Luteolin suppresses oral carcinoma 3 (OC3) cell growth and migration via modulating polo-like kinase 1 (PLK1) expression and cellular energy metabolism / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Oral squamous cell carcinoma (OSCC) is a prevalent malignant tumor affecting the head and neck region (Leemans et al., 2018). It is often diagnosed at a later stage, leading to a poor prognosis (Muzaffar et al., 2021; Li et al., 2023). Despite advances in OSCC treatment, the overall 5-year survival rate of OSCC patients remains alarmingly low, falling below 50% (Jehn et al., 2019; Johnson et al., 2020). According to statistics, only 50% of patients with oral cancer can be treated with surgery. Once discovered, it is more frequently at an advanced stage. In addition, owing to the aggressively invasive and metastatic characteristics of OSCC, most patients die within one year of diagnosis. Hence, the pursuit of novel therapeutic drugs and treatments to improve the response of oral cancer to medication, along with a deeper understanding of their effects, remains crucial objectives in oral cancer research (Johnson et al., 2020; Bhat et al., 2021; Chen et al., 2023; Ruffin et al., 2023).

Active Ingredients of Reduning Injection Maintain High Potency against SARS-CoV-2 Variants / 中国结合医学杂志

OBJECTIVE@#To investigate the anti-coronavirus potential and the corresponding mechanisms of the two ingredients of Reduning Injection: quercetin and luteolin.@*METHODS@#A pseudovirus system was designed to test the efficacy of quercetin and luteolin to inhibit SARS-CoV-2 infection and the corresponding cellular toxicity. Luteolin was tested for its activities against the pseudoviruses of SARS-CoV-2 and its variants. Virtual screening was performed to predict the binding sites by Autodock Vina 1.1.230 and PyMol. To validate docking results, surface plasmon resonance (SPR) was used to measure the binding affinity of the compounds with various proteins of the coronaviruses. Quercetin and luteolin were further tested for their inhibitory effects on other coronaviruses by indirect immunofluorescence assay on rhabdomyosarcoma cells infected with HCoV-OC43.@*RESULTS@#The inhibition of SARS-CoV-2 pseudovirus by luteolin and quercetin were strongly dose-dependent, with concentration for 50% of maximal effect (EC50) of 8.817 and 52.98 µmol/L, respectively. Their cytotoxicity to BHK21-hACE2 were 177.6 and 405.1 µmol/L, respectively. In addition, luetolin significantly blocked the entry of 4 pseudoviruses of SARS-CoV-2 variants, with EC50 lower than 7 µmol/L. Virtual screening and SPR confirmed that luteolin binds to the S-proteins and quercetin binds to the active center of the 3CLpro, PLpro, and helicase proteins. Quercetin and luteolin showed over 99% inhibition against HCoV-OC43.@*CONCLUSIONS@#The mechanisms were revealed of quercetin and luteolin inhibiting the infection of SARS-CoV-2 and its variants. Reduning Injection is a promising drug for COVID-19.

Comprehensive identification of metabolites and metabolic characteristics of luteolin and kaempferol in Simiao Yong'an Decoction in rats by UHPLC-LTQ-Orbitrap MS/MS / 中国中药杂志

