Effect of fenugreek consumption on serum lipid profile: A systematic review and meta-analysis.

Various studies have shown that Trigonella foenum-graecum (fenugreek) supplementation has lipid-lowering activity. This meta-analysis was performed to evaluate the effect of fenugreek supplementation on human serum lipid profile. Data sources were PubMed, EMBASE, Scopus, and Coherence library which were searched systematically from January 2000 up to December 2019. Inclusion criteria were randomized clinical trial (RCT) study design, at least one of lipid profile components (triglyceride [TG], total cholesterol [TC], low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol) levels measured before fenugreek use and one of the lipid components level reported as result. The pooled weighted mean difference (MD) and its 95% confidence interval (CI) were calculated and pooled using a random-effect model. Only articles published in English were considered. Fifteen RCTs involving 281 cases consumed fenugreek and 255 control cases in controlled group (11 articles) and 136 cases in uncontrolled group (4 articles) were analyzed in our study. Pooled data of indicated a significant impact of fenugreek supplementation on lowering TC (-1.13 [-1.88, -0.37]; p = .003), low-density lipoprotein (LDL) (-1.26 [-2.09, -0.43]; p = .003), and TG (-1.07 [-1.82, -0.33]; p = 0.005) and increasing the high-density lipoprotein (HDL) level (0.70 [0.07, 1.34]; p = .03) compared with the control group. There were no significant differences in TC, TG, and LDL between pre- and post-fenugreek studies in the noncontrolled studies however, the result of combination of four studies without control group showed a significant increase in mean HDL (0.81 [0.33,1.29]; p-value = .001). The results of subgroup analysis showed that the fenugreek reduced the TG and LDL and increases HDL levels in diabetic subjects more effectively. Fenugreek supplementation significantly improved lipid profile (LDL, TG, TC, and HDL). It could be considered as an effective lipid-lowering medicinal plant. Further high-quality studies are needed to firmly establish the clinical efficacy of the plant.

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.

Hydrolytic enzymes mediated lipid-DNA catabolism and altered gene expression of antioxidants under combined application of lead and simulated acid rain in Fenugreek (Trigonella foenum graecum L.) seedlings.

Understanding ill effects of simultaneous existence of various abiotic stresses, commonly observed due to various anthropogenic activities and global climate change these days, over plants growth, metabolic activity and yield responses are important for continued agricultural productivity and food security. In the present study, seedlings of Fenugreek (Trigonella foenum graecum L.) were subjected to lead (Pb, 1200 ppm) and/or simulated acid rain (SAR, pH 3.5) for 30 days, and were then analysed. The results revealed reduced growth, and total lipid and DNA contents, while enhanced Pb accumulation, biological concentration factor, biological accumulation coefficient, translocation factor, lipase activity, and levels of free fatty acid, conjugated diene, lipid hydroperoxide, DNA oxidation and DNase activity under Pb and/or SAR exposure. Additionally, activities and gene expression levels of antioxidants (superoxide dismutase, catalase, guaiacol peroxidase and ascorbate peroxidase) were enhanced in response to applied treatments. The results also suggested that inhibitions/ accelerations determined under joint addition of Pb and SAR were comparatively more profound than those measured under their single application. Additionally, root was more sensitive to Pb treatment, compared to both leaf and shoot. Hence, under simultaneous presence of two or more number of abiotic stresses, the strategy opted by plants for survival is chiefly governed by the interaction between prevailing stressors, which is then conceived by plants as a new state of stress.

Role of bulk and Nanosized SiO2 to overcome salt stress during Fenugreek germination (Trigonella foenum- graceum L.).

The effects of bulk and Nanosized SiO2 on seed germination and seedling growth indices of fenugreek under salinity stress were studied in the College of Agriculture, Ferdowsi University of Mashhad, Iran, in 2013. The experimental treatments included 4 levels of salinity stress (0, 50, 100 and 150 mM), 2 concentrations of bulk (50 and 100 ppm), 2 concentrations of nanosized SiO2 (50 and 100 ppm), and control (without any SiO2 types). Seedling growth attributes significantly improved when bulk and nanosized SiO2 concentrations applied singly or with different levels of salt stress. However, they significantly declined with salt application. The adverse effects of salt on shoot, root and seedling lengths were alleviated by application of 50 ppm nanosized SiO2 treatment. Under salt stress condition, addition of 50 and 100 ppm nanosized SiO2 to fenugreek seeds increased shoot, root and seedling dry weights as compared to bulk SiO2 concentrations and control treatments, though 50 ppm nanosized SiO2 was more effective than 100 ppm nanosized SiO2 application. It was concluded that nanosized SiO2 improves growth attributes of fenugreek and mitigate adverse effects of salt stress.

