Senna: A Comprehensive Overview of Pharmaceutical Applications

Written by Emmanuella Ogbonna, BPharm; Reviewed by Danielle Kelvas, MD, for PTcell for Pharmaceutical Industries LL.C

Senna is an important medicinal plant widely used in traditional medicines like Ayurveda, Unani and allopathic medicine. (1) It is mainly used as a laxative and stimulant to treat constipation. (2) There is also a widespread use of senna leaf extracts in the skincare and hair care industry.

This article will examine Senna preparations, their classifications, medicinal uses, extraction techniques, and quality control.

Botanical Classification and Characteristics

Senna is a small herb belonging to a family of plants called Fabaceae. There are roughly 350 species of Cassia around the world. However, because of their laxative effects and readily available Cassia angustifolia (Indian Senna) and Cassia acutifolia (Alexandrian Senna), they are official in many pharmacopoeias. (1) They are the two major cultivated species (2).

About 74% of senna is found in America, 13% in Australia, and 10% in Africa or Madagascar.
(3) A few species are found in Asia and the Pacific Islands.

Senna fruits are green in color and turn black or dark when ripe. Most species have light—to medium-green leaves.

**Major bioactive compounds+*

The major bioactive compounds in senna are its anthraquinone glycosides, such as sennosides (sennosides A, B, C, and D) and flavonoids. (2) These compounds are also responsible for their pharmacological properties, such as antibacterial, antifungal, and antioxidant properties.

Other bioactive compounds in senna include phenolics (rhein, kaempferol, aloe-emodin), terpenes, anthraquinone, saponins, phenolics, cannabinoid alkaloids, 1,8-cineole, caryophyllene, limonene, steroids, volatile oils and cinnamic acid. (4)

The leaves and pods of senna are its most valuable potions as they contain sennoside-A and sennoside-B, which are fundamental for their use as a medicinal plant. (1)

Pharmaceutical Uses of Senna

Senna was primarily used in traditional medicine as a laxative and in managing fever, malaria, pain, and worm infestation. (5) However, in modern medicine, few of these benefits have been confirmed in humans. That said, some potential medicinal uses of senna include:

Treating Constipation

The World Health Organization (WHO) has confirmed the laxative effects of senna. (6) In many countries, senna herb extract is available over the counter for the treatment of occasional constipation. Some health providers also use senna to clear bowels before certain medical tests, like colonoscopies.

Studies have associated the laxative effects of senna medicine with the presence of anthraquinones. (7) These compounds increase the amount of water absorbed from the bowels into the gut, softening stools and facilitating easier passage. (8)

Treat infections caused by bacteria or fungi.

In traditional medicine, senna has been used to treat ringworms, tinea infections, scabies and eczema. (3) Current research revealed that senna extract has also demonstrated significant antimicrobial actions against certain bacteria and fungi. (1) Some researchers have found that Senna alata is primarily effective for this purpose (3).

Boosting Immunity

Senna has immune-enhancing bioactive compounds like antioxidants, vitamins and minerals that boost the immune system and reduce the risk of various diseases, especially respiratory infections. (3)

Treating Fatty Liver Disease

Some studies carried out in animals have found that supplementation with senna leaf can inhibit fatty liver inflammation and fibrosis, which suggests its usefulness in treating fatty liver disease.
(9) Researchers also noticed that senna also reduced total cholesterol and triglyceride levels. (10)

Quality Control and Standardization of Senna

The European pharmacopoeia recommends that the leaflets, pods or standardized dry extract of senna contain between 5.5 to 8.0% of hydroxy anthracene glycosides (calculated as sennoside B). (11)

Quality control (QC) and analysis of senna includes the following assays:
● High-Performance Liquid Chromatography with Ultraviolet Detection (HPLC-UV) — Recommended by the European pharmacopoeia for QC of senna pods and leaflets but not the dry extract
● Liquid Chromatography–Mass Spectrometry (LC-MS)
● Nuclear Magnetic Resonance (NMR)
● Thin layer chromatographic analysis Other quality control tests for senna include: (12)
● Determination of heavy metals (extract should not contain arsenic, and lead, mercury and cadmium content should not be more than 2, 0.1 and 0.2 ppm, respectively)
● Assessment of microbial contamination (Total aerobic bacteria count and total yeast and mould count should not exceed 100 and 1000 cfu/g, respectively).

