Uva Ursi (Arctostaphylos uva-ursi): Benefits, Dosage, Safety & Evidence

Questions fréquentes

How does uva ursi work for urinary tract infections?

Uva ursi contains arbutin, which converts to hydroquinone in alkaline urine, creating an antiseptic effect directly in the urinary tract. This antimicrobial action targets bacteria responsible for urinary tract infections. The herb also contains tannins that provide astringent effects, helping reduce inflammation in urinary tissues. For optimal effectiveness, urine should be alkaline, as hydroquinone formation requires a higher pH. Evidence Level: C (limited clinical trials).

Can you take uva ursi while pregnant or breastfeeding?

Uva ursi is considered unsafe during pregnancy and breastfeeding. The hydroquinone compounds can cross the placenta and may harm fetal development. These compounds may also pass into breast milk, potentially affecting nursing infants. Pregnant or breastfeeding individuals should avoid uva ursi entirely and consult healthcare providers for safer alternatives for urinary tract support. Evidence Level: Traditional/C (contraindicated based on theoretical risks).

What is the recommended dosage of uva ursi for UTIs?

The typical adult dosage of uva ursi is 400-800mg of standardized extract (containing 20% arbutin) taken three times daily. Treatment should not exceed one week due to hydroquinone toxicity risks with prolonged use. Dried herb preparations may require higher doses. Uva ursi is not recommended for children under 12. Always follow product labeling or consult a qualified herbalist for personalized dosing. Evidence Level: C.

Does uva ursi interact with any medications?

Uva ursi may interact with medications that acidify urine, such as cranberry supplements or high-dose vitamin C, as these can reduce its effectiveness by preventing hydroquinone conversion. It may also interact with diuretics, potentially increasing fluid loss. Due to potential liver effects with chronic use, combining uva ursi with hepatotoxic medications should be avoided. Always consult a healthcare provider before combining with prescription medications. Evidence Level: Traditional/C.

How long can you safely take uva ursi?

Uva ursi should not be taken for more than one week continuously due to hydroquinone toxicity risks. Chronic use can cause liver damage and other serious side effects. A minimum break of 1-2 weeks between treatment courses is recommended. Long-term use may also lead to green-brown urine discoloration, nausea, and gastrointestinal upset. Consult a healthcare provider if symptoms persist beyond the recommended treatment period. Evidence Level: C/Traditional.

Fiche d'information compilée à partir de PubMed

Cette fiche a été compilée à partir de résumés PubMed (NIH) avec l'assistance d'une IA. Chaque affirmation factuelle est citée par un article PubMed réel (voir la liste des sources). Elle n'a pas encore été révisée par un humain — confirmez auprès d'un professionnel de santé avant utilisation.

Compilé à partir de 28 articles PubMed · modèle : gemma4:31b

Résumé

Uva ursi (Arctostaphylos uva-ursi) is an herbal extract derived from the leaves of a small evergreen shrub, primarily used as a urinary antiseptic [PMID:30000963].

Contexte

Uva ursi, also known as bearberry, is a procumbent evergreen shrub found throughout North America, Asia, and Europe [PMID:27043639]. It is a source of herbal material (Uvae ursi folium) highly valued by the pharmaceutical and cosmetic industries [PMID:34946773].

Usages traditionnels

It has been used in Native American traditional medicine for the treatment of urinary tract symptoms and as a diuretic [PMID:30000963]. It has also been used in folk medicine for centuries as an antimicrobial and anti-inflammatory agent for various urogenital tract diseases [PMID:34946773].

Composés actifs

The leaves are dominated by arbutin (a phenol glucoside), which is hydrolyzed to hydroquinone [PMID:30000963, PMID:32495959]. Other constituents include saponins, phenolic carboxylic acids (such as gallic acid), flavonoids, hydroxycinnamic acids, and various hydrolyzable tannins [PMID:35953755, PMID:34493038].

