Luteolin enhances paclitaxel-induced apoptosis in human breast cancer MDA-MB-231 cells by blocking STAT3

Engineered extracellular vesicles for combinatorial TNBC therapy: SR-SIM-guided design achieves substantial drug dosage reduction

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer that has no therapeutic targets, relies on chemotherapeutics for treatment, and is in dire need of novel therapeutic approaches for improved patient outcomes. Extracellular vesicles (EVs) serve as intercellular communicators and have been proposed as ideal drug delivery vehicles. Here, EVs were engineered with RNA nanotechnology to develop TNBC tumor inhibitors. Using super resolved-structured illumination microscopy, EVs were optimized for precise Survivin small interfering RNA (siRNA) conjugated to chemotherapeutics loading and CD44 aptamer ligand decoration, thereby enhancing specificity toward TNBC cells. Conventional treatments typically employ chemotherapy drugs gemcitabine (GEM) and paclitaxel (PTX) at dosages on the order of mg/kg respectively, per injection (intravenous) in mice. In contrast, engineered EVs encapsulating these drugs saw functional tumor growth inhibition at significantly reduced concentrations: 2.2 μg/kg for GEM or 5.6 μg/kg for PTX, in combination with 21.5 μg/kg survivin-siRNA in mice. The result is a substantial decrease in the chemotherapeutic dose required, by orders of magnitude, compared with standard regimens. In vivo and in vitro evaluations in a TNBC orthotopic xenograft mouse model demonstrated the efficacy of this decreased dosage strategy, indicating the potential for decreased chemotherapy-associated toxicity.

Phenolic Contents, Antioxidant Activities, LCMS Profiles of Mespilus germanica Leaf Extract and Effects on mRNA Transcription Levels of Apoptotic, Autophagic, and Necrotic Genes in MCF7 and A549 Cancer Cell Lines

Cancer, defined by the continuous, uncontrollable proliferation of cells in the human body, is a disease with a rapidly increasing incidence and mortality rate. Scientists are looking for novel ways to cure and prevent this sneaky disease because of the toxicity of contemporary chemotherapy and the cancer cells' resilience to anticancer drugs. Determining the effect of herbal medicines, which do not have as harmful side effects as synthetic drugs, on cancer cell lines is an essential preliminary study in the production of effective drugs against cancer. In this study, the phenolic acid profile, antioxidant capacity, and cytotoxicity of the medicinal plant Mespilus germanica (MG) leaf extract were determined, and its effects on the expression of some apoptotic, necrotic, and autophagic pathway genes of MCF7 (Human breast cancer line) and A549 (Human lung cancer line) and healthy HDF (Human Dermal Fibroblasts) cells were investigated for the first time. The LCMS device detected many important phenolic compounds previously reported to act against cancer cells in Mespilus germanica leaf extract. DPPH and total phenolic content showed high antioxidant capacity. The cytotoxicity of MG was determined by the MTT method. The levels of mRNA transcription for Atg5, Atg3, Rıpk1, Bcl2, Bax, Apaf1, Caspase-8, Caspase-7, Caspase-3, and Caspase-9, as well as the expression patterns of the DNA damage markers P53 and Parp-1 genes, were assessed. MG leaf extract did not cause significant toxicity against healthy HDF cells. However, it had a cytotoxic effect on A549 and MCF7 cancer cell lines, increasing the transcription levels of essential genes involved in cell death mechanisms. This research is the first to analyze the phenolic components and antioxidant capabilities of leaf extracts from Mespilus germanica. Additionally, it investigates the impact of these extracts on crucial genes involved in cell death pathways of A549 lung cancer, MCF7 breast cancer, and non-cancerous HDF (Human Dermal Fibroblasts) cells.

The role of artificial intelligence in the development of anticancer therapeutics from natural polyphenols: Current advances and future prospects

Natural polyphenols, abundant in the human diet, are derived from a wide variety of sources. Numerous preclinical studies have demonstrated their significant anticancer properties against various malignancies, making them valuable resources for drug development. However, traditional experimental methods for developing anticancer therapies from natural polyphenols are time-consuming and labor-intensive. Recently, artificial intelligence has shown promising advancements in drug discovery. Integrating AI technologies into the development process for natural polyphenols can substantially reduce development time and enhance efficiency. In this study, we review the crucial roles of natural polyphenols in anticancer treatment and explore the potential of AI technologies to aid in drug development. Specifically, we discuss the application of AI in key stages such as drug structure prediction, virtual drug screening, prediction of biological activity, and drug-target protein interaction, highlighting the potential to revolutionize the development of natural polyphenol-based anticancer therapies.

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.

Enhanced Apoptotic Effects in MDA-MB-231 Triple-Negative Breast Cancer Cells Through a Synergistic Action of Luteolin and Paclitaxel

BACKGROUND AND AIM

 According to reports on cancer incidence in 2020, breast cancer became the leading malignancy among women worldwide. This multistep disease involves genetic and environmental factors. Paclitaxel, a naturally occurring antimitotic substance, is a widely used chemotherapeutic drug for treating various human malignancies, including breast cancer. However, its major drawback is its extensive toxicity. This limitation can be mitigated through combination therapy with natural products like luteolin. Studies suggest that luteolin has anticancer properties, as it inhibits cancer cell growth and induces apoptosis in breast, lung, and colon cancers. This study aims to investigate the synergistic anticancer effects of combining luteolin and paclitaxel on breast cancer cells.

METHODS

Breast cancer cell line (MDA-MB-231) was utilized for this study. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was then conducted to check the cell viability. This was followed by a morphology study conducted under a phase contrast microscope. Morphological analysis revealed pronounced cell shrinkage and membrane blebbing, indicative of apoptosis when treated with the combination at their IC50 values. Gene expression results further confirmed the anticancer properties by showing significant downregulation of the B-cell lymphoma-2 (BCL-2) anti-apoptotic gene. These findings suggest that the luteolin-paclitaxel combination exerts a synergistic effect, enhancing anticancer activity in breast cancer cells. Reverse transcriptase polymerase chain reaction (RT-PCR) was done to analyze the genes involved in apoptosis. Finally, the data collected was statistically analyzed to confirm the reliability of the study.

RESULTS

The combination of 1 μM/ml of paclitaxel and increasing concentrations of luteolin showed a great percentage of reduction in cell viability and the IC50 value of luteolin concentration was around 40 μM/ml. The morphology study revealed that the cancer cells showed shrinkage and blebbing on treatment with 40 μM/ml. At the same IC50 concentration, the combination of luteolin and paclitaxel resulted in a significant downregulation of BCL-2 mRNA expression in breast cancer cells compared to luteolin alone.

CONCLUSION

The combination of paclitaxel and luteolin has a synergistic effect on breast cancer cells and shows potential as a treatment for various cancers. Given these promising results, the paclitaxel and luteolin combination could be developed into a potent therapeutic strategy for treating various cancers. Future research should include in vivo studies to further assess the therapeutic potential and safety profile of this combination.

Application of Luteolin in Neoplasms and Nonneoplastic Diseases

Researchers are amazed at the multitude of biological effects of 3',4',5,7-tetrahydroxyflavone, more commonly known as luteolin, as it simultaneously has antioxidant and pro-oxidant, as well as antimicrobial, anti-inflammatory, and cancer-preventive, properties. The anticancer properties of luteolin constitute a mosaic of pathways due to which this flavonoid influences cancer cells. Not only is it able to induce apoptosis and inhibit cancer cell proliferation, but it also suppresses angiogenesis and metastasis. Moreover, luteolin succeeds in cancer cell sensitization to therapeutically induced cytotoxicity. Nevertheless, apart from its promising role in chemoprevention, luteolin exhibits numerous potential utilizations in patients with conditions other than neoplasms, which include inflammatory skin diseases, diabetes mellitus, and COVID-19. This review aims to present the multidimensionality of the luteolin's impact on both neoplastic and nonneoplastic diseases. When it comes to neoplasms, we intend to describe the complexity of the molecular mechanisms that underlay luteolin's anticancer effectiveness, as well as to prove the usefulness of integrating this flavonoid in cancer therapy via the analysis of recent research on breast, colon, and lung cancer. Regarding nonneoplastic diseases, this review aims to emphasize the importance of researching the potential of luteolin in areas such as diabetology, virology, and dermatology as it summarizes the most important discoveries in those fields regarding its application.