Simiao Yong'an Decoction is a classic prescription for treating gangrene. Modern medical evidence has proven that Si-miao Yong'an Decoction has therapeutic effects on atherosclerosis(AS), vascular occlusion angeitides, and hypertension, while its pharmacodynamic mechanism remains unclear. The evidence of network pharmacology, molecular docking, literature review, and our previous study suggests that luteolin and kaempferol are two major flavonoids in Simiao Yong'an Decoction and can inhibit macrophage inflammation and exert anti-AS effects. However, due to lack of the metabolism studies in vivo, little is known about the metabolic characteristics of luteolin and kaempferol. This study employed ultra-performance liquid chromatography coupled with linear ion trap-Orbitrap mass spectrometry(UHPLC-LTQ-Orbitrap MS/MS) and relevant software to identify the metabolites and metabolic pathways of luteolin and kaempferol in rat plasma, urine, and feces, after oral administration of luteolin and kaempferol, respectively. After the administration of luteolin, 10, 11, and 3 metabolites of luteolin were detected in the plasma, urine, and feces, respectively. After the administration of kaempferol, 9, 3, and 1 metabolites of kaempferol were detected in the plasma, urine, and feces, respectively. The metabolic pathways mainly involved methylation, glucuronidation, and sulfation. This study enriches the knowledge about the pharmacological mechanism of luteolin and kaempferol and supplies a reference for revealing the metabolic process of other flavonoids in Simiao Yong'an Decoction, which is of great significance for elucidating the pharmacological effects and effective substances of this decoction in vivo.

A new norsesquiterpenoid from Arctium lappa leaves / 中国中药杂志

Chemical constituents were isolated and purified from ethyl acetate fraction of Arctium lappa leaves by silica gel, ODS, MCI, and Sephadex LH-20 column chromatography. Their structures were identified with multiple spectroscopical methods including NMR, MS, IR, UV, and X-ray diffraction combined with literature data. Twenty compounds(1-20) were identified and their structures were determined as arctanol(1), citroside A(2), melitensin 15-O-β-D-glucoside(3), 11β,13-dihydroonopordopicrin(4), 11β,13-dihydrosalonitenolide(5), 8α-hydroxy-β-eudesmol(6), syringin(7), dihydrosyringin(8), 3,4,3',4'-tetrahydroxy-δ-truxinate(9),(+)-pinoresinol(10), phillygenin(11), syringaresinol(12), kaeperferol(13), quercetin(14), luteolin(15), hyperin(16), 4,5-O-dicaffeoylquinic acid(17), 1H-indole-3-carboxaldehyde(18), benzyl-β-D-glucopyranoside(19), and N-(2'-phenylethyl) isobutyramide(20). Among them, compound 1 is a new norsesquiterpenoid, and compounds 2-5, 7-8, and 18-20 are isolated from this plant for the first time.

Luteoloside protects the vascular endothelium against iron overload injury via the ROS/ADMA/DDAH II/eNOS/NO pathway / 中国天然药物

Iron overload injury is considered to be a part of blood stasis syndrome of arthralgia in traditional Chinese medicine. Its primary therapies include clearing heat and detoxification, activating blood circulation, and removing blood stasis. Lonicera japonica flos (LJF) has long been known as an excellent antipyretic and antidote. Luteoloside (Lut) is one of the main components of LJF and exhibits antioxidant, anti-inflammatory, and cytoprotective properties. However, the protection of Lut against iron overload injury and its underlying mechanisms remain unclear. Therefore, HUVECs were exposed to 50 μmol·L-1 iron dextran for 48 h to establish an iron overload damage model and the effects of Lut were assessed. Our results showed that 20 μmol·L-1 Lut not only increased cell viability and weakened LDH activity, but also significantly up-regulated DDAHⅡ expression and activity, increased p-eNOS/eNOS ratio and NO content, and reduced ADMA content in HUVECs exposed to iron overload. Furthermore, Lut significantly attenuated intracellular/mitochondrial ROS generation, improved SOD, CAT, and GSH-Px activities, reduced MDA content, maintained MMP, inhibited mPTP opening, prevented cyt c from mitochondria released into cytoplasm, reduced cleaved-caspase3 expression, and ultimately decreased cell apoptosis induced by iron overload. The effects of Lut were similar to those of L-arginine (an ADMA competitive substrate), cyclosporin A (a mPTP blocker agent), and edaravone (a free radical scavenger) as positive controls. However, addition of pAD/DDAH II-shRNA adenovirus reversed the above beneficial effects of Lut. In conclusion, Lut can protect HUVECs against iron overload injury via the ROS/ADMA/DDAH II/eNOS/NO pathway. The mitochondria are the target organelles of Lut's protective effects.

