Search

The lignin from tritordeum straw, a hybrid cereal from crossbreeding of durum wheat and wild barley, was isolated and chemically characterized. Its composition and structure were studied by analytical pyrolysis (Py-GC/MS), nuclear magnetic resonance spectroscopy (NMR), Derivatization Followed by Reductive Cleavage (DFRC) method, and gel permeation chromatography (GPC). The data revealed an enrichment of guaiacyl (G) units (H:G:S of 3:61:36), which had a significant impact on the distribution of inter-unit linkages. The predominant linkages were the β– O –4′ alkyl-aryl ethers (78 % of all linkages), with substantial proportions of condensed linkages such as phenylcoumarans (11 %), resinols (4 %), spirodienones (4 %), and dibenzodioxocins (2 %). Moreover, DFRC revealed that tridordeum straw lignin was partly acylated at the γ-OH with both acetates and p -coumarates. Acetates were principally attached to G-units, whereas p -coumarates were predominantly attached to S-units. Furthermore, and more importantly, tritordeum lignin incorporates remarkable amounts of a valuable flavone, tricin, exceeding 30 g per kilogram of straw. Given the diverse industrial applications associated with this high-value molecule, tritordeum straw emerges as a promising and sustainable resource for its extraction. Synopsis: Tritordeum straw lignin is highly enriched in tricin incorporated into its structure. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Brown rice comprises a nutritious rice bran layer which contain phytochemicals. • These phytochemicals are attributed with potential clinical health benefits. • White rice being processed and polished is devoid of these bioactive compounds. • Nutrigenomic status of white rice may improve by incorporating brown rice traits. Whole-grain cereals are important components of a healthy diet. It reduces the risk of many deadly diseases like cardiovascular diseases, diabetes, cancer, etc. Brown rice is an example of whole grain food, which is highly nutritious due to the presence of various bioactive compounds (flavonoids, phenolics, vitamins, phytosterols, oils, etc.) associated with the rice bran layer of brown rice. White rice is devoid of the nutritious rice bran layer and thus lacks the bioactive compounds which are the major attractants of brown rice. Therefore, to confer health benefits to the public at large, the nutrigenomic potential of white rice may be improved by integrating the phytochemicals associated with the rice bran layer of brown rice into it via biofortification processes like conventional breeding, agronomic practices, metabolic engineering, CRISPR/Cas9 technology, and RNAi techniques. Thus, this review article focuses on improving the nutritional qualities of white/polished rice through biofortification processes, utilizing new breeding technologies (NBTs). [ABSTRACT FROM AUTHOR]

The differences in the composition and structure of the lignins from straws of different oat (Avena sativa L.) varieties, planted in two seasons (winter and spring), were studied in detail by different analytical techniques such as pyrolysis coupled to gas chromatography–mass spectrometry (Py-GC/MS), two-dimensional nuclear magnetic resonance (2D-NMR), derivatization followed by reductive cleavage (DFRC), and gel permeation chromatography (GPC). Overall, the analyses revealed that oat straw lignins were enriched in guaiacyl (G; 50–56 %) and syringyl (S; 39–44 %) units, with relatively lower amounts of p -hydroxyphenyl (H; 4–6 %) units. The lignins also incorporated significant quantities of p -coumarates (8–14 % of total lignin units), which are acylating the γ-OH of the lignin side chains, and predominantly over the S units. Furthermore, oat straw lignins also incorporated considerable amounts of the flavone tricin (5–12 % of total lignin units). Interestingly, this study revealed that the lignin content and composition of the oat straws vary with genotype and planting season. Since p -coumarates and tricin are high-value aromatic compounds especially attractive from a biorefinery point of view, the information disclosed here is highly relevant to plant breeding programs aimed at developing functional foods and lignin modifications for improved biorefinery applications. [Display omitted] [ABSTRACT FROM AUTHOR]

