Mechanisms responsible for the vascular effect of aqueous Trigonella foenum-graecum leaf extract in diabetic rats

Recent Therapeutic Interventions of Fenugreek Seed: A Mechanistic Approach

Fenugreek seeds have widespread relations with Ayurveda, Unani, and Arabic medicine. The seeds were useful for the treatment and prevention of different ailments. Fenugreek (Trigonella foenum-graecum) or methi is from the Leguminosae family and are primarily known for its anti-diabetic and hypocholesterolemic activities. The germinated fenugreek seeds were used in the treatment of E.coli infection in Germany and France. The important phytoconstituents responsible for such medicinal applications are saponins, polyunsaturated fatty acids, galactomannans, trigonelline, and 4-hydroxy isoleucine. Flavonoids, apigenin 6,8-di-C-glucoside, apigenin-6-C-glucosyl-8-C-galactoside, 6-Cgalactosyl- 8-C-arabinoside are the chief ingredients of fenugreek seeds; responsible for reducing blood glucose while given to diabetic rats, whereas important flavones are epigenin, luteolin and vitexin. The other major bioactive components in fenugreek seeds are polyphenols like rhaponticin and isovitexin. Fenugreek seeds contain phosphorus and are categorized into different classes such as inorganic phosphorus, phospholipids, phytates, phosphor-proteins, and nucleic acid. Germinated seeds profusely filled with amino acids with amino acids, proteins, ascorbic acid, sugars. Further, this review shares information about the recent therapeutic intervention not covered earlier; on in vivo and in vitro and some clinical applications against certain interesting ailments other than older applications. This review includes certain nano delivery systems of Fenugreek seeds and their medicinal application.

Fenugreek (Trigonella Foenum-Graecum) Seed Flour and Diosgenin Preserve Endothelium-Dependent Arterial Relaxation in a Rat Model of Early-Stage Metabolic Syndrome

Fenugreek is a common herb possessing several bioactive components including diosgenin. Here, dietary fenugreek seed flour and diosgenin were evaluated on a model of endothelium-dependent vasorelaxation by abdominal aortas isolated from rats receiving high-fat, high-sugar diet (HFHSD). 60 male Wistar rats were randomized into six groups: (i) negative control getting conventional rat feed regimen; (ii) positive control receiving HFHSD; (iii) a test group fed 2 g/kg bw/day fenugreek seed flour (containing 10 mg/kg bw/day diosgenin) + HFHSD; (iv) three test groups fed 1, 10 and 50 mg/kg bw/day diosgenin + HFHSD. Alimentary treatments were carried out for six weeks. The abdominal aortas were isolated, and 2 mm wide rings were sectioned off and mounted at a resting tension of 10 mN in organ baths containing Krebs solution (36 °C) exposed to 95% O₂ and 5% CO₂. After 60-min incubation, a norepinephrine concentration-response (E/c) curve was generated to determine their half-maximal effective concentration (EC₅₀) value. After 60-min wash-out, a pre-contraction with norepinephrine EC₅₀ was made, followed by an acetylcholine E/c curve. Plasma glutathione levels, glutathione-handling enzyme activities and blood antioxidant capacities were also determined. HFHSD significantly decreased the dilatory response to acetylcholine and increased plasma glutathione levels and these effects were significantly reversed by fenugreek seed flour, 10 and 50 mg/kg bw/day diosgenin. Both fenugreek and diosgenin treatments prevent HFHSD-induced endothelial dysfunction and redox changes. As fenugreek treatment was more effective at lower acetylcholine concentrations than diosgenin treatments, components of fenugreek other than diosgenin may contribute to the beneficial effects of dietary fenugreek seed flour.

The vasorelaxant effect of simvastatin in isolated aorta from diabetic rats

BACKGROUND

The increasing incidence of diabetes mellitus (DM) is of great clinical significance. In this study, we aimed to investigate whether exposure of endothelium-intact aortic rings to simvastatin could have a vasorelaxant effect in diabetic rats.

METHODS

For induction of diabetes, streptozotocin (STZ) (60 mg/kg, i.p., single dose) was used. After 1 month, the cumulative reaction of isolated endothelium-intact aortic rings was determined to KCl and phenylephrine (PE) in the absence and presence of nitric oxide (NO) synthase inhibitor, i.e., nitro-L-arginine-methyl ester (L-NAME), and prostaglandin synthesis inhibitor, i.e., indomethacin. Meanwhile, the role of extracellular calcium was assessed in this respect.

RESULTS

At the end of the study, the addition of simvastatin (at a concentration ≥ 10-5 M) caused a significant concentration-dependent relaxation response of PE-precontracted aortic rings for both control and diabetic groups (at a significant difference of P < 0.050), and this difference did not exist for KCl-precontracted aortic rings. Furthermore, both L-NAME (100 µM) and indomethacin (10 µM) significantly diminished the vasorelaxant response following simvastatin addition. Meanwhile, there was no statistically significant difference between control and diabetic groups in the absence of extracellular calcium.

CONCLUSION

The results of this study suggest that simvastatin is able to relax PE-precontracted aortic rings isolated from STZ-diabetic rats via modulation of NO- and prostaglandin-dependent signaling and its effect is not via modulation of calcium mobilization from intracellular stores.

Pharmacological effects of Trigonella foenum-graecum L. in health and disease

CONTEXT

The health benefits and medicinal properties of herbal food products are known since antiquity. Fenugreek [Trigonella foenum-graecum Linn. (Fabaceae)], a seed spice used to enhance flavor, color and texture of food, is employed for medicinal purposes in many traditional systems. A number of epidemiological studies and laboratory research have unraveled the biological actions of fenugreek.

OBJECTIVE

Research on fenugreek in recent years has identified a number of health benefits and physiological attributes in both experimental animals as well as clinical trials in humans. In this study we have reviewed the available scientific literature on fenugreek.

METHODS

This review article summarizes and reviews published experimental studies and scientific literature from the databases including PubMed, Google and local library searches.

RESULTS

The information available in the literature on the health benefits and pharmaceutical effects of Trigonella accounts for its known medicinal properties and adds new therapeutic effects in newer indications. Besides its known medicinal properties such as carminative, gastric stimulant, antidiabetic and galactogogue (lactation-inducer) effects, newer research has identified hypocholesterolemic, antilipidemia, antioxidant, hepatoprotective, anti-inflammatory, antibacterial, antifungal, antiulcer, antilithigenic, anticarcinogenic and other miscellaneous medicinal effects of fenugreek. Although most of these studies have used whole seed powder or different forms of extracts, some have identified active constituents from seeds and attributed them medicinal values for different indications.

CONCLUSION

The resarch on Trigonella exhibits its health benefits and potential medicinal properties in various indications and has little or no side effects, suggesting its pharmaceutical, therapeutic and nutritional potential.