Luteolin Research Articles

CoAl2O4 nanoparticles modified carbon nanofibers as high-efficiency bifunctional electrocatalyst: An efficient electrochemical aqueous asymmetric supercapacitors and non-enzymatic electrochemical sensors

The thriving energy demand of the gradually increasing population and modernized life style requires development in energy storage devices for usage in commercial electronic devices. In this particular work, we have explored electrochemical performances of bimetallic oxide CoAl2O4 and tuned its performance by decorating it on the carbon nanofibers. The CoAl2O4/CNFs are synthesized by deep eutectic solvents based hydrothermal method. The synthesized CoAl2O4 nanoparticle was found electrochemically active and the incorporation of CNFs end up boosting, its electrochemical performances as battery-type electrode. The obtained nanocomposites were characterized by various techniques. The electrochemically active CoAl2O4/CNFs exhibited 2.2-fold higher charge storage capacity than CoAl2O4. The CoAl2O4/CNFs exhibited specific capacity as high as 132 C/g at a constant applied current density of 1 A/g in 1 M KOH. The asymmetric device fabricated with CoAl2O4/CNFs electrodes exhibited excellent energy density of 20 Wh/kg at power density of 3000 W/kg. The CoAl2O4/CNFs electrode long-term stability has been minutely observed; the high Coulombic efficiency of 90% and high rate of capacity retention 95 %. In this work, an enzyme-free electrochemical sensor based on CoAl2O4/CNFs composite was developed for the detection of luteolin (LUT). Further modification of CoAl2O4/CNFs composite can improve the high surface area and catalytic capability of the composites. Under the optimal detection conditions, the prepared sensor has good linearity in the detection of LUT within range 30 nM − 73.5 μM with a limit of detection (LOD) of 0.0124 μM (12.4 nM). The stability and selectivity of the sensor is high, and can be used to detect LUT in various real samples.

Luteolin-Induced Activation of Mitochondrial BKCa Channels: Undisclosed Mechanism of Cytoprotection.

Luteolin (LUT) is a well-known flavonoid that exhibits a number of beneficial properties. Among these, it shows cardioprotective effects, as confirmed by numerous studies. However, its effect on mitochondrial potassium channels, the activation of which is related to cytoprotection, as well as on heart ischemia/reperfusion (I/R) damage prevention, has not yet been investigated. The large conductance calcium-regulated potassium channel (mitoBKCa) has been identified in both the mitochondria of the vascular endothelial cells, which plays a significant role in the functioning of the cardiovascular system under oxidative stress-related conditions, and in the mitochondria of cardiomyocytes, where it is deeply involved in cardiac protection against I/R injury. Therefore, the aim of this study was to explore the role of the mitoBKCa channel in luteolin-induced cytoprotection. A number of in vitro, in vivo, ex vivo and in silico studies have confirmed that luteolin activates this channel in the mitochondria of cardiomyocytes and endothelial cells, which in turn leads to the protection of the endothelium and a significant reduction in the extent of damage resulting from myocardial infarction, where this effect was partially abolished by the mitoBKCa channel blocker paxilline. In conclusion, these results suggest that luteolin has cardioprotective effects, at least in part, through the activation of the mitoBKCa channel, shedding light on a new putative mechanism of action.

Comparative pharmacokinetic study of the five anti-inflammatory active ingredients of Inula cappa in a normal and an LPS-induced inflammatory cell model.

