Effect of fenugreek (Trigonella foenum-graecum L) seeds on serum parameters in normal and streptozotocin-induced diabetic rats

Role of Fenugreek, Cinnamon, Curcuma longa, Berberine and Momordica charantia in Type 2 Diabetes Mellitus Treatment: A Review

Type 2 diabetes mellitus (T2DM) is a complex disease that has become a major global health concern. Given the efficacy of antidiabetic drugs, pharmacological therapy is considered the first-line treatment of T2DM; however, due to their potential side effects and high costs, new and cost-effective treatments with minimal side effects are needed. Medicinal plants have been used for centuries as part of traditional medicine to treat T2DM. Among these, fenugreek, cinnamon, Curcuma longa, berberine, and Momordica charantia have demonstrated different degrees of hypoglycemic activity in clinical studies and animal models. Therefore, the aim of this review is to synthesize the mechanisms of action of five medicinal plants, as well as the experimental and clinical evidence of their hypoglycemic activity from the published literature.

Anti-diabetic Potential of some Spices Commonly used in Diet with other Pharmacological Activities: A Review

Background::

Diabetes mellitus is a chronic metabolic disorder, the prevalence of which is increasing alarmingly throughout the world and imposes a serious impact on the health of the population as well as national economies. Effective management and primary prevention are essential to decrease the burden of diabetes faced by all nations. Although different therapies are available for diabetes, no known therapy can completely cure the disease, and many of them have a number of side effects with other limitations like long-term treatment, expensiveness, and less availability. Hence, the present review has given an emphasis on common dietary materials to find out a readily available source of anti-diabetic agents.

Objective:

The purpose of this work is to explore the anti-diabetic properties of certain spices which are most frequently used in Bangladesh and reported for their use in traditional treatment of diabetes and/or investigated scientifically for anti-diabetic activity.

Methods:

Two electronic databases, namely Pub Med and Google Scholar, were used for conducting a comprehensive search to collect information and data.

Results:

In this review, a total of 10 spices have been compiled with a brief description of their origin, part used, chemical constituents, mechanism of action, methods of experiment, model animals, and reported beneficial effects in diabetes with other pharmacological activities.

Conclusion:

The observed results of this study indicate the possibility of developing a therapeutic strategy called alternative and complementary medicine for the management of diabetes. The results also provide a starting point for researchers working with bioactive dietary plants with anti-diabetic potential.

Some Common Medicinal Plants with Antidiabetic Activity, Known and Available in Europe (A Mini-Review)

Diabetes is a metabolic disease that affected 9.3% of adults worldwide in 2019. Its co-occurrence is suspected to increase mortality from COVID-19. The treatment of diabetes is mainly based on the long-term use of pharmacological agents, often expensive and causing unpleasant side effects. There is an alarming increase in the number of pharmaceuticals taken in Europe. The aim of this paper is to concisely collect information concerning the few antidiabetic or hypoglycaemic raw plant materials that are present in the consciousness of Europeans and relatively easily accessible to them on the market and sometimes even grown on European plantations. The following raw materials are discussed in this mini-review: Morus alba L., Cinnamomum zeylanicum J.Presl, Trigonella foenum-graecum L., Phaseolus vulgaris L., Zingiber officinale Rosc., and Panax ginseng C.A.Meyer in terms of scientifically tested antidiabetic activity and the presence of characteristic biologically active compounds and their specific properties, including antioxidant properties. The characteristics of these raw materials are based on in vitro as well as in vivo studies: on animals and in clinical studies. In addition, for each plant, the possibility to use certain morphological elements in the light of EFSA legislation is given.

A novel UPLC-MS/MS method for simultaneous quantification of trigonelline, 4-hydroxyisoleucine, and diosgenin from Trigonella foenum-graecum extract: Application to pharmacokinetic study in healthy and type 2 diabetic rats

Trigonelline (TR), 4-hydroxyisoleucine (4-HI), and diosgenin (DG) are the main bioactives of the purified standardized extract of the popular plant Trigonella foenum-graecum L. (TFG), and it has been proven effective for the treatment of various diseases. However, to the best of our knowledge, no study has investigated the pharmacokinetic parameters of purified standardized T. foenum-graecum extract in normal and diabetic Wistar rats. The present study has developed and validated a rapid, reliable, and sensitive simultaneous ultra-performance liquid chromatography MS method to estimate these bioactives. The chromatographic separation was achieved using methanol, acetonitrile, and 0.1% formic acid with the ideal gradient flow system on a BEH Shield RP 18 column. A positive electrospray ionization mode was selected to estimate m/z values of TR (138.14 > 94.63), 4-HI (148.19 > 74.08), and DG (415.54 > 271.33). The method was robust and reproducible over the linearity range of 60-5000, 6-5000, and 15-5000 ng/mL for TR, 4-HI, and DG, respectively. Using this novel validated method, we investigated the pharmacokinetic parameters of bioactives using Phoenix WinNonlin version 8.0 (Certera) in normal and diabetic rats. The assay was successfully applied for the estimation of pharmacokinetic parameters using noncompartmental analysis. This investigation shows that the absorption rate increased, whereas distribution and elimination processes slowed down in diabetic rats compared with normal rats.

