Home Ingredients Frangula Bark (Alder Buckthorn, Rhamnus frangula)

Frangula Bark (Alder Buckthorn, Rhamnus frangula)

Rhamnus frangula (Frangula alnus)
Evidence Level
Preliminary
5 Clinical Trials
5 Documented Benefits
1/5 Evidence Score

Frangula bark is the dried bark of alder buckthorn (Rhamnus frangula, also called Frangula alnus), a European shrub. It is a stimulant laxative: colon bacteria convert its glucofrangulins and frangulins into emodin-9-anthrone, which speeds colonic transit and draws water into the stool. The bark must be stored for at least a year before use, because fresh bark causes vomiting. EU regulators accept it as an herbal medicine for short-term use in occasional constipation, but their review found no controlled clinical studies of frangula alone. The EU monograph limits use to 1 week and advises trying diet changes or bulk-forming fiber first. Under EU food law, bark preparations containing hydroxyanthracene derivatives have been under scrutiny since 2021 over genotoxicity concerns, and a July 2026 draft regulation would ban them in foods if adopted.

Studied Dose No controlled trial has tested frangula bark alone. EU monograph: a preparation equal to 10 to 30 mg hydroxyanthracene derivatives (as glucofrangulin A) once daily at night, or a tea with no more than 30 mg in 150 ml boiling water. No more than 1 week; up to 2 to 3 doses that week usually suffice.
Active Compound Hydroxyanthracene (anthranoid) glycosides: the diglycosides glucofrangulin A and B and the monoglycosides frangulins A, B and C, which colon bacteria convert to emodin-9-anthrone. Pharmacopoeia-grade bark contains at least 7% glucofrangulins, expressed as glucofrangulin A.

Benefits

Short-term bowel movement support recognized in the EU herbal monograph

EU herbal medicine regulators accept frangula bark as well-established use for short-term relief of occasional constipation. Their 2019 review found no controlled clinical studies of frangula alone, so the decision rests on pharmacology, expert opinion, long clinical experience and trials of related laxatives such as senna and aloe.

Supported by Trial 1, Trial 2

Overnight action once colon bacteria activate its glycosides

Frangula glycosides only work after colon bacteria convert them, so a dose taken at night acts after a delay of 8 to 12 hours, according to the EU monograph. The one human dose observation the EU review cites is an old report in which 0.6 g of powdered bark (12 mg anthranoids) had a laxative effect after 6 to 24 hours.

Supported by Trial 1, Trial 2

Combination laxative routine with sterculia and frangula after colostomy surgery

In a randomized trial in 45 colostomy patients, a set protocol whose first-line products were a sterculia fiber and frangula bark product plus liquid paraffin, with polyethylene glycol as second line, led to fewer cases of stool buildup on X-ray than laxatives chosen case by case (1 versus 7 episodes, P = 0.05). Frangula was one of several products, so its own effect cannot be separated.

Supported by Trial 1

Frangula in a three-herb laxative blend in a small uncontrolled study

In an older Bulgarian report, 32 patients with stomach or duodenal complaints and sluggish bowels took a blend of frangula, bitter orange and caraway, and the authors reported daily bowel movements in 90.6% and movements every second day in the rest. There was no control group, the abstract gives no dose, and frangula was not tested alone.

Supported by Trial 2

Antioxidant activity of bark extract in test tubes (lab study)

In test-tube assays, a frangula bark extract showed moderate antioxidant capacity, linked to its high phenolic content, while emodin alone did not. The same study found that the extract killed human white blood cells and damaged their DNA at high concentrations, so this lab result does not show any antioxidant benefit in people.

Supported by Trial 3, Trial 4

Mechanism of action

1

Activation by colon bacteria

Glucofrangulins and frangulins are glycosides that human digestive enzymes do not split, so little is absorbed in the upper gut. Bacteria in the large intestine convert them into the active metabolite, emodin-9-anthrone. Some aglycones are then absorbed and conjugated, and rhein, emodin and traces of chrysophanol appear in human urine.

