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.

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.

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.

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.

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.

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.

Effects of luteolin on chemical induced colon carcinogenesis in high fat diet-fed obese mouse / 한국영양학회지

PURPOSE: Colorectal cancer, which is one of the most commonly diagnosed cancers in developing and developed countries, is highly associated with obesity. The association is largely attributed to changes to western style diets in those countries containing high-fat and high-energy. Luteolin (LUT) is a known potent inhibitor of inflammation, obesity, and cancer. In this study, we investigated the effects of LUT on chemical-induced colon carcinogenesis in high fat diet (HFD)-fed obese mice. METHODS: Five-week-old male C57BL/6 mice received a single intraperitoneal injection of azoxymethane (AOM) at a dose of 12.5 mg/kg body weight. Mice were then divided into four groups (n = 10) that received one of the following diets for 11 weeks after the AOM injection: normal diet (ND); HFD; HFD with 0.0025% LUT (HFD LL); HFD with 0.005% LUT (HFD HL). One week after AOM injection, animals received 1~2% dextran sodium sulfate in their drinking water over three cycles consisting of five consecutive days each that were separated by 16 days. RESULTS: Body weight, ratio of colon weight/length, and tumor multiplicity increased significantly in the HFD group compared to the ND group. Luteolin supplementation of the HFD significantly reduced the ratio of colon weight/length and colon tumors, but not body weight. The levels of plasma TNF-α and colonic expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 protein increased in response to HFD, but were suppressed by LUT supplementation. Immunohistochemistry analysis also showed that iNOS expression was decreased by LUT. CONCLUSION: Consumption of LUT may reduce the risk of obesity-associated colorectal cancer by suppression of colonic inflammation.

Luteolin Induces Apoptosis via Mitochondrial Pathway and Inhibits Invasion and Migration of Oral Squamous Cell Carcinoma by Suppressing Epithelial-Mesenchymal Transition Induced Transcription Factors

Oral squamous cell carcinoma (OSCC) is the most common type of oral malignancy. Numerous therapies have been proposed for its cure. Research is continually being conducted to develop new forms of treatment as current therapies are associated with numerous side-effects. Luteolin, a common dietary flavonoid, has been demonstrated to possess strong anti-cancer activity against various human cancer cell lines. Nevertheless, research into luteolin-based anticancer activity against oral cancer remains scarce. Thus, the objective of this study was to assess the effect of luteolin as an anti-cancer agent. After treatment with luteolin, Ca9-22 and CAL-27 oral cancer cells showed condensed nuclei and enhanced apoptotic rate with evidence of mitochondria-mediated apoptosis. Epithelialmesenchymal transition (EMT) is closely related to tumor migration and invasion. Luteolin suppressed cancer cell invasion and migration in the current study. Elevated expression of E-cadherin, an adherens junction protein, was evident in both cell lines after luteolin treatment. Luteolin also significantly inhibited transcription factors (i.e., N-cadherin, Slug, Snail, Twist, and ZEB-1) that regulated expression of tumor suppressors such as E-cadherin based on Western blot analysis and quantitative PCR. Thus, luteolin could induce mitochondrial apoptosis and inhibit cancer cell invasion and migration by suppressing EMT-induced transcription factors.

Protective effect of luteolin on the transgenic Drosophila model of Parkinson's disease

In the present study we have studied the effect of 25, 50, 75 and 100 µM of luteolin on the transgenic Drosophila expressing human alpha synuclein. The doses of luteolin were established in diet and the PD flies were allowed to feed on it for 24 days. After 24 days of exposure the flies were assayed for climbing assay, oxidative stress markers, caspase-3 & 9 activity and dopamine content. The immunohistochemistry was also performed on the brain sections for the activity of tyrosine hydroxylase. The exposure of luteolin showed a dose dependent delay in the loss of climbing ability and activity, reduction in oxidative stress markers, caspase-3&9 activities and results in an increase in the dopamine content. The results obtained for the immunohistochemistry also supports the protective role of luteolin against the damage of the dopaminergic neurons

Combined treatment with myo-inositol and luteolin selectively suppresses growth of human lung cancer A549 cells possibly by suppressing activation of PDK1 and Akt / 南方医科大学学报

OBJECTIVE@#To study the effects of myo-inositol and luteolin on human lung cancer A549 cells and explore the possible mechanisms.@*METHODS@#A549 cells were treated with different concentrations of myo-inositol and luteolin, either alone or in combination, and the cell viability was examined using MTT assay. A549 cells and human bronchial epithelial Beas-2B cells were treated for 48 h with 10 mmol/L myo-inositol and 20 μmol/L luteolin, alone or in combination, and the cell proliferation was detected using MTT assay; the colony formation and migration of the cells were examined with colony formation assay and wound healing assay, respectively. The protein expression levels in A549 cells were detected using Western blotting.@*RESULTS@#Both myo-inositol and luteolin could dose-dependently inhibit the viability of A549 cells. Treatments with 10 mmol/L myo-inositol, 20 μmol/L luteolin, and both for 48 h caused significant reduction in the cell viability (92%, 83% and 70% of the control level, respectively) and colony number (79%, 73% and 43%, respectively), and significantly lowered the wound closure rate (24.61%, 13.08% and 8.65%, respectively, as compared with 29.99% in the control group). Similar treatments with myoinositol and luteolin alone or in combination produced no significant inhibitory effect on the growth, colony formation or migration of Beas-2B cells. The expressions of p-PDK1 and p-Akt in myo-inositol-treated A549 cells and the expression of pPDK1 in luteolin-treated cells were significantly decreased ( < 0.05), and the decrements were more obvious in the combined treatment group ( < 0.05).@*CONCLUSIONS@#Luteolin combined with myo-inositol can selectively inhibit the proliferation and migration of A549 cells, and these effects are probably mediated, at least in part, by suppressing the activation of PDK1 and Akt.

Cloning and expression analysis of and quantification of downstream products in under flooding stress / 中国中药杂志

To investigate the effects of the expression of flavonoid 3' hydroxylase gene ( and active ingredients in under flooding stress, we cloned F3'H from Hangju (temporarily named ) and conducted bioinformatics analysis. During the flower bud differentiation stage, we flooded the and then used the Real-time PCR to detect the relative expression of ; Finally, active ingredients of the inflorescence were measured by HPLC.The sequencing results showed that 1 562 bp sequence was acquired with the largest open reading frame of 1 527 bp, which encoded 508 amino acids. The phylogenetic tree found that was highly homologous to other species of Compositae. Real-time PCR results showed that had a significant response to flooding stress and had the highest expression level after flooding for 24 h, which was about 9 times as that of the control group. The results of HPLC showed that luteolin and luteoloside, the downstream products catalyzed by the F3'H, were significantly higher than those in the control group. It was also found that the contents of chlorogenic acid and 3,5- acid were also significantly higher than those of the control group. Therefore, regulates the synthesis of downstream products by regulating the expression of in the flavonoid synthesis pathway under flooding stress, thereby responding to flooding stress. The flooding stress during flower bud differentiation can significantly enhance the accumulation of active ingredients.