Ethnobotanical Survey of Medicinal Plants Used by Traditional Healers to Treat Diabetes in the Taza Region of Morocco

Type 2 diabetes is one of the noncommunicable diseases that is becoming a pandemic in Africa. In Morocco, traditional healers have started to use herbal medicines for the treatment of diabetes either individually or in combination with food. The current study aimed to perform an ethnobiological survey of antidiabetic plants use in the Taza region of Morocco. A total of 193 traditional healers were interviewed using a semistructured questionnaire. Data collected were analyzed utilizing the use value (UV), fidelity level (FL), and relative frequency citation (RFC) indices. Forty-six plant species belonging to 28 families were recorded for the treatment of diabetes in the Taza region of Morocco. The most frequently cited plant species are Salvia officinalis, Marrubium vulgare, and Ajuga iva. Lamiaceae, Asteraceae, and Fabaceae were the most reported families. Leaves are the most used part of plants to prepare drugs, the decoction is the preferred mode of preparation, and remedies are often administered orally. Interestingly, Cytisus battandieri, Urginea maritima, Plantago ovata, and Ziziphus jujuba were reported as new medicinal plants used to treat diabetes in the Taza region of Morocco. People in the Taza region still rely on indigenous plants for their basic healthcare needs. Further research should be carried out to validate the antidiabetic effect of the newly reported plant species. This validation can be investigated by the determination of bioactive compounds and evaluation of their in vitro and in vivo antidiabetic effects.

Engineering Bacillus subtilis Isoleucine Dioxygenase for Efficient Synthesis of (2S,3R,4S)-4-Hydroxyisoleucine

Isoleucine dioxygenase (IDO)-catalyzed hydroxylation of isoleucine is a promising method for the synthesis of the diabetic drug (2S,3R,4S)-4-hydroxyisoleucine [(2S,3R,4S)-4-HIL]. However, the low activity of IDO significantly limits its practical application. In this work, a high-throughput screening method was developed and directed evolution was performed on the IDO from Bacillus subtilis, resulting in a double mutant with improvements in specific activity, protein expression level, and fermentation titer of 3.2-, 2.8-, and 9.4-fold, respectively. l-Isoleucine (228 mM) was completely converted to (2S,3R,4S)-4-HIL by the best variant with a space-time yield of up to 80.8 g L^-1 d^-1, which is the highest record reported so far. With a further increase of the substrate loading to 1 M, a high conversion of 91% could also be achieved. At last, enzymatic synthesis of (2S,3R,4S)-4-HIL was successfully carried out on a 3 L scale, indicating tremendous potential of the IDO variant I162T/T182N for green and efficient production of (2S,3R,4S)-4-HIL.

Indian Traditional medicinal plants as a source of potent Anti-diabetic agents: A Review

Objective

The present review aims to provide an overview of traditional medicinal plants known to be of anti-diabetic potential.

Methods

A literature search was conducted using the scientific databases including PubMed, EMBASE and google scholar and a total of fifty herbs have been described and their possible mechanism of anti-diabetic action has been mentioned. Among them, in-depth discussion on five most potent anti-diabetic herbs has been provided with respect to their mechanism of action, in-vivo studies and clinical efficacies.

Results

The present review has highlighted the usefulness of the herbal source for the treatment and management of diabetes mellitus. With the help of previous literature published on In-vivo animal studies and human clinical studies; the effectiveness of Gymnema sylvestre, Momordica charantia, Trigonella foenum graecum, Tinospora cordifolia and Curcuma longa in the treatment and management of Diabetes has been proved.

Conclusion

Based on this review it can be concluded that herbs can serve as more efficient, safer, and cost-effective adjuvant therapy in the management and treatment of diabetes. Further investigations mainly focusing on the isolation of phytocompounds from these herbs can lead to the discovery of newer antidiabetic agents.

Investigation of anti-diabetic plants used among the ethnic communities of Kanpur division, India

ETHNO PHARMACOLOGICAL RELEVANCE

Kanpur division is one of the large areas of India with diverse traditional medicinal heritage. In this area, a large number of people suffer from diabetes mellitus. People in this area handle diabetes with herbal and modern medicinal treatments. However, folk knowledge for the treatment of diabetes is not documented.

AIM OF THE STUDY

To document and promulgate the enormous indigenous knowledge of therapeutic importance of herbal plants used by the local practitioners for diabetes mellitus.

MATERIALS AND METHOD

Total 44 local practitioners (28 male and 16 female) were interviewed through a questionnaire. The medicinal plants suggested by the practitioners were identified by the taxonomist, and plant specimens were preserved.

RESULTS

Thirty-five species of plants, belonging to 24 families, were suggested by 44 local healers of Kanpur division. The fidelity level (FL), use values (UV) and relative frequency of citation (RFC) for each plant have been analyzed. The UV, FL, and RFC values of the recorded plants ranged between 0.97 to 0.23, 82.7%-24.1% and 0.327 to 0.067, respectively. Leguminosae family dominated with 14.28% of the total plants. The highest used life form was recorded as tree (43%) while the most widely used plant part was leaf (30.6%). The highest UV, FL, and RFC were recorded for the Aloe vera L. (0.97), Syzygium cumini L. (82.7%) and Momordica charantia L. (0.327) respectively.

CONCLUSION

The present study exhibits the knowledge and use of anti-diabetic plants adopted by the ethnic communities of Kanpur division. Future pharmacological investigations are required to test the potency and efficacy of herbal treatments. There is also a need for sustainable use and conservation of these medicinally useful plants.

