Antidiabetic and neuroprotective effects of Trigonella foenum-graecum seed powder in diabetic rat brain

Diabetes mellitus and Alzheimer's disease: Understanding disease mechanisms, their correlation, and promising dual activity of selected herbs

ETHNOPHARMACOLOGICAL RELEVANCE

This review explores the link between Type 2 Diabetes Mellitus (T2DM) and diabetes-induced Alzheimer's disease (AD). It emphasizes the shared pathophysiological links and mechanisms between the two conditions, focusing on reduced insulin levels and receptors, impaired glucose metabolism, insulin resistance, mitochondrial dysfunction, and oxidative damage in AD-affected brains-paralleling aspects of T2DM. The review suggests AD as a "diabetes of the brain," supported by cognitive enhancement through antidiabetic interventions. It focuses on the traditionally used Indian herbs as a means to manage both conditions while addressing developmental challenges.

AIM OF THE STUDY

This study explores the DM-AD connection, reviewing medicinal herbs with protective potential for both ailments, considering traditional uses and developmental challenges.

MATERIALS AND METHODS

Studied research, reviews, and ethnobotanical and scientific data from electronic databases and traditional books.

RESULTS

The study analyzes the pathophysiological links between DM and AD, emphasizing their interconnected factors. Eight Ayurvedic plants with dual protective effects against T2DM and AD are thoroughly reviewed with preclinical/clinical evidence. Historical context, phytoconstituents, and traditional applications are explored. Innovative formulations using these plants are examined. Challenges stemming from phytoconstituents' physicochemical properties are highlighted, prompting novel formulation development, including nanotechnology-based delivery systems. The study uncovers obstacles in formulating treatments for these diseases.

CONCLUSION

The review showcases the dual potential of chosen medicinal herbs against both diseases, along with their traditional applications, endorsing their use. It addresses formulation obstacles, proposing innovative delivery technologies for herbal therapies, while acknowledging their constraints. The review suggests the need for heightened investment and research in this area.

A Comprehensive Review of Moroccan Medicinal Plants for Diabetes Management

Moroccan flora, renowned for its diverse medicinal plant species, has long been used in traditional medicine to manage diabetes. This review synthesizes ethnobotanical surveys conducted during the last two decades. Among these plants, 10 prominent Moroccan medicinal plants are evaluated for their phytochemical composition and antidiabetic properties through both in vitro and in vivo studies. The review encompasses a comprehensive analysis of the bioactive compounds identified in these plants, including flavonoids, phenolic acids, terpenoids, and alkaloids. Phytochemical investigations revealed a broad spectrum of secondary metabolites contributing to their therapeutic efficacy. In vitro assays demonstrated the significant inhibition of key enzymes α-amylase and α-glucosidase, while in vivo studies highlighted their potential in reducing blood glucose levels and enhancing insulin secretion. Among the ten plants, notable examples include Trigonella foenum-graecum, Nigella Sativa, and Artemisia herba-alba, each showcasing distinct mechanisms of action, such as enzymatic inhibition and the modulation of glucose metabolism pathways. This review underscores the necessity for further chemical, pharmacological, and clinical research to validate the antidiabetic efficacy of these plants and their active compounds, with a view toward their potential integration into therapeutic practices.

Antidiabetic potential of fenugreek (Trigonella foenum-graecum): A magic herb for diabetes mellitus

Fenugreek (Trigonella foenum-graecum) is a widely grown dietary herb in Asia, and its seeds are traditionally used for several diseases, including diabetes. The seeds and leaves possess a variety of compounds that play an important role in regulating their hypoglycemic effect. However, so far, no extensive systematic review exists on its antidiabetic effect, highlighting the molecular mechanisms and isolated compounds. The purpose of this review is to summarize the preclinical and clinical antidiabetic properties of fenugreek and its isolated compounds by focusing on underlying mechanisms. PubMed, Google Scholar, Science Direct, and Scopus databases were searched to retrieve articles until June, 2024. Preclinical studies demonstrated that the antidiabetic effect of fenugreek was mostly associated with enhanced glucose transporter type-4 (GLUT4) translocation and hexokinase activity, decreased glucose-6-phosphatase and fructose-1,6-bisphosphatase activities, inhibited α-amylase and maltase activities, protected β cells, and increased insulin release. Furthermore, few studies have reported its role as a glucagon-like peptide-1 (GLP-1) modulator, 5'-AMP-activated kinase (AMPK) activator, and dipeptidyl peptidase-IV (DPP-IV) inhibitor. Further clinical trials showed that fenugreek seeds improved blood glucose levels, insulin resistance, insulin sensitivity, and lipid profiles. This study highlights significant evidence of the antidiabetic effect of fenugreek and its isolated compounds; therefore, it could be a potential therapy for diabetes.

