Trigonella foenum-graecum

Botany

Trigonella foenum-graecum is an aromatic annual growing up to 60cm (3, 4) and is not unlike lucerne in appearance (5). Native of the waste grounds of the Mediterranean basin, North-eastern Africa and Western Asia (3, 4), it has been cultivated since ancient times (3) and is now days widely cultivated in India, France and Turkey (3, 4).

The leaves are trifoliate and obovate (3, 4); the flowers are pale yellow and pea-like, in leaf axil (3, 4). The pods are curved and sickle-shaped, and there are 10 to 20 angular seeds per pod (3, 4) which are aromatic, yellow-brown, rhomboidal and divided into 2 lobes by a furrow (3, 4, 5).

History

Fenugreek was used in ancient Egypt to treat burns and to promote childbirth (4) and, taken with honey, was used in the treatment of dyspepsia (2, 5), diabetes and rickets (2). Dioscorides’s writings record use in gynaecological problems including vaginitis, vulvitis and uterine infection (4).

Fenugreek has been used traditionally, and is still widely used today, in North Africa, the Middle East and India for convalescence and anorexia, as a febrifuge, to soothe gastritis and gastric ulcers, to induce childbirth and as a galactagogue (4).

In Ayurvedic medicine, fenugreek is used as a general tonic, to relieve many gastro-intestinal ailments, as a galactagogue, and to soothe haemorrhoids and chronic cough (6).

Major Active Constituents

Fenugreek seeds contain 45 to 60% carbohydrates , mainly as galactomannan, a mucilage (1, 2, 3, 7), 20-60% proteins, especially high in the amino-acids lysine and tryptophan, and 4-hydroxyisoleucine, a free amino-acid (3, 7), pyridine alkaloids (trigonelline) (1, 2, 3, 4, 7), steroidal saponins (diosgenin)(1, 2, 7), flavonoids as flavone glycosides (apigenin, luteolin, quercetin) (7).

Actions

Hypoglycaemic (1; 2, 4, 7), hypolipidaemic (1, 2, 4, 7), galactagogue (1; 2; 4; 8), demulcent (1, 2, 4, 8), anti-inflammatory (1, 2, 7), carminative (6).

Pharmacology

Hypoglycaemic activity
Many studies of experimentally induced diabetes in animals and of diabetic humans demonstrate the hypoglycaemic action of fenugreek seeds (2). Both the seed and leaf have properties, but the seed is most studied (1).
Proposed mechanisms of the hypoglycaemic action of fenugreek seeds include insulinotropic activity of 4-hydroxyisoleucine, observed in vitro and in animal studies (9, 10, 11).

Administration of soluble dietary fraction (SDF) of fenugreek seeds significantly improved oral glucose tolerance in DM I and II rats through a decrease in intestinal disaccharidase activity, resulting in decreased glucose absorption. Serum insulin and insulin secretion were not affected by the fenugreek SDF, confirming a hypoglycaemic effect through the inhibition of carbohydrate digestion and absorption (12).

An aqueous fenugreek seed extract induced a dose-dependent activation of intracellular GLUT 4 translocation to the cell surface, independently of insulin, resulting in enhanced glucose uptake in alloxan-induced diabetic mice (13). Another study (14) further demonstrated a marked decrease in blood glucose and a restored expression of pyruvate kinase and phosphoenolpyruvate carboxykinase and an increase in GLUT 4 distribution in skeletal muscles of alloxan-diabetic rats.

Fenugreek as an adjunct therapy has been studied in type I and II rodents in view to reduce dosage of toxic hypoglycaemic drugs. Combination treatments of fenugreek and vanadine showed a return to normal glycaemia and to a restored Na/K pump activity, membrane fluidity and expression and distribution of GLUT 4 in the liver, kidney and heart and protected against ocular histopathological changes (15, 16).

Hypocholesterolaemic and hypolipidaemic activity
Several animal models have shown the hypolipidaemic and hypocholesterolaemic properties of fenugreek. Although a past study pointed to saponins as a main active constituent to explain hypolipidaemic activity (17), recent explanations of the hypocholesterolaemic activity of fenugreek include the reduced re-absorption of cholesterol and bile salts in the intestine.

In a study of the effects of different mucilages in dyslipidaemic rats, galactomannan extracted from fenugreek produced decreased lipid levels in serum, liver and aorta. Mucilage-fed rats showed a decrease in the metabolism of apoB-containing VLDL lipoproteins by the liver (18).