Regulatory Status and Safety Considerations

The Committee on Herbal Medicinal Products (HMPC), a subset of the European Medicines Agency (EMA), recognizes the use of senna, especially in managing constipation and clearing the bowel before diagnostic examination. (8) However, any applications for the licensing of medicines containing senna ultimately require the final decision of the respective national regulatory authority.

Senna is generally safe when used in the recommended doses and for a limited time. The typical dose for human consumption ranges between 15-30 mg once or twice for less than a week. (13) Long-time use and higher doses can lead to liver injury, weight loss and darkened pigmentation of the colonic mucosa. (13)

Future Prospects of Senna Extract

There is a large market for senna leaf extract. The global market for senna leaf extract is expected to reach more than 120 million USD in 2031 due to the increased use of senna in the treatment of gastrointestinal problems. (14)

Due to its effects on weight loss, senna is now readily included in herbal formulations or supplements. There is also widespread use of senna leaf extracts in skincare and hair care, and researchers have forecasted that consumer demand would rise significantly for its use in the cosmetic industry. (14)

1. Kumar, A., Gupta, A. K., Siddiqui, S., Siddiqui, M. H., Jnanesha, A. C., & Lal, R. K. (2022). An assessment, prospects, and obstacles of industrially important medicinal crop Indian Senna (Cassia angustifolia Vahl.): A review. Industrial Crops and Products, 187(Part B), 115472. 2. Thaker, K., Patoliya, J., Rabadiya, K., Reddy, N. R. R., & Joshi, R. (2023). Senna (Cassia angustifolia Vahl.): A comprehensive review of ethnopharmacology and phytochemistry. Pharmacological Research - Natural Products, 1, 100003. 3. Alshehri, M. M., Quispe, C., Herrera-Bravo, J., et al. (2022). A Review of Recent Studies on the Antioxidant and Anti-Infectious Properties of Senna Plants. Oxidative medicine and cellular longevity, 2022, 6025900. 4. Oladeji, O. S., Adelowo, F. E., Oluyori, A. P., & Bankole, D. T. (2020). Ethnobotanical Description and Biological Activities of Senna alata. Evidence-based complementary and alternative medicine: eCAM, 2020, 2580259. 5. Oladeji, O. S., Adelowo, F. E., & Oluyori, A. P. (2021). The genus Senna (Fabaceae): A review on its traditional uses, botany, phytochemistry, pharmacology, and toxicology. South African Journal of Botany, 138, 1-32. 6. Ikram, A., Khalid, W., Saeed, F., Arshad, M. S., Afzaal, M., & Arshad, M. U. (2023). Senna: As immunity boosting herb against Covid-19 and several other diseases. Journal of herbal medicine, 37, 100626. 7. Bylund, D. B. (2017). Senna. In Reference Module in Biomedical Sciences. Elsevier. 8. European Medical Agency. Sennae folium - herbal medicinal product. 9. Nayan, S. I., Chowdhury, F. I., Akter, N., et al. (2021). Leaf powder supplementation of Senna alexandrina ameliorates oxidative stress, inflammation, and hepatic steatosis in high-fat diet-fed obese rats. PloS one, 16(4), e0250261. 10. Naowaboot, J., & Wannasiri, S. (2016). Anti-lipogenic effect of Senna alata leaf extract in high-fat diet-induced obese mice. Asian Pacific Journal of Tropical Biomedicine, 6(3), 232-238. 11. Çiçek, S. S., Moreno Cardenas, C., & Girreser, U. (2022). Determination of Total Sennosides and Sennosides A, B, and A1 in Senna Leaflets, Pods, and Tablets by Two- Dimensional qNMR. Molecules (Basel, Switzerland), 27(21), 7349. 12. Gritsanapan, W., & Mangmeesri, P. (2018). Standardized Senna alata Leaf Extract. Journal of Health Research, 23(2), 59–64. 13. National Center for Biotechnology Information. Senna. 14. Business Research Insights. Senna Leaf Extracts Market Size, Share, Growth, And Industry Analysis By Type (Capsules/Tablets, Powder, Liquid Syrup) By Application (Food Industry, Haircare Industry, Pharmaceutical Industry, Others), Regional Insights, and Forecast From 2024 To 2031.