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Kataka

Strychnos potatorum L.f.

Kataka (Strychnos potatorum L.f.) is a plant drug, also called Nirmali, Payah Prasadisa and Chillikavi, from the Loganiaceae family. Not in WHO monographs; recognized in Ayurvedic Pharmacopoeia of India as Kataka (Nirmali); WHO acknowledges natural coagulants for water purification in developing countries.

Key facts
Botanical nameStrychnos potatorum L.f.
FamilyLoganiaceae
OrderGentianales
Pharmacopoeia statusNot in WHO monographs; recognized in Ayurvedic Pharmacopoeia of India as Kataka (Nirmali); WHO acknowledges natural coagulants for water purification in developing countries
Taxon identifiersGBIF 7725922 · Wikidata Q3595916 · NCBI Taxonomy 85835
Names in other languages
SanskritNirmali, Payah Prasadisa
HindiChillikavi, निर्मली (nirmalī)
EnglishClearing nut
TamilKottai, தேத்தாங்கொட்டை, தேற்றா
MalayalamKatakam
TeluguChilla
KannadaKatakam, Tetramabaral
MarathiNirmal
BengaliNirmali
GujaratiNirmali
PunjabiNirmali

Sources: Ayurvedic Pharmacopoeia of India; efloraofindia's Strychnos potatorum page gives Tamil "Thethaan (தேத்தான்)" and "Thethaangkottai (தேத்தாங்கொட்டை)", noting the seeds clear drinking water; Tamil Wiktionary's entry for "strychnos potatorum" gives தேற்றா, and Tamil Siddha suppliers/Siddha writing use தேற்றான் கொட்டை for the seed.; efloraofindia, Strychnos potatorum, gives "Hindi/Sanskrit: Nirmali" (romanised on the page; निर्मली is the standard Devanagari of that name).; efloraofindia, Strychnos potatorum: Tamil "Thethaangkottai (தேத்தாங்கொட்டை)".. How we source.

The evidence at a glance

12papers on this site for this drug, published 1975 to 2025, 11 with a DOI.

  • 1Other clinical studies and reviews
  • 11Laboratory and animal studies

A count is not a conclusion and a tier is a study design, not a verdict. Everything listed here is laboratory or animal work, which does not show an effect in people. Each paper is listed with what it measured on the page below. See the research index for how papers are tiered.

Names and identification

LanguageName
EnglishKataka
Latin/BotanicalStrychnos potatorum L.f.

Key Phytochemical Constituents

How does it work?

  • Water purification via galactomannan- and protein-mediated coagulation and flocculation of suspended particles and microbes
  • Anti-inflammatory and antiarthritic action through inhibition of protein denaturation and membrane stabilization by tannin-rich fractions
  • Proposed nephroprotective effect via antioxidant-mediated protection of renal tubular cells against chemical toxins
  • Proposed antidiabetic mechanism through alpha-glucosidase inhibition

Which traditional uses are supported by research?

These summaries come from the source notes, which do not name the studies behind them.

  • Water purification (Jala-shodhana): traditionally used to purify water. Studies have reported activity as a natural coagulant and antimicrobial agent.
  • Eye health (Chakshushya): traditionally used as eye drops made from Kataka seed water. Research has reported antimicrobial and anti-inflammatory activity.
  • Anti-diarrheal (Atisara-nashaka): traditionally used for diarrhea. Research has reported astringent and antimicrobial activity attributed to tannins.
  • Diabetes (Prameha): traditionally used for prameha. Preclinical studies have reported reduced blood glucose.

What do recent studies show?

Only studies that could be traced to a published paper are listed here. An absence here means we could not identify the source, not that no work exists.

Recent safety updates

  • Seeds have a long traditional use for water purification; unlike Strychnos nux-vomica, S. potatorum contains much lower levels of strychnine
  • Traditional processing (rubbing seeds on stone vessel) leaves minimal residue in purified water; internal medicinal use should follow Ayurvedic dosage guidelines; excessive use may cause astringent-related constipation

What is it made of?

Key Active Markers

  • Tannins
  • Saponins
  • Galactomannan
  • Alkaloids
  • Flavonoids
  • Sterols
  • Glycosides
  • Lignins

Dosage forms and preparation

Dosage Forms: Beeja Churna (seed powder), Anjana (collyrium for eyes), Kashayam (decoction), Capsule, Water purification agent (traditional)

Standard Dosage: 1-3 g seed powder twice daily; Anjana: as per ophthalmologist direction; 30-50 mL decoction; for water purification: 50-150 mg/L turbid water

Optimal Timing: After meals for digestive and ocular health; water treatment: add to water and allow 1-2 hours settling time

Storage: Store seeds and powder in airtight containers at 15-30°C. Protein-based extracts require refrigeration (2-8°C). Protect from insect infestation.