2

Faster transit through the large intestine

The active anthrone stimulates the motility of the large intestine, which speeds the passage of stool through the colon. The EU monograph classes frangula as a contact laxative (ATC code A06AB).

3

Less water absorbed and more secreted in the colon

The EU monograph describes an anti-absorptive effect, in which less water, sodium and chloride is absorbed by the colon lining, and a secretory effect, in which tight junctions loosen and water and electrolytes are secreted into the colon. More fluid stays in the stool.

4

Why the bark is stored before use

In fresh bark the glycosides are in a reduced anthrone form that is thought to cause serious stomach side effects, and older texts note that fresh bark causes vomiting. Storage lets these compounds oxidize, which raises the frangulin content, so the EU review states that the bark should not be used until it has been stored for at least 1 year.

Clinical trials

1
Standard Laxative Protocol Including Sterculia With Frangula (Normacol Plus) After Colostomy Surgery: RCT
PubMed

Randomized controlled trial at 2 acute care hospitals in south-eastern Sydney comparing a standardized postoperative laxative protocol (first line: sterculia with frangula bark, sold as Normacol Plus, and liquid paraffin; second line: polyethylene glycol) with laxatives given as the surgical team preferred. (Stott et al. 2012, J Wound Ostomy Continence Nurs)

45 patients who had colostomy surgery (19 on the protocol, 26 in the comparison group).

Fecal loading on plain abdominal X-ray occurred once in the protocol group versus 7 times in the comparison group (P = 0.05), and nurses changed empty stoma bags more often in the comparison group (P = 0.03). Frangula was one ingredient of one first-line product, so the trial cannot show its separate effect. Data collection stopped after 3 years because surgeons adopted the protocol for routine care.

2
Frangula, Bitter Orange and Caraway Blend in Patients With Sluggish Bowels: Uncontrolled Study
PubMed

Uncontrolled clinical report (article in Bulgarian with an English abstract) of a laxative herb combination of Rhamnus frangula, Citrus aurantium and Carum carvi, given alongside a comfrey and calendula combination for the main stomach complaint. (Matev et al. 1981, Vutr Boles)

32 patients with duodenal ulcer or gastroduodenitis and accompanying constipation (the abstract lists 19 of each, which does not add up to 32).

The authors reported daily bowel movements in 90.6% of patients and movements every second day in 9.4%, and no effect of the herb blend on the stomach lining or on ulcer healing. With no control group, three herbs in one blend, no dose in the abstract and no adverse event data, this does not show what frangula itself does.

3
Frangula Bark Extract and Emodin in Human Lymphocytes: Lab Study
PubMed

In vitro study of a Frangula alnus bark extract and its constituent emodin in cultured human peripheral blood lymphocytes, with test-tube antioxidant assays (DPPH, ABTS and FRAP). (Brkanac et al. 2015, Regul Toxicol Pharmacol)

Human peripheral blood lymphocytes in culture; no people were dosed.

The bark extract caused cell death and DNA damage at 500 μg/ml and changed reactive oxygen species levels at 250 μg/ml; emodin caused cell death at 150 μg/ml and DNA damage at 200 μg/ml. The extract, but not emodin, showed moderate antioxidant capacity (phenolic content 116.07 mg/g). The authors concluded that frangula bark and emodin-containing preparations should be used with caution.

4
Frangula Extract and Emodin Toxicity in Human Cell Lines: Lab Study
PubMed

In vitro study of an ethyl acetate extract of Frangula alnus and emodin in human liver (HepG2) and colon (HCT116) tumor cell lines and normal lung fibroblasts (MRC-5). (Vuletić et al. 2023, Mutat Res Genet Toxicol Environ Mutagen)

Human cell lines in culture; no people were dosed.

Both the extract and emodin reduced cell viability, caused cell cycle arrest and triggered cell death, including in the normal fibroblasts, so no notable selectivity was seen. Both showed strong genotoxic potential in the comet assay in all cell lines. The extract also showed antioxidant activity in test-tube assays.

