A Review on: Pharmacological action of Fenugreek

Abstract

A fenugreek seed is one of the most ancient medicinal herbs. Trigonella foenum graceum is traditional herbs belong to family Leguminosae. The seed and leaves are well known medicinal applications. It is native to the eastern Mediterranean but is cultivated worldwide. This plant has medicinal alkaloids, steroid compounds, and sapogenins and many uses have been mentioned for this plant in traditional medicine. It is also containing protein, fats and fibre. This plant has been used to ease childbirth, to aid digestion, and as a general tonic to improve metabolism. Trigonelline is considered as the most important metabolite of fenugreek, which is very effective in treating diabetes and decreasing blood cholesterol. Important chemical constituent of Fenugreek seeds including steroidal sapogenins, Diosgenin constituents has been found in the oily embryo of fenugreek seeds. Pharmacological action of fenugreek are antioxidant action, gastroprotective activity, appetite stimulation and antirheumatism. Many studies have been performed on the therapeutic effects and identification of chemical compounds of this plant. In this article, the most important biological effects and reported compounds about fenugreek seed are reviewed and its therapeutic applications are investigated.

Keywords

Hypoglycemia, Anticarcinogenic, Hypocholesterolemia, Antibacterial & Antifungal, Antilipidemia, Antioxidant.

Introduction

Fenugreek seeds is one of the most ancient medicinal herbs. It is one of the oldest known medicinal plants which has been documented in ancient herbal history. (Table 1) Fenugreek is an annual plant belongs to the family Fabaceae (Leguminosae). The biological name of fenugreek is Trigonella foenum graecum. The fenugreek seed is the famous spices in human food. The fenugreek seeds and green leaves are used in food as well as in medicinal application that is the old practice of human history. Fenugreek is a aromatic, (Table 2) 30-60 cm tall, annual herb, cultivated throughout the country. (Figure 1, 2) A nearly smooth erect annual. Stipules not toothed. Leaflets 2-2.5 cm long, oblanceolate-oblong, toothed. Flowers 1-2, axillary, sessile. Calyx-teeth linear. Corolla much exserted. Pod 5-7.5 cm long, with a long persistent beak, often falcate, 10-29 seeded, without transverse reticulations. [1-3] dried seeds have been traditionally used in India, China, Egypt and in some parts of Europe for their beneficial health effects as anti-inflammatory, insulinotropic, and rejuvenating effects The seeds have been used to increase the flavoring and color and modifies the texture of food materials. The fenugreek seeds have many medicinal properties such as hypocholesterolemic, lactation aid, antibacterial, gastric stimulant, for anorexia, antidiabetic agent, galactagogue, hepatoprotective effect and anticancer. These beneficial physiological effects of fenugreek seeds including the antidiabetic and hypocholesterolemic effects are mainly attributable to the intrinsic dietary fiber constituent which have promising nutraceutical value [4-6]. The fenugreek seeds are well known for its fiber, gum, other chemical constituents, and volatile contents. The fenugreek seeds containing dietary fiber which is responsible for the changes the texture of food. It is also used as food stabilizer, adhesive, and emulsifying agent due to its high fiber, protein, and gum content. The protein of fenugreek seed is found to be more soluble at alkaline pH [7]. The seed of fenugreek is having beneficial influence on digestion and could modify the food. It has been used also to promote labor before delivery during Greek period. Fenugreek seeds can be used to treat Lymphedema (oedema of the legs) according to Chinese traditional medicine (Figure 3).

Figure 1: Leaves of Fenugreek.

Figure 2: Seeds of Fenugreek

Figure 3: Pharmacological action of Fenugreek.

Table 1 : Scientific classification of Trigonella foenum graecum.

Table 2 : Chemical constituents of fenugreek seeds [8,9].

