Effect of fenugreek seeds on blood lipid peroxidation and antioxidants in diabetic rats

Environmental cadmium exposure during pregnancy causes diabetes-like phenotypes in mouse offspring: Association with oxidative stress in the fetal liver

Cadmium (Cd), a noxious heavy metal, is widespread in the living environment. Gestational exposure to Cd at environmental dose has been shown to cause fetal growth restriction (FGR). However, the long-term effects and the mechanisms underlying environmental Cd exposure on glucose metabolism in offspring remain unclear. Here, we established a murine model to study the impacts of gestational exposure to environmental Cd on glucose metabolism at different life stages of offspring. Results demonstrated that the offspring mice developed hyperglycemia in puberty and impaired glucose tolerance in adulthood following maternal Cd exposure during gestation. Further mechanistic investigation showed that Cd exposure upregulated the expression of key proteins in hepatic gluconeogenesis, including p-CREB, PGC-1α and G6PC, in pubertal and adult offspring. In addition, we demonstrated that Cd exposure during pregnancy markedly elevated the level of oxidative stress-related proteins, including NOX2, NOX4 and HO-1, in the fetal liver. The effects of gestational exposure to N-acetylcysteine (NAC), a free-radical scavenging antioxidant, presented that NAC supplementation alleviated hepatic oxidative stress in fetuses, and thereby reversed hyperglycemia and glucose intolerance in mouse offspring. Collectively, our data suggested that gestational exposure to environmental Cd caused diabetes-like phenotypes via enhancing hepatic gluconeogenesis, which is associated with oxidative stress in fetal livers. This work provides new insights into the protective effects of antioxidants on fetal-originated diabetes triggered by environmental toxicants.

Trigonella foenum-graecum seeds extract plays a beneficial role on brain antioxidant and oxidative status in alloxan-induced Wistar rats

Context

Trigonella foenum-graecum (TriFG) exhibits increased scavenger enzymatic activities and reduces the production of reactive oxygen species in diabetic rats.

Objective

The present study was aimed to investigate the effect of TriFG on lipid peroxidation levels and antioxidant status in brain tissue of rats exposed to alloxan.

Materials and Methods

Healthy male rats (180 ± 10 g) were allocated into five groups. Animals in group 1 maintained on normal tap water served as controls and rats in groups 2, 3, 4, and 5 were treated as experimental groups. Rats in group 2 were intraperitoneally injected with alloxan (120 mg/kg BW) and treated as diabetic rats, whereas rats in groups 3 and 4 were maintained on same experimental regimen as that of rats in groups 1 and 2, respectively, and in addition, they were orally gavaged with herbal extracts of TriFG (0.25 g/kg BW). Diabetic rats treated with glibenclamide in group 5 were used as positive controls.

Results and Discussion

Significant (P < 0.001) increase in the antioxidant enzymes with a significant (P < 0.001) decrease in the lipid peroxidation levels were observed in the brain tissue of diabetic rats treated with TriFG extract as compared to diabetic and glibenclamide-treated rats. No significant changes were observed in pro- and antioxidant levels in brain tissue of rats treated with TriFG extract alone when compared to normal rats. In diabetic rats, brain mitochondrial and cytosolic enzymes like succinate dehydrogenase, glutamate dehydrogenase, and glucose-6-phosphate dehydrogenase activity levels were significantly (P < 0.05) decreased with reversely increased was observed in lactate dehydrogenase activity (P < 0.05).

Conclusions

The findings of the present study suggested that TriFG, through its antioxidant properties, protects brain tissue by mitigating oxidative stress induced by alloxan-exposed rats. TriFG extract significantly increased the antioxidant and oxidative properties in diabetic rats when compared with the control group rats.

Cardiotoxicity and myocardial infarction-associated DNA damage induced by thiamethoxam in vitro and in vivo: Protective role of Trigonella foenum-graecum seed-derived polysaccharide

The risk of pesticides on the human health and environment has drawn increasing attention. Today, new tools are developed to reduce pesticide adverse effects. This study aimed to evaluate the toxicity induced by, thiamethoxam (TMX), and the cytoprotective effect of a novel polysaccharide, named fenugreek seed water polysaccharide (FWEP) in vitro using H9c2 cardiomyoblastes and in vivo using Wistar rat model. Animals were assigned into four groups per eight rats each: group 1 served as a control group, group 2 received TMX, group 3, and group 4 received both FWEP and TMX tested at two doses (100 and 200 mg/kg, respectively). Regarding the in vitro study, our results demonstrated that TMX induced a decrease in H9c2 cell viability up to 70% with the highest concentration. In vivo, TMX injection induced marked heart damage noted by a significant increase in plasma lactate dehydrogenase, creatine phosphokinase, troponin-T, aspartate amino transferase activities, cholesterol, and triglyceride levels. Concomitant alterations in cardiac antioxidant defense system revealed depletion in the levels of glutathione and non-protein thiol and an increase in the activity of superoxide dismutase, catalase, and glutathione peroxidase. Similarly, a significant increase in heart lipid, malondialdehyde, advanced oxidation protein product and in protein carbonyls levels was also noted. In addition, heart tissues histo-architecture displayed major presence of apoptosis and necrosis as confirmed by DNA degradation. However, supplementation with FWEP alleviated heart oxidative damage and genotoxicity. In this manner, ABTS radical-scavenging activity, linoleic acid oxidation tests and heart genomic and DNA nicking assay had proved FWEP strong antioxidant potential. In conclusion, FWEP provided significant protection against TMX-induced heart injury, and could be a useful and efficient agent against cardiotoxicity and atherosclerosis.