Screening of effective antioxidant components from Trichosanthes extract and assessment of their antioxidant activity / 南方医科大学学报

OBJECTIVE@#To screen the effective antioxidant components in Trichosanthes extract based on the mean value of Deng's correlation degree and assess the antioxidant activity of the identified components.@*METHOD@#High-performance liquid chromatography (HPLC) was used to obtain the fingerprints of Trichosanthes extract, and the clearance rates of DPPH · and O2-· by 3, 9 and 27 mg/mL Trichosanthes extract were determined. The antioxidant spectrum effect of Trichosanthes extract was analyzed by calculating the mean value of Deng's correlation degree to screen the effective antioxidant component group. According to the contents of each known components in the antioxidant effective component group, mixed solutions of the components were prepared and tested for their clearance rates of DPPH · and O2-·.@*RESULTS@#The 36 common peaks in HPLC fingerprints of Trichosanthes extract showed different degrees of correlation with DPPH · and O2-· clearance. The common peaks with a correlation degree greater than the median value included peaks 21, 36, 8, 31, 14, 5, 27, 2, 24, 15, 18, 33, 22, 34, 35, 19, 28 and 25. The 5 components, namely kaempferol (peak 36), isoquercitrin (peak 8), luteolin (peak 31), rutin (peak 5) and apigenin (peak 35), were tentatively identified to constitute the effective antioxidant component group with a mass ratio 3∶2∶2∶ 1∶1 in Trichosanthes extract. The prepared mixed solutions of antioxidant effective component group (6.12, 2.04, and 0.68 μg/mL) showed clearance rates of DPPH · of 65.4%, 64.0% and 61.0%, and clearance rates of O2-· of 12.9%, 9.5% and 8.3%, respectively.@*CONCLUSION@#We identified the material basis for the antioxidant activity of Trichosanthes and screened the antioxidant effective component group in Trichosanthes extract.

Isomeric discrimination of kaempferol versus luteolin by online energy-resolved mass spectrometry / 中国中药杂志

Isomers are widely distributed in Chinese herbal medicines,and can be discriminated by energy-resolved mass spectrometry( ER-MS). However,ER-MS was performed through direct injection of reference compounds with syringe pump,which encountered a significant technical barrier for high-throughput and automated measurements. Herein,online ER-MS was conducted using LC-MS platform,and a pair of isomers,kaempferol vs luteolin,were employed as a case study to illustrate and assess the utility of online ER-MS for isomeric discrimination. High-resolution tandem mass spectrometry data of both flavonoids were acquired on LC-QE-Orbitrap-MS,and the fragmentation pathways responsible for the primary fragment ions were proposed. The primary signal in MS1 occurred at m/z 285( [M-H]-),and the primary signals of either compound generated by retro-Diels-Alder fragmentation were observed at m/z 151 and 133. The spectral information was subsequently transferred onto LC-Qtrap-MS platform to carry out online ER-MS. Two precursor-to-product ion transition candidates were constructed as m/z 285>151 and 285>133,and either afterward derived a set of pseudo-ion transitions( PITs) and so forth,exactly corresponding to a series of progressive collision energies( eg-5,-8,-11 e V,and so on). All PITs were typed into the monitoring list of multiple reaction monitoring program to generate the peak area datasets. Either dataset was normalized using the highest values in the set and imported into Graph Pad Prism software to plot the Gaus-sian-shaped curve that was termed as the break-down graph. The apex of the regressive curve was termed as optimal collision energy( OCE). The OCE values corresponding to m/z 285>151 were calculated as-29. 06 e V and-35. 71 e V for kaempferol and luteolin,respectively. In the case of m/z 285>133,the OCEs were yielded as-44. 15 e V for kaempferol and-49. 01 e V for luteolin. With re-ference to their chemical structures,the location of hydroxyl group was regarded to be responsible for the differences of either m/z 285>151 or 285>133 between the isomers,attributing to their different bond properties. Above all,online ER-MS offers an eligible tool for isomeric discrimination,and provides meaningful information for the accurate chemical composition characterization based on LC-MS,which is not limited to Chinese herbal medicines.

