Luteolin ameliorates loperamide-induced functional constipation in mice

Functional constipation (FC) is one of the most common gastrointestinal disorders characterized by hard stools and infrequent bowel movements, which is associated with dysfunction of the enteric nervous system and intestinal motility. Luteolin, a naturally occurring flavone, was reported to possess potential pharmacological activities on intestinal inflammation and nerve injury. This study aimed to explore the role of luteolin and its functional mechanism in loperamide-induced FC mice. Our results showed that luteolin treatment reversed the reduction in defecation frequency, fecal water content, and intestinal transit ratio, and the elevation in transit time of FC models. Consistently, luteolin increased the thickness of the muscular layer and lessened colonic histopathological injury induced by loperamide. Furthermore, we revealed that luteolin treatment increased the expression of neuronal protein HuC/D and the levels of intestinal motility-related biomarkers, including substance P (SP), vasoactive intestinal polypeptide (VIP), and acetylcholine (ACh), as well as interstitial cells of Cajal (ICC) biomarker KIT proto-oncogene, receptor tyrosine kinase (C-Kit), and anoctamin-1 (ANO1), implying that luteolin mediated enhancement of colonic function and contributed to the anti-intestinal dysmotility against loperamide-induced FC. Additionally, luteolin decreased the upregulation of aquaporin (AQP)-3, AQP-4, and AQP-8 in the colon of FC mice. In summary, our data showed that luteolin might be an attractive option for developing FC-relieving medications.

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.

Protective effect of luteolin on acute lung injury induced by extracorporeal circulation and its mechanism / 中国胸心血管外科临床杂志

@#Objective    To investigate the protective effect of atomized inhalation of nano-luteolin preparation on acute lung injury caused by extracorporeal circulation, and to explore the anti-inflammatory mechanism of luteolin, so as to provide study basis for clinical application. Methods    Thirty male SD rats aged 5-6 weeks and weighting 160-190 g, were randomly divided into a preoperative baseline (BL) group, arteriovenous partial diversion (ECC) group, luteolin atomization pretreatment for 1 h group, 2 h group, and 3 h group by random number method, with 6 rats in each group. In the BL group, lung tissue samples were collected directly without any treatment. The ECC group received mechanical ventilation, and the whole body was heparinized after the jugular arteriovenous intubation. The flow was transferred for 30 minutes, followed by observation for 60 minutes, then lung tissue samples were collected. Subjects in the 1 h, 2 h and 3 h groups were placed in a small animal atomizer 1 h, 2 h and 3 h before flow transfer respectively, and the subsequent operation was the same as that in the ECC group. The inflammatory level of lung tissue was detected to evaluate the degree of pathological injury of lung tissue. Western blotting (WB) was used to detect the contents of p65, IKKα, IKKβ and IKKγ in the cytoplasm of lung tissue samples of each group. Results    Compared with the ECC group, the levels of IL-6 and TNF-α in lung tissues and the degree of pathological injury in the 1 h, 2 h and 3 h groups decreased, and the difference between the 3 h group and the ECC group was statistically different (P<0.05). WB results showed that compared with the ECC group, the levels of p65 in lung tissue of the 1 h, 2 h and 3 h groups decreased; the levels of IKKβ in the lung tissue increased in the 1 h, 2 h and 3 h groups, and the difference of the 3 h group was statistically different from the ECC group (P<0.05). Conclusion    Luteolin has a protective effect on acute lung injury induced by ECC, and atomization 3 h in advance has the best protective effect on lung. The mechanism plays a protective role in ECC-induced acute lung injury, may be through inhibition of IKKβ phosphorylation, thereby inhibiting the classical NF-κB signaling pathway.

Discovery of the radio-protecting effect of Ecliptae Herba, its constituents and targeting p53-mediated apoptosis in vitro and in vivo

Radiation protection drugs are often accompanied by toxicity, even amifostine, which has been the dominant radio-protecting drug for nearly 30 years. Furthermore, there is no therapeutic drug for radiation-induced intestinal injury (RIII). This paper intends to find a safe and effective radio-protecting ingredient from natural sources. The radio-protecting effect of Ecliptae Herba (EHE) was discovered preliminarily by antioxidant experiments and the mouse survival rate after 137Cs irradiation. EHE components and blood substances in vivo were identified through UPLC‒Q-TOF. The correlation network of "natural components in EHE-constituents migrating to blood-targets-pathways" was established to predict the active components and pathways. The binding force between potential active components and targets was studied by molecular docking, and the mechanism was further analyzed by Western blotting, cellular thermal shift assay (CETSA), and ChIP. Additionally, the expression levels of Lgr5, Axin2, Ki67, lysozyme, caspase-3, caspase-8,8-OHdG, and p53 in the small intestine of mice were detected. It was found for the first time that EHE is active in radiation protection and that luteolin is the material basis of this protection. Luteolin is a promising candidate for RⅢ. Luteolin can inhibit the p53 signaling pathway and regulate the BAX/BCL2 ratio in the process of apoptosis. Luteolin could also regulate the expression of multitarget proteins related to the same cell cycle.