Highlights • The structural changes of carbohydrates and lignin caused by MW torrefaction were investigated. • The MW torrefaction resulted in the increasing yield of hydrophilic extractable materials with high antioxidant activity from aspen wood. • In wheat straw hydrophilic extracts a flavonoid monomer tricin and its derivatives have been found. • Due to tricins high antioxidant and cancer preventive activity and low toxicity, are considered as potential added value of wheat straw products. Abstract A comparative study of the modification of chemical structure of wheat straw and aspen wood initiated by microwave (MW) assisted torrefaction at different temperatures (150–300 °C) was carried out using Py-GC/MS-FID, FTIR, GC-FID and wet chemistry procedures as the main analytical tools. Differences in wood and wheat straw thermal transformations in the course of MW assisted torrefaction were revealed. Formation of extractable chemicals as the result of biomasses torrefaction was established. The most significant increase in formation of hydrophilic extractable chemicals was found for the both biomasses after torrefaction in the range of 250–280 °C. Antioxidant activity of extracts was assessed by the test with a free radical DPPH. The UPLC-ESI–MS/MS analysis of extracts from the both torrefied biomasses showed the presence of lignin-carbohydrate complex fragments. It was detected that a flavonoid monomer tricin and its derivatives were the dominant compounds in hydrophilic extracts from wheat straw. The results of the study provide useful information for valorization of potentially valuable lignocellulosic destruction products, which can be extracted from torrefied wood and cereal biomass. [ABSTRACT FROM AUTHOR]

Mesenchymal stem cells (MSCs) are multipotent stromal cells that are capable of differentiate into multilineage cell types including bone in vitro and in vivo . Aim of the study: They have been widely developed as a therapeutic approach for bone tissue repair and regeneration. However, the efficiency of lineage specific differentiation still needs improvement. We investigated the effect of Tricin on the proliferation of human adult MSCs by alamar blue assay, the mineralization of MSCs by staining of calcium deposition, and the expression levels of the osteoblastic marker genes during osteogenic differentiation of MSCs. Moreover, we also checked the effects of Tricin on the expression of key genes in Wnt/β-catenin signaling pathway. We found Tricin could promote proliferation of MSCs, as well as their mineralization. Tricin could also enhance the expression of osteogenesis marker genes including Bone sialoprotein, osteocalcin, Alkaline phosphatase, and RUNX2. Furthermore, we found out that neither siβ-catenin nor GSK-3β had effect on Tricin treatment, but siWnt3α could neutralize the effect of Tricin. Tricin can enhance osteoblastogenesis through the regulation of Wnt/β-catenin signaling pathway in human adult MSCs in vitro . [ABSTRACT FROM AUTHOR]

A novel type of antiviral agent for human cytomegalovirus (HCMV) is required, because the appearance of ganciclovir (GCV) resistant viruses has been reported. Tricin (4′,5,7-trihydroxy-3′,5′-dimethoxyflavone) has been shown to suppress significantly HCMV replication in human embryonic lung (HEL) fibroblast cells. Recently, we revealed that the action of tricin is different from that of GCV and cyclin-dependent kinase 9 (CDK9) is one of the target proteins of tricin. These results suggested that tricin is considered as a novel type of anti-HCMV agent. However, its anti-HCMV potency is not greater than that of GCV. This study tried to develop novel compounds with much greater anti-HCMV activity than GCV. We first made modifications to tricin by introducing fluorine atom, and then performed molecular docking simulations using the designed compounds and CDK9. The calculated binding energies showed that 6F-tricin (6-fluoro-4′-hydroxy-3′,5′-dimetoxyflavone) binds to CDK9 much stronger than tricin. Based on these results, 6F-tricin was synthesized, and then its anti-HCMV effect was analyzed in HEL cell cultures. As a result, 6F-tricin strongly suppressed HCMV replication in a dose-dependent manner. The anti-HCMV activity with a 50% effective concentration (EC 50 ) was 0.126 nM, corresponding to about 1/200 and 1/400 of EC 50 of GCV (27.5 nM) and tricin (54.3 nM), respectively. Moreover, 6F-tricin had no cytotoxicity against HEL cells at concentrations up to 10 μM. We further performed detailed analysis on the amino acid contributions to the binding energies and found that the strong binding affinity for 6F-tricin to CDK9 is attributed to the specific binding orientation of 6F-tricin in the ATP-binding site. These results suggest that 6F-tricin is a promising candidate for anti-HCMV drug development. [ABSTRACT FROM AUTHOR]

We previously reported that treatment with tricin (4 ′ ,5,7-trihydroxy-3 ′ ,5 ′ -dimethoxyflavone) after human cytomegalovirus (HCMV) infection significantly suppressed both infectious virion production and HCMV replication in human embryonic lung fibroblast (HEL) cells. Moreover, we recently demonstrated that HCMV infection can increase the expression of CC-motif ligand 2 (CCL2/MCP-1) and of CCR2, a CCL2-specific receptor, effects that can in turn enhance HCMV infection and replication. Hence, we here examined whether the CCL2-CCR2 axis is involved in the anti-HCMV effects of tricin in HEL cells. Tricin exposure yielded dose-dependent decreases in the accumulation of transcripts for the HCMV immediate early gene and the DNA polymerase gene in HCMV-infected cells, along with decreased production of infectious HCMV. Concomitantly, tricin caused dose-dependent attenuation of HCMV infection-induced up-regulation of expression of CCL2 and CCR2 mRNAs and of CCL2 protein. Moreover, CCL2 reversed tricin-mediated inhibition of HCMV virion production in a dose-dependent manner. Thus, tricin appears to exert anti-HCMV activity by depressing CCL2 expression. [ABSTRACT FROM AUTHOR]