Molecular mechanism of luteolin regulating lipoxygenase pathway against oxygen-glucose deprivation/reperfusion injury in H9c2 cardiomyocytes based on molecular docking / 中国中药杂志

The aim of this study was to investigate the mechanism of luteolin regulating lipoxygenase pathway against oxygen-glucose deprivation/reperfusion(OGD/R) injury in H9 c2 cardiomyocytes. First, Discovery Studio 2019 was used for the molecular docking of luteolin with three key enzymes including lipoxygenase 5(ALOX5), lipoxygenase 12(ALOX12), and lipoxygenase 15(ALOX15) in lipoxygenase pathway. The docking results showed that luteolin had high docking score and similar functional groups with the original ligand. From this, H9 c2 cardiomyocytes were cultured in vitro, and then the injury model of H9 c2 cardiomyocytes was induced by deprivation of oxygen-glucose for 8 h, and rehabilitation of oxygen-glucose for 12 h. Cell viability was detected by tetrazolium(MTT) colorimetry. H9 c2 cardiomyocytes were observed with a fluorescence inverted microscope, and colorimetry was used to detect the level of lactate dehydrogenase(LDH) in cell supernatant. The results showed that luteolin could significantly protect the morphology of H9 c2 cells, significantly improve the survival rate of H9 c2 cardiomyocytes in OGD/R injury model, reduce the level of LDH in cell supernatant, inhibit cytotoxicity, and maintain the integrity of cell membrane. The inflammatory cytokines interleukin-6(IL-6) and tumor necrosis factor-α(TNF-α) were detected by enzyme-linked immunosorbent assay. Compared with the model group, luteolin can significantly reduce the release of IL-6 and TNF-α. Western blot was employed to detect the protein levels of ALOX5, ALOX12, and ALOX15 in lipoxygenase pathway. After luteolin intervention, the protein levels of ALOX5, ALOX12, and ALOX15 were significantly down-regulated compared with those in model group. These results indicate that luteolin can inhibit the release of IL-6 and TNF-α by restraining the activation of lipoxygenase pathway, thereby playing a protective role in the cardiomyocyte injury model induced by OGD/R.

Luteolin reverses OPCML methylation to inhibit proliferation of breast cancer MDA-MB-231 cells / 南方医科大学学报

OBJECTIVE@#To observe the effect of luteolin on the proliferation and expression of OPCML in breast cancer cell line MDA-MB-231.@*METHODS@#Cultured MDA-MB-231 cells were treated with luteolin at the concentrations of 5, 10 and 20 μmol/L for 24 or 48 h. MTT assay was used to detect cell proliferation and flow cytometry was used to detect the cell apoptosis. The expressions of OPCML mRNA and protein were detected using real-time quantitative PCR and Western blotting, respectively. OPCML gene methylation in the promoter region was detected using methylation-specific PCR (MSP), and the activity of methylase in the cells was analyzed.@*RESULTS@#MTT assay showed that treatment with luteolin at 5, 10 and 20 μmol/L for 24 h concentration-dependently decreased the viability of MDA-MB-231 cells ( < 0.05). Flow cytometry also showed that luteolin at different concentrations could induce apoptosis of MDA-MB-231 cells ( < 0.05). Luteolin dose-dependently induced the expression of OPCML mRNA and protein in MDA-MB-231 cells ( < 0.05), down-regulated the methylation status in the promoter region of OPCML gene, up-regulated the level of non-methylated OPCML, and reduced the activity of methylase in the cells ( < 0.05).@*CONCLUSIONS@#Luteolin inhibits the proliferation of MDA-MB-231 breast cancer cells probably by upregulating OPCML expression and its demethylation.

