Introduction: 

Plants have been used in various indigenous systems of medicine for ages. Literature survey has revealed potent biological activities of several plants, which are proven through many animal and human studies. 

Kuth is one such indigenous plant found on the Indo-Pakistan border and Jammu and Kashmir, the Himalayan range of Uttarakhand and Himachal Pradesh and the Western Ghats. It grows wildly in China and Pakistan as well. The botanical name of the Kuth plant is Saussurea lappa, also known as S.costus, belonging to the family Asteraceae and is often referred to as costus. It is a perennial herb with purple flowers having a fluffy and feathery appearance. The fruit of kuth is curved, hairy and greyish.^1,2 

Different parts of costus or kuth have been widely used in Ayurveda and Unani forms of medicine since ancient times. The roots are used in relieving fever, cough and stomach ache, while a paste with mustard oil provides relief from pain in the joints, especially during winter. The several traditional uses of kuth promise its great demand in the pharmaceutical industry. Unfortunately, kuth is on the verge of extinction and has been listed in the Red Data Book of Indian Plants.³ 

Nutritional Value of Kuth: 

The bioactive compounds present in kuth are: 

Table 1: Bioactive compounds of kuth⁴ 

Other bioactive compounds include flavonoids, glycosides, steroids, lignans and triterpenes.²             

Properties of Kuth: 

• It may have the property to relieve the spasmodic pain in the stomach. 
• The root of kuth powder may help in decreasing the swelling or tightening of blood vessels during headaches. 
• The paste of root powder and jaggery may help in reducing urine overload in the bladder. 
• Kuth root powder may reduce inflammation. 
• Kuth root powder may restore energy and decrease the general weakness of the body. 
• It might help in decreasing elevated blood glucose levels. 
• It can relieve labour pain by inducing sedation and relaxing smooth muscles. 
• It might help in decreasing the irritation caused by cough and cold. 
• It might help in decreasing the temperature of the body.^1,2,5 

Potential Uses of Kuth for Overall Health: 

Potential use of Kuth in Gastric ulcers 

Anti-ulcer activity of kuth has been discussed by various researchers over a period. Zahara et al., 2019 in their review, discussed the potential of S.lappa. They mentioned that the administration of kuth root extract reduces the acidic secretion in the stomach and increases the movement of food from the stomach to the small intestine (gastric emptying), which results in a noteworthy improvement in ulcers. The herbal formulation UL-409 (mentioned by Madhuri et al., 2012 and Rathore et al., 2020) possesses anti-ulcer activity in the stomach and also contains S.lappa or kuth as a major ingredient. All this research suggests that kuth may have the potential as an anti-ulcer agent, yet more data is required to establish its true extent in human health.^1,2,6  

Potential use of Kuth in Cancer 

The dehydrocostus lactone, a bioactive compound present in the roots of kuth, has demonstrated anti-cancerous activity in various types of cancer. This includes cancerous growth in the regions of the lungs, liver, gastric route, oral route, colon, ovaries, intestines and prostate glands. Rathore et al., 2020 revealed that the anti-cancerous activity of kuth is due to its potential to stop the growth of cancer cells during the cell multiplication cycle. Madhuri et al. 2012 mention a study performed to evaluate the benefit of kuth extract against gastric cancer. During this study, it was found that the extract of kuth, along with chemotherapy, reduced the growth of the cancerous cells. These results indicate that kuth may have potential as an anti-cancer agent, but more clinical data is required to validate its role in humans. ^2,6 

Potential use of Kuth in Cardiovascular Diseases 

The chemical constituents of Kuth, like flavonoids, glycosides, lactones, etc., have beneficial properties that improve the contraction of heart muscles. Rathore et al. in 2020 showed in a study the potential of kuth in a rabbit heart. They measured the changes in the heart rate, contractions and pericardial fluid (fluid in the space around the heart) of a rabbit’s heart after the administration of kuth. The positive results reveal that the property of kuth is similar to that of cardiac protective agents that decrease the risk of heart-related diseases. These findings suggest that kuth may have the potential for heart disease. More research needs to be undertaken in the future to have sufficient data on the protective activity of kuth on the heart.²  

Potential use of Kuth in Relieving Inflammation 

S.lappa or kuth is often prescribed in Korean prescriptions for relieving inflammatory diseases. Zahara et al., 2019 revealed that kuth extract administered in animal models showed anti-inflammatory properties for acute and chronic inflammation. Rathore et al., 2020 also demonstrated that lactones present in the kuth root also showed positive results at different stages of inflammation. The dose of 200mg/kg of kuth root extract showed considerable anti-inflammatory activity when compared with standard drugs like indomethacin. Amara et al., 2017 mentioned that kuth may help in reducing the inflammation related to rheumatoid arthritis, asthma, gastritis and bronchitis. All the above results suggested that kuth may have potential as an anti-inflammatory agent, but further studies are required to validate its role in human health.^1,2,5 

Potential use of Kuth in Epilepsy and Convulsions 

Zahara et al., 2019 in their review article, described that the extract of kuth root has shown its potential in managing epilepsy and convulsions when administered at a dose of 100 to 300 mg/Kg. It was observed that the administration of kuth roots increased the time difference between the two seizures subsequently. It may be because of the presence of the alkaloids, essential oil and 4-hydroxybenzaldehyde (an approved anti-epileptic agent) in kuth root that benefitted in the initiation and occurrence of seizures. These findings were supported by various researchers on different animal models, suggesting that kuth may have some potential in epilepsy and convulsions. Further clinical research is necessary to establish the true extent of the benefits of kuth on human health.^1,2 