Alleviation of Cardiac Damage by Dietary Fenugreek (Trigonella foenum-graecum) Seeds is Potentiated by Onion (Allium cepa) in Experimental Diabetic Rats via Blocking Renin-Angiotensin System

Hyperglycemia is one of the metabolic and homeostatic abnormalities that increase the cardiovascular mortality in diabetic patients by increased oxidative stress. We have recently reported amelioration of oxidative stress in cardiac tissue by dietary fenugreek (Trigonella foenum-graecum) seeds and onion (Allium cepa) in streptozotocin-induced diabetic rats. The mechanistic aspects of the cardio-protective influence of dietary fenugreek seeds (10%) and onion (3% powder) both individually and in combination on hyperglycemia-mediated cardiac damage was further investigated in this study on streptozotocin-induced diabetic rats. Cardio-protective influence of these dietary spices was evidenced by their blocking potential on renin-angiotensin system. This might be the consequence of reduced activation of angiotensin-converting enzyme (ACE) and angiotensin type 1 receptor (AT₁) in cardiac tissue. The combination produced an additive effect on ACE and AT₁ protein and mRNA expressions. Increased expression of type IV collagen, fibronectin, Bax, 4-hydroxynonenal, iNOS and metabolites of nitric oxide (nitrate/nitrite) along with disturbed PUFA-to-SFA ratio and activities of cardiac marker enzymes in blood confirmed the myocardial damage. Dietary fenugreek seed, onion and fenugreek + onion were found to ameliorate these pathological changes in the cardiovascular system. The beneficial effect being higher with the combination sometime amounting to additive (iNOS expression) or even a synergistic (cardiac Bax and type IV collagen expression and circulatory marker enzymes) in diabetic rats. Thus, the results of present investigation suggested that the combination of fenugreek seeds and onion offers higher beneficial influence in ameliorating cardiac damage accompanying diabetes.

Medicinal Plants with Multiple Effects on Diabetes Mellitus and Its Complications: a Systematic Review

PURPOSE OF REVIEW

This systematic review describes evidence concerning medicinal plants that, in addition to exerting hypoglycemic effects, decrease accompanying complications such as nephropathy, neuropathy, retinopathy, hypertension, and/or hyperlipidemia among individuals with diabetes mellitus (DM).

RECENT FINDINGS

Studies on the antidiabetic mechanisms of medicinal plants have shown that most of them produce hypoglycemic activity by stimulating insulin secretion, augmenting peroxisome proliferator-activated receptors (PPARs), inhibiting α-amylase or α-glucosidase, glucagon-like peptide-1 (GLP-1) secretion, advanced glycation end product (AGE) formation, free radical scavenging plus antioxidant activity (against reactive oxygen or nitrogen species (ROS/RNS)), up-regulating or elevating translocation of glucose transporter type 4 (GLUT-4), and preventing development of insulin resistance. Not only are medicinal plants effective in DM, but many of them also possess a variety of effects on other disease states, including the complications of DM. Such plants may be appropriate alternatives or adjuncts to available antidiabetic medications.

Comparative whole genome transcriptome analysis and fenugreek leaf extract modulation on cadmium‑induced toxicity in liver cells

Cadmium (Cd), an economically valuable metal, is widely used in various industrial processes. Although it is of economic value, it is hazardous to human health. Cd accumulates in vital organs where it causes various diseases. Natural compounds with chelating or antioxidant properties have been tested to reduce the toxic effect of Cd. The anti‑oxidant, anti‑diabetic and hypocholesterolemic properties of fenugreek (Trigonella foenum-graecum) leaves make it a candidate for investigation as protective agent against Cd‑induced toxicity. In the present study, the protective effects of fenugreek leaf extract (FLE) on cell viability, morphology, and whole genomic transcription in cadmium chloride (CdCl2)‑treated rat liver cells were analyzed. The cells were treated with 25 µM CdCl2 alone, or co‑treated with 5 µg/ml FLE for 48 h. The co‑treated cells were pretreated with FLE for 2 or 4 h, followed by CdCl2 treatment. Genomic transcription analysis was performed in the CdCl2‑treated cells following treatment for 6 h. The CdCl2 caused a significant decrease in viability (35.8±4.1%) and morphological distortion of the cells, compared with the untreated control cells; whereas 4 h pretreatment with FLE (5 µg/ml) reversed the Cd‑induced morphology alteration and increased the cell viability to 102±3.8%. Genomic transcription analysis of the CdCl2 only‑treated cells showed 61 upregulated and 124 downregulated genes, compared with 180 upregulated and 162 downregulated genes in the FLE pretreated cells. Furthermore, 37 and 26% of the affected total genomic genes in the CdCl2 only‑treated cells were involved in binding and catalytic activities, respectively, whereas 50 and 20% of the genes in the FLE pretreated cells were involved in binding and catalytic activities, respectively. In conclusion, these results suggested that genome transcriptome modulation may be important in the protective effect of FLE against Cd‑induced toxicity in normal rat liver cells.

Phytotherapy in the Management of Diabetes: A Review

Phytotherapy has long been a source of medicinal products and over the years there have been many attempts to use herbal medicines for the treatment of diabetes. Several medicinal plants and their preparations have been demonstrated to act at key points of glucidic metabolism. The most common mechanisms of action found include the inhibition of α-glucosidase and of AGE formation, the increase of GLUT-4 and PPARs expression and antioxidant activity. Despite the large amount of literature available, the actual clinical effectiveness of medicinal plants in controlling diabetes-related symptoms remains controversial and there is a crucial need for stronger evidence-based data. In this review, an overview of the medicinal plants, which use in the management of diabetes is supported by authoritative monographs, is provided. References to some species which are currently under increasing clinical investigation are also reported.