Phytochemistry

The seed is a good source of calcium, minerals, iron, β-carotene and several vitamins like vitamins A and D. It is rich source of dietary fiber. It is consisting of free amino acids; 4-hydroxyisoleucine, lysine, histidine, and arginine (25.8%), protein (20-30%), moisture (11.76%), fat (6.53%), crude fiber (6.28%), ash content (3.26%) and energy (394.46 Kcal/100 g seed). Fenugreek seeds also contains lecithin, choline, minerals, B. Complex, Phosphates, and Para-Amino Benzoic acid (PABA). In addition, the main chemical compounds in fenugreek are saponins, fenugreekine, trigonelline, coumarin, scopoletin, phytic acid and nicotinic acid. In (Table 3) Important chemical constituent of Fenugreek seeds including steroidal sapogenins, Diosgenin constituents has been found in the oily embryo of fenugreek seeds. There are two furastanol glycosides, F-ring opened precursors of diosgenin that have been reported in fenugreek also as hederagin glycosides. The stem of the fenugreek plant containing Alkaloids such as trigocoumarin, nicotinic acid, trimethyl coumarin and trigonelline. The fenugreek seeds also containing 28%mucilage. The stem of the fenugreek plant containing yellow color substance. Fenugreek seeds also contains, 6–7% fat and 58% carbohydrates of which about 25% is dietary fibers. Fenugreek is also a rich source of iron, containing 33 mg/100 g dry weight. It provides natural food fiber and other nutrients required in human body. [8,9]

Table 3 : Morphology of the fenugreek seeds [2,3].

According to AYUSH system, fenugreek seed are used in:-

According to Ayurveda and Unani system of medicine, fenugreek seeds are used in different ways

1. Fenugreek seeds are rich in vitamin E and is one of the earliest spices known to man.as preservative and adds to pickles.

2. Fresh fenugreek leaves are beneficial in the treatment of indigestion, flatulence, and a sluggish liver.

3. The dried leaf of the fenugreek is used as a quality flavor for meat, fish, and vegetable dishes.

4. An infusion of the leaves is used as a gargle for recurrent mouth ulcers. A gargle made from the seeds is best for ordinary sore throat.

5. Fresh Fenugreek leaves paste applied over the scalp regularly before bath helps hair grow, preserves natural color, keeps hair silky and cures dandruff.

6. Fenugreek seeds made in gruel, given to nursing mothers increase the flow of milk.

7. Topically, the gelatinous texture of fenugreek seed may have some benefit for soothing skin that is irritated by eczema or other conditions. It has also been applied as a warm poultice to relieve muscle aches and gout pain.

8. Fenugreek seeds reduces the amounts of calcium oxalate in the kidneys which often contributes to kidney stones. In animal studies, fenugreek appeared to lessen the chance of developing colon cancer by blocking the action of certain enzymes.

9. Traditional Chinese herbalists used it for kidney problems and conditions affecting the male reproductive tract.

10. Fenugreek is currently used as a source of the steroid diosgenin, one of its active constituents from which other steroids can be synthesized.

Health benefits of fenugreek seeds and leaves

33 Help control diabetes

33 Stimulates breast milk production

33 Cures constipations

33 Cures joint pains

33 Balance cholesterol level

33 Improves heart health.

33 Fights the flu and colds.

33 Reduce menstrual discomforts.

Pharmacological action of Fenugreek

Fenugreek is known to have several pharmacological effects such as hypoglycemic, antilipidemic activities[4,5]. However, the exact mechanism of action is still unclear. Furthermore, this plant has an antioxidant action[6], gastroprotective activity [7] appetite stimulation [8] , and antirheumatism[9].

Hypoglycemic action

Diabetes melllitus is a chronic metabolic disorder characterized by chronic hyperglycemic either because the pancrease does not produce enough insulin or peripheral target tissue are unable to respond to the normal concentration of insulin [10,11].it is a major cause of morbidity and mortality with an increasing prevalence and the fastest growing disease worldwide [12,13]. Diabetes is a major health concern, and its burden is increasing globally. Herbal medicine plays an important role in treatment of diabetes [14,15]. Fenugreek seeds, leaves and extracts had been used as an anti-diabetic [16].