Unlocking the anti-diabetic potential of Gymnema sylvestre, Trigonella foenum-graecum, and their combination thereof: An in-vivo evaluation

The current study aimed to explore the anti-diabetic effect of aqueous extracts of Gymnema sylvestre, Trigonella foenum-graecum and mixture of both the plants in alloxan-induced diabetic rabbits. A total of 30 rabbits were grouped into six equal groups as: normal control, diabetic control, diabetic treated with 300 mg/kg body weight (bw) G. sylvestre, diabetic treated with 300 mg/kg bw T. foenum-graecum, diabetic treated with 300 mg/kg bw mixture of both the plants and diabetic treated with 500 mg/kg bw metformin for 4 weeks. Diabetes was induced to all the study group animals except normal control by intravenous administration of alloxan monohydrate (80 mg/kg bw). Blood glucose was measured by glucometer and other biochemical parameters were determined through various kit methods. Serum insulin was measured through ELISA kit method. Results showed that both the plants and metformin significantly (p < .05) decreased the fasting blood glucose. Hypoglycemic activity of aqueous extract of G. sylvestre and metformin was found slightly higher than aqueous extract of T. foenum-graecum and the mixture of both the plants. However, a significant (p < .05) rise in insulin secretion was observed in studied plants extract treated rabbits. Serum urea, creatinine, and liver enzymes were found reduced significantly (p < .05) in treated rabbits whereas packed cell volume was also returned to normal in treated animals as compared to control group. The study concluded that G. sylvestre and T. foenum-graecum extracts have comparable effects with metformin in normalizing the blood glucose level and have more pronounced effect than metformin in restoring the serum biochemical parameters to normal levels. Hence, these plants may be the good alternative medicine in managing the diabetes mellitus.

Fenugreek seed powder protects mice against arsenic-induced neurobehavioral changes

The current study was designed to evaluate the protective effect of fenugreek seed powder against As-induced neurobehavioral and biochemical perturbations using a mouse model. Mice exposed to arsenic at 10 mg/kg body weight showed development of anxiety-like behavior and memory impairment compared to control mice in elevated plus maze and Morris water maze tests, respectively. A significantly decreased acetyl and butyrylcholinesterase, superoxide dismutase and glutathione reductase activities and brain-derived neurotrophic factor levels were found in the brain of arsenic-exposed mice compared to control mice. Interestingly, supplementation of fenugreek seed powder to arsenic-treated mice significantly restored the activity of cholinesterase and antioxidant enzymes (e.g. superoxide dismutase, glutathione reductase) as well as brain-derived neurotrophic factor levels in the brain tissue of arsenic-exposed mice. Consequently, reduced anxiety-like behavior, improved learning and memory were observed in fenugreek supplemented arsenic treated mice compared to only arsenic-exposed mice group. Thus, this study suggests that fenugreek seed powder reduces arsenic-induced neurotoxicity in mice.

Neuroprotective efficacy of 4-Hydroxyisoleucine in experimentally induced intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a severe form of brain injury, which is a major cause of mortality in humans. Hydrocephalus and cerebral hematoma lead to severe neurological deficits. A single autologous blood (ALB) injection in rats' brains induces hemorrhage and other conditions that regularly interfere with the standard treatment of several cellular and molecular pathways. Several studies have found that IGF-1/GLP-1 decreases the production of inflammatory markers in peripheral tissues, while some have found that they also have pro-inflammatory functions. Since these receptors are down-regulated in hemorrhagic situations, we looked into the potential neuroprotective effect of 4-hydroxyisoleucine (4-HI); 50 mg/kg and 100 mg/kg, an active compound Trigonellafoenum-graecum, on post-hemorrhagic deficits in rats. Long-term oral administration of 4-HI for 35 days has improved behavioral and neurochemical deficits and severe pathological changes and improved cellular and molecular markers, apoptotic markers in the ALB-induced ICH experimental model.

