Senna Leaves: The Herbal Laxative

HEALTH TALK

Senna (Photo – flickr, mauroguanandi).

Senna extracts are the leaves and fruits of various species of Cassia Senna, Cassia acutifolia, Mecca senna, and Cassia augustifolia. It is widely grown worldwide.

By H. S. Nemr

Source and chemical components

Sennosides A and B are the major components of the Senna extract. They are characterized by the presence of a rhein-aloe emodin aglycone molecule. Other constituents include Sennosides C, D, and free sugars.

Actions

Sennosides A and B release their aglycone component once they are hydrolyzed. The aglycone component is responsible for increasing peristaltic activity in the lower bowel hence producing a laxative action. It is also postulated that Sennosides may exert part of their laxative action through stimulation of prostaglandin E2, leading to stimulation of colonic electrolyte excretion.

Therapeutic and reported folk uses

Senna extracts are widely used as laxatives to relieve constipation or for bowel cleansing prior to diagnostic procedures.

Dosage

2 tablets or capsules at bedtime to manage constipation.

Adverse reactions and precautions

• GI: Abdominal cramps, colic, diarrhea pigmentation of the colon (with excessive use).
• Skin: Dermatitis.
• Metabolic: Hypokalemia (with prolonged use).
• Urologic: Discoloration of urine.

Precautions

The administration of Senna extract or tablets is contraindicated in patients with GI inflammatory conditions or hemorrhoids.

Senna extract or tablets should not be used for longer than one week.

Argentine Senna corymbosa (Photo – commons.wikimedia.org).

Interactions

The administration of Senna extract or tablets should be avoided in patients utilizing Calcium Channel Blockers or Indomethacin.

Points of interest

The abuse of Senna and other stimulant laxatives is a widespread problem for patients with eating disorders and for elderly patients who believe that they must have a daily bowel movement.

H.S. Nemr is a graduate of BAU pharmacy school. He is currently a medication safety officer at Johns Hopkins Aramco Healthcare system.

References

1. Professional’s Handbook of Complementary Alternative Medicines, Springhouse, 2nd edition.
2. Natural drug information, Lexicomp’s Uptodate.com.