Picrorhiza kurroa


No documentation.

Vernacular Name

Hong Len, Ma mo ka la, Bya rgan sug pa, G-ya rug ma, Hu huang line, Hon-len.

NOTE: In Tibetan Medicine a single remedy name will often apply to several plants of the same or sometimes different species.  Selection of plant material is based on the characteristics of the medicinal properties.  Picrorhiza kurroa is identified as four types of plants primarily the Lagotis and Picrorhiza species.  For the purposes of this monograph P. kurroa, is used.


P. kurroa is a small, flowering perennial of the family Scrophulariaceae.  A rhizomatous herb, P. kurroa grows from a hard, light brown rhizome, ranging in size from measures 10cm to 20cm in length.  The oft pubescent leaves of P. kurroa grow from a slender stem, which also has a degree of pubescence.  The leaves are usually no more than measuring 7cm in length and are flat and oval with sharply serrated edges.  During the summer months, P. kurroa produces numerous small, purple flowers which grow axillary panicles.  Each flower grows to be no more than 1cm in length and will usually have a maximum of 20 to 30 flowers per each 20cm long flower spike.

Origin / Habitat

Hong Len as identified as P. kurroa, is a perennial herb, found growing throughout the higher elevations of the Himalayan region particularly from Kashmir to Sikkam.  It is native to these same regions. It is small with long roots that grow primarily in the cracks of mountain rocks [2] at elevations from 2,700m to 4,500m [3].

Chemical Constituents

Contains a number of iridoid glycosides including picroside I, picroside III, kutkoside, minecoside and veronicoside[3] [4] . Also isolated was a ketone identical to apocynin.  Additional constituents include D-mannitol, kutkiol and kutkisterol [5].

Plant Part Used

Leaves, stems, inflorescenses, rhizomes and roots. [1]

Traditional Use

In traditional Tibetan Medicine, many concepts are considered in identifying a diagnosis which is not limited to physical presentation.  For this reason, two individuals exhibiting similar physical symptoms may be treated entirely differently depending upon all aspects of the individual’s life.  In addition, never would a single herb be used alone, but always in combination with other remedies, which may be botanical or mineral in nature.

P. kurroa is used for its cooling properties and is used to treat tsha ba diseases. Tsha ba diseases or conditions are the result of warming which can be  due to taking in too many hot foods, participating in too much exercise, wearing too many clothes and sleeping during the day when the weather is hot [1].  Many factors will affect which specific herb will be used as Hong Len, or as a cooling agent.  These factors include but are not limited to the age of the patient, the patient’s personality, the patient’s lifestyle and the specific organ system in the patient’s body that is affected [6]. In addition, the patient’s present mental state will also affect the diagnosis and treatment [7] .Only a well-trained Tibetan medical practitioner is capable of making the diagnosis and prescribing treatment.


As noted above, in Tibetan medicine, P. kurroa is used for its cooling properties.  It brings balance to systems that have become intensified via the various humours.


In regard to its hepato-protective properties, P. kurroa is similar to Milk thistle, and may have an effect on liver regeneration. A 1992 study demonstrated stimulation of nucleic acid and protein synthesis in rat liver with oral administration of P. kurroa. The authors stated the results were comparable to milk thistle.  There have been over 15 studies conducted in laboratory animals regarding the effectiveness of standardised P. kurroa as a tool in liver health. Studies report P. kurroa beneficial for the liver, including viral hepatitis, and exposure to hepatotoxic chemical agents, including alcohol and acetaminophen [8] [9] [10] [11] [12].

P. kurroa was evaluated as a hepato-protective agent against ethanol-induced hepatic injury in rats [12].  There was also an effect on specific alcohol-metabolising enzymes (aldehyde dehydrogenase, 41%; acetaldehyde dehydrogenase, 52%) in rat hepatocytes. The levels of these enzymes were found to be reduced in the cells following alcohol intoxication.


In a randomised, double-blind placebo controlled trial in patients diagnosed to have acute viral hepatitis (HBsAg negative), P. kurroa root powder, 375mg three times a day, was given for two weeks [11]. P. kurroa was reported to significantly decrease lab values of bilirubin, SGOT, and SGPT as compared to placebo. The time in days required for total serum bilirubin to drop to an average value of 2.5mg% was 75.9 days in placebo compared to 27.44 days in the P. kurroa group. Also, the active principles picroside I, catalpol, kutkoside, and kutkoside 1 were tested for the presence of antihepatitis B virus surface antigen (anti-HBsAg) like activity in vitro [13]. A promising anti-HBsAg like activity was noted which differed from the classical viral neutralisation. P. kurroa also inhibited purified HBV antigens prepared from healthy HBsAg carriers from binding in vitro.

