Eyebright Aerial Parts Extract
Also known as: Eyebright, Euphrasia rostkoviana Hayne, Euphrasia officinalis L.
Overview
Eyebright aerial parts extract is derived from the aboveground sections of the Euphrasia officinalis plant, a herb historically utilized in traditional medicine for various eye conditions. This extract is rich in bioactive compounds, including iridoids, phenolic acids, phenylpropane derivatives, and flavonoid glycosides. These constituents are believed to contribute to its observed antioxidant, antibacterial, and immunomodulatory properties. While traditionally applied as a supplementary therapy for eye ailments such as conjunctivitis, irritation, and inflammation, current scientific evidence is primarily based on in vitro studies. Clinical trials are limited, and comprehensive systematic reviews or meta-analyses on its efficacy in humans are currently lacking, indicating that its clinical applicability requires further robust research.
Benefits
Eyebright aerial parts extract has demonstrated several potential benefits, primarily in in vitro settings. Its main effects include significant antioxidant and anti-inflammatory activities. Studies using human corneal epithelial cells have shown that ethanol and ethyl acetate extracts can reduce pro-inflammatory cytokines (IL-1β, IL-6, TNF-α) and modulate anti-inflammatory IL-10, suggesting a role in mitigating ocular inflammation. These extracts also exhibit reactive oxygen species scavenging capabilities, indicating their potential to reduce oxidative stress. Secondary effects, such as antibacterial properties and potential immunomodulatory effects, have been reported but require further clinical validation. Traditionally, eyebright has been used for individuals experiencing eye irritation, conjunctivitis, and related inflammatory eye conditions. While in vitro studies show promising effects on cytokine modulation and reactive oxygen species scavenging at non-toxic concentrations, quantitative clinical effect sizes are not yet established due to the lack of human clinical trials. In vitro effects are typically observed within 24 hours, but long-term clinical data are unavailable.
How it works
The therapeutic actions of eyebright aerial parts extract are attributed to its diverse array of bioactive compounds, including iridoids, flavonoids, and phenolic acids. These compounds exert antioxidant effects by directly scavenging reactive oxygen species, thereby reducing oxidative stress within corneal cells. Its anti-inflammatory properties are mediated through the downregulation of pro-inflammatory cytokines and the modulation of nitric oxide release, which collectively contribute to reducing inflammatory responses. Furthermore, the extract appears to influence immunomodulatory pathways, potentially aiding in the reduction of conjunctival inflammation. However, the exact mechanisms of absorption and bioavailability in humans are not well characterized, as most of the mechanistic understanding is derived from cell culture models.
Side effects
The safety profile of eyebright aerial parts extract is not extensively documented due to a scarcity of human clinical trials. In vitro studies indicate that ethanol and ethyl acetate extracts are non-toxic to human corneal epithelial cells at concentrations up to 125 μg/mL. However, heptane extracts have shown cytotoxicity at lower concentrations (IC50 ~72.77 μg/mL), highlighting that the extraction solvent significantly impacts safety. Common side effects in clinical use are not well-documented. There are no reported drug interactions or contraindications in the current literature, but caution is advised given the limited safety data. Specific populations, such as pregnant women and children, have not been studied, and therefore, its use in these groups is not recommended without further research. Overall, while some in vitro data suggest a favorable toxicity profile for certain extract types, comprehensive human safety data are lacking.
Dosage
Currently, there are no standardized dosing guidelines for eyebright aerial parts extract due to the absence of robust human clinical trials. In vitro studies, which form the basis of much of the current understanding, have utilized extract concentrations ranging from 25 to 125 μg/mL to demonstrate biological activity. It is crucial to note that the extraction solvent significantly influences both the activity and safety of the extract; ethanol and ethyl acetate extracts are generally preferred over heptane extracts due to their superior safety and efficacy profiles. While topical formulations are commonly used for eye-related applications, pharmacokinetic data regarding absorption, distribution, metabolism, and excretion in humans are currently unavailable. Therefore, any use should be approached with caution and ideally under professional guidance.
FAQs
Is eyebright safe for eye use?
In vitro data suggest that ethanol and ethyl acetate extracts are non-toxic to corneal cells at certain concentrations. However, comprehensive clinical safety data in humans are insufficient, and heptane extracts can be cytotoxic.
Does eyebright cure eye infections?
There is no high-quality clinical evidence to confirm that eyebright cures eye infections. Traditional use and in vitro data suggest potential adjunctive benefits, but it should not replace conventional medical treatment.
How quickly does eyebright work?
In vitro effects have been observed within 24 hours of incubation. However, the clinical onset of benefit in humans is currently unknown due to a lack of clinical trials.
Are all eyebright extracts equally effective?
No, the effectiveness and safety of eyebright extracts vary significantly depending on the extraction solvent used. Ethanol and ethyl acetate extracts appear more promising than heptane extracts in terms of bioactivity and lower toxicity.
Research Sources
- https://pmc.ncbi.nlm.nih.gov/articles/PMC4115993/ – This in vitro study investigated the effects of Euphrasia officinalis extracts on human corneal epithelial cells. It found that ethanol and ethyl acetate extracts were non-toxic and effectively reduced pro-inflammatory cytokines (IL-1β, IL-6, TNF-α) while increasing anti-inflammatory IL-10, demonstrating antioxidant and anti-inflammatory properties. Conversely, heptane extracts showed cytotoxicity, highlighting the importance of extraction solvent.
- https://balkanmedicaljournal.org/text.php?lang=en&id=327 – This article, likely a part of the same research as the PMC link, further details the in vitro findings regarding Euphrasia officinalis extracts. It reinforces the observation that ethanol and ethyl acetate extracts exhibit beneficial anti-inflammatory and antioxidant effects on human corneal epithelial cells, supporting their potential for ocular health, while also noting the toxicity of heptane extracts.
- https://dergipark.org.tr/tr/pub/bmj/article/50470 – This source, likely another publication related to the Paduch et al. research, provides additional context or details on the in vitro study of Euphrasia officinalis. It confirms the findings that specific extracts (ethanol, ethyl acetate) are non-toxic and possess anti-inflammatory and antioxidant properties relevant to corneal health, contrasting with the cytotoxic effects of heptane extracts.
- https://dspace.uzhnu.edu.ua/jspui/bitstream/lib/17141/1/Euphrasia%20rostkoviana%20hayne%20-%20active%20components%20and%20biological%20activity%20for%20the%20treatment%20of%20eye%20disorders.pdf – This review synthesizes information on the active components and biological activity of Euphrasia rostkoviana (Eyebright) for eye disorders. It identifies key bioactive compounds and discusses their potential antioxidant, antibacterial, and immunomodulatory properties, providing a phytochemical context for the herb's traditional uses, though it notes the lack of clinical trial data.
- https://pmc.ncbi.nlm.nih.gov/articles/PMC11641456/ – This experimental study suggests potential neuroprotective properties of Euphrasia officinalis. While not directly focused on ocular disorders, it contributes to the broader understanding of the plant's pharmacological activities, indicating its diverse biological effects beyond traditional eye-related applications, though the details provided are limited.