Rats fed 0.5g/kg of soluble dietary fraction of fenugreek showed significant decrease in triglycerides, total cholesterol and LDL cholesterol, and an increase in HDL cholesterol (12).
Isolated 4-hydroxyisoleucine from fenugreek has also shown significant decrease of plasma triglycerides (33%), total cholesterol (22%), and free fatty acids (14%), accompanied by a 39% increase in HDL cholesterol in dyslipidaemic hamsters (11).

Antiulcerogenic activity
A gel fraction of fenugreek demonstrate a significant dose dependant protective effect in aspirin and ethanol- induced ulcers in rats, confirmed by increased gastric mucous production and histological examination (gastric protection in ethanol-induced ulcers was as effective as omeprazole, a proton pump inhibitor, while in aspirin-induced ulcers, fenugreek was as effective as raniditine, a H2 receptor blocker).It is thought that the protective effect is due to polysaccharides. The human extrapolated dosage for this effect is 50-100g/day (19, 20).

Antilithic activity
The inhibition of calcium oxalate kidney stones in rats by fenugreek aqueous extract is significant compared to an untreated control group (21, 22).

Hypoglycaemic activity
A number of small clinical trials studying the hypoglycaemic activity of fenugreek in type II diabetic patients have shown encouraging results, using different fenugreek preparations. Seed powder, ethanol extract and decoction showed activity in both diabetic and norma-glycaemic patients, including transient hyperglycaemia (1); defatted seeds showed activity in diabetic patients, but not in normal subjects and fractions of defatted seeds containing fibre showed activity but not the fractions contains saponins and/or protein (1).

Hypolipidaemic activity
A number of small clinical trials studying the activity of fenugreek in dyslipidaemia have shown encouraging results, using different fenugreek preparations, including sprouted seeds, defatted seeds, and regular seeds (1); these showed a marked trend in decreasing total cholesterol, LDL and VLDL cholesterol and triglycerides. However, HDL cholesterol seems unaffected overall (1).

Indications

Convalescence, anorexia, dyspepsia and inflammatory conditions of the gastro-intestinal tract (gastritis, ulcers, diarrohea) are the main traditional Western medicinal use of fenugreek (1, 2, 3, 4, 8). It is also used topically for external inflammatory skin conditions such as boils, ulcers, abscesses and burns as well as wounds (1, 2, 4, 8). The use in lactation to stimulate flow and production is present in both Western and Ayurvedic medicine (1, 2, 4, 8), often in combination with other herbs (6).

Traditional Ayurvedic use of fenugreek for blood glucose control, backed by existing in vivo and small clinical trials, indicates fenugreek can be useful in the management of diabetes mellitus, type I and II, especially as an adjunct (9, 23); and in hyperlipidaemia (1, 2, 6), although larger randomized clinical trials are necessary to confirm these uses (6).

Contra-indications and Cautions

Fenugreek is generally considered safe and well tolerated (1, 2, 6, 23) with lack of significant harmful adverse effects reported in literature (24).

Allergies
Allergic reactions are rare (2, 25, 26). A cross reactivity in persons allergic to chickpea is possible and persons with asthma can also be susceptible, resulting in wheezing, bronchospasms and angiodoema (2, 26). Do not use in patients with a known allergy.

Other adverse reactions
Doses over 100g daily (a dose well above the therapeutic recommendations) may cause gastro-intestinal symptoms such as diarrohea and flatulence (2, 24). However, a clinical trial demonstrated mild symptoms with doses as low as 25g (25).

Use in pregnancy
Reputation as an abortifacient in traditional Ayurvedic medicine has raised concern for the use of fenugreek during pregnancy, but its use as a foodstuff is widespread, and no adverse event is reported in the literature (24, 25). Typical dietary and therapeutic doses are likely to be safe (25, 2), however the effect of large doses has not been evaluated (2).

Use in lactation
Fenugreek is a traditional galactagogue in both Western and Ayurvedic medicine (1, 2, 3, 4) and is considered compatible with breastfeeding (25). Since 1994, the Indian government supports the use of fenugreek in lactation to enhance nutritional values in infants, as it is rich in iron (25). Methipak, a traditional bittersweet confectionary, is a commonly consumed food by nursing mothers (25).

