Luteolin as potential treatment for Huntington's disease: Insights from a transgenic mouse model.

AIMS: The study aimed to evaluate the potential benefits of luteolin treatment in Huntington's disease (HD), an inherited progressive neurodegenerative disorder. METHODS: HD N171-82Q transgenic and WT mice received luteolin or vehicle for treatment at 6 weeks of age. The mice's body weight changes and survival rates were monitored throughout the study, and a series of motor functional tests were conducted. Serum level of the marker NfL was also determined. Immunohistochemical staining and western blotting were utilized to assess the expression of huntingtin aggregates. RESULTS: Luteolin treatment enhanced survival and prevented weight loss in HD mice compared to the vehicle-treated HD group. Furthermore, the luteolin-treated HD mice exhibited enhanced motor coordination and balance and significantly reduced motor dysfunction. Also, luteolin decreased serum NfL levels in HD mice. Notably, the accumulation of huntingtin aggregates was significantly reduced in the brain's cortex, hippocampus, and striatum of luteolin-treated HD mice compared to the vehicle-treated HD group. CONCLUSION: Luteolin holds promise as a therapeutic agent for improving survival outcomes, managing motor dysfunction, and reducing huntingtin aggregates in HD. The findings are of significance as currently, there are no approved therapeutic interventions that reverse HD pathology or slow down its progression.

Fabrication of Luteolin Nanoemulsion by Box-Behnken Design to Enhance its Oral Absorption Via Lymphatic Transport.

Intestinal lymphatic transport offers an alternative and effective way to deliver drugs, such as avoiding first-pass metabolism, enhancing oral bioavailability, and facilitating the treatment of targeted lymphoid-related diseases. However, the clinical use of luteolin (LUT) is limited by its poor water solubility and low bioavailability, and enhancing lymphatic transport by nanoemulsion may be an efficient way to enhance its oral bioavailability. The objective of this work is to prepare the luteolin nanoemulsions (LUT NEs), optimized its preparation parameters by using Box-Behnken design optimization (BBD) and evaluated it in vitro and in vivo. An Caco-2 / Raji B cell co-incubation monolayer model was established to simulate the M-cell pathway, and the differences in the transmembrane transport of LUT and NEs were compared. Cycloheximide (CHX) was utilized to establish rat chylomicron (CM) blocking model, and for investigating the influence of pharmacokinetic parameters in rats thereafter. The results showed that LUT NEs have good stability, the particle sizes were about 23.87 ± 0.57 nm. Compared with LUT suspension, The Papp of LUT NEs was enhanced for 3.5-folds, the oral bioavailability was increased by about 2.97-folds. In addition, after binding with chylomicron, the oral bioavailability of LUT NEs was decreased for about 30% (AUC 0-∞ (µg/L*h): 5.356 ± 1.144 vs 3.753 ± 0.188). These results demonstrated that NEs could enhance the oral absorption of luteolin via lymphatic transport routes.

Mechanism of luteolin induces ferroptosis in nasopharyngeal carcinoma cells.

Nasopharyngeal carcinoma (NPC) originates from the nasopharynx epithelium, and luteolin is recognized as an important anti-cancer agent. This study investigated the effects of luteolin on ferroptosis in NPC cells. NPC cells were cultured and exposed to varying concentrations of luteolin. Cell viability, malondialdehyde (MDA) levels, superoxide dismutase (SOD) activity, glutathione (GSH) levels, Fe2+ concentration, and glutathione peroxidase 4 (GPX4) protein level were assessed. Additionally, SRY-related high-mobility-group box 4 (SOX4) expression was measured. Subsequently, the binding of SOX4 to the growth differentiation factor-15 (GDF15) promoter and GDF15 mRNA levels were evaluated. The impact of the SOX4/GDF15 axis on luteolin-induced ferroptosis in NPC cells was assayed. Luteolin treatment induced cell ferroptosis, evidenced by decreased cell viability, increased MDA and Fe2+ levels, and reduced SOD, GSH, and GPX4 levels. Furthermore, luteolin downregulated SOX4 expression, while overexpression of SOX4 reversed luteolin's pro-ferroptotic effects in NPC cells. SOX4 was found to up-regulate GDF15 transcription by directly binding to its promoter. Conversely, overexpression of GDF15 mitigated the ferroptotic effects induced by luteolin in NPC cells. Therefore, luteolin induces ferroptosis in NPC cells via modulation of the SOX4/GDF15 axis. In conclusion, luteolin reduces the binding of SOX4 to the GDF15 promoter by suppressing SOX4 expression, thereby down-regulating GDF15 transcription levels and inducing ferroptosis in NPC cells.