Biofortification of chromium in fenugreek seeds

BACKGROUND

Fenugreek and chromium are known to have anti-diabetic properties and this has been well demonstrated by multiple studies. Researches have been undertaken to study thebiofortification of chromium (Cr3+) in fenugreek. Some of the researchers have studied the biofortification from the soil irrigated with tannery waste water or from soil amended by tannery-sludge, with a view of enhancing the anti-diabetic effect of fenugreek plants. The present research work was also undertaken to increase the chromium content of fenugreek seeds, but through direct treatment of chromium picolinate solution to fenugreek seeds.

METHODS

Fenugreek seeds were procured and divided in four groups having three batches of 10 g seeds- treatment1, treatment2, control1 and control2. Control1 group was kept raw and was given no treatment and control2 group was germinated using double distilled water. Treatment1 and treatment2, on the other hand, were given treatment of 0.02 g and 0.04 g chromium picolinate solution, on first day and 0.01 g and 0.02 g chromium picolinate solution on second day, respectively. The germinated samples were then completely dried, powdered, digested with di-acid mixture and assayed using Inductively Coupled Plasma optical emission spectrometry method for chromium content. The treatment1 sample was selected for further nutritional analysis along with control1 and control2 group to compare the nutritional composition of raw, germinated and chromium treated fenugreek seed flour. Fifteen sprouts from treatment1 group (treatment1A group) and fifteen sprouts from control2 group (control3 group) were sown in earthen pots for the analysis of chromium content in seeds of new plants.

RESULTS

The fenugreek seeds treated with two different concentrations of chromium picolinate viz. treatment1 and treatment2 group attained 55 and 80 times higher chromium content as compared to control2 group, respectively. All the estimated minerals and bioactive compounds were significantly high (p ≤ 0.01) in germinated fenugreek seed flour and chromium treated fenugreek seed flour compared to raw fenugreek seed flour. Germinated fenugreek seed flour and chromium treated fenugreek seed flour were statistically comparable to each other in respect of all the parameters analysed. Hence, it was evident that enriching fenugreek seeds with chromium, did not affect the nutritional content of fenugreek seed by any mean. Also, there was no significant difference between the chromium content in seeds of control3 group and T1A group.

CONCLUSIONS

Treatment of fenugreek seeds with chromium solution seems to be an efficient and safe method for increasing their chromium concentration as compared to application of chromium to the soil for biofortification with minimal to no chance of chromium accumulation and inheritance in next generation plants. However, there is a need of more research to see how reliable these observations would be when different chromium salts and/or varied chromium concentration are used.

Reconstitution of TCA cycle involving l-isoleucine dioxygenase for hydroxylation of l-isoleucine in Escherichia coli using CRISPR-Cas9

l-isoleucine dioxygenase (IDO) is an Fe (II)/α-ketoglutarate (α-KG)-dependent dioxygenase that specifically converts l-isoleucine (l-Ile) to (2S, 3R, 4S)-4-hydroxyisoleucine (4-HIL). 4-HIL is an important drug for the treatment and prevention of type 1 and type 2 diabetes but the yields using current methods are low. In this study, the CRISPR-Cas9 gene editing system was used to knockout sucAB and aceAK gene in the TCA cycle pathway of Escherichia coli (E. coli). For single-gene knockout, the whole process took approximately 7 days. However, the manipulation time was reduced by 2 days for each round of gene modification for multigene editing. Using the genome-edited recombinant strain E. coli BL21(DE3) ΔsucABΔaceAK/pET-28a(+)-ido (2Δ-ido), the bioconversion ratio of L-Ile to 4-HIL was enhanced by about 15% compared to E. coli BL21(DE3)/pET-28a(+)-ido [BL21(DE3)-ido] strain. The CRISPR-Cas9 editing strategy has the potential in modifying multiple genes more rapidly and in optimizing strains for industrial production.

Efficient Biosynthesis of High-Value Succinic Acid and 5-Hydroxyleucine Using a Multienzyme Cascade and Whole-Cell Catalysis

Succinic acid (SA) is applied in the food, chemical, and pharmaceutical industries. 5-Hydroxyleucine (5-HLeu) is a promising precursor for the biosynthesis of antituberculosis drugs. Here, we designed a promising synthetic route for the simultaneous production of SA and 5-HLeu by combining l-leucine dioxygenase (NpLDO), l-glutamate oxidase (LGOX), and catalase (CAT). Two bioconversion systems: "a multienzyme cascade catalysis in vitro" (MECCS) and "whole-cell catalysis system" (WCCS) were constructed. A high-activity NpLDO mutant was screened by error-prone polymerase chain reaction (PCR) and showed 6.1-fold improvement of catalytic activity. After optimization of reaction conditions, MECSS yielded 3.15 g/L SA and 3.92 g/L 5-HLeu, while the production of SA and 5-HLeu by the most effective WCSS reached 15.12 and 18.83 g/L, respectively. This is the first attempt to use ferrous iron/α-ketoglutarate-dependent dioxygenases for the simultaneous production of SA and hydroxy-amino-acid. This research provides a tool for industrial production of food of high-value products from low-cost raw materials.