Study on the effects and mechanism of luteolin on osteogenic repair of bone defects / 中国药房

OBJECTIVE To investigate the effects and mechanism of luteolin on osteogenic repair of bone defects. METHODS The targets and potential pathways of luteolin in the treatment of bone defects were screened by network pharmacology method， and then the top 2 targets were selected by Hub gene screening for molecular docking verification， with binding energy as the evaluation standard. In vitro experiments were conducted on rat bone mesenchymal stem cells （BMSC） and rat umbilical vein endothelial cells （RUVEC）. Phenotypic validation was performed using alkaline phosphatase staining， alizarin red S staining， and in vitro angiogenesis experiments. Western blot assay was used to detect the protein expressions of phosphatidylinositol 3 kinase （PI3K） and protein kinase 1 （Akt1）， so as to validate the mechanism of luteolin on osteogenic differentiation of BMSC and angiogenesis of RUVEC in vitro. RESULTS The results of network pharmacology showed that the effects of luteolin on vascular formation and bone repair in bone defects were mainly related to Akt1， SRC， estrogen receptor 1， epidermal growth factor receptor， cyclooxygenase 2， matrix metalloproteinase 9 targets， and were closely related to PI3K-Akt signaling pathway. The results of molecular docking showed that luteolin binding to Akt1 and SRC proteins was stable. The results of in vitro experiments showed that luteolin could significantly improve the expressions and activities of alkaline phosphatase in BMSC， increased the number of calcium salt deposits and calcified nodules， and promoted calcification of BMSC. Compared with luteolin 0 μmol/L group， the angiogenesis ability of RUVEC was enhanced significantly in luteolin 1， 10 μmol/L groups， the length of blood vessels and the protein expressions of PI3K and Akt1 were significantly increased （P＜0.05 or P＜0.01）； the higherthe concentration， the better the effect. CONCLUSIONS Luteolin may play a role in promoting angiogenesis and bone repair at the fracture site by activating PI3K/Akt signaling pathway and promoting the protein expressions of PI3K and Akt1.

Anti-hyperglycemic fraction from Alternanthera sessilis L. leaves gets elucidated following bioassay-guided isolation and mass spectrometry

Abstract The anecdotal use of Alternanthera sessilis L. as a relief for diabetes has been known in the Philippines for generations, and antidiabetic activity of similar varieties in other countries is likewise documented. However, the compounds responsible for this activity remain unclear. This study aims to isolate the anti-hyperglycemic fraction of local A. sessilis leaves and identify the compounds in this fraction. Methanol extract of A. sessilis leaves and its hexane, ethyl acetate (ASE), and water fractions were administered to alloxan-induced diabetic mice. ASE (250mg/kg) had the highest anti-hyperglycemic activity at 6-h post-treatment (25.81%±12.72%), with almost similar blood glucose reduction rate as metformin (30.13±3.75%, p=0.767). Repeated fractionation employing chromatographic separation techniques followed by in vivo anti-hyperglycemic assay yielded partially purified subfractions. A. sessilis ethyl acetate subfraction 4-2 (100mg/kg) displayed remarkable suppression of blood glucose rise in diabetic mice at 6-h post-treatment (26.45±3.75%, p<0.0001), with comparable activity with metformin (100mg/kg, 27.87±5.65%, p=0.652). Liquid chromatography/mass spectrometry showed eight distinct peaks, with four peaks annotated via the Traditional Chinese Medicine library and custom library for A. sessilis. Among these, luteolin, apigenin, ononin, and sophorabioside were identified as putative compounds responsible for the anti-hyperglycemic activity. This result provided basis for the reported anecdotal claims and potential utility of the local variety of A. sessilis leaves as sources of anti-hyperglycemic agents