5
Frangula Bark Extracts and Selected Bacterial Strains: Lab Study
PubMed

Laboratory study comparing Frangula alnus bark extracts made with water, methanol, ethanol or isopropanol, their chemical makeup and their effects on selected bacterial strains. (Kledecka et al. 2022, Plants (Basel))

Bacterial cultures, including Pseudomonas strains and a Lactobacillus strain; no people were dosed.

Frangulin was confirmed as a main compound in the extracts. Pseudomonas fluorescens was particularly sensitive, other Pseudomonas strains showed practically no effect, and ethanolic extracts acted most strongly. The extracts had no direct effect on the tested Lactobacillus strain. This is culture work with no people dosed, so it does not show any effect in humans.

Side effects and drug interactions

Common Potential side effects

Abdominal pain, cramping and liquid stools can occur, especially in people with a sensitive bowel or after too large a dose; the EU monograph says to lower the dose if this happens.
Use beyond a brief period may impair normal bowel function and lead to reliance on laxatives; the EU monograph advises against long-term use and says to try diet changes or bulk-forming fiber first.
Long-term use can cause loss of water and electrolytes, especially potassium, and may lead to protein or blood in the urine. Overdose or misuse causes griping pain and severe diarrhea.
Chronic use can darken the lining of the colon (pseudomelanosis coli), which usually fades after stopping. In one reported case, a patient taking an aloe, rheum and frangula product developed it within 10 months.
Studies on long-term anthranoid laxative use and colorectal tumors disagree: one endoscopy study linked colon pigmentation to adenomas and cancer, while a later prospective case-control study of 554 people found no increased risk. Neither study looked at frangula on its own.
EU food safety experts concluded in 2018 that hydroxyanthracene derivatives should be treated as genotoxic and carcinogenic unless shown otherwise, and in 2024 they could not establish the safety of frangula bark preparations. Lab studies of frangula extract show DNA damage in human cells.
Chronic overdose of anthranoid laxatives may cause toxic hepatitis; the EU review found no reports linked to frangula itself.
Fresh, unstored bark causes vomiting. Yellow or red-brown discoloration of urine, which the EU monograph calls not clinically significant, and allergic reactions such as itching, hives or rash can occur.
Not for use in pregnancy, while breastfeeding or in children under 12, or with bowel blockage, inflammatory bowel disease, appendicitis, abdominal pain of unknown cause or severe dehydration (EU monograph).
A US lactation database advises avoiding buckthorn products while breastfeeding because they might cause loose stools in the infant.

Important Drug interactions

Digoxin and other cardiac glycosides: potassium loss from long-term use can strengthen their effect; ask a doctor before combining.
Antiarrhythmic drugs and medicines that prolong the QT interval: low potassium can interact with them; ask a doctor before combining.
Diuretics, corticosteroids and licorice root can add to potassium loss when taken with frangula.
Antiplatelet drugs: in lab work frangulin B reduced platelet clumping, but there are no human data and EU reviewers judged the evidence too thin to give advice.

Frequently asked questions about Frangula Bark (Alder Buckthorn, Rhamnus frangula)

Why does frangula bark have to be aged before use?

Fresh bark contains its glycosides in a reduced anthrone form that is thought to cause serious stomach side effects, and older texts note that fresh bark causes vomiting. During storage these compounds oxidize, so the EU review states that the bark should not be used until it has been stored for at least 1 year. Do not use freshly stripped bark.

Is frangula bark still allowed in food supplements in the EU?

Since 2021, EU food law has kept frangula bark preparations containing hydroxyanthracene derivatives under scrutiny, and emodin, one of the bark's constituents, is on the prohibited list for foods. EFSA could not establish their safety in 2024, and a draft regulation sent to the Council in July 2026 would ban them in foods if adopted. The EU herbal medicine monograph is a separate framework from these food rules.

How is frangula bark different from senna and cascara?