Biogeography of a Novel Ensifer meliloti Clade Associated with the Australian Legume Trigonella suavissima.

Here, we describe a novel clade within Ensifer meliloti and consider how geographic and ecological isolation contributed to the limited distribution of this group. Members of the genus Ensifer are best known for their ability to form nitrogen-fixing symbioses with forage legumes of three related genera, Medicago L., Melilotus Mill., and Trigonella L., which are members of the tribe Trifolieae. These legumes have a natural distribution extending from the Mediterranean Basin through western Asia, where there is an unsurpassed number of species belonging to these genera. Trigonella suavissima L. is unusual in that it is the only species in the tribe Trifolieae that is native to Australia. We compared the genetic diversity and taxonomic placement of rhizobia nodulating T. suavissima with those of members of an Ensifer reference collection. Our goal was to determine if the T. suavissima rhizobial strains, like their plant host, are naturally limited to the Australian continent. We used multilocus sequence analysis to estimate the genetic relatedness of 56 T. suavissima symbionts to 28 Ensifer reference strains. Sequence data were partitioned according to the replicons in which the loci are located. The results were used to construct replicon-specific phylogenetic trees. In both the chromosomal and chromid trees, the Australian strains formed a distinct clade within E. meliloti The strains also shared few alleles with Ensifer reference strains from other continents. Carbon source utilization assays revealed that the strains are also unusual in their ability to utilize 2-oxoglutarate as a sole carbon source. A strategy was outlined for locating similar strains elsewhere.IMPORTANCE In this study, we employed a biogeographical approach to investigate the origins of a symbiotic relationship between an Australian legume and its nitrogen-fixing rhizobia. The question of the ancestral origins of these symbionts is based on the observation that the legume host is not closely related to other native Australian legumes. Previous research has shown that the legume host Trigonella suavissima is instead closely related to legumes native to the Mediterranean Basin and western Asia, suggesting that it may have been introduced in Australia from those regions. This led to the question of whether its rhizobia may have been introduced as well. In this study, we were unable to find persuasive evidence supporting this hypothesis. Instead, our results suggest either that the T. suavissima rhizobia are native to Australia or that our methods for locating their close relatives elsewhere are inadequate. A strategy to investigate the latter alternative is proposed.

Physiological responses of fenugreek seedlings and plants treated with cadmium.

The bioaccumulation efficiency of cadmium (Cd) by fenugreek (Trigonella foenum-graecum) was examined using different concentrations of CdCl2. The germination rate was similar to control except at 10 mM Cd. However, early seedling growth was quite sensitive to the metal from the lowest Cd level. Accordingly, amylase activity was reduced substantially on treatment of seeds with 0.5, 1, and 10 mM Cd. Cadmium also affected various other plant growth parameters. Its accumulation was markedly lower in shoots as compared to roots, reducing root biomass by almost 50 %. Plants treated with 1 and 5 mM Cd presented chlorosis due to a significant reduction in chlorophyll b especially. Furthermore, at Cd concentrations greater than 0.1 mM, plants showed several signs of oxidative stress; an enhancement in root hydrogen peroxide (H2O2) level and in shoot malondialdehyde (MDA) content was observed. Conversely, antioxidant enzyme activities (superoxide dismutase (SOD), ascorbate peroxidase (APX), and catalase (CAT)) increased in various plant parts. Likewise, total phenolic and flavonoid contents reached their highest values in the 0.5 mM Cd treatment, consistent with their roles in quenching low concentrations of reactive oxygen species (ROS). Consequently, maintaining oxidant and antioxidant balance may permit fenugreek to hyperaccumulate Cd and allow it to be employed in extremely Cd polluted soils for detoxification purposes.

Mannitol-induced drought stress on calli of Trigonellafoenum-graecum L. Var. RMt-303.

