Antidiarrheal

An ethanolic root extract at 25–100 mg/kg dose-dependently reduced faecal output by 29–60% and cut intestinal fluid accumulation in the castor-oil model, slowed gastrointestinal transit, and preferentially reduced luminal sodium while lowering lipid peroxidation ^{1Reference 1Amresh et al. · 2004AnimalEthnomedical value of Cissampelos pareira extract in experimentally induced diarrhoea — animal modelView study →}.

The sodium finding is the informative one. Castor-oil diarrhoea is secretory, driven by fluid following ions into the lumen, so reducing luminal sodium acts on the pathophysiology rather than simply slowing transit.

It also matches the herb’s widespread traditional use for dysentery and diarrhoea.

The evidence is a single study in an acute model, with no infectious, chronic or human data. Abuta’s antifertility activity ^{21Reference 21Ganguly et al. · 2007AnimalAntifertility activity of the methanolic leaf extract of Cissampelos pareira in female albino mice — animal model (mice)View study →} applies to this use as much as any other.

In the charcoal-meal test in rats an extract at 300 mg/kg inhibited intestinal propulsion by 30–57%, a moderate effect equal to or greater than loperamide at 10 mg/kg ^{22Reference 22Calzada et al. · 2010AnimalEffect of plants used in Mexico to treat gastrointestinal disorders on charcoal-gum acacia-induced hyperperistalsis in rats — animal modelView study →}. Combined with activity against the diarrhoea-causing protozoa Entamoeba histolytica and Giardia ^{23Reference 23Said-Fernández et al. · 2005In vitroIn vitro antiprotozoal activity of the leaves of Artemisia ludoviciana — in vitroView study →}, that gives two routes rather than one.

The aerial-parts infusion is drunk for stomach pain, diarrhoea, intestinal parasites and empacho across Mexican traditional practice, casually and often.

The motility work is a single screening study with no mechanism specified, and there is no human data.

The extract produced dose-dependent antidiarrhoeal and antisecretory activity in mice alongside spasmolysis, all on the same potassium-channel mechanism ^{4Reference 4Mehmood MH et al. · 2015In vitroAntidiarrhoeal, antisecretory and antispasmodic activities of Matricaria chamomilla are mediated predominantly through K⁺-channels activation — animal / in vitro studyView study →}. Direct evidence of that kind is more than most antidiarrhoeal tags carry.

A systematic review of herbal medicines in paediatric gastrointestinal disorders found promising evidence for a Matricaria chamomilla-containing preparation in diarrhoea, though chamomile was one component of a multi-herb product ^{5Reference 5Anheyer D et al. · 2017Systematic reviewHerbal medicines for gastrointestinal disorders in children and adolescents: a systematic reviewView study →}.

This is a motility and secretion effect rather than a tannin-astringent one.

The fruit carries two opposing fractions. At low doses the hydrolysable tannins dominate — chebulinic and chebulagic acids, corilagin, gallic and ellagic acids — producing a binding, astringent effect.

At higher doses the anthraquinone glycosides drive a laxative action. The same fruit checks loose stool and relieves constipation, and Ayurveda describes the split explicitly.

The dividing line is roughly three grams of fruit powder: one to two grams is the antidiarrhoeal dose, three to six the laxative one.

Chinese medicine works the same face of it. He Zi is said to bind the Intestines, and is given in decoction for chronic diarrhoea and dysentery.

The caution attaches to the laxative dose rather than to the herb: high or prolonged doses cause cramping, loose stools and dehydration, so the larger amounts are what to avoid in active diarrhoea. There are no trials of haritaki alone for either direction — the human data sit with Triphala.

Indigenous peoples across North America decocted the astringent inner bark for diarrhoea and fevers, and that remains the plant’s best-documented traditional use. Its confirmed hydrolysable-tannin content is the basis of the mechanism.

The modern support is indirect. Leaf and stem extracts consistently altered gut microbiota and reduced enteric pathogens in poultry, pigs and ruminants ^{6,7,8,9,10Reference 6Zheng et al. · 2021AnimalDietary supplementation of red-osier dogwood polyphenol extract changes the ileal microbiota structure and increases Lactobacillus in a pig model — in vivo animal modelView study →Reference 7Erinle et al. · 2022RCTEffect of red osier dogwood extract on growth performance, blood biochemical parameters, and gut functionality of broiler chickens challenged with Salmonella Enteritidis lipopolysaccharide — randomised in vivo animal modelView study →Reference 8Erinle et al. · 2023RCTRed osier dogwood extract versus trimethoprim-sulfadiazine (Part 1): growth performance, blood parameters, gut histomorphometry and Salmonella excretion in broiler chickens — randomised in vivo animal modelView study →Reference 9Erinle et al. · 2023AnimalRed osier dogwood extract versus trimethoprim-sulfadiazine (Part 2): pharmacodynamic effects on ileal and cecal microbiota of broiler chickens — in vivo animal modelView study →Reference 10Santos Reis Pereira et al. · 2026RCTEffects of red osier dogwood extract on growth, protein digestibility, immune response and gut health of broiler chickens in a coccidiosis vaccine challenge model — randomised in vivo animal modelView study →}.

That work uses a different plant part from the traditional bark and is livestock rather than human, though it is more substantial than an in-vitro result.

The root and aerial parts are decocted as an astringent for diarrhoea and digestive complaints, the classic Rosaceae tannin application. The use appears independently in European folk practice and in Tibetan medicine, where the root is a cultivated food as well as a remedy.

Nothing has measured it. The tannin chemistry is confirmed and the bowel effect is inferred from it.

An aqueous bark decoction-equivalent reduced enterotoxigenic E. coli diarrhoea in mice by lowering intestinal cAMP, prostaglandin E₂ and fluid accumulation, while restoring intestinal alkaline phosphatase, myeloperoxidase and IL-1β and cutting bacterial shedding ^{17Reference 17Veena et al. · 2021AnimalMolecular mechanism of Escherichia coli H10407-induced diarrhoea and its control through immunomodulatory action of bioactives from Simarouba amara (Aubl.) — mouse in vivoView study →}. That maps onto the secretory-diarrhoea pathway, so the mechanism is antisecretory and anti-infective rather than astringent.

The amoebicidal work supports the same picture for dysentery ^{18,19Reference 18Wright et al. · 1988In vitroUse of microdilution to assess in vitro antiamoebic activities of Brucea javanica fruits, Simarouba amara stem, and quassinoidsView study →Reference 19Wright et al. · 1993In vitroQuassinoids exhibit greater selectivity against Plasmodium falciparum than against Entamoeba histolytica, Giardia intestinalis or Toxoplasma gondii in vitroView study →}, with one historical human thread: glaucarubin, a crystalline glycoside from the sibling S. glauca rather than S. amara bark, treated colonic amoebiasis in an uncontrolled 1956 series ^{20Reference 20Van Assendelft et al. · 1956Case reportThe use of glaucarubin (a crystalline glycoside from Simarouba glauca) in the treatment of human colonic amebiasis — clinical case seriesView study →}.

The animal study is single and unreplicated, the extract was not standardised to any marker quassinoid, and the bark’s quassinoid content has never been quantified, so no whole-herb dose can be defended.

The same bitter principles provoke nausea and vomiting above the therapeutic window, which is what limits the dose.