Other potential benefits include: 

• Kuth may reduce muscle spasms by lowering the calcium intake (which is responsible for contraction) within the smooth muscle, resulting in muscle relaxation. 
• The administration of kuth root extracts may help in decreasing diarrhoeal stools. 
• Kuth may show a beneficial role in liver function by reducing elevated triglyceride and cholesterol levels. 
• It may also protect liver and kidney cells against the toxicity caused by drugs (like paracetamol). 
• The oral administration of kuth root extract may have potential against various nematodes like roundworms, owing to its anti-parasitic activity.^1,2 

Though studies show the benefits of Kuth in various conditions, these are insufficient and there is a need for further studies to establish the true extent of the benefits of Kuth on human health. 

How to Use Kuth? 

Various parts of kuth are used in different industries. Some of the uses are: 

• It is used as a fragrant oil in the perfume industry. 
• The alkaloids and essential oils present in the roots of kuth make it useful as a pesticide. 
• The powder of the roots is sprinkled over crops as insecticides. 
• The dried leaves are often used as tobacco. 
• It is also used against the heart disease of cattle. 
• Root powder mixed with hair oil might bring lustre to hair. 
• The kuth powder is used during a hair wash to kill lice. 
• It is also used as a dye to colour grey hair black. 
• The flower and feathers of the herb are used as fuel and food for cattle.  
• Local people also prepare a formulation known as Kadu, which is used to counter cough, cold, stomach aches and headaches.^1,3 

One should always consult an Ayurvedic physician before consuming kuth in large quantities or for therapeutic benefits. They will be the best person to prescribe you the correct form and dosage as per your health condition. 

Side Effects of Kuth: 

Kuth, being a medicinal plant, does not cause any harmful effects. Though, there are still some side effects, which include: 

• Kuth oil used in the preparation of perfumes may cause allergic reactions like itching, dryness and rashes. 
• The lactones present in costus or kuth oil may sometimes lead to inflammation of the skin, accompanied by redness and itchiness, often referred to as dermatitis.⁷ 

Precautions to Take with Kuth: 

Despite being a safe medicinal herb, it should always be used in moderation. 

• Though kuth has been used traditionally to cause sedation and decrease pain during labour, its usage by pregnant women should be done in the presence of a registered medical practitioner only. 
• Breastfeeding women, the elderly and children should use kuth and its extract only after consultation with a doctor. 
• People suffering from skin allergies should avoid using perfumes made from kuth oil.   

Interactions with Other Drugs: 

Since there is no sufficient data available on the interaction of kuth with other drugs, further research is required for the same. One must consult the doctor if he or she is on allopathic medication before consuming kuth to avoid drug interactions. 

Frequently Asked Questions: 

References:  

1. Zahara K, Tabassum S, Sabir S, Arshad M, Qureshi R, Amjad MS, Chaudhari SK. A review of therapeutic potential of Saussurea lappa-An endangered plant from Himalaya. Asian Pacific journal of tropical medicine. 2014 Sep 1;7:S60-9. Available from: https://www.sciencedirect.com/science/article/pii/S1995764514602042  

2. Rathore S, Debnath P, Kumar R. Kuth Saussurea costus (Falc.) Lipsch.: A critically endangered medicinal plant from Himalaya. Journal of Applied Research on Medicinal and Aromatic Plants. 2021 Feb 1;20:100277. Available from: https://www.sciencedirect.com/science/article/abs/pii/S2214786120300383  

3. Rawat YS, Oinam SS, Vishvakarma SC, Kuniyal JC. Saussurea costus (Falc.) Lipsch: a promising medicinal crop under cold desert agro-ecosystem in northwestern Himalaya. Indian J. For. 2004;27(3):297-303. Available from: https://link.springer.com/article/10.1007/s10531-004-4365-x 

4. Ayaz M. Use and survival of kuth (saussurea lappa). Pakistan Journal of Forestry. 1996;46:1-4. Available from: http://www.pfi.gov.pk/control_panel/pdf/002_Use_and_Survival_of_Kuth_vol_46_issue_1-4_1996.pdf 

5. Amara U, Khan A, Laraib S, Wali R, Sarwar U, Ain QT, Shakeel S. Conservation status and therapeutic potential of Saussurea lappa: An overview. American Journal of Plant Sciences. 2017 Feb 4;8(3):602-14. Available from: https://www.scirp.org/journal/paperinformation.aspx?paperid=74474 

6. Madhuri K, Elango K, Ponnusankar S. Saussurea lappa (Kuth root): review of its traditional uses, phytochemistry and pharmacology. Oriental pharmacy and Experimental medicine. 2012 Mar;12(1):1-9. Available from: https://link.springer.com/article/10.1007/s13596-011-0043-1. 

7. Gwari G, Bhandari U, Andola HC, Lohani H, Chauhan N. Volatile constituents of Saussurea costus roots cultivated in Uttarakhand Himalayas, India. Pharmacognosy research. 2013 Jul;5(3):179. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3719259/