From nature to therapy: Luteolin's potential as an immune system modulator in inflammatory disorders

Inflammation is an essential immune response that helps fight infections and heal tissues. However, chronic inflammation has been linked to several diseases, including cancer, autoimmune disorders, cardiovascular diseases, and neurological disorders. This has increased interest in finding natural substances that can modulate the immune system inflammatory signaling pathways to prevent or treat these diseases. Luteolin is a flavonoid found in many fruits, vegetables, and herbs. It has been shown to have anti-inflammatory effects by altering signaling pathways in immune cells. This review article discusses the current research on luteolin's role as a natural immune system modulator of inflammatory signaling mechanisms, such as its effects on nuclear factor-kappa B, mitogen-activated protein kinases, Janus kinase/signal transducer and activator of transcription, and inflammasome signaling processes. The safety profile of luteolin and its potential therapeutic uses in conditions linked to inflammation are also discussed. Overall, the data point to Luteolin's intriguing potential as a natural regulator of immune system inflammatory signaling processes. More research is needed to fully understand its mechanisms of action and possible therapeutic applications.

Synergistic effects of flavonoids and paclitaxel in cancer treatment: a systematic review

Paclitaxel is a natural anticancer compound with minimal toxicity, the capacity to stabilize microtubules, and high efficiency that has remained the standard of treatment alongside platinum-based therapy as a remedy for a variety of different malignancies. In contrast, polyphenols such as flavonoids are also efficient antioxidant and anti-inflammatory and have now been shown to possess potent anticancer properties. Therefore, the synergistic effects of paclitaxel and flavonoids against cancer will be of interest. In this review, we use a Boolean query to comprehensively search the well-known Scopus database for literature research taking the advantage of paclitaxel and flavonoids simultaneously while treating various types of cancer. After retrieving and reviewing the intended investigations based on the input keywords, the anticancer mechanisms of flavonoids and paclitaxel and their synergistic effects on different targets raging from cell lines to animal models are discussed in terms of the corresponding involved signaling transduction. Most studies demonstrated that these signaling pathways will induce apoptotic / pro-apoptotic proteins, which in turn may activate several caspases leading to apoptosis. Finally, it can be concluded that the results of this review may be beneficial in serving as a theoretical foundation and reference for future studies of paclitaxel synthesis, anticancer processes, and clinical applications involving different clinical trials.

Folate receptor targeted NIR cleavable liposomal delivery system augment penetration and therapeutic efficacy in breast cancer

BACKGROUND

Liposomes are predominantly used sorts of nanocarriers for active targeted delivery through surface functionalization using targeting ligand. The folate receptors are overexpressed in various cancers including breast cancer and because of its binding aptitude specifically to folate receptors, folic acid became the attractive ligand.

METHODS

In this research, we have developed a folate and Poly-l-Lysine conjugate and coated this conjugate onto the liposomes. The prepared liposomes were characterized using DLS, FTIR, NMR, SEM, TEM, XRD, AFM, stability and drug release studies. Furthermore, In vitro studies were carried out on FR overexpressed breast cancer cell line.

RESULTS

The FA-LUT-ABC-Lip have diameter of 183 ± 3.17 nm with positive surface charge +33.65 ± 3 mV and the drug release studies confirm the NIR responsive payload cleavage. The coated formulation (in presence of NIR light) effectively reduced the IC₅₀ values and kills breast cancer cells through FR mediated internalization and accelerated drug release. Moreover, LUT Formulation shows anticancer effect due to significant inhibition of cell migration and proliferation by regulating VEGF expression and induced apoptosis through the caspase-3 up-regulation.

CONCLUSION

It is evident from the in vitro studies that the formulation was found to be very effective and can be explored for triggered and targeted delivery of the substances through active targeting.

GENERAL SIGNIFICANCE

Combining receptor mediated drug delivery with triggered release aid in more amounts of drug reaching the target site and achieving enhanced therapeutic activity.

The anti-leukemic activity of a luteolin-apigenin enriched fraction from an edible and ethnomedicinal plant, Elsholtzia stachyodes, is exerted through an ER stress/autophagy/cell cycle arrest/ apoptotic cell death signaling axis

BACKGROUND

Elsholtzia is a genus in the family Lamiaceae, and some species in this genus are commonly used for food and in ethnomedicinal formulations by some ethnic groups of China and Thailand. Despite their apparent utility, few studies have been conducted to evaluate their potential as sources of medicinally active agents.

PURPOSE

We aimed to investigate the cytotoxicity of ethanolic extracts from three selected edible plant species of the genus Elsholtzia and the most promising extract was further characterized for the bioactive constituents and signaling mechanisms associated with the anti-leukemic activity.

MATERIALS AND METHODS

Ethanolic extracts were screened for cytotoxicity using flow cytometry. HPLC and LC-MS were used to analyze the chemical constituents of the most potent fraction from E. stachyodes. The relevant mechanism of action was assessed by western blot and multispectral imaging flow cytometry (MIFC).

RESULTS

The most potent anti-leukemic activity was observed with the ethanolic extract from E. stachyodes. Luteolin and apigenin were characterized as the major constituents in the fraction from E. stachyodes. Mechanistically, the luteolin-apigenin enriched fraction (LAEF) induced the UPR, increased autophagic flux, induced cell cycle arrest and apoptotic cell death. LAEF showed significantly less cytotoxicity towards peripheral blood mononuclear cells (PBMCs) as compared to leukemia cell lines.

CONCLUSION

This study is the first to report E. stachyodes as a new source of luteolin and apigenin which are capable of triggering leukemic cell death. This could lead to a novel strategy against leukemia using ethnomedicinal plant extracts as an alternative or supplemental anti-cancer agent.

Salt-Tolerant Plants, Halophytes, as Renewable Natural Resources for Cancer Prevention and Treatment: Roles of Phenolics and Flavonoids in Immunomodulation and Suppression of Oxidative Stress towards Cancer Management

Halophytes and xerophytes, plants with adequate tolerance to high salinity with strong ability to survive in drought ecosystem, have been recognized for their nutritional and medicinal values owing to their comparatively higher productions of secondary metabolites, primarily the phenolics, and the flavonoids, as compared to the normal vegetation in other climatic regions. Given the consistent increases in desertification around the world, which are associated with increasing salinity, high temperature, and water scarcity, the survival of halophytes due to their secondary metabolic contents has prioritized these plant species, which have now become increasingly important for environmental protection, land reclamation, and food and animal-feed security, with their primary utility in traditional societies as sources of drugs. On the medicinal herbs front, because the fight against cancer is still ongoing, there is an urgent need for development of more efficient, safe, and novel chemotherapeutic agents, than those currently available. The current review describes these plants and their secondary-metabolite-based chemical products as promising candidates for developing newer cancer therapeutics. It further discusses the prophylactic roles of these plants, and their constituents in prevention and management of cancers, through an exploration of their phytochemical and pharmacological properties, with a view on immunomodulation. The important roles of various phenolics and structurally diverse flavonoids as major constituents of the halophytes in suppressing oxidative stress, immunomodulation, and anti-cancer effects are the subject matter of this review and these aspects are outlined in details.