Luteolin-loaded Invasomes Gel for Transdermal Delivery: Development, Optimization, in-vitro, and Preclinical Evaluation.

Luteolin (LN), is an herbal bioactive flavone and exhibits many pharmacological activities. However, the bioavailability of LN is limited due to its inadequate solubility and significant first-pass metabolism. The present study developed transdermal LN-loaded invasomes (IVM) gel to improve the therapeutic efficacy. The LN-IVM was prepared and optimized by 2 3 factorial designs. LN-IVM was characterized for physicochemical parameters. The optimized LN-IVM (LN-IVMopt) was incorporated into HPMC-K4M gel and evaluated for viscosity, spreadability, and irritation. Further LN-IVM gel was evaluated for drug release, ex-vivo permeation, pharmacokinetic and pharmacodynamics study. LN-IVMopt showed 300.8±2.67 nm of VS, 0.258 of PDI, 89.92±1.29% of EE, and a zeta potential of -18.2 mV. LN-IVM exhibited spherical morphology. FTIR and XRD results demonstrated that LN was encapsulated into IVM matrix. The optimized IVM gel (LN-IVMoptG2) exhibited excellent viscosity, spreadability, and sustained release of LN (91.32±2.95% in 24 h). LN-IVMoptG2 exhibited statistically significant (p < 0.05) higher flux (5.79 µg/h/cm2 ) than LN-gel (2.09 µg/h/cm2 ). The apparent permeability coefficient of plain LN gel and LN- IVMoptG was 1.15×10-5 cm/min and 3.22×10-5 cm/min respectively. LN-IVMoptG2 showed no irritation (score 0.0) throughout the study (60 min). The relative bioavailability of LN from LN-IVMopt-G2 (transdermal) was 2.38±0.19 fold as compared to LN-Sus (oral) and 1.81±0.15-fold than plain LN-gel (transdermal). The LN-IVMoptG2 showed a substantial lessening in the paw volume up to 12 h (17.48±1.94% swelling) than plain LN-gel (44.77±2.82% swelling). The finding concluded that the IVM gel is a novel, effective, and safe approach for the delivery of LN transdermally to improve its therapeutic efficacy.

Combining luteolin and curcumin synergistically suppresses triple-negative breast cancer by regulating IFN and TGF-ß signaling pathways.

Combining two or more chemicals in chemotherapy is rapidly increasing because of its higher efficacy, lower toxicity, lower dosages, and lower drug resistance. Here, we identified a novel combination of luteolin (LUT) and curcumin (CUR), two bioactive compounds from foods, synergistically suppressed triple-negative breast cancer (TNBC) cell proliferation (LUT 30 µM + CUR 20 µM), colony formation (LUT 1 µM + CUR 2 µM), and tumor growth in xenograft mice (LUT 10 mg/kg body weight/day + CUR 20 mg/kg body weight/day, i.p. injection every other day, 5 weeks), while the individual chemical alone did not show these inhibitory effects significantly at the selected concentrations/dosages. Our total RNA transcriptome analysis in xenograft tumors revealed that combining LUT and CUR synergistically activated type I interferon (IFN) signaling and suppressed transforming growth factor-beta (TGF-ß) signaling pathways, which was further confirmed by the expression/activity of several proteins of the pathways in tumors. In addition, this combination of LUT and CUR also synergistically decreased oncoprotein levels of c-Myc and Notch1, the critical molecules required to maintain stem cell properties, tumor clonal evolution, and drug resistance. These results suggest that the combination of LUT and CUR synergistically inhibits TNBC by suppressing multiple cellular mechanisms, such as proliferation, colony formation, and transformation, as well as tumor migration, invasion, and metastasis, via regulating IFN and TGF-ß signaling pathways. Therefore, combining LUT and CUR may be an effective therapeutic agent to treat highly aggressive, drug-resistant TNBC patients after clinical trials.