Furthermore, the findings revealed that 4-HI also improved the levels of other neurotransmitters (Ach, DOPA, GABA, glutamate); inflammatory cytokines (TNF-alpha, IL-1β, IL-17), and oxidative stress markers (MDA, nitrite, LDH, AchE, SOD, CAT, GPx, GSH) in the brain when evaluated after Day 35. There is no proven treatment available for the prevention of post-brain hemorrhage and neurochemical malfunction; available therapy is only for symptomatic relief of the patient. Thus, 4-HI could be a potential clinical approach for treating post-brain haemorrhage and neurochemical changes caused by neurological damage. Furthermore, 4-HI may be linked to other standard therapeutic therapies utilized in ICH as a potential pharmacological intervention.

Effect of natural products on diabetes associated neurological disorders

Diabetes mellitus, a metabolic disorder, is associated with neurological complications such as depression, anxiety, hypolocomotion, cognitive dysfunction, phobias, anorexia, stroke, pain, etc. Traditional system of medicine is long known for its efficient management of diabetes. The current review discusses the scope of some common medicinal herbs as well as secondary metabolites with a special focus on diabetes-mediated central nervous system complications. Literatures suggest that natural products reduce diabetes-mediated neurological complications partly by reducing oxidative stress and/or inflammation or apoptosis in certain brain regions. Natural products are known to modulate diabetes-mediated alterations in the level of acetylcholinesterase, choline acetyltransferase, monoamine oxidase, serotonin receptors, muscarinic receptors, insulin receptor, nerve growth factor, brain-derived neurotrophic factor, and neuropeptide in brain. Further, there are several natural products reported to manage diabetic complications with unknown mechanism. In conclusion, medicinal plants or their secondary metabolites have a wide scope and possess therapeutic potential to effectively manage neurological complications associated with chronic diabetes.

Memory Improvement Effect of Ethanol Garlic (A. sativum) Extract in Streptozotocin-Nicotinamide Induced Diabetic Wistar Rats Is Mediated through Increasing of Hippocampal Sodium-Potassium ATPase, Glutamine Synthetase, and Calcium ATPase Activities

Studies suggest that garlic (A. sativum) improves memory dependent on the hippocampus. However, the effect of ethanol garlic extract on hippocampus Na⁺/K⁺ ATPase, Ca²⁺ ATPase, and glutamine synthetase (GS) activities as possible mechanisms in memory improvement in diabetic Wistar rats has not been reported. Twenty-four male Wistar rats weighing 200-250 g were divided into three groups with 8 rats each. Group (A), normal control rats, and Group (B), diabetic rats, received 1 ml of normal saline; diabetic rats in Group (C) received 1000 mg/kg of garlic extract orally for 21 days. Hyperglycemia was induced by a single intraperitoneal injection of streptozotocin 60 mg/kg followed by 120 mg/kg nicotinamide while extraction of garlic was done by cold maceration method. Memory was tested in all groups. After that, the rats were sacrificed, the brain was removed, and the hippocampi were carefully excised and then homogenized. Activities of Na⁺/K⁺ ATPase, calcium ATPase, and GS were analyzed from the homogenate. Results showed improvement in memory and a significant increase (P < 0.05) in hippocampus Na⁺/K⁺ ATPase, Ca²⁺ ATPase, and GS activities in diabetic rats treated with garlic extract. In conclusion, the increased activity of hippocampus Na⁺/K⁺ ATPase, calcium ATPase, and glutamine synthetase may account for the memory improvement.

Effects of Saponin from Trigonella Foenum-Graecum Seeds on Dyslipidemia

BACKGROUND

Saponins identified from fenugreek (Trigonella foenum-graecum) seeds are reported effective on dyslipidemia. However, the definite mechanism is still not elucidated systematically. In this study, we evaluate the effects of saponin extract on cholesterol absorption, metabolism, synthesis, and reverse cholesterol transport in vivo.

METHODS

Saponin extract was prepared according to a craft established in our previous study. After the establishment of dyslipidemia model, 40 male Sprague-Dawley rats were divided into five groups, namely the control group (normal diet plus normal saline), HFD group (high fat diet plus normal saline), Lipitor group (high fat diet plus Lipitor (2 mg/kg)), and L, M, and H-saponin groups (high fat diet plus saponin in dosages of 6, 12, and 24 mg/kg, respectively). Rats were sacrificed at the end of the 9th week after treatment. Biochemical characteristics of rats were tested, histopathological sections of liver tissue were observed, and the protein and mRNA expression of related factors of cholesterol in the intestine and liver were determined. One-way ANOVA test (SPSS software version 11.5, Chicago, IL, USA) was used to determine statistically significant differences between the HFD and other groups.

