Luteolin from Flos Chrysanthemi and its derivatives: New small molecule Bcl-2 protein inhibitors

Binary Nanodrug-Delivery System Designed for Leukemia Therapy: Aptamer- and Transferrin-Codecorated Daunorubicin- and Luteolin-Coloaded Nanoparticles

Objective

This study aimed to develop a binary nanodrug-delivery system decorated with aptamers (APs) and transferrin (Tf) and loaded with daunorubicin (Drn) and luteolin (Lut) for the treatment of leukemia.

Methods

Oligonucleotide AP- and Tf-contaiing ligands were designed and synthesized separately. AP-decorated Drn-loaded nanoparticles (AP-Drn NPs) and Tf-Lut NPs were prepared by self-assembly. An AP- and Tf-codecorated Drn- and Lut-coloaded nanodrug-delivery system (AP/Tf-Drn/Lut NPs) was prepared by self-assembly of AP-Drn NPs and Tf-Lut NPs. In vitro and in vivo efficiency of the system was evaluated on leukemia cell line and cell-bearing mouse model in comparison with single ligand-decorated, single drug-loaded and free-drug formulations.

Results

AP/Tf-Drn/Lut NPs were spherical and nanosized (187.3±5.3 nm) and loaded with about 85% of drugs. In vitro cytotoxicity of AP/Tf-Drn/Lut NPs was remarkably higher than single ligand-decorated ones. Double drug-loaded AP/Tf-Drn/Lut NPs exhibited higher tumor-cell inhibition than single drug-loaded ones, which showed a synergic effect of the two drugs. AP/Tf-Drn/Lut NPs achieved the most efficient antileukemic activity and absence of toxicity in vivo.

Conclusion

The present study showed that AP/Tf-Drn/Lut NPs are a promising drug-delivery system for targeted treatment of leukemia, due to the synergic effect of the two drugs in this system. The limitations of this system include stability during large-scale production and application from bench to bedside.

Study on the chemical profile of chrysanthemum and the evaluation of the similarities and differences between different cultivars

Chrysanthemum originates in China and has been cultivated for tea and food utilizations over 2 thousand years. According to differences in origin and processing methods, Chrysanthemum morifolium Ramat. can be categorized into many cultivars. This study aims to investigate the chemical components of chrysanthemum and clarify the similarities and differences between different chrysanthemum varieties. A total of 55 non-volatile components and 66 volatile components in chrysanthemum were identified by ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS) and gas chromatography-mass spectrometry (GC-MS) methods, respectively. A rapid UPLC-MS/MS method was developed and validated for the simultaneous determination of 13 active components in 30 batches chrysanthemum samples of ten different cultivars. Multivariate statistical techniques were applied to analyze the samples. The result indicated that Boju, Huaiju and Chuju were more similar in terms of the ingredient content and Qiju, Jinsihuangju, Huangju, Hangju, Gongju, Fubaiju, Baiju have a high degree of similarity. Furthermore, isochlorogenic acid C, luteolin, apigenin-7-glucoside, chlorogenic acid, apigenin and cryptochlorogenic acid plays an important role in distinguishing different varieties of chrysanthemum. The established strategy explains the similarities and differences between different varieties of chrysanthemums to some extent, and provides certain reference value for the choice of chrysanthemums for eating or medicinal purposes in daily life.

Protective effect of cynaroside on sepsis-induced multiple organ injury through Nrf2/HO-1-dependent macrophage polarization

Cynaroside is the primary flavonoid component of honeysuckle which has been widely used as Chinese traditional medicine given its anti-inflammation properties. Overactive systemic inflammatory response and multi-organ injury are the leading causes of life-threatening sepsis. Regulation of macrophage polarization balance may act as a promising strategy for its treatment. In the present study, we aimed to investigate whether cynaroside exerted protective effects against sepsis and its potential mechanism. Building upon a sepsis mouse model, we observed cynaroside alleviated serum levels of inflammatory factors including IL-1β and TNF-α at 5 and 10 mg/kg. The pathological injury of heart, kidney and lung was remarkedly attenuated as the levels of blood urea nitrogen, creatinine, creatine kinase-MB and lactate dehydrogenase were reduced nearly 2.8-, 2.7-, 2.4-, and 2.5-fold as compared with the sepsis mice, respectively. We further demonstrated cynaroside suppressed the biomarker of pro-inflammatory macrophage M1 phenotype (iNOS+) and promotes the anti-inflammatory M2 polarization (CD206+) in the injury organs of septic mice. Mechanistic research verified cynaroside inhibited LPS-induced polarization of macrophage into M1 phenotype, which can be highly blocked by Nrf2 inhibitor. Expectedly, Nrf2 and its downstream (Heme oxygenase-1 (HO-1)) was upregulated in injury organs after treating with cynaroside, indicating the involvement of Nrf2 signaling. Taken together, the data claims cynaroside ameliorated systematic inflammation and multi-organ injury dependent on Nrf2/HO-1 pathway in septic mice.