All three are anthranoid stimulant laxatives with similar cautions. Frangula and cascara are barks of related Rhamnus shrubs, and older texts describe frangula as a mild purgative similar to cascara. Frangula's glycosides are converted in the colon to emodin-9-anthrone, while senna's sennosides become rhein anthrone. Senna has placebo-controlled trials; frangula alone has none.

Is alder buckthorn the same as sea buckthorn?

No. Alder buckthorn (Rhamnus frangula) bark is a strong laxative, while sea buckthorn (Hippophae rhamnoides) is a different plant whose berries and oil are used as foods. The US LactMed database warns not to confuse the two. Check the Latin name on the label.

Does regular use change the color of the colon lining?

Yes. Chronic use of anthranoid laxatives such as frangula can cause pseudomelanosis coli, a brown pigmentation of the colon lining, which usually fades after stopping. In one reported case it developed within 10 months. It is a sign of long-term use, which the EU monograph advises against.

Can I take frangula bark every day?

No. The EU monograph says long-term use of stimulant laxatives should be avoided, because use beyond a brief period may impair normal bowel function and lead to reliance on laxatives. It limits use to 1 week, advises trying a change of diet or a bulk-forming fiber laxative first, and says the cause should be found if a laxative is needed every day.

What is Frangula Bark?

Frangula bark is the dried bark of alder buckthorn (Rhamnus frangula, also called Frangula alnus), a European shrub. It is a stimulant laxative: colon bacteria convert its glucofrangulins and frangulins into emodin-9-anthrone, which speeds colonic transit and draws water into the stool.

What is Frangula Bark used for?

NutraSmarts does not list Frangula Bark under a health category. What the research covers: EU herbal medicine regulators accept frangula bark as well-established use for short-term relief of occasional constipation.

What is the recommended dosage of Frangula Bark?

No controlled trial has tested frangula bark alone. EU monograph: a preparation equal to 10 to 30 mg hydroxyanthracene derivatives (as glucofrangulin A) once daily at night, or a tea with no more than 30 mg in 150 ml boiling water. Always follow the product label and check with a healthcare provider for personal advice.

Is Frangula Bark safe, and does it have side effects?

Side effects and cautions reported for Frangula Bark include: Abdominal pain, cramping and liquid stools can occur, especially in people with a sensitive bowel or after too large a dose; the EU monograph says to lower the dose if this happens. It may also interact with some medications. Frangula Bark is not right for everyone, so check with a healthcare provider first if you are pregnant or breastfeeding, have a medical condition, or take prescription medication.

Does Frangula Bark interact with any medications?

Possible interactions include: Digoxin and other cardiac glycosides: potassium loss from long-term use can strengthen their effect; ask a doctor before combining. Antiarrhythmic drugs and medicines that prolong the QT interval: low potassium can interact with them; ask a doctor before combining. If you take prescription medication, check with a pharmacist or doctor before using it.

How strong is the scientific evidence for Frangula Bark?

NutraSmarts rates the evidence for Frangula Bark as Preliminary (1 out of 5). It is backed by 5 study summaries and 16 cited references summarized on this page. A higher rating reflects more, larger, and better-designed human studies.

References(16 citations)

Evidence ratings on NutraSmarts are based on the totality of human clinical research, with emphasis on randomized controlled trials, meta-analyses, and systematic reviews. The references below directly support claims made throughout this page.

