Scutellarin-induced apoptosis in HepG2 hepatocellular carcinoma cells via a STAT3 pathway

Scutellarin combined with lidocaine exerts antineoplastic effect in human glioma associated with repression of epidermal growth factor receptor signaling

PURPOSE

Glioma is the most common primary intracranial tumors. Although great achievements have been made in the treatment, the efficacy is still unsatisfactory, which imposes a hefty burden on patients and society. Therefore, the exploration of new and effective anti-glioma drugs is urgent.

METHODS

Human glioma cell lines U251 and LN229 were included in the study. Cell proliferation was detected by cell counting kit-8 (CCK8), plate clone formation assay, EdU incorporation assay and xCELLigence real-time cell analyzer. Cell apoptosis was evaluated by TUNEL assay and flow cytometry. Then, transwell assay was used for assessing the migration. Moreover, tumor xenograft model was established to examine the effect of scutellarin (SCU) and lidocaine on the growth of glioma in vivo. Lastly, western blot was performed to detect the protein level of epidermal growth factor receptor (EGFR).

RESULTS

In present study, we found that SCU and lidocaine suppressed the proliferation and migration, and induced the apoptosis of human glioma cell lines, including U251 and LN229 cells, in a dose-dependent manner in vitro. Moreover, the combination of SCU and lidocaine further restrained the proliferation and migration ability of U251 and LN229 cells, while induced their apoptosis in vitro. Additionally, SCU and lidocaine also inhibited the growth of glioma in vivo, and the effect of the combination was better. Above all, the toxicity of SCU and its combination with lidocaine was low to normal astrocytes and neurons. Mechanistically, the effect of SCU and its combination with lidocaine on glioma cells was partially associated with the repression of EGFR signaling.

CONCLUSIONS

Scutellarin and lidocaine exerted a synergistic effect on suppressing the proliferation and migration and inducing the apoptosis of glioma cells, which was partly associated with the repression of EGFR signaling.

Exploration of novel isoxazole-fused quinone derivatives as anti-colorectal cancer agents through inhibiting STAT3 and elevating ROS level

Colorectal cancer (CRC) is trending to be a major health problem throughout the world. Therapeutics with dual modes of action have shown latent capacity to create ideal anti-tumor activity. Signal transducer and activator of transcription 3 (STAT3) has been proved to be a potential target for the development of anti-colon cancer drug. In addition, modulation of tumor redox homeostasis through deploying exogenous reactive oxygen species (ROS)-enhancing agents has been widely applied as anti-tumor strategy. Thus, simultaneously targeting STAT3 and modulation ROS balance would offer a fresh avenue to combat CRC. In this work, we designed and synthesized a novel series of isoxazole-fused quinones, which were evaluated for their preliminary anti-proliferative activity against HCT116 cells. Among these quinones, compound 41 exerted excellent in vitro anti-tumor effect against HCT116 cell line with an IC50 value of 10.18 ± 0.4 nM. Compound 41 was proved to bind to STAT3 by using Bio-Layer Interferometry (BLI) assay, and can significantly inhibit phosphorylation of STAT3. It also elevated ROS of HCT116 cells by acting as a substrate of NQO1. Mitochondrial dysfunction, apoptosis, and cell cycle arrest, which was caused by compound 41, might be partially due to the inhibition of STAT3 phosphorylation and ROS production induced by 41. Moreover, it exhibited ideal anti-tumor activity in human colorectal cancer xenograft model and good safety profiles in vivo. Overall, this study provided a novel quinone derivative 41 with excellent anti-tumor activity by inhibiting STAT3 and elevating ROS level, and gave insights into designing novel anti-tumor therapeutics by simultaneously modulation of STAT3 and ROS.

Targeting dysregulated lipid metabolism in the tumor microenvironment

The reprogramming of lipid metabolism and its association with oncogenic signaling pathways within the tumor microenvironment (TME) have emerged as significant hallmarks of cancer. Lipid metabolism is defined as a complex set of molecular processes including lipid uptake, synthesis, transport, and degradation. The dysregulation of lipid metabolism is affected by enzymes and signaling molecules directly or indirectly involved in the lipid metabolic process. Regulation of lipid metabolizing enzymes has been shown to modulate cancer development and to avoid resistance to anticancer drugs in tumors and the TME. Because of this, understanding the metabolic reprogramming associated with oncogenic progression is important to develop strategies for cancer treatment. Recent advances provide insight into fundamental mechanisms and the connections between altered lipid metabolism and tumorigenesis. In this review, we explore alterations to lipid metabolism and the pivotal factors driving lipid metabolic reprogramming, which exacerbate cancer progression. We also shed light on the latest insights and current therapeutic approaches based on small molecular inhibitors and phytochemicals targeting lipid metabolism for cancer treatment. Further investigations are worthwhile to fully understand the underlying mechanisms and the correlation between altered lipid metabolism and carcinogenesis.