Role of three drugs in traumatic proliferative vitreoretinopathy in rabbits / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To investigate the effect of triamcinolone acetonide(TA), artesunate(ART), and luteolin(LU)on the prevention and treatment of traumatic proliferative vitreoretinopathy(TPVR). <p>METHODS: Forty-eight cyanotic blue rabbits were selected to prepare TPVR animal models by making a penetrating eye injury and intravitreal injection of 0.3mL platelet-rich plasma, and were randomly divided into four groups(<i>n</i>=12), in which the vitreous cavity of the control group was injected with 0.1mL saline; The vitreous cavity of the TA group was injected with 0.1mL(1mg/mL)triamcinolone acetonide; The vitreous cavity of the ART group was injected with 0.1mL(20μg/mL)artesunate; 0.1mL(10μg/mL)luteolin was injected into the vitreous cavity of the LU group. The vitreous and retinal proliferation were observed by fundus photography and ocular ultrasound at 1, 2, 3 and 4wk postoperatively. The expression levels of α-SMA and VIM protein in the vitreous fluid of each group of rabbit eyes were detected by Western Blot at 28d postoperatively, and the retinal tissue structure of each group was observed by retinal HE staining. <p>RESULTS: At 28d postoperatively, the TPVR grading of rabbit eyes in the TA, ART and LU groups were significantly lower than that in the control group(<i>P</i><0.05), and the TPVR grading of rabbit eyes in the TA group was significantly lower than that in the ART and LU groups(<i>P</i><0.05). The expression levels of α-SMA and VIM proteins in the vitreous fluid of the rabbit eyes in the TA, ART and LU groups were significantly lower than those in the control group at 28d after surgery(<i>P</i><0.01). The results of HE staining showed that the arrangement of retinal layers in rabbit eyesin the control group were disordered, severely distorted or locally broken, the structure of each layer were unclear, the anterior membrane was obviously thickened, and the retina was obviously detached; The arrangement of retinal layersin rabbit eyes in the LU group were slightly distorted, inflammatory exudation was visible in front of the retina, and the retina was superficially detached; The structure of retina in rabbit eyes in the ART group were clear, with mild edema and superficial detachment; The structure of retinal layers in rabbit eyes in the TA group were clear, the arrangement was still neat, the retinal folds were locally visible, and there was no retinal detachment.<p>CONCLUSION: Intravitreal injection of triamcinolone acetonide, artesunate and luteolin were all effective in preventing and treating traumatic TPVR, among which triamcinolone acetonide has the most obvious effect.

Study on mechanism of combination of Platycodonis Radix and Lilii Bulbus with homology of medicine and food in treating pneumonia / 中国中药杂志

To investigate the potential molecular mechanism of the combination of Platycodonis Radix and Lilii Bulbus with the homology of medicine and food in the treatment of pneumonia by means of network pharmacology and in vitro verification experiment. Under the condition of bioavailability(OB)≥30% and drug-like(DL)≥0.18, the active components of Platycodonis Radix and Lilii Bulbus were screened in TCMSP database; the prediction targets of active components were searched from TCMSP, DrugBank and other databases, and the potential targets of pneumonia were obtained through GeneCards and OMIM database. The common targets were obtained by the intersection of drug and disease targets. The PPI network of common targets was constructed by STRING 11.0, and the core targets were obtained by topological analysis. Then the core targets received GO and KEGG analysis with use of WebGestalt and Metascape. The "component-target-pathway" network was constructed with the help of Cytoscape 3.7.1 software, and the component-target molecular docking verification was carried out with Discovery Studio 2016 software. Finally, the core targets and pathways were preliminarily verified in vitro. In this study, 12 active components were screened, 225 drug prediction targets and 420 potential diseases targets were obtained based on data mining method, and 14 core targets were obtained by topological analysis, including TNF, MMP9, AKT1, IL4 and IL2. The enrichment results of GO and KEGG showed that "Platycodonis Radix and Lilii Bulbus" drug pair may regulate inflammation, cell growth and metabolism by acting on 20 key signaling pathways such as TNF and IL-17, thereby exerting anti-pneumonia effects. The results of molecular docking showed that 12 active components had good binding ability with 14 core targets. In vitro experiment results showed that the core components of "Platycodonis Radix and Lilii Bulbus" drug pair could inhibit the expression of MMP9 and TNF-α by regulating TNF signal pathway. This study confirmed the scientificity and reliability of the prediction results of network pharmacology, and preliminarily revealed the potential molecular mechanism of the compatibility of Platycodonis Radix and Lilii Bulbus in the treatment of pneumonia. It provides a novel insight on systematically exploring the mechanism of the compatible use of Platycodonis Radix and Lilii Bulbus, and has a certain reference value for the research, development and application of new drugs.