Herb-drug/nutrient interactions
Frequent consumption of dietary fenugreek or large doses is associated with decrease in iron absorption (2, 24, 25).
Monitor patients taking concomitant hypoglycaemic agents (6, 24) as there is a possible additive effect.
ESCOP notes a potential decreased absorption of drugs taken concurrently with fenugreek seeds due to mucilage content (23).
A theoretical concern exists with warfarin due to the herb’s coumarin content although a placebo controlled study found no interaction in platelet aggregation (1, 2). Fenugreek coumarins are not hydroxylated to form dicoumarol, a compound responsible for increase in bleeding and anticoagulant activity (1).

Cautions
High dose for people with low thyroid activity is not recommended due to a noted inhibition of T4 to T3 conversion by fenugreek intake (1, 2, 27).

Posology

Internally
General prescription - 2-6 ml/day of a 1:2 liquid extract (1, 2, 8).
Lack of appetite -1-6g of powered fenugreek tds before meals (23).
Diabetes -there is a lack of consensus on the appropriate dose. Doses a low as 2g/day of dried seeds are recommended (1, 24) and as high as 50-100g/day in divided doses (2). ESCOP recommend 25g/day as an adjunct therapy.
Hyperlipidaemia -there is a lack of consensus on the appropriate dose - 18g germinated seeds daily (2) or a 100g defatted seeds daily (2); ESCOP recommends 25g seeds or equivalent preparation daily; Bone recommends 2g/day of seeds (1, 25).

The bitter taste may be an issue for treatment compliance (28).

Externally
50g of powered seeds boiled in 250 - 500ml water applied as a warm poultice (2, 8, 23).

References

1. Bone K. 2003. A Clinical Guide to Blending Liquid Herbs. 1st edition. St. Louis: Churchill Livingstone.

2. Braun L, Cohen M. 2007. Herbs and Natural Supplements, An Evidence-based guide. 2nd edition. St Louis: Churchill Livingstone.

3. Van Wijk BE, Wink M. 2005. Medicinal Plants of the World. 1st edition. Pretoria: Briza.

4. Chevallier A. 2001. Encyclopaedia of medicinal plants. 2nd edition. London: Dorling Kindersley.

5. Grieve M. 1973. A Modern Herbal. Revised edition. West Molesley: Merchant Book Company Ltd.

6. Braun L. Fenugreek, Trigonella foenum-graecum. The Journal of Complementary Medicine 2005; (4) 5:77-80.

7. Barnes J, Anderson L, Phillipson JD. 2002. Herbal Medicine – A Guide for Health Care Professionals. London: Pharmaceutical Press.

8. Hoffmann D. 2003. Medical Herbalism. Rochester, Vt: Art Healing Press.

9. Broca C, Gross R, Petit P, Sauvaire Y, Manteghetti M, Tournier M, et al. 4-hydroxyisoleucine: Experimental Evidence of its Insulinotropic and Antidiabetic Properties. The American Journal Of Physiology 1999; 277:617-623.

10. Broca C, Manteghetti M, Gross R, Baissac Y, Jacob M, Petit P, et al. 4-hydroxyisoleucine: effects of synthetic and natural analogues on insulin secretion. European Journal Of Pharmacology, 2000; 390(3):339-345.

11. Narender T, Puri A, Shweta T, Khaliq T, Saxena R, Bhatia G, Chandra R. 4-hydroxyisoleucine: an Unusual Amino Acid as Antidyslipidemic and Antihyperglycemic Agent. Bioorganic and Medicinal Chemistry Letters, 2006; 16(2):293-296.

12. Hannan J M, Ali L, Rokeya B, Khaleque J, Akhter M, Flatt P R, et al. Soluble Dietary Fibre Fraction of Trigonella foenum-graecum (fenugreek) Seed Improves Glucose Homeostasis in Animal Models of Type 1 and Type 2 Diabetes by Delaying Carbohydrate Digestion and Absorption, and Enhancing Insulin Action. British Journal of Nutrition, 2007; 97(3):514-521.

13. Vijayakumar MV, Singh S, Chipa RR, Bhat MK. The Hypoglycaemic Activity of Fenugreek Seed Extract is Mediated through the Stimulation of an Insulin Signalling Pathway. British Journal of Pharmacology 2005; 146(1):41-48.