Haemato-protective influence of dietary fenugreek (Trigonella foenum-graecum L.) seeds is potentiated by onion (Allium cepa L.) in streptozotocin-induced diabetic rats

We have recently reported the beneficial modulation of metabolic abnormalities and oxidative stress in diabetic rats by dietary fenugreek seeds and onion. This investigation evaluated the protective influence of dietary fenugreek seeds (100 g kg^-1) and onion (30 g kg^-1) on erythrocytes of streptozotocin-induced diabetic rats, through modulation of reduced haematological indices and antisickling potency. This study also evaluated the altered erythrocyte membrane lipid profile and beneficial countering of increased lipid peroxidation, osmotic fragility, along with reduced membrane fluidity and deformability, nitric oxide production and echinocyte formation. Dietary fenugreek seeds and onion appeared to counter the deformity and fragility of erythrocytes partially in diabetic rats by their antioxidant potential and hypocholesterolemic property. The antisickling potency of these spices was accomplished by a substantial decrease in echinocyte population and AGEs in diabetic rats. Further insight into the factors that might have reduced the fluidity of erythrocytes in diabetic rats revealed changes in the cholesterol: phospholipid ratio, fatty acid profile, and activities of membrane-bound enzymes. Dietary fenugreek seeds and onion offered a beneficial protective effect to the red blood cells, the effect being higher with fenugreek + onion. This is the first report on the hemato-protective influence of a nutraceutical food component in diabetic situation.

Amelioration of oxidative stress by dietary fenugreek (Trigonella foenum-graecum L.) seeds is potentiated by onion (Allium cepa L.) in streptozotocin-induced diabetic rats

Oxidative stress has a crucial role in the progression of diabetes and its complications. Soluble fibre-rich fenugreek seeds (Trigonella foenum-graecum L.) are understood to have a beneficial effect in the management of diabetes. Previously, we have shown that the amelioration of diabetic hyperglycemia and related metabolic abnormalities was potentiated by onion (Allium cepa L.) in experimental rats. The present study evaluated the additive beneficial effect of dietary fenugreek seeds (10%) and onion (3%) on oxidative stress in diabetic rats. These dietary interventions lowered oxidative stress, the combination producing a higher beneficial effect (p < 0.05), although not additive. Dietary fenugreek, onion, or fenugreek+onion countered hypercholesterolemia (p < 0.05), especially from low-density lipoprotein−associated fraction by 43%, 35%, and 54%, respectively. Elevated concentrations of cholesterol and triglycerides in the liver and heart under diabetic conditions were significantly counteracted by these dietary interventions, with the additive combination resulting in greater effect. These findings were also corroborated by restoration of histopathological abnormalities of heart and liver tissues along with lowered heart and liver weights. It is inferred that an alleviation of oxidative stress contributes further to the antidiabetic influence and this nutraceutical potential of fenugreek seeds and onion was higher when consumed together.

Diosgenin and 5-Methoxypsoralen Ameliorate Insulin Resistance through ER-α/PI3K/Akt-Signaling Pathways in HepG2 Cells

To determine the effects and the underlying mechanism of diosgenin (DSG) and 5-methoxypsoralen (5-MOP), two main active components in the classical Chinese prescription Hu-Lu-Ba-Wan (HLBW), on insulin resistance, HepG2 cells were incubated in medium containing insulin. Treatments with DSG, 5-MOP, and their combination were performed, respectively. The result showed that the incubation of HepG2 cells with high concentration insulin markedly decreased glucose consumption and glycogen synthesis. However, treatment with DSG, 5-MOP, or their combination significantly reversed the condition and increased the phosphorylated expression of estrogen receptor-α (ERα), sarcoma (Src), Akt/protein kinase B, glycogen synthase kinase-3β (GSK-3β), and the p85 regulatory subunit of phosphatidylinositol 3-kinase p85 (PI3Kp85). At the transcriptional level, expression of the genes mentioned above also increased except for the negative regulation of GSK-3β mRNA. The increased expression of glucose transport-4 (GLUT-4) was meanwhile observed through immunofluorescence. Nevertheless, the synergistic effect of DSG and 5-MOP on improving glycometabolism was not obvious in the present study. These results suggested that DSG and 5-MOP may improve insulin resistance through an ER-mediated PI3K/Akt activation pathway which may be a new strategy for type 2 diabetes mellitus, especially for women in an estrogen-deficient condition.

Nutrigenomics and its Impact on Life Style Associated Metabolic Diseases

Post-human genome revelation observes the emergence of 'Nutigenomics' as one of the exciting scientific advancement influencing mankind around the world. Food or more precisely 'nutrition' has the major impact in defining the cause-response interaction between nutrient (diet) and human health. In addition to substantial understanding of nutrition-human-health interaction, bases of 'nutrigenomic' development foster on advent in transcriptomics, genomics, proteomics and metabolomics as well as insight into food as health supplement. Interaction of selected nutrient with associated genes in specific organ or tissue necessary to comprehend that how individual's genetic makeup (DNA transcribed into mRNA and then to proteins) respond to particular nutrient. It provided new opportunities to incorporate natural bioactive compounds into food for specific group of people with similar genotype. As inception of diabetes associated with change in gene expression of, not limited to, protein kinase B, insulin receptor, duodenal homeobox and glucokinase, thus, targeting such proteins by modifying or improving the nutritional availability or uptake may help to devise novel food, supplements, or nutraceuticals. In this article, various aspects of R&D in nutrigenomics are reviewed to ascertain its impact on human health, especially with life-style associated diseases.

Trigonella foenum-graecum Seed Extract, 4-Hydroxyisoleucine, and Metformin Stimulate Proximal Insulin Signaling and Increase Expression of Glycogenic Enzymes and GLUT2 in HepG2 Cells

BACKGROUND

Fenugreek (Trigonella foenum-graecum) is globally recognized for its medicinal properties and hypoglycemic effects. The seed extract as well as its active compound, 4-hydroxyisoleucine (4-OH-Ile), have been shown to reduce hyperglycemic insulin resistance. The mechanism by which this occurs has not been investigated in human liver cells (HepG2) in comparison to the antihyperglycemic drug, metformin.

