Review of Medicinal Plants Traditionally Used to Treat Diarrhea by the People in the Amhara Region of Ethiopia

Table 2

In vivo trials of medicinal plants to confirm the traditional claim of their utilization in treating diarrhea.

Medicinal plant	Plant parts used	Extraction method	The effects obtained	Chemical composition	Proposed mechanism of action	References for trial
Calpurnia aurea	Leaves	Maceration in 80% methanol	Reduced the time of diarrhea onset, defecation frequency, and fecal weight	Alkaloids, flavonoids, tannins, terpenoids, and saponins	Antimicrobial activity	[41]
Clutia abyssinica	Roots	Cold maceration in 80% methanol	Prolonged the onset of diarrhea, and significantly reduced the number of wet and total stools at doses of 200 and 400 mg/kg	Tannins, flavonoids, alkaloids, saponins, phenols, terpenoids, anthraquinones, and glycosides	Antisecretory effect, anti-inflammatory activity, and inhibition of peristaltic movements	[42]
Coffea arabica	Seeds	Cold maceration in 80% methanol	At a dosage of 400 mg/kg, there was a significant prolongation of the onset of diarrhea and a decrease in the total number of feces	Alkaloids, flavonoids, phenols, tannins, saponins, steroids, anthraquinones, glycosides, and terpenoids	Anti-inflammatory activity, increased sympathetic nerve activity, antioxidant activity, increase of the intestinal absorption of water and electrolytes	[43]
Cordia africana	Bark	Maceration in 80% methanol	Reduction in castor oil-induced diarrhea and intestinal fluid accumulation in a dose-dependent manner	Phenols, flavonoids, terpenoids, and saponins	Increase in water and electrolyte absorption or decrease the secretion of fluid and electrolytes, blocking the prostaglandin receptors	[44]
Croton macrostachyus	Leaves	Soxhlet extraction with chloroform and methanol	Delayed onset of diarrhea, reduced stool frequency, and lighter feces	Alkaloids, steroids, and terpenoids in the chloroform fraction; alkaloids, saponins, tannins, flavonoids, and cardiac glycosides in methanol fraction; and saponins, tannins, and alkaloids in aqueous fraction	Inhibition of intestinal motility and hydro-electrolytic secretion, inhibition of the intestinal secretory response induced by prostaglandins E2, promotion of fluid and electrolyte absorption	[45]
Ficus thonningii	Leaves	Aqueous methanolic extraction	An initial increase in purgation was observed by the 2nd hour of the test, followed by a subsequent period of constipation	Tannins, flavonoids, saponins, and anthraquinone glycosides	A dose-related reduction in intestinal motility	[46]
Leonotis ocymifolia	Leaves and fruits	Cold maceration in 80% methanol	Reduced diarrhea frequency, delayed onset of diarrhea, and decreased number of defecation occurrences	Alkaloids, tannins, flavonoids, and saponins	The antisecretory effect, antimotility effect, and reduction of intestinal transit	[47]
Lepidium sativum	Seeds	Maceration in 70% methanol	The doses of 100 and 300 mg/kg exhibited a significant antidiarrheal effect	Alkaloids, saponins, and anthraquinones	Reversing the CCh and high K + -induced contractions, dual blockade of muscarinic receptors, and Ca++ channels	[48]
Myrtus communis	Leaves	Maceration in 80% methanol	Significant delays of the onset of diarrhea and decreases of the frequency and weight of fecal outputs, at 200 and 400 mg/kg extract. A significant effect on the frequency and weight of wet feces, as well as the total fecal output, at 100 mg/kg of the extract	Terpenoids, flavonoids, tannins, glycosides, and saponins	Anti-inflammatory activity, suppression of the biosynthesis of eicosanoids, reduction of gastrointestinal motility	[49]
Ocimum lamiifolium	Leaves	Maceration in 80% methanol	The intervention resulted in a reduction in the onset of diarrhea, the number of wet feces, the weight of fresh feces, and the fluid content of feces, as well as reductions in both the volume and weight of intestinal content	Alkaloids, flavonoids, phenols, tannins, saponins, steroids, glycosides, anthraquinones, terpenoids	Anti-inflammatory activity, antioxidant activities, inhibition of prostaglandin synthesis, reduction of intestinal secretion, decrease in the synthesis of nitric oxide, and inhibition of intracellular Ca^2+ inward current	[50]
Punica granatum	Peels	Aqueous extract (decoction)	Reduction in diarrhea, inhibition of wet or unformed feces production, and suppression of gastrointestinal propulsive action	Tannins, alkaloids, and flavonoids	Inhibition of intestinal motility and accumulation of intestinal fluid	[51]
Ruta chalepensis	Leaves	Maceration in 80% methanol	Prolonged the onset time of diarrhea and decreased the stooling frequency at 200 mg/kg and 400 mg/kg. Additionally, there was a reduction in the percentage of mean fecal output	Alkaloids, tannins, saponins, flavonoids, cardiac glycosides, terpenoids, and steroids	Inhibition of the production of prostaglandin E2 and an antispasmodic effect	[52]
Sorghum bicolor	Seeds	Maceration in 80% methanol	Observation of reduced intestinal fluid weight (in grams) and delayed charcoal meal propulsion through the gastrointestinal tract	Phenols, flavonoids, tannins, terpenoids, and steroids	Inhibition of motility and secretion of the gastrointestinal tract	[53]
Stephania abyssinica	Leaves and roots	Methanol and aqueous extract	Exhibiting an inhibitory effect on both gastrointestinal propulsion and fluid secretion, as well as demonstrating antispasmodic activity	Isoqiunol alkaloids	Decrease of hypermotility, inhibition of prostaglandin biosynthesis, anticholinergic effect, and histamine decrease	[54]
Syzygium guineense	Leaves	Maceration in 80% ethanol	Inhibition of intestinal propulsion, reduction in the number of watery stools, reduction of intraintestinal fluid volume, and passage of watery stool	Pentacyclic triterpenes and luteolin	Inhibition of acetylcholine-mediated intestinal smooth muscle contraction; stimulation of dopamine D2 receptor; and degradation of acetylcholinesterase	[55]
Withania somnifera	Leaves	Maceration in 80% methanol	Delayed the diarrhea onset at 200 and 400 mg/kg; reduced defecation of diarrheal stools (number of wet stools), total stools (wet and dry), and weight of fresh stools; decreased intraluminal fluid accumulation and charcoal meal movement	Flavonoids, alkaloids, tannins, steroids, phenols, terpenoids, and saponins	Antisecretory action, enhancing of absorption, and/or anti-motility action, anti-inflammatory activity, antispasmodic activity, calcium antagonism action	[56]
Zehneria scabra	Leaves	Maceration in 80% methanol	Reduced the mean stool score, wet feces, defecations, stool fluid content, intestinal motility, and weight of intestinal content	Tannins, saponins, anthraquinones, O-anthraquinones, and phenols	Inhibition of secretion, reducing intraluminal fluid accumulation, or enhancing water absorption but not delaying motility	[57]
Ziziphus spina-christi	Stem bark	Soxhlet extraction with methanol	Copious diarrhea was inhibited, intraluminal accumulation of fluid volume was reduced, and intestinal transit of charcoal meal decreased	Glycosides, resins, saponins, and tannins	Tannins inhibit electrolyte permeability and prostaglandin release and display antimicrobial activity. They also reduce secretion and enhance intestinal mucus resistance through protein tannate formation	[58]