14. Mohammad S, Taha A, Akhtar K, Bamezai RN, Baquer NZ. In vivo effect of Trigonella foenun graecum on the Expression of Pyruvate Kinase, Phosphoenolpyruvate Carboxykinase, and Distribution of Glucose Transporter (GLUT 4) in alloxan-diabetic rats. Canadian Journal of Physiology and Pharmacology, 2006; 84(6):647-654.

15. Preet A, Siddiqui MR, Taha A, Badhai J, Hussain ME, Yadava PK, Baquer NZ. Long-Term Effect of Trigonella foenum-graecum and its Combination with Sodium Orthovanadate in Preventing Histopathological and Biochemical abnormalities in Diabetic Rat Ocular Tissues. Molecular and Cellular Biochemitry, 2006; 289(12):137-147.

16. Siddiqui M R, Moorthy K, Taha A, Hussain ME, Baquer NZ. Low Doses of Vanadate and Trigonella Synergistically Regulate Na+/K + -ATPase Activity and GLUT4 Translocation in Alloxan-Diabetic Rats. Molecular and Cellular Biochemistry, 2006; 285(1-2):17-27.

17. Al-Habori. Effects of Fenugreek Seeds and its Extracts on Plasma Lipid Profile: a Study on Rabbits. Phytotherapy Research, 1998; 12(8):572-575.

18. Boban PT, Nambisan B, Sudhakaran PR. Hypolipidaemic Effect of Chemically Different Mucilages in Rats: a Comparative Study. The British Journal of Nutrition, 2006; 96(6):1021-1029.

19. Thirunavukkarasu V, Anuradha CV. Gastroprotective effect of Fenugreek Seeds (Trigonella foenum-graecum) on Experimental Gastric Ulcers in rats. Journal of Herbs, Spices and Medicinal Plants, 2006; 12(3):13-25.

20. Pandian RS, Anuradha CV, Viswanathan P. Gastroprotective Effect of Fenugreek Seeds (Trigonella foenum-graecum) in Mice and Rats. Journal of Ethnopharmacology. 2002; 81(3):393-397.

21. Laroubi, A. Prophylaxis effect of Trigonella foenum-graecum L. seeds on renal stone formation in rats. Phytotherapy Research, 2007; 21(10):921-925.

22. Ahsan SK, Tariq M, Ageel AM, al-Yahya MA, Shah AH. Effect of Trigonella foenum-graecum and Ammi majus on Calcium Oxalate Urolithiasis in Rats. Journal of Ethnopharmacology, 1989; 26(3):249-254.

23. European Scientific Cooperative On Phytotherapy. 2003. Monographs: The Scientific Foundations for Herbal Medicine Products. 2nd edition. Exceter, Uk: ESCOP in collaboration with Thieme.

24. Fenugreek (Trigonella foenum-graecum). Natural Standard Monograph. 2008. Basch E et al. Accessed 13 September 2008. <http://www.naturalstandard.com.ezproxy.scu.edu.au/monographs/monoframeset.asp?monograph=/monographs/herbssupplements/fenugreek.asp%3Fprintversion%3Dtrue>

25. Mills S, Bone K. 2005. The Essential Guide to Herbal Safety. St Louis: Elsevier Churchill Lingstone.

26. Patil SP, Rammohan R, Niphadkar P V, Bapat M M. Allergy to Fenugreek (Trigonella foenum-graecum). Annals of Allergy, Asthma & Immunology, 1997; 78(3):297-300.

27. Panda S, Tahiliani P, Kar A. Inhibition of Triiodothyronine Production by Fenugreek Seed Extract in Mice and in Rats. Pharmacology Research, 1999; 40(5):405-409.

28. Pathak P, Srivastava S, Grover S. Development of Food Froducts Based on Millets, Legumes and Fenugreek Seeds and their Suitability in the Diabetic Diet. International Journal of Food Sciences and Nutrition, 2000; 51(5):409-414.

This monograph was authored in 2008 by Helene de la Follye de Joux, a student in Southern Cross University’s Bachelor of Naturopathy programme, and edited by Nena Aleschewski BNat. While the author and editor have strived to cite published information accurately, Southern Cross University will not be responsible for any inaccuracies that may have occurred.

This information is provided for educational purposes only and does not constitute medical advice. If you wish to use herbal medicine as part of your health care, seek the advice of an appropriately qualified practitioner.