Inula cappa is a commonly used medicine in the Miao area of Guizhou Province in China. We established an in vitro inflammatory model of mouse macrophage RAW264.7 cells to study the different pharmacokinetics of five anti-inflammatory active ingredients in the I. cappa extract namely luteolin (LUT), chlorogenic acid (CA), cryptochlorogenic acid (CCA), 3,4-dicaffeoylquinic acid (3,4-DCQA) and 4,5-dicaffeoylquinic acid (4,5-DCQA), in a normal and an inflammatory cell model. First, RAW264.7 cells were treated in vitro with l μg/mL lipopolysaccharide (LPS) for 24 h to establish an inflammatory cell model. Then, the pharmacokinetic characteristics of the five ingredients were compared in normal and inflammatory cells after treatment with 200 μg/ml and 800 μg/ml of I. cappa extracts. After treatment with 1 μg/ml LPS for 24 h, the volume of RAW264.7 cells was increased, the morphology was changed, the antennae were obvious, and the secretion of inflammatory factors nitric oxide and TNF-α was increased. The pharmacokinetics results showed that the five ingredients in normal and inflammatory cells exhibited an increase in Cmax and AUC values with increasing doses, and the Cmax and AUC values of five ingredients were positively correlated with the extract concentration. Each of these five ingredients presented nonlinear pharmacokinetic characteristics. After treatment with 200 μg/ml of I. cappa extract, the uptake of five ingredients increased in inflammatory cells, Tmax was prolonged, MRT and t1/2 were prolonged, and CL_F and Vz_F were decreased, while after treatment with 800 μg/ml of I. cappa extract, the uptake of five ingredients decreased, Tmax was prolonged, absorption was faster, and MRT and t1/2 were prolonged. The five analyzed components in I. cappa extract exerted different effects on normal cells and LPS-induced inflammatory cells. Compared to normal cells, the uptake of five ingredients in inflammatory cells was faster and the AUC and Cmax values increased with increasing doses, showing a dose-dependent nonlinear pharmacokinetic profile. These results indicate that the pharmacokinetic effects of the five analyzed ingredients in I. cappa extract are changed in the inflammatory state.

Peanut Shell Extract and Luteolin Regulate Lipid Metabolism and Induce Browning in 3T3-L1 Adipocytes.

Peanut shells are agricultural waste products that require utilization. The freeze-dried ethanolic peanut shell extract (PSE) contained 10.01 ± 0.55 mg/g of luteolin (LUT) with a total polyphenol content of 18.11 ± 0.88 mg GAE/g. Thus, LUT is one of the major polyphenolic components in PSE. Although PSE displays antibacterial and neurotrophic activities, minimal research is available addressing its potential role in lipid metabolism. This study investigated the role of PSE in terms of inhibiting adipogenesis, accelerating lipolysis, and promoting lipid browning using the 3T3-L1 cell line. Without affecting cell viability, high concentrations of PSE and LUT prevented adipogenesis by reducing the mRNA levels of C/EBPα, PPARγ, and SREBP1-c, and increasing the protein levels of pACC and pAMPK. Moreover, PSE and LUT induced lipolysis by activating lipolytic proteins, and enhanced the protein expressions of the brown adipocyte-specific markers, UCP1, PGC-1α, and SIRT1 in fully differentiated 3T3-L1 adipocytes. Increased mitochondrial biosynthesis provided additional evidence in favor of these findings. Due to their anti-obesity properties, it is proposed that PSE and LUT could be used as potential dietary supplements.

Mucoadhesive nanoemulsion enhances brain bioavailability of luteolin after intranasal administration and induces apoptosis to SH-SY5Y neuroblastoma cells

Neuroblastoma is the most frequently diagnosed extracranial solid tumor in children and accounts for 7 % of all childhood malignancies and 15 % cancer mortality in children. Luteolin (LUT) is recognized by its anticancer activity against several types of cancer. The aim of this study was to prepare chitosan-coated nanoemulsion containing luteolin (NECh-LUT), investigate its potential for brain delivery following intranasal administration, and to evaluate its cytotoxicity against neuroblastoma cells. NECh-LUT was developed by cavitation process and characterized for its size, surface charge, encapsulation efficiency, and mucoadhesion. The developed formulation presented size 68 ± 1 nm, zeta potential + 13 ± 1 mV, and encapsulation efficiency of 85.5 ± 0.3 %. The NECh-LUT presented nearly 6-fold higher permeation through the nasal mucosa ex vivo and prolonged LUT release up to 72 h in vitro, following Baker-Lonsdale kinetic model. The pharmacokinetic evaluation of NECh-LUT revealed a 10-fold increase in drug half-life and a 4.4 times enhancement in LUT biodistribution in brain tissue after intranasal administration of single-dose. In addition, NECh-LUT inhibited the growth of neuroblastoma cells after 24, 48 and 72 h in concentrations starting from 2 µM. The NECh-LUT developed for intranasal administration proved to be a promising alternative for brain delivery of LUT, and a viable option for the treatment of neuroblastoma.