Marker Compounds: Dimorphic acid, Mannose-specific lectin, Cationic polypeptides, Brucine (must be absent, distinguishes from S. nux-vomica), Diaboline, Loganin, Beta-sitosterol

Synergistic Combinations

  • Triphala for eye wash formulations (Netra Prakshalana)
  • Saptamrit Lauha for ophthalmic combination
  • Lodhra for water purification enhancement
  • Neem for water disinfection synergy

Published research

Literature indexed in PubMed that concerns this subject, grouped by study type. A paper appearing here is a record of what has been published, not evidence that the subject works, and laboratory or animal results do not transfer to people. Study titles link to PubMed so you can read the source rather than take our word.

Other clinical studies and reviews1

  1. Yadav KN, Kadam PV, Patel JA and others. 2014. Strychnos potatorum: Phytochemical and pharmacological reviewPharmacognosy reviews. PMID 24600197 · doi:10.4103/0973-7847.125533

Laboratory and animal studies11

  1. Iftikhar H, Akram S, Khalid NU and others. 2025. Deep eutectic solvent-based green extraction of Strychnos potatorum seed phenolics: Process optimization via response surface methodology and artificial neural networkTalanta. PMID 39753082 · doi:10.1016/j.talanta.2024.127443
  2. Nagaraja K, Hemalatha D, Ansar S and others. 2023. Novel, Biosynthesis of Palladium Nanoparticles using Strychnos Potatorum Polysaccharide as a Green sustainable approach; and their effective Catalytic Hydrogenation of 4-NitrophenolInternational journal of biological macromolecules. PMID 37739284 · doi:10.1016/j.ijbiomac.2023.126983
  3. Abirami A, Sinsinwar S, Rajalakshmi P and others. 2022. Antioxidant and cytoprotective properties of loganic acid isolated from seeds of Strychnos potatorum L. against heavy metal induced toxicity in PBMC modelDrug and chemical toxicology. PMID 31645139 · doi:10.1080/01480545.2019.1681445
  4. Nagaraja K, Rao KM, Hemalatha D and others. 2022. Strychnos Potatorum L. Seed Polysaccharide-Based Stimuli-Responsive Hydrogels and Their Silver Nanocomposites for the Controlled Release of Chemotherapeutics and Antimicrobial ApplicationsACS omega. PMID 35474817 · doi:10.1021/acsomega.2c00131
  5. Neelamkavil SV, Thoppil JE. 2015. Genotoxic assessment of calcium hypochlorite and Strychnos potatorum Linn. seeds-two commonly used water purifying agentsReviews on environmental health. PMID 25411981 · doi:10.1515/reveh-2014-0066
  6. Kagithoju S, Godishala V, Nanna RS. 2015. Eco-friendly and green synthesis of silver nanoparticles using leaf extract of Strychnos potatorum Linn.F. and their bactericidal activities3 Biotech. PMID 28324525 · doi:10.1007/s13205-014-0272-3
  7. Biswas A, Chatterjee S, Chowdhury R and others. 2012. Antidiabetic effect of seeds of Strychnos potatorum Linn. in a streptozotocin-induced model of diabetesActa poloniae pharmaceutica. PMID 23061291
  8. Patil UJ, Savali AS, Jirankali MC. 2011. Antianaphylactic and mast cell stabilization activity of Strychnos potatorum Linn. seedPharmacognosy research. PMID 22022171 · doi:10.4103/0974-8490.85011
  9. Ekambaram S, Perumal SS, Subramanian V. 2010. Evaluation of antiarthritic activity of Strychnos potatorum Linn seeds in Freund's adjuvant induced arthritic rat modelBMC complementary and alternative medicine. PMID 20939932 · doi:10.1186/1472-6882-10-56
  10. Sanmugapriya E, Venkataraman S. 2006. Studies on hepatoprotective and antioxidant actions of Strychnos potatorum Linn. seeds on CCl4-induced acute hepatic injury in experimental ratsJournal of ethnopharmacology. PMID 16388923 · doi:10.1016/j.jep.2005.10.028
  11. Singh H, Kapoor VK, Manhas MS. 1975. Investigation of Strychnos spp. III. Study of triterpenes and sterols of Strychnos potatorum seedsPlanta medica. PMID 1208692 · doi:10.1055/s-0028-1097877

Reference lists that include it

Saponins, Tannins

Reviewed by Dr. Awadesh Pratap Singh, BAMS, on 11 October 2026. What that review covered.

Consult a qualified vaidya before acting on anything here. Ayurvedic practice is prescribed to a person, not to a condition: the same dravya is given, withheld or substituted depending on your constitution, your agni, the season and what else you are already taking. A page cannot know any of that. Self-prescribing from a reference is how the wrong preparation, the wrong dose or the wrong anupana gets used.

Educational reference only. Nothing on this page is medical advice, a diagnosis, or a recommendation to take anything. Traditional uses and research findings are reported as published, not as claims about what any product does. If you take prescribed medication, raise any interaction with the prescriber rather than acting on a page. See our editorial standards.