The growth impairment of salinized fenugreek (Trigonella foenum-graecum L.) plants is associated to changes in the hormonal balance

Fenugreek is a legume cultivated for its medicinal value, especially in arid and semi-arid regions, where soil salinity is an increasing problem. In fact, salinity is one of the major environmental factors limiting plant growth and productivity. Plant hormones are known to play vital roles in the ability of the plants to acclimatize to varying environments by mediating growth, development, and nutrient allocation. Thus, to gain insights about the role of plant hormones in the growth responses of salinized fenugreek plants (Trigonella foenum-graecum L.), a medium-term experiment was conducted under moderate (100 mM NaCl) and high (200 mM NaCl) salinity levels. Results showed that moderate, but especially high salinity stress, impaired shoot growth, total leaf area and leaf number. Salinity also provoked a reduction in relative water content, stomatal conductance and photosynthesis-related pigments, but, surprisingly, photosynthetic rate increased in the leaves of fenugreek plants. Na accumulated in the leaves, particularly at high salinity levels, while most mineral nutrients decreased. Furthermore, important changes in the main hormone classes were observed, associated to growth reduction under salinity. The active cytokinin form, trans-zeatin, and active cytokinin and gibberellin concentrations decreased with salinity in the leaves of fenugreek plants, whereas the ethylene precursor, 1-aminocyclopropane-1-carboxylic acid, accumulated in the roots of fenugreek plants, especially at high salinity levels. Importantly, leaf abscisic acid concentrations increased under salinity, which could limit leaf transpiration to adapt growth to the stressful conditions. Therefore, plant hormones seem to play a critical role in the growth responses of fenugreek plants under salinity stress and they could have potential interest in salt tolerance programmes for this species.

Polyphenol Stilbenes from Fenugreek (Trigonella foenum-graecum L.) Seeds Improve Insulin Sensitivity and Mitochondrial Function in 3T3-L1 Adipocytes

Fenugreek (Trigonella foenum-graecum L.) is a well-known annual plant that is widely distributed worldwide and has possessed obvious hypoglycemic and hypercholesterolemia characteristics. In our previous study, three polyphenol stilbenes were separated from fenugreek seeds. Here, we investigated the effect of polyphenol stilbenes on adipogenesis and insulin resistance in 3T3-L1 adipocytes. Oil Red O staining and triglyceride assays showed that polyphenol stilbenes differently reduced lipid accumulation by suppressing the expression of adipocyte-specific proteins. In addition, polyphenol stilbenes improved the uptake of 2-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-2-deoxyglucose (2-NBDG) by promoting the phosphorylation of protein kinase B (AKT) and AMP-activated protein kinase (AMPK). In present studies, it was found that polyphenol stilbenes had the ability to scavenge reactive oxygen species (ROS). Results from adenosine triphosphate (ATP) production and mitochondrial membrane potentials suggested that mitochondria play a critical role in insulin resistance and related signaling activation, such as AKT and AMPK. Rhaponticin, one of the stilbenes from fenugreek, had the strongest activity among the three compounds in vitro. Future studies will focus on mitochondrial biogenesis and function.

Sufficient NADPH supply and pknG deletion improve 4-hydroxyisoleucine production in recombinant Corynebacterium glutamicum

Cofactor engineering is a common strategy to improve amino acid production. 4-hydroxyisoleucine (4-HIL), a nonproteinogenic amino acid, exhibits unique insulinotropic and insulin-sensitizing activities, therefore has potential medical value in treating diabetes. In our previous study, l-isoleucine (Ile) dioxygenase gene ido was overexpressed in an Ile-producing Corynebacterium glutamicum strain, and 4-HIL was de novo synthesized from glucose. In this study, to increase the NADPH supply, the endogenous NAD⁺ kinase gene ppnK and glucose-6-phosphate dehydrogenase gene zwf were co-expressed with ido. The resulting strain SL01 produced 81.12 ± 5.96 mM 4-HIL, 62% higher than the ido-mere expressing strain SN02. However, the strain SL02 co-expressing exogenous NADH kinase gene POS5 with ido grew slowly and its 4-HIL production decreased by 12%, perhaps due to the lower 2-oxoglutarate (OG) level and slightly weaker membrane permeability. To increase OG availability for 4-HIL conversion, the serine/threonine protein kinase G gene pknG was deleted and replaced by ido gene in SL02. The growth of the resulting strain SL04 was restored and 4-HIL production was improved to 84.14 ± 6.38 mM; meanwhile, the conversion ratio of Ile to 4-HIL reached up to 0.98 ± 0.01 mol/mol. Therefore, sufficient NADPH supply and OG availability may be benefit to 4-HIL de novo biosynthesis in recombinant C. glutamicum.

Effects of the fenugreek extracts on high-fat diet-fed and streptozotocin-induced type 2 diabetic mice

BACKGROUND

To study the antidiabetic effects and mechanisms of the fenugreek extracts in streptozotocin (STZ)-induced type 2 diabetic (T2DM) mice fed a high-fat diet (HFD).

METHODS

We established C57BL/6J mice model of T2DM using HFD-fed and STZ-induced method. Then, the mice were administered with two types of fenugreek extracts (E1, flavonoid and E2, stilbene glycoside) for 4 weeks and the effects on fasting blood glucose (FBG), weight, superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), and pathological indexes were investigated.

RESULTS

Administration of fenugreek extracts decreased the FBG level compared with that of the model group. Comparatively, the high-dose E2 decreased the FBG more significantly than the other treatments did. Both extracts showed an obvious antioxidant effect by increasing serum SOD and CAT activities and decreasing the MDA content. Furthermore, the high-dose E1 showed a significant difference (P < .01) compared with the model group in the three investigated indexes.

CONCLUSION

Our study demonstrated that both the flavonoid and stilbene glycoside extracts of fenugreek improved the hyperglycemia in the T2DM mice model. Moreover, the antidiabetic effects of both extracts might be due to their antioxidant activity in vivo.