Protective effect of Luteolin on oxidative damage of retinal pigment epithelium cells by regulating the Nrf2/HO-1 pathway / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To investigate the protective effect and mechanism of luteolin on H2O2-induced oxidative damage of retinal pigment epithelium(RPE)cells. <p>METHODS:ARPE-19 cells were divided into the control group, H2O2 group, different doses of luteolin groups and Nrf2 inhibitor group, and the oxidative damage model of RPE was prepared by 100μmol/L H2O2, except for the control group. Cell activity was detected by Methyl thiazolyl tetrazolium(MTT)assay and proper experimental concentration of luteolin was determined. The cell morphology and activity was observed in each group. Cell apoptosis rate and reactive oxygen species(ROS)were detected by flow cytometry, malondialdehyde(MDA)and superoxide dismutase(SOD)were detected by kit method, and the expression of caspase-3, poly adeno-sine diphosphate ribose polymerase(PARP), B cell lymphoma-2(Bcl-2), nuclear factor erythroid 2-related factor 2(Nrf2)and heme oxygenase-1(HO-1)proteins were detected by Western blot. <p>RESULTS: 100μmol/L luteolin has toxic effects on ARPE-19 cells, so 25μmol/L and 50μmol/L luteolin were selected for subsequent experiments. The cell activity, SOD activity and the protein expression levels of Bcl-2, Nrf2, HO-1 in 25μmol/L and 50μmol/L luteolin groups were significantly higher than the H2O2 group(<i>P</i><0.05). The apoptosis rate, ROS, MDA content and the protein expression levels of Caspase-3 and PARP in 25μmol/L and 50μmol/L luteolin groups were significantly lower than the H2O2 group(<i>P</i><0.05). The cell activity, SOD activity \〖(13.83±1.49)U/mL <i>vs</i>(22.69±1.83)U/mL\〗 and the protein expression levels of Bcl-2, Nrf2 and HO-1 protein expression in the Nrf2 inhibitor group were significantly lower than the 50μmol/L luteolin group(<i>P</i><0.05). The apoptosis rate, ROS, MDA content \〖(654.96±26.99)<i>vs</i>(446.52±29.42),(3.89±0.29)nmol/mL <i>vs</i>(2.06±0.19)nmol/mL\〗 and the protein expression levels of Caspase-3 and PARP in the Nrf2 inhibitor group were significantly higher than the 50μmol/L luteolin group(<i>P</i><0.05).<p>CONCLUSION: Luteolin can improve the oxidative damage of RPE cells induced by H2O2, and its mechanism may be related to the activation of the Nrf2/HO-1 pathway.

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.

Systems pharmacology dissection of action mechanisms for herbs in osteoporosis treatment / 中草药·英文版

Objective: Osteoporosis has become the biggest cause of non-fatal health issue. Currently, the limitations of traditional anti-osteoporosis drugs such as long-term ill-effects and drug resistance, have raised concerns toward complementary and alternative therapies, particularly herbal medicines and their natural active compounds. Thus, this study aimed to provide an integrative analysis of active chemicals, drug targets and interacting pathways of the herbs for osteoporosis treatment. Methods: Here, we introduced a systematic pharmacology model, combining the absorption, distribution, metabolism, and excretion (ADME) screening model, drug targeting and network pharmacology, to probe into the therapeutic mechanisms of herbs in osteoporosis. Results: We obtained 86 natural compounds with favorable pharmacokinetic profiles and their 58 targets from seven osteoporosis-related herbs. Network analysis revealed that they probably synergistically work through multiple mechanisms, such as suppressing inflammatory response, maintaining bone metabolism or improving organism immunity, to benefit patients with osteoporosis. Furthermore, experimental results showed that all the five compounds (calycosin, asperosaponin VI, hederagenin, betulinic acid and luteolin) enhanced osteoblast proliferation and differentiation in vitro, which corroborated the validity of this system pharmacology approach. Notably, gentisin and aureusidin among the identified compounds were first predicted to be associated with osteoporosis. Conclusion: Herbs and their natural compounds, being characterized as the classical combination therapies, might be engaged in multiple mechanisms to coordinately improve the osteoporosis symptoms. This work may contribute to offer novel strategies and clues for the therapy and drug discovery of osteoporosis and other complex diseases.

