Of the modern authors, Weiss discusses the use of tormentil at length and recommends it highly. He gives a description which refers to Potentilla erecta and considers it the best astringent in chronic enterocolitis, summer diarrhoea, paratyphoid diarrhoea, acute and sub-acute enteritis and colitis although less useful in chronic cases of colitis. He recommends a good pinch of powder (500 mg) several times a day. Weiss also recommends one cup several times a day of a decoction prepared with 1-3 tablespoons of rhizome, steeped for 15 minutes in 500 mL water. He advises use with a carminative such as chamomile Matricaria recutita, lemon balm Melissa officinalis or peppermint Mentha piperita. Weiss considers the tincture less effective but gives a dose of 30-50 drops several times a day in peppermint tea. He gives a formula of tinctures of tormentil 30 mL, Atropa belladonna leaf 5 mL and carminative tincture 15 mL, 30 drops three times a day. The final dose of Atropa belladonna should be calculated before considering use of this formula. The British Herbal Pharmacopoeia gives the main actions as astringent and anti-haemorrhagic and recommends it for ulcerative colitis and diarrhoea, including acute diarrhoea and diarrhoea associated with anxiety. Barker (2001) suggests it in tormina and colic, and small doses in peptic ulcer. Wood describes another Potentilla as he refers to a plant which has deeply serrated leaves and pictures a Potentilla with five leaflets and five petals. He finds the plant very similar in action to agrimony Agrimonia eupatoria, which one recalls is another Rosaceae used in problems of the digestive tract.
Chevalier recommends tormentil in irritable bowel syndrome, colitis, ulcerative colitis, dysentery and rectal bleeding. Low grade mucosal inflammation has been identified as a factor in the pathogenesis of irritable bowel syndrome and the indication given by all the authors for use in diarrhoea and blood in the motions suggests usage in inflammatory bowel disease such as ulcerative colitis and Crohn’s disease where orthodox treatment remains of limited effectiveness. The use of tormentil in inflammatory bowel disease and in irritable bowel syndrome where diarrhoea is the predominant symptom has been linked to the antioxidant activity of polyphenols. Tormentil and other astringent herbs have been investigated as researchers have asked whether astringency depends on the overall concentration of polyphenols or on the concentration of particular polyphenols. For example, root of Potentilla alba was shown to have a high level of condensed tannins and a high antioxidant activity in vitro. Bos et al (1996) investigated tormentil and found that the dimers and trimers inhibited lipid peroxidation and pentamers and hexamers inhibited the enzyme elastase. A study of antioxidant activity (superoxide formation) using the same extract found that the larger procyanidin pentamers and hexamers were the most active. Condensed tannins are common in foods and there is a high procyanidin concentration in foods from the Rosaceae family, such as apples and medicinal herbs such as hawthorn Crataegus monogyna. One could therefore conclude that particular compounds are responsible for the effectiveness of tormentil as an astringent rather than the overall content of procyanidins.
An in vitro study of herbs used in inflammatory bowel disease investigated their antioxidant activity as reactive oxygen metabolites are found in excess in colonic mucosa. Tormentil extract was found to inhibit superoxide and peroxyl formation and it was further found that incubation of inflamed tissue from human colorectal mucosal biopsies in a 1:1000 dilution of tormentil resulted in decreased formation of reactive oxygen metabolites. There is some evidence in clinical usage from a pilot study in 16 patients. The participants had active ulcerative colitis, mainly left-sided, and continued with orthodox treatment alongside three doses of tormentil extract each for 3 weeks with washout periods of 4 weeks. Scores on the Rachmilewitz colitis activity index decreased during each treatment phase and a dose of 2400 mg was found to be most effective. Stool frequency and blood in the stool decreased. Tests showed that the tannins were not systemically absorbed.
An unusual clinical trial was undertaken in Russia where children are routinely admitted to hospital with diarrhoea to avoid further spread in the community so a clinical priority is to stop the intensity of the diarrhoea. Forty children were included who were admitted with diarrhoea and whose stool samples were positive for rotavirus antigen. The children were given 3 drops of tincture per year of age three times a day of either tormentil or a placebo. The 1:10 tincture was made from dried root using 40% ethanol. The treatment group was aged 4-79 months (median 23.5) and the control group 3-60 months (median 24.5). Both groups were also given oral rehydration therapy. The outcome for the treatment group was significantly better as regards volume of parenteral rehy-dration required, duration of abnormal stool consistency and duration of hospitalization. For example, after 48 hours diarrhoea had ceased in 8 of 20 in the treatment group but in only 1 of 20 in the control group. Tormentil did not reduce the rate of vomiting. This study is useful as it is a study whose results can be applied in normal herbal practice as the dose and the preparation is clearly stated. The results are all the more interesting as the placebo was a tincture of Indian tea. Indian black tea has been shown to inhibit bovine rotavirus in vitro and is used to treat diarrhoea.