Engineering a short-chain dehydrogenase/reductase for the stereoselective production of (2S,3R,4S)-4-hydroxyisoleucine with three asymmetric centers

Fenugreek is a dietary supplement for anti-aging and human health. (2S,3R,4S)-4-hydroxyisoleucine (4-HIL), which is extracted from fenugreek seeds, is expected to be a promising orally active drug for diabetes and diabetic nephropathy because of its insulinotropic effect. Although several chemical synthesis methods of 4-HIL have been proposed, these methods require multistep reactions to control the stereochemistry of 4-HIL. In this study, we modified the key enzyme 4-HIL dehydrogenase (HILDH) to overcome the biggest limitation in commercial-scale production of 4-HIL. As a result, an effective one-step carbonyl reduction to produce (2S,3R,4S)-4-HIL was successfully accomplished with strict stereoselectivity (>99% de). Mass production of (2S,3R,4S)-4-HIL by our synthetic method could have a significant contribution to the prevention of diabetes, dyslipidemia, and Alzheimer's disease. (120 words/200 words).

Phytoecdysteroids from Ajuga iva act as potential antidiabetic agent against alloxan-induced diabetic male albino rats

The present study investigated the protective effect of phytoecdysteroids extracted from the Ajuga iva plant on body weight changes, blood glucose, insulin total protein, blood urea nitrogen (BUN), creatinine, triglycerides (TG), cholesterol, lipid peroxidation, antioxidant enzymes, pancreatic histopathology and hexokinase-I expression in the alloxan-induced diabetic rats. Experimental diabetes was induced following 15day intraperitoneal administration of alloxan. The rats were divided into four groups. Group I served as a sham group, and group II served as the diabetic control. Group III served as a treatment for phytoecdysteroids (10mg/kg), and group IV served as a treatment for phytoecdysteroids (20mg/kg). Phytoecdysteroids restored body weight loss to its antihyperglycemic effect. Blood glucose was reduced 19.2 and 52.9% in group III and IV respectively. Blood insulin (54.9 and 105.88%) and total protein (25 and 72.2%) was increased in group III and IV respectively. BUN, creatinine, TG, cholesterol and lipid peroxidation was significantly reduced following treatment. Catalase, superoxide dismutase (SOD), and glutathione peroxidase activity were significantly increased following treatment. Islet β-cells are lost in alloxan-induced diabetic rats. Regeneration of islets and reduced atrophy of acinar cells were noted. The number of insulin-secreting cells was tremendously reduced in alloxan-induced diabetic rats. Insulin-secreting cells were increased 48 and 61% in group III and IV respectively. Hexokinase-I mRNA (28.3 & 93.5%) and protein (27.9 and 55.3%) expression were significantly increased following treatment. Taking all these data together, it is suggested that the phytoecdysteroid could be a potential therapeutic agent against experimental diabetes.

A strategy for L-isoleucine dioxygenase screening and 4-hydroxyisoleucine production by resting cells

L-Isoleucine dioxygenase (IDO) specifically converts L-isoleucine(L-Ile) to 4-hydroxyisoleucine(4-HIL). To obtain IDO with improved activity, a strategy was developed that is dependent on the restoration of succinate-minus E. coli cell growth by the coupling of L-Ile hydroxylation and the oxidation of α-ketoglutarate(α-KGA) to succinate. Five mutants were obtained with this strategy, and the characteristics of IDO^M3, which exhibited the highest activity, were studied. The catalytic efficiency, thermal stability and catalytic rate of IDO^M3 were significantly improved compared with those of wild-type IDO. Moreover, an efficient method for the biotransformation of 4-HIL by resting cells expressing IDO^M3 was developed, with which 151.9 mmol of 4-HIL/L (22.4 g/L) was synthesized in 12 h while the substrates seldom exhibited additional consumption.

A small plant with big benefits: Fenugreek (Trigonella foenum-graecum Linn.) for disease prevention and health promotion

Plant-derived natural products have long-standing utility toward treating degenerative diseases. It is estimated that about two-thirds of world population depend on traditional medicine for primary medical needs. Fenugreek (Trigonella foenum-graecum Linn.), a short-living annual medicinal plant belonging to Fabaceae family, is used extensively in various parts of the world as herb, food, spice, and traditional medicine. Fenugreek is considered as one of the oldest medicinal plants and its health-promoting effects have been cited in Ayurveda and traditional Chinese medicine. The investigations into the chemical composition and pharmacological actions have seen a renaissance in recent years. Extensive preclinical and clinical research have outlined the pharmaceutical uses of fenugreek as antidiabetic, antihyperlipidemic, antiobesity, anticancer, anti-inflammatory, antioxidant, antifungal, antibacterial, galactogogue and for miscellaneous pharmacological effects, including improving women's health. The pharmacological actions of fenugreek are attributed to diverse array of phytoconstituents. The phytochemical analysis reveals the presence of steroids, alkaloids, saponins, polyphenols, flavonoids, lipids, carbohydrates, amino acids, and hydrocarbons. This review aims to summarize and critically analyze the current available literature to understand the potential of fenugreek for disease prevention and health improvement with special emphasis on cellular and molecular mechanisms. Current challenges and new directions of research on fenugreek are also discussed.