METHODS

We investigated the effects of an aqueous fenugreek seed extract (FSE), 4-OH-Ile, and metformin in HepG2 cells relative to insulin as a positive control. Cells were treated with FSE and 4-OH-Ile at 100 ng/mL under normoglycemic (5 mM glucose) and hyperglycemic (30 mM glucose) conditions for 72 hr. Tyrosine phosphorylation of insulin receptor-β (IR-β), protein kinase B (Akt), glycogen synthase kinase-3α/β (GSK-3α/β), and glucose transporter 2 (GLUT2) was determined by western blotting. Gene expression of sterol regulatory element-binding protein 1c (SREBP1c), GLUT2, glycogen synthase (GS), and glucokinase (GK) was evaluated by quantitative polymerase chain reaction, and supernatant glucose levels were measured using the Piccolo biochemistry analyzer.

RESULTS

Under normo- and hyperglycemic conditions, FSE, 4-OH-Ile, insulin (100 ng/mL), and metformin (2 mM) caused a significant increase in phosphorylation of IR-β, Akt, GSK-3α/β, and GLUT2. Glucose uptake, however, was most significantly increased in FSE-treated cells during both conditions. FSE induced the most significant changes in downstream insulin signaling, GS, GK, SREBP1c, and GLUT2 expression compared to 4-OH-Ile, metformin, and insulin. In addition, FSE significantly increased glucose uptake.

CONCLUSIONS

Collectively, these findings provide a mechanism by which FSE exerts antihyperglycemic effects similar to metformin and insulin that occurs via enhanced insulin signaling, gene expression, and increasing glucose uptake.

Roller milling process for fractionation of fenugreek seeds (Trigonella foenumgraecum) and characterization of milled fractions

The fenugreek seed is the richest source of soluble and insoluble fiber and also known for its medicinal and functional properties. The major objective of this present study is fractionation of the fenugreek by roller milling method and characterization of roller milled fractions. The effects of moisture conditioning on fenugreek roller milling were studied using standard methods. The results observed were increase in coarse husk from 33.75-42.46 % and decrease in flour yield from 49.52-41.62 % with increase in addition of moisture from 12-20 %. At 16 % conditioning moisture, the yield of coarse husk was 40.87 % with dietary fiber and protein content of 73.4 % and 6.96 % respectively. The yellowness value (b) for the coarse husk (29.68) found to be lowest at 16 % conditioning moisture compared to the other coarse husk samples, showing maximum clean separation. The fiber fractions showed the viscosity of 6,392 cps at 2 % w/v concentration. The flour fraction was higher in protein (41.83 %) and fat (13.22 %) content. Roller milling process of fenugreek was able to produce > 40 % of coarse husk with 73.4 % dietary fiber (25.56 % soluble & 47.84 % insoluble) and > 48 % flour with 41.83 % protein content, where as the whole fenugreek contained 22.5 % protein & 51.25 % dietary fiber. Thus roller milling has proved to be a valuable method for the fractionation of fenugreek to obtain fiber and protein rich fractions.

Effects of Trigonella foenum-graecum (L.) on retinal oxidative stress, and proinflammatory and angiogenic molecular biomarkers in streptozotocin-induced diabetic rats

The aim of the present study was to investigate the protective effects of Trigonella foenum-graecum Linn. (fenugreek) in Streptozotocin-induced diabetic rat retina. Fenugreek (100 and 200 mg/kg body weights) treatment was carried out for 24 weeks and evaluated for inflammatory [tumor necrosis factor (TNF)-α and interleukin (IL)-1β] and angiogenic [vascular endothelial growth factor (VEGF) and protein kinase C (PKC)-β] molecular biomarkers. Retinal oxidative stress was evaluated by estimating antioxidant (Glutathione, Superoxide dismutase, and Catalase) parameters. Fluorescein angiography was performed to detect retinal vascular leakage. Electron microscopy was performed to determine basement membrane thickness. In the present study, significant rises in the expressions of retinal inflammatory (TNF-α and IL-1β) and angiogenic (VEGF and PKC-β) molecular biomarkers were observed in diabetic retinae compared with normal retinae. However, fenugreek-treated retinae showed marked inhibition in the expression of inflammatory and angiogenic molecular biomarkers. Moreover, results from the present study showed positive modulatory effects of fenugreek on retinal oxidative stress. Fluorescein angiograms and fundus photographs obtained from diabetic retinae showed retinal vascular leakage. On the other hand, fenugreek-treated retinae did not show vascular leakage. Further, thickened BM was recorded in diabetic retina compared with normal retinae. However, fenugreek-treated retinae showed relatively lesser thickening of capillary BM. In conclusion, it may be postulated that fenugreek has great potential in preventing diabetes-induced retinal degeneration in humans after regular consumption in the specified dosage.

Protective effect of Trigonella foenum-graecum on thioacetamide induced hepatotoxicity in rats

Trigonella foenum-graecum belongs to the family Fabaceae and is indigenous to countries that lie on the eastern shores of the Mediterranean Sea and is also cultivated in India, Egypt and Africa. This study provides the evidence indicating the therapeutic effect of the extract prepared from the dried seeds of Trigonella foenum-graecum on an animal model of hepatotoxicity and on cell proliferation. Rats were induced liver cirrhosis by thioacetamide (0.03% in water for 16 weeks). Transmission electron microscopy of the liver tissue was done to evaluate liver cirrhosis. The herbal extract was administered orally for 3 weeks after induction and biochemical estimations were done. After the administration of extract the oxidative stress and lipid peroxidation were reversed. The elevated levels of alkaline phosphatase, γ-glutamyl transferase and selected biochemical markers of liver cirrhosis including drug metabolizing enzymes were also reversed. The study has implications in finding a treatment for liver cirrhosis by a natural herbal drug with no side effects.