• Flavones mixed with sugarcane fiber modulate the fecal microbiota composition. • Flavones mixed with sugarcane fiber increase the relative abundance of Prevotella. • Sugarcane fiber improves SCFA production throughout in vitro batch fermentation. This study investigated the effects of the sugarcane flavones diosmin, diosmetin, luteolin, and tricin, and their interactions with sugarcane fiber on the modulation of gut microbiota using in vitro batch fermentation. The alteration of fecal fermentation bacterial profile was analyzed using 16S rRNA sequencing data, while the bioavailability of fiber was indicated by short-chain fatty acid (SCFA) production and metabolism of polyphenols was measured directly by phenolic metabolites. Application of diosmin, diosmetin, luteolin, and tricin without fiber had no significant effect on the overall microbiota profile after 24 h of fermentation. When fiber alone was added, total SCFA production increased, specifically that of propionic and valeric acids. However, when flavones were combined with fiber, synergistic effects on the modulation of relative abundances of different bacterial taxa was noted. In particular, the proportion of Prevotella spp. was significantly increased by the combinations of diosmin, luteolin, and tricin with fiber. [ABSTRACT FROM AUTHOR]

The anti-adipogenic effect of tricin (5, 7, 4'-trihydroxy-3',5'-dimethoxyflavone), a flavone frequently found in cereal crops, and its underlying molecular mechanism were evaluated in 3T3-L1 preadipocytes. Tricin treatment (5–20 µM) significantly inhibited triacylglycerol (TG) accumulation without showing cytotoxicity. The expression of protein kinase B (AKT) was decreased by 80% using 20 µM tricin. The inhibition of mammalian target of rapamycin (mTOR) by tricin led to a significant suppression of the protein levels of CCAAT/enhancer-binding protein alpha (C/EBP-α), peroxisome proliferator-activated receptor gamma (PPAR-γ) and nuclear sterol regulatory element-binding protein 1 (SREBP-1). These results suggest that tricin regulates adipogenesis by targeting the AKT/mTORC1/SREBP-1 pathway in the adipose tissue and it could be used as an anti-obesity agent. [ABSTRACT FROM AUTHOR]

Previous studies revealed the potent anti-inflammatory activity of tricin, the active component of Njavara rice bran. Here, we report the involvement of specific signaling pathways in the protective effect of tricin against LPS induced inflammation in hPBMCs and the role of tricin in modulating endothelial dysfunction in LPS induced HUVECs. Pretreatment with tricin (15 μM) significantly inhibited the release of TNF-α and was comparable to the specific pathway blockers like ERK inhibitor (PD98059), JNK inhibitor (SP600125) and p38 inhibitor (SB203580), whereas an increased release of TNF-α was observed in PI3K/Akt inhibitor (LY294002) treated cells. Tricin alone and combination treatment of tricin and SB203580 showed more significant inhibition of activation of COX-2 and TNF-α than that of SB203580 alone treated group. Combination treatment of tricin and LY294002 showed increased activation of COX-2 and TNF-α, proved that PI3K activation is essential for the anti-inflammatory effect of tricin. Studies conducted on HUVECs revealed the protective effect of tricin against endothelial dysfunction associated with LPS induced inflammation by inhibiting the activation of proinflammatory mediators like TNF-α, IFN-γ, MCP 1 by modulating NF-κB and MAPK signaling pathways. ELISA and flow cytometric analysis again confirmed the protection of tricin against endothelial damage, especially from the decreased activation of cell adhesion molecules like ICAM-1, VCAM-1 and E-Selectin upon tricin treatment. This work establishes the mechanism behind the potent anti-inflammatory activity of the flavonoid tricin. [ABSTRACT FROM AUTHOR]

It has been demonstrated as the first report that combination treatment with ganciclovir (GCV) and tricin (4′,5,7-trihydroxy-3′,5′ -dimethoxyflavone), a derivative of Sasa albo-marginata , after human cytomegalovirus (HCMV) infection has synergistic effects on both infectious virus production and HCMV DNA synthesis in the human embryonic fibroblast cell line MRC-5. In this paper, we examined the anti-HCMV effects of GCV plus various concentrations of tricin, and tricin plus various concentrations of GCV in MRC-5 cells. We found that expression of the HCMV UL54 gene was significantly inhibited by combination of GCV with tricin when compared with GCV mono-treatment. These results suggest that tricin is a novel compound for combination therapy with GCV against HCMV replication. In addition, reduced-dose combination therapy may provide a direction for treatment in patients with HCMV infection while reducing drug toxicity. [ABSTRACT FROM AUTHOR]