Evaluation of Diabetes Effects of Selenium Nanoparticles Synthesized from a Mixture of Luteolin and Diosmin on Streptozotocin-Induced Type 2 Diabetes in Mice.

The absence of a treatment efficient in the control of type 2 diabetes mellitus requires more functional products to assist treatment. Luteolin (LU) and diosmin (DIO) have been known as bioactive molecules with potential for the treatment of diabetes. This work aimed to establish the role that a combination of LU and DIO in selenium nanoparticles (SeNPs) played in streptozotocin (STZ)- induced diabetes mice. Green synthesis of Se NPs was performed by mixing luteolin and diosmin with the solution of Na2SeO3 under continuous stirring conditions resulting in the flavonoids conjugated with SeNPs. The existence of flavonoids on the surface of SeNPs was confirmed by UV-Vis spectra, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) images, and DLS graphs via Zetasizer. The average diameter of GA/LU/DIO-SeNPs was 47.84 nm with a PDI of −0.208, a zeta potential value of −17.6, a Se content of 21.5% with an encapsulation efficiency of flavonoids of 86.1%, and can be stabilized by gum Arabic for approximately 175 days without any aggregation and precipitation observed at this time. Furthermore, The C57BL/6 mice were treated with STZ induced-diabetes and were exposed to LU/DIO, SeNPs, and GA/LU/DIO-SeNPs for six weeks. The treatment by nanospheres (GA/LU/DIO-SeNPs) in the mice with diabetes for a period of 6 weeks restored their blood glucose, lipid profile, glycogen, glycosylated hemoglobin, and insulin levels. At the same time, there were significant changes in body weight, food intake, and water intake compared with the STZ- untreated induced diabetic mice. Moreover, the GA/LU/DIO-SeNPs showed good antioxidant activity examined by catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) in liver and kidney and can prevent the damage in the liver evaluated by aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) activities. The nanospheres exhibited a significant anti-diabetic activity with a synergistic effect between the selenium and flavonoids. This investigation provides novel SeNPs nanospheres prepared by a high-efficiency strategy for incorporating luteolin and diosmin to improve the efficiency in type 2 diabetes.

Choline oleate based micellar system as a new approach for Luteolin formulation: Antioxidant, antimicrobial, and food preservation properties evaluation

Luteolin (LUT), an important flavonoid, shows excellent antioxidant and antimicrobial properties. However, its low solubility and stability in water, as well as challenges related to its formulation, have limited its use in food preservation. Here, we develop a highly water-soluble LUT-loaded micellar formulation (LUT-MF) using a solid-in-water nanodispersion technique involving emulsification and lyophilization processes. LUT solubilized in an organic phase comprising acetone, methanol, and cyclohexane (5:10:85 v/v) was emulsified with an aqueous solution of a surface-active ionic liquid, choline oleate ([Cho][Ole]), and the oil in water emulsion was lyophilized to remove the organic phase and water and obtain a solid LUT-[Cho][Ole] complex. LUT-[Cho][Ole] complex was dispersed again in water to prepare the LUT-MF formulation with good stability. Dynamic light scattering and transmission electron microscopy confirmed that the LUT-MF formed spherical micelles with a mean particle size of approximately 73 nm. LUT-MF showed excellent encapsulation efficiency (94.3%) and enhanced aqueous solubility. An in vitro release study in PBS containing 30% ethanol demonstrated 3.94 times higher release of LUT from LUT-MF than from LUT suspension after 24 h. The developed formulation showed better antioxidant activity than both free LUT and ascorbic acid. LUT-MF demonstrated higher antibacterial activity than sodium benzoate. Food preservation studies revealed that treating strawberries with LUT-MF effectively preserved color and prevented shriveling and decay over 8 days storage at 10 °C, compared with sodium benzoate treatment. The results suggest that LUT-MF is a potential natural preservative alternative to conventional toxic chemical preservatives used in the food industry.

