Senna

From the ancient ports of Egypt to the local pharmacy, senna has been - and continues to be - used effectively to relieve digestive problems. The medicinal senna is obtained  from  several  species  of Cassia, such as Cassia italicaCassia angustifolia (Indian Senna), and Cassia acutifolia (Alexandrian Senna).

Quick Facts
General Information
  • Common name(s)Sana, Egyptian senna, Cassia senna, Tinnevelly senna, Wild senna, Indian senna, Desert senna, Alexandrian senna
  • Scientific nameCassia senna
  • Plant typeShrub
  • Native regionNorth Africa/Middle East
  • Main producer(s)India
  • Main Economic UseMedicinal
Senna

Senna gets its name from the famous historical port that first commercialized it. Thought to have originated in regions of northeastern Africa like Nubia and Sudan, senna's fruits and leaves are known to have first been shipped to the Egyptian metropolis and from there to Europe and Asia.

Across its native regions, senna has been touted as a powerful herbal remedy for centuries. Both modern and ancient times have seen the herb used as a natural laxative, as it offers relief from constipation. Thai and Laotian cuisines have also adopted the plant, using the leaves and flowers in some curries.

Medicinal and Nutritional Information

Quick Facts (Medicinal and Nutritional Information)
  • Medicinal actionLaxative
  • Key constituentsAnthraquinones (sennoside)
  • Medicinal rating(4) Very useful plant
  • Safety rankingUse with caution

Health Benefits of Senna

Senna has been used in commercial products since the 1950s due to its potent laxative properties. Thus, senna is used exclusively for:

  • Relieving constipation. Senna irritates the colon, stimulating it and prompting bowel movement.

How It Works

Senna works as a laxative because of its anthraquinones. These anthraquinones include sennosides, aloe emodin, and chrysophanols - and they all have laxative properties. These compounds stimulate bowel movements by irritating the colon.

Senna's laxative action can also be used to clean out the bowels in preparation for a colonoscopy.

Senna Side Effects

The laxative properties of senna can have negative effects on the intestines and cause discomfort, nausea, and stomach cramps. Like other laxatives containing anthraquinones, senna is only intended for short-term relief from constipation - that is, no longer than two weeks at a time - as the bowels can become dependent on it. Rectal bleeding and electrolyte imbalance can be some of the more severe side effects.

Senna Cautions

Those with diarrhea, dehydration, loose stools, abdominal pain, heart disease, Crohn's disease, ulcerative colitis, or hemorrhoids should not take senna. This herb should not be mixed with birth control pills, hormone therapy, warfarin, digoxin, diuretic drugs, horsetail, licorice, or other anthraquinone-containing herbs, such as cascara sagrada. Senna should not be used in children under the age of 12.

How to Consume Senna

Quick Facts (How to Consume)
  • Edible partsFruit, Leaves

Main preparations: Tea, capsules, syrup

Senna remedies are made from the leaves and fruits of the plant, though the leaves seem to be more potent. No matter the preparation, senna intake should not exceed 34 grams per day in adults. As an irritant laxative, it is viewed as the "last resort" for alleviating constipation.

  • Tea. A senna infusion is the most common way to consume to herb. It is sometimes steeped with ginger and cloves.
  • Syrup. Senna syrup is the preparation that tends to be used in younger people thanks to its sweet taste, though senna should not be taken by children under 12.
  • Capsules. Supplements are the surest way to consume a consistent dosage of senna's anthraquinones.

Buying

Quick Facts (Buying)
  • Where to buyBig online retailers, Specialized health stores

Raw and Simply Processed Senna

The plant's availability often depends upon regional factors. As a living shrub, it is more commonly found in areas where it grows naturally, like northeastern Africa and subtropical eastern Asia. Western consumers, however, may be able to find it in garden stores or seed suppliers. Senna leaves are easier to find as a tea in specialized health food stores as well as online.

Senna Supplements

Thanks to recent approval from the FDA, senna supplements are more widely available than ever before, and some major pharmacies stock them with alternative herbal remedies. Health stores may also carry the product, and various online retailers are another option. Supplements may come as powders, granules, tablets, oral infusions, or syrups. Instructions will offer accurate dosage amounts.

Growing

Quick Facts (Growing)
  • Life cyclePerennial
  • Harvested partsLeaves, Fruit
  • Light requirementsFull sun
  • SoilMedium (loam)
  • Soil pH6.6 – 7.3 (Neutral), 7.4 – 7.8 (Slightly alkaline), 7.9 – 8.4 (Moderately alkaline)
  • Growing habitatSubtropical regions

Harvested semi-annually, senna can thrive in a range of conditions and soils, though a good drainage system is necessary. The soil should range from 7.0 – 8.5 on the pH scale, so loams and alluviums are good options. Several hours of bright sunshine daily will allow the shrub to reach its full potential, while irrigation and weeding will keep invading species at bay. To process leaves, plants are cut down and dried in the sun.

Additional Information

Quick Facts (Additional Information)
  • Other usesDye

Plant Biology

  • Classification
    Senna is a member of the Fabaceae family, a classification it shares with some 19,400 other species of flowering plants. Cassia senna, the apothecary term for the herb, is merely a synonym to denote its use in medical compounds. Senna itself is the size of a shrub, growing an average of 6.5 feet (2 m) in height, and boasting branching stems, each bearing four to five leaves. Its flowers are big and yellow, while its fruits are oblong and flat, classified as legume pods.

  • Related Species
    Because senna is largely gathered in the wild, no cultivars have been developed. In addition, no subspecies have been identified. However, the Cassia genus includes different species of senna, all with similar properties and appearance, such as:

    Cassia italica, also called Italian or Port Royal senna, used in natural hair coloring.

    Cassia armata or Desert Senna. Native to Arizona and California, and hardy from Zone 4 to 7.

    Cassia fasciculata (Partridgepea), and C. occidentalis (Coffee Senna) are common roadside weeds in eastern and mid-North America.

    Cassia marilandica, also known as American Senna or Indian Senna.

    Cassia acutifolia or Alexandrian Senna, which include a variety that also grows in the wild: C. obtusifolia L. or Wild Senna.

Economic Data

Senna's powerful flushing ability has been put to use mainly as a source of anthraquinones, the active ingredient in many modern laxatives. In addition, it has seen a rising use in the pharmaceutical industry after the plant was used to isolate resveratrol, a compound of rising importance. Nowadays, the center of senna production is located in India, where it is a major alternative crop with a rapidly increasing demand.

Other Uses

Considered beautiful for its big, yellow flowers, senna is sometimes merely ornamental, found in many gardens in regions where the climate allows. The plant has also been used successfully as a natural hair dye that turns locks blonder.

Bibliography

  • USDA Plants Database, Plant Profile for Cassia Senna
  • Encyclopedia of Herbal Medicine, p. 76
  • Medicinal Plants of the World, p. 298
  • MedlinePlus Herbs and Supplements, Senna
  • British Medical Journal, Standardized Senna as a Laxative in the Puerperium, 1957
  • Pharmacology, Metabolism and pharmacokinetics of anthranoids, 1993; Safety and efficacy of a bulk laxative containing senna versus lactulose in the treatment of chronic constipation in geriatric patients, 1993
  • Useful Plants of West Tropical Africa, Volume 3
  • The vPlants Project. vPlants: A Virtual Herbarium of the Chicago Region, Senna armata
  • Medical Toxicology of Natural Substances
  • Cornell University, Senna, Wild