Several studies have reported benefit in patients with asthma when using P. kurroa. In a randomised crossover study using laboratory animals, administration of isolated androsin orally or by inhalation prevented bronchial obstruction induced by the inhalation of allergens, platelet activity factors (PAF), histamine, and acetylcholine [14].It was concluded in this study that asthmatic reactions due to histamine and acetylcholine were not altered by P. kurroa, suggesting that androsin is not a broncholytic agent, but prevents bronchial obstruction. It is suggested that androsin may act by depressing the activity of PAF, which plays a major role in the pathogenesis of bronchial asthma. PAF has been reported to provoke long-term inflammatory responses in the lungs, leading to bronchial hyper-reactivity and subsequent bronchial obstruction. Additionally, histamine release from human polymorphonuclear leucocytes, in vitro, has been reported inhibited by some compounds from P. kurroa that have yet to be identified [15]P. kurroa reportedly stabilises mast cells in vivo, further elucidated by a repeated study in vitro in laboratory animals [16] [17] . This may prove useful as part of an integrative approach in patients with allergic conditions [18].

A one-year clinical study of 20 patients (ages 14-60 years), two with perennial asthma, others with seasonal asthma, was conducted using P. kurroa as a therapeutic agent [19] .The degree of clinical improvement in the patients was measured in terms of reduction in the use of bronchodilators, as evident from the results of pulmonary function tests at regular intervals. The patients had experienced asthma symptoms ranging from five to twenty years. The peak expiratory flow rate (PEFR) was monitored and reported sustained increases for up to twelve months of treatment with P. kurroa. The frequency and severity of asthmatic attacks reduced significantly as treatment progressed. A reduction in bronchodilator use was also observed. One observation of interest is that individuals having specific food allergies developed tolerance to these allergens during the period of treatment, probably due in part to the mast cell stabilisation properties of P. kurroa.

A double-blind, crossover trial with placebo failed to demonstrate significant results, although there was a trend toward improvement in symptoms of asthma [20]. Study design and high dropout rate in this trial may have contributed to the poor results.

Apocynin is a constituent of root extracts of P. kurroa and has been reported to possess anti-inflammatory properties in laboratory animals [21] .Apocynin concentration dependently inhibited the formation of thromboxane A2, whereas the release of prostaglandins E2 and F2 alpha was stimulated. Apocynin inhibited arachidonic acid-induced aggregation of bovine platelets, possibly through inhibition of thromboxane formation. Apocynin was found to inhibit neutrophil oxidative burst in vitro without affecting beneficial activities such as chemotaxis, phagocytosis, and intracellular killing of bacteria [22].

The ability of P. kurroa to heal indomethacin-induced gastric ulcers in mice was compared to a standard drug therapy.  The herb was found to heal the ulcers after three days of treatment post assault by increasing mucus secretions, reducing oxidative stress, and augmenting expressions of cyclooxygenase enzymes [23].

Interaction and Depletions

Interaction with other Herbs

No documentation.

Interaction with Drugs

No documentation.

Precautions and Contraindications

Side effects

No documentation.


No documentation.

Age limitation

No documentation.

Adverse reaction

No documentation.

Read More

  1) Medicinal Herbs

  2) Ayuverda


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  14. Dorsch W, et al. Antiasthmatic Effects of Picrorhiza kurroa: Androsin Prevents Allergen- and PAF-Induced Bronchial Obstruction in Guinea Pigs. Int Arch Allergy Appl Immunol. 1991;95(2-3):128-133.
  15. Langer JG, et al. Clinical Trials on Picrorhiza kurroa. Ind J Pharmacol. 1981;13:98-103.
  16. Pandey BL, et al. Immunopharmacological Studies on Picrorrhiza kurroa Royale Ex Benth Part II: Antiallergic Activity. Ind J Allergy Applied Immunol. 1988;2:21-34.
  17. Panley BL, et al. Immunopharmacological Studies on Picrorrhiza kurroa Royale Ex Benth Par VI: Effect on Anaphylactic Activation Events in Rat Peritoneal Mast Cells. Ind J Physiol Pharmacol. 1989;33:47-52.
  18. Sharafkhaneh A, Velamuri S, Badmaev V, Lan C, Hanania N.The potential role of natural agents in treatment of airway inflammation. Ther Adv Respir Dis. Dec 2007;1(2):105-120.
  19. Yegnanarayanan R, et al. Study of Picrorhiza kurroa (PK 300) in Cases of Bronchial Asthma. Bombay Hos J. 1982;24(2):15-18.
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  21. Engels F, et al. Effects of Apocynin, A Drug Isolated from the Roots of Picrorhiza kurroa, on Arachidonic Acid Metabolism. FEBS Lett. Jul 1992;305(3):254-256.
  22. Simons JM, et al. Metabolic Activation of Natural Phenols into Selective Oxidative Burst Agonists by Activated Human Neutrophils. Free Radic Biol Med. 1990;8(3):251-258.
  23. Banerjee D, Maity B, Nag SK, Bandyopadhyay SK, Chattopadhyay S.Healing potential of Picrorhiza kurroa (Scrofulariaceae) rhizomes against indomethacin-induced gastric ulceration: a mechanistic exploration. BMC Complement Altern Med. 31 Jan 2008;8:3.