Therapeutic Potential of Luteolin on Cancer

Cancer is a global concern, as the rate of incidence is increasing each year. The challenges related to the current chemotherapy drugs, such as the concerns related to toxicity, turn to cancer therapeutic research to discover alternative therapy strategies that are less toxic to normal cells. Among those studies, the use of flavonoids—natural compounds produced by plants as secondary metabolites for cancer therapy—has been a hot topic in cancer treatment. Luteolin, a flavonoid that has been present in many fruits, vegetables, and herbs, has been identified to exhibit numerous biological activities, including anti-inflammatory, antidiabetic, and anticancer properties. The anticancer property of Luteolin has been extensively researched in many cancer types and has been related to its ability to inhibit tumor growth by targeting cellular processes such as apoptosis, angiogenesis, migration, and cell cycle progression. It achieves this by interacting with various signaling pathways and proteins. In the current review, the molecular targets of Luteolin as it exerts its anticancer properties, the combination therapy that includes Luteolin with other flavonoids or chemotherapeutic drugs, and the nanodelivery strategies for Luteolin are described for several cancer types.

Research Progress with Luteolin as an Anti-Tumor Agent

In this review, we outline the new expertise and research progress with luteolin as an antitumor agent, and clarify the related results from the aspects of tumor proliferation, apoptosis, invasion, metastasis, sensitivity to radiotherapy and chemotherapy, angiogenesis, and immunotherapy. In recent years, with the development of medical technology, the early detection rate of tumors has increased significantly. However, the number of cancer patients remains high. Therefore, a new and reasonably effective tumor therapeutic drug is urgently demanded. Luteolin, a flavonoid and widespread in nature, attracts more and more attention due to its universal biological utility, especially in the study of antitumor activity. This article reviews the work published in the past 20 years on the role and mechanism of luteolin as an antitumor agent, showing that this compound has a variety of effects for antitumor treatment by acting on different cytokines. Although clinical studies have not yet been widely carried out, a series of basic studies have confirmed that luteolin is a reasonably effective antineoplastic agent or anticancer adjuvant. Besides, derivatives of luteolin have good application prospects.

Recent updates on anticancer mechanisms of polyphenols

In today’s scenario, when cancer cases are increasing rapidly, anticancer herbal compounds become imperative. Studies on the molecular mechanisms of action of polyphenols published in specialized databases such as Web of Science, Pubmed/Medline, Google Scholar, and Science Direct were used as sources of information for this review. Natural polyphenols provide established efficacy against chemically induced tumor growth with fewer side effects. They can sensitize cells to various therapies and increase the effectiveness of biotherapy. Further pharmacological translational research and clinical trials are needed to evaluate theirs in vivo efficacy, possible side effects and toxicity. Polyphenols can be used to design a potential treatment in conjunction with existing cancer drug regimens such as chemotherapy and radiotherapy.

Role of STAT3 in the initiation, progression, proliferation and metastasis of breast cancer and strategies to deliver JAK and STAT3 inhibitors

INTRODUCTION

Breast cancer (BC) accounts for the majority of cancers among the female population. Anomalous activation of various signaling pathways has become an issue of concern. The JAK-STAT signaling pathway is activated in numerous cancers, including BC. STAT3 is widely involved in BCs, as 40 % of BCs display phosphorylated STAT3. JAK-STAT signaling is crucial for proliferation, survival, metastasis and other cellular events associated with the tumor microenvironment. Hence, targeting this pathway has become an area of interest among researchers.

KEY FINDINGS

This review article focuses on the role of STAT3 in the initiation, proliferation, progression and metastasis of BC. The roles of various phytochemicals, synthetic molecules and biologicals against JAK-STAT and STAT3 in various cancers have been discussed, with special emphasis on BC.

SIGNIFICANCE

JAK and STAT3 are involved in various phases from initiation to metastasis, and targeting this pathway is a promising approach to inhibit the various stages of BC development and to prevent metastasis. A number of phytochemicals and synthetic and biological molecules have demonstrated potential inhibitory effects on JAK and STAT3, thereby paving the way for the development of better therapeutics against BC.

Phosphatidylcholine-Based Nanoemulsions for Paclitaxel and a P-Glycoprotein Inhibitor Delivery and Breast Cancer Intraductal Treatment

In this study, incorporation of the cytotoxic agent paclitaxel and the P-glycoprotein inhibitor elacridar in hyaluronic acid (HA)-modified nanoemulsions was studied for intraductal delivery and breast cancer localized treatment. To improve cytotoxicity, we investigated the incorporation of perillyl alcohol or tributyrin as components of the nanoemulsion oil phase. The nanoemulsions presented size <180 nm and negative zeta potential. Both tributyrin and perillyl alcohol increased nanoemulsion cytotoxicity in MCF-7 cells, but not in MDA-MB-231. However, perillyl alcohol reduced nanoemulsion stability in the presence of the drugs. Concomitant incorporation of paclitaxel and elacridar in HA- and tributyrin-containing nanoemulsions (PE-NETri) increased cytotoxicity and reduced IC50 by 1.6 to 3-fold in MCF-7 and MDA-MB-231 cells compared to the nanoemulsion containing only paclitaxel (P-NE). This nanoemulsion also produced a 3.3-fold reduction in the viability of MDA-MB-231 spheroids. Elacridar incorporated in the nanoemulsion was capable of inhibiting P-glycoprotein in membranes. In vivo intraductal administration of the NE containing HA resulted in a three-fold higher retention of a fluorescent marker compared to a solution or nanoemulsion without HA, demonstrating the importance of HA. The nanoemulsion produced no histological changes in the mammary tissue. These results support the potential applicability of the nanoemulsion for local breast cancer management.

Small Molecule Inhibitors for Hepatocellular Carcinoma: Advances and Challenges

According to data provided by World Health Organization, hepatocellular carcinoma (HCC) is the sixth most common cause of deaths due to cancer worldwide. Tremendous progress has been achieved over the last 10 years developing novel agents for HCC treatment, including small-molecule kinase inhibitors. Several small molecule inhibitors currently form the core of HCC treatment due to their versatility since they would be more easily absorbed and have higher oral bioavailability, thus easier to formulate and administer to patients. In addition, they can be altered structurally to have greater volumes of distribution, allowing them to block extravascular molecular targets and to accumulate in a high concentration in the tumor microenvironment. Moreover, they can be designed to have shortened half-lives to control for immune-related adverse events. Most importantly, they would spare patients, healthcare institutions, and society as a whole from the burden of high drug costs. The present review provides an overview of the pharmaceutical compounds that are licensed for HCC treatment and other emerging compounds that are still investigated in preclinical and clinical trials. These molecules are targeting different molecular targets and pathways that are proven to be involved in the pathogenesis of the disease.

Effects of Luteolin on Human Breast Cancer Using Gene Expression Array: Inferring Novel Genes

Taraxacum officinale (dandelion) is often used in traditional Chinese medicine for the treatment of cancer; however, the downstream regulatory genes and signaling pathways mediating its effects on breast cancer remain unclear. The present study aimed to explore the effects of luteolin, the main biologically active compound of T. officinale, on gene expression profiles in MDA-MB-231 and MCF-7 breast cancer cells. The results revealed that luteolin effectively inhibited the proliferation and motility of the MDA-MB-231 and MCF-7 cells. The mRNA expression profiles were determined using gene expression array analysis and analyzed using a bioinformatics approach. A total of 41 differentially expressed genes (DEGs) were found in the luteolin-treated MDA-MB-231 and MCF-7 cells. A Gene Ontology analysis revealed that the DEGs, including AP2B1, APP, GPNMB and DLST, mainly functioned as oncogenes. The human protein atlas database also found that AP2B1, APP, GPNMB and DLST were highly expressed in breast cancer and that AP2B1 (cut-off value, 75%) was significantly associated with survival rate (p = 0.044). In addition, a Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that the DEGs were involved in T-cell leukemia virus 1 infection and differentiation. On the whole, the findings of the present study provide a scientific basis that may be used to evaluate the potential benefits of luteolin in human breast cancer. Further studies are required, however, to fully elucidate the role of the related molecular pathways.

