stimulates equine immunocompetence, and the plant extract behaves, in equine subjects, as a haematinic agent, i.e. one which improves the quality of blood by increasing haemoglobin levels and the number of erythrocytes and which, by virtue of their effects on oxygen transport cells, are considered to improve parameters of exercise physiology and performance.

Adjuvants, Immunologic↗
PubMed2003

Effect of Echinacea (Echinacea Purpurea L. Moench) preparations on experimental prostate gland.

This work has investigated the effect of echinacea extract on the weight of prostates in rats as well as on alterations of hystological structure and separate blood cells. This preparation was chosen for investigations due to its possible antiandrogenic effect and good immunostimulating features. Experiments were carried out with three-month old male Wistar rats, divided by six into three different groups. The first group was the control one. The rats of the second group were fed for 30 days with the usual food ration plus 50 mg/kg of echinacea extract. The third group was fed for 60 days in the same way as the second one. Clinical death of rats was caused by sodium phenobarbital, later a cervical dislocation was performed. After weighing the rats their prostates were removed and weighed. Patohystological investigations of the removed organs were carried out. Blood test for Shiling's analysis was taken. The weight of prostates in the first group of rats was 412.0+/-14.93 mg, in the second group - 403.0+/-13.33 mg, and in the third group it was 388.0+/-14.66 mg. Having calculated the proportion between prostates of rats and their body weight it was estimated that in the first group it made 0.125+/-0.009%, in the second group - 0.105+/-0.005%, and in the third group - 0.091+/-0.007%. The percentage of lymphocytes in the first group was 72+/-1.41; in the second group - 73+/-0.81; in the third group - 79+/-1,86. The percentage of segmented neutrophyle in the first group was 23+/-3.31; in the second group - 23+/-2.25; in the third group - 18+/-2.33. Having conducted analysis of the experimental results, a significantly important decrease of prostate weight of investigated rats, an increase in the number of lymphocyte as well as the alterations of hystological structures after using echinacea extract for eight weeks were observed.

Androgen Antagonists↗
PubMed1996

[Clinical application of extracts of Echinacea purpurea or Echinacea pallida. Critical evaluation of controlled clinical studies].

The phytotherapy should be understood as being integrated into the rational pharmacotherapy. The modern phytotherapy tries hard to proof effects with pharmacological and clinical studies. The task force E of the federal bureau of health of Germany has made a statement regarding this problem. This article reviews only controlled clinical trials about the application of extracts of echinacea purpura or echinacea pallida.

Adjuvants, Immunologic↗
PubMed1999

Effects of an orally applied aqueous-ethanolic extract of a mixture of Thujae occidentalis herba, Baptisiae tinctoriae radix, Echinaceae purpureae radix and Echinaceae pallidae radix on antibody response against sheep red blood cells in mice.

The influence of the oral administration of an aqueous-ethanolic extract of a mixture of Thujae occidentalis herba, Baptisiae tinctoriae radix, Echinaceae purpureae radix and Echinaceae pallidae radix, on the immune response in mice was investigated. The data show that the extract significantly enhances the antibody response to sheep red blood cells (SRBC), induces an increase in the numbers of splenic plaque forming cells (PFC) and an increase in the titer of specific antibodies in the sera of treated animals. The long-term application of the extract over several months also stimulated the PFC-response without affecting spleen weight, total cell yield per spleen or white blood cell count in mice.

Administration, Oral↗
PubMed1993

[Immunomodulating activity of ethanol-water extracts of the roots of Echinacea gloriosa L., Echinacea angustifolia DC. and Rudbeckia speciosa Wenderoth tested on the immune system in C57BL6 inbred mice].

The ethanolic extract from the roots Echinacea gloriosa L. (Moench), Echinacea angustifolia DC. and Rudbeckia speciosa Wenderoth shows immunomodulating activity. It was seen on the seventh day after five days of in vivo treatment of mice. The most marked immunostimulatory effect was observed on the lysosomal and peroxidal activity of peritoneal macrophages, and splenic cells after in vivo treatment with the ethanolic extract of the roots of R. speciosa Wenderoth.

Adjuvants, Immunologic↗
PubMed2002

Adverse reactions associated with echinacea: the Australian experience.