Elucidation of the anti-colorectal cancer mechanism of Atractylodes lancea by network pharmacology and experimental verification.

Atractylodes lancea which was listed in "Shennong's Materia Medica" and could be used to treat gastrointestinal-associated diseases. However, its roles, core and active ingredients, and mechanisms in treatment of colorectal cancer (CRC) were still unknown. Therefore, network pharmacology and experimental validation were used to clarify the effects, core active ingredients and molecular mechanisms of Atractylodes lancea. We found that Atractylodes lancea has 28 effective active components and 213 potential targets. Seventy-three genes which demonstrate interaction between the Atractylodes lancea and CRC were confirmed. Enrichment analysis showed that 2033 GO biological process items and 144 KEGG pathways. Survival and molecular docking analysis revealed that luteolin as the core component interacted with these genes (Matrix metalloproteinase 3 (MMP3), Matrix metalloproteinase 9 (MMP9), Tissue inhibitor of metalloproteinases 1 (TIMP1), Vascular endothelial growth factor A (VEGFA)) with the lowest binding energy, and these genes were involved in building a prognostic model for CRC. Cellular phenotyping experiments showed that luteolin could inhibit the proliferation and migration of CRC cells and downregulate the expression of MMP3, MMP9, TIMP1, VEGFA probably by Phosphoinositide 3-kinase/ serine/threonine kinase Akt (PI3K/AKT) pathway. To conclude, Atractylodes lancea could inhibit proliferation and migration of CRC cells through its core active ingredient (luteolin) to suppress the expression of MMP3, MMP9, TIMP1, VEGFA probably by PI3K/AKT pathway.

Cloning and Direct Evolution of a Novel 7-O-Glycosyltransferase from Cucurbita moschata and Its Application in the Efficient Biocatalytic Synthesis of Luteolin-7-O-glucoside.

Luteolin-7-O-glucoside(L7G), a glycosylation product of luteolin, is present in a variety of foods, vegetables, and medicinal herbs and is commonly used in dietary supplements due to its health benefits. Meanwhile, luteolin-7-O-glucoside is an indicator component for the quality control of honeysuckle in the pharmacopoeia. However, its low content in plants has hindered its use in animal pharmacological studies and clinical practice. In this study, a novel 7-O-glycosyltransferase CmGT from Cucurbita moschata was cloned, which could efficiently convert luteolin into luteolin-7-O-glucoside under optimal conditions (40 °C and pH 8.5). To further improve the catalytic efficiency of CmGT, a 3D structure of CmGT was constructed, and directed evolution was performed. The mutant CmGT-S16A-T80W was obtained by using alanine scanning and iterative saturation mutagenesis. This mutant exhibited a kcat/Km value of 772 s-1·M-1, which was 3.16-fold of the wild-type enzyme CmGT. Finally, by introducing a soluble tag and UDPG synthesis pathway, the strain BXC was able to convert 1.25 g/L of luteolin into 1.91 g/L of luteolin-7-O-glucoside under optimal conditions, achieving a molar conversion rate of 96% and a space-time yield of 27.08 mg/L/h. This study provides an efficient method for the biosynthesis of luteolin-7-O-glucoside, which holds broad application prospects in the food and pharmaceutical industry.

Long-term effects of luteolin in a mouse model of nephropathic cystinosis.