Network pharmacology-based investigation and experimental validation of the mechanism of scutellarin in the treatment of acute myeloid leukemia

Background: It has been demonstrated that scutellarin, a natural flavone compound from Scutellaria lateriflora and Scutellaria barbata, exerts selective cytotoxicity against a range of cancer cells. However, the underlining mechanism of scutellarin on acute myeloid leukemia (AML) remains elusive.

Methods: In this study, the combination of network pharmacology and experimental verification was performed to identify the pharmacological mechanisms of scutellarin for AML therapy. The public databases, such as PharmMapper, UniProt, OMIM, GeneCards, DrugBank and PharmGkb database, were used to sceen the potential targets of scutellarin and AML. The protein-protein interaction (PPI), gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were conducted to uncover the mechanism of scutellarin in the treatment of AML. Finally, the network pharmacological results were further confirmed by in vitro and in vivo experiments.

Results: First and foremost, we totally obtained 289 target genes for scutellarin and 10998 disease targets for AML. 253 overlapping genes were preliminarily considered the potential targets of scutellarin for AML treatment. The results of PPI network analysis, GO analysis and KEGG pathway enrichment demonstrated that the anti-AML effect of scutellarin may focused on MAPK signaling pathway. Furthermore, the cytologic tests suggested that scutellarin can inhibit AML cells proliferation through the mediation of JNK/Caspase-3 pathway. Meanwhile, pretreatment with the JNK inhibitor SP600125 rescued scutellarin-induced apoptosis. Similarly, scutellarin obviously suppressed subcutaneous xenograft growth in nude mice via regulating the JNK/Caspase-3 signaling pathway.

Conclusion: In this study, we integrated network pharmacology-based prediction and experimental validation and revealed the importance of the JNK pathway in scutellarin-mediated AML treatment.

Novel Insights of Herbal Remedy into NSCLC Suppression through Inducing Diverse Cell Death Pathways via Affecting Multiple Mediators

Artemisia species previously have been reported to have antimicrobial, antioxidant, antiulcer, and anticancer properties. In this study, we investigated the prospective antitumor effects of Artemisia santolinifolia ethanol extract (ASE) against two non-small cell lung cancer (NSCLC) cell lines and their molecular mechanisms of action. Morphological observations and flow cytometric analyses showed that ASE induced cell death in A549 and H23 cells but with different action features. Further studies by Western blotting showed that ASE induced caspase-3 cleavage in H23 cells, suggesting caspase-dependent apoptosis was predominantly involved in H23 cell death. Contrarily, ASE treatment selectively altered the glutathione peroxidase (GPX4) protein expression, reactive oxygen species (ROS) generation, and lipid peroxidation in A549 cells, all of which are linked to ferroptosis. Using a ferroptosis inhibitor (desferrioxamine (DFO)), further study showed that DFO could significantly rescue ASE-induced cell death. All these results implied that ASE induced ferroptosis predominately in A549 cells. Several studies have demonstrated that the nuclear factor erythroid 2–related factor 2 (NRF2) can be dual-selectively targeted depending on the cell line. Subsequently, it can exert opposing effects until either being activated or suppressed. This was consistent with our data, which might explain inconsistent observations of the cell death type in this study. In addition, after ASE treatment, signal transduction and activator of transcription 3 (STAT3) were inhibited in both cell lines. Consequently, downstream prosurvival proteins, including heat shock protein 70 (HSP70) and survivin, which play pivotal roles in the STAT3 pathway, decreased after ASE administration. Our findings revealed that ASE inhibited NSCLC cell proliferation by simultaneously downregulating prosurvival protein expressions and activating multiple cell death pathways.

Scutellarin ameliorates neonatal hypoxic-ischemic encephalopathy associated with GAP43-dependent signaling pathway

Background

Neonatal hypoxic-ischemic encephalopathy (HIE) refers to the perinatal asphyxia caused by the cerebral hypoxic-ischemic injury. The current study was aimed at investigating the therapeutic efficacy of Scutellarin (Scu) administration on neurological impairments induced by hypoxic-ischemic injury and exploring the underlying mechanisms.

Methods

Primary cortical neurons were cultured and subjected to oxygen–glucose deprivation (OGD), and then treated with Scu administration. The growth status of neurons was observed by immunofluorescence staining of TUJ1 and TUNEL. Besides, the mRNA level of growth-associated protein 43 (GAP43) in OGD neurons with Scu treatment was detected by quantitative real-time polymerase chain reaction (qRT-PCR). To further verify the role of GAP43 in Scu treatment, GAP43 siRNA and knockout were applied in vitro and in vivo. Moreover, behavioral evaluations were performed to elucidate the function of GAP43 in the Scu-ameliorated long-term neurological impairments caused by HI insult. The underlying biological mechanism of Scu treatment was further elucidated via network pharmacological analysis. Finally, the interactive genes with GAP43 were identified by Gene MANIA and further validated by qRT-PCR.

