In response to queries from my students, as well as members of various groups I frequent, today I am starting a series on that all-important foundation of the herbalist’s toolkit; understanding herbal actions. A few entries back I discussed the difference between using herbs in a home-remedy kind of fashion – perfectly good and wonderful – and going deeper, exploring plant medicine with regard to treating people and animals, and therefore learning about basic plant chemistry (constituents) energetics and actions, preparations and dosage, and more. This is, truly, a lifetime of study – but to start, anyone studying herbs will want to be very well acquainted with at least a core group of actions. Simply put, the term “actions” refers to the effect of the herb on the body; what it does, how herbs affect us. Herbal actions can be classified more precisely – as biochemical, empirical, vitalist – for the purposes of this series, actions are simply descriptors of the ways in which herbs act in and affect the body. Many terms are self-explanatory, or popularly used enough as to give the newcomer a general idea as to what they do; others are vague, quaint or obscure. I’m terribly fond of the quaint and obscure, but that’s not especially helpful to those trying to learn. So, in this series I will talk a bit about actions we might be working with a lot, initially- and explore several of the most important, basic terms.
I hope it will be a helpful augment to my students, and of interest to my general readers too of course.
So, let’s start with the term astringent. I chose this one to begin with for two reasons; first, pretty much everyone has some idea what it means. Most people can bring to mind the sensation left on the tongue after a dry red wine, or cup of plain tea; others might think of the effect of witch hazel on the skin. Both tea (Camellia sinensis) and witch hazel (Hamamelis virginiana ) are astringent herbs, rich in tannins, and used in most households – well, perhaps not witch hazel as much as tea! but pretty wellknown all the same. Both of these plants offer straight-up, unmistakable ASTRINGENCY: You drink black tea, your tongue feels dry and puckered; you wipe a cotton ball with witch hazel over your face, and the skin will typically feel dry, even tightened past the point of comfort. That’s astringency! It’s an action many associate, and understandably so, with a drying, tightening effect. Speaking from the point of immediate observation, that’s correct; as we look a little deeper, we’ll see that “drying” is not so accurate – or perhaps more precisely, it’s only part of the story.
The other reason I wanted to start the series with astringency, is practical; so many conditions in dogs and cats, that we might think about treating at home with herbs, call for an astringent herb. These include UTI (urinary tract infection) diarrhea ( with all the many causes for that one) various skin problems (and our animals are so prone to those) swelling and inflammation in the mouth (gingivitis) and respiratory infection, viral or bacterial. These groups do not represent the only uses for astringent herbs, but they are the most common and easy to get started with; after we define the action a bit more, we’ll look at which specific herbs to work with, and how to apply/administer them.
Witch hazel in bloom
So to start with, what do astringents do? Essentially, they tighten and strengthen tissue, contracting and toning to help restore normal function, keep pathogens out, keep fluids in, and reduce inflammation.. This is incredibly useful wherever there is boggy, overly porous tissue, as in damp and cold lung infections or intestinal hyperpermeability; a stronger barrier is always an aid to healing – in part, because a stronger barrier holds fluid in more effectively. And here is the apparent contradiction I alluded to earlier – when you tonify and strengthen tissue,you are doing the opposite of drying. The sensation or appearance of drying is superficial; internally, the whole body is brought back into balance as fluid is retained more effectively. It’s certainly true that overuse of astringents without a balancing demulcent herb may have a drying and undesirable effect on surface tissue, over time. But for starters, let’s think of astringents as using a tightening action to help surfaces to function optimally. Surface contraction is the means to an end, the result should be tissue brought back to balance, not tightened and dried excessively.