BACKGROUND: Fifty percent of Australians use complementary and alternative medicines (other than vitamins) in any 12-month period, of which echinacea-containing products are increasingly popular. Recent reports have highlighted the risk of allergic reactions to complementary medicines in atopic patients. OBJECTIVE: To determine the characteristics of adverse reactions linked to use of the popular herbal remedy echinacea. METHODS: Five privately referred patients were evaluated by the authors in their office practice via skin prick testing (SPT) on the volar aspect of the forearm and radioallergosorbent test after adverse reactions to echinacea. As there was little published information on adverse reactions to echinacea, reports to the Australian Adverse Drug Reactions Advisory Committee were reviewed. Those suggestive of possible allergic reactions were evaluated in greater detail by anonymously surveying the healthcare professionals who had reported the cases and from one unreported case. Serum was collected for further analysis where possible. RESULTS: Five cases of adverse reactions to echinacea were personally evaluated by the authors. Two patients suffered anaphylaxis and a third had an acute asthma attack 10 minutes after their first ever dose of echinacea. The fourth patient suffered recurrent episodes of mild asthma each time echinacea was ingested, and the fifth developed a maculopapular rash within 2 days of ingestion which recurred when rechallenged. Three of the patients had positive SPT results. Three reported repeated spontaneous "challenges" and symptoms after further ingestion of echinacea. Fifty-one Australian adverse drug reports implicating echinacea were also reviewed. There were 26 cases suggestive of possible immunoglobulin E-mediated hypersensitivity (4 anaphylaxis, 12 acute asthma, 10 urticaria/angioedema). Of these 26 patients, age ranged from 2 to 58 years, 78% were female and >50% were known to be atopic. Four were hospitalized, 4 reacted after their first known exposure, and 1 patient suffered multiple progressive systemic reactions. Twenty percent of 100 atopic subjects who had never taken echinacea also had positive SPT results to this substance when tested by one of the authors in his office practice. CONCLUSION: Some atopic subjects have positive SPT results to echinacea in the absence of known exposure. Atopic subjects are also overrepresented in those experiencing reactions to echinacea. The possibility that cross-reactivity between echinacea and other environmental allergens may trigger allergic reactions in "echinacea-naïve" subjects is supported by the Australian data. Given its widespread (and largely unsupervised) community use, even rare adverse events become inevitable. Atopic patients should be cautioned appropriately.

Adult↗
PubMed2003

Efficacy and safety of echinacea in treating upper respiratory tract infections in children: a randomized controlled trial.

CONTEXT: Echinacea is a widely used herbal remedy for treatment of upper respiratory tract infections (URIs). However, there are few data on the efficacy and safety of echinacea in treating URIs in children. OBJECTIVES: To determine if Echinacea purpurea is effective in reducing the duration and/or severity of URI symptoms in children and to assess its safety in this population. DESIGN, SETTING, AND PARTICIPANTS: Randomized, double-blind, placebo-controlled trial of healthy children 2 to 11 years old recruited from a regional practice-based network and an alternative medical center in 4-month periods from 2000 through 2002. INTERVENTIONS: Study patients were randomized to receive either echinacea or placebo for up to 3 URIs over a 4-month period. Study medication was begun at the onset of symptoms and continued throughout the URI, for a maximum of 10 days. MAIN OUTCOME MEASURES: Primary outcomes were duration and severity of symptoms and adverse events recorded by parents; secondary outcomes included peak severity of symptoms, number of days of peak severity, number of days of fever, and a global assessment of severity of symptoms by parents of study children. RESULTS: Data were analyzed on 707 URIs that occurred in 407 children, including 337 URIs treated with echinacea and 370 with placebo. There were 79 children who completed their study period without having a URI. The median duration of URIs was 9 days (95% confidence interval, 8-10 days); there was no difference in duration between URIs treated with echinacea or placebo (P =.89). There was also no difference in the overall estimate of severity of URI symptoms between the 2 treatment groups (median, 33 in both groups; P =.69). In addition, there were no statistically significant differences between the 2 groups for peak severity of symptoms (P =.68), number of days of peak symptoms (1.60 in the echinacea group and 1.64 in the placebo group; P =.97), number of days of fever (0.81 in the echinacea group vs 0.64 in the placebo group; P =.09), or parental global assessment of severity of the URI (P =.67). Overall, there was no difference in the rate of adverse events reported in the 2 treatment groups; however, rash occurred during 7.1% of the URIs treated with echinacea and 2.7% of those treated with placebo (P =.008). CONCLUSIONS: Echinacea purpurea, as dosed in this study, was not effective in treating URI symptoms in patients 2 to 11 years old, and its use was associated with an increased risk of rash.

