Herbal medicines for the management of irritable bowel syndrome: A comprehensive review

Table 1 Single herbs used for treatment of irritable bowel syndrome

Scientific name	Part	Type of study	Model	Concomitant drugs	Duration of study	Results	Ref.
Aloe vera	Gel	Placebo-controlled double-blind trial	IBS patients	-	1 mo	No difference between treatment and placebo groups in response to treatment at 1 mo diarrhea-predominant patients showed a trend towards a response to treatment at 1 mo	[17]
Curcuma longa	Rhizome	Partially blinded, randomized, two-dose, pilot study	IBS patients	-	8 wk	↓Abdominal pain/discomfort score Significant improvements in IBS QOL scales Approximately two thirds of all subjects reported an improvement in symptoms after treatment	[18]
Curcuma xanthorrhiza	Rhizome	Randomized, double-blind, placebo-controlled trial	IBS patients	-	18 wk	↑IBS-related pain ↓IBS-related distension but more decrease was seen in placebo The global assessment of changes in IBS symptoms and psychological stress due to IBS did not differ significantly among groups	[19]
Cynara scolymus	Aqueous-alcohol extract of leaf	Postmarketing surveillance study	IBS patients	-	6 wk	↓Severity of symptoms reported by both physicians and patients 96% of patients rated this drug as better than or at least equal to previous therapies Very good tolerability	[24]
	Aqueous extract of leaf	Dose-ranging, open, postal study	IBS patients	-	2 mo	↓IBS incidence by 26.4% A significant shift in self-reported usual bowel pattern away from “alternating constipation/diarrhea” toward “normal”↓NDI total symptom score by 41% 20% improvement in the NDI total QOL score	[23]
Fumaria officinalis	Whole plant	Randomized, double-blind, placebo-controlled trial	IBS patients	-	18 wk	↓IBS-related pain ↑IBS-related distension The global assessment of changes in IBS symptoms and psychological stress due to IBS did not differ significantly among group	[19]
Hypericum perforatum	Aerial parts	Randomized, double-blind, placebo-controlled trial	IBS patients	-	12 wk	↓Overall BSS in both groups with the placebo arm having significantly lower scores at 12 wk compared with Hypericum group A similar proportion of subjects in each treatment group believed that the study drug they received decreased IBS life interferences	[28]
		Open-label, uncontrolled trial	IBS women	-	8 wk	↓autonomic nervous system to different stressor Improvement of Gastrointestinal symptoms of IBS	[29]
Iberis amara	Whole plant extract	Double-blind, randomized, placebo-controlled, multi-centre trial	IBS patients	-	4 wk	Significant improvement in IBS symptom scale and abdominal pain scale in Iberis group compared with placebo	[44]
Maranta arundinacea	Root	Uncontrolled	Diarrhea predominant- IBS patients	-	1 mo	↓Diarrhoea ↓Abdominal pain	[30]
Menthe piperita	Essence	Prospective double blind placebo-controlled randomized trial	IBS patients	-	4 wk	75% of the patients in the treatment group showed a > 50% reduction of basal total IBS symptoms score compared with 38% in the placebo group (P < 0.009) a statistically significant reduction of the total IBS symptoms score in treatment group compared with T (0), while no change was found with the placebo	[34]
		Randomized double-blind placebo-controlled study	IBS patients	-	8 wk	The number of subjects free from abdominal pain or discomfort changed from 0 at wk 0 to 14 at wk 8 in the treatment group and from 0 to 6 in controls (P < 0.001). ↓Severity of abdominal pain significantly in the drug group as compared to controls Improvement in the QOL in the treatment group There was no significant adverse reaction	[33]
		Randomized, double-blind controlled trial	IBS patients	-	2 wk	76% of the patients receiving peppermint oil reported changes in the severity of symptom scale at the end of trial compared with 19% receiving placebo	[35]
						Improvements in the change of symptom scale in 71% of the patients receiving peppermint oil compared with 43% receiving placebo
						No significant differences between groups in the Gastrointestinal Symptom Rating Scale
						No changes in symptoms such as abdominal rumbling, abdominal distention, belching, gas, and heartburn in treatment group compared with placebo
						Mean severity of pain symptoms in the treatment group was significantly lower than that in the placebo
			IBS patients	-	1 mo	Significant reduction in the abdominal pain, abdominal distension, stool frequency, borborygmi, flatulence in the treatment group compared to placebo	[32]
						Symptom improvements after essence therapy were significantly better than after placebo
						No significant changes in liver function test results.
Paeonia lactiflora	Paeoniflorin; Active principle of root	In vivo	Neonatal maternal separation-induced visceral hyperalgesia in rats	-	Single dose	A dose-dependent analgesic effect Blockage of analgesic effect of Paeoniflorin by nor-binaltorphimine, dl-α-methyltyrosine, and yohimbine. Analgesic effect may be mediated by kappa-opioid receptors and α(2)-adrenoceptors in the central nervous system	[39]
Plantago psyllium	Seed	Randomized placebo controlled trial	IBs patients	-	12 wk	Significantly greater proportion of responders in the psyllium group than in the placebo group	[40]
						↓Symptom severity significantly in the psyllium group compared with the placebo
						No differences in QOL