Luteolin binds Src, promotes STAT3 protein ubiquitination and exerts anti-melanoma effects in cell and mouse models

Signal transducer and activator of transcription 3 (STAT3) has been proposed as a target for melanoma prevention. Luteolin, a bioactive flavonoid abundant inmedicinal herbs, has been reported to have anti-melanoma activity in vitro. However, its in vivo anti-melanoma effects and underlying mechanisms have not been fully elucidated. In this study, ten cell lines and two mouse models (B16F10 allograft and A375 xenograft models) were used for assessing the in vitro and in vivo anti-melanoma effects of luteolin. A STAT3 over-activated stable A375 cell line was used to determine the contribution of STAT3 signaling in luteolin's anti-melanoma effects. Results showed that luteolin dose-dependently reduced viability of melanoma cells. Luteolin also induced apoptosis in, and suppressed migration and invasion of, A375 and B16F10 melanoma cells. Mechanistically, luteolin inhibited phosphorylation of STAT3 and Src (an upstream kinase of STAT3), accelerated ubiquitin-proteasome pathway-mediated STAT3 degradation, and downregulated the expression of STAT3-targeted genes involved in cell survival and invasion in melanoma cells. Molecular modelling and surface plasmon resonance imaging showed that luteolin stably bound to the protein kinase domain of Src. Animal studies demonstrated that prophylactic administration of luteolin restrained melanoma growth and Src/STAT3 signaling in both A375 and B16F10 melanoma-bearing mice. Moreover, luteolin's anti-melanoma effects were diminished by STAT3 over-activation in A375 cells. Our findings indicate that luteolin inhibits STAT3 signaling by suppressing STAT3 activation and promoting STAT3 protein degradation in melanoma cells, thereby exhibiting anti-melanoma effects. This study provides further pharmacological groundwork for developing luteolin as a chemopreventive agent against melanoma.

JAK-STAT core cancer pathway: An integrative cancer interactome analysis

Through a comprehensive review and in silico analysis of reported data on STAT-linked diseases, we analysed the communication pathways and interactome of the seven STATs in major cancer categories and proposed rational targeting approaches for therapeutic intervention to disrupt critical pathways and addictions to hyperactive JAK/STAT in neoplastic states. Although all STATs follow a similar molecular activation pathway, STAT1, STAT2, STAT4 and STAT6 exert specific biological profiles associated with a more restricted pattern of activation by cytokines. STAT3 and STAT5A as well as STAT5B have pleiotropic roles in the body and can act as critical oncogenes that promote many processes involved in cancer development. STAT1, STAT3 and STAT5 also possess tumour suppressive action in certain mutational and cancer type context. Here, we demonstrated member-specific STAT activity in major cancer types. Through systems biology approaches, we found surprising roles for EGFR family members, sex steroid hormone receptor ESR1 interplay with oncogenic STAT function and proposed new drug targeting approaches of oncogenic STAT pathway addiction.

Influence of Olive Oil and Its Components on Breast Cancer: Molecular Mechanisms

Breast cancer is the most frequent malignant neoplasia and a leading cause of mortality in women worldwide. The Mediterranean diet has been proposed as a healthy dietary pattern with protective effects in several chronic diseases, including breast cancer. This diet is characterized by the consumption of abundant plant foods and olive oil as the principal source of fat, which is considered one of the main components with potential antioxidant, anti-inflammatory and anticancer effects. Extra-virgin olive oil (EVOO) has several bioactive compounds, mainly including monounsaturated fatty acids, triterpenes and polyphenols, such as phenolic alcohols (e.g., hydroxytyrosol), secoiridoids (e.g., oleuropein and oleocanthal), lignans (e.g., pinoresinol) or flavonoids (e.g., luteolin). While epidemiological evidence is still limited, experimental in vivo and in vitro data have shown a protective effect of this oil and its compounds on mammary carcinogenesis. Such effects account through complex and multiple mechanisms, including changes in epigenetics, transcriptome and protein expression that modulate several signaling pathways. Molecular targets of EVOO compounds have a role in the acquisition of cancer hallmarks. Although further research is needed to elucidate their beneficial effects on human prevention and progression of the disease, evidence points to EVOO in the context of the Mediterranean diet as a heathy choice, while EVOO components may be promising adjuvants in anticancer strategies.

Psoralen-loaded polymeric lipid nanoparticles combined with paclitaxel for the treatment of triple-negative breast cancer

Background: Chemotherapeutic drugs are associated with toxic effects. Metastasis is the leading cause of death in breast cancer patients. Aim: To evaluate the antitumor effect of paclitaxel (PTX) combined with psoralen-loaded polymeric lipid nanoparticles (PSO-PLNs) in triple-negative breast cancer. Methods: After treatment of samples, cell viability, apoptosis, migration, invasion, expression of proteins in the IRAK1/NF-κB/FAK signal pathway, biodistribution and pathological characteristics were detected. Results: Compared with the control group, the PTX + PSO-PLNs group showed increased apoptosis and reduced migration, invasion and expression of phosphorylated IRAK1 and NF-κB, with significant inhibition of tumor growth and lung metastases and no obvious toxicity. Conclusion: Combined administration of PTX and PSO-PLNs exerted a synergistic effect and significantly inhibited the growth and metastasis of triple-negative breast cancer.

Luteolin Attenuates Diabetic Nephropathy through Suppressing Inflammatory Response and Oxidative Stress by Inhibiting STAT3 Pathway

BACKGROUND

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease (ESRD). DN has many pathological changes, but tubular injury is considered to be a crucial pathological feature and plays a key role in the progression of DN. Accumulating studies have confirmed that Luteolin (3,4,5,7-tetrahydroxyflavone, Lut) possesses anti-inflammatory and antioxidant activities, which may play a role in kidney protection in DN.

OBJECTIVES

This paper described the effects of Lut on appropriated tubular injury in the kidneys of db/db mice and searched the possible mechanisms underlying the kidney protection effect in DN.

METHODS

Twelve-week-old male C57BL/6 J db/db and C57BL/6 J db/m mice were used for the animal experiments. They were organized into the following five groups for the animal experiments: a db/m group (control, n=6); a db/db group(n=8) ; a db/db group receiving Lut (10 mg/kg/day, n=8)treatment by oral gavage; a db/db group receiving stattic (a selective STAT3 inhibitor,50 mg/Kg/day, n=8) treatment by oral gavage and a db/db group receiving both stattic and Lut treatment by oral gavage.

RESULTS

In this study, we found that Lut might ameliorate glomerular sclerosis and interstitial fibrosis in DN mouse models through inhibiting the inflammatory response and oxidative stress. And it might play its biological function mainly through repressing the STAT3 activation.

CONCLUSIONS

Lut attenuates DN mainly via suppression of inflammatory response and oxidative response. STAT3 pathway is the potential target, which ultimately reduces renal fibrosis and delays the progress of DN.

Pharmacological Effects of Polyphenol Phytochemicals on the JAK-STAT Signaling Pathway

The JAK-STAT signaling pathway is a common pathway of many cytokine signal transductions, closely related to cell proliferation, apoptosis, differentiation, and inflammatory response. It is essential for inhibiting the inflammatory response, initiating innate immunity, and coordinating adaptive immune mechanisms. Owing to the nature of this pathway and its potential cross-epitopes with multiple alternative pathways, the long-term efficacy of monotherapy-based adaptive targeting therapy is limited, and the majority of drugs targeting STATs are still in the preclinical phase. Meanwhile, curcumin, quercetin, and several kinds of plant polyphenol chemicals play roles in multiple sites of the JAK-STAT pathway to suppress abnormal activation. Polyphenol compounds have shown remarkable effects by acting on the JAK-STAT pathway in anti-inflammatory, antitumor, and cardiovascular disease control. This review summarizes the pharmacological effects of more than 20 kinds of phytochemicals on JAK-STAT signaling pathway according to the chemical structure of polyphenolic phytochemicals.

