What is Rhubarb?
There are three species of rhubarb used medicinally (Rheum palmatum, R. tanguticum, and R. officinale), all found in temperate zones around the world.
Rhubarb rhizomes have a strong, bitter flavor, mostly as a result of their high anthraquinone content. These anthraquinones are also what gives rhubarb its laxative and astringent qualities.
It's important to consider safety when using any herb with anthraquinones. It should only be used under the guidance of a trained practitioner if using this herb for anything more than as a bitter in small doses.
Other parts of the rhubarb plant, such as the brightly colored leaf stalks are popular for their tart flavor when making soups and pie.
What is Rhubarb Used For?
Rhubarb is mainly used as a bitter in small doses to stimulate the flow of bile from the liver/gallbladder and to aid digestion. It is also used for diarrhea in smaller doses, and for constipation in higher doses.
Traditional Uses of Rhubarb
+ Western Herbal Medicine
It has been used traditionally as a mild stimulating tonic to the digestive mucous membrane, liver, and gall ducts, and removes mucous. In smaller doses, it was considered a hepatic, while large doses were used as a cathartic. [16].
+ Traditional Chinese Medicine
Pinyin: Dá Huáng
Taste: Bitter [17, 18]
Energy: Cold [17, 18]
Channels: Spleen, stomach, large intestine, liver, heart [18]
Actions: Purges heat and accumulations, loosens bowels, promotes blood circulation, removes stagnation, drains fire, removes blood stasis and invigorates blood [2-4, 17, 18].
Indications: Constipation due to heat accumulation, accumulation in intestine, abdominal pain, damp-heat jaundice, blood heat hemorrhage, red eyes, sore throat, intestinal abscesses, swellings, sores, and ulcers [17].
Herb Details: Rhubarb
Herbal Actions:
- Bitter
- Laxitive [1]
- Cholagogue
- Antimicrobial
- Antineoplastic
- Hepatoprotective
- Nephroprotective
- Astringent (low dose)
- Styptic
- Stomachic (low dose)
Weekly Dose
- (1:2 Liquid Extract)
10–30 mL - View Dosage Chart
Part Used
- Rhizome, stalks
Family Name
- Ploygonaceae
Distribution
- Temparatee zones around the world.
Constituents of Interest
- Aloe-emodin
- Chrysophanol
- Calcium oxylat
Common Names
- Rhubarb
- Chinese rhubarb
- Da Huang (China)
CYP450
Unknown
Duration of Use
- Avoid long-term use in therapeutic doses.
Botanical Information
Rhubarb is a member of the Polygonaceae family of plants. This family is also referred to as the buckwheat family. There are 1200 species in this family, and about 48 genera.
Other notable members of this family include Rumex crispus (yellow dock), and Fagopyrum esculentum (buckwheat).
Habitat Ecology, & Distribution:
Although various species of rhubarb are cultivated all over the world, it is mainly found naturally in Northern China and Tibet.
Harvesting, Collection, & Preparation:
Rhubarb proliferates quickly and can reach heights of up to 3m high, only to die back to the soil each winter. Rhubarb is an easy garden vegetable/medicine species and is easy to cultivate in both shady, and sunny locations.
Pharmacology & Medical Research
+ Blood-Brain Barrier Attenuation
Rhubarb is reported to attenuate the BBB after hemorrhagic stroke in rats. The mechanism of action was suggested to be through increased zonula-occludens-1 expression [9]. This may prove a useful medicine for neuroprotection in intracerebral hemorrhages in the future, more research is needed.
+ Laxative
The laxative actions of rhubarb were investigated in a rat model. The study found that rhubarb (Rheum palmatum) influenced ion transport (Na+ and Cl-) across the rat ileum epithelia [1].
Anthraquinone's, which are contained in rhubarb root in high amounts are well known to produce laxative effects within the body [13].
[Suggested to be due to stimulation of intestinal musculature, probably via prostaglandin mediation - takes 8-14 hours after ingestion]
+ Kidney Protective
Rhubarb has been shown to have a beneficial effect on chronic and acute renal failure in vivo [10, 11].
Its been found to have the ability to reduce proteinuria, as well as generally improve renal function when used alone. Synergy has been suggested for this action when used with angiotensin-converting enzyme inhibitors [11].
In a study investigating the protective effects of 4 rhubarb extracts on HgCl2-induced acute renal failure (ARF) found that the anthraquinone containing extract had significant protective actions on the kidneys using this model [14]. More research is needed to determine whether this effect is exclusive to rhubarb, or if other anthraquinone containing herbs can achieve the same action.
Clinical Applications Of Rhubarb:
Rhubarb is reliable for promoting a change in bowel movements. It can be used on the smaller end of the dosage for treating diarrhea, and on the higher end of the dosage for constipation. Additionally, the intense bitter flavour of rhubarb makes it useful in small doses as a bitter for stimulating digestion and liver function.
