Senna

Names and identification

Language	Name
English	Senna
Latin/Botanical	Cassia angustifolia Vahl (syn. Senna alexandrina Mill.)

Key Phytochemical Constituents

• Sennosides A and B (rhein dianthrone glycosides - primary active)
• Sennosides C and D (rhein-aloe-emodin heterodianthrones)
• Rhein and rhein-anthrone (active metabolites)
• Aloe-emodin
• Kaempferol and its glycosides
• Isorhamnetin
• Chrysophanol
• Mucilage and polysaccharides

How does it work?

• Laxative mechanism: sennosides are hydrolyzed by colonic bacteria to release rhein-anthrone, which acts as a local irritant stimulating colonic peristalsis and inhibiting water/electrolyte absorption
• Anthraquinone-mediated antimicrobial action through disruption of bacterial membrane integrity and interference with DNA/RNA synthesis
• Antioxidant mechanism through phenolic and flavonoid constituent scavenging of free radicals, reducing oxidative cellular damage

Which traditional uses are supported by research?

• Laxative efficacy extensively validated through clinical studies and pharmacological research, confirming premier traditional use as a bowel stimulant (Virechana dravya)
• Antimicrobial properties validated against multiple bacterial and fungal strains, supporting broader traditional applications beyond purgation
• Anti-inflammatory properties partially validated through preclinical studies, though this is not the primary traditional indication

What do recent clinical trials show?

• Alshehri MM, Quispe C, Herrera-Bravo J and others 2022. A Review of Recent Studies on the Antioxidant and Anti-Infectious Properties of Senna Plants. Oxidative medicine and cellular longevity. PMID 35154569 · doi:10.1155/2022/6025900
  Documented significant antioxidant and anti-infectious properties of Senna species beyond traditional laxative use, with potential applications in antimicrobial therapy.

2 further claims previously listed here could not be traced to a published paper and have been removed. An absence here means we could not identify the source, not that no work exists.

Recent safety updates

• EMA and WHO recommend use for no more than 1-2 weeks without medical supervision; chronic use may lead to electrolyte imbalance (hypokalemia), melanosis coli, and rarely hepatotoxicity (LiverTox likelihood score D - possible rare cause)
• Severe hepatotoxicity is unusual but documented in cases of chronic overuse; one case of acute liver failure with portal vein thrombosis reported; Cassia angustifolia extract was found not hepatotoxic at doses higher than normal in controlled in vitro/in vivo study

What is it made of?

Key Active Markers

• Rhein
• Glycosides
• Emodin
• Kaempferol
• Isorhamnetin
• Chrysophanol
• Mucilage
• Polysaccharides

Analytical Methods: HPLC fingerprinting, TLC (identity), LC-MS/MS (marker quantification)

Dosage forms and preparation

Dosage Forms: Tablet, Capsule, Tea/Infusion, Syrup, Granules, Churna (powder), Standardized extract tablet

Standard Dosage: 15-30 mg sennosides (calculated as sennoside B) per day for adults; 0.5-2 g leaf powder; 1-2 g pod powder; use for maximum 7-10 consecutive days

Bioavailability: Sennosides are prodrugs — poorly absorbed intact in the small intestine (<5% systemic absorption). Colonic bacteria (Bifidobacterium, Bacteroides) convert sennosides to rhein-anthrone, the active metabolite, which acts locally on colonic mucosa to stimulate peristalsis and electrolyte secretion. Onset of action: 6-12 hours (overnight effect). This colonic-targeted mechanism is therapeutically advantageous.

Optimal Timing: Single dose at bedtime for morning bowel movement (6-12 hour onset); take with adequate water (250 mL minimum)

Standardized Extract: Standardized leaf extract per USP: NLT 6.0% total sennosides (as sennoside B) by HPLC. Pod extract: NLT 2.5% total sennosides. Typical commercial extract: 8-20% sennosides.

Shelf Life: 36 months for standardized extract tablets in blister packaging; 24 months for dried leaf/pod; 18 months for tea bags

Storage: Store below 25 deg C, protected from light and moisture. Sennosides are photolabile — amber or opaque packaging required. RH <60%.

Marker Compounds: Sennoside A, Sennoside B, Rhein, Aloe-emodin, Kaempferol, Isorhamnetin

Extraction Methods

• Aqueous extraction (hot water infusion at 80-90 deg C, 10-15 min)
• Hydroalcoholic extraction (40-60% ethanol)
• Standardized extraction per USP/PhEur monograph
• Spray-drying of aqueous extract for powder form

Synergistic Combinations

• Haritaki (Triphala-based laxative formulations)
• Fennel/Saunf (carminative addition to reduce griping)
• Psyllium husk (bulk-forming + stimulant laxative combination)
• Ginger (reduces nausea and griping associated with senna)