RESULTS

In saponin groups, the serum lipid, bile acid efflux, anti-peroxide activities, and lipid area of liver tissue improved. Cholesterol 7alpha-hydroxylase and scavenger receptor class B type I elevated in the liver. 3-hydroxy-3-methylglutaryl coenzyme A reductase levels were suppressed in both the serum and liver. However, significant cholesterol efflux was not found and Niemann-Pick C1-Like 1 levels elevated in the intestine.

CONCLUSION

The mechanisms of saponin in Fenugreek effect on ameliorating dyslipidemia are probably related to accelerated cholesterol metabolism, inhibited cholesterol synthesis, and facilitated reverse cholesterol transport, but not cholesterol absorption.

Recent Update on the Role of Chinese Material Medica and Formulations in Diabetic Retinopathy

Diabetes mellitus is one of the most frequent endocrine disorders, affecting populations worldwide. Diabetic retinopathy (DR) is the most frequent microvascular complication of diabetes in patients aged 20 and over. Major complications of DR include intraocular neovascularization, inter-retinal edema, hemorrhage, exudates and microaneurysms. Therefore, timely medical attention and prevention are required. At present, laser-assisted therapy and other operational procedures are the most common treatment for DR. However, these treatments can cause retinal damage and scarring. Also, use of the majority of traditional medicines is not supported by clinical evidence. However, due to accumulating scientific evidence, traditional natural medications may assist in delaying or preventing the progression of DR. This review focuses on evidence for the role of traditional natural medicines and their mechanisms of action and pharmacological test results in relation to the progression of DR.

Toxicological properties of fenugreek (Trigonella foenum graecum)

Fenugreek (Trigonella foenum graecum), used as traditional medicine and natural additive food, has been shown to exert significant antiatherogenic, antidiabetic, antianorexic, antioxidant, anticarcinogenic, antihyperlipidemic, galactogogue and anti-inflammatory effects in several human and animal models. Besides, several medicinal pharmaceutical and nutraceutical properties, fenugreek have toxic effects as well. The aim of this review is discuss the cumulative evidence, which suggests that consumption of fenugreek induced some serious toxicological side effects. In this review, many teratogenic effects of fenugreek, from congenital malformations to death, were reported in human, rodent, rabbit, and chick. Moreover, results obtained in rats, mice and rabbits show a testicular toxicity and anti-fertility effects in male associated with oxidative stress and DNA damage, as well as anti-fertility, antiimplantation and abortifacient activity in females related to saponin compound of fenugreek which suggest that fenugreek is not recommended for use during pregnancy. Indeed, the consumption of fenugreek should be avoided for persons having peanut and chickpeas allergy because of possible cross-reactivity as well as chronic asthma. Accumulating evidence suggest also that fenugreek may have neurodevelopmental, neurobehavioral and neuropathological side effects. It is suggested that future studies would be conducted to identify molecular and cellular mechanisms underlying the fenugreek toxicological properties.

Development of an antidiabetic formulation (ADJ6) and its inhibitory activity against α-amylase and α-glucosidase

There has recently been much advancement in the diagnosis, treatment, and research of metabolic disorders, especially diabetes. Current research around the world is focused on finding an alternative source of treatment from natural resources for diabetic management, apart from the available synthetic medicines. The present study is a preliminary study of a polyherbal formulation using edible natural resources and an assessment of its antidiabetic activity. The formulation was screened for its phytochemical constituents, total phenols, flavonoids, and vitamin C content. It was also analyzed for its inhibitory effect against the digestive enzymes α-amylase and α-glucosidase, compared with the standard drug acarbose. The formulation showed the presence of major constituents such as steroids, cardiac glycosides, phenols, flavonoids, and saponins. It also had a high level of phenols (340 ± 2.5 mg/g), flavonoids (235.4 ± 8.3 mg/g), and vitamin C (470.8 ± 16.6 mg/g), and showed a half-maximal inhibitory concentration (IC50) value of 0.41 ± 0.03 mg/mL and 0.51 ± 0.01 mg/mL for amylase and glucosidase, respectively. The results showed that ADJ6 had a significant inhibitory activity on α-amylase and α-glucosidase; however, its inhibitory activity was less than that of acarbose. The plants that are formulated in ADJ6 possess potent antidiabetic activity. Thus, we found that ADJ6 is a potent lead for effective diabetic management; however, an evaluation of the formulation must be illustrated using an in vivo model.