Mechanisms for these effects have not been fully elucidated. Fenugreek seed contain 45.4% dietary fiber, and the gum is composed of galactose and mannose. The latter compounds are associated with reduced glycemic effect. The hypoglycemic effect of fenugreek has been documented in humans and animals with type 1 and 2 diabetes mellitus [17]

Anticarcinogenic action

Cancer is one of the leading causes of mortality worldwide. Many reported studies have shown the protective effect of fenugreek seeds in experimental models of cancer using cell lines[18]. Consumption of fenugreek was accompanied with decreased polyamines content in tumor tissue [19] Fenugreek seed extract significantly inhibited 7,12-dimethylbenz(a)anthracene-induced mammary hyperplasia and reduces its incidence in rats and advised that anti-breast cancer protective effect of fenugreek could be due to increased apoptosis [20]. According to the investigation treatment with fenugreek extract showed growth inhibitory effects on breast, pancreatic and prostate or immortalized prostate cells remained unaffected. Inhibition of cancer cell growth by Fenugreek is a attributed to its ability to induce death of cell, despite simultaneous upregulation of growth stimulatory pathways in normal cells [21].

Hypocholesterolemic action

The abnormal deficiency of cholesterol level in blood is known as hypocholesterolemic problem. The oral administration of methanolic and aqueous extracts of seeds at a dose of 1gm/kg body weight resulted in hypoglycemic effect in mice [22]. Fenugreek seeds contain the large amount of fiber galactose and mannose are the main composition of gum. The latter compounds are associated with reduced cholesterolemia [23]. Fenugreek extract has been investigated for its effects on blood lipid, and in experimental rats with diabetes .The streptozotocin-induced diabetic rats were administrated by oral intragastric intubation separately with low dose, middle dose, and high dose of fenugreek extract, and Metformin HCl for about one and half month(6 weeks). As compared to diabetic group, rats treated with fenugreek extract had lower triglycerides, total cholesterol, and higher HDL cholesterol in a dose-dependent manner [24]

Antibacterial & antifungal action

The antibacterial and antifungal role of fenugreek has recently been shown. Plant derived compounds with antibacterial and antifungal activities have been identified and reviewed[25-,29].An aqueous extracts from various plant parts of fenugreek in various solvent include methanol, petroleum ether and ethyl acetate fractions of the aerial parts and determine their action against fungal stains such as Fusarium graminearum, Botrytis cinerea, Alternaria sp., Rhizoctonia solani and Pythium aphanidermatum. All parts of the fenugreek plant showed antifungal potential and the magnitude of effect varies with plant parts species of fungus. Fenugreek is an important source of biologically active compounds useful for developing better and novel antifungal drugs [30]. Fenugreek dried seed are known for their valuable antibacterial property. Fenugreek is rich with a wide variety of metabolites such as tannins, alkaloids, flavonoids, terpenoids and glycosides which are known to have antimicrobial properties [31].Various investigators have also showed effectiveness of Trigonella extracts against Helicobacter pylori [32-34].In 0ne study, honey samples with highest antibacterial activity against Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus shown maximum pollens from Trigonella, among other plants [35].

Antilipidemic action

Abnormalities in the lipid metabolism are associated with dyslipidemia, obesity, diabetes, cardiac diseases, inflammation, and their associated disorders [36]. Current treatment of dyslipidemia, obesity, and related metabolic disorders includes various drugs which causes untoward side effects and inflict economic burden [37,38].

Fenugreek seeds have been historically used for the treatment of various chronic human diseases. The studies concerned with application of fenugreek seeds in diabetes, dyslipidemia and obesity support this hypothesis [39-41]. Fenugreek showed lower serum TG and total cholesterol and hepatic lipid concentrations [42-44]. Mechanism-based studies on its efficacy in the prevention and management of dyslipidemia and obesity-related complications do not exist. Because fenugreek seeds are being used as a condiment and are known to have health benefits, novel thermostable extract of fenugreek seeds (TEFS) is used to deduce the hypolipidemic effect, 3T3-L1 cells and HepG2, human hepatoma cell line were used as in vitro models [45,46].