Child↗
PubMed2003

[History of a plant: the example of Echinacea].

In comparison with other medicinal plants, the history of use of Echinacea is relatively short. The plant originates from North America and was employed by the indigenous Indians. The first archaeological evidence dates from the 18th century. Included in the name Echinacea or purple coneflower are several species of the Asteraceae family: Echinacea purpurea (L.) Moench, Echinacea angustifolia DC. and Echinacea pallida (Nutt.) Nutt. Information about the use of the plant from traditional healers ranges from external application for wounds, burns and insect bites to the chewing of roots for toothache and throat infections, and internal application for pain, coughs, stomach cramps and snake bites. The interest of white settlers was also drawn to this medicinal plant. The first Echinacea preparation, known as Meyers Blood Purifier, arrived on the market around 1880, with rheumatism, neuralgia and rattlesnake bites as indications. At the beginning of the 20th century, Echinacea was the most frequently used plant preparation in the USA. Commercial cultivation was started in Germany around 1939. The introduction and cultivation of Echinacea in Switzerland by A. Vogel was around 1950. Chemists and pharmacologists became interested in Echinacea and many constituents are now known, such as polysaccharides, echinacoside, cichoric acid, ketoalkenes and alkylamides. The extracts exhibit immunostimulant properties and are mainly used in the prophylaxis and therapy of colds, flu and septic complaints. Although there are over 400 publications concerning the plant and dozens of preparations of Echinacea n the market, the true identity of the active principles still remains open.

Adjuvants, Immunologic↗
PubMed2005

The safety of herbal medicinal products derived from Echinacea species: a systematic review.

Echinacea spp. are native to North America and were traditionally used by the Indian tribes for a variety of ailments, including mouth sores, colds and snake-bites. The three most commonly used Echinacea spp. are E. angustifolia, E. pallida and E. purpurea. Systematic literature searches were conducted in six electronic databases and the reference lists of all of the papers located were checked for further relevant publications. Information was also sought from the spontaneous reporting programmes of the WHO and national drug safety bodies. Twenty-three manufacturers of echinacea were contacted and asked for data held on file. Finally our own departmental files were searched. No language restrictions were imposed. Combination products and homeopathic preparations were excluded. Data from clinical studies and spontaneous reporting programmes suggest that adverse events with echinacea are not commonly reported. Gastrointestinal upsets and rashes occur most frequently. However, in rare cases, echinacea can be associated with allergic reactions that may be severe. Although there is a large amount of data that investigates the efficacy of echinacea, safety issues and the monitoring of adverse events have not been focused on. Short-term use of echinacea is associated with a relatively good safety profile, with a slight risk of transient, reversible, adverse events. The association of echinacea with allergic reactions is supported by the present evaluation. While these reactions are likely to be rare, patients with allergy or asthma should carefully consider their use of echinacea. The use of echinacea products during pregnancy and lactation would appear to be ill-advised in light of the paucity of data in this area.

Adult↗
PubMedDate not supplied

Oral administration of freshly expressed juice of Echinacea purpurea herbs fail to stimulate the nonspecific immune response in healthy young men: results of a double-blind, placebo-controlled crossover study.

