Double‐blind placebo controlled trial of the anxiolytic effects of a standardized Echinacea extract

Abstract

Earlier studies suggested that specific Echinacea preparations might decrease anxiety. To further study the issue, we performed a double blind, placebo controlled trial with a standardized Echinacea angustifolia root extract. Participants were volunteers scoring above 45 points on the state or on the trait subscale of the State Trait Anxiety Inventory (STAI). They were treated with 40 mg Echinacea or with placebo tablets twice daily for 7 days followed by a 3 week‐long washout period. Participants were also administered the Beck Depression Inventory (BDI) and the Perceived Stress Scale (PSS). In the Echinacea group, state anxiety scores decreased by approximately 11 points by the end of the treatment period, whereas the decrease was around 3‐points in the placebo group (p< 0.01). The effect maintained over the washout period. The difference from placebo was significant from the 7th day of treatment throughout. Changes were less robust with trait anxiety scores, but the preparation performed better than placebo in patients with high baseline anxiety. Neither BDI nor PSS scores were affected by the treatments. Adverse effects were rare and mild, and all were observed in the placebo group. These findings suggest that particular Echinacea preparations have significant beneficial effects on anxiety in humans.

The Safety and Efficacy of Botanicals with Nootropic Effects

“…There are other well-known botanicals currently used as dietary supplements that are only now emerging as potential nootropics. For example, an Echinacea angustifolia root extract has just recently been tested in a randomized, double-blind, placebo-controlled trial in subjects with anxiety [ 152 ]. Findings from this study were promising and showed a significant anxiolytic effect.…”

Role of medicinal plants in inhibiting SARS-CoV-2 and in the management of post-COVID-19 complications

“…Koidz. Ethanol extract of aerial parts its active principle, 4-hydroxyderricin improved myosin heavy chain degradation by suppressing expressions of MAFbx, MuRF-1 and myostatin Cardiac complications Kweon et al, 2019 Ethanol extract of aerial parts improved apoptosis via intrinsic and extrinsic pathways against AAP treated hepatotoxicity Liver related problem Choi et al, 2017 Xanthoangelol isolated from the hydroalcohol extract of aerial parts (1) inhibited monoamine oxidase and dopamine β-hydroxylase in rats Mental problem Kim et al, 2013 Asteraceae Echinacea purpurea L. Moench A double blind, placebo-controlled study (clinical study) decreased anxiety conditions Mental problem Haller et al, 2019 Hydroalcohol extract of aerial part decreased serum AST, BUN, total and direct bilirubin content and improved histopatholgical changes of kidney tissue by early fibrosis and proliferation Kidney complications Rezaie et al, 2013 Alk-8/9 isolated from the root showed good hepatoprotective activity against acute fulminant hepatitis condition in-vivo by increasing the expression of heme oxygenase (HO)-1 protein lipopolysaccharide/ D-galactosamine treated mice Liver related problem Hou et al, 2011 Erigeron breviscapus (Vaniot) Hand.-Mazz Scutellarin showed potent hepatoprotective effects by improving CYP2E1 and IκBα/NF-κB signaling pathways in carbon tetrachloride treated mice Liver related problem Miao et al, 2021 Scutellarin improved lung damage due to its antioxidant, antinflammatory and antiapoptotic effects in a bilateral hind limb ischemia–reperfusion rat model Lung related complications Ibrahim et al, 2019 Scutellarin improved renal function by reducing serum creatinine, blood urea nitrogen, urine total protein and microglobulin content Kidney complications Wu et al, 2018 Ethanol whole plant extract, ethyl acetate and aqueous fraction potently and noncompetitively inhibited GABA transaminase and succinic semialdehyde dehydrogenase enzymes in in-vitro assay due to the presence of flavonoids Parkinsonism Tao et al, 2008 …”

Anxiofit‐1 and reduction of subthreshold and mild anxiety: evaluation of a health claim pursuant to Article 14 of Regulation (EC) No 1924/2006

“…The fourth and most recent study submitted with the present application (Haller et al., , unpublished) is a randomised, parallel, two‐arm, double‐blind, placebo‐controlled, single‐centre study which investigates the effect of Anxiofit‐1 (80 mg/day; two tablets of 20 mg twice daily) given for 7 days vs placebo (identical to the test product containing only excipients) on state and trait anxiety.…”

“…The Panel considers that one human intervention study (Haller et al., , unpublished) shows an effect of Anxiofit‐1 (80 mg/day given for 7 days) on the state anxiety and not on the trait subscale in subjects with subthreshold or mild anxiety. These results are supported by two human intervention studies conducted with Anxiofit‐1 at 40 mg/day (Haller et al., , unpublished) for 7 days and 6 weeks, respectively, which, on their own, cannot be used for the substantiation of the claim either because of methodological limitations or because the results cannot be extrapolated to the target population for the claim.…”

“…The Panel also notes that all the human intervention studies submitted have been conducted in a similar setting, and that the results of the study by Haller et al. (, unpublished) have not been confirmed by other research groups.…”