IBS: Irritable bowel syndrome; QOL: Quality of life; NDI: Nepean dyspepsia index; BSS: Bowel symptom score.

Table 2 Combination herbal therapies used for irritable bowel syndrome

Name of preparation	Composition (part)	Type of study	Model	Concomitant drugs	Duration of study	Results	Ref.
Carmint	Mentha piperita (leaf)	Double-blind, randomized, placebo-controlled, multicenter clinical trial	IBS patients	Loperamide or psyllium (based on their predominant bowel function)	8 wk	Severity and frequency of abdominal pain/discomfort were significantly lower in the Carmint group than the placebo group	[41]
	Melissa officinalis (leaf)
	Coriandrum sativum (fruit)
CHM	Codonopsis pilosulae (root)	Randomized, double-blind, placebo-controlled trial	IBS patients	-	16 wk	Significant improvement in bowel symptom scores as rated by patients and by gastroenterologists	[42]
	Agastaches seu pogostemi (whole plant)					Significant global improvement as rated by patients and by gastroenterologists
	Ledebouriella sesloidis (root)					Patients reported that treatment significantly ↓ the degree of interference with life caused by IBS symptoms
	Coicis lachryma-jobi (seed)
	Bupleurum chinensis (whole plant)
	Artemisia capillaries (whole plant)
	Atractylodis macrocephalae (rhizome)
	Magnolia officinalis (bark)
	Citrus reticulata (pericarp)
	Zingiber officinale (rhizome)
	Fraxinus spp. (bark)
	Poria cocos (sclerotium)
	Angelica dahurica (root)
	Plantago spp. (seed)
	Phellodendron spp. (bark)
	Glycyrrhiza uralensis (root)
	Paeonia lactiflora (root)
	Saussurea lappa (root)
	Coptidis spp. (rhizome)
	Schisandra spp. (fruit)
C-IBS formula	Lactulose Ulmus fulva (bark) Glycyrrhiza glabra (root) Avena sativa (bran)	A two arm, open-label, uncontrolled pilot study	Constipation-predominant IBS	-	2 wk	A 20% increase in bowel movement frequency ↓ in straining, abdominal pain, bloating, and global IBS symptom severity improvements in stool consistency well-tolerated	[54]
DA-IBS formula	Vaccinium myrtillus (fruit)	A two arm, open-label, uncontrolled pilot study	Diarrhea-predominant and alternating bowel	-	2 wk	a small, but significant increase in bowel movement frequency	[54]
	Ulmus fulva (bark) Cinnamomum zeylanicum (bark)		habit IBS patients			↓ in straining, abdominal pain, bloating, flatulence, and global IBS symptoms well-tolerated
	Agrimonia eupatoria (aerial part)			-
Iberogast (STW 5)	Iberis amara (whole plant)	In vitro	Human intestinal mucosa/submucosa preparations			A dose-dependent increase in ion secretion in human tissue and T84 cells evoke an increased spike discharge in 51% of human submucous neurons	[45]
	Chelidonium majus (root)		human epithelial cell line T84 human enteric neurons
	Silybum marianum (fruit)
	Melissa officinalis (leaf)
	Carum carvi (fruit)
	Glycyrrhiza glabra (root)
	Angelica sinensis (root)	In vivo	Wistar rats	-	Single dose	↑Afferent discharge to 5-HT and bradykinin dose-dependently	[47]
	Matricaria recutita (flower)
	Mentha piperita (leaf)	Double-blind, randomized, placebo-controlled, multi-centre trial	IBS patients	-	4 wk	Significant improvement in IBS symptom scale and abdominal pain scale in STW 5 group compared with placebo	[44]
STW 5-II	Iberis amara (whole plant) Melissa officinalis (leaf) Carum carvi (fruit)	Double-blind, randomized, placebo-controlled, multi-centre trial	IBS patients	-	4 wk	Significant improvement in IBS symptom scale and abdominal pain scale in STW 5-II group compared with placebo	[44]
	Glycyrrhiza glabra (root)
	Matricaria recutita (flower)
	Mentha piperita (leaf)