Ouabain Induces DNA Damage in Human Osteosarcoma U-2 OS Cells and Alters the Expression of DNA Damage and DNA Repair-associated Proteins

BACKGROUND/AIM

Ouabain, isolated from natural plants, exhibits anticancer activities; however, no report has presented its mechanism of DNA damage induction in human osteosarcoma cancer cells in vitro. The aim of this study was to investigate whether ouabain induces DNA damage and repair, accompanied with molecular pathways in human osteosarcoma cancer U-2 OS cells in vitro.

MATERIALS AND METHODS

The percentage of viable cell number was measured by flow cytometric assay; DNA damage was assayed by DAPI staining, comet assay, and agarose gel electrophoresis. DNA damage and repair associated protein expressions were assayed by western blotting assays.

RESULTS

Ouabain reduced total cell viability, induced chromatin condensation, DNA fragmentation, and DNA damage in U-2 OS cells. Ouabain increased p-ATM^Ser1981, p-ATR^Ser428, and p53 at 2.5-10 μM, increased p-p53^Ser15 at 10 μM; however, it decreased p-MDM2^Ser166 at 2.5-10 μM. Ouabain increased p-H2A.X^Ser139, MDC-1, and PARP at 2.5-10 μM and BRCA1 at 5-10 μM; however, it decreased DNA-PK and MGMT at 2.5-10 μM in U-2 OS cells at 48 h treatment. Ouabain promoted expression and nuclear translocation of p-H2A.X^Ser139 in U-2 OS cells and this was confirmed by confocal laser microscopy.

CONCLUSION

Ouabain reduced total viable cell number through triggering DNA damage and altering the protein expression of DNA damage and repair system in U-2 OS cells in vitro.

Development and Evaluations of Transdermally Delivered Luteolin Loaded Cationic Nanoemulsion: In Vitro and Ex Vivo Evaluations

Introduction: Luteolin (LUT) is natural flavonoid with multiple therapeutic potentials and is explored for transdermal delivery using a nanocarrier system. LUT loaded cationic nanoemulsions (CNE1–CNE9) using bergamot oil (BO) were developed, optimized, and characterized in terms of in vitro and ex vivo parameters for improved permeation. Materials and methods: The solubility study of LUT was carried out in selected excipients, namely BO, cremophor EL (CEL as surfactant), labrasol (LAB), and oleylamine (OA as cationic charge inducer). Formulations were characterized with globular size, polydispersity index (PDI), zeta potential, pH, and thermodynamic stability studies. The optimized formulation (CNE4) was selected for comparative investigations (% transmittance as %T, morphology, chemical compatibility, drug content, in vitro % drug release, ex vivo skin permeation, and drug deposition, DD) against ANE4 (anionic nanoemulsion for comparison) and drug suspension (DS). Results: Formulations such as CNE1–CNE9 and ANE4 (except CNE6 and CNE8) were found to be stable. The optimized CNE4 based on the lowest value of globular size (112 nm), minimum PDI (0.15), and optimum zeta potential (+26 mV) was selected for comparative assessment against ANE4 and DS. The %T values of CNE1–CNE9 were found to be ˃95% and CEL content slightly improved the %T value. The spherical CNE4 was compatible with excipients and showed % total drug content in the range of 97.9–99.7%. In vitro drug release values from CNE4 and ANE4 were significantly higher than DS. Moreover, permeation flux (138.82 ± 8.4 µg/cm²·h), enhancement ratio (8.23), and DD (10.98%) were remarkably higher than DS. Thus, ex vivo parameters were relatively high as compared to DS which may be attributed to nanonization, surfactant-mediated reversible changes in skin lipid matrix, and electrostatic interaction of nanoglobules with the cellular surface. Conclusion: Transdermal delivery of LUT can be a suitable alternative to oral drug delivery for augmented skin permeation and drug deposition.

Thieno[2,3-b]Pyridine Derivative Targets Epithelial, Mesenchymal and Hybrid CD15s+ Breast Cancer Cells

The adhesion of cancer cells to vascular endothelium is a critical process in hematogenous metastasis and might be similar to the recruitment of leukocytes at the site of inflammation. It is mediated by E-selectin and its ligands, of which the most stereospecific is a glycoconjugate sialyl Lewis x (CD15s), which may be expressed as an oligosaccharide branch of the CD44 glycoprotein, as well as a self-contained glycosphingolipid. It is also known that increased sialylation of glycoconjugates is a feature of malignant cells. The aim of the study was to analyse the effect of a novel thieno[2,3-b]pyridine, compound 1, in MDA-MB-231 triple-negative breast cancer cells (TNBCs) upon CD15s and CD44 expression in different cell subpopulations using flow cytometry. CD15s expression was compared between mesenchymal-like cancer stem cells (CSC, CD44⁺CD24⁻), epithelial cells without CD44 (CD44⁻CD24⁺ and CD44⁻CD24⁻), and CD44⁺CD24⁺ cells that exhibit mesenchymal and epithelial features. In addition, expression of CD44 in CD15s⁺CSC and CD15s⁻CSC was determined. Compound 1 significantly decreased the percentage of CD15s⁺CSC, CD15s⁺CD44⁺CD24⁺, and CD15s⁺CD44⁻ subpopulations, as well as the expression of CD15s in CD44⁺CD24⁺ and CD44⁻ cells, and therefore shows potential as a treatment for TNBC.

Targeting LIMK1 with luteolin inhibits the growth of lung cancer in vitro and in vivo

Lung cancer is the leading cause of cancer‐related deaths. LIM domain kinase (LIMK) 1 is a member of serine/threonine kinase family and highly expressed in various cancers. Luteolin, a polyphenolic plant flavonoid, has been reported to suppress tumour proliferation through inducing apoptosis and autophagy via MAPK activation in glioma. However, the mechanism of luteolin on suppressing lung cancer growth is still unclear. We found that luteolin targeted LIMK1 from the in silico screening and significantly inhibited the LIMK1 kinase activity, which was confirmed with pull‐down binding assay and computational docking models. Treatment with luteolin inhibited lung cancer cells anchorage‐independent colony growth and induced apoptosis and cell cycle arrest at G1 phase. Luteolin also decreased the expression of cyclin D1 and increased the levels of cleaved caspase‐3 by down‐regulating LIMK1 signalling related targets, including p‐LIMK and p‐cofilin. Furthermore, luteolin suppressed the lung cancer patient‐derived xenograft tumour growth by decreasing Ki‐67, p‐LIMK and p‐cofilin expression in vivo. Taken together, these results provide insight into the mechanism that underlies the anticancer effects of luteolin on lung cancer, which involved in down‐regulation of LIMK1 and its interaction with cofilin. It also provides valuable evidence for translation towards lung cancer clinical trials with luteolin.

Luteolin and cancer metastasis suppression: focus on the role of epithelial to mesenchymal transition

Epithelial to mesenchymal transition (EMT) is a physiological process that assumes a primary role in the induction of cancer metastasis. This results in increased cell renewal, and resistance to cell death and therapies. EMT, therefore, represents an effective strategy for regulating cancerous cell activity. A need for efficacy and low cytotoxicity epithelial to mesenchymal transition modifying drugs has led to the investigational testing of the efficacy of plethora of different groups of phytonutrients. Luteolin is a natural flavonoid inhibits the growth of cancer cells by various mechanisms, such as the stimulation of cancer cell apoptosis, cell cycle arrest, inhibition of cell replication, tumor growth, improvement of drug resistance, prevention of cancer cell intrusiveness and metastasis. This review article focuses on the anti-cancer and anti-metastatic potential of luteolin targeting various transcription factors, markers and signaling pathways associated with the repression of epithelial to mesenchymal transition.

Effect of luteolin on apoptosis and vascular endothelial growth factor in human choroidal melanoma cells

AIM

To investigate the effects of luteolin on apoptosis, the cell cycle, and the expression and secretion of vascular endothelial growth factor (VEGF) in human choroidal melanoma cells (C918 and OCM-1).