Different explants of fenugreek, T. foenum-graecum L. (Var. RMt-303), were compared for their callus induction and subsequent shoot regeneration capabilities on Murashige and Skoog media supplemented with different phytohormones in varying concentration. The highest percentage of callus induction frequency was observed in 1 ppm benzylaminopurine (BAP). Maximum shoots were induced on media supplemented with 0.5 ppm BAP using leaf and stem tissues as explants. However, root tissues showed only callusing with no subsequent shooting. Cotyledonary node responded better than hypocotyls in terms of shoot induction on media supplemented with thidiazuron (0.1 ppm). The callus was subjected to drought stress as simulated by reduced water potential of growth media due to addition of mannitol. Calli could withstand -2 MPa water potential till 30 days indicating that the drought stress tolerance mechanisms are functional in this variety. Chlorophyll a and b and total chlorophyll, proline and total phenolic contents, total peroxidase and catalase activities increased under stress conditions suggesting the tolerance of callus to drought stress. However, ascorbate peroxidase, guaiacol peroxidase activities were found to decrease slightly. Malondialdehyde and H2O2 contents were found to decrease while only a slight disturbance was found in membrane stability index. These results underline the mechanisms that are crucial for drought stress tolerance in fenugreek.

Activation of Rhizobium tibeticum with flavonoids enhances nodulation, nitrogen fixation, and growth of fenugreek (Trigonella foenum-graecum L.) grown in cobalt-polluted soil.

The goal of this study was to investigate the response of activation of Rhizobium tibeticum with mixture of hesperetin and apigenin to improve growth, nodulation, and nitrogen fixation of fenugreek grown under cobalt (Co) stress. The current study showed that high concentrations of Co-induced noxious effects on rhizobial growth, nod gene expression, nodulation, phenylalanine ammonia-lyase (PAL) and glutamine synthetase (GS) activities, total flavonoid content, and nitrogen fixation. Addition of a mixture of hesperetin and apigenin to growth medium supplemented with different concentrations of Co significantly increased bacterial growth. PAL activity of roots grown hydroponically at 100 mg kg(-1) Co and inoculated with induced R. tibeticum was significantly increased compared with plants receiving uninduced R. tibeticum. Total flavonoid content of root exudates of plants inoculated with activated R. tibeticum was significantly increased compared with inoculated plants with unactivated R. tibeticum or uninoculated plants at variant Co dosages. Application of 50 mg kg(-1) Co significantly increased nodulation, GS, nitrogenase activity, and biomass of plants inoculated with either or uninduced R. tibeticum. The total number and fresh mass of nodules, nitrogenase activity, and biomass of plants inoculated with induced cells grown in soil treated with 100 and 200 mg kg(-1) Co were significantly increased compared with plants inoculated with uninduced cells. Induced R. tibeticum with flavonoids significantly alleviates the adverse effect of Co on nod gene expression and therefore enhances nitrogen fixation. Induction of R. tibeticum with compatible flavonoids could be of practical importance in augmenting growth and nitrogen fixation of fenugreek grown in a Co-contaminated agroecosystem.

Arbuscular mycorrhizal symbiosis modulates antioxidant response in salt-stressed Trigonella foenum-graecum plants.

An experiment was conducted to evaluate the influence of Glomus intraradices colonization on the activity of antioxidant enzymes [superoxide dismutase (SOD), catalase (CAT), peroxidase (PX), ascorbate peroxidase (APX), and glutathione reductase (GR)] and the accumulation of nonenzymatic antioxidants (ascorbic acid, α-tocopherol, glutathione, and carotenoids) in roots and leaves of fenugreek plants subjected to varying degrees of salinity (0, 50, 100, and 200 mM NaCl) at two time intervals (1 and 14 days after saline treatment, DAT). The antioxidative capacity was correlated with oxidative damage in the same tissue. Under salt stress, lipid peroxidation and H2O2 concentration increased with increasing severity and duration of salt stress (DoS). However, the extent of oxidative damage in mycorrhizal plants was less compared to nonmycorrhizal plants. The study reveals that mycorrhiza-mediated attenuation of oxidative stress in fenugreek plants is due to enhanced activity of antioxidant enzymes and higher concentrations of antioxidant molecules. However, the significant effect of G. intraradices colonization on individual antioxidant molecules and enzymes varied with plant tissue, salinity level, and DoS. The significant effect of G. intraradices colonization on antioxidative enzymes was more evident at 1DAT in both leaves and roots, while the concentrations of antioxidant molecules were significantly influenced at 14DAT. It is proposed that AM symbiosis can improve antioxidative defense systems of plants through higher SOD activity in M plants, facilitating rapid dismutation of O2 (-) to H2O2, and subsequent prevention of H2O2 build-up by higher activities of CAT, APX, and PX. The potential of G. intraradices to ameliorate oxidative stress generated in fenugreek plants by salinity was more evident at higher intensities of salt stress.