Echinacea extracts are widely used in European countries and in the United States as "immune-stimulating" agents. Even though the evidence to stimulate certain components of the nonspecific immune system (phagocytosis, macrophages, and production of cytokines) stems from in vitro experiments or studies after parenteral application, the commercially available Echinacea preparations used as drugs or supplements are for oral use. The aim of the study was to determine whether phagocytic activity and production of cytokines is stimulated by oral application of a commercially available Echinacea preparation. Forty healthy male volunteers (ages 20-40 years) participated in the study. They received either a freshly expressed juice of Echinacea purpurea herbs or placebo juice using a double-blind placebo-controlled crossover design with two treatment periods of 14 days and a wash-out period of 4 weeks in between. Endpoints for immune stimulation: phagocytic activity of polymorphonuclear leukocytes and monocytes measured by flowcytometry, production of tumor necrosis factor alpha (TNF)-alpha and Interleukin (IL)-1beta by LPS-stimulated blood monocytes. Echinacea purpurea herbs did neither enhance phagocytic activity of polymorphonuclear leukocytes nor that of monocytes when compared with placebo. Echinacea purpurea herbs did not influence the production TNF-alpha and IL-1beta by LPS-stimulated monocytes. Unexpectedly, Echinacea purpurea herbs decreased serum ferritin concentration (p = 0.0005). All other laboratory and safety data remained unchanged. The "immune stimulation" by Echinacea purpurea observed in vitro and after parenteral administration are not confirmed in healthy humans after oral intake. Other immunomodulatory effects may explain the benefits of Echinacea preparations in reducing duration and severity of upper-respiratory tract infections found in randomized, double-blind clinical trials.

Adjuvants, Immunologic↗
PubMed2004

Efficacy of a standardized echinacea preparation (Echinilin) for the treatment of the common cold: a randomized, double-blind, placebo-controlled trial.

BACKGROUND: Recently, echinacea has regained popularity as one of the treatments chosen most commonly by consumers with the expectation that it will reduce the severity and duration of the common cold. However, the results from a limited number of clinical trials for this application have thus far been inconclusive. This incongruity may be the result of investigators utilizing poorly standardized echinacea products, likely devoid of sufficient quantities of active constituents necessary to exert a definitive clinical effect. Therefore, a formulation containing alkamides, cichoric acid, and polysaccharides at concentrations of 0.25, 2.5, and 25 mg/mL, respectively, was prepared from freshly harvested Echinacea purpurea plants (commercially available as Echinilin, Natural Factors Nutritional Products, Inc., Vancouver, BC, Canada). The objective of this study was to test the efficacy of this highly standardized formulation in reducing the severity and duration of symptoms of a naturally acquired common cold. METHODS: In a randomized, double-blind, placebo-controlled trial, 282 subjects aged 18-65 years with a history of two or more colds in the previous year, but otherwise in good health, were recruited. The subjects were randomized to receive either echinacea or placebo. They were instructed to start the echinacea or placebo at the onset of the first symptom related to a cold, consuming 10 doses the first day and four doses per day on subsequent days for 7 days. Severity of symptoms (10-point scale: 0, minimum; 9, maximum) and dosing were recorded daily. A nurse examined the subjects on the mornings of days 3 and 8 of their cold. RESULTS: A total of 128 subjects contracted a common cold (59 echinacea, 69 placebo). The total daily symptom scores were found to be 23.1% lower in the echinacea group than in placebo in those who followed all elements of the study protocol (P<0.01). Throughout the treatment period, the response rate to treatments was greater in the echinacea group. A few adverse event profiles were observed in both groups. CONCLUSIONS: Early intervention with a standardized formulation of echinacea resulted in reduced symptom severity in subjects with naturally acquired upper respiratory tract infection. Further studies with larger patient populations appear to be warranted.

Adult↗
PubMed2003

Effect of dietary Echinacea purpurea on viremia and performance in porcine reproductive and respiratory syndrome virus-infected nursery pigs.

