How Uva Ursi or Bearberry Benefits Were Found?
Since 13 century, Uva ursi or bearberry leaves use as a herbal remedy for many ailments. In the Welsh “Physicians of Nyddfai,” Uva ursi had first recognized literally in the Middle Ages.  After that many literature sources have found which documented traditional uses of uva ursi leaf. The German Federal Institute for Drugs and Medical Devices has approved this herbal ingredient for urinary tract inflammatory conditions. In Germany, Uva ursi is recommended as prescribed medication and available in pharmacy stores. However, in the UK, this herbal medicine is widely available as an OTC product to relieve acute UTI.  There are multiple health benefits of Uva ursi have documented including:
·Urinary antiseptic used to treat moderate inflammatory conditions of the urinary tract and bladder, such as cystitis, urethritis, pyelitis, Lithuania, acute catarrhal cystitis with highly acidic urine, and dysuria.
·Other traditional uses of Uva ursi include a diuretic, anti-inflammatory properties, renal or urinary stone, poor eyesight, diabetes, rheumatism, and venereal disease.
·This leaf extract has astringent and topical applications of this herbal preparation can treat skin depigmentation.
What Are The Phytochemicals Present in Uva Ursi or Bearberry?
Phytochemicals obtain from the Uva ursi plant include iridoids, flavonoids, hydroquinone glycosides, terpenoids, and tannins. Arbutin, which is a primary hydroquinone glycosides present in Uva ursi has potent antimicrobial properties. 
What is the Mode of Action of Uva Ursi or Bearberry Health Benefits?
An in-vitro trial of uva ursi reported that this herbal remedy has potent antimicrobial effect against many microorganisms including Escherichia coli, which is one of the primary causative organisms of the urinary pathogen.
Arbutin and hydroquinone are the phytochemicals that have a growth inhibitory effect against microorganisms, such as Mycoplasma hominins and Ureaplasma urealyticum. Intake of the leaves containing Uva cruise preparation leads to the absorption of arbutin in the gastrointestinal tract, which is further hydrolyzed by the gut microbiome and form aglycone, hydroquinone. Hydroquinone is further metabolized to form glucuronate and sulfate esters, which are then excreted with urine. These bioactive metabolic products have an antiseptic and astringent effect on the urinary mucous membranes in the alkaline urinary medium. The Theirantibacterial effect reaches in its peak after 3-4 hours of ingestion.
What Are the Different Forms of Uva Ursi or Bearberry?
There different dosage forms of Uva ursi are available in herbal medicinal shops, which include herbal tea, different types of the dry extract obtained by using different solvents, powdered herbal substance, liquid extract, tincture, decoction and solid dosage form like capsule contains dried herbal substance, etc. 
UVA URSI or Bearberry Uses:
Following are some medicinal uses of Uva ursi:
There are much evidence supported that Uva ursi has a potent anti-microbial property. However, this effect depends upon the formulation prepared by using different extraction medium. A 30% ethanolic extract of this herbal formulation has a potent antibacterial effect against Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Salmonella typhimurium, Pseudomonas aeruginosa, and Serratia marcescens. However, such an effect is absent in 95% ethanol or chloroform extracts of this herb. 
A clinical trial conducted in 309 women to check the efficacy of uva-ursi in recurrent urinary tract infection. Uvacin an OTC product containing uva-ursi was recommended to the study participants who had experienced shorter illness duration. The study result showed ingestion of this recommended medication is effective for women with recurrent UTI. Researchers also expected this herbal remedy has a prophylactic effect against urinary tract infection.
A broad antimicrobial effect of Uva ursi leaves is effective to control different bacterial infections including Streptococcus mutans, Escherichia coli, Proteus Vulgaris, Streptococcus faecalis and Enterobacter aerogenes by inhibiting their growth. All these antibacterial effects have checked through in vitro studies and identified arbutin is a primary antibacterial phytochemical present in this herb. A research study result also reported that the urine sample collected after 3 hours of arbutin administration showed strong antibacterial activity against 20 bacterial strains. 
The leaves of this plant have antiviral activity also against many viral infections with a particular concentration of 10% extract. Uva ursi leaves is effective against herpes simplex virus type 2, influenza virus A2 and vaccinia viral infections. 
Urinary tract infection
Uva ursi leaves extract is considered as the treatment of UTI infection. A double-blind clinical trial result reported that combination with ibuprofen or other NSAIDs medicine along with Uva ursi is effective to the relief of the distressing symptoms of UTI in women due to its antibacterial properties against. coliis effective to control infection. 
Oral ingestion of the methanolic extract of Uva ursi leaves has anti-inflammatory properties. Animal research confirms the inflammation controlling effect of this plant and reported the anti-inflammatory effect of Uva ursi is comparable with steroidal drugs like prednisolone and dexamethasone.
Arbutin is effective as codeine in cough suppression. An animal research study confirms the administration of this active ingredient acts as an antitussive and effective to suppress cough triggers induced by nylon fibers.
Effect on skin depigmentation
Uva ursi leaves extract used in cosmetic formulations due to its skin lightening effect. Hydroquinone and its derivatives present in Uva ursi leaves extract is effective skin depigmentation. 
Uva Ursi or bearberry Side effects
Uva ursi administration is not recommended for long-term applications due to the presence of hydroquinone can cause liver toxicity, carcinogenic effect, and irritant.However, a risk assessment research review result reported that no direct evidence has found from the human trial report which supports that the free hydroquinone leads to hepatotoxicity, convulsion, nephrotoxicity, or tumors progression in humans. Free hydroquinone does not cause pancreatic, bladder, stomach, or liver carcinogenesis. Therefore, Uva-ursi folium is a safe therapeutic option to treat lower urinary tract infections.
But to precautionary measures, it is always better than persistent urinary tract infection should be treated after consultation with a doctor instead of taking OTC Uva ursi products. Uva ursi intake can cause greenish-brown urination, which turns to darken in color due to the presence of hydroquinone. 
Increase the level of tannin in Uva ursi can cause stomach irritation, which may produce nausea and vomiting symptoms. The skin lightening effect of Uva ursi occurs at higher concentration but the presence of hydroquinone produces side effects including leukoderma, ochronosis, erythema, and allergic contact dermatitis at different concentration. 
When Should I Avoid UVA URSI or Bearberry?
Children below 12 years of age, pregnant women and lactating mothers should avoid Uva ursi due to lack of safety data. Uva ursi is contraindicated for individuals having kidney disorders. Uva ursi formulation should not intake with acidic foods and medicines. 
1. Assessment report on Arctostaphylos uva-ursi (L.) Spreng., folium. European Medicines Agency
2. Uva-ursi extract and ibuprofen as alternative treatments of adult female urinary tract infection (ATAFUTI): study protocol for a randomized controlled trial
3. Folium Uvae Ursi
4. Uva Ursi
5. Risk assessment of free hydroquinone derived from Arctostaphylos Uva-ursi folium herbal preparations