Search Results (8)

Lead (Pb) induces oxidative stress, inflammation, and hepatorenal injury. We evaluated whether fenugreek (Trigonella foenum-graecum) seed powder (200 mg/kg) protects against subchronic Pb-acetate exposure in male albino mice. Sixty mice were randomized to six groups (n = 10): control (G1), fenugreek-only (G2), Pb 150 mg/kg (G3), and three co-exposure groups receiving fenugreek with Pb at 50, 100, and 150 mg/kg (G4–G6), gavaged daily for 8 weeks. LC–DAD–ESI–MS/MS of the seed batch tentatively identified 32 metabolites, dominated by flavonoid C-glycosides, luteolin dihydrogalloyl-glucosyl-pentosyl glucoside (15.90%), vicenin-3 (14.46%), vicenin-2 (9.66%), vicenin-1 (8.80%), kaempferol 7-O-rhamnosyl-glucoside (8.71%), with additional acylated phenolic conjugates. Pb exposure (G3) significantly reduced growth and intake, elevated serum ALT, AST, ALP, urea, and creatinine, raised blood Pb, and produced hepatic necrosis, vacuolation, and inflammation. Molecularly, Pb upregulated Nrf2, HO-1, SCD-1, TNF-α, and IL-6 and suppressed SOD-3. Fenugreek co-treatment attenuated all these changes across the three Pb doses, with greatest effect at the lowest Pb load (G4). Notably, fenugreek co-treatment reduced rather than further increased Nrf2 and HO-1 expression relative to Pb alone, a pattern most consistent with lowering the upstream oxidative stimulus rather than direct induction of these pathways. The seed’s polyphenolic profile—rich in vicenin-type C-glycosides and luteolin and kaempferol derivatives—offers a plausible chemical basis for the antioxidant, anti-inflammatory, and modest Pb-lowering effects observed; however, because whole seed powder was administered and metabolite identifications are tentative, these structure–activity relationships are presented as hypotheses for future bioactivity-guided fractionation rather than as demonstrated mechanisms. These preclinical findings support further investigation of fenugreek as a candidate dietary adjunct against environmental Pb exposure, contingent on protein-level validation, pharmacokinetic characterization, benchmarking against a standard chelator, and bioactivity-guided fractionation. Full article

Flourensia cernua is a bush that grows in the semi-desert regions of Mexico. It has been used in traditional medicine due to its healing properties and currently represents an alternative source of bioactive molecules for different areas of the agri-food and health industries. The objective of this study was to extract and characterize the purified polyphenolic compounds (PPCs) and essential oils (EOs) of F. cernua leaves, determine the total flavonoid content, evaluate the antioxidant activity by three different assays, and determine, for the first time, its inhibitory effect against enzymes involved in the degradation of carbohydrates (α-amylase and α-glucosidase). In addition, the analysis of functional groups (by FTIR-ATR assay) and the identification of the chemical constituents present in both essential oils and phenolic compounds were carried out by GC/MS and UPLC-QToF/MS², respectively. The results indicate that PPCs and EOs are rich in flavonoid-type compounds. In addition, they showed potential for free-radical scavenging and the inhibition of the lipid oxidation process. The analyzed EOs and PPCs had potential against α-amylase and α-glucosidase enzymes, which are related to high blood sugar levels. FTIR-ATR analysis allowed for the identification of functional groups characteristic of polyphenolic compounds and the chemical constituents of EOs. Finally, compounds such as caryophyllene, caryophyllene oxide, and germacrene-D were identified by GC/MS assay and luteolin 7-O-rutinoside and apigenin-6-C-glucosyl-8-C-arabinoside by UPLC/QToF-MS². The results indicate that the PPCs and EOs of F. cernua have the potential to be used as antioxidant and enzyme inhibitor agents. Full article