Mécanisme d'action

The antiseptic and diuretic properties are attributed to hydroquinone, which is obtained via the hydrolysis of arbutin [PMID:35143933]. Arbutin may also alleviate fatty liver by inhibiting ferroptosis via the FTO/SLC7A11 pathway [PMID:30000963] and regulate pathological processes in intestinal colitis by modulating neutrophil extracellular traps formation and microbiota composition [PMID:38772182].

Preuves cliniques

Preuve BUncomplicated Urinary Tract Infection (UTI)

A double-blind RCT compared uva ursi (105 mg 3x/day for 5 days) against fosfomycin (3g single dose) to evaluate antibiotic use and symptom burden [PMID:34111592].

Preuve DUrolithiasis (Kidney Stones)

In female Wistar rats, herb infusions showed beneficial effects attributed to disinfectant action and potentially saponins, with some solvent action against uric stones due to basifying capacity [PMID:7860196].

Preuve DUlcerative Colitis

In a mouse model of DSS-induced colitis, oral administration of β-arbutin (50 and 100 mg/kg) was investigated for its curative effect on disease activity index, colon length, and histopathology [PMID:38772182].

Preuve DInsulin Resistance

Dry alcohol extract from bearberry leaves, enriched with cysteine, was studied for hypoglycemic and pancreatic protective effects in rats with dexamethasone-induced insulin resistance [PMID:35953755].

Sécurité et effets indésirables

Lengthy exposure to free hydroquinone is associated with toxicity in different organs [PMID:32495959]. However, treatment with uva ursi extracts has not been specifically linked to clinically apparent acute liver injury or serum aminotransferase elevations [PMID:30000963]. A therapeutic daily dose of 420 mg hydroquinone derivatives (as anhydrous arbutin) results in a maximum free hydroquinone exposure in urine of 11 µg/kg body weight/d [PMID:24296864].

Grossesse et allaitement

Uva ursi should generally be avoided during breastfeeding due to a lack of safety and efficacy data in nursing mothers or infants and its potential toxicity [PMID:30000963].

Interactions médicamenteuses

Uva-ursi extracts showed the strongest inhibitory effect on UGT1A1-mediated β-estradiol 3-glucuronidation, with gallotannin and 1,2,3,6-tetragalloylglucose identified as potent inhibitors of UGT1A1 [PMID:30075316].

Synthèse des preuves

Evidence is primarily based on in vitro studies, animal models (D), and a few clinical trials (B). While traditionally used for UTIs, high-quality clinical evidence comparing it to standard antibiotics is limited.

Sources PubMed

1.PMID: 30000963 (2006) — Arbutin alleviates fatty liver by inhibiting ferroptosis via FTO/SLC7A11 pathway. · Redox biology
2.PMID: 36445447 (2023) — [Phytotherapy in uro-oncology]. · Urologie (Heidelberg, Germany)
3.PMID: 38772182 (2024) — Arbutin alleviates intestinal colitis by regulating neutrophil extracellular traps formation and microbiota composition. · Phytomedicine : international journal of phytotherapy and phytopharmacology
4.PMID: 7860196 (1994) — Urolithiasis and phytotherapy. · International urology and nephrology
5.PMID: 24296864 (2013) — Risk assessment of free hydroquinone derived from Arctostaphylos Uva-ursi folium herbal preparations. · International journal of toxicology

Uva Ursi

Sources et citations

Calculer une dose sûre de Uva Ursi

Cranberry

Questions fréquentes

Résumé

Contexte

Usages traditionnels

Composés actifs

Mécanisme d'action

Preuves cliniques

Sécurité et effets indésirables

Grossesse et allaitement

Interactions médicamenteuses

Synthèse des preuves

Sources PubMed

Sources gouvernementales

Uva Ursi

Sources et citations

Calculer une dose sûre de Uva Ursi

Plantes associées

Cranberry

Questions fréquentes

Résumé

Contexte

Usages traditionnels

Composés actifs

Mécanisme d'action

Preuves cliniques

Sécurité et effets indésirables

Grossesse et allaitement

Interactions médicamenteuses

Synthèse des preuves

Sources PubMed

Sources gouvernementales