Discovery of chrysoeriol, a PI3K-AKT-mTOR pathway inhibitor with potent antitumor activity against human multiple myeloma cells in vitro

Research Progress on Anti-Inflammatory Mechanism of Inula cappa

The incidence of various inflammatory diseases has remained high. Inula cappa is a kind of Chinese herbal medicine with a wide range of pharmacological uses and application value. It has anti-inflammatory, antibacterial, antioxidant, hepatoprotective and other pharmacological activities. The monomeric compounds that have been confirmed to have anti-inflammatory effects are luteolin, chrysoerilol, artemetin, chlorogenic acid, neochlorogenic acid, cryptchlorogenic acid, isochlorogenic acid A, isochlorogenic acid B, isochlorogenic acid C and 1,3-O-dicaffeoylquinic acid. This article introduces the relationship between Inula cappa and inflammation, the anti-inflammatory components of I. cappa, the modulation of each component on the inflammatory transduction signal pathway, and the TLR2/MyD88/NF-KB anti-inflammatory signaling pathway, providing a theoretical basis for anti-inflammatory research on and clinical medication using Inula cappa.

Network Pharmacology and In silico Elucidation of Phytochemicals Extracted from Ajwa Dates (Phoenix dactylifera L.) to Inhibit Akt and PI3K Causing Triple Negative Breast Cancer (TNBC)

BACKGROUND

About 10-15% of all breast cancers comprise triple-negative breast cancer (TNBC), defined as cancer cells that lack ER, PR, and HER2 protein receptors. Due to the absence of these receptors, treating TNBC using conventional chemotherapy is challenging and, therefore, requires the discovery of novel chemotherapeutic agents derived from natural sources.

OBJECTIVE

The current work was intended to study the potential phytochemicals of Ajwa dates (Phoenix dactylifera L.) with the predicted potential targets (namely, Akt and PI3K) to determine possible TNBC inhibitors.

METHODS

We harnessed network pharmacology, molecular docking, drug-likeness studies, Molecular Dynamics (MD) simulation, and binding free energy (MM-GBSA) calculation to get phytochemicals with potential effects against TNBC. Firstly, molecular docking was performed on 125 phytochemicals against the Akt and PI3K proteins utilizing PyRx. Then, the phytochemicals with the highest binding affinity (≤ -8.1 kcal/mol) were examined for in silico drug-likeness and toxicity profiles. Finally, phytochemicals with optimal druglikeness and toxicity profiles were studied by Molecular Dynamics (MD) simulation and binding free energy (MM-GBSA) to identify compounds that can form stable complexes.

RESULTS

The results of the network pharmacology revealed that the Akt and PI3K proteins are potential targets of TNBC for the phytochemicals of Phoenix dactylifera L. used in this study. The outcomes of molecular docking displayed that among 125 phytochemicals, 42 of them (with a binding affinity ≤ -8.1 kcal/mol) have potentially inhibiting effects on both proteins PI3K and Akt expressed in TNBC. Then, the results of in silico drug-likeness identified seven phytochemicals with optimal pharmacokinetic profiles. Furthermore, toxicity studies showed that three phytochemicals (namely, Chrysoeriol, Daidzein, and Glycitein) did not cause any toxicities. Finally, the Molecular Dynamics (MD) simulation studies and binding free energy (MM-GBSA) verified that Daidzein stayed within the binding cavities of both proteins (Akt and PI3K) by establishing a stable protein-ligand complex during simulation.

CONCLUSION

Taken together, the current work emphasizes the potential effects of Daidzein from Phoenix dactylifera L. against TNBC, and it can be further studied to establish it as a standard chemotherapy for TNBC.

The mechanism of flavonoids from Cyclocarya paliurus on inhibiting liver cancer based on in vitro experiments and network pharmacology