Oat hull ethyl acetate extract (50 μg/μL) significantly inhibited triglyceride accumulation in 3T3-L1 adipocytes without causing cytotoxicity. The major active compound in the extract was isolated and identified as 5,7,4′-trihydroxy-3′,5′-dimethoxyflavone, tricin by mass spectrometry and 1H and 13 C NMR analyses. The tricin content in oat hull was approximately 18 mg/kg dry weight, and tricin constituted 9.6% of the total phenolic compounds in oat hull extract. The treatment of 3T3-L1 cells either with extract or purified tricin resulted in decreased lipid accumulation. The extract significantly decreased the activity of glycerol-3-phosphate dyhydrogenase, a marker of adipocyte differentiation in a dose dependent manner. The expression of major transcription factors, such as peroxisome proliferator-activated receptor (PPAR)-γ, CCATT/enhancer binding protein-α (CEBP/α), sterol regulatory binding protein 1 (SREBP1) and fatty acid synthase (FAS) was also significantly suppressed by the extract. When commercial purified tricin was added to 3T3-L1 cells the expression of all transcription factors were significantly decreased as low as 1.5 μg/μL treatment. These results suggest that oat hull extract containing tricin possesses anti-adipogeneic effect. [ABSTRACT FROM AUTHOR]

Two major residues are produced by the sugarcane industry, the fibrous fraction following juice extraction (bagasse), and the harvest residue (straw). The structures of the lignins from these residues were studied by pyrolysis coupled to gas chromatography-mass spectrometry (Py-GC/MS), nuclear magnetic resonance (NMR), and derivatization followed by reductive cleavage (DFRC). Whereas the lignin from bagasse has a syringyl-rich p -hydroxyphenyl:guaiacyl:syringyl (H:G:S) molar composition of 2:38:60, the lignin from straw is guaiacyl-rich (H:G:S of 4:68:28). The compositional differences were also reflected in the relative abundances of the different interunit linkages. Bagasse lignin was primarily β– O –4′ alkyl-aryl ether substructures (representing 83% of NMR-measurable linkages), followed by minor amounts of β–5′ (phenylcoumarans, 6%) and other condensed substructures. The lignin from straw has lower levels of β-ethers (75%) but higher relative levels of phenylcoumarans (β–5′, 15%) and dibenzodioxocins (5–5/4– O –β, 3%), consistent with a lignin enriched in G-units. Both lignins are extensively acylated at the γ-hydroxyl of the lignin side-chain (42% and 36% acylation in bagasse and straw), predominantly with p -coumarates (preferentially on S-units) but also with acetates (preferentially on G-units) to a minor extent. Tetrahydrofuran structures diagnostically arising from β–β-coupling (dehydrodimerization) of sinapyl p -coumarate or its cross-coupling with sinapyl alcohol were found in both lignins, indicating that sinapyl p -coumarate acts as a monomer participating in lignification. The flavone tricin was also found in the lignins from sugarcane, as also occurs in other grasses. [ABSTRACT FROM AUTHOR]

Njavara is an indigenous medicinal rice variety traditionally used in Ayurvedic system of medicine practiced in Kerala, India. Tricin is a bioflavonoid present in significantly higher levels in rice bran of Njavara. Present study attempted to identify the molecular target of tricin in TLR mediated signaling pathways by using lipopolysaccharide (LPS) induced human peripheral blood mononuclear cells (hPBMCs) and carrageenan induced paw edema in rats as experimental models. Tricin acted upstream in the activation of inflammation cascade by interfering with TLR4 activation, preferably by blocking the LPS induced activation of TLR4, MYD88 and TRIF proteins in hPBMCs. Subsequently, tricin significantly blocked the activation of downstream kinases like p38MAPK, JNK1/2 and IRF3. Thus the inhibitory effect of tricin on NF-κB and IRF3 together confirms the specific inhibition of both MYD88 dependent and TRIF dependent pathways. Tricin treatment also inhibited the pro-inflammatory effect of LPS by blocking the TLR4 signaling mediated activation of cytosolic phospholipase A 2 (cPLA 2 ), which is confirmed by specific inhibition of COX-2. Results demonstrated that in addition to NF-κB, tricin can prevent the activation of STAT proteins by significantly inhibiting the activation of both STAT1 and STAT3 via the down regulation of upstream phosphorylating enzymes like JAK1 and JAK2. The protective anti-inflammatory effect of tricin was also confirmed by in vivo experiments. Thus, this study provides strong evidence that tricin exerts its anti-inflammatory effect via a mechanism involving the TLR4/NF-κB/STAT signaling cascade. [ABSTRACT FROM AUTHOR]

