The effects of an Echinacea preparation on synaptic transmission and the firing properties of CA1 pyramidal cells in the hippocampus

Echinacea purpurea extract intervention for counteracting neurochemical and behavioral changes induced by bifenthrin

This study was conducted to elucidate the possible protective efficiency of Echinacea purpurea hydroethanolic extract (EchEE) against bifenthrin (BIF)-induced neuro-chemical and behavioral changes in rats. Total phenolics content, reducing power and radical scavenging activity of EchEE were estimated. Four groups of adult male albino rats were used (10 rats each) as follows: 1) Control healthy rats ingested with placebo, 2) Healthy rats orally received EchEE (465 mg/kg/day), 3) Rats intoxicated with BIF (7mg/kg/day) dissolved in olive oil, and 4) Rats co-treated with EchEE (465 mg/kg/day) besides to BIF (7mg/kg/day) intoxication. After 30 days, some neuro-chemical and behavioral tests were assessed. The behavioral tests revealed that rats received BIF exhibited exploratory behavior and spatial learning impairments, memory and locomotion dysfunction, and enhanced anxiety level. Biochemical findings revealed that BIF induced-oxidative stress in the cortex and hippocampus; this was appeared from the significant rise in malondialdehyde (MDA) and nitric oxide (NO) levels, coupled with decreased catalase (CAT), superoxide dismutase (SOD), paraoxonase-1 (PON-1) activities, and reduced glutathione (GSH) level in both brain areas. Also, BIF induced a significant increase caspas-3, tumor necrosis factor alpha (TNF), and interleukin-1beta (IL-1ß) in both areas; dopamine and serotonin levels, and ACh-ase activity were markedly decreased in both areas. Interestingly, treatment of rats with EchEE in combination with BIF resulted in a significant decrease in oxidative stress damage, and modulation of the apoptotic and pro-inflammatory markers. Also, EchEE markedly improved behavioral activities and neurotransmitters level that were impaired by BIF. In conclusion, the present study clearly indicated that EchEE can attenuate brain dysfunction induced by pesticides exposure through preventing the oxidative stress. This may be attributed to its high antioxidant component.

Anticonvulsive and anti-epileptogenesis effects of Echinacea purpurea root extract, an involvement of CB2 receptor

OBJECTIVES

Phytocannabinoids beyond the Δ9-tetrahy-drocannabinol have shown anticonvulsive effects. Also, alkylamides from Echinacea purpurea have been proved as cannabinomimetics. We examined the effect of the hydroalcoholic root extract of E. purpurea on pentylenetetrazol (PTZ)-induced tonic-clonic seizures and kindling model of epileptogenesis and the involvement of CB2 receptors as the mediator of this effect.

METHODS

Male Wistar rats (200 ± 20 g) were used. Single intraperitoneal (i.p.) injection of PTZ (80 mg/kg) was used to induce tonic-clonic seizures. The kindling model of epileptogenesis was induced by daily injections of PTZ (37 mg/kg; i.p. for 15 days). Latency and duration of the stages were monitored for analysis. The hydroalcoholic root extract of E. purpurea was injected (i.p.) 20 min before seizure induction at the doses of 10, 50, 100 and 200 mg/kg. CB2 receptor antagonist SR144528 was injected (0.1 mg/kg; i.p.) 20 min before the Echinacea injection.

RESULTS

In the tonic-clonic model, pretreatment with E. purpurea at the doses of 100 and 200 mg/kg significantly increased latencies to S2-S6, while it significantly decreased S6 duration and mortality rate. SR144528 injection before the injection of 100 mg/kg of E. purpurea significantly prevented the effects of the extract on S4-S6 latencies. In the kindling model, E. purpurea at the doses of 100 and 200 mg/kg significantly delayed epileptogenesis and decreased mortality rate, while SR144528 injection before the injection of 100 mg/kg of E. purpurea significantly blocked this effect of the extract.

CONCLUSIONS

These findings revealed the anticonvulsive and antiepileptogenesis effects of the E. purpurea root extract, which can be mediated by CB2 receptors.

Can Echinacea be a potential candidate to target immunity, inflammation, and infection - The trinity of coronavirus disease 2019

Coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is an ongoing public health emergency. The pathogenesis and complications advanced with infection mainly involve immune-inflammatory cascade. Therefore, the therapeutic strategy relies on immune modulation, reducing infectivity and inflammation. Given the interplay of infection and immune-inflammatory axis, the natural products received attention for preventive and therapeutic usage in COVID-19 due to their potent antiviral and anti-immunomodulatory activities. Recently, Echinacea preparations, particularly E. purpurea, have been suggested to be an important antiviral agent to be useful in COVID-19 by modulating virus entry, internalization and replication. In principle, the immune response and the resultant inflammatory process are important for the elimination of the infection, but may have a significant impact on SARS-CoV-2 pathogenesis and may play a role in the clinical spectrum of COVID-19. Considering the pharmacological effects, therapeutic potential, and molecular mechanisms of Echinacea, we hypothesize that it could be a reasonably possible candidate for targeting infection, immunity, and inflammation in COVID-19 with recent recognition of cannabinoid-2 (CB2) receptors and peroxisome proliferator-activated receptor gamma (PPARγ) mediated mechanisms of bioactive components that make them notable immunomodulatory, anti-inflammatory and antiviral agent. The plausible reason for our hypothesis is that the presence of numerous bioactive agents in different parts of plants that may synergistically exert polypharmacological actions in regulating immune-inflammatory axis in COVID-19. Our proposition is to scientifically contemplate the therapeutic perspective and prospect of Echinacea on infection, immunity, and inflammation with a potential in COVID-19 to limit the severity and progression of the disease. Based on the clinical usage for respiratory infections, and relative safety in humans, further studies for the evidence-based approach to COVID-19 are needed. We do hope that Echinacea could be a candidate agent for immunomodulation in the prevention and treatment of COVID-19.

Possible Role of Fat Tissue in the Pharmacokinetics of Dodeca-2E,4E,8Z,10E/Z-tetraenoic Acid Isobutylamides after Oral Administration of Echinacea angustifolia Extract in Rats

Alkamides are one of the most important constituents of lipophilic extracts of Echinacea angustifolia roots. These compounds play an important role in the versatile pharmacological actions of this plant. The present study aimed to compare the concentrations of isomeric dodeca-2 E,4 E,8 Z,10 E/ Z-tetraenoic acid isobutylamides (DTAI) in brain and periepididymal fat tissues and blood plasma of rats. Thirty, 60, 240 and 720 min after the oral administration of E. angustifolia root extract, tissue and plasma concentrations were determined by reversed-phase HPLC with ESI-MS/MS detection. The calculated terminal t½ of the mixture of DTAI was 8.28 h, which indicates a relatively slow elimination. In the 0.5–4 h period the brain/plasma and fat/plasma concentration ratios were continuously above 3 and 18, respectively, followed by equilibrium at 12 h. Our results indicate substantial accumulation of alkamides in lipid-rich tissues, which presumably contributes to a maintained pharmacological action.

Echinacea for preventing and treating the common cold

BACKGROUND

Echinacea plant preparations (family Asteraceae) are widely used in Europe and North America for common colds. Most consumers and physicians are not aware that products available under the term Echinacea differ appreciably in their composition, mainly due to the use of variable plant material, extraction methods and the addition of other components.

OBJECTIVES

To assess whether there is evidence that Echinacea preparations are effective and safe compared to placebo in the prevention and treatment of the common cold.

SEARCH METHODS

We searched CENTRAL 2013, Issue 5, MEDLINE (1946 to May week 5, 2013), EMBASE (1991 to June 2013), CINAHL (1981 to June 2013), AMED (1985 to February 2012), LILACS (1981 to June 2013), Web of Science (1955 to June 2013), CAMBASE (no time limits), the Centre for Complementary Medicine Research (1988 to September 2007), WHO ICTRP and clinicaltrials.gov (last searched 5 June 2013), screened references and asked experts in the field about published and unpublished studies.

SELECTION CRITERIA

Randomized controlled trials (RCTs) comparing mono-preparations of Echinacea with placebo.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed eligibility and trial quality and extracted data. The primary efficacy outcome was the number of individuals with at least one cold in prevention trials and the duration of colds in treatment trials. For all included trials the primary safety and acceptability outcome was the number of participants dropping out due to adverse events. We assessed trial quality using the Cochrane 'Risk of bias' tool.

MAIN RESULTS

Twenty-four double-blind trials with 4631 participants including a total of 33 comparisons of Echinacea preparations and placebo met the inclusion criteria. A variety of different Echinacea preparations based on different species and parts of plant were used. Evidence from seven trials was available for preparations based on the aerial parts of Echinacea purpurea. Ten trials were considered to have a low risk of bias, six to have an unclear risk of bias and eight to have a high risk of bias. Ten trials with 13 comparisons investigated prevention and 15 trials with 20 comparisons investigated treatment of colds (one trial addressed both prevention and treatment).Due to the strong clinical heterogeneity of the studies we refrained from pooling for the main analysis. None of the 12 prevention comparisons reporting the number of patients with at least one cold episode found a statistically significant difference. However a post hoc pooling of their results, suggests a relative risk reduction of 10% to 20%. Of the seven treatment trials reporting data on the duration of colds, only one showed a significant effect of Echinacea over placebo. The number of patients dropping out or reporting adverse effects did not differ significantly between treatment and control groups in prevention and treatment trials. However, in prevention trials there was a trend towards a larger number of patients dropping out due to adverse events in the treatment groups.

AUTHORS' CONCLUSIONS

Echinacea products have not here been shown to provide benefits for treating colds, although, it is possible there is a weak benefit from some Echinacea products: the results of individual prophylaxis trials consistently show positive (if non-significant) trends, although potential effects are of questionable clinical relevance.