In infantile nephropathic cystinosis, variants of the CTNS gene cause accumulation of cystine in lysosomes, causing progressive damage to most organs. Patients usually present before 1 year of age with signs of renal Fanconi syndrome. Cysteamine therapy allows cystine clearance from lysosomes and delays kidney damage but does not prevent progression to end-stage kidney disease, suggesting that pathways unrelated to cystine accumulation are also involved. Among these, impaired autophagy, altered endolysosomal trafficking, and increased apoptosis have emerged in recent years as potential targets for new therapies. We previously showed that luteolin, a flavonoid compound, improves these abnormal pathways in cystinotic cells and in zebrafish models of the disease. Herein, we have investigated if prolonged luteolin treatment ameliorates kidney damage in a murine model of cystinosis. To this end, we have treated Ctns-/- mice from 2 to 8 months with 150 mg/kg/day of luteolin. No significant side effects were observed. Compared to untreated animals, analyses of kidney cortex samples obtained after sacrifice showed that luteolin decreased p62/SQSTM1 levels (p <0.001), improved the number, size, and distribution of LAMP1-positive structures (p <0.02), and decreased tissue expression of cleaved caspase 3 (p <0.001). However, we did not observe improvements in renal Fanconi syndrome and kidney inflammation. Kidney function remained normal during the time of the study. These results indicate that luteolin has positive effects on the apoptosis and endo-lysosomal defects of cystinotic proximal tubular cells. However, these beneficial effects did not translate into improvement of renal Fanconi syndrome.

Apoptosis induction and inhibition of invasion and migration in gastric cancer cells by Isoorientin studied using network pharmacology.

BACKGROUND: To investigate the effects of Isoorientin on the apoptosis, proliferation, invasion, and migration of human gastric cancer cells (HGC27 cells). METHODS: We used network pharmacology to predict the targets of drugs and diseases. The CCK-8 assay was used to determine the effects of Isoorientin on the proliferation of HGC27 cells. Flow cytometry was employed to analyze the effects of Isoorientin on cell apoptosis and cell cycle distribution of HGC27 cells. Scratch test and transwell chamber test were conducted to assess the effects of Isoorientin on invasion and migration, respectively. Additionally, qPCR and western blot were performed to examine the impact of Isoorientin on apoptosis-related genes and protein expression, respectively. RESULTS: The Isoorientin significantly inhibited the proliferation, migration, and invasion of HGC27 cells compared to the control group. Furthermore, Isoorientin induced apoptosis in HGC27 cells by upregulating the relative expression of Bax and caspase-3 while downregulating the relative expression of p-PI3K, p-AKT, and Bcl-2 proteins. CONCLUSION: The Isoorientin exhibits inhibitory effects on the proliferation, invasion, and migration of HGC27 cells, and induces apoptosis in gastric cancer cells.

Network pharmacology and molecular docking analysis predict the mechanisms of Huangbai liniment in treating oral lichen planus.

This study explored the mechanism of Huangbai liniment (HB) for the treatment of oral lichen planus (OLP) through network pharmacology and molecular docking techniques. The study identified HB' active ingredients, therapeutic targets for OLP, and associated signaling pathways. The chemical composition of HB was screened using the HERB database. The disease targets of OLP were obtained through the GeneCards and OMIM databases. A protein-protein interactions network was constructed with the String platform. Topological analysis was performed using Cytoscape software to identify core targets. Gene ontology and Kyoto encyclopedia of genes and genomes pathway enrichment analysis were performed using the Hiplot database, and the active ingredients and core targets were verified by molecular docking. Date analysis showed that the active composition of HB in the treatment of OLP were quercetin, wogonin, kaempferol, and luteolin. This survey identified 10 potential therapeutic targets, including TNF, CXCL8, IL-6, IL1B, PIK3R1, ESR1, JUN, AKT1, PIK3CA, and CTNNB1. Molecular docking revealed stable interactions between OLP' key targets and HB. These key targets were predominantly involved in the PI3K-Akt signaling pathway, AGE-RAGE signaling pathway, TNF signaling pathway, and HIF-1 signaling pathway. HB plays a crucial role in the treatment of OLP, acting on multiple targets and pathways, particularly the PI3K-Akt signaling pathway. It regulated biological processes like the proliferation of epithelial cells and lymphocytes and mediates the expression of transcription factors, cytokines, and chemokines. Therefore, this study provides a theoretical basis for the clinical trial and application of HB in the therapy of OLP.

The role of DPYD and the effects of DPYD suppressor luteolin combined with 5-FU in pancreatic cancer.