Results

Our data demonstrated that Scu treatment increased the number of neurons and axon growth, and suppressed cell apoptosis in vitro. And the expression of GAP43 was downregulated after OGD, but reversed by Scu administration. Besides, GAP43 silencing aggravated the Scu-ameliorated neuronal death and axonal damage. Meanwhile, GAP43 knockout enlarged brain infarct area and deteriorated the cognitive and motor dysfunctions of HI rats. Further, network pharmacological analysis revealed the drug targets of Scu participated in such biological processes as neuronal death and regulation of neuronal death, and apoptosis-related pathways. GAP43 exhibited close relationship with PTN, JAK2 and STAT3, and GAP43 silencing upregulated the levels of PTN, JAK2 and STAT3.

Conclusions

Collectively, our findings revealed Scu treatment attenuated long-term neurological impairments after HI by suppressing neuronal death and enhancing neurite elongation through GAP43-dependent pathway. The crucial role of Scutellarin in neuroprotection provided a novel possible therapeutic agent for the treatment of neonatal HIE.

Graphic abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13020-021-00517-z.

Combined Scutellarin and C18H17NO6 Imperils the Survival of Glioma: Partly Associated With the Repression of PSEN1/PI3K-AKT Signaling Axis

Glioma, the most common intracranial tumor, harbors great harm. Since the treatment for it has reached the bottleneck stage, the development of new drugs becomes a trend. Therefore, we focus on the effect of scutellarin (SCU) and its combination with C₁₈H₁₇NO₆ (abbreviated as combination) on glioma and its possible mechanism in this study. Firstly, SCU and C₁₈H₁₇NO₆ both suppressed the proliferation of U251 and LN229 cells in a dose-dependent manner, and C₁₈H₁₇NO₆ augmented the inhibition effect of SCU on U251 and LN229 cells in vitro. Moreover, there was an interactive effect between them. Secondly, SCU and C₁₈H₁₇NO₆ decreased U251 cells in G2 phase and LN229 cells in G2 and S phases but increased U251 cells in S phase, respectively. Meanwhile, the combination could further reduce U251 cells in G2 phase and LN229 cells in G2 and S phases. Thirdly, SCU and C₁₈H₁₇NO₆ both induced the apoptosis of U251 and LN229. The combination further increased the apoptosis rate of both cells compared with the two drugs alone. Furthermore, SCU and C₁₈H₁₇NO₆ both inhibited the lateral and vertical migration of both cells, which was further repressed by the combination. More importantly, the effect of SCU and the combination was better than positive control-temozolomide, and the toxicity was low. Additionally, SCU and C₁₈H₁₇NO₆ could suppress the growth of glioma in vivo, and the effect of the combination was better. Finally, SCU and the combination upregulated the presenilin 1 (PSEN1) level but inactivated the phosphatidylinositol 3−kinase (PI3K)-protein kinase B (AKT) signaling in vitro and in vivo. Accordingly, we concluded that scutellarin and its combination with C₁₈H₁₇NO₆ suppressed the proliferation/growth and migration and induced the apoptosis of glioma, in which the mechanism might be associated with the repression of PSEN1/PI3K-AKT signaling axis.

Advances in Chemical Constituents, Clinical Applications, Pharmacology, Pharmacokinetics and Toxicology of Erigeron breviscapus

Dengzhanxixin (DZXX), the dried whole plant of Erigeron breviscapus (Vaniot) Hand.-Mazz., belonging to Compositae and first published in Materia Medica of South Yunnan by Lan Mao in the Ming Dynasty (1368 AD–1644 AD), is included in Medicinal Materials and Decoction Pieces of the 2020 edition of the Pharmacopeia of the People’s Republic of China. Its main chemical components are flavonoids that mainly include flavonoid, flavonols, dihydroflavones, flavonol glycosides, flavonoid glycosides, coffee acyl compounds, and other substances, such as volatile oil compounds, coumarins, aromatic acids, pentacyclic terpenoids, phytosterols, and xanthones. Among them, scutellarin and 1,5-dicoffeoylquininic acid are the main active components of DZXX. DZXX has pharmacological effects, such as improving cerebral and cerebrovascular ischemia, increasing blood flow, inhibiting platelet aggregation, promoting antithrombotic formation, improving microcirculation, reducing blood viscosity, protecting optic nerves, exhibiting anti-inflammatory properties, scavenging free radicals, and eliciting antioxidant activities. It is widely used in the treatment of cardiovascular and cerebrovascular ischemic diseases, kidney diseases, liver diseases, diabetic complications, and glaucoma. Pharmacokinetic studies have shown that the active components of DZXX have a low bioavailability and a high elimination rate in vivo. Nevertheless, its utilization can be improved through liposome preparation and combination with other drugs. Acute and subacute toxicity studies have shown that DZXX is a safe medicinal material widely used in clinical settings. However, its target and drug action mechanism are unclear because of the complexity of its composition. In this paper, the clinical application and pharmacological toxicology of DZXX are reviewed to provide a reference for further studying its active components and action mechanism.

Potential Treatment of Breast and Lung Cancer Using Dicoma anomala, an African Medicinal Plant

Globally, cancer has been identified as one of the leading causes of death in public health. Its etiology is based on consistent exposure to carcinogenic. Plant-derived anticancer compounds are known to be less toxic to the normal cells and are classified into acetylenic compounds, phenolics, terpenes, and phytosterols. Dicoma anomala is a perennial herb belonging to the family Asteraceae and is widely distributed in Sub-Saharan Africa and used in the treatment of cancer, malaria, fever, diabetes, ulcers, cold, and cough. This review aimed at highlighting the benefits of D. anomala in various therapeutic applications with special reference to the treatment of cancers and the mechanisms through which the plant-derived agents induce cell death.