Beneficial effects of legumes on parameters of the metabolic syndrome: a systematic review of trials in animal models

Legume consumption plays a pivotal role in the prevention and treatment of the metabolic syndrome (MetS). This systematic review aimed to highlight the beneficial effects of legume interventions for the prevention and/or improvement of parameters related to the MetS and the implicated metabolic pathways so far reported. The methodology involved a search in four electronic databases (Medline, Web of Science, Scopus, Cochrane Library) from January 2007 to December 2014, considering as descriptors ‘Metabolic Syndrome’ and ‘Fabaceae’ and adequately adjusting the equation in each one of them. In total, forty-one studies were finally included. The majority of the studies described a regulating effect on glucose and lipid metabolism due to legume administration, whereas effects on blood pressure and renal parameters are not fully described. Regarding the metabolic pathways involved, they include the up-regulation of genes related to β-oxidation and acetyl-CoA degradation and the down-regulation of glycolytic and lipogenesis genes, as well as those associated with the acetyl-CoA synthesis. The ameliorating effects of legume consumption on the alterations associated with the MetS are clearly reported and coincide with changes in the expression of protein and genes involved in lipid and glucose metabolism. More research needs to be conducted including more legume species that are highly consumed as part of a healthy dietary pattern.

Antidiabetic and Antioxidant Impacts of Desert Date (Balanites aegyptiaca) and Parsley (Petroselinum sativum) Aqueous Extracts: Lessons from Experimental Rats

Medicinal plants are effective in controlling plasma glucose level with minimal side effects and are commonly used in developing countries as an alternative therapy for the treatment of type 1 diabetes mellitus. The aim of this study is to evaluate the potential antidiabetic and antioxidant impacts of Balanites aegyptiaca and Petroselinum sativum extracts on streptozotocin-induced diabetic and normal rats. The influences of these extracts on body weight, plasma glucose, insulin, total antioxidant capacity (TAC), malondialdehyde (MDA) levels, and liver-pyruvate kinase (L-PK) levels were assessed. Furthermore, the weight and histomorphological changes of the pancreas were studied in the different experimental groups. The herbal preparations significantly reduced the mean plasma glucose and MDA levels and significantly increased the mean plasma insulin, L-PK, and TAC levels in the treated diabetic groups compared to the diabetic control group. An obvious increase in the weight of the pancreas and the size of the islets of Langerhans and improvement in the histoarchitecture were evident in the treated groups compared to untreated ones. In conclusion, the present study provides a scientific evidence for the traditional use of these extracts as antidiabetic and antioxidant agents in type 1 diabetes mellitus.

Role of Fenugreek in the prevention of type 2 diabetes mellitus in prediabetes

Background

It is hypothesized that dietary supplementation with Fenugreek modulates glucose homeostasis and potentially prevents diabetes mellitus in people with prediabetes. The objective of present study is to determine whether Fenugreek can prevent the outcome of T2DM in non diabetic people with prediabetes.

Methods

A 3-year randomized, controlled, parallel study for efficacy of Fenugreek (n = 66) and matched controls (n = 74) was conducted in men and women aged 30–70 years with criteria of prediabetes. Fenugreek powder, 5 g twice a day before meals, was given to study subjects and progression of type 2 diabetes mellitus (T2DM) was monitored at baseline and every 3 months for the 3-year study.

Results

By the end of intervention period, cumulative incidence rate of diabetes reduced significantly in Fenugreek group when compared to controls. The Fenugreek group also saw a significant reduction in fasting plasma glucose (FPG), postprandial plasma glucose (PPPG) and low density lipoprotein cholesterol (LDLc) whereas serum insulin increased significantly. It was observed that controls had 4.2 times higher chance of developing diabetes compared to subjects in the Fenugreek group. The outcome of diabetes in Fenugreek group was positively associated with serum insulin and negatively associated with insulin resistance (HOMA IR).

Conclusions

Dietary supplementation of 10 g Fenugreek/day in prediabetes subjects was associated with lower conversion to diabetes with no adverse effects and beneficial possibly due to its decreased insulin resistance.

Leucaena leucocephala fruit aqueous extract stimulates adipogenesis, lipolysis, and glucose uptake in primary rat adipocytes

Leucaena leucocephala had been traditionally used to treat diabetes. The present study was designed to evaluate in vitro “insulin-like” activities of Leucaena leucocephala (Lam.) deWit. aqueous fruit extract on lipid and glucose metabolisms. The ability of the extract to stimulate adipogenesis, inhibit lipolysis, and activate radio-labeled glucose uptake was assessed using primary rat adipocytes. Quantitative Real-Time RT-PCR was performed to investigate effects of the extract on expression levels of genes (protein kinases B, AKT; glucose transporter 4, GLUT4; hormone sensitive lipase, HSL; phosphatidylinositol-3-kinases, PI3KA; sterol regulatory element binding factor 1, Srebp1) involved in insulin-induced signaling pathways. L. leucocephala aqueous fruit extract stimulated moderate adipogenesis and glucose uptake into adipocytes when compared to insulin. Generally, the extract exerted a considerable level of lipolytic effect at lower concentration but decreased gradually at higher concentration. The findings concurred with RT-PCR analysis. The expressions of GLUT4 and HSL genes were upregulated by twofold and onefold, respectively, whereas AKT, PI3KA, and Srebp1 genes were downregulated. The L. leucocephala aqueous fruit extract may be potentially used as an adjuvant in the treatment of Type 2 diabetes mellitus and weight management due to its enhanced glucose uptake and balanced adipogenesis and lipolysis properties.