Trigonella foenum-graecum water extract improves insulin sensitivity and stimulates PPAR and γ gene expression in high fructose-fed insulin-resistant rats

BACKGROUND

Insulin resistance is the main defect associated with the metabolic syndrome. In obesity, the decreased adiponectin levels and elevation of plasma-free fatty acids are the main factors associated with insulin resistance. In this study, we evaluated the effect of trigonella foenum-graecum (TFG) extract on insulin sensitivity in high fructose-fed insulin-resistant rats.

MATERIALS AND METHODS

Experimental rats were fed with a high fructose diet for eight weeks. After the first six weeks, the animals were treated with trigonella foenum-graecum extract or pioglitazone for two weeks. Serum glucose, triglycerides, cholesterol, and HDL-c were measured. The insulin and adiponectin levels were assayed by the enzyme-linked immunosorbent assay (ELISA), and Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) was calculated. The plasma-free fatty acid profile was obtained by gas chromatography. PPARγ and GLUT4 gene expression were assessed by real-time polymerase chain reaction (PCR) and western blotting.

RESULTS

In the trigonella foenum-graecum- extract treated group the following results were obtained: Insulin (49.02 ± 6.93 pmol/L), adiponectin (7.1 ± 0.64 μg/ml), and triglycerides (110.3 ± 16.7 mg/dl), which were significantly different and improved compared to the control group (insulin (137 ± 34 pmol/l), adiponectin (3.9 ± 0.15 μg/ml), glucose (187 ± 15 mg/dl), and triglycerides (217 ± 18 mg/dl). Also the PPARγ gene expression was significantly increased compared to the control group.

CONCLUSION

This study demonstrates the beneficial effects of trigonella foenum-graecum extract on insulin resistance in rats fed on a high-fructose diet. At least three mechanisms are involved, including direct insulin-like effect, increase in adiponectin levels, and PPARγ protein expression.

Sodium Orthovanadate and Trigonella Foenum Graecum Prevents Neuronal Parameters Decline and Impaired Glucose Homeostasis in Alloxan Diabetic Rats

Hyperglycemia is the most important contributor in the onset and progress of diabetic complications mainly by producing oxidative stress. The present study was carried out to observe, the antihyperglycemic effect of sodium orthovanadate (SOV) and Trigonella foenum graecum seed powder (TSP) administration on blood glucose and insulin levels, membrane linked enzymes (monoamine oxidase, acetylcholinesterase, Ca2+ATPase), intracellular calcium (Ca2+) levels, lipid peroxidation, membrane fluidity and neurolipofuscin accumulation in brain of the alloxan induced diabetic rats and to see whether the treatment with SOV and TSP was capable of reversing the diabetic effects. Diabetes was induced by administration of alloxan monohydrate (15 mg/100 g body weight) and rats were treated with 2 IU insulin, 0.6 mg/ml SOV, 5% TSP in the diet and a combination of 0.2 mg/ml SOV and 5% TSP separately for three weeks. Diabetic rats showed hyperglycemia with almost four fold high blood glucose levels. Activities of acetylcholinesterase and Ca2+ATPase decreased in diabetic rat brain. Diabetic rats exhibited an increased level of intracellular Ca2+ levels, lipid peroxidation, neurolipofuscin accumulations and monoamine oxidase activity. Treatment of diabetic rats with insulin, TSP, SOV and a combined therapy of lower dose of SOV with TSP revived normoglycemia and restored the altered level of membrane bound enzymes, lipid peroxidation and neurolipofuscin accumulation. Our results showed that lower doses of SOV (0.2 mg/ml) could be used in combination with TSP in normalization of altered metabolic parameters and membrane linked enzymes without any harmful side effect.

