Also known as: Barberry, Common Barberry,  Jaundice Berry, Mountain Grape, Oregon Grape,  Sow Berry, 
CAUTION: See separate listing for Oregon Grape. Berberis aquifolium

Scientific name: Berberis vulgaris

Family: Berberidaceae.

Traditiona Uses: Orally, the fruit of European barberry is used for kidney, urinary tract, and gastrointestinal tract discomforts such as heartburn, stomach cramps, constipation, lack of appetite, liver and spleen disease, for bronchial and lung discomforts, spasms, as a stimulant for circulation, for people susceptible to infection, and as a supplemental source of vitamin C. The bark, root, and root bark of European barberry are also used orally for ailments and complaints of the GI tract, liver, gallbladder, kidney and urinary tract, respiratory tract, heart and circulatory system, to lower a fever, "blood purifier", and for narcotic withdrawal. European barberry root bark is used for liver dysfunction, gallbladder disease, jaundice, splenopathy, diarrhea, indigestion, hemorrhoids, renal and urinary tract diseases, gout, rheumatism, arthritis, mid and low back pain, malaria, and leishmaniasis.
In foods, European barberry fruit is used in making jam, jellies, and wine.
In manufacturing, the fruit syrup is used for masking tastes in pharmaceutical preparations.

Safety:

Traditionally used as a fruit syrup and preserve.when the fruit is consumed orally in food amounts
There is insufficient reliable information available about the safety of European barberry when used in medicinal amounts.
Avoid use in infants especially newborns Avoid use in pregnancy unless advised by a qualified medical herbalist. Particularly avoid in the last triimester of pregnancy.

Avoid in breastfeeding especially newborns.

Evidence from Scientific Research

Very little clinical research has been done.

Dental Plaque: Preliminary clinical research suggests that brushing with a European barberry extract gel containing 1% berberine three times daily for 3 weeks significantly reduces plaque index compared to placebo and has similar effects compared to a commercial antiplaque toothpaste (Colgate)

Diabetes. Small studies suggests that taking European barberry for 8 weeks does not affect blood sugar control in patients with type 2 diabetes
Gum disease: Preliminary clinical research suggests that brushing with a European barberry extract gel containing 1% berberine three times daily for 3 weeks significantly reduces gingival index compared to placebo

How might it work:

The applicable parts of European barberry are the fruit (berry), root, bark, and root bark. Preliminary research suggests that European barberry fruit has antihistaminic and anticholinergic effects
Other preliminary research suggests European barberry fruit has hypotensive effects. It might also reduce neural cell excitability
European barberry root also seems to have anti-inflammatory activity, which is possibly mediated by its alkaloid constituents such as berberine
The primary active constituent of European barberry is berberine Berberine has antihypertensive, inotropic, and antiarrhythmic properties. Berberine appears to have alpha-adrenergic blocking activity. Preliminary clinical research suggests that berberine might reduce arrhythmias and improve left ventricular function in patients with heart failure Preliminary research suggests that berberine might also lower blood glucose and low-density lipoprotein (LDL) cholesterol. Berberine might also inhibit aldose reductase
Other preliminary research suggests berberine might have antitumor effects and might protect the liver from hepatotoxins
Berberine has antimicrobial effects including antibacterial, antifungal, and some antimycobacterial and antiprotozoal activity. Berberine has activity against Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli, Shigella boydii, Vibrio cholerae, Mycobacterium tuberculosis, Candida albicans, Candida tropicalis, Trichophyton mentagrophytes, Microsporum gypseum, Cryptococcus neoformans, Sporotrichum schenckii, Entamoeba histolytica, and Giardia lamblia.

