Herb of the Month: Barberry

The Bitter Truth

I’ve been writing a lot about Eastern herbs, it seems – so I wanted to touch on a native British plant for this month’s HOTM. It’s difficult, with so many wonderful herbs out there, to stick to native varieties, but many herbalists do so with great results. There’s also a certain satisfaction that comes with finding natural healing solutions by looking no further than your back garden.

You may have heard of Goldenseal – a wonder herb known to Native Americans before the settlement of America that became such an international phenomenon that it is now endangered in the wild. A powerful anti-bacterial and healing agent, it is traditionally used for various digestive, respiratory, menstrual and skin conditions.

Tiny Goldenseal or Hydrastis canadensis

Tiny little Goldenseal (Hydrastis canadensis)

Thankfully, we have a British plant that is very similar in nature to Goldenseal – the common Barberry or Berberis vulgaris. What makes these two so similar is ‘berberine’, a phytochemical so yellow that most plants containing it have been historically used as dyestuff for fabric, leather, wood and hair. I’ll come back to berberine in a bit – it is a nifty little compound.

Barberry - the fruits can be made into delicious jams and the root and stem bark are used medicinally

Barberry – the fruits can be made into delicious jams and the root and stem bark are used medicinally

However, most importantly to the herbalist is the fact that these two plants are both bitters. Which means they taste really bitter. And the fact that we now live in a society in which it is increasingly difficult to find naturally bitter foods, without added sugar or salt, makes these plants ever more valuable. There are of course some naturally bitter tastes we might encounter – black coffee, rocket, Campari spritzers (if you’re Italian), overcooked cabbage – but on the whole they are few and far between. And why should we be seeking bitter tastes, you might well ask?


When we eat something bitter, it triggers a reflex reaction that travels from our taste buds and the receptors of the upper gastrointestinal tract, through the parasympathetic nervous system, down to the organs of our lower gastrointestinal tract, where it stimulates the secretion of digestive juices. Extra saliva helps digest carboydrates, gastric juices in the stomach help digest protein, and extra bile produced by the liver helps digest fats. This can help prevent things like indigestion, constipation and gallstones from developing.

Bitters have a mild influence on digestive hormones, helping the pancreas secrete insulin and glucagon to deal with glucose metabolism. In low doses they can also increase the strength of the lower oesophageal sphincter, preventing ‘heartburn’ – the reflux of acidic stomach contents into the oesophagus (Mills & Bone, 2013). So the Italians have it right with their obsession for pre-meal ‘aperitivi’ – a spoonful of bitterness does help the huge bowl of pasta go down.


Apart from being multifaceted digestive aids, they are traditionally used to ‘cool’ and ‘nourish’ the body in conditions related to digestive dysfunction or ‘excessive heat’ – headaches, migraines, skin conditions, allergic or hypersensitivity disorders, and menstrual complaints. They are useful to stimulate appetite in the elderly or infirm. And modern research into their anti-bacterial compounds has given us a load of extra reasons to incorporate them into our diet – which is where we come back to Barberry and berberine.

Bacteria: the good, the bad and the…

You may be aware of recent media coverage of ‘good’ and ‘bad’ bacteria and how much of each we should have in our intestines. We don’t know exactly what the ideal situation is, but we do know that populations of each change according to our age, the food we eat and the lifestyles we lead, and that ‘bad’ bacteria contribute to a whole host of diseases; food intolerances, irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), asthma, psoriasis and autoimmune conditions such as rheumatoid arthritis.

As for berberine, not only do we know that it is a powerful anti-microbial against several bacterial species, but one study has shown that it might selectively inhibit the growth of harmful gut bacteria while sparing the good, probiotic bacteria. Traditionally, the herb Barberry plays an important part in correcting ‘intestinal dysbiosis’ – the dysfunction of intestinal bacteria that can lead to so many problems.

Even more fascinating is a study that uncovered a hidden mechanism behind berberine’s anti-bacterial effects. The researchers identified compounds in the leaves of several Berberis species that were helping berberine kill bacteria. They were doing this by disabling the resistance mechanisms of the bacteria, making it easier for berberine to get inside and do its job. This is a great example of synergy in herbal medicine and may be why the tincture of Barberry was found in one study to be a more effective anti-microbial than pure berberine.

Showing 5-MRC helping berberine overcome the bacterium's defence pump

Showing how 5′-MHC helps berberine overcome the bacterium’s defence pump

However, unfortunately, all the clinical trials have been conducted on berberine alone, so little scientific evidence exists for Barberry itself or, for that matter, Goldenseal. And, alas, all the trials used a much higher dose of berberine found in an average dose of these herbs. Even so, I wanted to highlight a selection of these trials just FYI.

Diabetes mellitus

In a randomized, double blind, placebo-controlled trial of 116 type 2 diabetic patients, berberine at 1000mg/day for 3 months reduced body weight, blood pressure, blood glucose levels, cholesterol, triglycerides, liver enzymes and inflammatory markers more than placebo and lower than baseline (the level at which patients started the study). Five patients complained of constipation, which was the only side effect.

In another trial comparing berberine to conventional drugs metformin (also from a plant!) and rosiglitazone in 97 patients for 2 months, the authors concluded that it is almost as effective as these first-line drugs, acting by increasing insulin receptors on cells. Due to the fact that the conventional drugs can cause liver damage, another study was included in the publication showing that berberine also lowered elevated liver enzymes in patients with liver disease AND type 2 diabetes.

There are many smaller studies investigating berberine and diabetes, and results tend to be in line with the traditional indication of bitters in disorders of glucose metabolism.


In 51 patients treated for 8 weeks with eyedrops containing either 0.2% berberine chloride or 20% sulfacetamide (an anti-trachoma drug), the latter gave the best results but initially but then relapses occurred. Berberine patients remained free of the infectious agent. An anti-microbial eyewash can be made at home for any irritated or infected conditions of the eye simply by diluting a few drops of Barberry tincture in water and dabbing on the eye.


In an old Indian trial, berberine was given at a dose of 5mg/day to 25 children with giardiasis for 6 days – Giardia cysts were eliminated in 68%, compared with 25% for placebo and 100% for metronidazole (an antibiotic). In another study of 42 children however, 90% were negative for the cysts after 10 days of berberine treatment – although some relapsed a month later. Traditionally however, stronger bitters such as Wormwood (Artemisia annua or absinthium) and Gentian (Gentiana lutea) are given for parasitic conditions like Giardia.

Back to bitters

Meanwhile, the use of Barberry by herbalists is more centred on traditional indications of bitter herbs than any modern clinical trials, especially since whole herbs are not tested as regularly as their individual components. Incorporate some bitterness into your diet, however, and you will feel the difference. The taste gets better with time and some would argue it develops and richens your taste buds. You begin to notice other things under the bitterness – the smokey and fruity notes of a good strong espresso, for instance. Try dark chocolate (85% and above), fresh dandelion leaf salad (in the spring, of course), and cutting out sugar/honey from tea and coffee.

Recently harvested dandelion plants

Recently harvested dandelion plants

As for Goldenseal, its mucosal healing properties in chronic sinusitis, allergic rhinitis (hayfever) and the late stage of the common cold are unparalleled even by Barberry. In most other cases it can be substituted, but if you need an anti-catarrhal remedy that also restores structure to damaged mucous membranes (and you can afford it), Goldenseal is the best. For congested sinuses, a topical sinus rub made from equal parts Goldenseal, Myrrh, Cayenne pepper and Lobelia really does the trick. I’ll be making one when my Goldenseal arrives next week!


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s