(1) Background: Wax gourd is an economically important vegetable crop in many tropical and sub-tropical countries in Asia. Fruit color is an important fruit quality trait, but the genetic, biochemical basis and regulatory network of fruit color variation in wax gourd are rarely studied. (2) Methods: In this study, two wax gourd inbred lines with different pericarp colors were used as materials to conduct joint metabolomic and transcriptomic analyses on mature fruit pericarp: B214 with yellow and B227 with dark green color. (3) Results: It was found that the chlorophyll content in the pericarp of B214 was significantly lower than that of B227, consistent with the down-regulation of several genes involved in the chlorophyll biosynthesis pathway, including hemA, hemB, hemC, hemF, chlH, chlI, chlM, POR, and CAO. The 229 metabolites showed differential accumulation levels between B214 and B227, and 4 anthocyanins, 5 flavanones, 25 flavones, 25 flavone C-glycosides, 12 flavonols, and 3 isoflavones were identified. In particular, cyanidin 3-O-glucoside, an anthocyanin contributing to the coloration of dark color, showed higher accumulation in B227 than in B214, probably due to the higher expression of genes of F3′H and glucosyl transferases (GTs) in B227. Transcription factors such as MYBs and bHLHs showed differential expressions between the two lines including bHLH14, a homolog of Arabidopsis AtbHLH14 that had significantly higher expression in B227 than in B214. bHLH14 was located in a region where the pericarp color (pc) locus was mapped, suggesting it may be a candidate gene for the pc locus. (4) Conclusions: This work supports the association of chlorophyll and flavonoid synthesis in wax gourd fruit color variation and also provides a good foundation for understanding the regulatory network for wax gourd coloration. Full article

Peel cracking and ostiole-end splitting (collectively termed cracking) are common disorders in ripe fig fruit, downgrading fruit quality and thus limiting marketability. This two-year field study addressed the possibility of alleviating cracking at harvest by two foliar salicylic acid (SA) sprays prior to harvest (8 and 5 d). Three SA concentrations (0, 1, and 2 mM) were employed in the first year, and based on the obtained results two (0 and 2 mM) in the second year. A local variety (‘Vasilika’) with excellent organoleptic profile, and high sensitivity to cracking was evaluated. Fruit was harvested at commercial maturity. Fruit marketability was mainly based on the incidence and severity of cracking. Fruit weight, peel color, flesh total soluble solids (TSS), titratable acidity (TA), and pH were estimated for fig quality. The contents of total anthocyanins (TAN), cyanidin-3-rutinoside (c-3-rut; the major anthocyanin in fig), and the expression of four genes coding for regulatory enzymes (phenylalanine ammonia lyase, anthocyanidin synthase, UDP-flavonoid glucosyl transferase 1, and UDP-flavonoid glucosyl transferase 2) of the phenylpropanoid biosynthetic pathway were also determined in the peel. Preharvest SA application (2 mM) increased the percentage of fruit without cracking (sound fruit) by 1.4–2.6-fold, and of marketable fruit (sound and slightly cracked) by 2-fold. SA application (2 mM) was associated with increased flesh TSS and TA, as well as with decreased flesh pH and peel red coloration in stripe. The treatment (2 mM SA) decreased both TAN and c-3-rut contents, which were highly associated (r = 0.978). Responses of transcription level of the four genes to SA application varied, and did not correlate with the other variables in the study. In conclusion, SA appears to be a low-cost and environmentally-safe agent for improving fig fruit quality and marketability, and facilitates harvesting and postharvest management of figs. Full article

Mangiferin is a natural antioxidant C-glucosidic xanthone originally isolated from the Mangifera indica (mango) plant. Mangiferin exhibits a wide range of pharmaceutical activities. However, mangiferin’s poor solubility limits its applications. To resolve this limitation of mangiferin, enzymatic glycosylation of mangiferin to produce more soluble mangiferin glucosides was evaluated. Herein, the recombinant maltogenic amylase (MA; E.C. 3.2.1.133) from a thermophile Parageobacillus galactosidasius DSM 18751^T (PgMA) was cloned into Escherichia coli BL21 (DE3) via the expression plasmid pET-Duet-1. The recombinant PgMA was purified via Ni²⁺ affinity chromatography. To evaluate its transglycosylation activity, 17 molecules, including mangiferin (as sugar acceptors), belonging to triterpenoids, saponins, flavonoids, and polyphenol glycosides, were assayed with β-CD (as the sugar donor). The results showed that puerarin and mangiferin are suitable sugar acceptors in the transglycosylation reaction. The glycosylation products from mangiferin by PgMA were isolated using preparative high-performance liquid chromatography. Their chemical structures were glucosyl-α-(1→6)-mangiferin and maltosyl-α-(1→6)-mangiferin, determined by mass and nucleic magnetic resonance spectral analysis. The newly identified maltosyl-α-(1→6)-mangiferin showed 5500-fold higher aqueous solubility than that of mangiferin, and both mangiferin glucosides exhibited similar 1,1-diphenyl-2-picrylhydrazyl free radical scavenging activities compared to mangiferin. PgMA is the first MA with glycosylation activity toward mangiferin, meaning mangiferin glucosides have potential future applications. Full article