Anti-colorectal cancer effects of scutellarin revealed by genomic and proteomic analysis

Background

Colorectal cancer, one of the most common digestive tumors with high mortality and morbidity worldwide, currently lacks effective therapies available to improve the prognosis. This study was aimed to investigate the potency of Scutellarin against colorectal cancers, and explore the related mechanism via genomic and proteomic analysis.

Methods

Cell counting kit-8 assay was employed to detect the viability of HCT-116 and RKO cell lines treated with Scutellarin. The apoptosis of HCT-116 and RKO cells after Scutellarin administration was determined by TUNEL staining and Caspase 3/7 activity. Cell cycle was detected by flow cytometry analysis. The wound healing and transwell invasion test detected the role of Scutellarin in migration and invasion of HCT-116 and RKO cells. Meanwhile, the energy metabolism and growth of tumor tissues in vivo at day 28 were observed by PET-CT after Scutellarin administration with 50 mg/kg, 100 mg/kg and 300 mg/kg into 4-week-old nude mice. Blood routine and liver functions were also detected to evaluate the side effect of Scutellarin. Furthermore, the disease and function classifications which the differentially expressed genes and proteins involved after Scutellarin treatment were determined by genomic and proteomic analysis respectively.

Results

The Scutellarin inhibited the migration and increased apoptosis of HCT-116 and RKO cell lines. Besides, Scutellarin treatment substantially decreased the growth and volume of colorectal tumors in nude mice without side effects on the blood routine and liver function. The differentially expressed genes in RKO cells after Scutellarin administration were mainly enriched in cell death and survival, organismal injury and abnormalities, and cancer. In addition, forty-seven upregulated and twenty-nine downregulated proteins were identified. Functional clustering analysis exhibited enriched biological processes, cellular components, molecular functions and related pathways of these proteins in cellular metabolic. Then protein–protein interactions analysis showed the regulatory relationship among these differentially expressed proteins.

Conclusions

Taken together, the present findings revealed that Scutellarin exerted significant antitumor effect with no side effects in the blood and liver by regulating various important molecules in tumor proliferation, apoptosis and metastasis.

Scutellarin inhibits hypoxia-induced epithelial-mesenchymal transition in bladder cancer cells

Scutellarin, an active component of flavonoid, displays a variety of physiological actions and has been applied for the treatment of diverse diseases including hypertension and cerebral infarction as well as cerebral thrombosis. In recent time, Scutellarin has been demonstrated to possess the anticancer activity. But the biological significance of Scutellarin in bladder cancer (BC) remains to be elucidated. In the current study, we explored the specific effect of Scutellarin on BC progression. We found that Scutellarin inhibited hypoxia-induced BC cell migration and invasion in vitro as well as suppressed hypoxia-induced BC metastasis in vivo. Moreover, Scutellarin significantly reversed hypoxia-promoted epithelial-mesenchymal transition (EMT) in BC cells and the PI3K/Akt and MAPK pathways were implicated in the suppressive effect. Taken together, we suggested the potential value of Scutellarin as a novel anticancer agent for BC treatment.

C18H17NO6 and Its Combination with Scutellarin Suppress the Proliferation and Induce the Apoptosis of Human Glioma Cells via Upregulation of Fas-Associated Factor 1 Expression

Background

Glioma is the most common malignant brain tumor and the patients are prone to poor prognosis. Due to limited treatments, new drug exploration has become a general trend. Therefore, the objective of this study is to investigate the effect of the new drugs C₁₈H₁₇NO₆ and its combination with Scutellarin on glioma cells and the underlying mechanism.

Method

U251 and LN229 cells were administrated with C₁₈H₁₇NO₆ and its combination with Scutellarin. The proliferation ability of glioma cells was determined by cell counting kit-8, plate clone formation assay, and EdU incorporation assay. The cell cycle and apoptosis detection were detected by flow cytometry. Moreover, TUNEL assay was also used for cell apoptosis analysis. Then, the transfer ability of cells was achieved through wound healing assay. Furthermore, polymerase chain reaction (PCR) test and western bolt analysis were used to detect the mRNA expression and protein expression, respectively. Lastly, immunofluorescence was for the purity identification of astrocyte.