Highlights: [•] Elevated CO2 enhanced carbon accumulation in rice during its entire life cycle. [•] However, plants grown at elevated CO2 had low levels of phenolic compounds. [•] At maturity, elevated CO2 increased the concentrations of phenolic compounds in rice. [•] Following acclimation of photosynthesis, phenolics were increased by elevated CO2. [•] Following a disease attack, levels of phenolics were also increased by elevated CO2. [Copyright &y& Elsevier]

Abstract: The flavone, tricin (5,7,4′-trihydroxy-3′,5′-dimethoxyflavone) has great potential as an anticancer agent, due to its specific chemopreventive activity. In spite of these characteristics, its use in preclinical studies is still limited, mainly because of its limited availability and high production cost. Tricin is found mainly in cereal grains, such as wheat, rice, barley, oat and maize. However, its concentration in these plants is not sufficient for commercial use. To find a reliable, rich source of tricin, we investigated its distribution in different parts of wheat (Triticum aestivum) and designed an efficient method for its isolation and purification. The highest amount (770±157mg/kg dry weight) was found in the husks of winter wheat. This concentration is one of the highest in any plant species and is considered as a cheap source of natural tricin. The purified wheat husks tricin was found to be a selective potent inhibitor of two cancer cell lines of liver and pancreas, while having no side effects on normal cells. This selective action suggests that tricin could be considered as a potential candidate for pre-clinical trials as a chemopreventive agent. In addition, fibre-rich crude wheat husk could be used as a natural chemopreventive agent in food supplement. [Copyright &y& Elsevier]

Abstract: Tricin was evaluated as a type of tyrosinase inhibitor with good efficacy compared to arbutin. Tricin functioned as a non-competitive inhibitor of tyrosinase, with an equilibrium constant of 2.30mmol/L. The molecular mechanisms underlying the inhibition of tyrosinase by tricin were investigated by means of circular dichroism spectra, fluorescence quenching and molecular docking. These assays demonstrated that the interactions between tricin and tyrosinase did not change the secondary structure. The interaction of tricin with residues in the hydrophobic pocket of tyrosinase was revealed by fluorescence quenching; the complex was stabilized by hydrophobic associations and hydrogen bonding (with residues Asn80 and Arg267). Docking results implied that the possible inhibitory mechanisms may be attributed to the stereospecific blockade effects of tricin on substrates or products and flexible conformation alterations in the tyrosinase active center caused by weak interactions between tyrosinase and tricin. The application of this type of flavonoid as a tyrosinase inhibitor will lead to significant advances in the field of depigmentation. [Copyright &y& Elsevier]

Abstract: In plants, O-methylation is mediated by an enzyme family of O-methyltransferases (OMTs) that transfer the methyl groups from the methyl donor, S-adenosyl-L-methionine (AdoMet) to suitable phenolic acceptor molecules. In a previous study [1], a flavonoid OMT (TaOMT2) was isolated and characterized from wheat (Triticum aestivum L.) leaves. Its novel gene product catalyzes three sequential O-methylations of the flavone tricetin (5,7,3′,4′,5′-pentahydroxyflavone) to its 3′-monomethyl-(selgin)→3′,5′-dimethyl-(tricin)→3′,4′,5′-trimethyl (TMT) ether derivatives, with tricin being the major product of the reaction. In this report, the biological significance of tricetin methylation was investigated by measuring the OMT activity, its expression level, and the accumulation of its major product (tricin) at different stages of development of wheat plants exposed to different abiotic stresses such as cold, salt and drought. The results showed that tricin accumulates mostly in wheat inflorescences under normal conditions compared to leaves and other developmental stages. Tricin accumulation was associated with increased TaOMT2 expression level and its enzyme activity, suggesting a possible de novo synthesis of the enzyme at this important developmental stage. This phenomenon may be attributed to the putative role of tricin in protecting seeds against biotic and abiotic stresses. The functions of tricin during growth and development of wheat and the importance of tricetin methylation during abiotic stresses are discussed. [Copyright &y& Elsevier]