Comparative study on hypocholesterolemic and antioxidant activities of various extracts of fenugreek seeds

The hypocholesterolemic and antioxidant activities of various extracts (water, methanol, ethyl acetate, hexane, dichloro-methane) of fenugreek seeds were investigated in cholesterol-fed rats. Only the ethyl acetate extract reduced total cholesterol, triglycerides, and low-density lipoprotein cholesterol (LDL-C) and increased high-density lipoprotein cholesterol (HDL-C) compared with those of rats fed a cholesterol-rich diet (HCD). Furthermore, the content of thiobarbituric acid-reactive substances (TBARS), and catalase and superoxide dismutase (SOD) in liver, heart and kidney decreased significantly after oral administration of the ethyl acetate extract, compared with those of HCD-fed rats. The phenolic and flavonoïd contents were highest in the methanol and the ethyl acetate extracts. These results showed that the ethyl acetate extract of the fenugreek seeds had a significant hypocholesterolemic effect and antioxidant activity in cholesterol-fed rats, whether this is partly due to the presence of flavonoïds in the extract needs further study.

Preventive and curative effect of Trigonella foenum-graecum L. seeds in C57BL/6J models of type 2 diabetes induced by high-fat diet

ETHNOPHARMACOLOGICAL RELEVANCE

Trigonella foenum-graecum L. (TFG) is traditionally used to treat diabetes in North Africa. we therefore tested the effects of the hydro-alcoholic extract of TFG seeds in a C57/BL6J mouse model of diabetes induced by a standardised high-fat diet (HFD).

MATERIALS AND METHODS

Plant extracts (2 g/kg daily) were administered orally by gavage at the start of HFD, or after confirmation of established diabetes (17th week), for 20 or 18 weeks, respectively, to male C57BL/6J mice. Animals were weighed; food intake and plasma glucose, lipid profile, insulin and insulin resistance were measured.

RESULTS

TFG extracts opposed the development of diabetes: compared with untreated HFD mice, TFG-treated HFD mice had lower mean (± SD) plasma glucose (129.3 ± 39.4 vs. 183.1 ± 19.1mg/dL, p<0.05), plasma insulin (1.3 ± 0.8 vs. 3.1 ± 1.8 ng/mL, p<0.05) and triglycerides (18.9 ± 12.9 vs. 48.9 ± 12.1mg/dL, p<0.05), and less insulin resistance as estimated by the homeostasis model assessment (HOMA: 9.7 ± 11.1 vs. 38.3 ± 26.6, p<0.05). In mice with established diabetes, TFG reduced fasting plasma glucose (170.4 ± 24.1 vs. 229.0 ± 20.8 mg/dL, p<0.05), plasma insulin (1.7 ± 1.3 vs. 3.3 ± 14.3 ng/mL, p<0.05) and insulin resistance (HOMA: TFG: 19.2 ± 15.7 vs. HFD control: 38.5 ± 30.3, p<0.05). In addition, administration of TFG extract also caused significant reduction in triglycerides (17.9 ± 9.7 vs. 62.8 ± 18.3 mg/dL, p<0.05) and total cholesterol (1.30 ± 0.20 vs. 1.80 ± 1.10 g/L, p<0.05), and an increase in HDL-cholesterol (1.6 ± 0.2 vs. 1.2 ± 0.1 g/L). The plant extract had no effect on calorie intake or body weight.

CONCLUSION

TFG extract opposed the development of experimental HFD diabetes in mice, and had an anti-diabetic effect in mice with established diabetes.

Diosgenin promotes oligodendrocyte progenitor cell differentiation through estrogen receptor-mediated ERK1/2 activation to accelerate remyelination

Differentiation of oligodendrocyte progenitor cells (OPCs) into mature oligodendrocytes is a prerequisite for remyelination after demyelination, and impairment of this process is suggested to be a major reason for remyelination failure. Diosgenin, a plant-derived steroid, has been implicated for therapeutic use in many diseases, but little is known about its effect on the central nervous system. In this study, using a purified rat OPC culture model, we show that diosgenin significantly and specifically promotes OPC differentiation without affecting the viability, proliferation, or migration of OPC. Interestingly, the effect of diosgenin can be blocked by estrogen receptor (ER) antagonist ICI 182780 but not by glucocorticoid and progesterone receptor antagonist RU38486, nor by mineralocorticoid receptor antagonist spirolactone. Moreover, it is revealed that both ER-alpha and ER-beta are expressed in OPC, and diosgenin can activate the extracellular signal-regulated kinase 1/2 (ERK1/2) in OPC via ER. The pro-differentiation effect of diosgenin can also be obstructed by the ERK inhibitor PD98059. Furthermore, in the cuprizone-induced demyelination model, it is demonstrated that diosgenin administration significantly accelerates/enhances remyelination as detected by Luxol fast blue stain, MBP immunohistochemistry and real time RT-PCR. Diosgenin also increases the number of mature oligodendrocytes in the corpus callosum while it does not affect the number of OPCs. Taking together, our results suggest that diosgenin promotes the differentiation of OPC into mature oligodendrocyte through an ER-mediated ERK1/2 activation pathway to accelerate remyelination, which implicates a novel therapeutic usage of this steroidal natural product in demyelinating diseases such as multiple sclerosis (MS).