This quote from Michigan herbalist Jim MacDonald says it beautifully:
“Astringents are considered drying. This is both a correct and misleading way to understand what they do. Astringent herbs don’t really cause the loss of fluids from the body… in fact, they often are used to help retain fluid from being lost (for example, blackberry root being used to stop diarrhea, shepherd’s purse to staunch uterine bleeding, or staghorn sumach to help resolve excessive urination). ……. What astringents do is restore tone to tissues by causing them to constrict. It is this constriction – generally of the outer surface of the tissues – causes dryness…… In most cases, short term use of astringents causes a localized dryness, while helping to preserve fluids constitutionally. Prolonged use, however, or the use of very strong astringents can constrict tissues too much (and not just on the surface), and in doing so impairs their proper function by both robbing them of fluids and impairing their ability to absorb or secrete fluids ”
It follows that the stronger the astringency, the longer the duration of use, the greater risk of creating a different kind of problem – eg, the hyperpermeable gut is now constricted to the point that nutrients we actually want to pass through, are impaired- affecting overall nutritional status(for example). As with all herbal actions, the application of astringents can be quite straightforward – a tea bag on a hot spot, a gargle with sage tea – or much more nuanced. When working with new ideas and plants – start safe and slow.
Which conditions, then, call for herbs with an astringent action?
A few common animal ailments that call out for astringent herbs for include:
1) gum infection or any scenario where there is puffy, boggy gum tissue; gingivitis
2) kennel cough
3) feline respiratory disease
4) UTI, canine or feline
5) chronic intestinal issues, including food intolerance, IBD and SIBO, any form of “colitis”
6) hot spots, general pruritis, minor infections and abscesses; wound healing
All of the above call for a range of actions, including astringency. There are other applications; I use herbal astringents in my work with cancer, specifically hemangiosarcoma, ; some I use regularly include Butcher’s broom ( uscus aculeatus) Horse Chestnut (Aesculus hippocastanum) Labrador tea (Ledum groenlandicum) Self -Heal (Prunella vulgaris) Shepherd’s purse (Capsella bursis) specifically hemangiosarcoma, but this is advanced work and I will cover much more of it in my thesis, whenever it finally gets done and published. Just by way of mentioning that many herbs have powerful medicinal effects internally, and may help prolong survival time with some cancers. Astringents also possess styptic actions, some more abundantly than others, meaning they can help slow or stop bleeding, internally or externally. Yarrow and blackberry root powder are my own first-aid favorites, I am never without them around the house or in my help-bag.
The humble and ubiquitous Shepherd’s Purse, combined with Yarrow and other herbs, can stop internal bleeding as powerfully, or moreso ,than the very popular vet-prescribed Yunnan Baiyao.
Which plants are useful astringents and how do we decide what to select and use?
I would recommend using a process based on three factors; strength of astringency (that’s the tough one, because while some plants clearly have strong/mild action, in the middle there is a range, and can depend on other factors such as how prepared) secondary actions, and organ/system affinity. Let’s look at these three factors and see how they help us make a selection.
1) Strength of action: astringent herbs may be mild, moderate or strong. Sometimes, as with severe diarrhea we want to stop asap, strong action is required (I prefer blackberry to elm in this case)..other times, as with sensitive dry skin, we might prefer to treat a hot spot with milder astringency. One good way to know the strength of your herbs is just to work with them. Everything I have listed is pretty much readily available, you can purchase the whole herb and start experimenting. Make a quarter cup of infusion with plantain, one with raspberry, another with sage, blackberry, goldenrod…steep them all the same length of time, and taste. Or just taste the plant! I’ve listed a few of my favorites below. Of course, how one prepares an herb can increase or decrease potency, this category refers to the basic strength within the plant itself.
2) Secondary actions, or in other words, what else does the plant do? Some have anti-microbial action, important for infection; others are also demulcent (slimy and soothing) good for balancing astringent’s superficial drying effect; others may be diuretic, expectorant, anti-spasmodic ..and so on. We always have to consider the whole spectrum of actions when deciding on any herb to use. This is where developing deep knowledge about a few herbs at a time is helpful – you won’t need to look everything up when considering which plant to reach for. Of course, a good herbal with a Materia Medica listing all properties (and contraindications) of each plant is essential. None of us remember everything all the time – when in doubt, check!