Result

The results showed that, with the increasing dose of C₁₈H₁₇NO₆, the cell inhibition rate, the cells in G1 phase, and the apoptosis rate were gradually increased, but the clone number, proliferation rate, and the cells in G2 and S phases were gradually decreased in comparison with control group. However, with the increase of C₁₈H₁₇NO₆, the transferred rate of U251 and LN229 was not significantly augmented, expect that on U251 in C₁₈H₁₇NO₆ 5 μM group. In addition, Scutellarin 200 μM has little effect on proliferation, with the inhibition rate 10-20% and proliferation rate except U251 in Scutellarin 200 μM group similar to that in control group. Moreover, compared to control group, Scutellarin 300 μM increased the U251 cells in G2 and S phases and the apoptosis rate of LN229 but decreased the LN229 cells in G2 and S phases. Besides, in Scutellarin 200 μM group, the transfer ability of LN229 was inhibited, but not in U251. Furthermore, if C₁₈H₁₇NO₆ was combined with Scutellarin 200/300μM, the proliferation and transferred ability were suppressed and the apoptosis was elevated in LN229 cell in comparison with C₁₈H₁₇NO₆ alone. Dramatically, the combined effect on U251 was the exact opposite. Importantly, there was little toxicity on astrocyte under the dose of C₁₈H₁₇NO₆ and Scutellarin in the study. In molecular level, the mRNA and protein expression of Fas-associated factor 1 (FAF1) expression in U251 and LN229 were upregulated by C₁₈H₁₇NO₆ and its combination with Scutellarin, especially the protein expression.

Conclusion

C₁₈H₁₇NO₆ could efficiently suppress cell proliferation and induce cell apoptosis in glioma cells, and its combination with Scutellarin had a promoting effect, in which the underlying mechanism referred to the upregulation of Fas-associated factor 1.

Scutellarin inhibits the metastasis and cisplatin resistance in glioma cells

Background

Scutellarin is a natural flavone compound that possesses anti-tumor and chemosensitization effects in several cancers. However, the effects of scutellarin on metastasis and chemoresistance in glioma have not been illustrated.

Methods

Glioma cells were treated with scutellarin in the presence or absence of LY294002. Cell proliferation was measured using a Cell Proliferation BrdU ELISA kit. Cell migration and invasion were analyzed using transwell assay. The expressions of E-cadherin, N-cadherin, vimentin, p-PI3K, PI3K, p-AKT, AKT, p-mTOR and mTOR were measured using Western blot. Furthermore, cells were incubated in the presence of cisplatin with or without the pretreatment of scutellarin. Cell viability was detected by the MTT assay. Cell apoptosis was measured using a histone/DNA ELISA detection kit. The expressions of ABCB1 and ABCG2 were detected using Western blot.

Results

In the present study, we found that scutellarin inhibited the proliferation, migration, and invasion of glioma cells. Scutellarin induced E-cadherin expression and reduced the expressions of N-cadherin, and vimentin in glioma cells. Our results also revealed that scutellarin enhanced chemosensitivity to cisplatin, as evidenced by the decreased cell viability to cisplatin and induced cell apoptosis. Moreover, scutellarin inhibited the expressions of ATP-binding cassette subfamily B member 1 and ATP-binding cassette sub-family G member 2 in cisplatin-resistant glioma cells. Scutellarin also prevented the activation of phosphatidylinositol 3-kinase/Akt/mammalian target of rapamycin pathway.

Conclusion

The data suggested that scutellarin suppressed metastasis and chemoresistance in glioma cells. Scutellarin might be a new therapeutic approach for the glioma therapy.

Scutellarin protects human retinal pigment epithelial cells against hydrogen peroxide (H2O2)-induced oxidative damage

Background

Proliferative vitreoretinopathy (PVR) is a severe blinding complication of retinal detachment surgery. Increasing evidence demonstrate that PVR is associated with oxidative stress. Scutellarin is a natural flavone compound that has been reported to have anti-oxidative activity. However, the effect of scutellarin on PVR remains unknown. In the current study, we assessed the effect of scutellarin on hydrogen peroxide (H₂O₂)-induced oxidative injury in human retinal pigment epithelium cells (ARPE-19).

Methods

ARPE-19 cells were pretreated with different concentrations of scutellarin for 2 h, and then challenged with H₂O₂ (1 mM) for 24 h. The levels of reactive oxygen species (ROS), malondialdehyde (MDA) and superoxide dismutase (SOD) and glutathione (GSH) activity were measured to assess the level of oxidative stress. Flow cytometry was performed to detect the apoptosis rate of ARPE-19 cells. Expression levels of bcl-2, bax, cleaved-caspase-3, p-JAK2, JAK2, p-STAT3, and STAT3 were measured using western blot.

Results

Our results revealed that scutellarin improved the cell viability of H₂O₂-induced ARPE-19 cells. Scutellarin alleviated the H₂O₂-induced oxidative stress in ARPE-19 cells, which was illustrated by reduced levels of ROS and MDA, accompanied by increased SOD activity and GSH level. The increased apoptosis rate of ARPE-19 cells caused by H₂O₂ induction was significantly decreased after scutellarin treatment. H₂O₂ treatment resulted in significant increase in bax expression and decrease in bcl-2 expression, while the changes in the expressions of bax and bcl-2 were reversed by scutellarin treatment. In addition, scutellarin promoted the activation of JAK2/STAT3 signaling pathway in H₂O₂-induced ARPE-19 cells. Suppression of JAK2/STAT3 signaling pathway abolished the protective effects of scutellarin on H₂O₂-induced ARPE-19 cells.