BACKGROUND: Despite advances in the treatment of cancer, pancreatic ductal adenocarcinoma (PDAC) remains highly lethal due to the lack of effective therapies. Our previous study showed that Luteolin (Lut), a flavonoid, suppressed pancreatocarcinogenesis and reduced the expression of dihydropyrimidine dehydrogenase (DPYD), an enzyme that degrades pyrimidines such as 5-fluorouracil (5-FU), in PDACs. In this study, we investigated the role of DPYD and evaluated the therapeutic potential of combining 5-FU with Lut in PDACs. METHODS AND RESULTS: PDAC cells overexpressing DPYD showed increased proliferation, and invasiveness, adding to the resistance to 5-FU. The xenograft tumors of DPYD-overexpressing PDAC cells also exhibit enhanced growth and invasion compared to the control xenograft tumors. RNA-seq analysis of the DPYD-overexpressing PDAC xenograft tumors revealed an upregulation of genes associated with metallopeptidase activity-MMP9 and MEP1A. Furthermore, the overexpression of MEP1A in PDAC was associated with invasion. Next, we investigated the combined effects of Lut, a DPYD suppressor, and 5-FU on DPYD-overexpressing xenograft tumors and PDAC of Pdx1-Cre; LSL-KrasG12D/+; Trp53flox/flox(KPPC) mice. Neither single administration of 5-FU nor Lut showed significant inhibitory effects; however, the combined administration of 5-FU and Lut exhibited a significant tumor-suppressive effect in both the xenograft tumors and KPPC models. CONCLUSION: We have elucidated that DPYD expression contributes to proliferation, invasiveness, and 5-FU resistance, in PDACs. The combination therapy of Lut and 5-FU holds the potential for enhanced efficacy against PDACs.

Progress, pharmacokinetics and future perspectives of luteolin modulating signaling pathways to exert anticancer effects: A review.

Luteolin (3, 4, 5, 7-tetrahydroxyflavone) are natural flavonoids widely found in vegetables, fruits and herbs, with anti-tumor, anti-inflammatory and antioxidant effects, and also play an anti-cancer effect in various cancers such as lung, breast, prostate, and liver cancer, etc. Specifically, the anti-cancer mechanism includes regulation of various signaling pathways to induce apoptosis of tumor cells, inhibition of tumor cell proliferation and metastasis, anti-angiogenesis, regulation of immune function, synergistic anti-cancer drugs and regulation of reactive oxygen species levels of tumor cells. Specific anti-cancer mechanisms include regulation of various signaling pathways to induce apoptosis, inhibition of tumor cell proliferation and metastasis, anti-angiogenesis, reversal of epithelial-mesenchymal transition, regulation of immune function, synergism with anti-cancer drugs and regulation of reactive oxygen species levels in tumor cells. This paper integrates the latest cutting-edge research on luteolin and combines it with the prospect of future clinical applications, aiming to explore the mechanism of luteolin exerting different anticancer effects through the regulation of different signaling pathways, so as to provide a practical theoretical basis for the use of luteolin in clinical treatment and hopefully provide some reference for the future research direction of luteolin.

Luteolin protects mouse hippocampal neuronal cells against isoflurane-induced neurotoxicity through miR-214/PTEN/Akt pathway.

Isoflurane is one of the most commonly used anaesthetic agents in surgery procedures. During the past decades, isoflurane has been found to cause impairment in neurological capabilities in new-borns and elderly patients. Luteolin is a flavonoid that has been documented to possess a neuroprotective effect. Here we investigated the putative neuroprotective effects of luteolin on isoflurane-induced neurotoxicity in mouse hippocampal neuronal HT22 cells and explored the potential mechanisms. We demonstrated that luteolin improved mitochondrial dysfunction and reduced oxidative stress and apoptosis in isoflurane-treated HT22 cells, and thus inhibiting the isoflurane-induced neuronal injury. Further investigations showed that isoflurane exposure caused miR-214 downregulation, which could be mitigated by treatment with luteolin. Knockdown of miR-214 attenuated the neuroprotection of luteolin on isoflurane-induced neuronal injury. More importantly, luteolin inhibited isoflurane-caused regulation of the PTEN/Akt pathway, while miR-214 knockdown altered the regulatory effect of luteolin on the PTEN/Akt pathway. Furthermore, the effects of miR-214 knockdown on the neuroprotection of luteolin could also be prevented by knockdown of PTEN, implying that the neuroprotective effect of luteolin was mediated by miR-214/PTEN/Akt signaling pathway. These findings provided evidence for the potential application of luteolin in preventing isoflurane-induced neurotoxicity.