A pharmacological appraisal of medicinal plants with antidiabetic potential

Diabetes mellitus is a complicated metabolic disorder that has gravely troubled the human health and quality of life. Conventional agents are being used to control diabetes along with lifestyle management. However, they are not entirely effective and no one has ever been reported to have fully recovered from diabetes. Numerous medicinal plants have been used for the management of diabetes mellitus in various traditional systems of medicine worldwide as they are a great source of biological constituents and many of them are known to be effective against diabetes. Medicinal plants with antihyperglycemic activities are being more desired, owing to lesser side-effects and low cost. This review focuses on the various plants that have been reported to be effective in diabetes. A record of various medicinal plants with their established antidiabetic and other health benefits has been reported. These include Allium sativa, Eugenia jambolana, Panax ginseng, Gymnema sylvestre, Momrodica charantia, Ocimum sanctum, Phyllanthus amarus, Pterocarpus marsupium, Trigonella foenum graecum and Tinospora cordifolia. All of them have shown a certain degree of antidiabetic activity by different mechanisms of action.

Dietary fenugreek and onion attenuate cholesterol gallstone formation in lithogenic diet-fed mice

An animal study was conducted to evaluate the antilithogenic effect of a combination of dietary fenugreek seeds and onion. Lithogenic conditions were induced in mice by feeding them a high (0.5%) cholesterol diet (HCD) for 10 weeks. Fenugreek (12%) and onion (2%) were included individually and in combination in this HCD. Fenugreek, onion and their combination reduced the incidence of cholesterol gallstones by 75%, 27% and 76%, respectively, with attendant reduction in total cholesterol content by 38-42%, 50-72% and 61-80% in serum, liver and bile respectively. Consequently, the cholesterol/phospholipid ratio was reduced significantly in serum, liver and bile. The cholesterol saturation index of bile was reduced from 4.14 to 1.38 by the combination of fenugreek and onion and to 2.33 by onion alone. The phospholipid and bile acid contents of the bile were also increased. Changes in the hepatic enzyme activities (3-hydroxy-3-methylglutaryl Coenzyme A reductase, cholesterol-7α-hydroxylase and cholesterol-27-hydroxylase) induced by HCD were countered by fenugreek, onion and their combination. Hepatic lipid peroxides were reduced by 19-22% and 39-45% with fenugreek, onion and their combination included in the diet along with the HCD. Increased accumulation of fat in the liver and inflammation of the gallbladder membrane produced by HCD were reduced by fenugreek, onion and their combination. The antilithogenic influence was highest with fenugreek alone, and the presence of onion along with it did not further increase this effect. There was also no additive effect of the two spices in the recovery of antioxidant molecules or in the antioxidant enzyme activities.

Indian herbs and herbal drugs used for the treatment of diabetes

Traditional Medicines derived from medicinal plants are used by about 60% of the world’s population. This review focuses on Indian Herbal drugs and plants used in the treatment of diabetes, especially in India. Diabetes is an important human ailment afflicting many from various walks of life in different countries. In India it is proving to be a major health problem, especially in the urban areas. Though there are various approaches to reduce the ill effects of diabetes and its secondary complications, herbal formulations are preferred due to lesser side effects and low cost. A list of medicinal plants with proven antidiabetic and related beneficial effects and of herbal drugs used in treatment of diabetes is compiled. These include, Allium sativum, Eugenia jambolana, Momordica charantia Ocimum sanctum, Phyllanthus amarus, Pterocarpus marsupium, Tinospora cordifolia, Trigonella foenum graecum and Withania somnifera. One of the etiologic factors implicated in the development of diabetes and its complications is the damage induced by free radicals and hence an antidiabetic compound with antioxidant properties would be more beneficial. Therefore information on antioxidant effects of these medicinal plants is also included.

Molecular spectroscopic study of acid treated fenugreek seeds

Fenugreek seeds were subjected to acid treatment in order to activate its surface. XRF indicated that there was no change in the level of metals and metal oxides as a result of the treatment. FTIR of the treated fenugreek showed no change in the characteristic bands and/or structure of the fenugreek. A shift in both OH and metal oxide bands suggest a role for metal, hydrated metal and metal oxide in fenugreek seed. Molecular modeling suggests that metal oxides such as Al16O24 offer its surface for the adsorption of gases. The interaction of gases with metal oxide is depending on the type of gas rather than the type of coordination. Finally results indicate that fenugreek could be used safely to control the level of gases in stomach.

Acetylcholinesterase enzyme inhibitory potential of standardized extract of Trigonella foenum graecum L and its constituents

Ethno pharmacological approach has provided several leads to identify potential new drugs from plant sources, including those for memory disorders. Acetylcholinesterase inhibitors (AChEI) give a symptomatic relief to some of the clinical manifestations of the disease. The main objective of this study is to standardize the extract of Trigonella foenum graecum L with trigonelline by HPTLC method and determine the in vitro AChE inhibitory activity of Trigonella foenum graecum L and its constituents using galanthamine as a reference. Different concentrations of hydro alcoholic extract of Trigonella foenum graecum and trigonelline were subjected to HPTLC analysis using the mobile phase n propanol, methanol and water (4:1:2, v/v). The R(f) of trigonelline was found to be 0.43, and the correlation coefficient of 0.99 was indicative of good linear dependence of peak area on concentration. The concentration of trigonelline was found to be 13mgg(-1)w/w in the hydro alcoholic extract of Trigonella foenum graecum. The AChE inhibitory activity of crude fenugreek seed extracts, fractions and trigonelline was evaluated using Ellman's method in 96-well micro plate's assay and TLC bioassay detection. The ethyl acetate fraction of the alcohol extract (IC50 53.00 +/- 17.33microg/ml), and total alkaloid fraction (IC50 9.23+/-6.08microg/ml) showed potential AChE inhibition. Trigonelline showed IC50 233+/-0.12microM. Galanthamine was used as standard and it showed inhibition of acetyl cholinesterase with an IC50 value of 1.27+/-0.21microM.