The effect of galactagogue herbal tea on oxidant and anti-oxidant status of human milk.

OBJECTIVE: Human milk (HM) has antioxidant constituents which protect newborns against oxidative damage. We aimed to evaluate whether maternal consumption of herbal tea containing fenugreek had any effects on global oxidant and antioxidant capacity of HM. METHODS: Volunteer mothers 18-35 years of age without any antenatal or perinatal risk factors were randomly assigned to receive galactagogue herbal tea (Humana still-tee®, Herford, Deutschland) 3 cups/d or same amount of water as placebo. The total antioxidant capacity (TAC), total oxidant status (TOS) and the oxidative stress index (OSI) of breast milk samples taken in the 1st day and 7-10 d were compared between groups. RESULTS: Herbal tea (n = 40) and placebo (n = 40) groups had similar TAC, TOS and OSI values in the 1st day samples. TAC, TOS and OSI values in the breast milk samples taken on 7-10th day were also similar. OSI increased significantly in 7-10 day samples compared to 1st day in each group, while TAC and TOS levels did not differ. CONCLUSION: Galactagogue herbal tea containing fenugreek has no detectable effect on global oxidant and antioxidant status of HM. OSI increases in course of lactation compared to colostrums irrespective of galactagogue use.

Ultrastructural evidence for AMF mediated salt stress mitigation in Trigonella foenum-graecum.

The study unveils that inoculation with arbuscular mycorrhizal fungus (Glomus intraradices Schenck and Smith) prevents salt-induced ultrastructural alterations in fenugreek (Trigonella foenum-graecum L.) plants. Mycorrhizal (M) and non-mycorrhizal (NM) fenugreek plants were subjected to four levels of NaCl (0, 50, 100, and 200 mM NaCl). Salt-induced ultrastructural changes were captured using a Transmission Electron Microscope. Effects of salt on the ultrastructure of cells include shrinkage of protoplasm, widening apoplastic space between cell wall and cell membrane, disorganization of grana in chloroplast--swelling and reduction in the number of thylakoids, disintegration of chloroplast membrane, accumulation of plastoglobules, dilation of cristae and denser matrix in mitochondria, and aggregation of chromatin in nucleus. However, the extent of salt-induced ultrastructural damage was less in M plants as compared to NM plants. Lower lipid peroxidation and electrolyte leakage in M plants also indicated less membrane damage. This reduction of ultrastructure damage is a demonstration of enhanced tolerance in M plants to salt stress. The AMF-mediated lesser damage may be due to higher osmolyte (glycinebetaine, sugars) and polyamines concentration, and more and bigger plastoglobules (higher α-tocopherol concentration) in M plants as compared to NM plants. While lower Na(+) and Cl(-) ions assures less ionic toxicity, higher osmolytes and tocopherols ensure osmotic adjustment and better capacity to scavenge free radicals generated due to salt stress, respectively.

Enhancement of root growth and nitrogen fixation in Trigonella by UV-exclusion from solar radiation.

A field experiment was conducted to study the impact of solar UV on root growth and nitrogen fixation in Trigonella foenum-graecum. Plants were grown in iron mesh cages covered with polyester filters that could specifically cut off UV-B (280-315 nm) or UV-A + B (280-400 nm) part of the solar spectrum. The control plants were grown under a polythene filter transmissible to UV. Root biomass, number of nodules and nodule fresh weight were enhanced after exclusion of solar UV. Nitrogenase activity was significantly enhanced by 120% and 80% in the UV-B and UV-A + B excluded plants respectively. Along with nitrogenase there was concomitant increase in leghemoglobin and hemechrome content in the nodules after exclusion of solar UV. These components of sunlight limits nitrogen fixation and their elimination can enhance nitrogen fixation with agricultural advantages like reduction in the use of fertilizers.