Luteolin Prevents Cardiac Dysfunction and Improves the Chemotherapeutic Efficacy of Doxorubicin in Breast Cancer

Background: Doxorubicin (Dox) is one of the most effective chemotherapy agents used in the treatment of solid tumors and hematological malignancies. However, it causes dose-related cardiotoxicity that may lead to heart failure in patients. Luteolin (Lut) is a common flavonoid that exists in many types of plants. It has been studied for treating various diseases such as hypertension, inflammatory disorders, and cancer. In this study, we evaluated the cardioprotective and anticancer effects of Lut on Dox-induced cardiomyopathy in vitro and in vivo to explore related mechanisms in alleviating dynamin-related protein (Drp1)-mediated mitochondrial apoptosis.

Methods: MTT and LDH assay were used to determine the viability and toxicity of cardiomyocytes treated with Dox and Lut. Flow cytometry was used to examine ROS levels, and electron and confocal microscopy was employed to assess the mitochondrial morphology. The level of apoptosis was examined by Hoechst 33258 staining. The protein levels of myocardial fission protein and apoptosis-related protein were examined using Western blot. Transcriptome analysis of the protective effect of Lut against Dox-induced cardiac toxicity in myocardial cells was performed using RNA sequencing technology. The protective effects of Lut against cardiotoxicity mediated by Dox in zebrafish were quantified. The effect of Lut increase the antitumor activity of Dox in breast cancer both in vitro and in vivo were further employed.

Results: Lut ameliorated Dox-induced toxicity in H9c2 and AC16 cells. The level of oxidative stress was downregulated by Lut after Dox treatment of myocardial cells. Lut effectively reduced the increased mitochondrial fission post Dox stimulation in cardiomyocytes. Apoptosis, fission protein Drp1, and Ser616 phosphorylation were also increased post Dox and reduced by Lut. In the zebrafish model, Lut significantly preserved the ventricular function of zebrafish after Dox treatment. Moreover, in the mouse model, Lut prevented Dox-induced cardiotoxicity and enhanced the cytotoxicity in triple-negative breast cancer by inhibiting proliferation and metastasis and inducing apoptosis.

Chrysanthemum ethanol extract induced loss of Kupffer cells via the mitochondria-dependent apoptotic pathway

Chrysanthemum has been viewed as an important traditional Chinese medicine (TCM) with a long history. Research studies indicated many potential pharmaceutical effects of chrysanthemum extract. However, hardly any investigation has been performed to describe its toxicity. In this study, acute application of chrysanthemum ethanol extract (CEE, 300 mg kg^-1) was found to induce apoptosis of hepatic Kupffer cells in vivo. CEE was also observed to induce apoptosis of RAW264.7 cells in a dose- and time-dependent manner. Further analysis using flow cytometry and western blotting revealed that CEE induced apoptosis of RAW264.7 cells via a mitochondria-dependent pathway. After a HPLC combined screening assay, we narrowed down the toxicity caused by the petroleum extract of CEE (CEE-PE, 66 μg mL^-1). In vivo effects of CEE-PE were also tested in mice. Additionally, nine potential toxic compounds were isolated and identified from CEE-PE. In all, we found that components with small polarities in CEE could induce apoptosis of Kupffer cells and macrophages via a mitochondrial dependent pathway, which might draw attention to the safety issues of everyday use of chrysanthemum.