METHODS

C918 and OCM-1 cells cultured in vitro were treated with various concentrations of luteolin (0, 5, 10, 15 µmol/L). Cell growth was observed with an inverted microscope, and cell cycle arrest was detected by propidium iodide (PI) staining using flow cytometry. Apoptosis was detected by Hoechst33342 staining, and apoptosis rate was determined by Annexin V-FITC/PI experiments using flow cytometry. The expression of apoptosis-related proteins Bcl-2, Bax and VEGF was analyzed using Western blots. The levels of VEGF secreted by the cells into the supernatant was analyzed using ELISA.

RESULTS

After treating with 5 to 15 µmol/L luteolin for 48h, the fusion degree of C918 and OCM-1 cells decreased, and more floating apoptotic cells appeared. Luteolin treatment increased the G0-G1 phase ratio of the C918 and OCM-1 cells, blocked cell cycle progression, and increased the apoptosis rate of the C918 and OCM-1 cells. Western blot showed that luteolin decreased the expression of Bcl-2 and VEGF in the C918 and OCM-1 cells and increased the expression of Bax protein. The ELISA results showed that 10 to 15 µmol/L luteolin decreased the cell secretion of VEGF.

CONCLUSION

Luteolin may induce apoptosis by regulating the levels of apoptosis-related proteins in C918 and OCM-1 cells. Luteolin can induce cell cycle arrest, decrease the expression of VEGF.

A Network Pharmacology Study on the Molecular Mechanisms of FDY003 for Breast Cancer Treatment

Herbal medicines have drawn considerable attention with regard to their potential applications in breast cancer (BC) treatment, a frequently diagnosed malignant disease, considering their anticancer efficacy with relatively less adverse effects. However, their mechanisms of systemic action have not been understood comprehensively. Based on network pharmacology approaches, we attempted to unveil the mechanisms of FDY003, an herbal drug comprised of Lonicera japonica Thunberg, Artemisia capillaris Thunberg, and Cordyceps militaris, against BC at a systemic level. We found that FDY003 exhibited pharmacological effects on human BC cells. Subsequently, detailed data regarding the biochemical components contained in FDY003 were obtained from comprehensive herbal medicine-related databases, including TCMSP and CancerHSP. By evaluating their pharmacokinetic properties, 18 chemical compounds in FDY003 were shown to be potentially active constituents interacting with 140 BC-associated therapeutic targets to produce the pharmacological activity. Gene ontology enrichment analysis using g:Profiler indicated that the FDY003 targets were involved in the modulation of cellular processes, involving the cell proliferation, cell cycle process, and cell apoptosis. Based on a KEGG pathway enrichment analysis, we further revealed that a variety of oncogenic pathways that play key roles in the pathology of BC were significantly enriched with the therapeutic targets of FDY003; these included PI3K-Akt, MAPK, focal adhesion, FoxO, TNF, and estrogen signaling pathways. Here, we present a network-perspective of the molecular mechanisms via which herbal drugs treat BC.

Protective Effects of Curcumin Against Paclitaxel-Induced Spinal Cord and Sciatic Nerve Injuries in Rats

Paclitaxel (PTX) is an antineoplastic agent commonly used in the treatment of solid tumors and is known to cause dose-limiting peripheral neurotoxicity. This study was performed to evaluate the protective effect of curcumin (CUR) against PTX-induced spinal cord and sciatic nerve injuries in rats. The rats were administered PTX (2 mg/kg, BW) intraperitoneally for the first 5 consecutive days followed by administration of CUR (100 and 200 mg/kg, BW daily in corn oil) orally for 10 days. Our results showed that CUR significantly reduced mRNA expression levels of NF-κB, TNF-α, IL-6, iNOS and GFAP whereas caused an increase in levels of Nrf2, HO-1 and NQO1 in the spinal cord and sciatic nerve of PTX-induced rats. In addition, CUR suppressed the activation of apoptotic and autophagic pathways by increasing Bcl-2 and Bcl-xL, and decreasing p53, caspase-3, Apaf-1, LC3A, LC3B and beclin-1 mRNA expression levels. The results showed that CUR also maintained the spinal cord and sciatic nerve histological architecture and integrity by both LFB staining and H&E staining. Immunohistochemical expressions of 8-OHdG, caspase-3 and LC3B in the PTX-induced spinal cord tissue were decreased after administration of CUR. Taken together, our findings demonstrated that CUR has protective effects on PTX-induced spinal cord and sciatic nerve injuries in rats.

Transcriptome modulation following administration of luteolin to bleomycin-etoposide-cisplatin chemotherapy on rat LC540 tumor Leydig cells

Leydig cell tumours represent 1%-3% of all cases of testicular tumours in men. Such tumours respond poorly to radiation or chemotherapy, including bleomycin-etoposide-cisplatin (BEP) combinatorial therapy. In this study, we investigated an alternative approach involving luteolin to improve the efficacy of chemotherapy. LC540 tumour Leydig cells were treated with BEP (bleomycin 40 µg/ml, etoposide 4 µg/ml, cisplatin 8 µg/ml) and/or luteolin 10 µM for comparison with DMSO-treated cells. We performed a transcriptome analysis using RNA-Seq to characterise changes in biological processes and signalling pathways. Treatments of LC540 tumour Leydig cells with luteolin significantly decreased the expression of genes involved in cholesterol biosynthesis, while increasing the expression of genes related to glutathione conjugation (p < .05). Genes being significantly upregulated in response to BEP treatment were involved in the response to toxic substances and transcriptional regulation. Oppositely, genes being significantly downregulated by BEP treatment were enriched for intracellular signal transduction, cell migration, cell adhesion, reproductive system development and cholesterol biosynthesis. BEP chemotherapy proved to be effective in increasing gene expression related to apoptosis of tumour Leydig cells. However, addition of luteolin to BEP treatment had no other effects on biological processes or pathways related to cancer treatment.

Luteolin mediated targeting of protein network and microRNAs in different cancers: Focus on JAK-STAT, NOTCH, mTOR and TRAIL-mediated signaling pathways

There has always been a keen interest of basic and clinical researchers to search for cancer therapeutics having minimum off-target effects and maximum anticancer activities. In accordance with this approach, there has been an explosion in the field of natural products research in the past few decades because of extra-ordinary list of natural extracts and their biologically and pharmacologically active constituents having significant medicinal properties. Apparently, luteolin-mediated anticancer effects have been investigated in different cancers but there is superfluousness of superficial data. Generalized scientific evidence encompassing apoptosis, DNA damage and anti-inflammatory effects has been reported extensively. However, how luteolin modulates deregulated oncogenic pathways in different cancers has not been comprehensively uncovered. In this review we have attempted to focus on cutting-edge research which has unveiled remarkable abilities of luteolin to modulate deregulated oncogenic pathways in different cancers. We have partitioned the review into various sections to separately discuss advancements in therapeutic targeting of oncogenic protein networks. We have provided detailed mechanistic insights related to JAK-STAT signaling and summarized how luteolin inhibited STAT proteins to inhibit STAT-driven gene network. We have also individually analyzed Wnt/β-catenin and NOTCH pathway and how luteolin effectively targeted these pathways. Mapping of the signaling landscape has revealed that NOTCH pathway can be targeted therapeutically. NOTCH pathway was noted to be targeted by luteolin. We have also conceptually analyzed how luteolin restored TRAIL-induced apoptosis in resistant cancers. Luteolin induced an increase in pro-apoptotic proteins and efficiently inhibited anti-apoptotic proteins to induce apoptosis. Luteolin mediated regulation of non-coding RNAs is an exciting and emerging facet. Excitingly, there is sequential and systematic accumulation of clues which have started to shed light on intricate regulation of microRNAs by luteolin in different cancers. Collectively, sophisticated information will enable us to develop a refined understanding of the multi-layered regulation of signaling pathways and non-coding RNAs by luteolin in different cancers.