Preliminary research suggests berberine might inhibit bacterial sortase, a protein responsible for anchoring gram-positive bacteria to cell membranes. Preliminary clinical research suggests it might be useful for topical treatment of burns and trachoma, a common cause of blindness in developing countries.
Preliminary research suggests that berberine blocks production of the proinflammatory cytokines interleukin-1 (IL1)-beta and tumor necrosis factor (TNF)-alpha by blocking nuclear factor-kappaB, the transcription factor responsible for regulation of cytokine production. Berberine has potential usefulness in treating alcoholic liver disease, which is associated with increased levels of IL1-beta and TNF-alpha.
Preliminary research suggests berberine selectively inhibits cyclooxygenase (COX)-2 expression. Berberine appears to reduce the secretion of gastric acid.
Whether European barberry has the same clinical effects as berberine is unknown.
Berberine appears to undergo phase I hepatic metabolism. It also appears to be a substrate of nuclear transporters such as P-glycoprotein and organic cation transporter. Theoretically, this might limit its oral bioavailability.

Unwanted effects:

Orally, the use of European barberry and other berberine-containing herbs during pregnancy, lactation, or in newborn infants can cause jaundice as the infant have not yet the capacity to metabolise berberine.

No adverse reactions have been reported for berberis vulgaris and no clinical studies have been done. In traditional use it is well tolerated.

Berberine, a primary constituent of European barberry, has been used orally in adults in doses up to 2 grams/day for 8 weeks with no adverse effects reported
Topically, berberine has been used for up to 20 days with no adverse effects reported.

Interactions with drugs/supplements:

Anticoagulants/antiplatelet drugs: No reported cases of blood clotting problems have been reported with this herb. However Berberine, one of the many constituents of European barberry, may inhibit platelet aggregation in animal studies so caution is advised.

Blood sugar control: Clinical study demonstrated no blood sugar lowering effect, but advise monitoring for diabetics as theoretically a lowering of blood sugar is possible.

Lowering Blood Pressure: Theoreticall an effect of lowering blood pressure may add to the therapeutic effect of medication, as a precaution remain seated or lie down for 30 minutes after the first 2-3 doses and monitor effect.

Transplant antirejection Cyclosporin A (CsA): The constituent Berberine can markedly elevate the blood concentration of CsA in renal-transplant recipients in both clinical and pharmacokinetic studies. This combination may allow a reduction of the CsA dosage. The mechanism for this interaction is most likely explained by inhibition of cytochrome CYP3A4 in the liver and/or small intestine.

CYP3A4 Metabolised Drugs: Theoretically blood levels can be elevated or lowered. Common drugs include the SSRI antidepressants, Some Statins (lovastatin), some antibiotics,  for full list see http://www.pharmacytimes.com/publications/issue/2008/2008-09/2008-09-8687

Effect on lab. tests:

Theoretically, European barberry might increase bilirubin levels. This has been demonstrated with isolated berberine constituent, but not specifically with European barberry. Berberine displaces bilirubin from albumin and increases total and unbound bilirubin concentrations.

Effect on conditions or disorders:

BLEEDING DISORDERS: Berberine, a constituent of European barberry, might inhibit platelet aggregation. Theoretically, European barberry might increase the risk of bleeding and interfere with therapy in patients with bleeding conditions. 
DIABETES: Berberine, a constituent of European barberry, may have hypoglycemic effects. However, preliminary clinical evidence suggests that European barberry does not affect glucose levels in patients with type 2 diabetes. Until more is known, use cautiously in patients with diabetes, as European barberry may increase the risk for hypoglycemia in patients on insulin or oral hypoglycemic medications. Monitor blood glucose levels. 
HYPOTENSION: European barberry extracts might have hypotensive effects Theoretically, European barberry might increase the risk of hypotension in people with low blood pressure. Advise hypotensive patients to use European barberry with caution. 
SURGERY: Berberine, a constituent of European barberry, might inhibit platelet aggregation, have sedative effects, and lower blood glucose. Theoretically, European barberry might cause excessive bleeding and/or additive CNS depression, or interfere with blood sugar control, when used perioperatively. Tell patients to discontinue European barberry at least 2 weeks before elective surgical procedures.

Dose:

ORAL: No typical dosage. Traditionally, a typical dose is one cup tea. To make tea, steep 1-2 teaspoons of whole or squashed berries in 150 mL boiling water 10-15 minutes and strain or steep 2 grams of root bark in 250 mL boiling water 5-10 minutes and strain. Root bark is typically used as a tincture (1:10), 20-40 drops per day.