Trigonelline Research Articles

Identification of a novel phytoestrogen in coffee beans

Trigonelline (TRG), a niacin related compound, is a natural constituent of coffee accounting for approximately 1% dry matter in roasted beans. Studies exploring the effects of this bioactive compound on mammalian cells are limited. However, treatment of neuroblastoma cells with TRG resulted in increased formation of neurites and TRG inhibits invasion of hepatoma cells. The purpose of these studies was to determine if TRG also has endocrine actions in mammalian cells. Specifically, we sought to determine if TRG exhibits estrogenic properties by activating the estrogen receptor (ER). Proliferation of ER‐dependent breast cancer (MCF‐7) cells was used to screen for potential estrogenic actions of the compound. TRG stimulated MCF‐7 cell proliferation in a dose responsive manner and significantly enhanced cell growth at concentrations as low as 100pM. Co‐treatment of MCF‐7 cells with TRG and ICI, an ER antagonist, inhibited TRG induced cell proliferation. In addition, when cells were co‐treated with suboptimal doses of estradiol and TRG, an additive enhancement of MCF‐7 growth was observed. Estrogen response element (ERE)‐reporter assays and modulation of ER target genes (pS2, progesterone receptor, and cyclin D1) were also analyzed. These data demonstrate that TRG at low concentrations stimulates MCF‐7 cell growth and that this effect is mediated through ER. Thus, we have identified TRG as a novel phytoestrogen.

Neuropharmacological Activity of Trigonella foenum graecum Linn. Seeds

Objective: To evaluate the neuropharmacological activity of Trigonella foenum graecum (Fenugreek) seeds. Methods: Total alcoholic extract (TA), Total aqueous extract (TQ), Petroleum ether extract (PE), Total alkaloidal extract (TK), Total glycosidal extract (TG), Fenugreek oil (FO), Diosgenin (DI) and Trigonelline (TR) were assessed for their neuropharmacological activity in primary screening studies, locomotor activity and phenobarbitone induced sleeping time using albino Wistar rats. The extracts TA, TQ, PE and FO were administered 100 mg/kg b.w. and TK, TG, DI and TR were administered 50 mg/kg b.w. intraperitoneally. Caffeine (CF) (48 mg/kg) and Chlorpromazine hydrochloride (CP) (150 μg/kg) were used as standard drugs. Results: In all the studies, all the extracts and active principles except TQ showed significant central nervous system (CNS) stimulant activity, while TQ alone showed significant CNS depressant activity. Conclusion: Thus from the above studies, the active compounds present in the fenugreek seed extracts possess CNS stimulant and depressant activities.

Purification and Characterization of S-Adenosyl-L-Methionine Nicotinic Acid-N-Methyltransferase from Leaves of Glycine max

Trigonelline (TRG), which act as a cell cycle regulator and a compatible solute in response to salinity and water-stress, is the N-methyl conjugate of nicotinic acid the formation of which is catalyzed by S-adenosyl-L-methionine nicotinic acid-N-methyltransferase. The enzyme was purified 2650-fold from soybean (Glycine max L.) leaves with a recovery of 4 %. The purification procedure included ammonium sulfate (45 – 60 %) precipitation, linear gradient DEAE-Sepharose chromatography, adenosine-agarose affinity chromatography, hydroxyapatite chromatography and gel filtration (Sephacryl-S-200). The purified enzyme preparation showed a major band with a molecular mass of 41.5 kDa in sodium dodecyl sulfate-polyacrylamide gel electrophoresis that is related to the enzyme activity. The native enzyme had a molecular mass of about 85 kDa as estimated by gel filtration. The Km values for S-adenosyl-L-methionine and nicotinic acid were 31 and 12.5 μM, respectively. The purified enzyme showed optimum activity at pH 6.5 and temperature of 40 – 45 °C. High concentration of dithiothreitol (10 mM) and glycerol (20 %) stabilize the enzyme during purification and storage. Hg2+ strongly inhibits enzyme activity.

Trigonelline Concentration in Field-Grown Soybean in Response to Irrigation

Trigonelline (TRG) is a conjugate of nicotinic acid, and is postulated to function as a compatible solute in response to salinity- and water deficit-stresses. TRG concentrations and several agronomic characteristics were measured under irrigated field and non-irrigated field conditions within 18 soybean (Glycine max) genotypes using leaves taken from different growth stages (vegetative, flowering and pod development). Under irrigation, relative water content (RWC) ranged from 90.0 to 99.6 %. Under non-irrigation, RWC ranged from 86.3 to 97.5 %. TRG concentration ranged from 364 to 555 μg g−1(d.m.) under irrigation, and from 404 to 570 μg g−1(d.m.) under non-irrigation. TRG concentrations increased in the majority of genotypes (15 of 18) under non-irrigation even though RWC did not significantly differ in many genotypes between treatments. TRG decreased as plants progressed to pod development and seed filling. Mean seed yield under non-irrigated conditions declined 55 % relative to the irrigated controls. TRG concentrations among all genotypes were significantly correlated with seed yield.