Abstract: It has been reported that treatment with tricin (4′,5,7-trihydroxy-3′,5′-dimethoxyflavone), a derivative of Sasa albo-marginata, after human cytomegalovirus (HCMV) infection significantly suppressed both infectious virus production and HCMV replication in the human embryonic fibroblast cell line MRC-5. In this paper, we examined the mechanisms for the anti-HCMV effects of tricin in MRC-5 cells. Exposure of fibroblasts to tricin inhibited infectious HCMV production, with concomitant decreases in levels of transcripts of the CXC chemokine IFN-inducible T cell alpha chemoattractant (I-TAC or CXCL11) gene. We also found that the transcripts of the HCMV immediate early (IE) gene and replication of HCMV were lower in CXCL11 gene-knockdown cells. These results suggest that tricin is a novel compound with potential anti-HCMV activity and that CXCL11 is one of the chemokines involved in HCMV replication. In addition, it is possible that CXCL11 is the one of the targets of tricin. [Copyright &y& Elsevier]

Abstract: Flavonoids are a group of natural substances that are located in sources of vegetal origin and are able to regulate acute and chronic inflammatory responses. The anti-oxidant and anti-inflammatory effects corroborate with the preferential use of Njavara, a rice variety in indigenous medicine and the phytochemical investigations revealed the occurrence of a flavonoid, tricin at significantly higher levels compared to staple varieties. This study describes the new aspects of inflammatory suppression by the Njavara rice by evaluating the role of active constituent, tricin in the regulation of production of various pro‐inflammatory markers by human peripheral blood mononuclear cells stimulated with lipopolysaccharide. Treatment with tricin resulted in significant down‐regulation of LPS-elicited production of TNF-α, IL-6, PGE2 and NO. Tricin was found to be a potential blocker of the expression of isoforms of nitric oxide synthase, cyclooxygenase and matrix metalloproteinases. Modulation of the cascade of molecular events in lipopolysaccharide signaling also includes inhibition of transcription factor NF-κB evidenced by the detection of enhanced p65 subunit in the nuclear extracts on tricin supplementation. The present study summarizes the role of the flavonoid, tricin in the modulation of the expression of different inflammatory mediators and revealed that the inhibitory effects on cell signaling pathways are responsible for its anti-inflammatory activity. [Copyright &y& Elsevier]

Abstract: The anti-human cytomegalovirus (HCMV) activity of tricin (4′,5,7-trihydroxy-3′,5′-dimethoxyflavone), a derivative from Sasa albo-marginata, was studied in the human embryonic fibroblast cell line MRC-5. In a plaque assay, tricin and ganciclovir (GCV) showed concentration-dependent inhibitory properties from 0.05 to 3.6μM and 0.01 to 1.0μM, respectively. Tricin had no virucidal effects on cell-free HCMV. Treatment with tricin 1h before, or 1h or 3h after viral infection significantly suppressed HCMV replication. Moreover, tricin inhibited the expression of immediate early (IE) 2 mRNA and DNA polymerase (UL54) mRNA in HCMV-infected cells. Western blot analysis also demonstrated that tricin decreased the expression of IE antigen (especially IE2) and cyclooxygenase 2 (COX-2) expression in HCMV-infected cells. In the presence of tricin, prostaglandin E2 (PGE2) accumulation by HCMV infection was completely inhibited. These results suggest that tricin is a novel compound with potential COX inhibitor-dependent anti-HCMV activity. [Copyright &y& Elsevier]

Abstract: The present work reports amounts of flavonoids and phenylpropanoids of culms of three sugarcane varieties and of raw juice, syrup, molasse and VHP sugar. The antioxidant activity of those materials was evaluated by the DPPH and β-carotene/linoleic acid methods. The predominant phenolics in culms were phenylpropanoids (caffeic, chlorogenic and coumaric acids), while flavones (apigenin, tricin and luteolin derivatives) appeared in lower amounts. Differences were noted either among phenolic profiles of sugarcane culms or between culms and sugarcane products. The antioxidant activities of solutions from most samples were similar or higher than a 80μM Trolox solution. [ABSTRACT FROM AUTHOR]

