- Turkish rhubarb
- turkey rhubarb
- Chinese rhubarb
- tai huang
- da huang
For Patients & Caregivers
Bottom Line: Rhubarb acts as a stimulant laxative, but is not safe to use over long periods of time.
Rhubarb is a perennial herb, the stalks of which are consumed as food. The rhizome and roots are used as laxatives and to treat ulcers, constipation, diarrhea, hypertension, immunosuppression, and cancer in Chinese medicine. In laboratory experiments, rhubard showed biological effects, but scientists are still unsure how rhubarb works. Chemicals in rhubarb called anthraquinones cause tumor death in mice implanted with some solid tumors. Lindeyin, a chemical found in rhubarb, was found to reduce pain and inflammation in laboratory animals.
More studies are needed.
- To treat cancer
No scientific evidence supports this use.
- To reduce the severity of side effects from anticancer therapy
One study suggested that a rhubarb extract may reduce side effects associated with radiation therapy in lung cancer patients, but further studies are needed to confirm such effects.
- To relieve constipation
Rhubarb acts as a laxative, although clinical trials have not tested this use.
- As a fever reducer
There is no research to validate this claim.
- To lower high blood pressure
One study in China found that low-dose rhubarb could prevent high blood pressure in pregnancy, but there is no other evidence that rhubarb can lower high blood pressure.
- To suppress the immune system
Laboratory data shows that rhubarb decreases the activity of isolated immune cells.
- To reduce inflammation
No scientific evidence supports this use.
- To treat infections
This claim is not backed by research.
- To treat stomach ulcers
Rhubarb is often used in traditional Chinese medicine to treat gastrointestinal disturbance, but clinical trials have not been done.
Reducing side effects associated with radiation therapy
In this study, 80 lung cancer patients undergoing radiation therapy received a rhubarb extract or placebo for 6 weeks. Side effects associated with radiation therapy, such as cough, shortness of breath, fever and lung function were measured after 6 weeks and 6 months. Patients receiving rhubarb reported decreased side effects and improved lung function. No side effects were reported.
- You are pregnant (Rhubarb may cause stimulation of the uterus and may increase the risk of miscarriage).
- You have hormone-sensitive cancers such as breast, prostate, cervical, and uterine cancers (Rhubarb may have estrogenic activity).
- If you are taking drugs that are substrates of Cytochrome P450 (Rhubarb may reduce the effectiveness of these drugs).
For Healthcare Professionals
Rhubarb, a perennial herb, is cultivated in many parts of the world. The stalks are consumed as food, and the rhizome and root are widely used in Chinese medicine for a variety of conditions including cancer, immunosuppression, constipation, diarrhea, gastrointestinal ulcers, and hypertension (1)(3). The anthraquinones and tannins in rhubarb are thought responsible for its laxative and constipating effects, respectively (4). But human data are limited.
Cytotoxic (5), cytostatic (6)(14) and antitumor effects have been reported in cancer cells in vitro and in mice (1).
A rhubarb extract reduced radiation-induced lung toxicity and increased pulmonary function in lung cancer patients (7).
When used in very small doses the tannin content in rhubarb has a constipating effect. At higher doses, however, the hydrolyzed metabolites of emodin and sennidin stimulate the gastrointestinal tract and produce a laxative effect (4); in vitro tests show suppression of TNF, IL-1, and IL-6 production. The actions of anthraquinones on rheinanthrone that is transformed from sennoside A may promote the purgative effects of sennoside A (16).The anti-inflammatory activity of emodin may mediate rhubarb’s hepatoprotective effects in rats with cholestatic hepatitis (11).
Lindeyin, a phenolic gallylglucoside exhibits analgesic and anti-inflammatory activity in animal models. Catechin, epicatechin, procyanidins, and gallylglucose inhibit hyaluronidase in vitro (10)(12).
Aloe-emodin also possesses anti-proliferative activity, inducing cell cycle arrest in cancer cell lines (6). Anthraquinone extracts of rhubarb were shown to induce cytotoxicity in cancer cell lines (5) and tumor necrosis in mice (sarcoma 37, mammary, and Ehrlich) (1), although this has not been demonstrated in humans.
Another study showed that emodin inhibits human cancer cell invasiveness by specifically antagonizing the adenosine 5’-triphosphate (ATP)-gated Ca(2+)-permeable channel P2X7 receptor (P2X7R) (17).
Yu HM, et al. Effects of rhubarb extract on radiation induced lung toxicity via decreasing transforming growth factor-beta-1 and interleukin-6 in lung cancer patients treated with radiotherapy. Lung Cancer. Feb 2008;59(2):219-226.
In this randomized, double-blind, placebo-controlled study, 80 lung cancer patients undergoing radiation therapy received a rhubarb extract (20 mg/kg daily) or placebo for 6 weeks. Radiation-induced lung toxicity (RILT), pulmonary function, and circulating TGF-beta and IL-6 levels were measured after 6 weeks and 6 months. In the intervention group, decreased RILT, improved pulmonary function, and reduced circulating TGF-beta and IL-6 were detected as compared to the control group, suggesting that rhubarb reduces RILT through attenuation of TGF-alpha and IL-6. No adverse events were reported.
Larger studies are required to determine the mechanism by which rhubarb extracts exert their effects on RILT.