One area deeming further research is for its ability to attenuate the blood brain barrier. This may be a useful mechanisms for antipsychotic medications, nervines, and nootropics in the future.
Cautions:
Avoid rhubarb if taking medications for a heart condition or medications that affect potassium loss through the kidneys.
May increase the effect of cardiac glycosides and interact with antiarrhythmic drugs through promoting the loss of potassium [16].
May decrease the absorption of other drugs through a decrease in transit time. [16].
May discolor the urine with a red or yellow hue. [16].
Synergy
Synergy has been suggested for rhubarbs kidney protective actions when used with angiotensin-converting enzyme inhibitors [11].
This may include herbs such as Camellia sinensis, Hibiscus sabdariffa, Vaccinum mytrillus, or Cryptomeria japonica [15].
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References:
Tsai, J., Tsai, S., & Chang, W. (2004). Effect of Ethanol Extracts of Three Chinese Medicinal Plants with Laxative Properties on Ion Transport of the Rat Intestinal Epithelia. Biol. Pharm. Bull, 27(2), 162-165. doi:10.1248/bpb.27.162
Zhao, L., Liang, J., Li, W., Cheng, K., Xia, X., Deng, X., & Yang, G. (2011). The Use of Response Surface Methodology to Optimize the Ultrasound-Assisted Extraction of Five Anthraquinones from Rheum palmatum L. Molecules, 16(12), 5928-5937. doi:10.3390/molecules16075928
Chen, D.C.; Wang, L. (2009). Mechanisms of therapeutic effects of rhubarb on gut origin sepsis. Chin. J. Traumatol. 12, 365-369.
Feng, S. (2000). Mechanism of Rhubarb in preventing the occurrence of gastrointestinal function failure. Zhongguo Zhong Xi Yi Jie He Za Zhi 20, 795-797.
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Chai; Y.F.; Ji, S.G.; Wu, Y.T.; Liang, D.S.; Xu, Z.M. (1998). The separation of anthraquinone derivatives of rhubarb by miceller electrokinetic capillary chromatography. Biomed. Chromatogr. 12, 193-195.
Zhou, X.; Song, B.; Jin, L.; Hu, D.; Diao, C.; Xu, G.; Zou, Z.; Yang, S. (2006). Isolation and inhibitory activity against ERK phosphorylation of hydroxyanthraquinones from rhubarb. Bioorg. Med. Chem. Lett. 16, 563-568.
Ji, S.G.; Chai, Y.F.; Wu, Y.T.; Yin, X.P.; Xiang, Z.B.; Liang, D.S.; Xu, Z.M.; Li, X. (1998). Separation and determination of anthraquinone derivatives in rhubarb and its preparations by micellar electrokinetic capillary chromatography. Biomed. Chromatogr. 12, 335-337.
Wang, Y., Peng, F., Xie, G., Chen, Z., Li, H., Tang, T., & Luo, J. (2016). Rhubarb attenuates blood-brain barrier disruption via increased zonula occludens-1 expression in a rat model of intracerebral hemorrhage. Experimental and Therapeutic Medicine. doi:10.3892/etm.2016.3330
Jha, V. (2010). Herbal medicines and chronic kidney disease. Nephrology 15, 10–17.
Zhong, Y.; Deng, Y.; Chen, Y.; Chuang, P.Y.; He, J.C. (2013). Therapeutic use of traditional Chinese herbal medications for chronic kidney diseases. Kidney Int. 84, 1108–1118.
Ye, M.; Guo, D.A.; Han, J.; Chen, H.B.; Zheng, J.H. (2007). Analysis of phenolic compounds in Rhubarbs using liquid chromatography coupled with electrospray ionization mass spectrometry. J. Am. Soc. Mass Spectr. 18, 82–91.
Sakulpanich, A.; Gritsanapan, W. (2009). Determination of anthraquinone glycoside content in Cassia fistula leaf extracts for alternative source of laxative drug. Int. J. Biomed. Pharm. Sci. 3, 42–45.
Gao, D., Zeng, L., Zhang, P., Ma, Z., Li, R., Zhao, Y. Wang, J. (2016). Rhubarb Anthraquinones Protect Rats against Mercuric Chloride (HgCl2)-Induced Acute Renal Failure. Molecules, 21(3), 298. doi:10.3390/molecules21030298
Nileeka Balasuriya B.W, and Vasantha Rupasinghe H.P. (2011). Plant flavonoids as angiotensin converting enzyme inhibitors in regulation of hypertension. Functional Foods in Health and Disease. 5:172-188
Hoffmann, D. (2003). Medical herbalism: The science and practice of herbal medicine. Rochester, VT: Healing Arts Press.
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