Papyrus (Cyperus papyrus L.) is a plant with high productivity rate that is considered an interesting raw material for obtaining biofuels and biomaterials. In the present work, the composition and structural features of the lignins present in the rind and pith of papyrus culms have been studied. The analyses revealed that the lignins from both parts of papyrus culms differed greatly not only in their contents but also in composition and structure. In the rind, the lignin represented up to 27.0% (dry-matter) and was composed mainly of G-units (H:G:S composition of 4:63:33), while the lignin in the pith (15.7% dry-matter) presented a slightly higher amount of S-units (H:G:S composition of 8:43:49). These lignins also presented considerable amounts of cinnamates (p -coumarates and ferulates) incorporated. The differences in composition influenced the content of the lignin inter-unit linkages. Thus, the rind lignin presented lower amounts of β– O –4′ ether linkages (77% of all identified linkages) and higher content of condensed structures, such as phenylcoumarans (15%), resinols (2%), dibenzodioxocins (3%), and spirodienones (2%), while the pith lignin contained more β– O –4′ ethers (85% of all identified linkages) and lower amounts of phenylcoumarans (11%), tetrahydrofurans (2%), and spirodienones (2%). Moreover, 2D NMR analyses revealed that the lignins from papyrus were highly acylated at the γ-OH (40% acylation in the rind, and 60% acylation in the pith). DFRC analyses proved that p -coumarates were the main acylating groups, and that they were predominantly acylating the S-lignin units. Finally, the analyses also showed the presence of important amounts of the flavanone tricin in the rind lignin and, at lower amounts, in the pith lignin. [Display omitted] • Papyrus is an herbaceous plant with high biomass productivity rate. • The rind and the pith showed great differences in lignin content and composition. • Rind lignin was enriched in G-units, while pith lignin had a higher content of S-units. • Papyrus lignins were extensively acylated at the γ-OH with p -coumarates. [ABSTRACT FROM AUTHOR]

Abstract: The antioxidant compounds oryzanols, tocols and ferulic acid were identified in the methanolic extracts of defatted rice bran (DRB) by high pressure liquid chromatography (HPLC). The crude methanolic extract (CME) was partially purified by re-extraction with acetone to give an acetone extract (AE). For further purification of the acetone extract, sequential solvent extraction was employed yielding a lipophilic phase (AE-LP) with hexane and a polar phase (AE-PP) with acetone. The antioxidant potential of the DRB extracts and their phytochemical constituents in bulk oils were evaluated using the Schall oven test (SOT) and differential scanning calorimetry (DSC). The extracts were effective in inhibiting lipid oxidation as assessed by peroxide value, diene value and p-anisidine value. The activity of the extracts with respect to the inhibition of primary oxidation products followed the order AE-PP>AE-LP=AE>CME with the activity of AE-PP being equivalent to that of butylated hydroxytoluene (BHT) at a 200ppm level. However, tertiarybutylhydroquinone (TBHQ) was most active as compared to extracts and pure compounds with AE-PP showing about 45% of the activity of TBHQ at 200ppm level. Defatted rice bran extracts proved to be effective even at the high temperature employed in DSC. The antioxidant efficacy of AE-PP was close to that of TBHQ and far greater than that of BHT at a 200ppm level as evident from DSC results. The increase in activity with purification might be due to the enhanced levels of antioxidants in purified extracts compared to CME. [Copyright &y& Elsevier]

Abstract: From sugarcane juice, a flavone, identified by spectroscopic methods as tricin-7-O-β-(6″-methoxycinnamic)-glucoside, was isolated, in addition to orientin. The tricin derivative was shown to have antioxidant activity higher than Trolox® by means of the DPPH assay and lower by the β-carotene/linoleic acid system. It showed in vitro antiproliferative activity against several human cancer cell lines, with higher selectivity toward cells of the breast resistant NIC/ADR line. [Copyright &y& Elsevier]

Recent contributions to the role of phenolics, especially flavonoids, in different aspects of insect–plant interactions are reviewed, including data on the effects of rutin on the feeding behaviour of a range of noctuid larvae. [Copyright &y& Elsevier]

Leaves of Hyparrhenia hirta yielded the rare diastereoisomeric flavonolignans tricin 4′-O-(erythro-β-guaiacylglyceryl) ether and tricin 4′-O-(threo-β-guaiacylglyceryl) ether together with their 7-O-glucosides, which are the first flavonolignan glycosides to be isolated as natural products. A complete set of 1H and 13C NMR resonance assignments obtained for both flavonolignan aglycones indicates the need for revision of data published previously for these compounds and for a reassessment of their original stereochemical designation. [Copyright &y& Elsevier]