Conclusion

These findings suggested that scutellarin was capable for alleviating H₂O₂-induced oxidative damage in ARPE-19 cells, which might be ascribed to the activation of JAK2/STAT3 signaling pathway.

Electronic supplementary material

The online version of this article (10.1186/s13578-019-0276-0) contains supplementary material, which is available to authorized users.

Scutellarin suppresses proliferation and promotes apoptosis in A549 lung adenocarcinoma cells via AKT/mTOR/4EBP1 and STAT3 pathways

Background

Scutellarin (SCU), a flavonoid isolated from Erigeron breviscapus (Vant.) Hand.‐Mazz., increases autophagy and apoptosis in the adenocarcinoma A549 cell line, which is resistant to cisplatin. However, whether SCU alone has antitumor activity against non‐small cell lung cancer (NSCLC) is unknown.

Methods

Cell Counting Kit‐8, flow cytometry, colony formation, Hoechst 33258 staining, and Western blot analyses were used to examine the proliferation and apoptosis of A549 cells treated with SCU and the possible molecular mechanisms.

Results

The cell viability assay indicated that SCU markedly suppressed the proliferation of A549 cells in concentration and time‐dependent manners. SCU caused significant G0/G1 phase arrest and apoptosis, as evidenced by flow cytometric analyses, Hoechst 33258 staining, and Western blot analyses of cyclin D1, cyclin E, BCL‐2, cleaved‐caspase‐3, and BAX. Furthermore, SCU treatment reduced the level of pan‐AKT, phosphorylated (p)‐mTOR, mTOR, BCL‐XL, STAT3, and p‐STAT3, and increased the level of 4EBP1.

Conclusions

SCU can suppress proliferation and promote apoptosis in A549 cells through AKT/mTOR/4EBP1 and STAT3 pathways. This suggests that SCU may be developed into a promising antitumor agent for treating NSCLC.

Scutellarin Enhances Antitumor Effects and Attenuates the Toxicity of Bleomycin in H22 Ascites Tumor-Bearing Mice

Bleomycin (BLM) is a broad spectrum anti-tumor drug and inducing pulmonary fibrosis. As an anti-tumor drug without immunosuppression, it is urgent to find a drug that reduces the side effects of BLM. Scutellarin (SCU), a flavone extracted from Erigeron breviscapus (Vant.) Hand-Mazz, has anti-inflammatory activity and ability to inhibit tumor cell growth, migration, and invasion. However, the combined role of SCU and BLM treatment in tumor is unclear. This study aimed to investigate the possible effect and related mechanisms of BLM combined with SCU in the treatment of tumor through in vivo and in vitro experiments. In vivo experiments showed that BLM combined with SCU in the treatment of mice bearing H22 ascites tumor prolonged the survival time, alleviated BLM-induced pulmonary fibrosis, reduced the production of TNF-α; IL-6, and the levels of MDA and MPO. BLM combined with SCU increased the apoptotic rate of H22 ascites cells and the levels of cleaved-caspases-3 and -8. Furthermore, BLM combined with SCU increased the protein expression of p53 and gene expression of miR-29b, and decreased the expression of TGF-β1. In vitro experiment results showed that BLM combined with SCU inhibited the viability of H22 cells and MRC-5 cells, promoted H22 cell apoptosis, up-regulated the protein expression of p53 and down-regulated the protein expression of α-SMA and collagen-I in MRC-5 cells. These experimental results suggested that SCU could enhance the anti-tumor effect of BLM and reduce BLM-induced pulmonary fibrosis, indicating SCU as a potential adjuvant for BLM in the future.

Pine needle oil induces G2/M arrest of HepG2 cells by activating the ATM pathway

Over the last two decades, inducing DNA damage of cancer cells by natural medicines has become a research hotspot in the field of cancer treatment. Although various natural medicines have anticancer effects, very few studies have been conducted to explore the anti-cancer effect of pine needle oil. In the present study, the role of pine needle oil in inducing G2/M arrest in HepG2 cells was investigated. The data revealed that pine needle oil could induce DNA damage in a dose-dependent manner. In the pine needle oil-treated HepG2 cells, the protein levels of phosphorylated (p)-ataxia-telangiectasia mutated (ATM), γ-H2A histone family, member X, p-p53, p-checkpoint kinase 2 and p-cell division cycle 25C were evidently increased, indicating that pine needle oil facilitated G2/M arrest in HepG2 cells through the ATM pathway. In response to the treatment with pine needle oil, ATM was activated in HepG2 cells, which subsequently phosphorylated downstream targets and induced G2/M arrest. In summary, the data of the present study indicated that pine needle oil induces G2/M arrest in HepG2 cells by facilitating ATM activation.