Utility of Trigonelline as a Biochemical Market for Interspecific Competition between Soybean and the Weed Common Waterhemp

Interspecific competition between four soybean cultivars (PI471938, Stressland, Essex and Forrest) and the weed, common waterhemp was investigated under increasing weed densities (i.e. 0, 1, 4 and 16 plants per pot). Soybean height and leaflet number were measured over a 45-d period and used to calculate relative growth rates (RGR). Trigonelline (TRG) concentration was determined within the V1 leaf of 45-d-old soybean plants. Soybean leaflet number (P[lt ]0.05), soybean height (P[lt ]0.05) and soybean RGRh (expressed in terms of height) differed significantly (P[lt ]0.05) according to waterhemp density. At each waterhemp density Stressland matured at a significantly faster rate whereas the maturation rate of Essex decreased in the presence of waterhemp. Final TRG concentrations were affected by the interaction between soybean cultivar and waterhemp density. Under no competition, TRG concentration was significantly lower in Forrest relative to PI471938, Stressland and Essex. TRG concentrations in Essex declined in higher waterhemp densities.

Inactivation of DNA replication origins by the cell cycle regulator, trigonelline, in root meristems of Lactuca sativa.

The effects of trigonelline (TRG) on the cell cycle in root meristems of Lactuca sativa L. were examined in the knowledge that TRG is a cell cycle regulator that causes cell arrest in G2, and prevents ligation of replicons in S-phase. The hypothesis was tested that continuous exposure to TRG would perturb DNA replication which, in turn, would lengthen the cell cycle and impair root elongation. Using DNA fibre autoradiography, mean replicon size was 31 and 13 microm in the TRG (3 mM) and control treatments, respectively. Trigonelline also resulted in a lengthening of both S-phase and the cell cycle and a decrease in primary root elongation. Hence, replicon inactivation was responsible for the protracted S-phase. Trigonelline treatment also resulted in a 1.6-fold increase in fork rate (13.8 microm h(-1)) compared with the control (8.4 m h(-1)). The faster fork rate in the larger replicons is in accord with the highly significant positive relationship already established between fork rate and replicon size for various unrelated higher plants.

Quantitative Trait Loci Associated with Foliar Trigonelline Accumulation in Glycine Max L.

The objective of this study was to utilize a Glycine max RIL population to (1) evaluate foliar trigonelline (TRG) content in field-grown soybean, (2) determine the heritability of TRG accumulation, and (3) identify DNA markers linked to quantitative trait loci (QTLs) conditioning variation in TRG accumulation. Frequency distributions of 70 recombinant inbred lines showed statistically no significant departure from normality (P > .05) for TRG accumulation measured at pod development stage (R4). Six different molecular linkage groups (LGs) (B2, C2, D2, G, J, and K) were identified to be linked to QTLs for foliar TRG accumulation. Two unique microsatellite markers (SSR) on two different linkage groups identified QTL significantly associated with foliar TRG accumulation: a region on LG J (Satt285) (P = .0019, R2 = 15.9%) and a second region on LG C2 (Satt079) (P = .0029, R2 = 13.4%).

Comparison of Salt-Induced Osmotic Adjustment and Trigonelline Accumulation in Two Soybean Cultivars

21-d-old seedlings of the soybean (Glycine max) cvs. Essex and Forrest were treated with NaCl in a step-wise manner over 9 d (3 d 30 mM, 3 d 70 mM, and 3 d 100 mM) and maintained under 100 mM NaCl for an additional 14 d. During salt treatment, osmotic potential decreased more in cv. Forrest relative to cv. Essex. In non-stressed leaf tissue, cv. Forrest contained more trigonelline (TRG) relative to cv. Essex. During salt treatment, TRG amounts increased in cv. Forrest but were unchanged in cv. Essex. Both cvs. osmotically adjusted in response to salt stress; the maximal osmotic adjustment was 0.80 and 0.18 MPa in cv. Forrest and cv. Essex, respectively.

Facile, One-Step Preparation of Trigonellinate Esters

Abstract Trigonelline anhydride was synthesized and was found to readily react with various alcohols to yield the corresponding trigonellinate esters.

A survey of trigonelline concentrations in dry seeds of the dicotyledoneae

Ungerminated seeds of representatives of 21 of 24 superorders of the Dicotyledoneae were examined by high-pressure liquid chromatography for amounts of trigonelline (TRG), to determine if phylogenetic relationships are reflected in the relative amounts of TRG. With the exception of the Fabiflorae, the levels of TRG were quite variable within several superorders, whereas other superorders such as the Violiflorae, Primuliflorae, Rosiflorae, Rutiflorae, Araliiflorae and Gentianiflorae showed values that were consistently low. Overall, the amount of TRG present was relatively low in all of the superorders when compared with the relatively high TRG values of the Fabiflorae, the legumes. Many legumes have been shown to respond to TRG by predominant cell arrest in G2 and these possessed high concentrations of TRG. However, there are many non-legume nitrogen fixors, as well as several legumes that do not have significant TRG concentrations. From the above it appears that the concentrations of TRG in dry seeds are not well correlated with nitrogen fixation.