Introduction: Cyclocarya paliurus (Batal.) Iljinsk., a subtropical tree belonging to the family Juglandaceae, is rich in polysaccharides, flavonoids, and terpenoids. It has important pharmacological effects such as lowering blood lipids, blood sugar, and blood pressure. However, little has been discerned regarding anti tumor effects and their potential mechanisms. Method: In vitro cell culture experiments were used to test the effect of C. paliurus total flavonoids (CTFs) extract on apoptosis mechanisms in HepG2 cells. Network pharmacology was applied to further explore the effects of CTFs on liver cancer as well as the mechanisms through which these effects might be achieved. Both 3 hydroxyflavone and luteolin were randomly selected to verify the effect on inducing apoptosis and inhibiting the proliferation of HepG2 cells. Results and Discussion: Network pharmacological analysis was applied to these 62 compounds and their targets, and 13 flavonoids were further screened for their potential anti liver cancer activity. These 13 flavonoids included: tangeretin, baicalein, 7,3'-dihydroxyflavone, velutin, 3-hydroxyflavone, chrysin, kumatakenin, tricin, luteolin, chrysoeriol, apigenin, pinocembrin, and butin. Together, these flavonoids were predicted to interact with AKT1, MAPK3, PIK3CA, EGFR, MAP2K1, SRC, IGF1R, IKBKB, MET, and MAPK14. It was predicted that the inhibitory effect on hepatocellular carcinoma would be accomplished by regulation of core proteins relating to such KEGG pathways as cancer, PI3K-Akt, proteoglycans in cancer, microRNAs in cancer, and endocrine resistance via core target proteins. Both 3-hydroxyflavone and luteolin were demonstrated to induce apoptosis and inhibit the proliferation of HepG2 cells. Our study provides scientific evidence supporting the use of CTFs for the treatment of liver cancer.

Inhibition of STAT3 signaling contributes to the anti-melanoma effects of chrysoeriol

BACKGROUND

Melanoma is an aggressive malignancy with a high mortality rate. Signal transducer and activator of transcription 3 (STAT3), an oncoprotein, is considered as an effective target for treating melanoma. Chrysoeriol is a flavonoid compound, and possesses anti-tumor activity in lung cancer, breast cancer and multiple myeloma; while whether it has anti-melanoma effects is still not known. Chrysoeriol has been shown to restrain STAT3 signaling in an inflammation mouse model.

PURPOSE

In this study, the anti-melanoma effects of chrysoeriol and the involvement of STAT3 signaling in these effects were investigated.

STUDY DESIGN AND METHODS

CCK8 assays, 5-ethynyl-2'-deoxyuridine (EdU) staining, Annexin V-FITC/PI staining, Western blot analyses of cleaved caspase-9 and wound healing assays were used to study the anti-melanoma effects of chrysoeriol in cell models. A B16F10 melanoma bearing mouse model was used to evaluate the in vivo anti-melanoma effects of chrysoeriol. Indicators of cell proliferation, cell apoptosis and angiogeneis in melanoma tissues were detected by immunohistochemistry (IHC) staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining. Immune cells in melanoma tissues were analyzed by flow cytometry. STAT3-overactivated cell models were used to investigate the involvement of STAT3 signaling in the anti-melanoma effects of chrysoeriol. Molecular dynamics (MD) simulations and surface plasmon resonance (SPR) assays were conducted to determine whether chrysoeriol binds to Src, an upstream kinase of STAT3.

RESULTS

The results of cell experiments showed that chrysoeriol dose-dependently inhibited viability, proliferation and migration of, and induced apoptosis in, A375 and B16F10 melanoma cells. Chrysoeriol inhibited the phosphorylation of STAT3, and downregulated the expression of STAT3-target genes involved in melanoma growth and metastasis. Mouse studies showed that chrysoeriol restrained melanoma growth and tumor-related angiogenesis, and altered compositions of immune cells in melanoma microenvironment. Chrysoeriol also inhibited STAT3 signaling in B16F10 allografts. Chrysoeriol's viability-inhibiting effects were attenuated by over-activating STAT3 in A375 cells. Furthermore, chrysoeriol bound to the protein kinase domain of Src, and suppressed Src phosphorylation in melanoma cells and tissues.

CONCLUSION

This study, for the first time, demonstrates that chrysoeriol has anti-melanoma effects, and these effects are partially due to inhibiting STAT3 signaling. Our findings indicate that chrysoeriol has the potential to be developed into an anti-melanoma agent.