Dietary intake of luteolin is negatively associated with all-cause and cardiovascular mortality in chronic kidney disease patients.

BACKGROUND: Luteolin (Lut), a flavonoid present in the daily diet, exhibits potent anti-inflammatory and renoprotective effects. However, the association between Lut and chronic kidney disease (CKD) remains uncertain. The objective of this study is to explore the potential correlation. METHODS: A total of 2,393 CKD patients were enrolled in a prospective cohort in the National Health and Nutrition Examination Survey (NHANES). A 24-h dietary recall was utilized to estimate the intake of dietary Lut based on the type and amount of food consumed. The National Death Index mortality data was utilized to ascertain all-cause and cardiac mortality (as of December 27, 2023). Cox proportional hazards model was used to estimate the relationship between Lut intake and mortality risk. RESULTS: The median Lut intake was 0.305 mg/day, with interquartile range was 0.105-0.775 mg/day. During the follow-up period (median, 93 months), 682 all-cause deaths (217 cardiovascular disease [CVD] deaths) were recorded. Per unit increase in Lut intake reduced all-cause mortality by 27% (P < 0.001) and cardiac mortality by 34% (P = 0.01) in CKD patients. There was an inverse dose-response association between Lut intake (range: 0-8.945 mg/day) and mortality risk. Consistent results were also shown when stratified by age, sex, race, marital status, body mass index, CKD stage, urine protein creatinine ratio strata, CKD progression risk, hypertension, and CVD. CONCLUSION: Dietary Lut intake is associated with a reduction in all-cause and cardiac mortality among CKD patients, potentially attributable to the anti-inflammatory characteristics of Lut.

Luteolin: A promising modulator of apoptosis and survival signaling in liver cancer.

Due to the increasing incidence of cancer and the difficulties in determining the safety profile of existing therapeutic approaches, cancer research has recently become heavily involved in the search for new therapeutic approaches. The therapeutic significance of natural substances, especially flavonoids, against the onset and progression of cancer has been emphasized in traditional food-based medicine. Interestingly, the flavone luteolin possesses biological effects that have been linked to its anti-inflammatory, antioxidant, and anticancer effects. Luteolin interacts with several downstream chemicals and signaling pathways, including those involved in apoptosis, autophagy, cell cycle progression, and angiogenesis, to exert its anticancer effects on various cancerous cells. A complete understanding of both intrinsic and extrinsic apoptotic pathways, autophagy, and, most critically, the nanodelivery of luteolin in liver cancer is provided in the current review.

Dissecting the antitumor effects of Scutellaria barbata: Initial insights into the metabolism of scutellarin and luteolin by gut microbiota.

The high prevalence of cancer and detrimental side effects associated with many cancer treatments necessitate the search for effective alternative therapies. Natural products are increasingly being recognized and investigated for their potential therapeutic benefits. Scutellaria barbata D. Don (SBD), a plant with potent antitumor properties, has attracted significant interest from oncology researchers. Its primary flavonoid components-scutellarin and luteolin-which have limited oral bioavailability due to poor absorption. This hinders its application for cancer treatment. The gut microbiota, which is considered a metabolic organ, can modulate the biotransformation of compounds, thereby altering their bioavailability and efficacy. In this study, we employed liquid chromatography tandem mass spectrometry (LC-MS/MS 8060) and ion trap-time of flight (LC-MSn-IT-TOF) analysis to investigate the ex vivo metabolism of scutellarin and luteolin by the gut microbiota. Five metabolites and one potential metabolite were identified. We summarized previous studies on their antitumor effects and performed in vitro tumor cell line studies to prove their antitumor activities. The possible key pathway of gut microbiota metabolism in vitro was validated using molecular docking and pure enzyme metabolic experiments. In addition, we explored the antitumor mechanisms of the two components of SBD through network pharmacology, providing a basis for subsequent target identification. These findings expand our understanding of the antitumor mechanisms of SBD. Notably, this study contributes to the existing body of knowledge regarding flavonoid biotransformation by the gut microbiota, highlighting the therapeutic potential of SBD in cancer treatment. Moreover, our results provide a theoretical basis for future in vivo pharmacokinetic studies, aiming to optimize the clinical efficacy of SBD in oncological applications.