Scutellarin Inhibits Proliferation, Invasion, and Tumorigenicity in Human Breast Cancer Cells by Regulating HIPPO-YAP Signaling Pathway

BACKGROUND The present study aimed to investigate the effects of Scutellarin on proliferation, invasion and tumorigenicity in human breast carcinoma MCF-7 cells and its associated molecular mechanisms. MATERIAL AND METHODS The MCF-7 cells were cultured with varies of concentrations of Scutellarin in vitro. The proliferation, invasion, and apoptosis of MCF-7 cells were studied via CCK-8 assay, transwell assay, and flow cytometry. In vivo expression of the HIPPO pathway key proteins YAP and p-YAP of MCF-7 cells were analyzed by immunohistochemistry. RESULTS The inhibition rates of Scutellarin-treated MCF-7 cells were 40.1%, 58.7%, and 70.6% for 24, 48, and 72 h, respectively. The MCF-7 cell proliferation was significantly inhibited by Scutellarin. Treating MCF-7 cells with Scutellarin led to invasion inhibition. The rates apoptotic cells were between 12.4±1.9% and 23.9±2.1% in 40-120 µM Scutellarin-administrated groups, which had a significant rise compared with the control group (7.8±1.9%, P<0.05). Scutellarin significantly inhibited MCF-7 xenograft tumor growth. Immunohistochemical analysis showed that the inhibition of tumor growth in Scutellarin-treated mice was associated with increased p-YAP and decreased YAP expression in vivo. CONCLUSIONS Scutellarin-treated breast carcinoma MCF-7 cells had significantly inhibited growth and induced apoptosis, which is associated with induction of autophagy through regulation of the HIPPO-YAP signaling pathway, providing support to the clinical use of Scutellarin-based medication to achieve optimized outcome in patients with breast carcinoma.

Enhancement of scutellarin oral delivery efficacy by vitamin B12-modified amphiphilic chitosan derivatives to treat type II diabetes induced-retinopathy

BACKGROUND

Diabetic retinopathy is the most common complication in diabetic patients relates to high expression of VEGF and microaneurysms. Scutellarin (Scu) turned out to be effective against diabetes related vascular endothelial cell dysfunction. However, its clinical applications have been limited by its low bioavailability. In this study, we formulated and characterized a novel intestinal target nanoparticle carrier based on amphiphilic chitosan derivatives (Chit-DC-VB12) loaded with scutellarin to enhance its bioavailability and then evaluated its therapeutic effect in experimental diabetic retinopathy model.

RESULTS

Chit-DC-VB12 nanoparticles showed low toxicity toward the human colon adenocarcinoma (Caco-2) cells and zebra fish within concentration of 250 μg/ml, owing to good biocompatibility of chitosan. The scutellarin-loaded Chit-DC-VB12 nanoparticles (Chit-DC-VB12-Scu) were then prepared by self-assembly in aqueous solution. Scanning electron microscopy and dynamic light scattering analysis indicated that the Chit-DC-VB12-Scu nanoparticles were spherical particles in the sizes ranging from 150 to 250 nm. The Chit-DC-VB12-Scu nanoparticles exhibited high permeation in Caco-2 cell, indicated it could be beneficial to be absorbed in humans. We also found that Chit-DC-VB12 nanoparticles had a high cellular uptake. Bioavailability studies were performed in Sprague-Dawley rats, which present the area under the curve of scutellarin of Chit-DC-VB12-Scu was two to threefolds greater than that of free scutellarin alone. Further to assess the therapeutic efficacy of diabetic retinopathy, we showed Chit-DC-VB12-Scu down-regulated central retinal artery resistivity index and the expression of angiogenesis proteins (VEGF, VEGFR2, and vWF) of retinas in type II diabetic rats.

CONCLUSIONS

Chit-DC-VB12 nanoparticles loaded with scutellarin have better bioavailability and cellular uptake efficiency than Scu, while Chit-DC-VB12-Scu nanoparticles alleviated the structural disorder of intraretinal neovessels in the retina induced by diabetes, and it also inhibited the retinal neovascularization via down-regulated the expression of angiogenesis proteins. In conclusion, the Chit-DC-VB12 nanoparticles enhanced scutellarin oral delivery efficacy and exhibited potential as small intestinal target promising nano-carriers for treatment of type II diabetes induced-retinopathy.

Scutellarin as a Potential Therapeutic Agent for Microglia-Mediated Neuroinflammation in Cerebral Ischemia

The cerebral ischemia is one of the most common diseases in the central nervous system that causes progressive disability or even death. In this connection, the inflammatory response mediated by the activated microglia is believed to play a central role in this pathogenesis. In the event of brain injury, activated microglia can clear the cellular debris and invading pathogens, release neurotrophic factors, etc., but in chronic activation microglia may cause neuronal death through the release of excessive inflammatory mediators. Therefore, suppression of microglial over-reaction and microglia-mediated neuroinflammation is deemed to be a therapeutic strategy of choice for cerebral ischemic damage. In the search for potential herbal extracts that are endowed with the property in suppressing the microglial activation and amelioration of neuroinflammation, attention has recently been drawn to scutellarin, a Chinese herbal extract. Here, we review the roles of activated microglia and the effects of scutellarin on activated microglia in pathological conditions especially in ischemic stroke. We have further extended the investigation with special reference to the effects of scutellarin on Notch signaling, one of the several signaling pathways known to be involved in microglial activation. Furthermore, in light of our recent experimental evidence that activated microglia can regulate astrogliosis, an interglial "cross-talk" that was amplified by scutellarin, it is suggested that in designing of a more effective therapeutic strategy for clinical management of cerebral ischemia both glial types should be considered collectively.