Effect of Luteolin on Biochemical, Immunohistochemical, and Morphometrical Changes in Rat Spinal Cord following Exposure to a 900 MHz Electromagnetic Field / 生物医学与环境科学（英文）

Objective@#This study aimed to investigate the effect of exposure to a 900 MHz electromagnetic field (EMF) on the cervical spinal cord (CSC) of rats and the possible protective effect of luteolin (LUT) against CSC tissue damage.@*Methods@#Quantitative data were obtained stereological, biochemical, immunohistochemical, and histopathological techniques. We investigated morphometric value, superoxide dismutase (SOD) level, and the expression of high-mobility group box 1 protein molecules, as well as histological changes.@*Results@#The total number of motor neurons in the EMF group significantly decreased in comparison with that in the control group ( < 0.05). In the EMF + LUT group, we found a significant increase in the total number of motor neurons compared with that in the EMF group ( < 0.05). SOD enzyme activity in the EMF group significantly increased in comparison with that in the control group ( < 0.05). By contrast, the EMF+LUT group exhibited a decrease in SOD level compared with the EMF group ( < 0.05).@*Conclusion@#Our results suggested that exposure to EMF could be deleterious to CSC tissues. Furthermore, the protective efficacy of LUT against SC damage might have resulted from the alleviation of oxidative stress caused by EMF.

The effects of luteolin nanoparticles on the healing of extracted tooth socket in rabbits

Objective: To evaluate the effects of luteolin nanoparticles on the process tooth socket healing in rabbits. Design: This study comprised five rabbits randomly assigned to control animal and experimental animals. Immediately after the extraction of an upper maxillary incisor, the alveolar sockets of experimental animals were treated with topical luteolin while alveolar sockets of the control group remained without treatment. The animals were sacrificed by decapitation with deep anesthesia seven days post tooth extraction. The tooth sockets were sectioned and stained with hematoxylin and eosin stains. Results: Histological evaluation revealed that luteolin treatment induced earlier healing of extracted tooth sockets. Conclusion: These findings suggest that luteolin accelerates the healing process in tooth sockets of rabbits.

Adsorption/desorption characteristics and enrichment of quercetin, luteolin and apigenin from Flos populi using macroporous resin

Abstract In this study, the adsorption/desorption characteristics of quercetin, luteolin and apigenin from Flos populi extract (Populus tomentosa Carrière, Salicaceae) on twelve macroporous resins (NKA-9, HPD-600, HPD-826, HPD-750, HPD-400, DM-130, AB-8, SP-825, X-5, D-101, HPD-100, HPD-200) were evaluated. Both high adsorption and desorption capacities of quercetin, luteolin and apigenin from Flos populi extract on SP-825 resin indicated that SP-825 resin was appropriate and its data were well fitted to the Langmuir and Freundlich isotherms. To get the optimal separation process, the influences of factors such as flow rates, loading sample volumes, concentrations of desorption solution were further investigated. Column packed with SP-825 resin was used to perform dynamic adsorption and desorption experiments. After one round of treatment, the contents of quercetin, luteolin and apigenin in the final products were 3.75-fold, 3.67-fold and 3.54-fold increased with recovery yields of 87.25, 85.19 and 82.22%, respectively. The results showed that the preparative enrichment of quercetin, luteolin and apigenin was available via adsorption and desorption on SP-825 resin. This method is a promising basis for the large-scale preparation of quercetin, luteolin and apigenin from Flos populi.