Independent and synergistic activity of the flavonoids of Gracilaria corticata as promising antidiabetic agents

The therapeutic approaches for Type 2 Diabetes Mellitus rely most on the usage of oral hypoglycaemic drugs. These drugs have adverse side effects and hence alternative medicines are continuously explored. The present study intends to investigate the antidiabetic potential of the flavonoids present in Gracilaria corticata. The flavonoids were isolated (FEGC) and their inhibitory activity on the carbohydrate hydrolysing enzymes such as α-amylase and α-glucosidase was analysed. The flavonoids were found to inhibit α-amylase and α-glucosidase with an IC50 value of 302 µg and 75 µg respectively. The synergistic effect of FEGC and luteolin was also investigated and the results show that both FEGC and luteolin inhibited synergistically at half their IC50 values. The observations of this study reveal that the flavonoids of G. corticata have potential antidiabetic activity and can act independently or synergistically in the management of Type 2 Diabetes Mellitus

Luteolin attenuates migration and invasion of lung cancer cells via suppressing focal adhesion kinase and non-receptor tyrosine kinase signaling pathway

BACKGROUND/OBJECTIVES: Non-small cell lung cancer is mostly recognized among other types of lung cancer with a poor prognosis by cause of chemotherapeutic resistance and increased metastasis. Luteolin has been found to decrease cell metastasis. However, its underlying mechanisms remain unresolved. The objective of this study was to examine the effect (and its mechanism) of luteolin on the migration and invasion of human non-small cell lung cancer A549 cells.MATERIALS/METHODS: Cell viability was investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Wound healing and transwell assays were evaluated to assess migration and invasion, respectively. Western blot analysis and immunofluorescence were further performed to investigate the role of luteolin and its mechanisms of action.RESULTS: Administration with up to 40 µM luteolin showed no cytotoxic activity on lung cancer A549 cells or non-cancer MRC-5 cells. Additionally, luteolin at 20–40 µM significantly suppressed A549 cells' migration, invasion, and the formation of filopodia in a concentration-dependent manner at 24 h. This is similar with western blot analysis, which revealed diminished the phosphorylated focal adhesion kinase (pFAK), phosphorylated non-receptor tyrosine kinase (pSrc), Ras-related C3 botulinum toxin substrate 1 (Rac1), cell division control protein 42 (Cdc42), and Ras homolog gene family member A (RhoA) expression levels.CONCLUSIONS: Overall, our data indicate that luteolin plays a role in controlling lung cancer cells' migration and invasion via Src/FAK and its downstream Rac1, Cdc42, and RhoA pathways. Luteolin might be considered a promising candidate for suppressing invasion and metastasis of lung cancer cells.

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.

Study on chemical constituents from seeds of Trigonella foenum-graecum / 中草药

Objective: To research the chemical constituents from Trigonella foenum-graecum. Methods: The chemical constituents were separated and purified by sephadex LH-20, silica gel, semi-prepared HPLC and other chromatography techniques. Their structures were elucidated by their physicochemical properties and NMR data. Results: Six steroidal saponins and flavonoids (1-6) were isolated from the ethanol extracts of T. foenum-graecum and identified as 22-methoxy-trigoneoside IIb (1), gitogenin (2), diosgenin (3), luteolin (4), cynaroside (5), and luteolin-7-O-rutinoside (6). Conclusion: Compound 1 is a new compound, and compounds 5 and 6 are obtained for the first time from T. foenum-graecum.

Potential material basis of Kangbingdu Granules for treatment of coronavirus disease 2019 (COVID-19) based on network pharmacology and molecular docking technology / 中草药

Objective: To explore the potential material basis of Kangbingdu Granules for the treatment of coronavirus disease 2019 (COVID-19) through network pharmacology and molecular docking technology. Methods: The chemical constituents and action targets of Isatidis Radix, Forsythiae Fructus, Gypsum Fibrosum, Anemarrhenae Rhizoma, Phragmitis Rhizoma, Rehmanniae Radix Praeparata, Pogostemon cablin, Acoritataninowii Rhizoma and Curcumae Radix in Kangbingdu Granules were searched by TCMSP. The gene corresponding to the target was searched by UniProt database, and Cytoscape 3.6.1 was used to build a medicinal material-compound-target (gene) network. DAVID was used to perform gene ontology (GO) function enrichment analysis and KEGG pathway enrichment analysis to predict its mechanism. Molecular docking of the top 15 components was carried out in the medicinal material-compound-target network with SARS-CoV-2 3CL hydrolase, and molecular docking with bicuculline, luteolin, quercetin and angiotensin-converting enzyme II (ACE2) was performed. Results: The medicinal material-compound-target (gene) network contained eight medicinal materials, 75 compounds and 255 targets. GO function enrichment analysis revealed 161 GO items (P < 0.05), including 65 biological process (BP) items, 36 cell composition (CC) items, and 60 molecular function (MF) items. KEGG pathway enrichment screened 131 signaling pathways (P < 0.05). The results of molecular docking showed that the core active compounds such as bicuculline, luteolin, and quercetin in the Kangbingdu Granules had similar affinities with those recommended by COVID-19. Conclusion: The active compounds in Kangbingdu Granules can interact with angiotensin-converting enzyme II (ACE2) via targets PTGS2, HSP90AB1, and PTGS1 to regulate multiple signaling pathways, thereby exerting therapeutic effects on COVID-19.