Preventive and Therapeutic Effects of Chinese Herbal Compounds against Hepatocellular Carcinoma

Traditional Chinese Medicines, unique biomedical and pharmaceutical resources, have been widely used for hepatocellular carcinoma (HCC) prevention and treatment. Accumulated Chinese herb-derived compounds with significant anti-cancer effects against HCC have been identified. Chinese herbal compounds are effective in preventing carcinogenesis, inhibiting cell proliferation, arresting cell cycle, inducing apoptosis, autophagy, cell senescence and anoikis, inhibiting epithelial-mesenchymal transition, metastasis and angiogenesis, regulating immune function, reversing drug resistance and enhancing the effects of chemotherapy in HCC. This paper comprehensively reviews these compounds and their effects on HCC. Finally, the perspectives and rational application of herbal compounds for HCC management are discussed.

Scutellarin Reduces Endothelium Dysfunction through the PKG-I Pathway

Purpose. In this report, we investigated the protective mechanism of scutellarin (SCU) in vitro and in vivo which could be involved in endothelial cGMP-dependent protein kinase (PKG), vasodilator stimulated phosphoprotein (VASP) pathway, and vascular endothelium dysfunction (EtD). Method. Human brain microvascular endothelial cells (HBMECs) with hypoxia reoxygenation (HR) treatment and rats with cerebral ischemia reperfusion (CIR) treatment were applied. Protein and mRNA expression of PKG, VASP, and p-VASP were evaluated by Western blot and RT-PCR methods. Vascular EtD was assessed by using wire myography to determine endothelium-dependent vasorelaxation in isolated rat basilar artery (BA). Result. In cultured HBMECs, SCU (0.1, 1, and 10 μM) increased cell viability, mRNA, protein level, and phosphorylative activity of PKG and VASP against HR injury. In HR model of BA, SCU increased protein level of P-VASP. In rat CIR model, wire myography demonstrated that SCU (45 and 90 mg/kg, i.v.) significantly reduced ischemic size by partially restoring the endothelium dependent vasodilation of BA; PKG inhibitor Rp-8-Br-cGMPS (50 μg/kg, i.v.) reversed this protection of SCU in CIR rats. Conclusion. SCU protects against cerebral vascular EtD through endothelial PKG pathway activation.

In vitro inhibitory effects of scutellarin on six human/rat cytochrome P450 enzymes and P-glycoprotein

Inhibition of cytochrome P450 (CYP) and P-glycoprotein (P-gp) are regarded as the most frequent and clinically important pharmacokinetic causes among the various possible factors for drug-drug interactions. Scutellarin is a flavonoid which is widely used for the treatment of cardiovascular diseases. In this study, the in vitro inhibitory effects of scutellarin on six major human CYPs (CYP1A2, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP3A4) and six rat CYPs (CYP1A2, CYP2C7, CYP2C11, CYP2C79, CYP2D4, and CYP3A2) activities were examined by using liquid chromatography-tandem mass spectrometry. Meanwhile, the inhibitory effects of scutellarin on P-gp activity were examined on a human metastatic malignant melanoma cell line WM-266-4 by calcein-AM fluorometry screening assay. Results demonstrated that scutellarin showed negligible inhibitory effects on the six major CYP isoenzymes in human/rat liver microsomes with almost all of the IC50 values exceeding 100 μM, whereas it showed values of 63.8 μM for CYP2C19 in human liver microsomes, and 63.1 and 85.6 μM for CYP2C7 and CYP2C79 in rat liver microsomes, respectively. Scutellarin also showed weak inhibitory effect on P-gp. In conclusion, this study demonstrates that scutellarin is unlikely to cause any clinically significant herb-drug interactions in humans when co-administered with substrates of the six CYPs (CYP1A2, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP3A4) and P-gp.

Understanding the polypharmacological anticancer effects of Xiao Chai Hu Tang via a computational pharmacological model

Xiao Chai Hu Tang (XCHT), a traditional herbal formula, is widely administered as a cancer treatment. However, the underlying molecular mechanisms of its anticancer effects are not fully understood. In the present study, a computational pharmacological model that combined chemical space mapping, molecular docking and network analysis was employed to predict which chemical compounds in XCHT are potential inhibitors of cancer-associated targets, and to establish a compound-target (C-T) network and compound-compound (C-C) association network. The identified compounds from XCHT demonstrated diversity in chemical space. Furthermore, they occupied regions of chemical space that were the same, or close to, those occupied by drug or drug-like compounds that are associated with cancer, according to the Therapeutic Targets Database. The analysis of the molecular docking and the C-T network demonstrated that the potential inhibitors possessed the properties of promiscuous drugs and combination therapies. The C-C network was classified into four clusters and the different clusters contained various multi-compound combinations that acted on different targets. The study indicated that XCHT has a polypharmacological role in treating cancer and the potential inhibitory components of XCHT require further investigation as potential therapeutic strategies for cancer patients.