Effects of different temperature stress on cell membrane permeability,active oxygen metabolism and accumulation of effective substances in Lonicera japonicea / 中国中药杂志

The study is aimed to explore the effects of stress at different temperatures( 35,45,55 ℃) on membrane permeability,active oxygen metabolism and accumulation of effective substances in Lonicera japonica,and provide theoretical basis for reducing deterioration and revealing browning mechanism during postharvest processing of L. japonica. The cell membrane permeability( relative conductivity,MDA content),active oxygen metabolism( SOD,POD,PPO,CAT activity) and the accumulation of effective substances( chlorogenic acid,luteolin,neochlorogenic acid,cryptochlorogenic acid,3,5-dicaffeoylquinic acid,3,4-dicaffeoylquinic acid and 4,5-dicaffeoylquinic acid) of L. japonica were all studied by constant temperature drying method,and the results were analyzed by the SPSS 17. 0 statistical software. The results showed that MDA content in L. japonica was increased by 151. 14% at 35 ℃,SOD,POD,PPO and CAT activity were 29. 73%,42. 86%,105. 02% and 10. 74% higher than at 45 ℃,respectively. The order of effective substance content in L. japonica was 35 ℃ >45 ℃ >55 ℃. The changes of membrane permeability,activity of active oxygen metabolizing enzyme and accumulation of active components were significantly affected by different temperature stress. The indexes showed that physiological and active oxygen metabolizing enzyme activity of L. japonica was the highest under 35 ℃ stress,chlorogenic acid and luteolin were effectively accumulated,which provides basic data for solving browning problem in the postharvest processing of L. japonica.

Chemical constituents of Cassia siamea / 中国中药杂志

A total of ten compounds were isolated from the 90% Et OH extract of Cassia siamea by using various chormatographic techniques,and their structures were established as( 2' S)-2-( propan-2'-ol)-5,7-dihydroxy-benzopyran-4-one( 1),chrobisiamone( 2), 2-( 2'-hydroxypropyl)-5-methyl-7-hydroxychromone( 3), 2,5-dimethyl-7-hydroxychromone( 4), 2-methyl-5-acetonyl-7-hydroxychromone( 5),3-O-methylquercetin( 6),3,5,7,3',4'-pentahydroxyflavonone( 7),luteolin-5,3'-dimethylether( 8),4-( trans)-acetul-3,6,8-trihydroxy-3-methyl-dihydronapht halenone( 9) and 6-hydroxymellein( 10) based on the spectroscopic data.Compound 1 was a new compound,and 3,4,6,8 were isolated from this plant for the first time.

Establishment of HPLC fingerprint and comparison of active ingredients between varieties of chrysanthemum in Hubei province / 中国中药杂志

In this paper,the fingerprint of different varieties of chrysanthemum were established with " Similarity Evaluation System for Chromatographic Fingerprint of Chinese Materia Medica" and the content of chlorogenic acid,galuteolin and 3,5-O-dicaffeoylquinic acid in 29 batches of different varieties of chrysanthemum in Futianhe town,Huangtugang town and Wuhan city were compared. At the same time,similarity evaluation and common peak clustering analysis were carried out. There were 11 common peaks in the fingerprints of 29 batches of different varieties of chrysanthemum,and the similarity ranged from 0. 802 to 0. 975. Hangju and Gongju were divided into one group by cluster analysis,and Huangju into another category. The established fingerprint method provides a basis for the identification of chrysanthemum cultivars. The content of 29 batches of chlorogenic acid was between 4. 092 and 11. 723 mg·g-1,luteolin was between 1. 010 and 11. 713 mg·g-1,and 3,5-O-dicaffeoylquinic acid was between 8. 828 and 33. 435 mg·g-1,both reach the pharmacopoeia standard,but the effective components of different varieties of chrysanthemum were quite different. Based on the contents of three active ingredients and the diversity of fingerprint peaks,the quality of the characteristic germplasm resource of local Fubaijuin Macheng is superior,and the protection of local characteristic germplasm resource should be strengthened in production.