Templating precise multiple binding sites: Promising molecularly imprinted membrane orchestrated by sequential surface imprinting strategy

Olive mill wastewater (OMW) is a hazardous environmental effluent due to its high phenolic compounds (PCs) content. Novel strategies affording molecular precision and functional versatility are needed to recover PCs and reduce ecotoxicity. Luteolin (LTL) was selected as a typical PC in the OMW. In this study, we outlined a molecularly imprinted membrane (MPL@CSMIMs) orchestrated by a sequential surface imprinting strategy to selectively separate LTL. Dopamine (DA), as a multifunctional monomer, could self-polymerize in an alkaline solution to form the first LTL-imprinting procedure. A polydopamine (PDA) modulated bottom-up approach was regarded as a molecular linker to enhance the hydrophilicity and binding activity, as well as established a strong and stable adhesion platform for integrated structure. The second imprinting procedure was formed by atom transfer radical polymerization (ATRP). The covalent and non-covalent functional monomers (boronic acid and amino groups) were introduced to create the tailor-made second-imprinted sites. Adsorption isotherm and dynamics, permeation selectivity, and stability were investigated, possessing desirable rebinding ability (49.63 mg g−1) and permselectivity factors (βAGN/LTL = 5.80, βCTC/LTL = 12.82), respectively. In-situ diffuse reflection infrared Fourier transform spectroscopy (In-situ ATR-FTIR) analysis, molecular simulation, and X-ray photoelectron spectroscopy (XPS) analysis revealed that the templating precise adsorption property for LTL was mainly realized by the shape of LTL-imprinted sites and synergistic covalent and non-covalent interactions. Compared to one-step or one-pot imprinting approaches, the proposed sequential surface imprinting strategy offered a more flexible and precise combination to improve the selectivity of MIMs significantly. The efficiency of the sequential imprinting approach made it a competitive and appealing method to develop MIMs.

Physicochemical properties of chitosan edible films incorporated with different classes of flavonoids

Chitosan films were prepared by incorporating catechin hydrate (CH), quercetin dihydrate (QDH) and luteolin (LU) at 1, 3, 5 and 10% (w/w of chitosan). The physicochemical properties of the composite films were significantly affected by the type and the concentration of the flavonoids incorporated. All three composite films showed increased tensile strength (TS, 60–240%), elongation at break (EAB, 140–220%), solubility (50–55%), swelling degree (50–55%) thermal stability and opacity with increasing concentrations of the flavonoids up to 5%. However, TS, EAB and the thermal stability declined with further increase in the flavonoid concentration to 10%. The moisture content, luminosity (L), and the white index (WI) of the films declined (18–20%, 5–20%, and 5–30%, respectively) with increasing concentrations of the flavonoids. Fourier transform infrared (FTIR) spectra of the films confirmed interactions between flavonoids and chitosan, which were reflected by the changes in the physicochemical properties of the composite films. Storage of the films at both room (21 °C) and cold (4 °C) temperatures for six weeks caused reductions in EAB and increases in TS (approximately 100–200% and 40–80%). This study demonstrated that incorporating flavonoids at low levels up to 5% can improve the physicochemical properties of chitosan film.