Suppression of PI3K/Akt/mTOR pathway in chrysoeriol-induced apoptosis of rat C6 glioma cells

Chrysoeriol, a dietary methoxyflavonoid which is found in tropical medicinal plants, has been shown to have antioxidant, anti-inflammatory, and antineoplastic properties. The present study aimed to investigate the effects of chrysoeriol and its related mechanisms in rat C6 glioma cells. Cell viability in rat C6 glioma cells were measured by MTT assay. The protein expression levels of cleaved caspase-3, caspase-3, pro-apoptotic (Bax), anti-apoptotic protein (Bcl-2), and Annexin V were detected by Western blot analysis and immunocytochemical staining. Results showed that chrysoeriol significantly decreased cell viability and induced apoptosis in rat C6 glioma cells. Chrysoeriol significantly increased the levels of Bax/Bcl-2 ratio and cleaved caspase-3/caspase-3 ratio. Moreover, treatment with chrysoeriol significantly reduced the phosphorylation of PI3K, Akt, and mTOR expression in ratios. These results suggest that chrysoeriol promote apoptosis in rat C6 glioma cells via suppression of the PI3K/Akt/mTOR signaling pathway, thereby demonstrating the potential antineoplastic effects of chrysoeriol on glioma cells.

Isolation, separation, identification, and quantification of bioactive methylated flavone regioisomers by UHPLC-MS/MS

Methylated flavones, commonly found in many plants of the Brassicaceae family, have potent antioxidant and anticancer activity with diverse therapeutic potential. However, the specific regioisomers of methylated flavones can have significantly different biochemical and potentially therapeutic properties as shown by various bioassays but analytically differentiating these compounds has been technically challenging and rarely reported. In this study, we demonstrate differentiation and identification of selected bioactive methylated flavone regioisomers, namely 5,7,3'-trihydroxy-4'-methoxyflavone, and 5,7,4'-trihydroxy-3'-methoxyflavone extracted from Coronopus didymus, a member of the Brassicaceae family, using ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC-ESI-QTOF-MS/MS). Characteristic MS/MS product ions produced from neutral loss of carbon monoxide, and a methyl radical from the [M-H]- ion, exhibited differential relative abundances attributed to different structural stabilities under the same activation and collision-induced dissociation conditions. MS/MS also provided structural information which was sufficient to differentiate the methylated regioisomers and determine the position of the methyl group based on interpretation of their respective fragmentation patterns. Quantification showed 5,7,4'-trihydroxy-3'-methoxyflavone was at least 1.60 mg per 10 g plant material in C. didymus extracts. This study demonstrates a straightforward and novel approach to rapidly differentiate, identify and quantify regio-isomeric methylated flavone natural products using reversed-phase UPLC-MS/MS.

Bioactive Compounds from Herbal Medicine Targeting Multiple Myeloma

Multiple myeloma (MM) is one of the most widespread hematological cancers. It is characterized by a clonal proliferation of malignant plasma cells in the bone marrow and by the overproduction of monoclonal proteins. In recent years, the survival rate of patients with multiple myeloma has increased significantly due to the use of transplanted stem cells and of the new therapeutic agents that have significantly increased the survival rate, but it still cannot be completely cured and therefore the development of new therapeutic products is needed. Moreover, many patients have various side effects and face the development of drug resistance to current therapies. The purpose of this review is to highlight the bioactive active compounds (flavonoids) and herbal extracts which target dysregulated signaling pathway in MM, assessed by in vitro and in vivo experiments or clinical studies, in order to explore their healing potential targeting multiple myeloma. Mechanistically, they demonstrated the ability to promote cell cycle blockage and apoptosis or autophagy in cancer cells, as well as inhibition of proliferation/migration/tumor progression, inhibition of angiogenesis in the tumor vascular network. Current research provides valuable new information about the ability of flavonoids to enhance the apoptotic effects of antineoplastic drugs, thus providing viable therapeutic options based on combining conventional and non-conventional therapies in MM therapeutic protocols.

Chrysoeriol ameliorates COX-2 expression through NF-κB, AP-1 and MAPK regulation via the TLR4/MyD88 signaling pathway in LPS-stimulated murine macrophages