Lipid-lowering and antioxidant effects of an ethyl acetate extract of fenugreek seeds in high-cholesterol-fed rats

The purpose of this study was to investigate the relationship between the lipid effects, the phenolic content, and the antioxidative effects of an ethyl acetate extract of fenugreek. Wistar rats fed a standard laboratory diet or cholesterol-rich diets for 16 weeks were used. The plasma lipid levels, total phenolics, and total flavonoid contents were measured, and the thiobarbituric acid reactive substances (TBARS) and antioxidant activities were examined. Administration of fenugreek ethyl acetate extract significantly lowered the plasma levels of total cholesterol (TC), triglycerides (TG), and low-density lipoprotein cholesterol (LDL-C), while increasing the plasma level of high-density lipoprotein cholesterol (HDL-C). Furthermore, the content of TBARS and catalase (CAT) and superoxide dismutase (SOD) activities in liver, heart and kidney decreased significantly after oral administration of the extract compared with those of rats fed a cholesterol-rich diet. These lipid effects and in vivo antioxidative effects were correlated with the in vitro phenolic content scavenging ability. In addition, three flavonoids (kaempferol 3-O-glycoside, apigenin-7-O-rutinoside, and naringenin) were identified by using an LC-MS/MS apparatus. Naringenin was the abundant flavonoid compound in the ethyl acetate extract, and its concentration reaches 7.23 +/- 0.09 mg/g of dry extract. These results revealed significant hypocholesterolemic effects and antioxidant activity in an ethyl acetate extract of fenugreek seed, which may be partly due to the presence of flavonoids, especially naringenin.

Aqueous extract of Trigonella foenum graecum (fenugreek) prevents cypermethrin-induced hepatotoxicity and nephrotoxicity

Cypermethrin (CM) is an important type II pyrethroid pesticide used extensively in pest control and is reported to cause hepatic and renal toxicity. Oxidative stress and lipid peroxidation (LPO) has been implicated in the toxicology of pyrethroids. Fenugreek is known for its antitoxic and antioxidant potential. We have investigated the protective effect of aqueous extract of germinated fenugreek seeds in CM-induced hepatic and renal toxicity. Male Wistar rats were treated with 1/10 LD(50) (25 mg/kg body weight) of CM and 10% aqueous extract of fenugreek (GFaq) for 60 days. CM treatment caused increased thiobarbituric acid reactive substances (TBARS), depletion in glutathione (GSH) and reduction in the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione-S-transferase (GST) in liver and kidneys. There was a significant reduction in total phospholipids and increased activities of phospholipases A (PLA) and C (PLC) in liver and kidneys and increased activities of serum marker enzymes, aspartate transaminase (AST), alanine tansaminase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and gamma glutamyl transferase (GGT). Treatment with 10% GFaq showed replenishment of antioxidant status and brought all the values to near normal, indicating the protective effect of fenugreek. Phytochemicals present in fenugreek could play an important role in ameliorating the pesticide-induced toxicity.

A fenugreek seed extract selectively reduces spontaneous fat intake in overweight subjects

PURPOSE

Fenugreek seeds (Trigonella foenum-graecum L.) have long been used as a herbal medicine for treating metabolic and nutritive dysfunctions. They have been shown to modulate feeding behaviour in animals. We have recently observed a selective decrease in fat consumption in healthy normal weight volunteers treated with a hydro-alcoholic seed extract. However, strong clinical data on the effects of fenugreek seeds on energy intake are lacking, especially in overweight individuals. The aim of our study was to investigate the effects of a repeated administration of a fenugreek seed extract on the eating behaviour of overweight subjects.

METHODS

Thirty-nine healthy overweight male volunteers completed a 6-week double-blind randomized placebo-controlled parallel trial of a fixed dose of a fenugreek seed extract. Main endpoints were energy intake (dietary records and meal test), weight, fasting and post-absorptive glucose and insulin, appetite/satiety scores and oxidative parameters.

RESULTS

Daily fat consumption, expressed as the ratio fat reported energy intake/total energy expenditure (fat-REI/TEE), was significantly decreased in our overweight subjects administered the fenugreek seed extract relative to those receiving the placebo (fat-REI/TEE 0.26 +/- 0.02 vs. 0.30 +/- 0.01, respectively; P = 0.032). We also observed a significant decrease in the insulin/glucose ratio in subjects treated with fenugreek seed extract relative to the placebo group (0.89 +/- 0.09 vs. 1.06 +/- 0.10 mUI mmol(-1), respectively; P = 0.044). No significant effect was observed on weight, appetite/satiety scores or oxidative parameters.

CONCLUSION

The repeated administration of a fenugreek seed extract slightly but significantly decreased dietary fat consumption in healthy overweight subjects in this short-term study.

Antioxidant phytochemicals against type 2 diabetes

Dietary phytochemicals, of which polyphenols form a considerable part, may affect the risk of obesity-associated chronic diseases such as type 2 diabetes. This article presents an overview on how phytochemicals, especially polyphenols in fruits, vegetables, berries, beverages and herbal medicines, may modify imbalanced lipid and glucose homeostasis thereby reducing the risk of the metabolic syndrome and type 2 diabetes complications.

Clinical observation on trigonella foenum-graecum L. total saponins in combination with sulfonylureas in the treatment of type 2 diabetes mellitus

OBJECTIVE

To evaluate the efficacy and safety of trigonella foenum-graecum L. total saponins (TFGs) in combination with sulfonylureas (SU) in the treatment of patients with type 2 diabetes mellitus (T2DM) not well controlled by SU alone.

METHODS

Sixty-nine T2DM patients whose blood glucose levels were not well controlled by oral sulfonylureas hypoglycemic drug were randomly assigned to the treated group (46 cases) and the control group (23 cases), and were given TFGs or placebo three times per day, 6 pills each time for 12 weeks, respectively. Meanwhile, the patients continued taking their original hypoglycemic drugs. The following indexes, including effects on traditional Chinese medicine (TCM) symptoms, fast blood glucose (FBG), 2-h post-prandial blood glucose (2h PBG), glycosylated hemoglobin (HbA1c), clinical symptomatic quantitative scores (CSQS), body mass index (BMI), as well as hepatic and renal functions, were observed and compared before and after treatment.