Wildly grown in most regions of the world, Carissa edulis is a highly underutilised fruit with significant antioxidant characteristics. The phyto and physicochemical properties of C. edulis berries at different stages of ripening are evaluated in this work. Total flavonoids (TF), total phenolic content (TPC) and antioxidant activity were determined spectrophotometrically, while concentration of polyphenols was determined using liquid chromatography coupled to diode array detection and electrospray ionization mass spectrometry. Results showed that antioxidant activity was lowest (18.36 ± 0.12 mmol TE/g) in RS3 and decreased with TPC upon increased ripening. Conversely, TF increased with ripening progression with TF found to be highest in RS3 (5.92 ± 0.03 mg CE/g). Identified phenolic acids in C. edulis were quinic acid, protocatechuoyl-hexose, neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid and dicaffeoylquinic acid. Identified flavonoids included rutin, catechin, procyanidin dimer, procyanidin trimer, quercetin-3-O-glucosyl-xyloside, quercetin-3-O-robinobioside, quercetin-3-O-glucoside and quercetin-3-OH-3-methylglutaryl-glucoside. Physicochemical properties of C. edulis varied among samples with sugar/acid ratio of C. edulis ranging from 25.70 for RS1 to 50.36 for RS3. Ripening stage of C. edulis undoubtedly affects the phyto and physicochemical properties of C. edulis. Full article

With the lack of available drugs able to prevent the progression of Alzheimer’s disease (AD), the discovery of new neuroprotective treatments able to rescue neurons from cell injury is presently a matter of extreme importance and urgency. Here, we were inspired by the widely reported potential of natural flavonoids to build a library of novel flavones, chromen-4-ones and their C-glucosyl derivatives, and to explore their ability as neuroprotective agents with suitable pharmacokinetic profiles. All compounds were firstly evaluated in a parallel artificial membrane permeability assay (PAMPA) to assess their effective permeability across biological membranes, namely the blood-brain barrier (BBB). With this test, we aimed not only at assessing if our candidates would be well-distributed, but also at rationalizing the influence of the sugar moiety on the physicochemical properties. To complement our analysis, logD_7.4 was determined. From all screened compounds, the p-morpholinyl flavones stood out for their ability to fully rescue SH-SY5Y human neuroblastoma cells against both H₂O₂- and Aβ_1-42-induced cell death. Cholinesterase inhibition was also evaluated, and modest inhibitory activities were found. This work highlights the potential of C-glucosylflavones as neuroprotective agents, and presents the p-morpholinyl C-glucosylflavone 37, which did not show any cytotoxicity towards HepG2 and Caco-2 cells at 100 μM, as a new lead structure for further development against AD. Full article

Aurone glycosides display a variety of biological activities. However, reports about glycosyltransferases (GTs) responsible for aurones glycosylation are limited. Here, the transcriptome-wide discovery and identification of an aurone glycosyltransferase with glycosidase activity is reported. Specifically, a complementary DNA (cDNA), designated as OsUGT1, was isolated from the plant Ornithogalum saundersiae based on transcriptome mining. Conserved domain (CD)-search speculated OsUGT1 as a flavonoid GT. Phylogenetically, OsUGT1 is clustered as the same phylogenetic group with a putative 5,6-dihydroxyindoline-2-carboxylic acid (cyclo-DOPA) 5-O-glucosyltransferase, suggesting OsUGT1 may be an aurone glycosyltransferase. The purified OsUGT1 was therefore used as a biocatalyst to incubate with the representative aurone sulfuretin. In vitro enzymatic analyses showed that OsUGT1 was able to catalyze sulfuretin to form corresponding monoglycosides, suggesting OsUGT1 was indeed an aurone glycosyltransferase. OsUGT1 was observed to be a flavonoid GT, specific for flavonoid substrates. Moreover, OsUGT1 was demonstrated to display transglucosylation activity, transferring glucosyl group to sulfuretin via o-Nitrophenyl-β-d-glucopyranoside (oNP-β-Glc)-dependent fashion. In addition, OsUGT1-catalyzed hydrolysis was observed. This multifunctionality of OcUGT1 will broaden the application of OcUGT1 in glycosylation of aurones and other flavonoids. Full article