Pharmacokinetic Study of Thirteen Ingredients after the Oral Administration of Flos Chrysanthemi Extract in Rats by UPLC-MS/MS

A rapid and reliable UPLC-MS/MS method was developed and validated for the simultaneous quantification of thirteen bioactive compounds (luteolin, cynaroside, luteolin 7-O-glucuronide, isochlorogenic acid C, chlorogenic acid, cryptochlorogenic acid, apigenin, apigenin 7-glucoside, acacetin, hyperoside, isoquercitrin, tilianin, and hesperidin) in rat plasma. The compounds were separated on an ACQUITY UPLC BEH C₁₈ column (2.1 × 100 mm, 1.7 μm) with a gradient mobile phase system of acetonitrile and 0.1% (v/v) formic acid aqueous solution at a flow rate of 0.3 mL/min. All compounds were quantitated using Agilent Jet Stream electrospray ionization (AJS ESI) in a negative ion mode. The lower limit of quantification (LLOQ) for all compounds was below 5 ng/mL. The intra- and interday accuracy ranged from -13.0% to 14.0%, and precisions were less than 12.2%. The extraction recoveries of the compounds were in the range of 56.9% to 95.0%, and the matrix effect ranged between 71.6% and 109.3%. Stability studies proved that the thirteen compounds were stable under tested conditions, with a relative standard deviation (RSD) of less than 11.4%. This developed method was successfully applied to the pharmacokinetic study of the 13 bioactive compounds after oral administration of Flos Chrysanthemi extract in rat by UPLC-MS/MS. Pharmacokinetic parameters of 8 out of the 13 compounds investigated are presented in this paper.

An integration of UPLC-DAD/ESI-Q-TOF MS, GC-MS, and PCA analysis for quality evaluation and identification of cultivars of Chrysanthemi Flos (Juhua)

BACKGROUND

Chrysanthemi Flos (CF), as a popular traditional Chinese medicine (TCM), has five main cultivars in China, namely "Chuju", "Boju", "Gongju", "Huaiju" and "Hangju". Due to their habitats and processing methods, great quality variations occur yet no systematical study has ever been carried out to evaluate such variations.

PURPOSE

In this study, we aim to establish a new approach that can serve both as a quality control method and as an identification method for cultivars of CF.

METHOD

The components in CF samples were identified by a combination of UPLC-ESI-Q-TOF/MS and GC/MS. Furthermore, a multimodal quantitative method was established by UPLC-UV coupled with principal component analysis (PCA) and the similarity evaluation system (SES), which was used to control and identify four cultivars of CF.

RESULTS

18 compounds of flavonoids and caffeoylquinic acids were identified and ten of them were quantified using UPLC-ESI-Q-TOF/MS. Different cultivars of CF could be clearly distinguished with the fingerprints evaluation and principal component analysis (PCA). A total of 74 volatile compounds were detected by GC/MS. The distinctness of volatile components was observed. By the combination of UPLC-ESI-Q-TOF/MS and GC/MS, an identification and quality control method for CF was successfully established.

CONCLUSION

The combination of UPLC-ESI-Q-TOF/MS and GC/MS could act as a comprehensive multimodal method for both identification and quality control of herbal medicines. This study provided new insights into the overall evaluation method for herbal medicines possessing different cultivars.

Luteolin sensitizes the antitumor effect of cisplatin in drug-resistant ovarian cancer via induction of apoptosis and inhibition of cell migration and invasion

Luteolin, a polyphenolic flavone, has been demonstrated to exert anti-tumor activity in various cancer types. Cisplatin drug resistance is a major obstacle in the management of ovarian cancer. In the present study, we investigated the chemo-sensitizing effect of luteolin in both cisplatin-resistant ovarian cancer cell line and a mice xenotransplant model. In vitro, CCK-8 assay showed that luteolin inhibited cell proliferation in a dose-dependent manner, and luteolin enhanced anti-proliferation effect of cisplatin on cisplatin-resistant ovarian cancer CAOV3/DDP cells. Flow cytometry revealed that luteolin enhanced cell apoptosis in combination with cisplatin. Western blotting and qRT-PCR assay revealed that luteolin increased cisplatin-induced downregulation of Bcl-2 expression. In addition, wound-healing assay and Matrigel invasion assay showed that luteolin and cisplatin synergistically inhibited migration and invasion of CAOV3/DDP cells. Moreover, in vivo, luteolin enhanced cisplatin-induced reduction of tumor growth as well as induction of apoptosis. We suggest that luteolin in combination with cisplatin could potentially be used as a new regimen for the treatment of ovarian cancer.

