Eyebright Aerial Parts And Extract
Also known as: Eyebright, Euphrasia, Euphrasia officinalis
Overview
Eyebright, derived from the aerial parts and extracts of *Euphrasia officinalis*, is a traditional herbal remedy primarily used in folk medicine for various eye disorders, including conjunctivitis and inflammation. This herb contains several bioactive compounds, such as flavonoids, tannins, and iridoid glycosides (e.g., aucubin), which are believed to contribute to its purported anti-inflammatory, antioxidant, and antimicrobial properties. While its traditional use is extensive, scientific research on eyebright is still in its early to moderate stages. Most studies have been conducted in vitro or in preclinical models, with a notable scarcity of high-quality human clinical trials. Consequently, the overall quality of evidence supporting its efficacy and safety in humans is considered low to moderate, as rigorous systematic reviews or meta-analyses are largely absent.
Benefits
Eyebright exhibits several potential benefits, primarily demonstrated in in vitro studies. Its primary effects include significant antioxidant activity, which may help protect ocular cells from oxidative stress, as shown in multiple extract analyses. It also demonstrates anti-inflammatory effects by modulating pro-inflammatory cytokines (IL-1β, IL-6, TNF-α) and increasing anti-inflammatory cytokines (IL-10) in corneal epithelial cells. Furthermore, eyebright shows potential antimicrobial effects against bacterial and viral eye infections, attributed to compounds like aucubin. Beyond eye health, some in vitro studies suggest a secondary neuroprotective potential, improving the viability of neuroblastoma cells exposed to amyloid-beta peptides. While these findings are promising, the clinical relevance to human patients with eye inflammation or infection, or for neuroprotection, remains largely unconfirmed due to the limited number of large-scale, well-designed human randomized controlled trials.
How it works
Eyebright's mechanism of action is multifaceted, primarily attributed to its rich phytochemical composition. Its antioxidant activity stems from the ability of its compounds to scavenge free radicals. The herb exerts immunomodulatory effects by reducing the production of pro-inflammatory cytokines and enhancing anti-inflammatory cytokines in corneal cells, thereby mitigating inflammation. Its antimicrobial properties are thought to be due to specific iridoid glycosides, such as aucubin, which may directly inhibit microbial growth. Additionally, some research suggests neuroprotective effects, possibly through the inhibition of amyloid-beta toxicity and enhancement of mitochondrial function. However, detailed absorption and bioavailability data in humans are currently lacking, with most mechanistic insights derived from cell culture models.
Side effects
The safety profile of eyebright is not comprehensively documented in humans due to a lack of extensive clinical trials. In vitro studies suggest that eyebright extracts, particularly ethanol and ethyl acetate extracts, appear safe at low to moderate concentrations, showing minimal toxicity to corneal cells up to 125 μg/mL. However, a heptane extract demonstrated toxicity at concentrations exceeding 25 μg/mL, with an IC50 of approximately 73 μg/mL in corneal cells. There are no reported common or rare side effects from human clinical trials, as such trials are scarce. Information regarding drug interactions and contraindications is also not well-documented. Given the limited clinical safety data, caution is advised when considering the use of eyebright, especially for long-term or systemic applications. Comprehensive human safety data are urgently needed to establish its full safety profile.
Dosage
Currently, there are no established dosing guidelines for eyebright derived from robust human clinical trials. The concentrations used in in vitro studies typically range from low μg/mL up to 125 μg/mL, but translating these concentrations to safe and effective human oral or topical dosages is not straightforward. Traditionally, eyebright has been used in topical applications or as herbal infusions. However, standardized dosing protocols and information regarding its bioavailability in humans remain uncharacterized. Without sufficient clinical data, specific dosage recommendations cannot be provided, and any use should be approached with caution due to the lack of evidence-based dosing parameters and safety thresholds.
FAQs
Is eyebright extract effective for eye infections?
In vitro and ethnopharmacological evidence suggests anti-inflammatory and antimicrobial properties, but robust human clinical trials are lacking to confirm its effectiveness for eye infections.
Is it safe for long-term use?
Safety data for long-term human use are insufficient. While in vitro studies show low toxicity at moderate doses, comprehensive human safety data are needed before recommending long-term use.
How quickly does it work?
In vitro effects have been observed within 24 hours. However, the clinical onset of effects in humans is currently unknown due to a lack of human studies.
Can it be used with other eye medications?
There is no data available on potential interactions between eyebright and other eye medications. Therefore, caution is recommended, and consultation with a healthcare professional is advisable.
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 exhibited anti-inflammatory properties by modulating cytokines, while a heptane extract showed toxicity at higher concentrations. The study highlights the potential anti-inflammatory action of eyebright but notes the need for further research.
- https://pmc.ncbi.nlm.nih.gov/articles/PMC11641456/ – This in vitro study explored the antioxidant and neuroprotective effects of *Euphrasia officinalis* extracts on human neuroblastoma cells. It demonstrated that ethyl acetate and butanolic extracts were most effective in protecting cells against amyloid-beta toxicity, suggesting potential benefits beyond ocular health. The findings are preliminary and require further investigation.
- https://www.wellgreenherb.com/knowledge/what-is-eyebright-extract-used-for- – This source provides a narrative review of the traditional uses of eyebright, particularly for eye infections and inflammation. It discusses the role of flavonoids and iridoids in contributing to the herb's effects. However, it emphasizes the lack of controlled clinical trials to validate these traditional claims.
- https://farfar.pharmacy.bg.ac.rs/bitstream/handle/123456789/624/622.pdf?sequence=1&isAllowed=y – This document, likely a research paper or review, discusses various aspects of *Euphrasia officinalis*, including its chemical composition and traditional uses. It contributes to the understanding of the plant's bioactive compounds and their potential roles in its purported therapeutic effects, aligning with ethnopharmacological knowledge.