Antioxidant action

Human consume a lot of oxygen to live and survive, to derive energy by the oxidation of food molecules. The excessive production of oxidants in body is normally taken care of by the native antioxidant mechanism; however, in certain conditions these mechanisms become overwhelming for the cells leading to inflammation, tissue damage and disease [47]. Fenugreek leaves reduces oxidative stress in streptozotocin-induced diabetic rats. The antioxidant effect, determined by measuring thiobarbituric acid-reactive substances (TBARS) and reduced glutathione (GSH) levels, and activities of catalase on the one hand significantly lowered lipid peroxidation and, on the other hand significantly increased the antioxidant system [48].

Conclusion

Trigonella foenum graceum has been used for treating and preventing in different diseases from ancient times. It is AYUSH medicine. The conducted pharmacological studies also have confirmed many of these traditional applications and have shown clearly therapeutic value of this plant and abilities of the traditional medicine. Fenugreek seed has a significant antidiabetic effect. It can decrease the absorption of sugar in the gastrointestinal tract and stimulate insulin release, resulting in lowering the blood sugar in diabetic patients. It is different medicinal importants such as inflammation, loss of appetite, upset stomach, gastritis, atherosclerosis, and hypertension. Also used in another condition such as Breast-feeding women sometimes use fenugreek to promote milk flow. It is consisting of high level of iron and can be used for iron-deficient patients. Fenugreek seed used for kidney complications and some other toxicities. It also containing antioxidant activity and it seems that antioxidant property of this plant is one of the main effective factors in creating effects of fenugreek. The antioxidant property of the plant has been attributed to the presence of many active phytochemicals, including flavonoids, plant sterols, vitamins, cumarins, terpenoids, carotenoids, curcumins, lignin, and saponin. However, the phenolic compounds have had the highest contribution in this effect. So, there has been a significant correlation between the polyphenolic components present in the extract and its antioxidant activity. Medicinal plants—because they contain antioxidant compounds, bioactive compounds, phenols, flavonoids, and anthocyanin—have been shown to counteract these conditions and are capable of providing drug supply in complementary medicine. A lot of these plants have previously been used for preparation of new drugs or have shown promising results. Therefore, fenugreek, which possesses phenolic compounds and antioxidant activity should have the ability to counteract these situations and might be a good candidate for a herbal drug.