RESULTS

The efficacy on TCM symptoms was obviously better in the treated group than that in the control group (P<0.01), and there were statistically remarkable decreases in aspect of FBG, 2h PBG, HbA1c and CSQS in the treated group as compared to those in the control group (P<0.05 or P<0.01), while no significant difference was found in BMI, hepatic and renal functions between the two groups (P>0.05).

CONCLUSION

The combined therapy of TFGs with sulfonylureas hypoglycemic drug could lower the blood glucose level and ameliorate clinical symptoms in the treatment of T2DM, and the therapy was relatively safe.

Protective Role of Trigonella hamosa Saponins Against Diabetic Perturbations and Complications in Rats

Trigonella hamosa saponins (SS) were purified using Sephadex LH-20. The effects of SS on diabetes, lipid profiles and glucose homeostasis were investigated by supplementation of the diet of rats with SS, which countered the adverse, harmful effects of chronic diabetes by improving insulin synthesis, secretion and action, enhancing lipid and protein metabolism, and removing the oxidative stress concomitant with glucose homeostasis.

Effects of aqueous extracts of medicinal plants on MNNG-treated rat hepatocytes in primary cultures

Aqueous extracts of Nigella sativa (Ranunculaceae) (Ns), Teucrium polium (Labiatae) (Tp) and Trigonella foenum-graecum (Fabaceae) (Tf) have been traditionally used to treat inflammations, liver disorders, and arthritis. Experimentally, it has been demonstrated that these herbs possess antioxidant, anti-inflammatory and hepatoprotective properties. To evaluate their in vitro toxicological properties and potential antimutagenic effects aqueous extracts of the three plants were tested in primary rat hepatocyte cultures against N-methyl-N'-nitro-N-nitrosoguanidine. The extracts were applied before, during and after application of MNNG to discriminate between different mechanisms of action. Tp itself significantly increased apoptosis, but in the combined treatment with MNNG significantly reduced it. Post-treatment with Ns or combined treatment with Tf significantly reduced the percentages of necrotic cells. The three plant extracts themselves significantly increased the frequency of chromosomal aberrations. Summarizing, our results suggest that aqueous extracts of the three herbs have neither cytoprotective nor antimutagenic activity, instead there is evidence for a mutagenic potential.

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

Trigonella foenum-graecum (fenugreek) seeds have been documented as a traditional plant treatment for diabetes. In the present study, the antidiabetic properties of a soluble dietary fibre (SDF) fraction of T. foenum-graecum were evaluated. Administration of SDF fraction (0 x 5 g/kg body weight) to normal, type 1 or type 2 diabetic rats significantly improved oral glucose tolerance. Total remaining unabsorbed sucrose in the gastrointestinal tract of non-diabetic and type 2 diabetic rats, following oral sucrose loading (2 x 5 g/kg body weight) was significantly increased by T. foenum-graecum (0 x 5 g/kg body weight). The SDF fraction suppressed the elevation of blood glucose after oral sucrose ingestion in both non-diabetic and type 2 diabetic rats. Intestinal disaccharidase activity and glucose absorption were decreased and gastrointestinal motility increased by the SDF fraction. Daily oral administration of SDF to type 2 diabetic rats for 28 d decreased serum glucose, increased liver glycogen content and enhanced total antioxidant status. Serum insulin and insulin secretion were not affected by the SDF fraction. Glucose transport in 3T3-L1 adipocytes and insulin action were increased by T. foenum-graecum. The present findings indicate that the SDF fraction of T. foenum-graecum seeds exerts antidiabetic effects mediated through inhibition of carbohydrate digestion and absorption, and enhancement of peripheral insulin action.

Effect of food seasoning spices mixture on biomarkers of oxidative stress in tissues of fructose-fed insulin-resistant rats

High fructose feeding in normal rats induces insulin resistance and also facilitates oxidative damage. The present study examines the effects of a spices mixture (SM) on oxidative stress markers and antioxidant potential in tissues of high fructose-fed insulin-resistant rats. Male Wistar rats received a semisynthetic diet containing either 60% fructose or 60% starch. SM administration at three different doses (10, 30, and 50 mg/day per rat) was initiated orally 15 days later and continued for the next 30 days. After the total experimental period of 45 days, peroxidation of lipids and antioxidant status in liver and kidney were quantified. Fructose-treated rats showed increased levels of peroxidation indices such as thiobarbituric acid-reactive substances and lipid hydroperoxides in tissues. The condition was associated with an inadequate antioxidant system. Administration of SM along with fructose diet reduced the levels of peroxidation markers in tissues and improved the antioxidant status. The positive effect of SM on the oxidant-antioxidant balance could be attributed to the active constituents of the different spices present in the mixture.

Steroidal Saponins from the Seeds ofTrigonella HamosaL

Two new furostane saponins named hamoside A and B were isolated from the 80% ethanolic extract of the defatted seeds of Trigonella hamosa L. On the basis of chemical evidence and spectral analysis (IR,1H NMR,13C NMR, HSQC, HMBC and positive ion MS), hamoside A (1) was established as (22ξ)-2α, 3β, 26-triol-3-O-β-D-galactopyranosyl-(1→4)-O-β-D-glucopyranosyl-(1→2)-O-α-rhamnopyranosyl-(1→4)-O-β-D-xylopyranoside-furost-5-ene, and hamoside B (2) as (22ξ)-2α, 3β, 26-triol-3-O-β-D-galactopyranosyl-(1→4)-O-β-D-glucopyranosyl-(1→4)-O-β-D-xylopyranoside-furost-5-ene.