Mechanism of Tanreqing Injection on treatment of coronavirus disease 2019 based on network pharmacology and molecular docking / 中草药

Objective: To study the mechanism of Tanreqing Injection (TRQI) on treatment of coronavirus disease 2019 (COVID-19) through network pharmacology and molecular docking, so as to provide theoretical basis for clinical treatment. Methods: The active compounds of TRQI were searched by literature, BATMAN-TCM, and TCMSP database. The potential targets of TRQI active compounds were searched by TCMSP. In Genecards database, “coronavirus” was used as the key word to search for coronavirus targets and the common targets were selected by mapping with TRQI. The network between the active compounds and common targets was established by Cytoscape 3.2.1. The common targets were imported into a STRING database for protein-protein interaction analysis, and the target protein interaction network diagram (PPI) was constructed. The key antiviral targets of TRQI were screened by combining two networks. “GlueGO 2.5.5” plug-in unit in Cytoscape 3.2.1 was used to perform GO biological process and KEGG pathway enrichment analysis. Results: A total of 54 components of TRQI were obtained and corresponding to 287 targets. Among them, there were 54 common targets and 34 key targets. GO analysis obtained 29 biological processes related to the treatment effect of TRQI, and KEGG analysis obtained 70 pathways. The results of molecular docking showed that kaempferol, quercetin, baicalein luteolin, and wogonin had good affinity with SARS-CoV-2 3CL hydrolase. Conclusion: The active compounds in TRQI may act as an antiviral agent by binding SARS-CoV-2 3CL hydrolase and regulating multiple signaling pathways. The molecular mechanism of TRQI in the treatment of COVID-19 indicated the synergistic features of multi-component, multi-target, and multi-pathway of traditional Chinese medicine, which provided an important scientific basis for further elucidating the mechanism of TRQI in the treatment of COVID-19.

Research on active compounds of Maxingyigan Decoction for treatment of coronavirus disease 2019 based on network pharmacology and molecular docking / 中草药

Objective: To explore the active compounds of Maxingyigan Decoction for the treatment of coronavirus disease 2019 (COVID-19). Methods: The chemical constituents and action targets of Ephedra sinica, Armeniacae Semen Amarum, Coicis Semen, and Glycyrrhizae Radix et Rhizoma in Maxingyigan Decoction were retrieved from TCMSP. The database of UniProt and GeneCards were used to query the target genes that corresponding to the active compounds, and then a compound-target (gene) network was constructed by Cytoscape 3.6.1. GO functional enrichment analysis and KEGG enrichment analysis were performed through WebGestalt database to predict its mechanism of action. The main active ingredients were docked with SARS-CoV-2 3CL hydrolase and angiotensin converting enzyme II (ACE2). Results: The compound-target network contained 126 compounds and 266 corresponding targets. The key targets genes included PTGS2, ESR1, PCP4, PPARG, HSP90AA1, NCOA2, etc. GO function enrichment analysis found that 522 GO items were affected by Maxingyigan Decoction, including 12 biological process items, 20 cell composition items, and 17 molecular function items. KEGG enrichment analysis showed that 168 signal pathways were enriched, involving interferon-γ signaling pathway, MAP kinase cascade, T cell activation, chemokines and cytokine signaling pathway-mediated inflammation pathways, etc. The molecular docking results showed that core compounds such as luteolin and quercetin had similar affinity with the recommended drugs used to treat COVID-19. Conclusion: The active compounds in Maxingyigan Decoction may have a therapeutic effect on COVID-19 through binding with 3CL hydrolase and ACE2 to act on targets such as PTGS2, ESR1, PCP4, PPARG, HSP90AA1 and NCOA2 so as to regulate multiple signal pathways.