Uva Ursi (Arctostaphylos uva-ursi)

Uva ursi is consumed as a medicinal herbal preparation (leaf tea, extract, or capsule), not as a food, so traditional macronutrient profiling (calories, protein, fat, carbohydrates) is not applicable at typical therapeutic doses. Key bioactive compounds include: • Arbutin (hydroquinone-β-D-glucopyranoside): 5–15% of dried leaf weight (primary active constituent); undergoes hydrolysis in alkaline urine to release hydroquinone, the antimicrobial metabolite. Standardized extracts typically deliver 100–210 mg arbutin per dose (equivalent to ~400–800 mg arbutin per day in divided doses). Bioavailability: arbutin is well absorbed orally and metabolized via gut microbiota and hepatic conjugation; urinary hydroquinone release is pH-dependent (optimal at urine pH >8). • Free hydroquinone: 0.1–0.5% of dried leaf; contributes directly to antimicrobial activity but also to hepatotoxicity concerns at high doses. • Tannins (gallotannins and ellagitannins): 15–20% of dried leaf weight, including corilagin, gallic acid, and ellagic acid; responsible for astringent properties and may contribute to anti-inflammatory and antidiarrheal effects. High tannin content may reduce bioavailability of co-ingested nutrients and medications. • Flavonoids: including hyperoside (quercetin-3-O-galactoside, ~0.5–1%), isoquercitrin, myricetin glycosides, and myricitrin; contribute antioxidant and mild anti-inflammatory activity. • Iridoid glycosides: including monotropein (trace to ~0.5%). • Triterpenes: ursolic acid (~0.4–0.8%) and oleanolic acid; associated with anti-inflammatory and hepatoprotective properties in preclinical models. • Phenolic acids: including gallic acid (~1–2%), p-coumaric acid, and syringic acid. • Allantoin: trace amounts; traditionally associated with tissue-soothing properties. • Minerals: Leaf material contains modest amounts of calcium, potassium, magnesium, and manganese typical of woody shrub foliage, but quantities delivered at therapeutic doses (1.5–4 g dried leaf/day) are nutritionally negligible. • Vitamins: No significant vitamin content at medicinal doses. • Fiber: Dried leaf contains insoluble plant fiber, but amounts consumed medicinally are too small to be dietarily relevant. Bioavailability notes: Arbutin absorption is rapid (Tmax ~1–2 hours); however, antimicrobial efficacy depends on urinary alkalinization (traditionally achieved by co-administration of sodium bicarbonate or alkaline diet). Tannin content may cause gastrointestinal irritation and reduce absorption of iron, alkaloids, and certain medications if co-administered. Prolonged use (>1–2 weeks) or high doses risk cumulative hydroquinone toxicity (hepatotoxicity, nephrotoxicity). The European Medicines Agency (EMA) recommends limiting use to 1 week and no more than 4 treatment episodes per year.