Comparative studies of two vegetal extracts from Stokesia laevis and Geranium pratense: polyphenol profile, cytotoxic effect and antiproliferative activity

In this study, two ethanolic extracts, from Stokesia aster (Slae26) and Geranium pratense (Gpre36) respectively, were evaluated in order to assess the cytotoxic activity and potential antiproliferative activity upon the nontumorigenic human epithelial cell line derived from the mammary gland (MCF-12A) and the human breast tumor cell line (BT-20). The selection of the plant species was done on the basis of their chemical composition, specifically combinations of luteolin derivatives with caffeic and gallic acid derivatives. Therefore, the S. laevis ethanolic extract proved its capacity to inhibit the viability of both normal and tumor breast cell lines (i.e., up to 90% cell viability inhibition, IC50 = 42 µg/mL). On the contrary, the G. pratense ethanolic extract proved weak stimulatory effects on the viability of the two human breast cell lines studied. The obtained results were discussed in the contexts of computational studies and drug-likeness bioactivity of seven common luteolin derivatives: luteolin, luteolin-7-O-glucoside/cynaroside, luteolin-5-O-glucoside/galuteolin, luteolin-6-C-glucoside/isoorientin, luteolin-8-C-glucoside/orientin, luteolin-3′,4′-di-O-glucoside and luteolin-7,3′-di-O-glucoside. Computational studies have revealed that the hydrophilic behavior of luteolin derivatives (log P values) does not follow other tested parameters (e.g., polar surface area values), possibly explaining different efficacy concerning the biological properties in vitro. These predictions could be a starting point for studies on the biochemical mechanism by which luteolin derivatives induce biological effects.

Mapping Pharmacological Network of Multi-Targeting Litchi Ingredients in Cancer Therapeutics

Considerable pharmacological studies have demonstrated that the extracts and ingredients from different parts (seeds, peels, pulps, and flowers) of Litchi exhibited anticancer effects by affecting the proliferation, apoptosis, autophagy, metastasis, chemotherapy and radiotherapy sensitivity, stemness, metabolism, angiogenesis, and immunity via multiple targeting. However, there is no systematical analysis on the interaction network of “multiple ingredients-multiple targets-multiple pathways” anticancer effects of Litchi. In this study, we summarized the confirmed anticancer ingredients and molecular targets of Litchi based on published articles and applied network pharmacology approach to explore the complex mechanisms underlying these effects from a perspective of system biology. The top ingredients, top targets, and top pathways of each anticancer function were identified using network pharmacology approach. Further intersecting analyses showed that Epigallocatechin gallate (EGCG), Gallic acid, Kaempferol, Luteolin, and Betulinic acid were the top ingredients which might be the key ingredients exerting anticancer function of Litchi, while BAX, BCL2, CASP3, and AKT1 were the top targets which might be the main targets underling the anticancer mechanisms of these top ingredients. These results provided references for further understanding and exploration of Litchi as therapeutics in cancer as well as the application of “Component Formula” based on Litchi’s effective ingredients.

Casticin Induces DNA Damage and Affects DNA Repair Associated Protein Expression in Human Lung Cancer A549 Cells (Running Title: Casticin Induces DNA Damage in Lung Cancer Cells)

Casticin was obtained from natural plants, and it has been shown to exert biological functions; however, no report concerns the induction of DNA damage and repair in human lung cancer cells. The objective of this study was to investigate the effects and molecular mechanism of casticin on DNA damage and repair in human lung cancer A549 cells. Cell viability was determined by flow cytometric assay. The DNA damage was evaluated by 4',6-diamidino-2-phenylindole (DAPI) staining and electrophoresis which included comet assay and DNA gel electrophoresis. The protein levels associated with DNA damage and repair were analyzed by western blotting. The expression and translocation of p-H2A.X were observed by confocal laser microscopy. Casticin reduced total viable cell number and induced DNA condensation, fragmentation, and damage in A549 cells. Furthermore, casticin increased p-ATM at 6 h and increased p-ATR and BRCA1 at 6-24 h treatment but decreased p-ATM at 24-48 h, as well as decreased p-ATR and BRCA1 at 48 h. Furthermore, casticin decreased p-p53 at 6-24 h but increased at 48 h. Casticin increased p-H2A.X and MDC1 at 6-48 h treatment. In addition, casticin increased PARP (cleavage) at 6, 24, and 48 h treatment, DNA-PKcs and MGMT at 48 h in A549 cells. Casticin induced the expressions and nuclear translocation of p-H2AX in A549 cells by confocal laser microscopy. Casticin reduced cell number through DNA damage and condensation in human lung cancer A549 cells.

Therapeutic and preventive properties of honey and its bioactive compounds in cancer: an evidence-based review

Despite the much improved therapeutic approaches for cancer treatment that have been developed over the past 50 years, cancer remains a major cause of mortality globally. Considerable epidemiological and experimental evidence has demonstrated an association between ingestion of food and nutrients with either an increased risk for cancer or its prevention. There is rising interest in exploring agents derived from natural products for chemoprevention or for therapeutic purposes. Honey is rich in nutritional and non-nutritional bioactive compounds, as well as in natural antioxidants, and its potential beneficial function in human health is becoming more evident. A large number of studies have addressed the anti-cancer effects of different types of honey and their phenolic compounds using in vitro and in vivo cancer models. The reported findings affirm that honey is an agent able to modulate oxidative stress and has anti-proliferative, pro-apoptotic, anti-inflammatory, immune-modulatory and anti-metastatic properties. However, despite its reported anti-cancer activities, very few clinical studies have been undertaken. In the present review, we summarise the findings from different experimental approaches, including in vitro cell cultures, preclinical animal models and clinical studies, and provide an overview of the bioactive profile and bioavailability of the most commonly studied honey types, with special emphasis on the chemopreventive and therapeutic properties of honey and its major phenolic compounds in cancer. The implications of these findings as well as the future prospects of utilising honey to fight cancer will be discussed.

Inhibition of Tyrosine-Phosphorylated STAT3 in Human Breast and Lung Cancer Cells by Manuka Honey is Mediated by Selective Antagonism of the IL-6 Receptor

Aberrantly high levels of tyrosine-phosphorylated signal transducer and activator of transcription 3 (p-STAT3) are found constitutively in ~50% of human lung and breast cancers, acting as an oncogenic transcription factor. We previously demonstrated that Manuka honey (MH) inhibits p-STAT3 in breast cancer cells, but the exact mechanism remained unknown. Herein, we show that MH-mediated inhibition of p-STAT3 in breast (MDA-MB-231) and lung (A549) cancer cell lines is accompanied by decreased levels of gp130 and p-JAK2, two upstream components of the IL-6 receptor (IL-6R) signaling pathway. Using an ELISA-based assay, we demonstrate that MH binds directly to IL-6Rα, significantly inhibiting (~60%) its binding to the IL-6 ligand. Importantly, no evidence of MH binding to two other cytokine receptors, IL-11Rα and IL-8R, was found. Moreover, MH did not alter the levels of tyrosine-phosphorylated or total Src family kinases, which are also constitutively activated in cancer cells, suggesting that signaling via other growth factor receptors is unaffected by MH. Binding of five major MH flavonoids (luteolin, quercetin, galangin, pinocembrin, and chrysin) was also tested, and all but pinocembrin could demonstrably bind IL-6Rα, partially (30-35%) blocking IL-6 binding at the highest concentration (50 μM) used. In agreement, each flavonoid inhibited p-STAT3 in a dose-dependent manner, with estimated IC50 values in the 3.5-70 μM range. Finally, docking analysis confirmed the capacity of each flavonoid to bind in an energetically favorable configuration to IL-6Rα at a site predicted to interfere with ligand binding. Taken together, our findings identify IL-6Rα as a direct target of MH and its flavonoids, highlighting IL-6R blockade as a mechanism for the anti-tumor activity of MH, as well as a viable therapeutic target in IL-6-dependent cancers.