The effect of dietary Echinacea purpurea on performance, viremia, and ontogeny of the humoral antibody response against porcine reproductive and respiratory syndrome virus (PRRSV) infection was evaluated in weaned pigs. In three replicates, 120 weaned pigs (25 +/- 1 d of age; 8.46 +/- 0.48 kg of BW) from a PRRSV-naive herd were allotted randomly to one of eight pens (diets) in two separate rooms (four pens/room), with each pen containing five pigs. Pigs began one of four dietary treatments (as-fed basis) 1 wk before inoculation with PRRSV: 1) basal diet composed of corn, soybean meal, whey, and essential vitamins and minerals; 2) basal diet plus carbadox (0.055 g/kg of diet; as-fed basis); 3) basal diet plus Echinacea 2% (2% of the total diet); 4) basal diet plus Echinacea 4% (4% of the total diet). The diets were formulated to be isocaloric and isolysinic. Echinacea purpurea was purchased in powder form and determined by chemical analysis to contain 1.35% cichoric acid (as-fed basis). Seven days after starting the diets, all pigs in one room were intranasally inoculated with PRRSV isolate ATCC VR-2332 at a concentration of 10(4) tissue culture infectious dose50/mL. To monitor the effects of Echinacea and PRRSV challenge, BW and blood samples were obtained from all pigs at 7-d intervals. Serum samples were analyzed for the presence of PRRSV and PRRSV-specific antibodies. All challenged pigs became infected with PRRSV, and all unchallenged pigs remained free of infection. No differences (P > 0.10) in ADG, ADFI, or gain:feed (G:F) were observed in PRRSV-challenged compared with unchallenged animals. For PRRSV-challenged animals receiving diets supplemented with Echinacea at 2 or 4%, no differences (P > 0.10) were observed in ADG, ADFI, or G:F ratio. Among PRRSV-challenged pigs, dietary Echinacea did not affect (P > 0.10) the rate or level of the ELISA-detectable antibody response from d 7 to 42 or the level and duration of PRRSV in serum. For PRRSV-unchallenged animals receiving diets supplemented with Echinacea at 2 or 4%, no differences (P > 0.10) were observed in ADG, ADFI, and G:F ratio. Under the conditions of this study, dietary Echinacea did not enhance growth, exhibit antiviral effects to PRRSV, or show any evidence of immune enhancing properties.

Animal Feed↗
PubMed2004

Cytokine production by non-adherent mouse splenocyte cultures to Echinacea extracts.

BACKGROUND: Echinacea is commonly used in oral dosage as an immune stimulant to increase resistance to viral, bacterial and fungal infections of the upper respiratory tract. It has been suggested that Echinacea is able to stimulate innate immune responses, including those regulated by macrophages and natural killer cells. Indeed, macrophages respond to purified polysaccharide and alkylamide preparations. However, the mechanisms for stimulation of cells responsible for adaptive immunity have not been fully elucidated for other molecules present in Echinacea purpurea preparations. METHODS: Adherent and non-adherent mouse splenocyte populations were incubated in vitro with Echinacea, or with water or alcohol soluble Echinacea extract preparations. Supernatants were collected at 48-h post-incubation, and tested by standard ELISA for presence of secreted cytokines and proinflammatory mediators. RESULTS: Whole splenocyte populations were capable of producing significant amounts IL-6 (1014 pg/ml) in response to Echinacea preparations. The response was primarily contained towards products isolated to the water extract preparation; no IL-6 was produced upon challenge with the alcohol extract. The IL-6 response was produced by the non-adherent cellular population, which made 4912 pg/ml IL-6 when treated with water soluble extract at 1 mg/ml. Likewise, the water soluble extract of Echinacea was able to stimulate non-adherent splenocyte populations to produce TNF-alpha (2082 pg/ml), IL-10 (892 pg/ml) and MIP-1alpha (6486 pg/ml) from non-adherent splenocytes, but only significant concentrations of TNF-alpha and MIP-1alpha mediators were produced from adherent populations at similar dose concentrations. Neither population of splenocytes was capable of stimulating significant production of IFN-gamma, IL-2 or IL-12 to any preparation of Echinacea examined. CONCLUSIONS: The immune stimulatory ability of components contained within E. purpurea extracts offer insight into possible therapeutic potential of this product to regulate non-adherent lymphocytes in immune responses and activation events.

Alcohols↗
PubMed2000

Use of echinacea in medicine.

Echinacea, also known as the purple coneflower, is an herbal medicine that has been used for centuries, customarily as a treatment for the common cold, coughs, bronchitis, upper respiratory infections, and some inflammatory conditions. Research on echinacea, including clinical trials, is limited and largely in German. More information is needed before a definitive statement about the efficacy of echinacea can be made. Future work needs to clearly identify the species of echinacea and distinguish between the efficacy of the different plant parts (roots versus upper plant parts). Although many of the active compounds of echinacea have been identified, the mechanism of action is not known, nor is the bioavailability, relative potency, or synergistic effects of the active compounds known. Interpretation of existing literature suggests that echinacea should be used as a treatment for illness, not as a means for prevention of illness. The consensus of the studies reviewed in this article is that echinacea is indeed effective in reducing the duration and severity of symptoms, but that this effect is noted only with certain preparations of echinacea. Studies show that the plant and its active components affect the phagocytic immune system, but not the specifically acquired immune system.

Adjuvants, Immunologic↗