3) Organ/system affinity: does the astringent you am considering have a particular affinity for the part of the body you seek to support? Ideally, we find a herb that does it all – say you are looking to clear up a mild urinary tract infection. Uva ursi (arctostapholys uva-ursi), is astringent, antibacterial, diuretic and has affinity for the urinary tract, so it will be an obvious choice. I’ve listed a few affinities below; one can also work with a formula and include other herbs that direct the action to the desired part of the body, and the more complex the problem the likelier it is you will want to formulate anyway, to include other actions. I mention system-affinity here as another part of the picture you need to keep in mind when selecting which to use, but you can always work with what you have, once you have more fluency with herbs. This is more about how to think like a herbalist than to encourage slavish adherence to a set of rules. :)
Of course, everyone needs a basic repertoire of herbs from each category of action – there is no substitute for practical use! Some of my own favorite astringents (for use with dogs, cats,and humans!) are as follows:
Plantain (Plantago major, lanceolata) Parts used: Leaves, preferably fresh; use in tincture, salve and fresh plant infusion**. I make extensive use of plantain, especially with skin issues/wounds/insect stings, and IBD, sometimes in the mouth. Radically underused in veterinary application. Learn this one thoroughly.
**Note wherever I say “water infusion” I mean , a strong tea, to use internally or to compress.
Sage (Salvia spp – officinalis, apiana ) Parts used: Leaf. Prepare as water infusion, using fresh or dried leaf, can use tincture or powder in capsules or honey. One of the popular go-to herbs for human use (sore throats!) but the salvias have so much more to offer. Because of the thujone content I use it more topically than internally, but it does go in some formulas I use for CCD (canine cognitive disorder) and to help dry up milk. I once made a mixture of honey, mallow and powdered sage and used on a dog who had porcupine quills in his throat(removed by owner). I hope to never have to do that again! but it was marvelously effective.
Mullein (Verbascum thapsus) Parts used: Leaf and flower, in water infusion and tincture. Only slightly astringent, mullein is a remedy for dry, non-productive coughs, I like it with chronic cases as well as acute. Included here as an example of a demulcent herb with some astringency (like Slippery and other elms) mullein is also mildly diuretic, mildly sedating(bear that in mind) and expectorant.. Respiratory system affinity.
Uva Ursi (Arctostaphyllos uva-ursi) Parts used: Leaf and flower. Prepare as water infusion, or use as tincture.One of the best herbs for the urinary tract, I use it in almost every case. Not for use with renal failure or acidic urine (urine is typically alkaline in the presence of bacterial infection). I generally use in tincture, often with other herbs. Can’t be without this one.
Raspberry (Rubus ideaus) Parts used: leaf. Prepare in water infusion or tincture, preferably infusion. Raspberry has a strong affinity for the reproductive system (female)– a wellknown and effective uterine tonic for dogs and cats. It can help with diarrhea, too; I’ve been known to grab a few leaves, brew up an infusion and pour over Danny’s dinner when he has had a bout of colitis – gentler than blackberry, but helpful and mild. Anyplace you need an astringent with no known side effects or drug interactions (see below) raspberry is helpful. I included some in a flush for anal gland infection I used last year on my partner’s dog (case study to follow) and I cleared the damn thing up in no time (to be fair, there was a lot of other stuff in there as well).
Slippery elm (Ulmus fulva) Parts used: Dried, powdered inner bark. Prepare as poultice, or infuse in water, or use directly(in food). Elm is one of the most popular herbs for the gastrointestinal tract, but it is useful in respiratory infection and skin eruptions as well, especially boils and abscesses. Elm has been over-harvested in the wild and should always be purchased from an ethical supplier, and used judiciously. This is one place where the popular “this for that” style herbalism has a dark side. Everyone uses elm, now, with dogs as well as our own uses; and while it is fabulous, so are many other herbs and herbal formulas. Use with respect.
And consider planting a couple, too: http://www.unitedplantsavers.org/content.php/438-Slippery-Elm
Self Heal (Prunella vulgaris)Parts used: Aerial parts, leaf, flower. Prepare in water infusion, in salve, I rarely use tincture but of course, you can. I have a truly magical relationship with this plant and use her for just about everything. She is mildly astringent, and I often ask her help for abscesses in cats, but especially where the cat is depressed (as in a rescue). Prunella has applications in so many things, including cancer, I plan a full entry devoted to her – soon.