  1. European Medicines Agency, Committee on Herbal Medicinal Products (HMPC). European Union herbal monograph on Rhamnus frangula L., cortex. Final, Revision 1. EMA/HMPC/726261/2016. European Medicines Agency. 2019;Adopted by the HMPC 25 September 2019..SourceUsed to support: Not PubMed-indexed; official EU monograph, read in full. Well-established use for short-term use in occasional constipation; 10 to 30 mg hydroxyanthracene derivatives (as glucofrangulin A) once daily at night, or a tea with no more than 30 mg in 150 ml boiling water; no more than 1 week. Describes bacterial conversion to emodin-9-anthrone, motility and secretory effects, an 8 to 12 hour delay, pseudomelanosis coli, electrolyte loss, urine discoloration and interactions with cardiac glycosides, antiarrhythmics, QT-prolonging drugs, diuretics, corticosteroids and licorice root. Section 4.4 warns that long-term use of stimulant laxatives should be avoided because use beyond a brief period may lead to impaired bowel function and dependence on laxatives, that the cause should be investigated if laxatives are needed every day, and that frangula preparations should only be used if a change of diet or bulk-forming agents does not work. Contraindicated (section 4.3) in pregnancy, lactation, children under 12, intestinal obstruction, inflammatory bowel diseases, appendicitis, abdominal pain of unknown origin and severe dehydration.
  2. European Medicines Agency, Committee on Herbal Medicinal Products (HMPC). Assessment report on Rhamnus frangula L. cortex. Final, Revision 1. EMA/HMPC/483550/2018. European Medicines Agency. 2019;Dated 25 September 2019. Revision 1 rapporteurs L Anderson and J Wiesner (first assessment C Werner)..SourceUsed to support: Not PubMed-indexed; official EU assessment report, read. States that the only clinical investigations of frangula bark test it in combination products, that there are no controlled clinical studies or clinical safety studies of frangula alone, and that efficacy is taken from pharmacology, expert opinion, clinical experience and senna and aloe data. Cites an old report of 0.6 g powdered bark (12 mg anthranoids) acting in 6 to 24 hours, notes that fresh bark causes vomiting and that bark should be stored for at least 1 year, and reports in vitro platelet effects of frangulin B with no human data.
  3. European Commission. Commission Regulation (EU) 2021/468 of 18 March 2021 amending Annex III to Regulation (EC) No 1925/2006 of the European Parliament and of the Council as regards botanical species containing hydroxyanthracene derivatives. Official Journal of the European Union. 2021;OJ L 96, 19.3.2021, p. 6..SourceUsed to support: Not PubMed-indexed; EU regulation, read in full. Added aloe-emodin, emodin, danthron and all preparations in which they are present, and preparations from the leaf of Aloe species containing hydroxyanthracene derivatives, to Part A (prohibited) of Annex III. Placed preparations from the bark of Rhamnus frangula L. and Rhamnus purshiana DC. containing hydroxyanthracene derivatives, along with senna and rhubarb preparations, under Union scrutiny in Part C, based on the 2018 EFSA opinion.
  4. European Commission; Council of the European Union. Draft Commission Regulation (EU) amending Annex III to Regulation (EC) No 1925/2006 as regards certain botanical species containing hydroxyanthracene derivatives (SANTE/1196/2024 Rev.3, Council document 11964/26). Council of the European Union. 2026;Cover note dated 15 July 2026; Commission document D099926/3..SourceUsed to support: Not PubMed-indexed; draft EU regulation sent to the Council, read. Would move preparations from the bark of Rhamnus frangula L. and Rhamnus purshiana DC. containing hydroxyanthracene derivatives, and the senna and rhubarb entries, from Part C to Part A (prohibited) of Annex III, because the 2024 EFSA opinion could not establish their safety. Foods already lawfully on the market could stay for 12 months after entry into force (Article 2). A draft, not yet in force when read.