References

1. Basch E, Ulbricht C, Kuo G, Szapary P, Smith M. Therapeutic applications of fenugreek. Altern Med Rev. 2003;8: 20-27.
2. V.A Parthasarathy, K. Kandinnan, V.Srinivasan(ed)."Fenugreek". Organic Spices. New India Publishing Agencies. 694.
3. Srinivasan K. Fenugreek (Trigonella foenum graecum): A review of heath beneficial physiological effects. Food Rev Int. 2006;22(2):203-224
4. Sharma RD, Raghuram TC, Rao NS. Effect of fenugreek seeds on blood glucose and serum lipid in type 1 diabetes. Eur J clin nutr. 1990;44:301-306
5. Ajabnoor MA, Tilmisany AK. Effect of Trgonella foenum-graecum on blood glucose levels in normal and alloxan-diabetic mice. J Ethnopharmacol. 1998;22:45-49.
6. Belguith-Hadriche O, Bouaziz M, Jamoussi K, El Feki A, Sayadi S et al. Lipid-lowering and antioxidant effects of an ethyl acetate extract of fenugreek seeds in high-cholesterol-fed rats. J Agric Food Che. 2010;58(4):2116-2122.
7. Pandian RS, Anuradha CV, Viswanathan P. Gastroprotective effect of fenugreek seeds (Trigonella foenum graecum) on experimental gastric ulcer in rats. J Ethnopharmacol. 2002;81:393-397.
8. Max B. This and That: The essential pharmacology of herbs and spices Trends. Pharma Sci. 1992; 13:15-20.
9. Suresh P, Kavitha ChN, Babu SM, Reddy VP, Latha AK. Effect of ethanol extract of Trigonella foenum graecum (Fenugreek) seeds on Freund's adjuvant-induced arthritis in albino rats. Inflamm. 2012; 35(4):1314-1321.
10. E.Yibru, M. Menon, Y. Belayneh, D.Seyifu,"The effect of Coriandrum sativum seed extract on hypergycemia,lipid profile and renal function in streptozotocin induced type-2 diadetes Swiss albinonmice," Int J Health Sci Res. 2015;5(7):166-177.
11. Tadesse B. Antidiabetic activity and phytochemical screening of crude extracts of Stevia rebaudiana Bertoni and Ajuga remota Benth grown in Ethiopia on alloxan-induced diabetic mice (Doctoral dissertation, aau). AAU Institutional Repository. 2008.
12. Asssefa. F. Effect of combined aerobic and resistance exercises on blood glucose level and risk factor in male type-2 diabetic patients residing in Haramaya University main campus and its surrounding (Doctoral dissertation), Haramaya University, 2013.
13. Kumar K, S Kumar, A Datta, and A. Bandyopadhyay, "Effect of Fenugreek seeds on glycemia and dyslipidemia in patients with type-2 diabetes mellitus," Int J Med Sci Public Health. 2015;4(7):997-1000.
14. Bailey CJ, Day C. Traditional plant medicines as treatments for diabetes. Diabetes Care. 1989;12:553-564.
15. Jarald E, Joshi SB, Jain D. Diabetes and Herbal Medicines. Iran J Pharmacol Ther. 2008;7(1): 97-106.
16. Bawadi HA, Maghaydah SN, Tayyem RF, Tayyem RF. The Postprandial Hypoglycemic Activity of Fenugreek seed and seeds' Extract in Type-2 Diabetes: A Pilot Study. Pharmacogn Mag. 2009; 5(18): 134-138.
17. K.T Roberts. The potential of fenugreek (Trigonella foenum-graecum) as a functional food and nutraceutical and its effect on glycemia lipidemia. J Med Food. 2011;14(12):1485-1489.
18. A. Amin, A.Alkaabi, S. Al-Falasi, S.A Daoud. Chemopreventive activities of fenugreek against breast cancer. Cell Biol Int. 2001;29:687-694.
19. Zhilenko VV, Zalietok SP, Klenov OO. Effects of fenugreek on the growth of different genesis tumors. Lik Sprava. 2012;(5):133-139.
20. S.K. Verma, S.K Singh, A. Mathur. In vitro cytotoxicity of Calotropis procera and Trigonella foenum-graecum against human cancer cell lines. J Chem Pharm Res. 2010;2:861-865.
21. S. Shabeer, M. Sobolewski, R.K. Anchoori, S. Kachhap, M. Hidalgo, et al. Fenugreek: a naturally occurring edible spice as an anticancer. Cancer Biol Ther. 2009;8:272-278.
22. T. Zia, S.N. Hasnain, S.K. Hasan. Evaluation of the oral hypoglycemic effect of Trigonella foenum-graecum L.(methi) in normal mice. J. Ethnopharmacol. 2001;75:191-195.
23. K.T. Roberts. The potential of fenugreek (Trigonella foenum-graecum) as a functional food and its effects on glycemia and lipidemia. J Med Food. 2011;14(12):1485-1489.
24. W.L. Xue, X.S. Li, J. Zhang, Y.H..Liu, Z.L. Wang, et al. Effect of fenugreek extract on blood glucose, blood lipid and hemorheological properties in streptozotocin-induced diabetes rats. Asia Pac J Clin Nutr. 2007;1:422-426.