4-Hydroxyisoleucine ameliorates fatty acid-induced insulin resistance and inflammatory response in skeletal muscle cells

The 4-hydroxyisoleucine (4-HIL), an unusual amino acid isolated from the seeds of Trigonella foenum-graecum was investigated for its metabolic effects to ameliorate free fatty acid-induced insulin resistance in skeletal muscle cells. An incubation of L6 myotubes with palmitate inhibited insulin stimulated-glucose uptake and -translocation of glucose transporter 4 (GLUT4) to the cell surface. Addition of 4-HIL strongly prevented this inhibition. We then examined the insulin signaling pathway, where 4-HIL effectively inhibited the ability of palmitate to reduce insulin-stimulated phosphorylation of insulin receptor substrate-1 (IRS-1), protein kinase B (PKB/AKT), AKT substrate of 160 kD (AS160) and glycogen synthase kinase 3β (GSK-3β) in L6 myotubes. Moreover, 4-HIL presented strong inhibition on palmitate-induced production of reactive oxygen species (ROS) and associated inflammation, as the activation of NF-κB, JNK1/2, ERK1/2 and p38 MAPK was greatly reduced. 4-HIL also inhibited inflammation-stimulated IRS-1 serine phosphorylation and restored insulin-stimulated IRS-1 tyrosine phosphorylation in the presence of palmitate, leading to enhanced insulin sensitivity. These findings suggested that 4-HIL could inhibit palmitate-induced, ROS-associated inflammation and restored insulin sensitivity through regulating IRS-1 function.

Phytotherapy in diabetes: Review on potential mechanistic perspectives

Diabetes mellitus (DM) is a widely spread epidemic disease that results from the absence of insulin, decreased secretion and/or impaired function. Since DM is a multi-factorial disease, the available pharmaceuticals, despite their sensible treatment, target mostly one pathway to control hyperglycemia and encounter several side effects. Therefore, new therapeutic paradigms aim to hit several pathways using only one agent. Traditionally, antidiabetic plants and/or their active constituents may fulfill this need. More than 200 species of plants possess antidiabetic properties which were evaluated mostly by screening tests without digging far for the exact mode of action. Searching among the different literature resources and various database and in view of the above aspects, the present article provides a comprehensive review on the available antidiabetic plants that have been approved by pharmacological and clinical evaluations, and which their mechanism(s) of action is assured. These plants are categorized according to their proved mode of action and are classified into those that act by inhibiting glucose absorption from intestine, increasing insulin secretion from the pancreas, inhibiting glucose production from hepatocytes, or enhancing glucose uptake by adipose and muscle tissues. The current review also highlights those that mimic in their action the new peptide analogs, such as exenatide, liraglutide and dipeptidylpeptidase-4 inhibitors that increase glucagon-like peptide-1 serum concentration and slow down the gastric emptying.

Fenugreek potent activity against nitrate-induced diabetes in young and adult male rats

Nitrate has described as an endocrine disruptor that promotes onset of diabetes. This study was undertaken to evaluate diabetic effect of high nitrate intake in young and adult male rats and its amelioration by fenugreek administration. The study revealed significant increase in serum glucose and blood glycosylated hemoglobin (HbA1c%), while serum insulin and liver glycogen were decreased among nitrate exposed animals, in particular the young group. A significant reduction in the body weight gain and serum thyroid hormones (T4 & T3) was also recorded. Further reduction in serum levels of urea and creatinine, as well as total protein in serum, liver and pancreas was demonstrated, with elevation in their levels in the urine of all nitrate exposed groups. Meanwhile, the activity of serum transaminases (ALT and AST) was increased, with decline in their activity in the liver tissue. In addition, an elevation in serum total bilirubin, tissues (liver and pancreas) nitric oxide and lipid profile, as well as liver activity of glucose-6-phosphatase was recorded. Fenugreek administration to nitrate exposed rats was found to be effective in alleviating hyperglycemia and other biochemical changes characterizing nitrate-induced diabetes. So, fenugreek can be considered to possess potent activity against onset of nitrate induced-diabetes.

Antihyperlipidemic effect of a polyherbal mixture in streptozotocin-induced diabetic rats

The effects of a polyherbal mixture containing Allium sativum, Cinnamomum zeylanicum, Citrullus colocynthis, Juglans regia, Nigella sativa, Olea europaea, Punica granatum, Salvia officinalis, Teucrium polium, Trigonella foenum, Urtica dioica, and Vaccinium arctostaphylos were tested on biochemical parameters in diabetic rats. The animals were randomized into three groups: (1) normal control, (2) diabetic control, and (3) diabetic rats which received diet containing 15% (w/w) of this mixture for 4 weeks. Diabetes was induced by intraperitoneal injection of streptozotocin (55 mg/kg). At the end of experiment, the mixture had no significant effect on serum hepatic enzymes, aspartate aminotransferase, and alanine aminotransferase activities. However, the level of fasting blood glucose, water intake, and urine output in treated group was lower than that in diabetic control rats (P < 0.01). Also, the levels of triglyceride and total cholesterol in polyherbal mixture treated rats were significantly lower than those in diabetic control group (P < 0.05). Our results demonstrated that this polyherbal mixture has beneficial effects on blood glucose and lipid profile and it has the potential to be used as a dietary supplement for the management of diabetes.

Fenugreek seeds, a hepatoprotector forage crop against chronic AlCl3 toxicity

Background

Having considered how bioavailable aluminium (Al) may affect ecological systems and animals living there, especially cattle, and in search for a preventive dietary treatment against Al toxicity, we aimed to test the protective role of fenugreek seeds against chronic liver injury induced by aluminum chloride (AlCl₃) in Wistar rats.