  5. EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS), Younes M, Aggett P, Aguilar F, Crebelli R, Filipič M, Frutos MJ, Galtier P, Gott D, Gundert-Remy U, Kuhnle GG, Lambré C, Leblanc JC, Lillegaard IT, Moldeus P, Mortensen A, Oskarsson A, Stankovic I, Waalkens-Berendsen I, Woutersen RA, Andrade RJ, Fortes C, Mosesso P, Restani P, Pizzo F, Smeraldi C, Papaioannou A, Wright M. Safety of hydroxyanthracene derivatives for use in food. EFSA J. 2018;16(1):e05090. doi: 10.2903/j.efsa.2018.5090.PubMedUsed to support: EFSA opinion on hydroxyanthracene derivatives in food. Emodin, aloe-emodin and danthron showed in vitro genotoxicity, aloe-emodin was genotoxic in vivo, and whole-leaf aloe extract and danthron were carcinogenic. The Panel concluded that hydroxyanthracene derivatives should be considered genotoxic and carcinogenic unless specific data show otherwise, and could not set a daily intake free of health concern.
  6. EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA), Turck D, Bohn T, Castenmiller J, De Henauw S, Hirsch-Ernst KI, Knutsen HK, Mangelsdorf I, McArdle HJ, Naska A, Pentieva K, Siani A, Thies F, Tsabouri S, Vinceti M, Rossi A, Titz A, Fiolet T, Maciuk A. Scientific Opinion on additional scientific data related to the safety of preparations of Rheum palmatum L., Rheum officinale Baill. and their hybrids, Rhamnus purshiana DC., Rhamnus frangula L. and Cassia senna L., submitted pursuant to Article 8(4) of Regulation (EC) No 1925/2006. EFSA J. 2024;22(5):e8766. doi: 10.2903/j.efsa.2024.8766.PubMedUsed to support: EFSA review of genotoxicity data submitted during the Union scrutiny of rhubarb, cascara, frangula and senna preparations. All submitted studies were negative, but the preparations were poorly characterized and contained a compound known to be genotoxic in vivo, so the Panel concluded that the safety of frangula bark preparations containing hydroxyanthracene derivatives cannot be established.
  7. Stott C, Graaf L, Morgan P, Kittscha J, Fairbrother G. Randomized controlled trial of laxative use in postcolostomy surgery patients. J Wound Ostomy Continence Nurs. 2012;39(5):524-8. doi: 10.1097/WON.0b013e3182648cc9.PubMedUsed to support: Randomized trial in 45 colostomy patients at 2 Sydney hospitals. A standardized laxative protocol (first line sterculia with frangula bark, Normacol Plus, and liquid paraffin; second line polyethylene glycol) led to fewer episodes of fecal loading on X-ray than ad hoc laxatives (1 versus 7, P = 0.05) and fewer empty stoma bag changes (P = 0.03). Frangula was not tested separately.
  8. Matev M, Chakŭrski I, Stefanov G, Koĭchev A, Angelov I. [Use of an herbal combination with laxative action on duodenal peptic ulcer and gastroduodenitis patients with a concomitant obstipation syndrome]. Vutr Boles. 1981;20(6):48-51..PubMedUsed to support: Uncontrolled Bulgarian report (English abstract read) in 32 patients with duodenal ulcer or gastroduodenitis and constipation given a laxative blend of Rhamnus frangula, Citrus aurantium and Carum carvi. The authors reported daily bowel movements in 90.6% and movements every second day in 9.4%, with no effect on the gastric mucosa or ulcer healing. No control group.
  9. Siegers CP, von Hertzberg-Lottin E, Otte M, Schneider B. Anthranoid laxative abuse--a risk for colorectal cancer? Gut. 1993;34(8):1099-101. doi: 10.1136/gut.34.8.1099.PubMedUsed to support: Retrospective (3,049 patients) and prospective (1,095 patients) endoscopy studies using pseudomelanosis coli as a marker of long-term anthranoid laxative use, naming aloe, cascara, frangula and rheum. Pigmentation was more common in patients with adenomas and, prospectively, with carcinomas, and the authors calculated a relative risk of 3.04 for colorectal cancer. Observational; frangula was not assessed separately. Cited as safety context only, not as a frangula trial.