My beloved ally for 25 years now, Self Heal (Prunella vulgaris)
Cranesbill (Geranium maculatum) Parts used: Rhizome. Prepare in decoction or use tincture (I prefer decoction) An indispensable astringent, used frequently for (human) hemorrhoid ointments, Cranesbill (Wild geranium) can also be used internally for upper and lower GI bleeding, for anal sac inflammation. An excellent, underused (in veterinary application) herb.
Yarrow (Achillea millefolium) Parts used: aerial tops, leaf and flower. Prepare in tincture, capsule, water infusions and salve. Yarrow is so bitter I prefer tincture for animals! Yarrow is one of the top ten or twelve herbs I believe we all need to know about and use. The list of actions this plant offers is huge; David Hoffman says “Astringent, anti-microbial, diuretic, anti-spasmodic, anti-inflammatory, bitter” so you can see the range of applications. Always allergy-test yarrow! (That’s a good idea for all herbs). Use for urinary tract and skin first, but get to know yarrow deeply. Much like elder, this is a medicine cabinet in one plant.
Eyebright (Euphrasia officinalis) Parts used: dried aerial parts, leaf and flower. Prepare in or water infusion. Despite the name, Eyebright has all kinds of applications, wherever an astringent, anti-inflammatory herb is called for.I make extensive use of euphrasia in my practise; it is wonderful for all kinds of sinus issues, making it incredibly helpful with feline chronic respiratory disease. (I have a doozy of a case stud coming up on that one). Most people associate eyebright with it’s name – and it is superb for inflamed eyes, conjunctivitis, veitis – but don’t think of it as only for the eye. Like other astringents, eyebright can be used on skin inflammations and for gastric upset as well.
Ground Ivy (Glechoma hederaceae)Parts used: aerial. Prepare in water infusion or tincture. I love ground ivy, especially after it proved to be one of the most important herbs for my own cat’s chronic respiratory disease. Generally well tolerated, dosing and pairing is important here. Use with bronchitis, kennel cough, any respiratory congestion, but do allergy-test first.
Lady’s Mantle (Alchemilla vulgaris) Parts used: leaf. Prepare in water infusion or tincture. Lady’s mantle has a wellknown affinity for the female reproductive system, acting as both astringent to alleviate excessive bleeding, and, potentially, an emmenagogue too ( meaning it can also stimulate flow.) Many herbs possess what seems like contradictory actions, but that’s a topic for another entry. I include Lady’s mantle here for her affinity with the uterus, possible application with pyometra and other reproductive issues.
Horsetail (Equisetum arvense) Parts used: stems. Prepare in tincture or infusion. This species of Equisetum is superb for urinary tract inflammation/inflection, I find it especially useful with spay-incontinence and in geriatric females in general. I like it more for acute conditions , and especially with elderly animals- silica uroliths are relatively rare in dogs, but horsetail is a very rich source. Use short term and never if the dog has had these bladder stones. (All that silicon does potentially support bone and cartilage formation, but I like to take a full history before using Horsetail for degenerative joint disease. It has a place there, but not generically).
White Oak bark (Quercus alba)Parts used: dried inner bark. One of my very favorites for inflamed, spongey gum tissues. I see this a lot in older rescue dogs, and in cats fed a cereal based kibble. Dogs are definitely easier to compress, orally! I usually mix the oak infusion with a few drops of echinacea tincture, and/or plantain.
Bayberry (Myrica cerifera) Parts used:bark. Prepare in decoction or tincture. Bayberry has other actions that may mean it’s not applicable internally for all animals, but it can be immensely helpful for others. I use most often, with periodontal disease, in compress or I will flush the mouth with a mixed water infusion that contains sage, myrrh, bayberry and white oak, with echinacea.