Luteolin enhances drug chemosensitivity by downregulating the FAK/PI3K/AKT pathway in paclitaxel­resistant esophageal squamous cell carcinoma.

Drug resistance is a key factor underlying the failure of tumor chemotherapy. It enhances the stem­like cell properties of cancer cells, tumor metastasis and relapse. Luteolin is a natural flavonoid with strong anti­tumor effects. However, the mechanism(s) by which luteolin protects against paclitaxel (PTX)­resistant cancer cell remains to be elucidated. The inhibitory effect of luteolin on the proliferation of EC1/PTX and EC1 cells was detected by cell counting kit­8 assay. Colony formation and flow cytometry assays were used to assess clonogenic capacity, cell cycle and apoptosis. Wound healing and Transwell invasion tests were used to investigate the effects of luteolin on the migration and invasion of EC1/PTX cells. Western blotting was used to detect the protein levels of EMT­related proteins and stem cell markers after sphere formation. Parental cells and drug­resistant cells were screened by high­throughput sequencing to detect the differential expression of RNA and differential genes. ELISA and western blotting were used to verify the screened PI3K/Akt signaling pathway, key proteins of which were explored by molecular docking. Hematoxylin and eosin staining and TUNEL staining were used to observe tumor xenografts on morphology and apoptosis in nude mice. The present study found that luteolin inhibited tumor resistance (inhibited proliferation, induced cell cycle arrest and apoptosis and hindered migration invasion, EMT and stem cell spherification) in vitro in PTX­resistant esophageal squamous cell carcinoma (ESCC) cells. In addition, luteolin enhanced drug sensitivity and promoted the apoptosis of drug­resistant ESCC cells in combination with PTX. Mechanistically, luteolin may inhibit the PI3K/AKT signaling pathway by binding to the active sites of focal adhesion kinase (FAK), Src and AKT. Notably, luteolin lowered the tumorigenic potential of PTX­resistant ESCC cells but did not show significant toxicity in vivo. Luteolin enhanced drug chemosensitivity by downregulating the FAK/PI3K/AKT pathway in PTX­resistant ESCC and could be a promising agent for the treatment of PTX­resistant ESCC cancers.

Exploring the mechanism of luteolin improving immune and inflammatory responses in systemic sclerosis based on systems biology and cell experiments.

There is a growing trend of applying traditional Chinese medicine (TCM) to treat immune diseases. This study reveals the possible mechanism of luteolin, an active ingredient in the core prescription of TCM, in alleviating systemic sclerosis (SSc) inflammation. Bibliometrics was performed to retrieve the core keywords of SSc inflammation. The key inflammatory indicators in the serum samples of 50 SSc patients were detected by ELISA. Data mining was applied for correlation analysis, association rule analysis, and binary logistic regression analysis on the clinical indicators and medication of 50 SSc patients before and after treatment to determine the core prescription. Network pharmacology was used for identifying candidate genes and pathways; molecular docking was conducted to determine the core monomer components of the prescription, providing a basis for subsequent in vitro molecular mechanism research. The effect of luteolin on SSc-human dermal fibroblasts (HDF) viability and inflammatory factors was evaluated by means of ELISA, RT-PCR, and Western blot. The role of TNF in inflammation was explored by using a TNF overexpression vector, NF-κB inhibitor (PKM2), and SSc-HDF. The involvement of TNF/NF-κB pathway was validated by RT-PCR, Western blot, and immunofluorescence. TCM treatment partially corrected the inflammatory changes in SSc patients, indicating its anti-inflammatory effects in the body. Atractylodes, Yam, Astragalus root, Poria cocos, Pinellia ternata, Salvia miltiorrhiza, Safflower, Cassia twig, and Angelica were identified as the core prescriptions for improving inflammatory indicators. Luteolin was the main active ingredient in the prescription and showed a strong binding energy with TNF and NF-κB. Luteolin exerted anti-inflammatory effects in vitro by reducing inflammatory cytokines in SSc-HDF and inhibiting the activation of TNF/NF-κB. Mechanistically, luteolin inhibited the activation of the TNF/NF-κB pathway in SSc-HDF, as manifested by an increase in extranuclear p-P65 and TNF but a decrease in intranuclear p-P65. Interestingly, the addition of PKM2 augmented the therapeutic function of luteolin against inflammation in SSc-HDF. Our study showed the TCM alleviates the inflammatory response of SSc by inhibiting the activation of the TNF/NF-κB pathway and is an effective therapeutic agent for the treatment of SSc.