Neonatal hyperglycemia induces oxidative stress in the rat brain: the role of pentose phosphate pathway enzymes and NADPH oxidase

Recently, the consequences of diabetes on the central nervous system (CNS) have received great attention. However, the mechanisms by which hyperglycemia affects the central nervous system remain poorly understood. In addition, recent studies have shown that hyperglycemia induces oxidative damage in the adult rat brain. In this regard, no study has assessed oxidative stress as a possible mechanism that affects the brain normal function in neonatal hyperglycemic rats. Thus, the present study aimed to investigate whether neonatal hyperglycemia elicits oxidative stress in the brain of neonate rats subjected to a streptozotocin-induced neonatal hyperglycemia model (5-day-old rats). The activities of glucose-6-phosphate-dehydrogenase (G6PD), 6-phosphogluconate-dehydrogenase (6-PGD), NADPH oxidase (Nox), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSHPx), the production of superoxide anion, the thiobarbituric acid-reactive substances (TBA-RS), and the protein carbonyl content were measured. Neonatal hyperglycemic rats presented increased activities of G6PD, 6PGD, and Nox, which altogether may be responsible for the enhanced production of superoxide radical anion that was observed. The enhanced antioxidant enzyme activities (SOD, CAT, and GSHPx) that were observed in neonatal hyperglycemic rats, which may be caused by a rebound effect of oxidative stress, were not able to hinder the observed lipid peroxidation (TBA-RS) and protein damage in the brain. Consequently, these results suggest that oxidative stress could represent a mechanism that explains the harmful effects of neonatal hyperglycemia on the CNS.

Centella asiatica Attenuates Diabetes Induced Hippocampal Changes in Experimental Diabetic Rats

Diabetes mellitus has been reported to affect functions of the hippocampus. We hypothesized that Centella asiatica, a herb traditionally being used to improve memory, prevents diabetes-related hippocampal dysfunction. Therefore, the aim of this study was to investigate the protective role of C. asiatica on the hippocampus in diabetes. Methods. Streptozotocin- (STZ-) induced adult male diabetic rats received 100 and 200 mg/kg/day body weight (b.w) C. asiatica leaf aqueous extract for four consecutive weeks. Following sacrifice, hippocampus was removed and hippocampal tissue homogenates were analyzed for Na(+)/K(+)-, Ca(2+)- and Mg(2+)-ATPases activity levels. Levels of the markers of inflammation (tumor necrosis factor, TNF-α; interleukin, IL-6; and interleukin, IL-1β) and oxidative stress (lipid peroxidation product: LPO, superoxide dismutase: SOD, catalase: CAT, and glutathione peroxidase: GPx) were determined. The hippocampal sections were visualized for histopathological changes. Results. Administration of C. asiatica leaf aqueous extract to diabetic rats maintained near normal ATPases activity levels and prevents the increase in the levels of inflammatory and oxidative stress markers in the hippocampus. Lesser signs of histopathological changes were observed in the hippocampus of C. asiatica leaf aqueous extract treated diabetic rats. Conclusions. C. asiatica leaf protects the hippocampus against diabetes-induced dysfunction which could help to preserve memory in this condition.

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.

Beneficial effects of Trigonella foenum graecum and sodium orthovanadate on metabolic parameters in experimental diabetes

Oxidative stress in diabetic tissues is accompanied by high-level of free radicals with simultaneously declined antioxidant enzymes status leading to cell membrane damage. The present study was carried out to observe the effect of sodium orthovanadate (SOV) and Trigonella foenum graecum seed powder (TSP) administration on blood glucose and insulin levels, antioxidant enzymes, lipid peroxidation, pyruvate kinase, lactate dehydrogenase and protein kinase C in heart, muscle and brain of the alloxan-induced diabetic rats to see whether the treatment with SOV and TSP was capable of reversing the diabetic effects. Diabetes was induced by administration of alloxan monohydrate (15 mg/100 g body weight), and rats were treated with 2 IU insulin, 0.6 mg/ml SOV, 5% TSP in the diet and a combination of 0.2 mg/ml SOV and 5% TSP separately for 21 days. Blood glucose levels increased markedly in diabetic rats, animals treated with a combined dose of SOV and TSP had glucose levels almost comparable with controls, similar results were obtained in the activities of pyruvate kinase, lactate dehydrogenase, antioxidant enzymes and protein kinase C in diabetic animals. Our results showed that lower doses of SOV (0.2 mg/ml) could be used in combination with TSP to effectively reverse diabetic alterations in experimental diabetes.