Chrysoeriol is a flavonoid that has diverse biological properties, including antioxidation, anti-inflammation, chemoprevention and immunomodulation. Despite its reported anti-inflammatory activity, the exact underlying molecular mechanism has not yet been elucidated. In the current study, the anti-inflammatory mechanism of chrysoeriol involving lipopolysaccharide (LPS)-induced cyclooxygenase-2 (COX-2) and its upstream signaling molecules was investigated in RAW 264.7 cells. The mechanism was evaluated via ELISA and western blotting assays. Chrysoeriol significantly inhibited LPS-induced prostaglandin E₂ (PGE₂) production and COX-2 expression without cytotoxicity. Activated transcription factors that further induced the inflammation response, including nuclear factor (NF)-κB and activator protein-1 (AP-1), were significantly attenuated by chrysoeriol treatment. Furthermore, LPS-induced phosphorylation levels of phosphoinositide-3-kinase (PI3K)/Akt and mitogen-activated protein kinase (MAPK) were abolished by chrysoeriol treatment, which was confirmed by selective inhibitors. Additionally, chrysoeriol significantly inhibited the LPS-induced activation of adaptor molecules in RAW 264.7 cells, including toll-like receptor 4 (TLR4) and myeloid differentiation primary response 88. Therefore, the results suggested that chrysoeriol ameliorates TLR4-mediated inflammatory responses by inhibiting NF-κB and AP-1 activation as well as suppressing PI3K/Akt and MAPK phosphorylation in LPS-stimulated RAW 264.7 cells.

Role of flavonoids against adriamycin toxicity

Doxorubicin (DOX), or adriamycin, is an anthracycline antineoplastic drug widely used in the chemotherapy of a large variety of cancers due to its potency and action spectrum. However, its use is limited by the toxicity on healthy cells and its acute and chronic side effects. One of the developed strategies to attenuate DOX toxicity is the combined therapy with bioactive compounds such as flavonoids. This review embraces the role of flavonoids on DOX treatment side effects. Protective properties of some flavonoidss against DOX toxicity have been investigated and observed mainly in heart but also in liver, kidney, brain, testis or bone marrow. Protective mechanisms involve reduction of oxidative stress by decrease of ROS levels and/or increase antioxidant defenses and interferences with autophagy, apoptosis and inflammation. Studies in cancer cells have reported that the anticancer activity of DOX was not compromised by the flavonoids. Moreover, some of them increased DOX efficiency as anti-cancer drug even in multidrug resistant cells.

Integrated transcriptomic and metabolomic data reveal the flavonoid biosynthesis metabolic pathway in Perilla frutescens (L.) leaves

Perilla frutescens (L.) is an important medicinal and edible plant in China with nutritional and medical uses. The extract from leaves of Perilla frutescens contains flavonoids and volatile oils, which are mainly used in traditional Chinese medicine. In this study, we analyzed the transcriptomic and metabolomic data of the leaves of two Perilla frutescens varieties: JIZI 1 and JIZI 2. A total of 9277 differentially expressed genes and 223 flavonoid metabolites were identified in these varieties. Chrysoeriol, apigenin, malvidin, cyanidin, kaempferol, and their derivatives were abundant in the leaves of Perilla frutescens, which were more than 70% of total flavonoid contents. A total of 77 unigenes encoding 15 enzymes were identified as candidate genes involved in flavonoid biosynthesis in the leaves of Perilla frutescens. High expression of the CHS gene enhances the accumulation of flavonoids in the leaves of Perilla frutescens. Our results provide valuable information on the flavonoid metabolites and candidate genes involved in the flavonoid biosynthesis pathways in the leaves of Perilla frutescens.

Citrus Flavones: An Update on Sources, Biological Functions, and Health Promoting Properties

Citrus spp. are among the most widespread plants cultivated worldwide and every year millions of tons of fruit, juices, or processed compounds are produced and consumed, representing one of the main sources of nutrients in human diet. Among these, the flavonoids play a key role in providing a wide range of health beneficial effects. Apigenin, diosmetin, luteolin, acacetin, chrysoeriol, and their respective glycosides, that occur in concentrations up to 60 mg/L, are the most common flavones found in Citrus fruits and juices. The unique characteristics of their basic skeleton and the nature and position of the substituents have attracted and stimulated vigorous investigations as a consequence of an enormous biological potential, that manifests itself as (among other properties) antioxidant, anti-inflammatory, antiviral, antimicrobial, and anticancer activities. This review analyzes the biochemical, pharmacological, and biological properties of Citrus flavones, emphasizing their occurrence in Citrus spp. fruits and juices, on their bioavailability, and their ability to modulate signal cascades and key metabolic enzymes both in vitro and in vivo. Electronic databases including PubMed, Scopus, Web of Science, and SciFinder were used to investigate recent published articles on Citrus spp. in terms of components and bioactivity potentials.