A novel electrochemical sensor for detection of luteolin in food based on 3D networked electrically interconnected SiO2@GO/MXene composite.

Luteolin (Lu), a compound with various biochemical and pharmacological activities beneficial to human health, has attracted researchers' attention. This study proposes an efficient and scalable method using ultrasound to intercalate graphene oxide (GO)-coated silica spheres (SiO2) into MXenes, resulting in a 3D conductive interconnected structural composite material. Characterization of the composite material was conducted using SEM, TEM, XRD, XPS, and Raman spectroscopy. MXenes exhibit excellent electrical conductivity, and the SiO2@GO surface with abundant hydroxyl and silanol groups provides high-binding active sites that facilitate Lu molecule enrichment. The formation of the 3D conductive interconnected structural composites enhances charge transport, significantly improving sensor sensitivity. Consequently, the sensor demonstrates excellent detection capabilities (detection range 0.03-7000 nM, detection limit 12 pM). Furthermore, the sensor can be applied to quantitative determination of Lu in real samples, including chrysanthemums, Jiaduobao, honeysuckle, purple perilla, and peanut shells, achieving recoveries between 98.2 and 104.7%.

Luteolin promotes neuronogenesis in hippocampus of chronic unpredictable mild stress rats and primary hippocampus of fetal rats.

OBJECTIVE: To investigate the effects of luteolin on chronic unpredictable mild stress (CUMS)-induced depressive rats and corticosterone (CORT)-induced depressive primary hippocampal neurons, and to elucidate the mechanism behind the action. METHODS: The antidepressant mechanism of luteolin was studied by using CUMS rat model and primary hippocampal neurons in fetal rats. In vivo, novelty suppressed feeding, open-field and sucrose preference tests as well as Morris water maze were evaluated. The content of brain derived neurotrophic factor (BDNF), 5-hydroxytryptamine (5-HT), norepinephrine (NE), and dopamine (DA) in serum were detected by enzyme-linked immunosorbent assay. The mechanisms of luteolin were explored based on neurotrophin and hippocampal neurogenesis, and proliferation. Survival of the septo-temporal axis in hippocampus was assayed using the 5-bromo-2-deoxyuridine (BrdU), the expression of BDNF, neurotrophin-3 (NT-3), and nerve growth factor (NGF) in hippocampus dentate gyrus region were measured by Western-blotting. In vitro, BDNF, NT-3, tropomyosin receptor kinase B (TrkB), and phosphorylated cyclic adenosine monophosphate responsive element binding protein (p-CREB) were detected through the high content analysis (HCA) to investigate neurotrophin and apoptosis. RESULTS: Induction of CUMS in rats induced depressive symptoms, while luteolin significantly enhanced sucrose consumption, decreased feeding latency, increased locomotor activity, escape latency, distance of target quadrant and regulated the content of depressive-like biomarkers. Histology analysis revealed that luteolin increased the abundance of new born neurons that had been labeled with BrdU, BrdU + neuronal nuclear antigen, and BrdU + doublecortin in septo-temporal axis of S2 (mid-septal) and T3 (mid-temporal). Moreover, expression of BDNF, NT-3, and NGF increased significantly in the septo-temporal axis of S2 and T3. HCA showed increased expression of BDNF, NT-3, TrkB and p-CREB in primary hippocampal neurons. CONCLUSION: The results provided direct evidence that luteolin has an antidepressant effect and could effectively promote the regeneration of the septotemporal axis nerve and hippocampal neuronutrition, which suggested that the antidepressant effect of luteolin may be related to hippocampal neurogenesis.