An investigation was carried out to find whether enhanced levels of UV-B radiation induce increased concentrations of flavonoids in the leaves of the grass species Deschampsia antarctica, Deschampsia borealis and Calamagrostis epigeios and the sedge Carex arenaria. Whether the enhanced levels of UV-B influenced the proportions of the various flavonoids in the leaves was also studied. Increased flavonoid concentrations would improve the UV-B shielding of UV-B susceptible tissues. Using HPLC analysis the flavonoids orientin and luteolin were identified in D. antarctica, orientin in D. borealis and tricin in C. arenaria. Neither flavonoid concentrations nor the proportion of the various flavonoids in climate room grown D. antarctica and D. borealis plants differed between individuals grown under 0, ambient or elevated UV-B levels. After 12 weeks of growth biomass production and shoot-to-root ratios of D. antarctica were not affected by elevated UV-B radiation. Greenhouse grown C. epigeios plants contained higher concentrations and different proportions of flavonoids grown under elevated levels of UV-B than when grown under ambient or 0 UV-B. In C. epigeios plants grown in their natural habitat in the field under ambient or elevated levels of UV-B, flavonoid concentrations and proportions were the same in plants from both treatments. In the leaves of the sedge C. arenaria grown in a greenhouse flavonoid concentrations and proportions were not affected by UV-B radiation. Leaves were harvested four times during the growing season from C. arenaria plants grown in their natural habitat in the field under ambient or elevated levels of UV-B. Leaves harvested in January contained higher concentrations of flavonoids when grown under elevated UV-B than when grown under ambient UV-B radiation. In leaves harvested in May, September and December flavonoid concentrations were the same in plants grown under ambient or elevated UV-B. The proportion of the different flavonoids was the same for both treatments in all months. These results indicate that constitutive levels of flavonoids in these grass and sedge species are adequately high to protect them against ambient and elevated levels of solar UV-B radiation. [Copyright &y& Elsevier]

Background: Ulcerative colitis is a subtype of inflammatory bowel disease, characterized by relapsing inflammation in the gastrointestinal tract with limited treatment options. Previous studies suggested that the natural compound tricin, a flavone isolated from rice bran, could suppress chemically-induced colitis in mice, while our recent study also demonstrated the anti-metastatic effect of tricin in colon tumor-bearing mice.Hypothesis/purpose: Here we further investigated the underlying mechanism of the inhibitory effects of tricin on lipopolysaccharides-activated macrophage RAW264.7 cells and explored the efficacy of tricin in acute colitis mouse model induced by 4.5% dextran sulfate sodium (DSS) for 7 days.Methods: Tricin (75, 100, and 150 mg/kg) or the positive control drug sulfasalazine (200 mg/kg) were orally administered to mice for 7 days. Stool consistency scores, stool blood scores, and body weight were recorded daily. Disease activity index (DAI) was examined on day 7, and colon tissues were collected for biochemical analyses. The fecal microbiome of colitis mice after tricin treatment was characterized for the first time in this study using 16S rDNA amplicon sequencing.Results: Results showed that tricin (50 µM) remarkably reduced nitric oxide production in lipopolysaccharides-activated RAW264.7 cells and the anti-inflammatory activity of tricin was shown to act through the NF-κB pathway. Besides, tricin treatment at 150 mg/kg significantly reversed colon length reduction, reduced myeloperoxidase activities and DAI scores, as well as restored the elevated myeloid-derived suppressive cells population in acute colitis mice. The influence from DSS on gut microbiota, such as the increased population of Proteobacteria phylum and Ruminococcaceae family, was shown to be relieved after tricin treatment.Conclusion: Our present study firstly demonstrated that tricin ameliorated acute colitis by improving colonic inflammation and modulating gut microbiota profile, which supports the potential therapeutic use of tricin for colitis treatment. [ABSTRACT FROM AUTHOR]

• Tricin is associated with numerous health benefits for human nutrition. • Tricin shows many unique biological properties for chemoprevention. • The structure-activity relationship of tricin monomer is outlined. • The bioactivity of tricin is expressed through the signaling cascade reaction. Tricin (5,7,4′-trihydroxy-3′,5′-dimethoxyflavone) as a renewable and bioactive polyphenolic compound is widely distributed in monocots with free and conjugated forms. It is derived from the secondary metabolite of plants with an analogous biosynthetic pathway to other flavonoids. Due to its unique biological properties over other flavonoids, tricin has been linked to numerous health benefits for human nutrition. In recent years, tricin has been demonstrated to have excellent pharmacological bioactivities and has been proposed as a safe candidate for cancer chemoprevention. For throwing light on the structure-activity relationship of tricin monomer and its potential clinical application, the natural occurrence, physicochemical characteristics, bio/chemosynthesis, isolation and purification, biological properties involved metabolism in vitro and in vivo of tricin as well as its toxicology and bioavailability are critically reviewed, which aims at greatly moving forward the value-added applications of this natural bioactive material on food, human nutrition, and pharmacology. [ABSTRACT FROM AUTHOR]