Witch Hazel (Hamamelis virginiana) Parts used: The leaves and bark of this beautiful shrub are very high in tannin and thus, very astringent. Witch hazel is a true Go-to for any place an astringent is called for, though most people think of the skin, I use it with all bleeding tumours, hemangiosarcoma and heavy bleeding in bitches during estrus. Important to balance the high tannin content with demulcents if using internally for any length of time. I make such use of Witch hazel, in compress for inflamed eyes, or for vulvitis, balanitis in male dogs, for cleaning ears (I prefer it most of the time to the very popular apple cider vinegar) and myriad other conditions. Important to note here that I am referring to infusion of the dried plant matter, not the witch hazel WATER commercially available, which contains alcohol, and not intended for internal use.
Blackberry (Rubus fructicosus) Parts used: powdered root, leaves. Prepare in water infusion, or give in capsules, or in honey.- main uses for me include relief of watery, acute diarrhea (powdered root) and water infusion of the leaf, for pruritis relief. I also carry the powder with me, straight up or mixed with yarrow, to staunch bleeding, while out in the field (me or Danny!)
Agrimony (Agrimonia eupatorium )Parts used: aerial. Prepare in water infusion or tincture. Agrimony is a lovely plant I think is a little underused, and a wonderful ally for urinary tract infection.I use it for wounds, for mild gastric upset(David Hoffman is big on agrimony for digestion, give it’s bitter action, but I use it less for digestion and more for urinary tract issues.) but most importantly with UTI or bladder stones. I have it wild all around this area, and maybe you do too?
Rose (Rosa rugosa) – Parts used: flowers. Prepare in tincture, water infusion, elixir, salve.The whole rose family have astringent properties; legendary herbalist Michael Moore coined the tern “YARFA” meaning Your Average Rose Family Astringent. Works for me! (Many of the plants listed here so far – blackberry, raspberry, hawthorn are Rose family). I love to work with wild local roses, which are highly astringent.I’ve found much variation in astringency, but they are all pretty potent! Rose goes into so many of my formulations, but one simple use is part of the infusion I use for feline abscess. Internally I use just a little with animals who are heartbroken from emotional suffering, and offset the astringency(try some tincture on your tongue!) I generally include mallow. Rose is very anti-inflammatory too; I’ve used in in compress and poultice for so many minor injuries and infections. I make rose petal vinegar and throw a cup into my coat rinses in summer(dogs). All my kennel cough remedies contain powdered rose hips….and so on. A must-have in my animal toolkit as well as my own use.
Some of my own rose medicine – two kinds of vinegar, a salve, elixir (brandy and honey) tincture, and massage oil brewing.
Again this is by no means an exhaustive list! Hyssop, Sumac, Stillingia, Cherry, Aspen and Ash, Bistort and Loosestrife - so many to work with. That said, my belief is (again) that it is preferable to become thoroughly acquainted with fewer herbs than possess a little knowledge about many, so I am sticking with these common, safe and easily obtained plants for now. Especially with animals, who may surprise us with their reactions, always test a herb in small quantity before giving it internally. This is good advice even with topical use; I once saw a Ridgeback (my own) break out in hives all over his stomach after a rinse of calendula infusion. Not what I predicted, but it taught me well.
Cautions specific to animal use: Susan Wynn writes that “all astringents may coagulate proteins and interfere with other drugs”. As with any herb you consider using, if the animal is on medications, consult a herbalist, or at the very least, look it up!
To recap (I know this was long): look to astringents when you have a condition that indicates a need for toning and contracting tissue. Look for the other actions in the herbs, for their affinities and how they have been traditionally used. And keep witch hazel, rose, uva ursi, yarrow, blackberry root, eyebright and oak bark always on hand! Those are my own staples – but don’t underestimate the others. Astringents have incredibly valuable medicinal actions, and you do well to pick a few and learn from them all.
We”ll look at demulcents in the next installment.
Veterinary Herbal Medicine, by Susan Wynn DVM and Barbara Fougeres DVM
Herbcraft, Jim MacDonald’s incredible site
Medical Herbalism, David Hoffman