Identifying Active Compounds and Mechanisms of Citrus changshan-Huyou Y. B. Chang against URTIs-Associated Inflammation by Network Pharmacology in Combination with Molecular Docking

Purpose The ripe fruits of Citrus changshan-huyou, known as Quzhou Fructus Aurantii (QFA), have been commonly used for respiratory diseases. The purpose of this study was to investigate their active compounds and demonstrate their mechanism in the treatment of upper respiratory tract infections (URTIs) through network pharmacology and molecular docking. Methods The prominent compounds of QFA were acquired from TCMSP database. Their targets were retrieved from SwissTargetPrediction database, and target genes associated with URTIs were collected from DisGeNET and GeneCards databases. The target protein-protein interaction (PPI) network was constructed by using STRING database and Cytoscape. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were enriched. Visual compound-target-pathway network was established with Cytoscape. The effects of compounds were verified on the inhibitory activities against phosphoinositide 3-kinases (PI3Ks). Finally, the molecular docking was carried out to confirm the binding affinity of the bioactive compounds and target proteins. Results Five important active compounds, naringenin (NAR), tangeretin (TAN), luteolin (LUT), hesperetin (HES), and auraptene (AUR), were obtained. The enrichment analysis demonstrated that the pathways associated with inflammation mainly contained PI3K/Akt signalling pathway, TNF signalling pathway, and so on. The most important targets covering inflammation-related proteins might be PI3Ks. In vitro assays and molecular docking exhibited that TAN, LUT, and AUR acted as PI3Kγ inhibitors. Conclusion The results revealed that QFA could treat URTIs through a multi-compound, multi-target, multi-pathway network, in which TAN, LUT, and AUR acted as PI3Kγ inhibitors, probably contributing to a crucial role in treatment of URTIs.

Luteolin Phosphate Derivatives Generated by Cultivating Bacillus subtilis var. Natto BCRC 80517 with Luteolin.

Luteolin (LUT), a plant-derived flavone, exhibits various bioactivities; however, the poor aqueous solubility hampers its applications. Here, we revealed bioconversion of LUT by Bacillus subtilis BCRC 80517, yielding three water-soluble phosphate conjugates. These derivatives were identified as luteolin 4'-O-phosphate (L4'P), luteolin 3'-O-phosphate (L3'P), and luteolin 7-O-phosphate (L7P) by LC-ESI-MS/MS and NMR. Besides, we found that Bacillus subtilis BCRC 80517 was able to convert different levels of LUT but showed a limited conversion rate. By observing bacterial morphology with transmission electron microscopy and confocal fluorescence microscopy, we found that LUT disrupted the bacterial membrane integrity, which explained the incomplete conversion. Additionally, we revealed a spontaneous intramolecular transesterification of L4'P to L3'P, the thermodynamically more stable form, under acidic conditions and proposed the possible mechanism involving a cyclic phosphate as the intermediate. This study provides insight into development of a potent structural modification strategy to enhance the solubility of LUT through biophosphorylation.

The challenge of flavonoid/cyclodextrin complexation in a complex matrix of the quercetin, luteolin, and 3-O-methylquercetin

The complexation of herbal constituents with cyclodextrin has been a useful tool to improve their aqueous solubility. However, the simultaneous complexation of these compounds still lacks detailed studies. The present study investigated the multicomplexation of quercetin (QCT), luteolin (LUT), and 3-O-methylquercetin (3OMQ) with (2-hydroxypropyl)-β-cyclodextrin (HPβCD), when they are simultaneously contained in a flavonoid-enriched fraction (FEF) of Achyrocline satureioides. The phase-solubility diagram revealed a linear correlation between the flavonoids solubility and the HPβCD concentration, demonstrating the formation of complexes with a 1:1 stoichiometric ratio, which was confirmed by ESI-MS. Negative ΔG0 values indicated that complexation was spontaneous. Flavonoids/HPβCD interactions were evidenced by FT-IR, DSC, SEM, and 1D and 2D NMR. The last one showed the formation of inclusion complexes by insertion of the B-ring of the flavonoids into the cavity of HPβCD. Unexpectedly, the FEF/HPβCD complex showed a radical scavenger potential lower than the FEF. The HPLC analysis revealed that the complex contained different flavonoid ratio than the fraction. Thus, the antioxidant capacity of the samples was demonstrated to be related to the ratio among the flavonoids, rather than to the total flavonoids. These new findings are very useful for developing herbal cyclodextrin-based products from A. satureioides or other herbal products.

