Alder Buckthorn Bark Extract
Also known as: Alder buckthorn, buckthorn bark, Rhamnus frangula, Frangula alnus
Overview
Alder buckthorn bark extract is derived from the bark of *Frangula alnus*, a shrub native to Europe and parts of Asia. It is primarily recognized and used as a stimulant laxative for the short-term relief of constipation. The extract contains active compounds such as hydroxyanthraquinone glycosides (e.g., emodin, frangulin, iso-emodin) and flavonoids, which are responsible for its pharmacological effects. While its main application is for digestive health, research also explores its potential antimicrobial, antiviral, and neuroprotective properties, though these applications are less established and require further clinical validation. The extract is available in various forms, including dried bark, decoctions, and liquid extracts, and its use is supported by traditional practices and some clinical studies, particularly for its laxative effects.
Benefits
The primary and most well-supported benefit of Alder buckthorn bark extract is its stimulant laxative action for the relief of constipation. Clinical data and extensive traditional use indicate that doses of 0.5–2.5 g of dried bark or equivalent extracts effectively increase bowel motility and secretion, providing relief comparable to other anthraquinone laxatives like cascara sagrada. The onset of this effect typically occurs within 6–12 hours after oral administration. Secondary benefits, though less clinically established, include in vitro antimicrobial activity against certain bacterial strains, suggesting a potential role in gut microbiota balance. Antiviral activity, specifically emodin's inhibition of herpes simplex virus replication, has been observed in cell studies. Additionally, preclinical research suggests potential neuroprotective effects through the inhibition of tau protein aggregation, which is relevant to Alzheimer's disease. These secondary effects, however, require significant further validation through human clinical trials. The laxative benefit is primarily for adults experiencing occasional constipation, with safety and efficacy in children, pregnant, or lactating women not yet established.
How it works
The laxative effect of Alder buckthorn bark extract is primarily mediated by its hydroxyanthraquinone glycosides. These compounds are inactive until metabolized by gut bacteria in the colon into active aglycones. These active metabolites then stimulate colonic peristalsis, increasing the muscular contractions of the large intestine, and simultaneously inhibit the absorption of water and electrolytes from the colon. This dual action leads to increased intestinal motility and a higher water content in the stool, facilitating bowel movements. The absorption of these active compounds into the bloodstream is limited, meaning their effects are predominantly localized to the colon. Beyond its laxative action, anthraquinones may exert antimicrobial effects by disrupting bacterial cell metabolism, and compounds like emodin may interfere with viral replication and protein aggregation pathways in vitro.
Side effects
Alder buckthorn bark extract is generally considered safe for short-term use (up to 7–10 days) at recommended dosages. However, long-term or excessive use can lead to significant adverse effects. Common side effects, occurring in over 5% of users, include abdominal cramps, diarrhea, and electrolyte imbalance, particularly hypokalemia (low potassium levels). Less common side effects (1–5%) may include muscle weakness, nausea, and vomiting, especially if fresh bark is consumed, which is highly discouraged. Rare but severe side effects (<1%) can include severe dehydration and cardiac arrhythmias, which are typically a consequence of prolonged electrolyte disturbances. Alder buckthorn can interact with other medications; it may have additive effects with other laxatives and can exacerbate hypokalemia, posing risks for individuals taking cardiac glycosides or diuretics. It is contraindicated in cases of intestinal obstruction, inflammatory bowel disease, pregnancy, breastfeeding, and in individuals with known hypersensitivity. Its use is not recommended for children, pregnant, or lactating women due to insufficient safety data.
Dosage
The minimum effective dose for Alder buckthorn bark extract is approximately 0.5 g of dried bark or an equivalent extract. The optimal dosage range for adults is typically 0.5–2.5 g of dried bark daily. Alternatively, 2–5 mL of a 1:1 liquid extract (containing 25% alcohol) can be taken three times daily. It is crucial not to exceed 2.5 g of dried bark daily and to limit use to a maximum of 7–10 days to avoid adverse effects. For best results, the supplement is usually taken at bedtime to induce a bowel movement the following morning. It can be consumed as dried bark capsules, decoctions (prepared by steeping 2 g of bark in 150 mL of boiling water for 5–10 minutes), or liquid extracts. The efficacy of the anthraquinone glycosides relies on bacterial metabolism in the gut, so individual gut flora health may influence its effectiveness. While no specific cofactors are required, adequate hydration and dietary fiber intake can support and enhance the laxative effect.
FAQs
Is alder buckthorn safe for long-term use?
No, prolonged use exceeding 10 days is not recommended as it can lead to serious side effects, including electrolyte imbalances and potential bowel dependency.
How quickly does it work?
Alder buckthorn typically produces a bowel movement within 6–12 hours after oral administration, making it suitable for bedtime dosing.
Can it be used for other conditions?
While preclinical studies show potential antimicrobial and antiviral effects, these are not yet clinically established or recommended for treatment.
Is fresh bark safe?
No, fresh bark is toxic and can cause severe vomiting. Only dried or heat-processed bark should be used for medicinal purposes.
Does it cause dependency?
Chronic use of stimulant laxatives like alder buckthorn can lead to bowel dependency, where the bowel becomes reliant on the laxative to function. Therefore, it should only be used short-term.
Research Sources
- https://pmc.ncbi.nlm.nih.gov/articles/PMC9607076/ – This experimental study by Kledecka et al. (2022) investigated the extraction efficiency and antimicrobial properties of *F. alnus* bark extracts. It found that alcoholic extracts yielded higher amounts of anthranoids and demonstrated varying degrees of antimicrobial activity against different bacterial strains in vitro. The study provides good preclinical data on the extract's potential but lacks human clinical trials.
- https://www.webmd.com/vitamins/ai/ingredientmono-850/alder-buckthorn – WebMD's summary on Alder Buckthorn highlights its effectiveness as a stimulant laxative for short-term constipation relief, with typical doses ranging from 0.5–2.5 g of dried bark. It notes an onset of action within 6–12 hours and details common gastrointestinal side effects and electrolyte disturbances, consistent with other stimulant laxatives. It emphasizes the importance of short-term use due to safety concerns.
- https://www.rxlist.com/supplements/alder_buckthorn.htm – RxList provides a clinical overview of Alder Buckthorn, confirming its use for short-term constipation relief at doses of 0.5–2.5 g of dried bark. It outlines the safety profile, including potential adverse effects like abdominal cramps, diarrhea, and electrolyte imbalance, particularly with prolonged use. The summary also lists contraindications and drug interactions, reinforcing the need for cautious and short-term administration.