25. Ahmad I, Beg AZ. Antimicrobial and phytochemical studies on 45 Indian medicinal plants against multi-drug resistant human pathogens. J Ethnopharmacol. 2001;74:113-123.
26. Aqil F, Ahmad I. Antibacterial properties of traditionally used Indian medicinal plants. Method Find Exp Clin Pharmacol. 2007; 29:79-92.
27. Gangoué-Piéboji J, Eze N, Djintchui AN, Ngameni B, Tsabang N, et al. The in-vitro antimicrobial activity of some medicinal plants against β-lactam-resistant bacteria. J Infect Dev Ctries. 2009;3:671-680.
28. Khodaie L, Delazar A, Lotfipour F, Nazemiyeh H. Antioxidant and antimicrobial activity of Pedicularis sibthorpii Boiss and Pedicularis wilhelmsiana Fisch ex. Adv Pharmaceut Bull. 2012;2:89-92.
29. Rabe T, van Staden J. Antibacterial activity of Sauth Africa plants used for medicinal purpose. J Ethnopharmacol. 1997;56:81-87.
30. R. Haouala, S. Hawala, A. El-Ayeb, R. Khanfir, N. Boughanmi. Aqueous and organic extracts of Trigonella foenum-graecum L. inhibit the mycelia growth of fungi. J Environ Sci. 2008;20:1453-1457.
31. Khorshidian N, Asli M, Arab M, Mortazavian A M, Mirzaie A. Fenugreek: potential applications as a functional food and nutraceutical. Nutri Food Sci Res.2016;3:1-5.
32. O’Mahony R, Al-Khtheeri H, Weerasekera D, Fernando N, Vaira D, et al. Bactericidal and anti-adhesive properties of culinary and medicinal plants against Helicobacter pylori. World J Gastroenterol. 2005;11(47):7499-7507.
33. Randhir R, Lin YT, Shetty K. Phenolics, their antioxidant and antimicrobial activity in dark germinated fenugreek sprouts in response to peptide and phytochemical elicitors. Asia Pac J Clin Nutr. 2004;13:295-307.
34. Randhir R, Shetty K. Improved alpha-amyase and Helicobactor pylori inhibition by fenugreek extracts derived via solid-state bioconversion using Rhizopus oligosporus. Asia Pac J Clin Nutr. 2007;16:382-392.
35. Mercan N, Guvensen A, Celik A, Katircioglu H. Antimicrobial activity and pollen composition of honey samples collected from different provinces in Turkey. Nat Prod Res. 2007;21:187-195.
36. Lee CH, Olson P, Evans RM. Minireview: lipid metabolism, metabolic diseases, and peroxisome proliferator-activated receptors. Endocrinol. 2003;144: 2201-2207.
37. Garg A, Simha V. Update on Dyslipidemia. J Clin Endocrinol Metab. 2007;92:1581-1589.
38. Yanovski SZ, Yanovski JA. Obesity. N Engl J Med. 2002;346:591-602.
39. Basch E, Ulbricht C, Kuo G, Szapary P, Smith M. Therapeutic applications of fenugreek . Alten Med Rev. 2003; 8: 20-27.
40. Handa T, Yamaguchi K, sono y, Yazawa K. Effects of fenugreek seed extract in obese mice fed a high-fat diet. Biosci Biotechnol Biochem. 2005;69:1186-1188.
41. Sharma RD, Raghuram TC, Rao NS. Effect of fenugreek seeds on blood glucose and serum lipids in type-1 diabetes. Eur J Clin Nutr. 1990;44:301-306.
42. Annida B, Stanely Mainzen, Prince P. Supplementation of fenugreek leaves lower lipid profile in streptozocin-induced diabetic rats. J Med Food. 2004;7:153-156.
43. Hannan JM, Rokeya B, Faruque O, Nahar N, Mosihuzzaman M, et al. Effect of soluble dietary fibre fraction of Trigonella foenum graecum on glycemic, insulinemic, lipidemic and platelet aggregation status of Type 2 diabetic model rats. J Ethnopharmacol. 2003;88:73-77.
44. Raju J, Bird RP. Alleviation of hepatic steatosis accompanied by modulation of plasma and liver TNF-alpha levels by Trigonella foenum-graecum(fenugreek) seeds in Zucker obese (fa/fa) rats. Int J Obese (Lond). 2006;30:1298-1307.
45. Gregoire FM. Adipocyte differentiation: from fibroblast to endocrine cell. Exp Biol Med. 2001; 226:997-1002.
46. Ntambi JM, Young-Cheul K. Adipocyte differentiation and gene expression. J Nutr. 2000;130:3122S-3126S.
47. Baquer NZ, Kumar P, Taha A, Kale RK, Cowsik SM, et al. Metabolic and molecular action of Trigonella foenum-graecum (fenugreek) and trace metals in experimental diabetic tissues. J Biosci. 36(2):383-396.
48. Annida B, Prince PS. Supplementation of fenugreek leaves reduces oxidative stress in streptozotocin-induced diabetic rats. J Med Food. 2005;8(3):382-385.