Isolation and Quantitative Analysis of BACE1 Inhibitory Compounds from Cirsium maackii Flower

The purpose of our study was to evaluate anti-AD potential of Cirsium maackii flowers. MeOH extract, CH2Cl2, EtOAc, and n-BuOH fraction of this flower notably inhibited BACE1 (IC₅₀ = 76.47 ± 1.66, 22.98 ± 1.45, 8.65 ± 0.63, and 72.47 ± 3.04 µg/mL, respectively). β-amyrenone (49.70 mg) (1), lupeol acetate (1.43 g) (2), lupeol (1.22 g) (3), lupenone (23.70 mg) (4), β-sitosterol (1.01 g) (6), and β-sitosterol glucoside (13.00 mg) (7) from CH₂Cl₂, apigenin (100.20 mg) (8), luteolin (19.00 mg) (9), apigenin 7-O-glucuronide methyl ester (21.30 mg) (14), and tracheloside (53.70 mg) (5) from EtOAc, apigenin 5-O-glucoside (11.00 mg) (10), luteolin 5-O-glucoside (11.00 mg) (11) and apigenin 7-O-glucuronide (91.00 mg) (12) from n-BuOH, and luteolin 7-O-glucuronide (22.00 mg) (13) from H₂O fraction were isolated. HPLC showed high levels of 8, 9 and 12 in MeOH extract (33.07 ± 0.07, 31. 44 ± 0.17 and 16.89 ± 0.33 mg/g, respectively), EtOAc (161.01 ± 1.78, 96.93 ± 0.34 and 73.38 ± 0.06 mg/g, respectively), and n-BuOH fraction (32.18 ± 0.33, 44.31 ± 0.32 and 105.94 ± 0.36 mg/g, respectively). Since, 3 and 9 are well-known BACE1 inhibitors, the anti-AD activity of C. maackii flower might be attributable to their presence.

Sleep Promoting Effect of Luteolin in Mice via Adenosine A1 and A2A Receptors

Luteolin, a widespread flavonoid, has been known to have neuroprotective activity against various neurologic diseases such as epilepsy, and Alzheimer’s disease. However, little information is available regarding the hypnotic effect of luteolin. In this study, we evaluated the hypnotic effect of luteolin and its underlying mechanism. In pentobarbital-induced sleeping mice model, luteolin (1, and 3 mg/kg, p.o.) decreased sleep latency and increased the total sleep time. Through electroencephalogram (EEG) and electromyogram (EMG) recording, we demonstrated that luteolin increased non-rapid eye movement (NREM) sleep time and decreased wake time. To evaluate the underlying mechanism, we examined the effects of various pharmacological antagonists on the hypnotic effect of luteolin. The hypnotic effect of 3 mg/kg of luteolin was not affected by flumazenil, a GABAA receptor-benzodiazepine (GABAAR-BDZ) binding site antagonist, and bicuculine, a GABAAR-GABA binding site antagonist. On the other hand, the hypnotic effect of 3 mg/kg of luteolin was almost completely blocked by caffeine, an antagonist for both adenosine A1 and A2A receptor (A1R and A2AR), 8-Cyclopentyl-1,3-dipropylxanthine (DPCPX), an A1R antagonist, and SCH-58261, an A2AR antagonist. From the binding affinity assay, we have found that luteolin significantly binds to not only A1R but also A2AR with IC₅₀ of 1.19, 0.84 μg/kg, respectively. However, luteolin did not bind to either BDZ-receptor or GABAAR. From these results, it has been suggested that luteolin has hypnotic efficacy through A1R and A2AR binding.