Stimulation of Fas/FasL-mediated apoptosis by luteolin through enhancement of histone H3 acetylation and c-Jun activation in HL-60 leukemia cells

Luteolin (3',4',5,7-tetrahydroxyflavone), which exists in fruits, vegetables, and medicinal herbs, is used in Chinese traditional medicine for treating various diseases, such as hypertension, inflammatory disorders, and cancer. However, the gene-regulatory role of luteolin in cancer prevention and therapy has not been clarified. Herein, we demonstrated that treatment with luteolin resulted in a significant decrease in the viability of human leukemia cells. In the present study, by evaluating fragmentation of DNA and poly (ADP-ribose) polymerase (PARP), we found that luteolin was able to induce PARP cleavage and nuclear fragmentation as well as an increase in the sub-G₀ /G₁ fraction. In addition, luteolin also induced Fas and Fas ligand (FasL) expressions and subsequent activation of caspases-8 and -3, which can trigger the extrinsic apoptosis pathway, while knocking down Fas-associated protein with death domain (FADD) prevented luteolin-induced PARP cleavage. Immunoblot and chromatin immunoprecipitation (ChIP) analyses revealed that luteolin increased acetylation of histone H3, which is involved in the upregulation of Fas and FasL. Moreover, both the extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) pathways are involved in luteolin-induced histone H3 acetylation. Finally, luteolin also activated the c-Jun signaling pathway, which contributes to FasL, but not Fas, gene expression and downregulation of c-Jun expression by small interfering RNA transfection which resulted in a significant decrease in luteolin-induced PARP cleavage. Thus, our results demonstrate that luteolin induced apoptosis of HL-60 cells, and this was associated with c-Jun activation and histone H3 acetylation-mediated Fas/FasL expressions.

Natural and Synthetic Flavonoids: Structure-Activity Relationship and Chemotherapeutic Potential for the Treatment of Leukemia

Flavonoids and their derivatives are polyphenolic secondary metabolites with an extensive spectrum of pharmacological activities, including antioxidants, antitumor, anti-inflammatory, and antiviral activities. These flavonoids can also act as chemopreventive agents by their interaction with different proteins and can play a vital role in chemotherapy, suggesting a positive correlation between a lower risk of cancer and a flavonoid-rich diet. These agents interfere with the main hallmarks of cancer by various individual mechanisms, such as inhibition of cell growth and proliferation by arresting the cell cycle, induction of apoptosis and differentiation, or a combination of these mechanisms. This review is an effort to highlight the therapeutic potential of natural and synthetic flavonoids as anticancer agents in leukemia treatment with respect to the structure-activity relationship (SAR) and their molecular mechanisms. Induction of cell death mechanisms, production of reactive oxygen species, and drug resistance mechanisms, including p-glycoprotein efflux, are among the best-described effects triggered by the flavonoid polyphenol family.

Luteolin inhibited proliferation and induced apoptosis of prostate cancer cells through miR-301

Luteolin is a falvonoid compound derived from Lonicera japonica Thunb. Numerous reports have demonstrated that luteolin has anticancer effects on many kinds of tumors. This study investigated the effects of luteolin on prostate cancer (PCa), assessing the PC3 and LNCaP cells. The cell viability and apoptosis were assessed by performing Cell Counting Kit-8 assay and Annexin V–fluorescein isothiocyanate/propidium iodide double staining. Luteolin was found to inhibit androgen-sensitive and androgen-independent PCa cell lines’ growth and induced apoptosis. To uncover the exact mechanisms and molecular targets, microRNA (miR) array analysis was performed. miR-301 was found to be markedly downregulated. Then, the expression of miR-301 was retrospectively analyzed in the primary PCa tissues by quantitative reverse transcription polymerase chain reaction and in situ hybridization methods. According to the quantitative reverse transcription polymerase chain reaction results of miR-301, the 54 PCa patients were divided into two groups: high and low miR-301 groups. The division indicator is a relative expression ≥5. Compared to the low-expression group, high miR-301 expression was associated with a significantly shorter overall survival (P=0.029). The proapoptotic gene, DEDD2, was predicted to be the direct target of miR-301. It was clarified in accordance with bioinformatics and luciferase activity analyses. The overexpression of miR-301 by plasmid decreased the luteolin effect. Taken together, these results suggest that luteolin inhibits PCa cell proliferation through miR-301, the poor predictive factor of PCa.