Comparative Study of the Pharmacological Properties of Luteolin and Its 7,3'-Disulfate.

The global spread of the metabolic syndrome, oncological and viral diseases forces researchers to pay increased attention to the secondary metabolites of marine hydrobionts, which often have a high therapeutic potential in the treatment of these pathologies and are effective components of functional food. The flavone luteolin (LT), as one of the most widely distributed and studied plant metabolites, is distinguished by a diverse spectrum of biological activity and a pleiotropic nature of the mechanism of action at the molecular, cellular and organismal levels. However, there is still practically no information on the spectrum of biological activity of its sulfated derivatives, which are widely represented in seagrasses of the genus Zostera. In the present work, a comparative study of the pharmacological properties of LT and its 7,3′-disulfate was carried out with a brief analysis of the special role of sulfation in the pharmacological activity of flavonoids.

Effects of ultrasonic pretreatment of soybean protein isolate on the binding efficiency, structural changes, and bioavailability of a protein-luteolin nanodelivery system

The combination of protein and flavonoids can ameliorate the problems of poor solubility and stability of flavonoids in utilization. In this study, soybean protein isolate pretreated by ultrasonication was selected as the embedding wall material, which was combined with luteolin to form a soybean protein isolate-luteolin nanodelivery system. The complexation effect and structural changes of soybean protein isolate (SPI) and ultrasonic pretreatment (100 W, 200 W, 300 W, 400 W and 500 W) of soybean protein isolate with luteolin (LUT) were compared, as well as the changes in digestion characteristics and antioxidant activity in vitro. The results showed that proper ultrasonic pretreatment increased the encapsulation efficacy, loading amount and solubility to 89.72%, 2.51 μg/mg and 90.56%. Appropriate ultrasonic pretreatment could make the particle size and the absolute value of ζ-potential of SPI-LUT nanodelivery system decrease and increase respectively. The FTIR and fluorescence results show that appropriate ultrasonic pretreatment could reduce α-helix, β-sheet and random coil, increase β-turn, and enhance fluorescence quenching. The thermodynamic evaluation results indicate that the ΔG < 0, ΔH > 0 and ΔS > 0, so the interaction of LUT with the protein was spontaneous and mostly governed by hydrophobic interactions. The XRD results show that the LUT was amorphous and completely wrapped by SPI. The DSC results showed that ultrasonic pretreatment could improve the thermal stability of SPI-LUT nanodelivery system to 112.66 ± 1.69 °C. Digestion and antioxidant analysis showed that appropriate ultrasonic pretreatment increased the LUT release rate and DPPH clearance rate of SPI-LUT nanodelivery system to 89.40 % and 55.63 % respectively. This study is a preliminary source for the construction of an SPI nanodelivery system with ultrasound pretreatment and the deep processing and utilization of fat-soluble active substances.

Combined Curcumin and Luteolin Synergistically Inhibit Colon Cancer Associated with Notch1 and TGF-β Signaling Pathways in Cultured Cells and Xenograft Mice.