Luteolin and luteolin-7-O-glucoside protect against acute liver injury through regulation of inflammatory mediators and antioxidative enzymes in GalN/LPS-induced hepatitic ICR mice

BACKGROUND/OBJECTIVES: Anti-inflammatory and antioxidative activities of luteolin and luteolin-7-O-glucoside were compared in galactosamine (GalN)/lipopolysaccharide (LPS)-induced hepatitic ICR mice. MATERIALS/METHODS: Male ICR mice (6 weeks old) were divided into 4 groups: normal control, GalN/LPS, luteolin, and luteolin-7-O-glucoside groups. The latter two groups were administered luteolin or luteolin-7-O-glucoside (50 mg/kg BW) daily by gavage for 3 weeks after which hepatitis was induced by intraperitoneal injection of GalN and LPS (1 g/kg BW and 10 µg/kg BW, respectively). RESULTS: GalN/LPS produced acute hepatic injury by a sharp increase in serum AST, ALT, and TNF-α levels, increases that were ameliorated in the experimental groups. In addition, markedly increased expressions of cyclooxygenase (COX)-2 and its transcription factors, nuclear factor (NF)-κB and activator protein (AP)-1, were also significantly attenuated in the experimental groups. Compared to luteolin-7-O-glucoside, luteolin more potently ameliorated the levels of inflammatory mediators. Phase II enzymes levels and NF-E2 p45-related factor (Nrf)-2 activation that were decreased by GalN/LPS were increased by luteolin and luteolin-7-O-glucoside administration. In addition, compared to luteolin, luteolin-7-O-glucoside acted as a more potent inducer of changes in phase II enzymes. Liver histopathology results were consistent with the mediator and enzyme results. CONCLUSION: Luteolin and luteolin-7-O-glucoside protect against GalN/LPS-induced hepatotoxicity through the regulation of inflammatory mediators and phase II enzymes.

Gastroprotective and antioxidant effects of Eremurus spectabilis Bieb. methanol extract and its isolated component isoorientin on indomethacin induced gastric ulcers in rats

Abstract Purpose: To investigate the gastroprotective effect of methanol extract of E. spectabilis and its major component isoorientin. Methods: Effects of isoorientin and methanol extract of E. spectabilis were investigated in indomethacin-induced gastric damage model on rats. Famotidine was used as the standard antiulcer drug. Numerical density of ulcer areas and oxidative status were determined on stomach tissues of rats. Results: All doses of isoorientin and methanol extract decreased MDA level and increased SOD activity and GSH levels in the stomach tissue of rats. When numerical density of ulcer areas were analized, the 500 mg/kg dose of methanol extract (84%) exhibited a similar effect to 20 mg/kg dose of standart drug famotidine (87%). Conclusions: The gastroprotective effects of E. spectabilis and its major constituent isoorientin in rats for the first time. Detailed analyses suggested that potential antioxidant activity of both plant extract and isoorientin mediates the gastroprotective effect.

Phytochemical Constituents of Capsella bursa-pastoris and Their Anti-inflammatory Activity

Phytochemical investigation of 80% MeOH extract of the aerial parts of Capsella bursa-pastoris yielded fourteen compounds (1 – 14). The structures of the compounds were elucidated by spectroscopic methods to be methyl-1-thio-β-D-glucopyranosyl disulfide (1), 10-methylsulphinyl-decanenitrile (2), 11-methyl-sulphinyl-undecanenitrile (3), 1-O-(lauroyl)glycerol (4), phytene-1, 2-diol (5), (3S,5R,6S,7E)-5,6-epoxy-3-hydroxy-7-megastigmen-9-one (6), loliolide (7), β-sitosterol (8), 3-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-1-propanone (9), 1-feruloyl-β-D-glucopyranoside (10), pinoresinol-4′-O-β-D-glucopyranoside (11), luteolin (12), quercetin-3-O-β-D-glucopyranoside (13), and luteolin 6-C-β-glucopyranoside (14). Although compound 1 was reported as synthetic compound, 1 was first isolated from natural source. NMR spectral data assignments of 1, 2 and 3 were reported for the first time, and compounds 1 – 14 were for the first time reported from this plant source. The anti-inflammatory effects of 1 – 14 were evaluated in lipopolysaccharide (LPS)-stimulated murine microglia BV-2 cells. Compounds 12 exhibited strong inhibitory effects on nitric oxide production in LPS-activated BV-2 cells with IC50 values of 9.70 µM.