Rhizobium tibeticum sp. nov., a symbiotic bacterium isolated from Trigonella archiducis-nicolai (Sirj.) Vassilcz.

Isolated from root nodules of Trigonella archiducis-nicolai (Sirj.) Vassilcz. grown in Tibet, China, cells of the bacterial strains CCBAU 85039(T) and CCBAU 85027 were Gram-negative, aerobic, motile, non-spore-forming rods that formed colonies that were semi-translucent and opalescent on yeast extract-mannitol agar. In numerical taxonomy, SDS-PAGE analysis of whole-cell proteins and DNA-DNA hybridization, the two strains were very similar and were different from reference strains of defined Rhizobium species. In the phylogeny based on 16S rRNA gene sequences, they were most similar to Rhizobium etli CFN 42(T) (98.2 % similarity) and R. leguminosarum USDA 2370(T) (97.6 %). Sequence analyses of the housekeeping genes recA, atpD and glnII and the 16S-23S rRNA intergenic spacer, phenotypic characteristics and cellular fatty acid profiles strongly suggested that these two strains represented a novel species within Rhizobium. Cross-nodulation tests and sequencing of nifH and nodA genes showed that these two strains were symbiotic bacteria that nodulated Trigonella archiducis-nicolai, Medicago lupulina, Medicago sativa, Melilotus officinalis, Phaseolus vulgaris and Trigonella foenum-graecum. Based on the results, the novel species Rhizobium tibeticum sp. nov. is described to accommodate the two strains. The type strain is CCBAU 85039(T) (=LMG 24453(T) =CGMCC 1.7071(T)). The DNA G+C content of this strain is 59.7 mol% (T(m)).

Efficacy of Trigonella foenum-graecum on third stage larvae and adult fecundity of Anopheles pharoensis.

The insecticidal activity of Trigonella foenum-graecunm (fenugreek) against the larval maturation and adult emergency of An. pharoensis 3rd stage was evaluated under controlled laboratory conditions. Concentrations of 100%, 70%, 50%, 25%, 5%, 2%, 1%, 0.9%, 0.7%, 0.5% & 0.3% showed 100% larval mortality rate. 0.2% & 0.1% caused mortality of 88.9% & 66.7% respectively. On the other hand, the fecundity of emerged adults was zero % and 33.3%. However, one control larvae died and the nine emerged adults were fertile. So, it was recommended to be use in controlling larvae of An. pharoensis.

Cloning, characterization and antifungal activity of defensin Tfgd1 from Trigonella foenum-graecum L.

Defensins are small cysteine rich peptides with a molecular mass of 5-10 kDa and some of them exhibit potent antifungal activity. We have cloned the coding region of a cDNA of 225 bp cysteine rich defensin, named as Tfgd1, from the legume Trigonella foenum-graecum. The amino acid sequence deduced from the coding region comprised 74 amino acids, of which the N-terminal 27 amino acids constituted the signal peptide and the mature peptide comprised 47 amino acids. The protein is characterized by the presence of eight cysteine resisdues, conserved in the various plant defensins forming four disulphide bridges, which stabilize the mature peptide. The recombinant protein expressed in E coli exhibited antifungal activity against the broad host range fungus, Rhizoctonia solani and the peanut leaf spot fungus, Phaeoisariopsis personata.

Breeding system in a population of Trigonella balansae (Leguminosae).

BACKGROUND AND AIMS: Although some taxonomic studies in the genus Trigonella have been conducted, there has been no concerted effort to study the breeding system. This paper examines the floral structure and pollination system in a population of T. balansae, an annual pasture legume. METHODS: Floral morphology, hand and vector pollination, stigma receptivity, pollen tube growth, using scanning electron and fluorescence microscopy, were conducted. KEY RESULTS: Measurements of floral structure from before to after anthesis indicates an inability for T. balansae to self-pollinate and a requirement for an external vector to effectively transfer pollen from the anthers onto the stigmas of this species. Seed set can be obtained by hand or honeybee manipulation of T. balansae flowers. CONCLUSIONS: Trigonella balansae is a self-compatible species, but which requires vectors such as honeybees to bring about pollination.