Simple SummaryOne of the significant issues of the anti-cancer effects of phytochemicals, bioactive compounds from foods, and other plants, is that the effective dosages of the phytochemicals are too high to be obtained by oral intake, particularly by food intake. The current study aimed to assess if the combination of two phytochemicals, luteolin (LUT) and curcumin (CUR), at low dosages where LUT or CUR alone has no significant effect, synergistically exerts anti-colon cancer. Our results show that combined LUT and CUR synergistically suppressed colon cancer in cultured cells and cell-derived xenograft mice, which may be associated with two possible molecular pathways. This study provides a practical approach to treating or preventing colon cancer in humans by consuming foods having high levels of luteolin and curcumin.This study aimed to select a combination of curcumin and luteolin, two phytochemicals from food, at lower concentrations with a higher inhibitory effect on colon cancer growth and investigate possible molecular mechanisms of this anti-colon cancer effect. By pairwise combination screening, we identified that the combination of curcumin (CUR) at 15 μM and luteolin (LUT) at 30 μM (C15L30) synergistically suppressed the proliferation of human colon cancer CL-188 cells, but the individual chemicals had a little inhibitory effect at the selected concentrations. This result was also confirmed in other colon cancer DLD-1cells, suggesting that this synergistic inhibitory effect of C15L30 applies to different colon cancer cells. The combination C15L30 synergistically suppressed the wound closure (wound healing assay) in CL-188 cells. We also found that the combination of CUR and LUT (at 20 mg/kg/day and 10 mg/kg/day, respectively, IP injection, 5 days for 2 weeks) synergistically suppressed tumor growth in CL-188 cell-derived xenograft mice. Western blot results showed that protein levels of Notch1 and TGF-β were synergistically reduced by the combination, both in CL-188 cells and xenograft tumors. Tumor pathological analysis revealed that combined CUR and LUT synergistically increased necrosis, but the individual treatment with CUR and LUT had no significant effect on tumor necrosis. Therefore, combined curcumin and luteolin synergically inhibit colon cancer development by suppressing cell proliferation, necrosis, and migration associated with Notch1 and TGF-β pathways. This study provides evidence that colon cancer may be prevented/treated by consuming foods having high levels of luteolin and curcumin in humans.

The N&amp;P Co‐doped Lotus Root Derived Carbon Materials for Highly Sensitive Electrochemical Analysis of Baicalein and Luteolin

AbstractThe application of biomass‐based carbon materials in electrochemical sensing was limited due to their few active sites. So N and P double doped biomass pyrolytic carbon materials were designed in this paper. These gained materials were characterized by a series of characterization test techniques, and used as electrode modification to construct electrochemical sensors to detect baicalein (BA) and luteolin (LU). Under the best test condition, the minimum detectability of BA and LU was (7.8±0.25)×10−9 mol/L and (7.6±0.24)×10−9 mol/L (S/N=3), respectively. And the sensor performed well in the Shuanghuanglian oral liquid and the healthy human urine samples.

Low-dose dexamethasone in combination with luteolin improves myocardial infarction recovery by activating the antioxidative response

This study aimed to explore the effects of dexamethasone (DEX) and its combination with luteolin (LUT) on cardiac function during myocardial infarction (MI) in a mouse model. We evaluated whether the Keap1/Nrf2 pathway mediates the cardioprotective function of DEX both in vivo and in vitro. The MI mouse model was established by ligation of the left anterior descending coronary artery of wild-type (WT) and Nrf2 knockout mice. After recovery for 21 days, DEX or its combination with LUT was intraperitoneally administered at different doses to WT or Nrf2 knockout mice daily for 7 consecutive days. Mice treated with DEX at a low dose (50 μg/kg/day) showed better cardiac function, fewer cardiac lesions, and smaller infarct sizes compared with MI model mice. DEX (50 μg/kg/day) administration also significantly decreased the production of reactive oxygen species (ROS) and pro-inflammatory cytokines, increased the expression of antioxidative enzymes, and activated the Keap1/Nrf2/HO-1 pathway. However, in Nrf2 knockout mice, DEX treatment did not influence cardiac function, inflammation, the oxidative response, or Keap1/Nrf2/HO-1 activation. In the MI cell model, low concentrations of DEX attenuated the H2O2-induced decreases in cell viability and antioxidative enzyme levels and activated the Keap1/Nrf2/HO-1 pathway. Low doses of DEX exerted protective effects in MIR mice and MI cell models by improving cardiac function, eliminating ROS, inhibiting inflammatory responses, and activating antioxidative responses. The protective effects of DEX on myocardial tissues were mediated by the Keap1/Nrf2/HO-1 pathway.