  10. Nusko G, Schneider B, Schneider I, Wittekind C, Hahn EG. Anthranoid laxative use is not a risk factor for colorectal neoplasia: results of a prospective case control study. Gut. 2000;46(5):651-5. doi: 10.1136/gut.46.5.651.PubMedUsed to support: Prospective case-control study at the University of Erlangen in 202 patients with new colorectal carcinoma, 114 with adenomas and 238 controls having colonoscopy. Anthranoid laxative use was not linked to adenomas (adjusted odds ratio 0.84) or carcinomas (adjusted odds ratio 0.93), and macroscopic or marked microscopic melanosis coli was not a significant risk factor. Covers anthranoid laxatives as a class, not frangula alone.
  11. Willems M, van Buuren HR, de Krijger R. Anthranoid self-medication causing rapid development of melanosis coli. Neth J Med. 2003;61(1):22-4..PubMedUsed to support: Case report of a 39-year-old liver transplant patient who developed melanosis coli within 10 months of taking an over-the-counter product containing aloe, rheum and frangula; the mucosa looked normal 1 year after stopping, but a tubulovillous adenoma was then found. A single case, cited for the pigmentation timeline only.
  12. Brkanac SR, Gerić M, Gajski G, Vujčić V, Garaj-Vrhovac V, Kremer D, Domijan AM. Toxicity and antioxidant capacity of Frangula alnus Mill. bark and its active component emodin. Regul Toxicol Pharmacol. 2015;73(3):923-9. doi: 10.1016/j.yrtph.2015.09.025.PubMedUsed to support: In vitro study in human peripheral blood lymphocytes: frangula bark extract caused cell death and DNA damage at 500 μg/ml, and emodin at 150 and 200 μg/ml, with oxidative stress involved. The extract, unlike emodin, had moderate antioxidant capacity in DPPH, ABTS and FRAP assays (phenolic content 116.07 mg/g). Lab study only.
  13. Vuletić S, Bekić M, Tomić S, Nikolić B, Cvetković S, Ganić T, Mitić-Ćulafić D. Could alder buckthorn (Frangula alnus Mill) be a source of chemotherapeutics effective against hepato- and colorectal carcinoma? An in vitro study. Mutat Res Genet Toxicol Environ Mutagen. 2023;892:503706. doi: 10.1016/j.mrgentox.2023.503706.PubMedUsed to support: In vitro study of a Frangula alnus ethyl acetate extract and emodin in HepG2 and HCT116 cell lines and normal MRC-5 fibroblasts. Both reduced cell viability, caused cell cycle arrest and cell death, and showed strong genotoxic potential in the comet assay in all cell lines, with no notable selectivity. Lab study only.
  14. Kledecka A, Siejak P, Pratap-Singh A, Kowalczewski PŁ, Fathordoobady F, Jarzębski M, Smułek W. Extracts from Frangula alnus Mill. and Their Effects on Environmental and Probiotic Bacteria. Plants (Basel). 2022;11(20):2719. doi: 10.3390/plants11202719.PubMedUsed to support: Laboratory study of frangula bark extracts made with four solvents. Frangulin was confirmed as a main constituent; Pseudomonas fluorescens was particularly sensitive, ethanolic extracts acted most strongly, and the extracts had no direct effect on the tested probiotic Lactobacillus strain. Culture work only.
  15. National Institute of Child Health and Human Development. Buckthorn. Drugs and Lactation Database (LactMed®). 2006;Bethesda (MD): National Institute of Child Health and Human Development; 2006-. Buckthorn entry dated 21 June 2021..PubMedUsed to support: NIH LactMed entry covering European buckthorn, alder buckthorn (Rhamnus frangula) and California buckthorn (Rhamnus purshiana), whose anthraquinones have potent cathartic properties. Maternal intake might cause loose stools in breastfed infants and use should be avoided. Warns not to confuse these products with sea buckthorn (Hippophae rhamnoides).
  16. Peloso M, Capriotti A, Accurso D, Butovskaya E, Fedrizzi G, Caprai E. UPLC-MS/MS Analysis of Hydroxyanthracene Derivatives in Botanical Food Products and Supplements: Surveillance of the Italian Market. Foods. 2025;14(7):1229. doi: 10.3390/foods14071229.PubMedUsed to support: Italian market survey of 43 botanical foods and supplements based on aloe, senna, cassia, rhubarb and frangula. 33% contained hydroxyanthracene derivatives above the limit of quantification; the highest levels, up to 1352.9 mg/kg of aloins and 213.4 mg/kg of aloe-emodin, were in solid supplements made from senna, cascara, rhubarb and frangula. The authors called for stricter market surveillance.