Plumbagin inhibits cell proliferation and promotes apoptosis in multiple myeloma cells through inhibition of the PI3K/Akt-mTOR pathway

Plumbagin is the primary component of the traditional Chinese medicine Baihua Dan, and possesses anti-infection and anticancer effects with the ability to enhance the sensitivity of tumor cells to radiation therapy. The present study aimed to investigate the potential anticancer effect and mechanism of plumbagin on multiple myeloma (MM) cells. Human MM OPM1 cells were treated with plumbagin, and its impact on cell viability, cytotoxicity, apoptosis and caspase-3 activity was examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, lactate dehydrogenase leakage, flow cytometry and colorimetric assays. In addition, the protein expression levels of phosphoinositide 3-kinase, phosphorylated (p)-Akt and p-mammalian target of rapamycin (mTOR) in OPM1 cells were analyzed by western blotting. The results demonstrated that plumbagin treatment inhibited cell viability, increased cell cytotoxicity, activated cell apoptosis and promoted caspase-3 activity in the OPM1 cells. Furthermore, pretreatment of plumbagin significantly suppressed PI3K, p-Akt and p-mTOR protein expression levels in the OPM1 cells. In conclusion, the present study indicates that plumbagin inhibits cell proliferation and promotes apoptosis in MM cells through inhibition of PI3K/Akt-mTOR expression.

The Protective Role of Phenolic Compounds Against Doxorubicin-induced Cardiotoxicity: A Comprehensive Review

Although doxorubicin (DOX) is among the most widely used anticancer agents, its clinical application is hampered owing to its cardiotoxicity. Adjuvant therapy with an antioxidant has been suggested as a promising strategy to reduce DOX-induced adverse effects. In this context, many phenolic compounds have been reported to protect against DOX-induced cardiotoxicity. The cardioprotective effects of phenolic compounds are exerted via multiple mechanisms including inhibition of reactive oxygen species generation, apoptosis, NF-κB, p53, mitochondrial dysfunction, and DNA damage. In this review, we present a summary of the in vitro, in vivo, and clinical findings on the protective mechanisms of phenolic compounds against DOX-induced cardiotoxicity.

The detection of risk pathways, regulated by miRNAs, via the integration of sample-matched miRNA-mRNA profiles and pathway structure

The use of genome-wide, sample-matched miRNA (miRNAs)-mRNA expression data provides a powerful tool for the investigation of miRNAs and genes involved in diseases. The identification of miRNA-regulated pathways has been crucial for analysis of the role of miRNAs. However, the classical identification method fails to consider the structural information of pathways and the regulation of miRNAs simultaneously. We proposed a method that simultaneously integrated the change in gene expression and structural information in order to identify pathways. Our method used fold changes in miRNAs and gene products, along with the quantification of the regulatory effect on target genes, to measure the change in gene expression. Topological characteristics were investigated to measure the influence of gene products on entire pathways. Through the analysis of multiple myeloma and prostate cancer expression data, our method was proven to be effective and reliable in identifying disease risk pathways that are regulated by miRNAs. Further analysis showed that the structure of a pathway plays a crucial role in the recognition of the pathway as a factor in disease risk.

Isorhamnetin suppresses colon cancer cell growth through the PI3K‑Akt‑mTOR pathway

Isorhamnetin, a flavonoid isolated from the fruits of herbal medicinal plants, such as Hippophae rhamnoides L., exerts anticancer effects similar to other flavonoids. However, the effect of isorhamnetin on colorectal cancer (CRC) and the underlying molecular mechanism are unclear. This study aimed to determine the effect of isorhamnetin on the proliferation of cells from the human CRC cell lines, HT‑29, HCT116 and SW480. It was demonstrated that isorhamnetin suppressed the proliferation of cells from all three cell lines, induced cell cycle arrest at the G2/M phase and suppressed cell proliferation by inhibiting the PI3K‑Akt‑mTOR pathway. Isorhamnetin also reduced the phosphorylation levels of Akt (ser473), phosph‑p70S6 kinase and phosph‑4E‑BP1 (t37/46) protein, and enhanced the expression of Cyclin B1 protein. Therefore, this compound was revealed to be a selective PI3K‑Akt‑mTOR pathway inhibitor, and may be a potent anticancer agent for the treatment of CRC, as it restrains the proliferation of CRC cells.