Toxic effect of polyethylene microplastic on testicles and ameliorative effect of luteolin in adult rats: Environmental challenge

Polyethylene microplastic (PE-MP) is amongst the most manufactured plastics globally. However, emerging studies report its adverse effects on wildlife and humans. Luteolin (LUT) is a flavonoid compound known for its potent antioxidant properties. The present study was designed to estimate the toxic effect of PE-MP on testicles of adult male rats. The therapeutic potential of LUT was also determined in alleviating PE-MP instigated testicular dysfunctions. An experiment was carried on 48 adult male Sprague-Dawley rats, which were randomly classified into four groups: control, PE-MP (1.5 mg/kg), PE-MP + LUT (1.5 mg/kg + 50 mg/kg respectively), and LUT (50 mg/kg). The biochemical, spermatogenic, hormonal, and histopathological parameters were studied after 56 days of treatment. PE-MP exposure disrupted the biochemical profile by reducing catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione reductase (GSR) activities. In comparison, the concentration of reactive oxygen species (ROS) and malondialdehyde (MDA) levels were increased. PE-MP-intoxication also reduced the sperm motility, viability, the number of hypo-osmotic tails swelled spermatozoa, and epididymal sperm count; additionally, it increased the sperm morphological (head–tail and mid-piece) abnormalities. Furthermore, it lowered luteinizing hormone (LH), follicle-stimulating hormone (FSH), and plasma testosterone. PE-MP exposure led to histopathological damages in testicular tissues. However, LUT inverted all the illustrated impairments in testes. Our results demonstrate that PE-MP could cause testicular damage in male rats, effectively mitigated by LUT treatment.

Effect of covalent conjugation with chlorogenic acid and luteolin on allergenicity and functional properties of wheat gliadin

In order to develop hypoallergenic wheat products, this study investigated the reduction in allergenicity and improvement in functional properties of wheat gliadin (Gli) through covalent conjugation with chlorogenic acid (CA) and luteolin (LU), as well as the mechanism of covalent conjugation. The upward shifted of the electrophoresis band and the decrease of retention time of chromatographic peak suggested the molecular weight of Gli became larger, and the covalent conjugation was confirmed. Gli was covalently conjugated with CA/LU via the free amino, thiol and tyrosine groups. The grafting rate results showed the degree of covalent interaction between Gli and CA was greater than that of Gli-LU. The structure of Gli was altered distinctly after covalently conjugated with CA/LU, transforming to a more ordered structure. Western blot and ELISA analysis indicated that Gli-CA/LU conjugates showed the lower IgG binding capacity. Further, the thermal stability, antioxidant activity and in vitro digestibility of conjugates were significantly improved (p < 0.05). This research provided theoretical basis and guidance for the production of hypoallergenic wheat products.

Solubilization of luteolin in PVP40 solid dispersion improves inflammation-induced insulin resistance in mice

Our previous studies have confirmed that luteolin (LU) has a good therapeutic effect on obesity and its complications. However, due to its poor water solubility, the bioavailability is low with limited clinical application. Therefore, the water-soluble solid dispersions (SD) of luteolin were prepared with polyvinylpyrrolidone (PVP) (K10, K40 & K90) by solvent evaporation. The polyvinylpyrrolidone K40 (PVP40) was selected as the ideal carrier to formulate polyvinylpyrrolidone K40-luteolin solid dispersion (PVP40-LU SD), thereby the solubility of luteolin increased about 250 times compared to the pure luteolin, without changing its physical stability and activity. The crystallinity of luteolin was reduced after the formation of solid dispersion, and no strong drug-polymer interactions were observed. This prepared water-soluble luteolin inhibits the polarization of inflammatory macrophages by decreasing the expression of pro-inflammatory cytokine genes interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in vitro. Moreover, it can improve glucose tolerance and insulin sensitivity quickly after intraperitoneal injection in mice.