Senna
(Cassia angustifolia)

Description

Senna is a perennial plant that grows in rich soils in Southern Arabia, India and the United States. The herb is traditionally used for Constipation.

Herbal Uses

Senna leaf is stated to possess cathartic (laxative) properties), (the leaf has greater activity than the fruit) and is traditionally used for Constipation.

Suggested Intakes

Part of the herb used: Leaves (or pods).
Leaf powder 0.5-2.0g daily.

Supplemental Uses

Laxative:
Senna is recommended for the relief of occasional or non-persistent Constipation. The laxative action of the anthraquinone-containing compounds of senna are well documented. The purgative (laxative) action of the sennosides is now fairly well understood. Sennosides are hydrolysed by the intestinal bacteria and then reduced to give the active compound (anthrone).

Sennosides A and B and their metabolites are reported to act on the large intestine, accelerating colonic transport. These compounds also encourage the secretion of water into the colon (1). Senna acts approximately 8-10 hours after being taken (2).

Nitric oxide synthetase may also be involved in senna-induced fluid secretion and Diarrhoea (3,4).

When compared to conventional treatments, senna has been shown to be more effective as a laxative (5,6).

Liver protection:
Some studies have shown that glycosides contained within senna and related plant species have antihepatotoxic activity.

Safety and Precautions

Senna may cause mild abdominal discomfort (cramps).

Senna is not recommended for prolonged use as a laxative. (Long term use upsets water and electrolyte balance).

Senna should not be taken by those with intestinal obstruction (ileus) or undiagnosed abdominal symptoms.

It is recommended that the intake of sennosides should be no more than 15mg from a single dose (2).

Senna may cause a harmful reddening of the urine.

Pregnant and lactating women should consult with a qualified health professional before taking senna, due to a lack of safety data during this time.
Senna is not recommended for use by children.

NB The use of non-standardised senna preparations should be avoided, since their effect will be variable and unpredictable.

Interactions and Contra-Indications

Individuals with IBS and IBD must exercise care when taking senna.
Senna may interfere with cardiac glycosides (such as digoxin).
Senna may potentiate anticoagulant therapy by reducing the absorption of Vitamin K in the gut.

References

1. "Herbal Medicines", CA Newall, LA Anderson, JD Phillipson, The Pharmaceutical Press, 1996.
2. "Herbal Drugs and Phytopharmaceuticals", N Grainger Bissett, Medpharm, 1994.
3. Eur J Pharmacol, 1996, 301; 1-3:137-142.
4. Eur J Pharmacol, 1997, 323;1:93-97.
5. J Pain Symptom Manage, 1998, 15; 1:1-7.
6. Pharmacology, 1993, 47 supply; 1:253-255.