Zinc promotes prostate cancer cell chemosensitivity to paclitaxel by inhibiting epithelial-mesenchymal transition and inducing apoptosis

BACKGROUND

Paclitaxel (PTX) is a first-line chemotherapeutic drug for the treatment of prostate cancer. However, most patients develop resistance and metastasis, and thus new therapeutic approaches are urgently required. Recent studies have identified widespread anti-tumor effects of zinc (Zn) in various tumor cell lines, especially prostate cancer cells. In this study, we examined the effects of Zn as an adjuvant to PTX in prostate cancer cells.

METHODS

PC3 and DU145 cells were treated with different concentrations of Zn and/or PTX. MTT assay was used to detect cell viability. Real-time cell analysis (RTCA) and microscopy were used to observe morphological changes in cells. Western blotting was used to detect the expression of epithelial-mesenchymal transition (EMT)-related proteins. qPCR (reverse transcription-polymerase chain reaction) was used to examine changes in TWIST1 mRNA levels. Cell invasion and migration were detected by scratch and transwell assays. shRNA against TWIST1 was used to knockdown TWIST1. Colony formation assay was used to detect cell proliferation, while Annexin V and propidium iodide (PI) staining was used to detect cell apoptosis.

RESULTS

Zn and PTX increased proliferation inhibition in a dose- and time-dependent manner in prostate cancer cells, while Zn increased prostate cancer cell chemosensitivity to PTX. Combined Zn and PTX inhibited prostate cancer cell invasion and migration by downregulating the expression of TWIST1. Furthermore, knockdown of TWIST1 increased the sensitivity of prostate cancer cells to PTX. In addition, Zn and PTX reduced cell proliferation and induced apoptosis in prostate cancer cells.

CONCLUSIONS

Our results demonstrated that Zn and PTX combined therapy inhibits EMT by reducing the expression of TWIST1, which reduces the invasion and migration of prostate cancer cells. SiTWIST1 increased the sensitivity of prostate cancer cells to PTX. In addition, with prolonged treatment, Zn and PTX inhibited proliferation and led to prostate cancer cell apoptosis. Therefore, Zn may be a potential adjuvant of PTX in treating prostate cancer and combined treatment may offer a promising therapeutic strategy for prostate cancer.

Luteolin suppresses tumor proliferation through inducing apoptosis and autophagy via MAPK activation in glioma

PURPOSE

Glioma is a malignant tumor that originates in the brain and spine and is difficult to be completely removed. Though glioma patients receive active treatment, the survival rate is still poor. Therefore, it is urgent to discover a new medicine to treat glioma patients in order to improve the survival rate. In this study, we explored the anticancer effect and the potential mechanism of luteolin on glioma in vitro.

MATERIALS AND METHODS

Cell viability was determined by Cell Counting Kit-8 (CCK-8) assay. Fluorescent microscopy and flow cytometry analysis were used to determine the cellular apoptosis. Western blot analysis was performed to explore the changes in protein expression. Quantitative reverse transcription-PCR (qRT-PCR) analysis was utilized to evaluate the expression level of the tumor suppressor miR-124-3p.

RESULTS

CCK-8 assays indicated that luteolin significantly inhibited glioma cell proliferation in a time- and dose-dependent manner. Fluorescent microscopy and flow cytometry analysis confirmed that luteolin induced glioma cell apoptosis. Western blot analysis showed that luteolin induced cellular apoptosis in glioma cells via MAPK activation (JNK, ERK, and p38). Luteolin stimulated the death receptor (FADD) to regulate the apoptosis proteins (Caspase-8, Caspase-3, and PARP). Luteolin increased the expression levels of LC3B II/I and downregulated the level of p62 that promotes cell autophagy. Finally, qRT-PCR confirmed that luteolin upregulated the expression levels of miR-124-3p.

CONCLUSION

These findings illustrate that luteolin may be a potential drug for glioma treatment.

Apoptosis induced by luteolin in breast cancer: Mechanistic and therapeutic perspectives

BACKGROUND

Breast cancer is worldwide commonly found malignancy in women and effective treatment is regarded as a huge clinical challenge even in the presence of several options. Extensive literature is available that demonstrating polyphenols, the richly introduce phytopharmaceuticals as anticancer agents. Among these polyphenols, resveratrol, silibinin, quercetin, genistein, curcumin reported to have an awesome potential against breast cancer. However, till now no comprehensive survey found about the anticarcinogenic properties of luteolin against breast cancer.

SCOPE AND APPROACH

This review targeted the available literature on luteolin in the treatment of breast cancer, effects in combination with other anticancer drugs with possible mechanisms.

KEY FINDINGS AND CONCLUSION

An outstanding therapeutic potential of luteolin in the treatment of breast cancer has been recorded not just as a chemopreventive and chemotherapeutic agent yet complemented by its synergistic effects with other anticancer therapies such as cyclophosphamide, doxorubicin, and NSAID such as celecoxib, and possible underlying mechanisms. Ideally, this review will open new dimensions for luteolin as an effective and safe therapeutic agent in diminishing breast cancer.

Ameliorative effects of luteolin against endometriosis progression in vitro and in vivo

Endometriosis is a common gynecological disease in reproductive-aged women. Generally, accumulation of backflow and debris of endometrial tissue develops into a lesion outside of the endometrium, inducing severe pelvic pain and infertility in some patients. Hormone therapy and surgery are the main treatments available, but various therapeutic phytochemicals are being reviewed in animal studies or clinical trials for endometriosis patients nowadays. However, the therapeutic effects of luteolin in human endometriosis have not been studied well. Here, we demonstrate that luteolin exerts antiproliferative and apoptotic effects in human VK2/E6E7 and End1/E6E7 and in an animal endometriosis model. Luteolin inhibits cell proliferation through cell cycle arrest and induces apoptosis through DNA fragmentation in VK2/E6E7 and End1/E6E7 cells. Cytosolic calcium levels, ROS production and lipid peroxidation also increased dose-dependently (0, 5, 10 and 20 μM) in the treatment with luteolin. In VK2/E6E7 and End1/E6E7 cells, luteolin decreased ERK1/2, JNK and PI3K/AKT signal proteins while activating P38. In addition, intraperitoneal injection of luteolin in the endometriosis mouse model reduced lesion size compared to vehicle-injected mice. Ccne1, Cdk2 and Cdk4 were significantly down-regulated in the autoimplanted endometriosis lesions of mice intraperitoneally injected with luteolin. Knockdown of CCNE1 mRNA in VK2/E6E7 and End1/E6E7 cells decreased cell viability through inhibition of G0/G1 phase progression and increased apoptosis. Together, our results imply that luteolin suppresses endometriosis development by regulation of the PI3K/AKT and MAPK signal proteins as well as the expression of CCNE1 in vitro and in vivo.

Casticin-Induced Inhibition of Cell Growth and Survival Are Mediated through the Dual Modulation of Akt/mTOR Signaling Cascade

The Akt/mTOR signaling cascade is a critical pathway involved in various physiological and pathological conditions, including regulation of cell proliferation, survival, invasion, and angiogenesis. In the present study, we investigated the anti-neoplastic effects of casticin (CTC), identified from the plant Vitex rotundifolia L., alone and/or in combination with BEZ-235, a dual Akt/mTOR inhibitor in human tumor cells. We found that CTC exerted a significant dose-dependent cytotoxicity and reduced cell proliferation in a variety of human tumor cells. Also, CTC effectively blocked the phosphorylation levels of Akt (Ser473) and mTOR (Ser2448) proteins as well as induced substantial apoptosis. Additionally treatment with CTC and BEZ-235 in conjunction resulted in a greater apoptotic effect than caused by either agent alone thus implicating the anti-neoplastic effects of this novel combination. Overall, the findings suggest that CTC can interfere with Akt/mTOR signaling cascade involved in tumorigenesis and can be used together with pharmacological agents targeting Akt/mTOR pathway.