Results

Five months of AlCl₃ oral exposure (500 mg/kg bw i.g for one month then 1600 ppm via drinking water) caused liver atrophy, an inhibition of aspartate transaminase (AST), alanine transaminase (ALT) and glutamyl transpeptidase (GGT), an enhancement of both lipid peroxidation and lactate dehydrogenase (LDH) activity and an increase of total protein level in liver. Moreover, histopathological and histochemical examinations revealed moderate alterations in the hepatic parenchyma in addition to a disrupted iron metabolism. Co-administration of fenugreek seed powder (FSP) at 5% in pellet diet during two months succeeded to antagonize the harmful effects of AlCl₃ by restoring all tested parameters.

Conclusion

This study highlighted the hepatotoxicity of AlCl₃ through biochemical and histological parameters in one hand and the hepatoprotective role of fenugreek seeds on the other hand. Thus this work could be a pilot study which will encourage farmers to use fenugreek seeds as a detoxifying diet supplement for domestic animals.

The potential of fenugreek (Trigonella foenum-graecum) as a functional food and nutraceutical and its effects on glycemia and lipidemia

Dietary fiber from fenugreek blunts glucose and cholesterol after a meal and regulates the production of cholesterol in the liver. The mechanisms for these effects have not been fully elucidated. Fenugreek seeds contain 45.4% dietary fiber (32% insoluble and 13.3% soluble), and the gum is composed of galactose and mannose. The latter compounds are associated with reduced glycemia and cholesterolemia. Fenugreek's hypoglycemic effect has been especially documented in humans and animals with type 1 and type 2 diabetes mellitus. In addition, this dietary fiber has potential for widespread use in the food industry because its galactomannan composition has emulsifying and stabilizing properties. Flour supplemented with 8%-10% fenugreek dietary fiber has been used in the production of baked goods such as bread, pizza, muffins, and cakes. This application to flour allows for the production of functional foods that may be widely acceptable to consumers observing western diets.

Survey on medicinal plants and spices used in Beni-Sueif, Upper Egypt

BACKGROUND

This study was conducted to identify medicinal plants and spices used for medicine by the community of Beni-Sueif, Upper Egypt.

METHODS

Ethnobotanical data from local people was collected using direct interviews and a semi-structured questionnaire.

RESULTS

Forty-eight plant species belonging to twenty-seven families and forty-seven genera were encountered during the study. Their botanical and vernacular names, plant parts used and medicinal uses are given. Results of the study were analyzed using two quantitative tools. The factor informant consensus indicated the agreement in the use of plants and the fidelity level indicated the ratio between the number of informants who independently suggested the use of a species for the same major purpose and the total number of informants who mentioned the plant for any use. The results of the factor informant consensus showed that the cardiovascular category has the greatest agreement, followed by the immunological, gastrointestinal and respiratory categories. The most important species according to their fidelity are: Hibiscus sabdariffa L. for the cardiovascular category; Trigonella foenum-graecum L. for the immunological category; Mentha piperita L. for the gastrointestinal category and Pimpinella anisum L. for the respiratory category.

CONCLUSIONS

Medicinal plants are still used for treatment in Beni-Sueif community despite the availability of prescribed medications. Documentation of this ethnomedicinal knowledge is important. Evaluation of pharmacological activity for the promising medicinal plants is suggested.

Spices as functional foods

Spices and aromatic herbs have been used since antiquity as preservatives, colorants, and flavor enhancers. Spices, which have long been the basis of traditional medicine in many countries, have also been the subject of study, particularly by the chemical, pharmaceutical, and food industries, because of their potential use for improving health. Both in vitro and in vivo studies have demonstrated how these substances act as antioxidants, digestive stimulants, and hypolipidemics and show antibacterial, anti-inflammatory, antiviral, and anticancerigenic activities. These beneficial physiological effects may also have possible preventative applications in a variety of pathologies. The aim of this review is to present an overview of the potential of spices and aromatic herbs as functional foods.

Aqueous extract of Abutilon indicum Sweet inhibits glucose absorption and stimulates insulin secretion in rodents

The objective of this study was to evaluate the antidiabetic effects of the aqueous extract derived from the Thai Abutilon indicum Sweet plant and to explore its effects on intestinal glucose absorption and insulin secretion. The authors hypothesized that the plasma glucose level could be reduced through the inhibition of glucose absorption and/or the enhancement of insulin secretion. Administration of the extract (0.5 and 1 g/kg body weight) in an oral glucose tolerance test led to a significant reduction in plasma glucose levels in 30 minutes after the administration in moderately diabetic rats, as compared with untreated rats (P < .05), and this was at a faster rate than the use of an antidiabetic drug, glibenclamide. The inhibition of glucose absorption through the small intestine was investigated using an everted intestinal sac. The results showed that the extract at concentrations of 0.156 to 5 mg/mL caused a reduction of glucose absorption in a dose response manner. The maximum response was noted at a dose of 2.5 mg/mL. The promotion of the extract on insulin secretion was confirmed by incubating beta cell of pancreatic islets and INS-1E insulinoma cells with the extract at 1 to 1000 microg/mL. These observations suggest that the aqueous extract from the A indicum plant has antidiabetic properties, which inhibited glucose absorption and stimulated insulin secretion. Phytochemical screening also revealed that the extract contained alkaloids, flavonoids, tannins, glycosides, and saponins that could account for the observed pharmacologic effects of the plant extract.