Padma Lax	Aloe barbadensis A. ferox (extract)	Randomized, double-blind, placebo-controlled trial	Constipation predominant-IBS patients	-	3 mo	Significant improvement compared to placebo in constipation, severity of abdominal pain, incomplete evacuation, abdominal distension and flatus/flatulence	[43]
	Jateorhiza palmata (root)					Significantly more Padma Lax patients compared to placebo rated the current treatment superior to previous therapies tried for IBS
	Marsdenia condurango (bark), Rhamnus frangula (bark)					Laboratory parameters displayed no clinically significant changes
	Gentiana lutea (root)
	Inula helenium (rhizome)
	Terminalia chebula (fruit)
	Piper longum (fruit) Rhamnus purshiana. (bark)
	Rheum palmatum (root)
	Strychnos nux-vomica (seed)
	Zingiber officinale (root)
TXNG	Paeonia lactiflora (root)	Prospective, randomized, double-blind, placebo-controlled trial	Diarrhea predominant-IBS patients	-	3 wk	↓IBS-related pain in the TXNG group compared with the placebo	[52]
	Atractylodes macrocephala (rhizome)					↓Frequency and the duration of abdominal pain between the TXNG group and the placebo
	Citrus reticulate (green unripe exocarp)					Improvement of IBS-related stool in form or appearance in the TXNG group in comparison with the placebo
	Allium macrostemon (bulb)					↓Stool frequency in the TXNG group compared with the placebo
						Improvement of stool passage (urgency or
						Feeling of incomplete rectal emptying) in the TXNG group compared with the placebo.
						Improvement in IBS-related diarrhea in the TXNG group compared to placebo
						No statistical difference in either the effective time of IBS-related pain or the effective time of IBS-related diarrhea between the two groups
						↓IBS-related pain alleviation time and the IBS-related diarrhea alleviation time in the TXNG group compared to those in the placebo group
TXYF	Atractylodes macrocephala (rhizome)	In vivo	Maternal separation-induced visceral hypersensitivity rats	-	2 wk	↓Pain threshold pressure and abdominal withdrawal reflex scores in a dose-dependent manner	[54]
	Paeonia lactiflora (root)					↓ 5-HT levels in serum
	Citrus sinensis (dried old peel)					↓Corticotrophin releasing factor concentrations in the brain
	Ledebouriella divaricata (root)					Visceral hypersensitivity alleviation was dependent on the substance P expression in the colon mucosa
		Randomized placebo-controlled trial	Diarrhea predominant-IBS patients	Miyarisan	4 wk	No significant difference between two groups in terms of the total efficacy or the scores of symptoms before and after treatment	[53]
						↓The number of activated mast cells in the intervention
TCM	Atractylodes macrocephala (rhizome)	Randomized placebo-controlled trial	Diarrhea predominant-IBS patients	-	16 wk (8 wk drug administration +8 wk follow up)	No significant difference in the proportion of patients with global symptom improvement between the TCM and placebo groups at week 8 and at week 16	[51]
	Astragalus membranaceus (root)					No difference in individual symptom scores and the quality-of-life assessment between the two groups at all time points
	Paeonia lactiflora (peeled root, fried)
	Atractylodes chinensis (rhizome)
	Bupleurum chinense (root)
	Citrus reticulata (peel)
	Saposhnikovia divaricata (root)
	Paniculata (twigs)
	Punica granatum (rind)
	Portulaca oleracea (above-ground parts)
	Coptis chinensis (rhizome)

CHM: Chinese herbal medicine; TXNG: Tong-xie-ning; TXYF: Tong-Xie-Yao-Fang; TCM: Traditional Chinese Medicine; 5-HT: Serotonin; spp.: Schisandra chinensis.